bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between suicide ideation and attempts, bully victimization, dating violence, and depressive symptoms among Black and Hispanic youth
Authors: Opara Ijeoma , Weerakoon Sitara M. , Brooks Stephens Jasmin R. , Choe Taylor , Gunn John F. , Thrasher Shawndaya S.
Published: November 2023

Background

Suicide rates among Black and Hispanic youth have been increasing over the past decade in the United States. The objective of this study was to identify risk factors for suicide ideation and attempt among Black and Hispanic youth in the United States using intersectionality theory and minority stress theory as a framework.

Methods

Data from the CDC Youth Risk Behavior Surveillance System (YRBSS; 2015–2019) were analyzed and delimited to include only Black and Hispanic youth.

Results

About 37% of the subsample identified as Black and 63% of the subsample identified as Hispanic; mean age was 16 years (SE = 0.02). Weighted multivariate logistic regressions were used to explore associations between suicide ideation and attempt, depressive symptoms, bullying, dating violence, and being threatened with a weapon. Black and Hispanic youth who had depressive symptoms, experienced bullying, dating violence, or threatened with a weapon all had increased odds of having suicide ideation and suicide attempt. Hispanic youth had the higher odds of suicide ideation and attempt than Black youth. Girls in the study also had elevated odds of suicide ideation.

Conclusion

This study adds to the literature on risk factors of suicide in Black and Hispanic youth and bringing to awareness the gender disparities in suicide ideation and attempt among youth.
Chinese children show racial and skin‐tone salience but little color evasion
Authors: Gao Dan , van Geel Mitch , Liu Junsheng , Mesman Judi
Published: November 2023

Children may notice racial differences (i.e., show racial and/or skin‐tone salience), but deliberately avoid mentioning such differences (i.e., color evasion) with increasing age. This contradiction may be due to prevailing egalitarian social norms about race. Color evasion is understudied among children in China. In a sample of 155 Chinese children (71 girls and 84 boys) aged 7–11 years from urban regions of China, we collected measures of children's racial and/or skin‐tone salience and color evasion as well as their attitudes toward light‐skinned East Asian, tan‐skinned East Asian, and White groups. Analyses revealed that racial differences were salient to Chinese children, and that they showed little color evasion. Skin tone was most salient in children's categorization performance. We found a preference hierarchy where light‐skinned East Asian people were favored most, and White people least. Color evasion was negatively related to Chinese children's positive attitudes toward White people. The findings emphasize the importance of social contexts in shaping children's racial attitudes.
The mice plague and the assemblage of beastly landscapes in regional and rural Australia
Authors: Randell‐Moon Holly
Published: November 2023

Beginning in the spring of 2020, a mouse and rat plague spread across the rural grain belt in New South Wales, Australia. Lasting for almost 10 months, the plague was described by the local media as a ‘horror’ which ‘terrorised’ farmers and ‘ravaged’ farms. Focusing predominantly on news media reporting of the plague, this article shows how the mice and rats were constructed as abject matter out of place. This construction reveals how the interspecies dynamics of managing pests render rural landscapes vulnerable and unsettle colonial imaginaries regarding the management of the Australian environment. The plague signals a disturbance of the ‘natural’ order of things where the landscape is ‘normally’ anthropocentrically managed for monocultural farming. Drawing on Chris Philo and Chris Wilbert's identification of ‘beastly spaces’, this article explores the plague as facilitating a beastly landscape that radically de‐centres human control and investment in the environment.
Lyme rashes disease classification using deep feature fusion technique
Authors: Ali Ghulam , Anwar Muhammad , Nauman Muhammad , Faheem Muhammad , Rashid Javed
Published: November 2023

Automatic classification of Lyme disease rashes on the skin helps clinicians and dermatologists’ probe and investigate Lyme skin rashes effectively. This paper proposes a new in‐depth features fusion system to classify Lyme disease rashes. The proposed method consists of two main steps. First, three different deep learning models, Densenet201, InceptionV3, and Exception, were trained independently to extract the deep features from the erythema migrans (EM) images. Second, a deep feature fusion mechanism (meta classifier) is developed to integrate the deep features before the final classification output layer. The meta classifier is a basic deep convolutional neural network trained on original images and features extracted from base level three deep learning models. In the feature fusion mechanism, the last three layers of base models are dropped out and connected to the meta classifier. The proposed deep feature fusion method significantly improved the classification process, where the classification accuracy was 98.97%, which is particularly impressive than the other state‐of‐the‐art models.
The apocarotenoid β‐ionone regulates the transcriptome of Arabidopsis thaliana and increases its resistance against Botrytis cinerea
Authors: Felemban Abrar , Moreno Juan C. , Mi Jianing , Ali Shawkat , Sham Arjun , AbuQamar Synan F. , Al‐Babili Salim
Published: November 2023

Carotenoids are isoprenoid pigments indispensable for photosynthesis. Moreover, they are the precursor of apocarotenoids, which include the phytohormones abscisic acid (ABA) and strigolactones (SLs) as well as retrograde signaling molecules and growth regulators, such as β‐cyclocitral and zaxinone. Here, we show that the application of the volatile apocarotenoid β‐ionone (β‐I) to Arabidopsis plants at micromolar concentrations caused a global reprogramming of gene expression, affecting thousands of transcripts involved in stress tolerance, growth, hormone metabolism, pathogen defense, and photosynthesis. This transcriptional reprogramming changes, along with induced changes in the level of the phytohormones ABA, jasmonic acid, and salicylic acid, led to enhanced Arabidopsis resistance to the widespread necrotrophic fungus Botrytis cinerea (B.c.) that causes the gray mold disease in many crop species and spoilage of harvested fruits. Pre‐treatment of tobacco and tomato plants with β‐I followed by inoculation with B.c. confirmed the effect of β‐I in increasing the resistance to this pathogen in crop plants. Moreover, we observed reduced susceptibility to B.c. in fruits of transgenic tomato plants overexpressing LYCOPENE β‐CYCLASE, which contains elevated levels of endogenous β‐I, providing a further evidence for its effect on B.c. infestation. Our work unraveled β‐I as a further carotenoid‐derived regulatory metabolite and indicates the possibility of establishing this natural volatile as an environmentally friendly bio‐fungicide to control B.c.
Acetylation of homogalacturonan and rhamnogalacturonan‐I is catalyzed by a suite of trichome birefringence‐like proteins
Authors: Zhong Ruiqin , Cui Dongtao , Richardson Elizabeth A. , Ye Zheng‐Hua
Published: November 2023

Plant cell wall polysaccharides, including xylan, mannan, xyloglucan, and pectins, are often acetylated and members of the domain of unknown function 231 (DUF231)/trichome birefringence‐like (TBL) family have been shown to be O‐acetyltransferases mediating the acetylation of xylan, mannan, and xyloglucan. However, little is known about the O‐acetyltransferases responsible for pectin acetylation. In this report, we biochemically characterized a suite of Arabidopsis DUF231/TBL proteins for their roles in pectin acetylation. We generated 24 TBL recombinant proteins in mammalian cells and demonstrated that 10 of them were able to transfer acetyl groups from acetyl‐CoA onto the pectins homogalacturonan (HG) or rhamnogalacturonan‐I (RG‐I), and thus were named pectin O‐acetyltransferase 1 to 10 (POAT1 to 10). It was found that POAT2,4,9,10 specifically acetylated HG and POAT5,6 acetylated RG‐I, whereas POAT1,3,7,8 could act on both HG and RG‐I. The acetylation of HG and RG‐I by POATs was further corroborated by hydrolysis with pectin acetylesterases and by nuclear magnetic resonance spectroscopy. In addition, mutations of the conserved GDS and DXXH motifs in POAT3 and POAT8 were shown to lead to a loss of their ability to acetylate HG and RG‐I. Furthermore, simultaneous RNA interference downregulation of POAT1,3,6,7,8 resulted in reduced cell expansion, impaired plant growth, and decreased pectin acetylation. Together, our findings indicate that these POATs are pectin O‐acetyltransferases involved in acetylation of the pectin polysaccharides HG and RG‐I.
Adjunctive fixation of the humeral epicondyle in a lateral condylar fracture model: Ex vivo comparison of pins and plates with a novel composite (AdhFix)
Authors: Quinn Robert J. , Höglund Odd V. , Hutchinson Daniel J. , Opande Lola , Lim Edward , Birgersson Ulrik , Granskog Viktor , Malkoch Michael
Published: November 2023

Objective

To compare the biomechanical properties of using a novel composite construct (AdhFix) to an interfragmentary Kirschner wire or a reconstruction plate as adjunctive epicondylar stabilization in simulated lateral unicondylar humeral fractures.

Study design

Cadaveric biomechanical assessment.

Sample population

Paired humeri harvested from skeletally mature dogs (14–41 kg), nine cadavers per group.

Methods

Simulated lateral unicondylar humeral fractures were stabilized with a transcondylar 4.5 mm cortical screw placed in lag fashion. Adjunct fixations consisting of a novel composite incorporating 2.7 mm cortical screws on one side, and either a 2.7 mm reconstruction plate or a 1.6 mm Kirschner wire on the contralateral side, were tested within paired humeri. Repaired humeri were axially loaded to failure and construct stiffness, yield load, and ultimate load were obtained from the load‐deformation curves.

Results

In pairwise comparison, yield load was significantly higher for AdhFix group compared to the pin group, p = .016. No statistical significance was seen in the comparison between AdhFix group and the plate group, p = .25.

Conclusion

Adhfix was mechanically superior to K‐wires, and comparable to plate fixation, for adjunctive fixation in a lateral humeral condylar model. Our results support further investigation of the novel composite for adjunct fracture fixation in lateral humeral condylar fractures.

Clinical significance

The novel composite tested may be a viable alternative for adjunct fixation of humeral condylar fractures, a technique that circumvents plate contouring.
Realising residually finite groups as subgroups of branch groups
Authors: Kionke Steffen , Schesler Eduard
Published: November 2023

We prove that every finitely generated, residually finite group embeds into a finitely generated perfect branch group such that many properties of are preserved under this embedding. Among those are the properties of being torsion, being amenable and not containing a non‐abelian free group. As an application, we construct a finitely generated, non‐amenable torsion branch group.
Reacting Flow Prediction of the Low-Swirl Lifted Flame in an Aeronautical Combustor With Angular Air Supply
Authors: Hoffmann Sven , Koch Rainer , Bauer Hans-Jörg
Published: November 2023

The development of lean-burn combustion systems is of paramount importance for reducing the pollutant emissions of future aero engine generations. By tilting the burners of an annular combustor in circumferential direction relative to the rotational axis of the engine, the potential of increased combustion stability is opened up due to an enhanced exhaust gas recirculation between adjacent flames. The innovative gas turbine combustor concept, called the short helical combustor (SHC), allows the main reaction zone to be operated at low equivalence ratios. To exploit the higher stability of the fuel-lean combustion, a low-swirl lifted flame is implemented in the staggered SHC burner arrangement. The objective is to reach ultralow NOx emissions by complete evaporation and extensive premixing of fuel and air upstream of the lean reaction zone. In this work, a modeling approach is developed to investigate the characteristics of the lifted flame in an enclosed single-burner configuration, using the gaseous fuel methane. It is demonstrated that by using the large eddy simulation method, the shape and liftoff height of the flame are adequately reproduced by means of the finite-rate chemistry approach. For the numerical prediction of the lean lifted flame in the SHC arrangement, the focus is on the interaction of adjacent burners. It is shown that the swirling jet flow is deflected toward the sidewall of the staggered combustor dome, which is attributed to the asymmetrical confinement. Since the stabilization mechanism of the low-swirl flame relies on outer recirculation zones, the upstream transport of hot combustion products back to the flame base is studied by the variation of the combustor confinement ratio. It turns out that increasing the combustor size amplifies the exhaust gas recirculation along the sidewall, and increases the temperature of recirculating burned gases. This study emphasizes the capability of the proposed lean-burn combustor concept for future aero engine applications.
Advanced Modeling of Flow and Heat Transfer in Rotating Disk Cavities Using Open-Source Computational Fluid Dynamics
Authors: Wang Ruonan , Gao Feng , Chew John W. , Marxen Olaf , Sun Zixiang
Published: November 2023

Code_Saturne, an open-source computational fluid dynamics (CFD) code, has been applied to a range of problems related to turbomachinery internal air systems. These include a closed rotor–stator disk cavity, a co-rotating disk cavity with radial outflow and a co-rotating disk cavity with axial throughflow. Unsteady Reynolds-averaged Navier–Stokes (RANS) simulations and large eddy simulations (LES) are compared with experimental data and previous direct numerical simulation and LES results. The results demonstrate Code_Saturne's capabilities for predicting flow and heat transfer inside rotating disk cavities. The Boussinesq approximation was implemented for modeling centrifugally buoyant flow and heat transfer in the rotating cavity with axial throughflow. This is validated using recent experimental data and CFD results. Good agreement is found between LES and RANS modeling in some cases, but for the axial throughflow cases, advantages of LES compared to URANS are significant for a high Reynolds number condition. The wall-modeled large eddy simulation (WMLES) method is recommended for balancing computational accuracy and cost in engineering applications.
Plume Spreading Due to Floor Conditions of a Plunging Liquid Jet Using Stereographic Backlit Imaging
Authors: Pillers Roy A. , Heindel Theodore J.
Published: November 2023

Plunging liquid jets are a multiphase flow studied to understand how gas is entrained in a liquid and the resulting mixing capabilities. From existing literature, it has been hypothesized that rising bubbles play a noticeable role in the multiphase hydrodynamics of the plunging liquid jet bubble plume and that separating the rising bubbles from the incoming liquid jet can result in a significant increase in the depth of the bubble plume. This study explores the effects of separating the incoming liquid jet from the rising bubble plume through floor interactions and compression effects due to a finite tank depth. This configuration is found in many natural and industrial systems, but not within published literature. Using existing theoretical models of infinite depth plunging liquid jet systems, which align reasonably well with captured baseline data, two models are developed for when floor interactions are present, one theoretical and one empirical. The models show a correlation between plume spread and floor interaction with the incoming plunging liquid jet bubble plume. Data acquired through stereographic backlit imaging over a range of flow rates show a reasonable agreement with the proposed models.
Effect of Perforation on Vortex Characteristics of a Microvortex Generator Mounted on a Flat Plate
Authors: Khare Abhishek , Khurana Shashank
Published: November 2023

The effects of perforation on the characteristics of the downstream vortex of a microvortex generator (MVG) mounted on a flat plate, are numerically investigated in this paper. A single rectangular MVG with circular and square perforation, at different locations on the MVG, is mounted on a flat plate at 16 deg installation angle with respect to the flow direction. The MVG is placed inside a turbulent boundary layer at Reynolds number of 16,293 based on MVG height and freestream velocity. The analysis is conducted using the Reynolds-averaged Navier–Stokes (RANS) modeling. The results of the analysis show that the MVG vortex is most effective when the perforation is located at the center and lower side of the MVG. The vortex strength for MVG with this perforated location is found to be much higher than the MVG without any perforation.
Artificial Intelligence-Enabled Crack Length Estimation From Acoustic Emission Signal Signatures
Authors: Ennis Shane , Giurgiutiu Victor
Published: November 2023

This article addresses the classification of fatigue crack length using artificial intelligence (AI) applied to acoustic emission (AE) signals. The AE signals were collected during fatigue testing of two specimen types. One specimen type had a 1-mm hole for crack initiation. The other specimen type had a 150-µm wide slit of various lengths. Fatigue testing was performed under stress intensity factor control to moderate crack advancement. The slit specimen produced AE signals only from crack advancement at the slit tips, whereas the 1-mm hole specimens produced AE signals from both crack tip advancement and crack rubbing or clapping. The AE signals were captured with a piezoelectric wafer active sensor (PWAS) array connected to MISTRAS instrumentation and aewin software. The collected AE signals were preprocessed using time-of-flight filtering and denoising. Choi Williams transform converted time domain AE signals into spectrograms. To apply machine learning, the spectrogram images were used as input data for the training, validation, and testing of a GoogLeNet convolutional neural network (CNN). The CNN was trained to sort the AE signals into crack length classes. CNN performance enhancements, including synthetic data generation and class balancing, were developed. A three-class example with crack lengths of (i) 10–12 mm, (ii) 12–14 mm, and (iii) 14–16 mm is provided. Our AI approach was able to classify the AE signals into these three classes with 91% accuracy, thus proving that the AE signals contain sufficient information for crack estimation using an AI-enabled approach.
Underwater Impulsive Response of a Sandwich Structure With a Multilayer Foam Core
Authors: An Zhengsong , Chen Yong , Huang Wei , Yu Lin , Deng Sihua , Liu Jiayi
Published: November 2023

The coupling between fluid–solid interaction (FSI) and structural response is a crucial factor in understanding the resistance of sandwich structures to underwater blasts. In this study, we present a theoretical model that predicts the dynamic response of multilayer foam core sandwich beams subjected to underwater impulses. We carried out a time-scale intercoupling analysis by considering the compressible core in both incident impulse and structural response. In the incident impulse coupling phase, the one-dimensional fluid–structure interaction in terms of cavitation evolution is conducted to obtain the incident pressure profile. A four inter-stages response model is proposed for further analyzing the structural response coupling phase and its coupling with core strength. Explicit finite element calculations are performed to verify the theoretical results in terms of the velocity profile, transverse deflection, and core compression. The results suggest that the interaction between the four stages of the dynamic response is significantly influenced by the impulsive intensity and core strength, and the sandwich beam does not undergo all the four stages. The equivalent core strength used in the theoretical analysis is confirmed accurate to predict the impact resistance of the corresponding graded core sandwich beam, which is inferior to the sandwich beam with uniform cores, despite having the same areal mass.
Granular Flow in Novel Octet Shape–Based Lattice Frame Material
Authors: Kaur Inderjot , Aider Youssef , Cho Heejin , Singh Prashant
Published: November 2023

Moving packed-bed heat exchangers in concentrated solar power (CSP) plants involves heat transfer between heated falling particles and supercritical carbon dioxide. The overall effective thermal conductivity of the moving packed bed and particle-side channel contact resistances are still the bottlenecks in achieving the desirable thermal transport levels. To this end, a novel moving packed bed heat exchanger consisting of an Octet lattice packed between the walls of the particle-side channel is proposed in this study. Granular flow analysis in Octet lattice moving packed bed heat exchanger (OLHX) was conducted through experiments and discrete element method (DEM)-based numerical simulations. The experimental images clearly demonstrated stagnation regions upstream of lattice fibers, void regions downstream of the fiber junctions, and wavy-type unobstructed flow on the lateral sides of the fibers. DEM simulations were successful in capturing all these critical flow phenomena. Larger flow velocities were observed on the lateral sides of the fibers in the simulations. Also, when the particles in the silo were emptied, the final images showed an accumulation of particles on the inter-fiber as well as fiber–channel wall junctions. Moreover, the fiber connections resulted in some regions devoid of particle contact on the channel endwall, which means that these regions would suffer from poor thermal exchange. The overall mass flowrate increased with increasing porosity for a fixed particle diameter.
Efficient numerical description of the dynamics of interacting multispecies quantum gases
Authors: Pichery Annie , Meister Matthias , Piest Baptist , Böhm Jonas , Rasel Ernst Maria , Charron Eric , Gaaloul Naceur
Published: November 2023

We present a highly efficient method for the numerical solution of coupled Gross–Pitaevskii equations describing the evolution dynamics of a multi-species mixture of Bose–Einstein condensates in time-dependent potentials. This method, based on a moving and expanding reference frame, compares favorably to a more standard but much more computationally expensive solution based on a frozen frame. It allows an accurate description of the long-time behavior of interacting, multi-species quantum mixtures including the challenging problem of long free expansions relevant to microgravity and space experiments. We demonstrate a successful comparison to experimental measurements of a binary Rb–K mixture recently performed with the payload of a sounding rocket experiment.
Ultrahigh density InGaN/GaN nanopyramid quantum dots for visible emissions with high quantum efficiency
Authors: Liu Cheng , Pokharel Nikhil , Lin Qinchen , Betancourt Ponce Miguel A. , Sun Jian , Lane Dominic , De Prinse Thomas J. , Tansu Nelson , Gopalan Padma , Gupta Chirag , Pasayat Shubhra S. , Mawst Luke J.
Published: November 2023

In this study, the selective area epitaxy (SAE) of InGaN/GaN nanopyramid quantum dots (QDs) on a block copolymer patterned (BCP) GaN template using metalorganic chemical vapor deposition is reported. The pattern transfer process and SAE process are developed to enable a ultrahigh density of 7–9 × 1010 cm−2 QD formation with a feature size of 20–35 nm. The growth mechanism and geometrical properties of the QDs were investigated by scanning electron microscopy and cross-sectional transmission electron microscopy, showing the nanopyramid QD structure with InGaN grown on semipolar {101¯1} planes. The optical characteristics of the nanopyramid QDs were examined by microphotoluminescence measurements. We observed QD emission centered at 488 and 514 nm, depending on the growth temperature employed. These emissions were found to be longer wavelength than those from a planar quantum well structure. This can be attributed to the combined effects of higher indium incorporation along the semipolar plane and a larger InGaN thickness. Furthermore, we also found that the QD emission intensity increases as the number of InGaN layers increases without wavelength shift, indicating a constant growth rate and indium incorporation along the semipolar plane after the formation of the nanopyramid structure. The internal quantum efficiency is estimated to be over 60% by comparing the photoluminescence (PL) intensity of QDs at low temperature and room temperature. PL emission wavelength shows an 11 nm blue shift, while the full width at half maximum decreases from 68 (351 meV) to 56 nm (303 meV) from room temperature to low temperature. By employing BCP lithography and SAE technique, we successfully demonstrated that ultrahigh density, small size InGaN/GaN nanopyramid QDs with visible emission were achieved, which could be a potential active region for QD light-emitting diodes and/or lasers.
Underwater acoustic sensing using the geometric phase
Authors: Lata Trevor D. , Deymier Pierre A. , Runge Keith , Uehara Glen S. , Hodges Todd M. W.
Published: November 2023

We present a sensing modality using the geometric phase of acoustic waves propagating in an underwater environment. We experimentally investigate the effect of scattering by a small subwavelength perturbation on a flat submerged surface. We represent the state of an acoustic field in the unperturbed and perturbed cases as multidimensional vectors. The change in geometric phase is obtained by calculating the angle between those vectors. This angle represents a rotation of the state vector of the wave due to scattering by the perturbation. We perform statistical analysis to define a signal-to-noise ratio to quantify the sensitivity of the geometric phase measurement and compare it to magnitude based measurements. This geometric phase sensing modality is shown to have higher sensitivity than the magnitude based sensing approach.
Chemokines form complex signals during inflammation and disease that can be decoded by extracellular matrix proteoglycans
Authors: Ridley Amanda J. L. , Ou Yaqing , Karlsson Richard , Pun Nabina , Birchenough Holly L. , Mulholland Iashia Z. , Birch Mary L. , MacDonald Andrew S. , Jowitt Thomas A. , Lawless Craig , Miller Rebecca L. , Dyer Douglas P.
Published: November 2023

Chemokine-driven leukocyte recruitment is a key component of the immune response and of various diseases. Therapeutically targeting the chemokine system in inflammatory disease has been unsuccessful, which has been attributed to redundancy. We investigated why chemokines instead have specific, specialized functions, as demonstrated by multiple studies. We analyzed the expression of genes encoding chemokines and their receptors across species, tissues, and diseases. This analysis revealed complex expression patterns such that genes encoding multiple chemokines that mediated recruitment of the same leukocyte type were expressed in the same context, such as the genes encoding the CXCR3 ligands CXCL9, CXCL10, and CXCL11. Through biophysical approaches, we showed that these chemokines differentially interacted with extracellular matrix glycosaminoglycans (ECM GAGs), which was enhanced by sulfation of specific GAGs. Last, in vivo approaches demonstrated that GAG binding was critical for the CXCL9-dependent recruitment of specific T cell subsets but not of others, irrespective of CXCR3 expression. Our data demonstrate that interactions with ECM GAGs regulated whether chemokines were presented on cell surfaces or remained more soluble, thereby affecting chemokine availability and ensuring specificity of chemokine action. Our findings provide a mechanistic understanding of chemokine-mediated immune cell recruitment and identify strategies to target specific chemokines during inflammatory disease.
Draft genome sequence of a highly proteolytic
Staphylococcus aureus
USA300 isolate from human urine
Authors: Jackson Jessica K. , Kennedy Sarah J. , Felton Emily A. , Cella Eleonora , Lima Amorce , Becker Deanna , Silbert Suzane , Kim Kami , Azarian Taj , Shaw Lindsey N.
Published: November 2023

The secreted proteases of
Staphylococcus aureus
have been shown to be critical during infection. Here, we present the draft genome sequence of
S. aureus
TGH337, a hyper-proteolytic USA300 strain isolated from human urine.
A group B
Streptococcus
indexed transposon mutant library to accelerate genetic research on an important perinatal pathogen
Authors: Bhavana Venkata H. , Hillebrand Gideon H. , Gopalakrishna Kathyayini P. , Rapp Rebekah A. , Ratner Adam J. , Tettelin Hervé , Hooven Thomas A.
Published: November 2023

Group B
Streptococcus
(GBS) is a major contributor to sepsis, meningitis, and pneumonia in newborns. Indexed bacterial mutant libraries accelerate pathogenesis research by allowing rapid screening of genes that contribute to disease. In this study, we created and characterized a large-scale GBS indexed library of
Himar1
mini-transposon mutant strains grown as monocultures from a mixed transposon insertion library that we had previously used for transposon-genome junction sequencing. We used a high-throughput workflow to identify transposon insertion sites in chromosomal DNA purified from individual mutants. Following quality control steps and the removal of isogenic duplicate strains, we isolated 1,919 monocultures of unique transposon insertion mutants with even dispersion across the GBS genome. Our final library, stored in barcoded, traceable glycerol stocks, contains interruptions of 878 genes and 253 intergenic regions. We also validated select library mutants with confirmatory PCR and, when possible, specific phenotypic testing. While the library contains only sparse interruptions of essential or near-essential genes, the genes represented in the set span a wide range of predicted functional categories, including roles in metabolism, structure, and virulence. In conclusion, we developed and applied a high-throughput molecular analysis and bioinformatic pipeline to generate a GBS indexed library of unprecedented scale that we believe will be a useful genetic tool for fellow GBS researchers.

IMPORTANCE

Group B
Streptococcus
(GBS) is a significant global cause of serious infections, most of which affect pregnant women, newborns, and infants. Studying GBS genetic mutant strains is a valuable approach for learning more about how these infections are caused and is a key step toward developing more effective preventative and treatment strategies. In this resource report, we describe a newly created library of defined GBS genetic mutants, containing over 1,900 genetic variants, each with a unique disruption to its chromosome. An indexed library of this scale is unprecedented in the GBS field; it includes strains with mutations in hundreds of genes whose potential functions in human disease remain unknown. We have made this resource freely available to the broader research community through deposition in a publicly funded bacterial maintenance and distribution repository.
Hyperglycemia potentiates increased
Staphylococcus aureus
virulence and resistance to growth inhibition by
Pseudomonas aeruginosa
Authors: Genito Christopher J. , Darwitz Benjamin P. , Greenwald Matthew A. , Wolfgang Matthew C. , Thurlow Lance R.
Published: November 2023

Diabetes is associated with several health consequences, including increased susceptibility to more frequent and severe infections. Bacterial infections associated with diabetes are typically polymicrobial, with
Staphylococcus aureus
and
Pseudomonas aeruginosa
frequently isolated from the same infection site.
S. aureus
and
P. aeruginosa
are frequently found in diabetic skin and soft tissue infections, in the lungs of people with cystic fibrosis, and in indwelling device infections. Numerous studies have investigated interactions between these two pathogens primarily using
in vitro
systems. These models have several limitations as they do not accurately reflect the complexities of an immune response nor the nutrient dynamics in a diabetic infection microenvironment. Here, we describe a novel murine indwelling device co-infection model that allows us to study the interactions between
S. aureus
and
P. aeruginosa
within the context of an immune response during both normal and diabetic infections. Our data shows that
P. aeruginosa
significantly inhibits
S. aureus
growth during co-infection in a normal mouse and that inhibition is not dependent on the
P. aeruginosa
PQS quorum sensing system. Conversely, in a diabetic co-infection,
S. aureus
overcomes inhibition by
P. aeruginosa
and this phenotype is reliant on
S. aureus
glycolysis. We also demonstrate that both organisms display increased virulence potential in a diabetic co-infection as we observe increased dissemination to peripheral tissues. This study revealed novel
in vivo
interactions between
S. aureus
and
P. aeruginosa
and advances our understanding of the complex interactions between microorganisms in polymicrobial infections in clinically relevant infection microenvironments.

IMPORTANCE

Individuals with diabetes are prone to more frequent and severe infections, with many of these infections being polymicrobial. Polymicrobial infections are frequently observed in skin infections and in individuals with cystic fibrosis, as well as in indwelling device infections. Two bacteria frequently co-isolated from infections are
Staphylococcus aureus
and
Pseudomonas aeruginosa
. Several studies have examined the interactions between these microorganisms. The majority of these studies use
in vitro
model systems that cannot accurately replicate the microenvironment of diabetic infections. We employed a novel murine indwelling device model to examine interactions between
S. aureus
and
P. aeruginosa
. Our data show that competition between these bacteria results in reduced growth in a normal infection. In a diabetic infection, we observe increased growth of both microbes and more severe infection as both bacteria invade surrounding tissues. Our results demonstrate that diabetes changes the interaction between bacteria resulting in poor infection outcomes.
Warming, acidification, and calcification feedback during the first hyperthermal of the Cenozoic—The Latest Danian Event
Authors: Harbich Margareta , Barnet James S.K. , Rae James W.B. , Kroon Dick
Published: November 2023

The Latest Danian Event (LDE; ca. 62.15 Ma) is a major double-spiked eccentricity-driven transient warming event and carbon cycle perturbation (hyperthermal) in the early Paleocene, which has received significantly less attention compared to the larger events of the late Paleocene–early Eocene. A better understanding of the nature of the LDE may broaden our understanding of hyperthermals more generally and improve our knowledge of Earth system responses to extreme climate states. We present planktic and benthic foraminiferal Mg/Ca and B/Ca records that shed new light on changes in South Atlantic temperature and carbonate chemistry during the LDE. Our planktic Mg/Ca record reveals a pulsed increase in sea-surface temperature of at least ~1.5 °C during the older carbon isotope excursion, and ~0.5 °C during the younger isotope excursion. We observe drops in planktic and benthic B/Ca, synchronous with pronounced negative excursions in benthic δ13C, which suggest a shift in the carbonate system toward more acidic, dissolved inorganic carbon–rich conditions, in both the surface and deep ocean. Conditions remained more acidic following the LDE, which we suggest may be linked to an enhanced ocean alkalinity sink due to changes in the makeup of planktic calcifiers, hinting at a novel feedback between calcifier ecology and ocean-atmosphere CO2.
Effectiveness of a group-based Diabetes Prevention Education Program (DiPEP) in a population with pre-diabetes: a cluster randomised controlled trial in Nepal
Authors: Shakya Pushpanjali , Shrestha Archana , Bajracharya Monish , Shrestha Abha , Kulseng Bård Erik , Karmacharya Biraj Man , Shrestha Smriti , Das Seema , Shrestha Ishwori Byanju , Barun Krishnaa , Shrestha Nistha , Skovlund Eva , Sen Abhijit
Published: November 2023

Background

Although several lifestyle intervention studies have been conducted in low/middle-income countries, there were no such studies in Nepal. Therefore, a group-based culturally tailored Diabetes Prevention Education Program (DiPEP) was conducted recently. The study aimed to evaluate the effect of DiPEP in glycated haemoglobin (HbA1c), weight, waist circumference, physical activity and diet among population with pre-diabetes.

Method

A two-arm cluster randomised controlled trial was conducted in 12 clusters of two urban areas in Nepal. The DiPEP was a 6 month intervention (four 1-hour weekly educational sessions and 5 months of follow-up by community health workers/volunteers (CHW/Vs)). A postintervention assessment was done after 6 months. Linear mixed model was used to estimate the mean difference in primary outcome (HbA1c) and secondary outcomes (weight, waist circumference, physical activity and diet) between intervention and control arms, adjusted for baseline measure.

Results

In intention-to-treat analysis with a total of 291 participants, the estimated mean difference in HbA1c was found to be 0.015 percentage point (95% CI −0.074 to 0.104) between the intervention arm and the control arm, while it was −0.077 (95% CI −0.152 to −0.002) among those who attended at least 3 out of 4 educational sessions. The estimated mean difference in weight (in participants who attended ≥1 educational session) was −1.6 kg (95% CI −3.1 to −0.1). A significantly lower grain consumption was found in intervention arm (−39 g/day, 95% CI −65 to −14) compared with the control arm at postintervention assessment.

Conclusion

Although compliance was affected by COVID-19, individuals who participated in ≥3 educational sessions had significant reduction in HbA1c and those who attended ≥1 educational session had significant weight reduction. Grain intake was significantly reduced among the intervention arm than the control arm. Hence, group-based lifestyle intervention programmes involving CHW/vs is recommended for diabetes prevention.

Trial registration number

NCT04074148.
Social security cuts and life expectancy: a longitudinal analysis of local authorities in England, Scotland and Wales
Authors: Seaman Rosie , Walsh David , Beatty Christina , McCartney Gerry , Dundas Ruth
Published: November 2023

Background

The UK Government’s ‘welfare reform’ programme included reductions to social security payments, phased in over the financial years 2011/2012–2015/2016. Previous studies of social security cuts and health outcomes have been restricted to analysing single UK countries or single payment types (eg, housing benefit). We examined the association between all social security cuts fully implemented by 2016 and life expectancy, for local authorities in England, Scotland and Wales.

Methods

Our unit of analysis was 201 upper tier local authorities (unitary authorities and county councils: 147 in England, 32 in Scotland, 22 in Wales). Our exposure was estimated social security loss per head of the working age population per year for each local authority, calculated against the baseline in 2010/2011. The primary outcome was annual life expectancy at birth between the calendar years 2012 and 2016 (year lagged following exposure). We used a panel regression approach with fixed effects.

Results

Social security cuts implemented by 2016 were estimated to be £475 per head of the working age population in England, £390 in Scotland and £490 in Wales since 2010/2011. During the study period, there was either no improvement or only marginal increases in national life expectancy. Social security loss and life expectancy were significantly associated: an estimated £100 decrease in social security per head of working age population was associated with a 1-month reduction in life expectancy.

Conclusions

Social security cuts, at the UK local authority level, were associated with lower life expectancy. Further research should examine causality.
O2 pulse slope correlates with stroke volume during exercise in patients with a Fontan circulation
Authors: Laohachai Karina , Cordina Rachael , D'Udekem Yves , Rice Kathryn , Weintraub Robert , Ayer Julian
Published: November 2023

Background

Peak oxygen pulse (O2pulse=oxygen consumption/heart rate) is calculated by the product of stroke volume (SV) and oxygen extraction. It has been shown to be reduced in patients with a Fontan circulation. However, in the Fontan population, it may be a poor marker of SV. We propose that the slope of the O2pulse curve may be more reflective of SV during exercise.

Methods

We analysed cardiopulmonary exercise test data in 22 subjects with a Fontan circulation (cohort A) and examined the association between peak SV during exercise (aortic flow measured on exercise cardiac MRI), and O2pulse parameters (absolute O2pulse and O2pulse slopes up to anaerobic threshold (AT) and peak exercise). In a separate Fontan cohort (cohort B, n=131), associations between clinical characteristics and O2pulse kinetics were examined.

Results

In cohort A, peak aortic flow was moderately and significantly associated with O2pulseslopePEAK(r=0.47, p=0.02). However, neither absolute O2pulseATnor O2pulsePEAKwas significantly associated with peak aortic flow. In cohort B, O2pulseslopePEAKand O2pulseslopeATwere not significantly associated with clinical parameters, apart from a weak association with forced vital capacity.

Conclusion

The slope of the O2pulse curve to peak exercise may be more reflective of peak SV in the Fontan population than a single peak O2pulse value.
Left ventricular hypertrophy: an ECG-based study of prevalence and risk factors in a multiethnic population
Authors: Taki Hina , Tuomilehto Jaakko , Zimmet Paul , Tamosiunas Abdonas , Kowlessur Sudhir , Magliano Dianna J , Shaw Jonathan E , Söderberg Stefan , Nilsson Ulf
Published: November 2023

Background

Left ventricular hypertrophy (LVH) is frequently seen in association with arterial hypertension and indicates poor prognosis. This study aimed to determine the prevalence of LVH and associated factors in a multiethnic population from Mauritius.

Methods

Population-based health surveys were performed in 2009 and 2015 and included in total 8961 individuals aged 35–75 years with recorded 12-lead ECG. LVH was defined according to three criteria: Sokolow-Lyon, Cornell voltage and Cornell product. Data were collected about health and lifestyle behaviour. Anthropometry and blood pressure were measured. Fasting levels of blood lipids and glucose were determined, oral glucose tolerance test was performed in people without glucose-lowering medications.

Results

The age-standardised prevalence of LVH was 9% (n=875) according to any of the three ECG criteria. Individuals with LVH were older, more likely to have hypertension, diabetes, known cardiovascular disease (CVD) and elevated levels of cholesterol and creatinine. Further, they were more likely to be of African descent (Creole) and have lower educational level. In a multivariable model, Creole (OR (95% CI)) (1.56 (1.33 to 1.83)), low educational level (1.49 (1.28 to 1.75)), hypertension (3.01 (2.55 to 3.56)), known CVD (1.42 (1.11 to 1.83)) and elevated creatinine (1.08 (1.03 to 1.14)) remained associated with LVH. Individuals with non-treated or uncontrolled hypertension had a higher risk for LVH (3.09 (95% CI 2.57 to 3.71) and 4.07 (95% CI 3.29 to 5.05), respectively), than individuals with well controlled hypertension or normotension.

Conclusion

LVH occurs more frequently in individuals with hypertension, as well as in individuals with African ancestry and/or low education level.
Probing the gravitational wave background from cosmic strings with the alternative LISA-TAIJI network
Authors: Wang Bo-Rui , Li Jin , Wang He
Published: November 2023

As one of the detection targets of all gravitational wave detectors today, the stochastic gravitational wave background (SGWB) provides an important means of understanding the evolution of our universe. In this paper, we explore the feasibility of detecting the SGWB generated by the loops arising throughout the cosmological evolution of the cosmic string network, using both individual space detectors (LISA and TAIJI) and joint space detectors (LISA-TAIJI). For the joint detectors, we choose three different configurations of TAIJI, namely TAIJIm, TAIJIp, and TAIJIc, to form the LISA-TAIJI networks, and we investigate their ability to detect the SGWB. By comparing the power-law sensitivity (PLS) curves of individual space detectors and joint detectors with the energy density spectrum of SGWB, we find that LISA-TAIJIc has the best sensitivity for detecting the SGWB from cosmic string loops. It thus holds promise for further constraining the tension of cosmic strings $$G\mu =O(10^{-17})$$

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GAN-AE: an anomaly detection algorithm for New Physics search in LHC data
Authors: Vaslin Louis , Barra Vincent , Donini Julien
Published: November 2023

In recent years, interest has grown in alternative strategies for the search for New Physics beyond the Standard Model. One envisaged solution lies in the development of anomaly detection algorithms based on unsupervised machine learning techniques. In this paper, we propose a new Generative Adversarial Network-based auto-encoder model that allows both anomaly detection and model-independent background modeling. This algorithm can be integrated with other model-independent tools in a complete heavy resonance search strategy. The proposed strategy has been tested on the LHC Olympics 2020 dataset with promising results.
Energy–momentum tensor in the scalar diquark model
Authors: Amor-Quiroz Arturo , Focillon William , Lorcé Cédric , Rodini Simone
Published: November 2023

We study in detail the energy–momentum tensor of the scalar diquark model at the one-loop level using two different regularization methods. We extract the perturbative expressions for the gravitational form factors and we check explicitly that all the Poincaré sum rules are satisfied. We confirm in particular that, like in quantum electrodynamics, the symmetric energy–momentum tensor is finite. Finally, we discuss the results for the trace of the energy–momentum tensor and its relation to the mass of the system.