bluuebunny/crossref_metadata_2025 huggingface dataset:
Function and contribution of two putative
Enterococcus faecalis
glycosaminoglycan degrading enzymes to bacteremia and catheter-associated urinary tract infection
Authors: Johnson Alexandra O. , Shipman Braden M. , Hunt Benjamin C. , Learman Brian S. , Brauer Aimee L. , Zhou Serena P. , Hageman Blair Rachael , De Nisco Nicole J. , Armbruster Chelsie E.
Published: June 2024

Enterococcus faecalis
is a common cause of healthcare-acquired bloodstream infections and catheter-associated urinary tract infections (CAUTIs) in both adults and children. Treatment of
E. faecalis
infection is frequently complicated by multi-drug resistance. Based on protein homology,
E. faecalis
encodes two putative hyaluronidases, EF3023 (HylA) and EF0818 (HylB). In other Gram-positive pathogens, hyaluronidases have been shown to contribute to tissue damage and immune evasion, but the function in
E. faecalis
has yet to be explored. Here, we show that both
hylA
and
hylB
contribute to
E. faecalis
pathogenesis. In a CAUTI model, Δ
hylA
exhibited defects in bladder colonization and dissemination to the bloodstream, and Δ
hylB
exhibited a defect in kidney colonization. Furthermore, a Δ
hylA
Δ
hylB
double mutant exhibited a severe colonization defect in a model of bacteremia while the single mutants colonized to a similar level as the wild-type strain, suggesting potential functional redundancy within the bloodstream. We next examined enzymatic activity, and demonstrate that HylB is capable of digesting both hyaluronic acid (HA) and chondroitin sulfate
in vitro
, while HylA exhibits only a very modest activity against heparin. Importantly, HA degradation by HylB provided a modest increase in cell density during the stationary phase and also contributed to dampening of lipopolysaccharide-mediated NF-κB activation. Overall, these data demonstrate that glycosaminoglycan degradation is important for
E. faecalis
pathogenesis in the urinary tract and during bloodstream infection.
Bacterial isolate collection from switchgrass rhizosphere
Authors: Grady Keara L. , Shade Ashley
Published: June 2024

We provide a collection of 78 bacterial isolates from the rhizosphere of switchgrass (
Panicum virgatum L
.) at the Lux Arbor Reserve in Delton, MI, a site of the Great Lakes Bioenergy Research Center (GLBRC), Michigan State University, MI, USA. We include information on isolation conditions and full-length 16S rRNA sequences.
Phenotypic characterization of
HAM1
, a novel mating regulator of the fungal pathogen
Cryptococcus neoformans
Authors: Arsenault Yee Elizabeth , Ross Robbi L. , Santiago-Tirado Felipe H.
Published: June 2024

Cryptococcus neoformans
is a fungal pathogen responsible for >200,000 yearly cases with a mortality as high as 81%. This burden results, in part, from an incomplete understanding of its pathogenesis and ineffective antifungal treatments; hence, there is a pressing need to understand the biology and host interactions of this yeast to develop improved treatments. Protein palmitoylation is important for cryptococcal virulence, and we previously identified the substrates of its main palmitoyl transferase. One of them was encoded by the uncharacterized gene CNAG_02129. In the filamentous fungus
Neurospora crassa
, a homolog of this gene named hyphal anastomosis protein 13 plays a role in proper cellular communication and filament fusion. In
Cryptococcus
, cellular communication is essential during mating; therefore, we hypothesized that CNAG_02129, which we named hyphal anastomosis protein 1 (
HAM1
), may play a role in mating. We found that
ham1
Δ mutants produce more fusion products during mating, filament more robustly, and exhibit competitive fitness defects under mating and non-mating conditions. Additionally, we found several differences with the major virulence factor, the polysaccharide capsule, that may affect virulence, consistent with prior studies linking virulence to mating. We observed that
ham1
Δ mutants have decreased capsule attachment and transfer but exhibit higher amounts of exopolysaccharide shedding and biofilm production. Finally,
HAM1
expression is significantly lower in mating media relative to non-mating conditions, consistent with it acting as a negative regulator of mating. Understanding the connection between mating and virulence in
C. neoformans
may open new avenues of investigation into ways to improve the treatment of this disease.

IMPORTANCE

Fungal mating is a vital part of the lifecycle of the pathogenic yeast
Cryptococcus neoformans
. More than just ensuring the propagation of the species, mating allows for sexual reproduction to occur and generates genetic diversity as well as infectious propagules that can invade mammalian hosts. Despite its importance in the biology of this pathogen, we still do not know all of the major players regulating the mating process and if they are involved or impact its pathogenesis. Here, we identified a novel negative regulator of mating that also affects certain cellular characteristics known to be important for virulence. This gene, which we call
HAM1
, is widely conserved across the cryptococcal family as well as in many pathogenic fungal species. This study will open new avenues of exploration regarding the function of uncharacterized but conserved genes in a variety of pathogenic fungal species and specifically in serotype A of
C. neoformans
.
Performance evaluation of the Alinity m system for quantifying cytomegalovirus DNA in samples of the respiratory, gastrointestinal, and urinary tract
Authors: Albert Eliseo , Giménez Estela , Alberola Juan , Torres Ignacio , López Yolanda , Marcos Ana , Reinhardt Birgit , Navarro David
Published: June 2024

Quantitation of cytomegalovirus (CMV) DNA load in specimens other than blood such as bronchoalveolar lavages, intestinal biopsies, or urine has become a common practice as an ancillary tool for the diagnosis of CMV pneumonitis, intestinal disease, or congenital infection, respectively. Nevertheless, most commercially available CMV PCR platforms have not been validated for CMV DNA detection in these specimen types. In this study, a laboratory-developed test based on Alinity m CMV (“Alinity LDT”) was evaluated. Reproducibility assessment using spiked bronchial aspirate (BAS) or urine samples showed low standard deviations of 0.08 and 0.27 Log IU/mL, respectively. Evaluating the clinical performance of Alinity LDT in comparison to a laboratory-developed test based on RealTi
m
e CMV (“RealTi
m
e LDT”) showed good concordance across 200 clinical specimens including respiratory specimens, intestinal biopsies, urine, and stool. A high Pearson's correlation coefficient of r = 0.92, a low mean bias of −0.12 Log IU/mL, a good qualitative agreement of 90%, and a Cohen's kappa value of 0.76 (substantial agreement) were observed. In separate analyses of the sample types BAS, tracheal aspirates, bronchoalveolar lavage, biopsies, and urine, the assay results correlated well between the two platforms with r values between 0.88 and 0.99 and a bias <0.5 Log IU/mL. Overall, the fully automated, continuous, random access Alinity LDT yielded good reproducibility, high concordance, and good correlation to RealTi
m
e LDT in respiratory, gastrointestinal, and urine samples and may enhance patient management with rapid result reporting.

IMPORTANCE

In transplant recipients, a major cause for morbidity and mortality is end-organ disease by primary or secondary CMV infection of the respiratory or gastrointestinal tract. In addition, sensorineural hearing loss and neurodevelopmental abnormalities are frequent sequelae of congenital CMV infections in newborns. Standard of care for highly sensitive detection and quantitation of the CMV DNA load in plasma and whole blood specimens is real-time PCR testing. Beyond that, there is a need for quantitative determination of CMV DNA levels in respiratory, gastrointestinal, and urinary tract specimens using a highly automated, random access CMV PCR assay with a short turnaround time to enable early diagnosis and treatment. In the present study, clinical performance of the fully automated Alinity m analyzer in comparison to the current RealTi
m
e LDT assay was evaluated in eight different off-label sample types.
Peripartum ventricular tachycardia and PVC-induced cardiomyopathy: delivering optimal care when it’s time to deliver
Authors: Martin Gabrielle , Narvaez-Guerra Offdan , Aurigemma Gerard , Kovell Lara
Published: June 2024

Ventricular tachycardia (VT) is a rare but potentially fatal complication in pregnancy. We present a case of a pregnant woman with cardiomyopathy due to frequent premature ventricular complexes (PVCs) and VT originating from the left ventricular outflow tract. After presenting late in the third trimester, the decision was made to deliver the fetus after 4 days of medication titration due to continued sustained episodes of VT. After delivery, the patient continued to have frequent PVCs and VT several months after discharge, and she ultimately underwent a PVC ablation with dramatic reduction in PVC burden and improvement in cardiomyopathy. Multidisciplinary planning with a pregnancy heart team led to appropriate contingency planning and a successful delivery. This case highlights how multidisciplinary management is best practice in pregnancy complicated by VT and the need for better diagnostic guidelines for PVC-induced cardiomyopathy in the setting of pregnancy.
Goldenhar syndrome
Authors: Shaik Shahanaz Parveen , Arun Babu Thirunavukkarasu
Published: June 2024

Goldenhar syndrome, also recognised as oculo-auriculo-vertebral spectrum, is a very rare condition distinguished by a diverse array of clinical abnormalities affecting the ocular, auditory, vertebral and various organ systems. The pathophysiology of this condition is not fully elucidated due to its inherent genetic variability and rarity. In this report, we present a case of Goldenhar syndrome in a toddler boy, aiming to enhance the existing body of literature on this condition.
Drug-induced liver injury secondary to tamoxifen
Authors: Subhaharan Deloshaan , Murphy Grace , Commins Natalie , Azer Mary
Published: June 2024

Tamoxifen is a non-steroidal selective oestrogen receptor modulator commonly used in the treatment of breast cancer. It is associated with the development of fatty liver and steatohepatitis however drug-induced liver injury is rare. We report a woman in her 50s who developed malaise with an acute moderate aminotransferase elevation without jaundice 6 months after starting tamoxifen. She was not commenced on any other recent drugs and extensive investigation including infective and autoimmune liver screen, cross-sectional imaging and FibroScan were unremarkable. Liver biopsy revealed moderate lobular hepatitis with hepatocyte drop-out. Tamoxifen was ceased and the liver enzymes showed resolution over the following 3 months and improvement of her symptoms.
Caregiving for China’s one-child generation: a simulation study of caregiving responsibility and impact on women’s time use
Authors: Kwete Xiaoxiao , Knaul Felicia Marie , Essue Beverley M. , Touchton Michael , Arreola-Ornelas Héctor , Langer Ana , Calderon-Anyosa Renzo , Nargund Renu Sara
Published: June 2024

Introduction

The introduction, strict enforcement and recent exit of China’s one-child policy (OCP) resulted in China’s demographical changes, and, alongside its epidemiological transition, disproportionately impacted caregiving needs and demands on women. This study examines women’s caregiving responsibilities in contemporary China and evaluates how the OCP affected them.

Methods

We simulated the female population aged 25–54 years in 2020 in China and their caregiving responsibilities based on epidemiological and demographic data for women, their parents and parents-in-law, and children under 10. Three different health states were simulated for children and the senior generation: (1) healthy, (2) end of life—decedents and (3) non-decedents in need of palliative care. We combine the care responsibility for senior family members and for children using an aggregate indicator—the Care Responsibility Score (CRS) –to compare the impact of the OCP across different generations of women.

Results

Approximately 60 million working-age women are living with medium to high levels of care responsibilities (a CRS over 0.8), which is equivalent to caring for a senior family member with palliative care needs without any assistance from siblings. This includes more than one-third of the 156 million women born after the OCP and only 5% of women born before the OCP.

Conclusion

For women born under the OCP, the additional responsibility generated by a lack of siblings outweighs the benefit of having four dedicated grandparents to support them in raising children.
Reaching the unreached through building trust: a mixed-method study on COVID-19 vaccination in rural Lao PDR
Authors: Phrasisombath Ketkesone , Kubota Shogo , Elliott Elizabeth M , Horiuchi Sayaka , Ounaphom Phonepaseuth , Phimmachak Laty , Souksavanh Ounkham , Vongsouvanh Pavina , Rakotomalala Robinson Dimbintsoa , Channavong Souliya , Deharo Eric , Seal William Robert Everett , Lo Ying-Ru Jacqueline , Phoummalaysith Bounfeng
Published: June 2024

Introduction

The global COVID-19 vaccine rollout has been impacted by socioeconomic disparities and vaccine hesitancy, but few studies examine reasons for changed attitudes. In Lao People’s Democratic Republic (Lao PDR), a nationwide government-led initiative was developed in response to COVID-19, focused on community health ownership and trust in primary healthcare. The intervention team including health and governance sectors conducted capacity-building workshops with local staff and community representatives and visited villages for vaccination outreach. This study investigates the impact of this intervention on COVID-19 vaccine acceptance in rural communities.

Methods

Conducted in Xiengkhuang province, Lao PDR, from December 2022 to February 2023, the study employed a sequential mixed-methods research design. Data on vaccinated individuals from 25 villages were collected from 11 primary healthcare units; pre-post analysis was applied. Qualitative data, gathered through interviews and focus group discussions with villagers, village authorities, health staff and local government (n=102) in six villages, underwent inductive thematic analysis.

Results

First-dose vaccine uptake after the intervention increased significantly (6.9 times). Qualitative analysis identified key reasons for vaccination hesitancy: (1) mistrust due to rumours and past experiences; (2) poor communication and inconsistent messaging and (3) challenges in access for priority groups. Influencing factors during the intervention included (1) effective local-context communication; (2) leveraging existing community structures and influential individuals in a multisectoral approach and (3) increased community motivation through improved satisfaction, ownership and relationships.

Conclusion

This study highlights the impact and methods of building trust with unreached populations in health interventions, emphasising locally led solutions. Successful reversal of vaccine hesitancy was achieved by addressing root causes and fostering ownership at community and local government levels through a ‘positive approach’. This diverges from conventional supplemental immunisation activities and holds potential for systematically building trust between unreached populations and health systems. Further research could explore the impacts of routine vaccination for sustained improvements in health equity.
Development of a risk prediction score for screening for HBV, HCV and HIV among migrants in France: results from a multicentre observational study (STRADA study)
Authors: Duracinsky Martin , Yaya Issifou , Yombo-Kokule Lisa , Bessonneau Pascal , Thonon Frédérique , Rousset-Torrente Olivia , Roudot-Thoraval Françoise , Lert France , Zucman David , Chassany Olivier
Published: June 2024

Objectives

Migrants from high HIV, hepatitis B virus (HBV) or hepatitis C virus (HCV) endemicity regions have a great burden of these infections and related diseases in the host countries. This study aimed to assess the predictive capacity of the Test Rapide d'Orientation Diagnostique (TROD) Screen questionnaire for HIV, HBV and HCV infections among migrants arriving in France.

Design

An observational and multicentre study was conducted among migrants. A self-questionnaire on demographic characteristics, personal medical history and sexual behaviours was completed.

Setting

The study was conducted in the centres of the French Office for Immigration and Integration (OFII).

Participants

Convenience sampling was used to select and recruit adult migrants between January 2017 and March 2020.

Outcome measures

Participants were tested for HIV, HBV and HCV with rapid tests. For each infection, the test performance was assessed using receiver operating characteristics curves, using area under the curve (AUC) as a measure of accuracy.

Results

Among 21 133 regular migrants seen in OFII centres, 15 343 were included in the study. The participants’ mean age was 35.6 years (SD±11.1). The prevalence (95% CI) of HBV, HCV and HIV was 2.0% (1.8% to 2.2%), 0.3% (0.2% to 0.4%) and 0.3% (0.2% to 0.4%), respectively. Based on the sensitivity–specificity curve analysis, the cut-off points (95% CI) chosen for the risk score were: 2.5 (2.5 to 7.5) for HBV infection in men; 6.5 (0.5 to 6.5) for HBV infection in women; 9.5 (9.5 to 12.5) for HCV infection; and 10.5 (10.0 to 18.5) for HIV infection. Test performance was highest for HIV (AUC=82.15% (95% CI 74.54% to 87.99%)), followed by that for HBV in men (AUC=79.22%, (95% CI 76.18% to 82.26%)), for HBV in women (AUC=78.83 (95% CI 74.54% to 82.10%)) and that for HCV (AUC=75.95% (95% CI 68.58% to 83.32%)).

Conclusion

The TROD screen questionnaire showed good overall performance for predicting HIV, HBV and HCV infections among migrants in OFII centres. It could be used to optimise screening for these infections and to propose rapid screening tests to those who are at high risk.

Trial registration number

NCT02959684.
Event segmentation in ADHD: neglect of social information and deviant theta activity point to a mechanism underlying ADHD
Authors: Prochnow Astrid , Zhou Xianzhen , Ghorbani Foroogh , Roessner Veit , Hommel Bernhard , Beste Christian
Published: June 2024

Background

Attention-deficit/hyperactivity disorder (ADHD) is one of the most frequently diagnosed psychiatric conditions in children and adolescents. Although the symptoms appear to be well described, no coherent conceptual mechanistic framework integrates their occurrence and variance and the associated problems that people with ADHD face.

Aims

The current study proposes that altered event segmentation processes provide a novel mechanistic framework for understanding deficits in ADHD.

Methods

Adolescents with ADHD and neurotypically developing (NT) peers watched a short movie and were then asked to indicate the boundaries between meaningful segments of the movie. Concomitantly recorded electroencephalography (EEG) data were analysed for differences in frequency band activity and effective connectivity between brain areas.

Results

Compared with their NT peers, the ADHD group showed less dependence of their segmentation behaviour on social information, indicating that they did not consider social information to the same extent as their unaffected peers. This divergence was accompanied by differences in EEG theta band activity and a different effective connectivity network architecture at the source level. Specifically, NT adolescents primarily showed error signalling in and between the left and right fusiform gyri related to social information processing, which was not the case in the ADHD group. For the ADHD group, the inferior frontal cortex associated with attentional sampling served as a hub instead, indicating problems in the deployment of attentional control.

Conclusions

This study shows that adolescents with ADHD perceive events differently from their NT peers, in association with a different brain network architecture that reflects less adaptation to the situation and problems in attentional sampling of environmental information. The results call for a novel conceptual view of ADHD, based on event segmentation theory.
Matched-pair hybrid test paradigm for behind armor blunt trauma using an experimental animal model
Authors: Yoganandan Narayan , Shah Alok , Baisden Jamie , Stemper Brian , Otterson Mary , Somberg Lewis , Bass Cameron , Salzar Robert , McMahon Justin , Chancey Carol , McEntire Joseph
Published: June 2024

Background

The current behind armor blunt trauma (BABT) injury criterion uses a single penetration limit of 44 mm in Roma Plastilina clay and is not specific to thoracoabdominal regions. However, different regions in the human body have different injury tolerances. This manuscript presents a matched-pair hybrid test paradigm with different experimental models and candidate metrics to develop regional human injury criteria.

Methods

Live and cadaver swine were used as matched pair experimental models. An impactor simulating backface deformation profiles produced by body armor from military-relevant ballistics was used to deliver BABT loading to liver and lung regions in cadaver and live swine. Impact loading was characterized using peak accelerations and energy. For live swine, physiological parameters were monitored for 6 hours, animals were euthanized, and a detailed necropsy was done to identify injuries to skeletal structures, organs and soft tissues. A similar process was used to identify injuries to the cadaver swine for targeted thoracoabdominal regions.

Results

Two cadavers and one live swine were subjected to BABT impacts to the liver. One cadaver and one live swine were subjected to BABT impacts to the left lung. Injuries to both regions were similar at similar energies between the cadaver and live models.

Conclusions

Swine is an established animal for thoracoabdominal impact studies in automotive standards, although at lower insult levels. Similarities in BABT responses between cadaver and live swine allow for extending testing protocols to human cadavers and for the development of scaling relationships between animal and human cadavers, acting as a hybrid protocol between species and live and cadaver models. Injury tolerances and injury risk curves from live animals can be converted to human tolerances via structural scaling using these outcomes. The present experimental paradigm can be used to develop region-based BABT injury criteria, which are not currently available.
Chest trauma clinical practice guideline protects against delirium in patients with rib fractures
Authors: Kroeker Jenna , Wess Anas , Yang Yuwei , Al-Zeer Bader , Uppal Harjot , Balmes Patricia , Som Robin , Courval Valerie , Lakha Nasira , Brisson Angie , Sakai Jennifer , Garraway Naisan , Tang Raymond , Rose Peter , Joos Emilie
Published: June 2024

Introduction

Traumatic rib fractures present a considerable risk to patient well-being, contributing to morbidity and mortality in trauma patients. To address the risks associated with rib fractures, evidence-based interventions have been implemented, including effective pain management, pulmonary hygiene, and early walking. Vancouver General Hospital, a level 1 trauma center in British Columbia, Canada, developed a comprehensive multidisciplinary chest trauma clinical practice guideline (CTCPG) to optimize the management of patients with rib fractures. This prospective cohort study aimed to assess the impact of the CTCPG on pain management interventions and patient outcomes.

Methods

The study involved patients admitted between January 1, 2021 and December 31, 2021 (post-CTCPG cohort) and a historical control group admitted between November 1, 2018 and December 31, 2019 (pre-CTCPG cohort). Patient data were collected from patient charts and the British Columbia Trauma Registry, including demographics, injury characteristics, pain management interventions, and relevant outcomes.

Results

Implementation of the CTCPG resulted in an increased use of multimodal pain therapy (99.4% vs 96.1%; p=0.03) and a significant reduction in the incidence of delirium in the post-CTCPG cohort (OR 0.43, 95% CI 0.21 to 0.80, p=0.0099). There were no significant differences in hospital length of stay, ICU (intensive care unit) days, non-invasive positive pressure ventilation requirement, ventilator days, pneumonia incidence, or mortality between the two cohorts.

Discussion

Adoption of a CTCPG improved chest trauma management by enhancing pain management and reducing the incidence of delirium. Further research, including multicenter studies, is warranted to validate these findings and explore additional potential benefits of the CTCPG in the management of chest trauma patients.

Level of evidence

IIb.
A systematic review on metaheuristic approaches for autonomous path planning of unmanned aerial vehicles
Authors: Agrawal Sameer , Patle Bhumeshwar K. , Sanap Sudarshan
Published: June 2024

In the path planning of UAVs, autonomous decision-making and control are challenging tasks in the uncertain 3D environment consisting of static and dynamic obstacles. Hence, the selection of appropriate path-planning approaches is essential. In the proposed work, we have considered the meta-heuristic approaches only for an in-depth review. Metaheuristic approaches have been remarkably known for solving complex problems, optimal solutions, and lesser computational complexity compared to deterministic approaches that produce an inefficient solution. An in-depth review has been made by considering the approaches used for path planning, their advantages, disadvantages, applications, the type of time domain (offline or online), type of environment (simulation or real time), hybridization with other approaches, single or multiple UAV system, and obstacle handled (static or dynamic). It is observed that current meta-heuristic methods face constraints like inadequate convergence rates, entrapment in local optima, and complex operations, necessitating continuous development of novel approaches. Implementation of path-planning approaches are very much limited to simulation study over experimental analysis. Hybrid algorithms emerge as a potential solution for tackling these hurdles and optimizing UAV navigation, particularly in dynamic environments involving multiple UAVs. The paper highlights key research gaps, trends, along with prospects in the field of research.
Decorrelation using optimal transport
Authors: Algren Malte , Raine John Andrew , Golling Tobias
Published: June 2024

Being able to decorrelate a feature space from protected attributes is an area of active research and study in ethics, fairness, and also natural sciences. We introduce a novel decorrelation method using Convex Neural Optimal Transport Solvers (Cnots) that is able to decorrelate a continuous feature space against protected attributes with optimal transport. We demonstrate how well it performs in the context of jet classification in high energy physics, where classifier scores are desired to be decorrelated from the mass of a jet. The decorrelation achieved in binary classification approaches the levels achieved by the state-of-the-art using conditional normalising flows. When moving to multiclass outputs the optimal transport approach performs significantly better than the state-of-the-art, suggesting substantial gains at decorrelating multidimensional feature spaces.
Energy from Ellwood invariant for solutions involving $$X^0$$ variables
Authors: Ando Yuji , Suda Tomoya
Published: June 2024

For some classical solutions $$\Psi _\textrm{sol}$$

Ψ
sol

in Witten’s bosonic string field theory, it was proven that energy of the solution is proportional to the Ellwood invariant $$\textrm{Tr}(\mathcal {V}\Psi _\textrm{sol})$$

Tr
(
V

Ψ
sol

)

with $$\mathcal {V}=c\bar{c}\partial X^0\bar{\partial }X^0$$

V
=
c

c

¯

∂

X
0

∂

¯

X
0

. We examine the relation for solutions involving $$X^0$$

X
0

variables. As a result, we obtain that the relation may not hold for such solutions. Namely, there is a possibility that the energy is not proportional to the Ellwood invariant.
T-odd gluon distribution functions in a spectator model
Authors: Bacchetta Alessandro , Celiberto Francesco Giovanni , Radici Marco
Published: June 2024

We present a model calculation of T-odd transverse-momentum-dependent distributions of gluons in the nucleon. The model is based on the assumption that a nucleon contains a gluon and a remainder treated as a single on-shell spectator particle. The mass of this spectator particle is allowed to take a continuous range of values, described by a spectral function. The final-state interaction that is necessary to generate T-odd functions is modeled as the exchange of a single gluon between the spectator and the outgoing parton.
Schwarzschild black hole and redshift rapidity: a new approach towards measuring cosmic distances
Authors: Momennia Mehrab , Banerjee Pritam , Herrera-Aguilar Alfredo , Nucamendi Ulises
Published: June 2024

Motivated by recent achievements of a full general relativistic method in estimating the mass-to-distance ratio of supermassive black holes hosted at the core of active galactic nuclei, we introduce the new concept redshift rapidity in order to express the Schwarzschild black hole mass and its distance from the Earth just in terms of observational quantities. The redshift rapidity is also an observable relativistic invariant that represents the evolution of the frequency shift with respect to proper time in the Schwarzschild spacetime. We extract concise and elegant analytic formulas that allow us to disentangle mass and distance to black holes in the Schwarzschild background and estimate these parameters separately. This procedure is performed in a completely general relativistic way with the aim of improving the precision in measuring cosmic distances to astrophysical compact objects. Our exact formulas are valid on the midline and close to the line of sight, having direct astrophysical applications for megamaser systems, whereas the general relations can be employed in black hole parameter estimation studies. We also computed the frequency shift and the redshift rapidity for emitter eccentric orbits and calculated their relative error with respect to their numerical exact value for different eccentricities.
Unification of conformal gravity and internal interactions
Authors: Roumelioti Danai , Stefas Stelios , Zoupanos George
Published: June 2024

Based on the observation that the dimension of the tangent space is not necessarily equal to the dimension of the corresponding curved manifold and on the known fact that gravitational theories can be formulated in a gauge theoretic way, we discuss how to describe all known interactions in a unified manner. This is achieved by enlarging the tangent group of the four-dimensional manifold to SO(2, 16), which permits the inclusion of both gauge groups, the one that describes gravity as a gauge theory as well as the SO(10) describing the internal interactions. Moreover it permits the use of both Weyl and Majorana conditions imposed on the fermions, as to avoid the duplication of fermion multiplets of SO(10) appearing in previous attempts. The gravity theory discussed in the present work is the Conformal Gravity which, after a spontaneous symmetry breaking, can lead either to Weyl Gravity or to the usual Einstein Gravity.
Structure and properties of alumina-reinforced copper matrix composites prepared by powder metallurgy at different sintering temperatures
Authors: Hu Baisong , Wang Jiheng , Zhou Hu , Liu Hengyi
Published: June 2024

In this paper, alumina-reinforced copper-based composite materials were prepared by using the electroless plating method to coat copper powder with a layer of silver and then combining the solution sol method and powder metallurgy method. The results show that recrystallized structures and twins appear in composite materials after high-temperature sintering. As the sintering temperature increases, the ratio of recrystallized structures and twins gradually decreases, and straight coherent [Formula: see text]3 annealing twins appear in the structure, the number of high-angle grain boundaries decreased, the number of small-angle grain boundaries continues to increase, the average grain size increased from 3.89 to 4.83[Formula: see text][Formula: see text]m, the tensile strength increased from 156[Formula: see text]MPa to 167.5[Formula: see text]MPa, the maximum elongation was 9.4%, and the density increased from 6.81[Formula: see text]g/cm3 increased to 7.62[Formula: see text]g/cm3, the porosity dropped from 13.3% to 5.5%, the conductivity increased from 60.3% IACS to 73.2% IACS, the maximum hardness value was 68.71 HV, the best performance of the composite was achieved by sintering at 900°C with the tensile strength and elongation are 163[Formula: see text]MPa and 9%, respectively, the conductivity is 68.9% IACS, and the density is 7.35[Formula: see text]g/cm3. Its fracture surface shows mostly ductile features.
Research on nonlinear optical absorption coefficients of GaAs/Ga1−ηAlηAs quantum dots
Authors: Cai Yawen , Li Xuechao , Chang Ceng , Yan Xiaolong , Wang Xing
Published: June 2024

The effects of quantum dot (QD) radius, incident light intensity, temperature and other factors on the optical absorption coefficients (OACs) of cylindrical QDs are investigated numerically for typical GaAs/Ga[Formula: see text]Al[Formula: see text]As. We theoretically studied the cylindrical QDs with like-inversely quadratic Hellmann potential and parabolic potential. The expressions for the energy levels and wave functions were obtained by the Nikiforov–Uvarov method, and then the expressions for the OACs were derived by using the density matrix theory and the iterative method. Finally, the results show that the structural and external parameters affect the sensitivity of the optical absorption properties by influencing the matrix elements and energy levels, and the quantum confinement effects affect their applicable frequencies, which makes the QD system easier to tune.
PREPARATION OF HIGH QUALITY NANOCOMPOSITES OF CuO/TiO2 WITH Ar+ IONS IRRADIATION WITH ENHANCED PHOTOELECTRONIC PROPERTIES
Authors: MUNEER URFA , HONEY SHEHLA , BANO NARGIS , MAZHAR MUHAMMAD EHSAN , MEHMOOD HASSAN , MAKGOPA KATLEGO , AHMAD JAVED , ASIM JAMIL , MAAZA M. , MALIK SADIA , ARIF NADEEM
Published: June 2024

In this research work, nanocomposites of CuO/TiO2 were initially fabricated using drop casting method. Later on, these nanocomposites were irradiated for the first time by a beam of Argon ions (Ar[Formula: see text] by keeping the fluence rates of [Formula: see text] ions cm[Formula: see text], [Formula: see text] ions cm[Formula: see text], and [Formula: see text] ions cm[Formula: see text], respectively. In order to observe structural and optical properties of un-irradiated and irradiated nanocomposites, Raman Spectroscopy, Energy Dispersive X-ray (EDX), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Photoluminescence (PL) and Diffuse Reflectance Spectroscopy (DRS) analysis were performed. From Raman analysis, vibration modes confirmed the presence of different phases of TiO2 and CuO. EDX analysis clearly demonstrates the presence of Cu, Ti, and O peaks. SEM images depict agglomerated spherical nanoparticles having diameters in the range of 40–94[Formula: see text]nm. From TEM analysis, mean diameter of 56.1[Formula: see text]nm is observed for unirradiated and 33.7[Formula: see text]nm for Ar[Formula: see text] irradiated CuO/TiO2 nanoparticles in nanocomposite for fluence rates of [Formula: see text] ions cm[Formula: see text], [Formula: see text] ions cm[Formula: see text], and [Formula: see text] ions cm[Formula: see text]. HR-TEM and SAED images represent the polycrystalline nature of these nanocomposites.

Among the three peaks of PL spectra in UV–Visible region, first two peaks were observed at 356[Formula: see text]nm, and 419[Formula: see text]nm but the third peak is little shifted from 488[Formula: see text]nm with the increase in fluence rate. Values of band gap are reduced from 3.29[Formula: see text]eV to 3.17[Formula: see text]eV as the fluence rate is increased, as calculated from results of diffuse reflectance spectroscopy.
DLC FILMS ON Ti6Al4V SUBSTRATES OF NANOINDENTATION, SURFACE ROUGHNESS FOR LASER POWDER BED FUSION WAS PERFORMED UTILIZING ORTHOPEDIC IMPLANT MATERIALS
Authors: MARICHAMY M. , CHOCKALINGAM K. , ARUNACHALAM N.
Published: June 2024

Diamond-like carbon (DLC) films on titanium alloy Ti6Al4V substrates were tested with nanoindentation and surface roughness to look at the hardness and roughness of the coating and substrate systems as well as their mechanical properties. The powdered titanium alloy Ti6Al4V used in the substrate specimen was produced using laser powder bed fusion, an additive manufacturing process. In this study, we investigated the influence of substrates on the nanoindentation and surface roughness of the DLC film layer with an estimated [Formula: see text]m thickness on Ti6Al4V substrates. The findings of the nanoindentation show that the reaction to the impact was more flexible than expected. Maximum load, residual nanoindentation depth, hardness, and modulus may influence mechanical properties. The DLC-film Ti6Al4V substrate materials’ top surface roughness is measured. As a result of the increased load-carrying ability of DLC/Ti6Al4V, Ti6Al4V is a superior choice for substrate materials for DLC films, A DLC coating, measuring [Formula: see text] m in thickness, was applied to a Ti6Al4V substrate utilizing a 5-min chromium deposition process. The biocompatibility of the substrates plays a crucial role in determining the DLC films capacity to prolong the lifespan of bone implants.
Performance improvement of inverted bulk heterojunction solar cells by use of gold nanoparticles modified PEDOT: PSS as an anode buffer layer
Authors: Syarif Nur Fadhilah , Merdeka Muhammad Cikal , Hidayat Rahmat , Wulandari Priastuti
Published: June 2024

We investigate the effect of gold nanoparticles capped by Citrate (Au-CA) and 3-MPA (Au-MPA) addition into PEDOT:PSS as an anode buffer layer (ABL) in the structure of an inverted hybrid solar cell. The localized surface plasmon resonance (LSPR) excited in AuNP is expected to accelerate the transfer of holes to the anode (Ag), increasing the mobility of charge carriers in this type of solar cell. The measured UV–visible absorption spectra show typical representation of the PEDOT:PSS mixtures, which changed due to modification of Au-NP’s concentrations. The maximum absorption peak of Au-CA solution ([Formula: see text][Formula: see text]nm) is located around 522[Formula: see text]nm, while Au-MPA solution ([Formula: see text][Formula: see text]nm) is located around 528[Formula: see text]nm. These peaks are found to be red-shifted including the absorbance intensity increased when they are modified with that of PEDOT:PSS. Under the illumination of 100[Formula: see text]mW/cm2 simulated solar irradiation, the fabricated solar cell device exhibits an increase of Power Conversion Efficiency (PCE) value from 1.02% to 2.38% for the device with the addition of 20.0[Formula: see text]v/v% Au-CA and to 2.44% for the device with the addition of 2.0[Formula: see text]v/v% of Au-MPA. In our case, the enhancement of open circuit voltage ([Formula: see text]) and short circuit current density ([Formula: see text]) together occurs as a result of localized electric field effects from AuNP that influence charge transport and also the work function at the interface between PEDOT:PSS and the Ag-electrode. In our result, the fabricated solar cell with the addition of Au-MPA into the device structure shows a better performance efficiency of about 2.44% in comparison to the device with the addition of Au-CA of about 2.38%.
Scalar bosons with gravitational effects near Schwarzschild’s black hole: The Rindler recipe
Authors: Targema Terkaa Victor , Oyewumi Kayode John , Ajulo Kayode Richard , Joseph Gabriel Wirdzelii
Published: June 2024

In this study, we explore the quantum effects in the Schwarzschild spacetime for massive and massless scalar particles in the presence of an external gravitational field. The methodology involves the analytical solution of the Klein–Gordon equation for the scalar particles in the near-horizon spacetime limit, using Rindler approximation. The results show that the quantum effects differ significantly for the massive and massless cases, they possess similar characteristics near the event horizon. Bosons without mass that are distant from the event horizon undergo a reduced gravitational impact and possess a symmetric wave function that remains unchanged when they approach the event horizon. However, the symmetry is lost, indicating that the particle strives for a lower energy state and becomes erratic as it nears the event horizon. This aligns with the anticipated behavior of particles within the Schwarzschild horizon. The particles have an energy spectrum even for tremendous values of the Schwarzschild radius, which entails the validity of the Rindler approximation in the near horizon geometry. We have observed that the quantum effects of massive and massless particles differ based on the mass. Specifically, massive and massless scalars behave differently due to their geometric differences, which results in different eigenstates. Although they both tend to seek lower energy levels when they approach the event horizon, their behavior is not the same.
Applications of Marker-Assisted Gene Pyramiding in Rice Crop Improvement
Authors: Tiwari Mahima , Shrivastava Leena , Soni Urvasi , Ansari Mariyam , Dey Suddhasattya , Mondal Arijit , Asthana Nidhi
Published: June 2024

In order to give wide-ranging and long-lasting disease resistance that reduces rice output, breeding techniques are used such as the importance of selection assisted by markers and gene pyramiding. Bacterial leaf blight (BLB), which is carried on by the pathogen Xanthomonas oryzae pv. oryzae, is one such disease that significantly reduces rice yield. Numerous molecular marker techniques have already been developed because molecular markers are crucial for both marker-assisted selection and gene pyramiding. Currently, DNA-based markers, sometimes referred to as molecular markers, are the most frequently employed ones. Based on the methods used to find them, the molecular markers are divided into two main types. These markers are based on hybridization and polymerase chain reaction. The morphological (traditionally based) and biochemical (enzyme-based) markers are two more types of markers that are available. The best method for preventing rice BLB disease is host plant/varietal resistance. Gene pyramiding with the help of markers offers the potential to speed up breeding operations and ensure that the host plant’s acquired resistance will last. This research explores the use, economic significance, constraints, and potential of marker-assisted selection and gene pyramiding for rice BLB disease resistance.
Misinformation Resilient Search Rankings with Webgraph-Based Interventions
Authors: Carragher Peter , Williams Evan M. , Carley Kathleen M.
Published: June 2024

The proliferation of unreliable news domains on the internet has had wide-reaching negative impacts on society. We introduce and evaluate interventions aimed at reducing traffic to unreliable news domains from search engines while maintaining traffic to reliable domains. We build these interventions on the principles of fairness (penalize sites for what is in their control), generality (label/fact-check agnostic), targeted (increase the cost of adversarial behavior), and scalability (works at webscale). We refine our methods on small-scale webdata as a testbed and then generalize the interventions to a large-scale webgraph containing 93.9M domains and 1.6B edges. We demonstrate that our methods penalize unreliable domains far more than reliable domains in both settings and we explore multiple avenues to mitigate unintended effects on both the small-scale and large-scale webgraph experiments. These results indicate the potential of our approach to reduce the spread of misinformation and foster a more reliable online information ecosystem. This research contributes to the development of targeted strategies to enhance the trustworthiness and quality of search engine results, ultimately benefiting users, and the broader digital community.
Review—Energy and Power Requirements for Wearable Sensors
Authors: Arya Sandeep , Sharma Asha , Singh Anoop , Ahmed Aamir , Dubey Aman , Padha Bhavya , Khan Saleem , Mahadeva Rajesh , Khosla Ajit , Gupta Vinay
Published: June 2024

Wearable sensing technology has quickly transformed from a science-fiction vision to a real-life technology in various fields such as defense, medical sciences, aerospace technology, food tech, etc. Wearable devices are drawing attention in the medical field as they provide relevant information about people’s health in real-time. These sensors are flexible, cost-effective, and highly sensitive, which makes them a favorable candidate for future sensing technology. Despite being relatively small, they frequently sense, collect, and upload a variety of physiological data to enhance quality of life. This could lead to a major change in the daily life of people, but for this change to happen, sustainable energy technology that can power flexible wearable devices is needed. Wearable sensors come in a variety of shapes and sizes and require energy for their proper functioning. As a result, it is critical to develop and choose dependable energy supply systems. This review paper discusses different energy sources that are used to power wearable devices along with various challenges that are in the realm of this technology. The future holds great possibilities for wearable sensing technology, which can be explored only if the power sourcing to these devices is more sustainable, eco-friendly, and efficient.
3D Printed Carbon Nanotubes Reinforced Polydimethylsiloxane Flexible Sensors for Tactile Sensing
Authors: Jain Bhavya , Phand Krishnakant , Jain Vaibhav , Lahiri Indranil , Lahiri Debrupa
Published: June 2024

Technology is constantly evolving, and chronic health issues are on the rise. It is essential to have affordable and easy access to remote biomedical measurements. This makes flexible sensors a more attractive choice owing to their high sensitivity and flexibility along with low cost and ease of use. As an additional advantage, 3D printing has become increasingly popular in areas such as biomedicine, environment, and industry. This study demonstrates 3D-printed flexible sensors for tactile sensing. A biocompatible silicone elastomer such as polydimethylsiloxane (PDMS) with low elastic modulus and high stretchability makes an excellent wearable sensor material. Incorporating CNTs at varying concentrations (0.5, 1, 2)wt% enhances the sensor’s mechanical strength, conductivity, and responsiveness to mechanical strain. In addition to enhancing the thermal stability of the composite by 44%, multi-walled carbon nanotubes (MWCNTs) also enhanced the breaking strength by 57% with a 2 wt% CNT loading. Moreover, the contact angle values improved by 15%, making it a biomedical-grade hydrophobic surface. The electrical characteristics of these sensors reveal excellent strain sensitivity, making them perfect for monitoring finger movements and biomedical measurements. Overall, 2 wt% CNT-PDMS sensors exhibit optimal performance, paving the way for advanced tactile sensing in biomedical and industrial settings.
Students bypass the syllabus to utilize alternate LMS locations for assignment deadlines
Authors: Lopez Savannah , Pham Allison , Hsu Jeremy L. , Halpin Patricia A.
Published: June 2024

With the adoption of learning management systems (LMSs), students may no longer rely on the syllabus to locate or confirm assignment deadlines and instead rely on various LMS locations, which may not be accurate. We suggest that faculty consider taking the time to review the role and use of the syllabus on the first day of class to ensure that students know where to access current assignment deadlines to avoid confusion and missed deadlines.