bluuebunny/crossref_metadata_2025 huggingface dataset:
Reassessment of the Conventional: Numerical Validation of a One-Dimensional Model for the Prediction of Volute Losses
Authors: Ceyrowsky Thomas , Hildebrandt Andre , Heinrich Martin , Schwarze Rüdiger
Published: December 2024

The flow inside the volute of a centrifugal compressor is complex and three-dimensional. The fluid follows a swirling flow pattern, and under many operating conditions, the flow quantities are highly inhomogeneous in radial and circumferential directions. Despite the complex flow physics, the common one-dimensional approach to predict losses inside a volute is simple: The kinetic energy of each velocity component at volute inlet is charged with a loss coefficient. In case of the radial velocity, it is assumed to be constant, while the loss coefficient of the tangential velocity depends on whether the flow inside the scroll is de- or accelerated. In the former case, the loss of a sudden expansion is assumed, while in the latter case, it is presumed to be zero. The loss coefficient of the conical diffuser is also assumed to be equal to that of a sudden expansion. However, considering the complex flow physics inside the volute, it is questionable how valid these assumptions are. In this work, the authors present a comprehensive assessment of these conventional 1D predictions by investigating an extensive database of computational fluid dynamics (CFD) calculations of one volute as a standalone component. The volute has been supplied with different diffuser widths, and the inlet boundary conditions have been selected to allow for separate investigation of the effects of flow angle and flow rate. The aim is to validate the 1D model against the CFD results across the volute's entire operating range. Therefore, the CFD-predicted total pressure losses within the two subcomponents of the volute (the scroll and the conical diffuser) are assigned to the respective velocity components at volute inlet, in analogy to the 1D predictions. The results show that the loss coefficient of the radial velocity varies notably across the volute's loss map, opposing the 1D assumption of a constant loss coefficient. Conversely, the loss coefficient of the tangential velocity inside the scroll agrees well with the CFD results: High matching coefficients (i.e., lower than design flowrates) lead to high loss coefficients, which decrease almost continuously toward low matching coefficients (i.e., higher than design flowrates). The losses inside the conical diffuser depend not only on the matching coefficient but also on the flow angle at volute inlet, contrary to what the 1D model assumes. The fundamental characteristics of the global loss coefficient are predicted satisfactorily by the 1D model, while it generally overpredicts losses. Additionally, the CFD results reveal that the matching coefficient that gives minimum loss coefficients varies with the flow angle, which is not accounted for by the 1D model. Therefore, it is not adequate for assessing volute matching.
Numerical Study on the Effect of Back Cavity on the Aerodynamic Behavior of a Non-Axisymmetric Casing Treatment for Transonic Axial Compressors
Authors: Simon Martin , Benoit Rodriguez
Published: December 2024

For decades, aeronautic engineers have studied the potential of Casing Treatments (CT) to improve the aerodynamic operability of tip-limited compressors. Axial Slot Casing Treatment (or ASCT) has shown very good results on modern transonic compressor. One possible variant of ASCT uses a circumferential back cavity that links the slots outside the compressor main flow path. This study does a back-to-back comparison of two CT designs that differ only by the presence or the absence of the back cavity. The influence of both CT designs on transonic rotor performances and aerodynamics is presented. CT flows are detailed and analyzed. The analysis focuses on fluid exchanges between the CT and the main flow path. This study is based on CFD simulation; CFD results are, at first, confronted with available experimental data and then analyzed. Detailed CT flow analyses show that the presence of the cavity reduces the amplitude of the velocity fluctuations and allows for a more uniform redistribution of the recirculated mass flow. The presence of the back cavity reduces significantly the flow mass transfer between the main flow and the front part of the slots (situated before the rotor leading edge), as a consequence of the action of the transient vortex developing inside. In addition, the synchronization between the rotor blade passage and the extraction cycle, by the rear part of the slots, differs when back cavity is present or not. With the back cavity, the slot tends to extract mass flow mostly when it is close to the pressure side. Without the back cavity, the extraction is performed mostly in the middle of the blade channel. Because of these differences, the back cavity reduces the influence of the CT on rotor efficiency at the cost of a reduction in its capability to improve stall margin.
Enhancement in neuromorphic NbO2 threshold switching at cryogenic temperatures
Authors: Mburu Ted , Robinson Zachary R. , Beckmann Karsten , Lamba Uday , Powell Alex , Cady Nathaniel , Sullivan M. C.
Published: December 2024

The electrical properties and performance characteristics of niobium dioxide (NbO2)-based threshold switching devices are examined at cryogenic temperatures. Substoichiometric Nb2O5 was deposited via magnetron sputtering and patterned in microscale (2×2−15×15 μm2) crossbar Au/Ru/NbOx/Pt devices and electroformed at 3–5 V to make NbO2 filaments. At cryogenic temperatures, the threshold voltage (Vth) increased by more than a factor of 3. The hold voltage (Vh) was significantly lower than the threshold voltage for fast voltage sweeps (200 ms per measurement). If the sample is allowed to cool between voltage measurements, the hold voltage increases, but never reaches the threshold voltage, indicating the presence of nonvolatile Nb2O5 in the filament. The devices have an activation energy of Ea≈1.4 eV, lower than other NbO2 devices reported. Our work shows that even nominally “bad” selector devices can be improved by reducing the leakage current and increasing the sample resistance at cryogenic temperatures.
Interfacial crack self-healing by Sporosarcina pasteurii: From medium optimization to spore encapsulation
Authors: Hou Chenxi , Wang Chu , Zheng Ling , Peng Jie , Yuan Tao , Huang Hui , Lu Xiaolin
Published: December 2024

Self-healing cement takes advantage of microbial induced carbonate precipitation (MICP), a meritorious biological process, to achieve automatic healing of cement cracks. In this study, two beneficial factors, optimization of the bacteria culture medium and encapsulation of bacterial spores, were used to improve the MICP efficiency of Sporosarcina pasteurii in self-healing cement. On the one hand, in medium optimization, we compared the growth of Sporosarcina pasteurii fed with two generally used nitrogen sources, e.g., urea and ammonium chloride, and found that ammonium chloride can promote biomineralization more efficiently than urea. It was also confirmed that nickel (0.1 mg/l) and manganese ions (10 mg/l) benefit the MICP process through enhancement of urease activity and promotion of spore production. On the other hand, spores encapsulated in sodium alginate-gelatin gel beads prepared by using a flow nozzle device can have excellent swelling performance triggered by water. As an application demonstration, self-healing of cement cracks with consideration of the above beneficial factors was successfully verified without substantial influence on the cement compressive strength.
Efficient
in vitro
assay for evaluating drug efficacy and synergy against emerging SARS-CoV-2 strains
Authors: Woodall Maximillian , Ellis Samuel , Zhang Shengyuan , Kembou-Ringert Japhette , Kite Kerry-Anne , Buggiotti Laura , Jacobs Amy I. , Agyeman Akosua Adom , Masonou Tereza , Palor Machaela , McHugh Timothy D. , Breuer Judith , Standing Joseph F. , Smith Claire M.
Published: December 2024

Novel and repurposed antiviral drugs are available for the treatment of coronavirus disease 2019 (COVID-19). However, antiviral combinations may be more potent and lead to faster viral clearance, but the methods for screening antiviral combinations against respiratory viruses are not well established and labor-intensive. Here, we describe a time-efficient (72–96 h) and simple
in vitro
drug-sensitivity assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using standard 96-well plates. We employ different synergy models (zero interaction potency, highest single agent, Loewe, Bliss) to determine the efficacy of antiviral therapies and synergistic combinations against ancestral and emerging clinical SARS-CoV-2 strains. We found that monotherapy of remdesivir, nirmatrelvir, and active metabolite of molnupiravir (EIDD-1931) demonstrated baseline EC50s within clinically achievable levels of 4.34 mg/L (CI: 3.74–4.94 mg/L), 1.25 mg/L (CI: 1.10–1.45 mg/L), and 0.25 mg/L (CI: 0.20–0.30 mg/L), respectively, against the ancestral SARS-CoV-2 strain. However, their efficacy varied against newer Omicron variants BA.1.1.15 and BA.2, particularly with the protease inhibitor nirmatrelvir. We also found that remdesivir and nirmatrelvir have a consistent, strong synergistic effect (Bliss synergy score >10) at clinically relevant drug concentrations (nirmatrelvir 0.25–1 mg/L with remdesivir 1–4 mg/L) across all SARS-CoV-2 strains tested. This method offers a practical tool that streamlines the identification of effective combination therapies and the detection of antiviral resistance. Our findings support the use of antiviral drug combinations targeting multiple viral components to enhance COVID-19 treatment efficacy, particularly in the context of emerging viral strains.
The phospho-ferrozine assay: a tool to study bacterial redox-active metabolites produced at the plant root
Authors: Giacalone David , Schutt Emilly , McRose Darcy L.
Published: December 2024

Soil microbial communities are pivotal to plant health and nutrient acquisition. It is becoming increasingly clear that many interactions, both among and between microbes and plants, are governed by small bioactive molecules or “secondary metabolites” that can aid in communication, competition, and nutrient uptake. Yet, secondary metabolite biogeography – who makes what, where, and why—is in its infancy. Further, secondary metabolite biosynthesis genes are often silent or weakly expressed under standard laboratory conditions, making it incredibly difficult to study these small molecules. To begin to address these dual challenges, we focused on redox-active metabolites (RAMs), a specific class of small molecules, and took advantage of recent findings that many RAMs aid in acquiring phosphorus and that their production is frequently stimulated by stress for this macronutrient. We developed a screen for RAM-producing bacteria that leverages phosphorus limitation to stimulate metabolite biosynthesis and uses a colorimetric (ferrozine) iron-reduction assay to identify redox activity. We isolated 557 root-associated bacteria from grasses collected at sites across the United States (Santa Rita Experimental Range [AZ], Konza Prairie Biological Station [KS], and Harvard Forest [MA]) and from commercial tomato plants and screened them for RAM production. We identified 128 soil isolates of at least 19 genera across Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes that produced RAMs under phosphorus stress. Our work reveals that the production of RAMs under phosphorus stress is common across diverse soil bacteria and provides an approach to screen for these small molecules rapidly.

IMPORTANCE

By secreting secondary metabolites, bacteria at the plant root can defend against diseases and help acquire essential nutrients. However, the genes that synthesize secondary metabolites are typically inactive or are weakly expressed under standard laboratory conditions. This fact makes it difficult to study these small molecules and hinders the discovery of novel small molecules that may play crucial roles in agricultural and biomedical settings. Here, we focus on redox-active metabolites (RAMs), a class of secondary metabolites that can help bacteria solubilize phosphorus and are often produced when phosphorus is limited. We developed a screen that rapidly identifies RAM-producing bacteria by utilizing a colorimetric iron-reduction assay in combination with phosphorus limitation to stimulate biosynthesis. The screen reveals that RAM-producing bacteria are far more prevalent in soil than previously appreciated and that this approach can be used to identify RAM producers.
Overcoming barriers for investigating nickel-pincer nucleotide cofactor-related enzymes
Authors: Nevarez Jorge L. , Turmo Aiko , Gatreddi Santhosh , Gupta Swati , Hu Jian , Hausinger Robert P.
Published: December 2024

The nickel-pincer nucleotide (NPN) cofactor is a modified pyridinium mononucleotide that tri-coordinates nickel and is crucial for the activity of certain racemases and epimerases. LarB, LarC, and LarE are responsible for NPN synthesis, with the cofactor subsequently installed into LarA homologs. Hurdles for investigating the functional properties of such proteins arise from the difficulty of obtaining the active, NPN cofactor-loaded enzymes and in assaying their diverse reactivities. Here, we show that when the
Lactiplantibacillus plantarum lar
genes are cloned into the Duet expression system and cultured in
Escherichia coli
, they confer lactate racemase activity to the cells. By replacing
L. plantarum larA
with related genes from other microorganisms, this system allows for the generation of active LarA homologs. Furthermore, the Duet system enables the functional testing of LarB, LarC, and LarE homologs from other microorganisms. In addition to applying the Duet expression system for synthesis of active, NPN cofactor-containing enzymes in
E. coli
, we demonstrate that circular dichroism spectroscopy provides a broadly applicable means of assaying these enzymes. By selecting a wavelength of high molar ellipticity and low absorbance for a given 2-hydroxy acid substrate enantiomer, the conversion of one enantiomer/epimer into the other can be monitored for LarA homologs without the need for any coupling enzymes or reagents. The methods discussed here further our abilities to investigate the unique activities of Lar proteins.

IMPORTANCE

Enzymes containing the nickel-pincer nucleotide (NPN) cofactor are prevalent in a wide range of microorganisms and catalyze various critical biochemical reactions, yet they remain underexplored due, in part, to limitations in current research methodologies. The two significant advancements described here, the heterologous production of active NPN-cofactor containing enzymes in
Escherichia coli
and the use of a circular dichroism-based assay to monitor enzyme activities, expand our capacity to analyze these enzymes. Such additional detailed characterization will deepen our understanding of the diverse chemistry catalyzed by the NPN cofactor and potentially uncover novel roles for this organometallic species in microbial metabolism.
Preliminary clinical performance of a Cas13a-based lateral flow assay for detecting
Neisseria gonorrhoeae
in urine specimens
Authors: Allan-Blitz Lao-Tzu , Adams Gordon , Sanders Gabriela , Shah Palak , Ramesh Krithik , Jarolimova Jana , Ard Kevin L. , Branda John A. , Klausner Jeffrey D. , Sabeti Pardis C. , Lemieux Jacob E.
Published: December 2024

Nucleic acid amplification testing (NAAT) for
N. gonorrhoeae
is unavailable in resource-limited settings. We previously developed a CRISPR-based lateral flow assay for detecting
N. gonorrhoeae
. We aimed to pair that assay with point-of-care DNA extraction, assess performance in clinical urine specimens, and optimize assay kinetics. We collected urine specimens among men presenting with urethritis enrolling in a clinical trial at the Massachusetts General Hospital Sexual Health Clinic. We assessed the quantified DNA yield of detergent-based extractions with and without heat. We selected one detergent for extracting all specimens, paired with isothermal recombinase polymerase amplification for 90 minutes and lateral flow Cas13a detection, interpreted via pixel intensity analysis. We also trained a smartphone-based machine-learning model on 1,008 images to classify lateral flow results. We used the model to interpret lateral flow results from the clinical specimens. We also tested a modified amplification chemistry with a second forward primer lacking the T7-promoter to accelerate reaction kinetics. Extraction with 0.02% Triton X resulted in an average DNA yield of 2.6 × 10
6
copies/µL (SD ± 6.7 × 10
5
). We treated 40 urine specimens (
n
= 12 positive) with 0.02% Triton X, and using quantified pixel intensity analysis, the Cas13a-based assay correctly classified all specimens (100% agreement; 95% CI 91.2%–100%). The machine-learning model correctly classified 45/45 strips in the validation data set and all 40 lateral flow strips from clinical specimens. Including the second forward primer reduced incubation time to 60 minutes. Using point-of-care DNA extraction, our Cas13a-based lateral flow
N. gonorrhoeae
assay demonstrated promising performance among clinical urine specimens.

IMPORTANCE

Using a CRISPR-based assay we previously developed for
Neisseria gonorrhoeae
detection, we developed new techniques to facilitate point-of-care use. We then demonstrated the promising performance of that assay in clinical specimens. Furthermore, we developed a smartphone-based machine learning application for assisting interpretation of lateral flow strip results. Such an assay has the potential to transform the care of sexually transmitted infections in low-resource settings where diagnostic tests are unavailable. A point-of-care pathogen-specific assay, paired with the connectivity offered by a smartphone application, can also support public health surveillance efforts in such areas.
Optimizing
in vitro
spherulation cues in the fungal pathogen
Coccidioides
Authors: Homer Christina M. , Ochoa Elena , Voorhies Mark , Sil Anita
Published: December 2024

Coccidioides
spp. are part of a group of thermally dimorphic fungal pathogens, which grow as filamentous cells (hyphae) in the soil and transform to a different morphology upon inhalation into the host. The
Coccidioides
host form, the spherule, is unique and highly undercharacterized due to both technical and biocontainment challenges. Each spherule arises from an environmental spore (arthroconidium), matures, and develops hundreds of internal endospores, which are released from the spherule upon rupture. Each endospore can then go on to form another spherule in a cycle called spherulation. One of the foremost technical challenges has been reliably growing spherules in culture without the formation of contaminating hyphae and consistently inducing endospore release from spherules. Here, we present optimization of
in vitro
spherule growth and endospore release, by closely controlling starting cell density in the culture, using freshly harvested arthroconidia, and decreasing the concentration of multiple salts in spherulation media. We developed a minimal medium to test spherule growth on various carbon and nitrogen sources. We defined a critical role for the dispersant Tamol in both early spherule formation and prevention of the accumulation of a visible film around spherules. Finally, we examined how the conditions under which arthroconidia are generated influence their transcriptome and subsequent development into spherules, demonstrating that this is an important variable to control when designing spherulation experiments. Together, our data reveal multiple strategies to optimize
in vitro
spherulation growth, enabling characterization of this virulence-relevant morphology.

IMPORTANCE

Coccidioides
spp. are thermally dimorphic fungal pathogens found in the Southwest United States, Mexico, Central America, and South America.
Coccidioides
can infect both immunocompetent and immunocompromised people and can cause a devastating disseminated infection, including meningitis, with 30% mortality despite all currently available treatments. In this work, we tackle one of the current largest technical barriers to studying the fungus
Coccidioides
: reliably growing its host form
in vitro
. Our work is impactful because we have created a set of foundational tools for the burgeoning field of
Coccidioides
pathogenesis research. We have carefully optimized conditions that allow the development of
Coccidioides in vitro
into its pathogenic form. This work will open up many lines of investigation into the molecules that underlie
Coccidioides
pathogenesis.
Systematic identification of secondary bile acid production genes in global microbiome
Authors: Yang Yuwei , Gao Wenxing , Zhu Ruixin , Tao Liwen , Chen Wanning , Zhu Xinyue , Shen Mengping , Xu Tingjun , Zhao Tingting , Zhang Xiaobai , Zhu Lixin , Jiao Na
Published: December 2024

Microbial metabolism of bile acids (BAs) is crucial for maintaining homeostasis in vertebrate hosts and environments. Although certain organisms involved in bile acid metabolism have been identified, a global, comprehensive elucidation of the microbes, metabolic enzymes, and bile acid remains incomplete. To bridge this gap, we employed hidden Markov models to systematically search in a large-scale and high-quality search library comprising 28,813 RefSeq multi-kingdom microbial complete genomes, enabling us to construct a secondary bile acid production gene catalog. This catalog greatly expanded the distribution of secondary bile acid production genes across 11 phyla, encompassing bacteria, archaea, and fungi, and extended to 14 habitats spanning hosts and environmental contexts. Furthermore, we highlighted the associations between secondary bile acids (SBAs) and gastrointestinal and hepatic disorders, including inflammatory bowel disease (IBD), colorectal cancer (CRC), and nonalcoholic fatty liver disease (NAFLD), further elucidating disease-specific alterations in secondary bile acid production genes. Additionally, we proposed the pig as a particularly suitable animal model for investigating secondary bile acid production in humans, given its closely aligned secondary bile acid production gene composition. This gene catalog provides a comprehensive and reliable foundation for future studies on microbial bile acid metabolism, offering new insights into the microbial contributions to health and disease.

IMPORTANCE

Bile acid metabolism is an important function in both host and environmental microorganisms. The existing functional annotations from single source pose limitations on cross-habitat analysis. Our construction of a systematic secondary bile acid production gene catalog encompassing numerous high-quality reference sequences propelled research on bile acid metabolism in the global microbiome, holding significance for the concept of One Health. We further highlighted the potential of the microbiota-secondary bile acid axis as a target for the treatment of hepatic and intestinal diseases, as well as the varying feasibility of using animal models for studying human bile acid metabolism. This gene catalog offers a solid groundwork for investigating microbial bile acid metabolism across different compartments, including humans, animals, plants, and environments, shedding light on the contributions of microorganisms to One Health.
In vivo
interspecies dissemination of IncM2-type
bla
NDM-1
carrying plasmid
Authors: Lurie-Weinberger Mor N. , Bychenko-Banyas Darya , Mor Meirav , Laviad-Shitrit Sivan , Kaplan Ella , Rakovitsky Nadya , Keren-Paz Alona , Ben-Zvi Chaim , Carmeli Yehuda
Published: December 2024

The gastrointestinal tract is a unique ecological niche with a high abundance of various Enterobacterales in close proximity. This allows the exchange of mobile genetic elements that carry resistance determinants. In the hospital setting, resistant organisms are prevalent and selective antibiotic pressure is high, providing a supportive platform for interspecies dissemination of resistance. Seven New Delhi metallo-beta-lactamase(NDM) positive and one NDM-negative bacteria were sent for WGS followed by bioinformatics analysis. Here, we describe three separate cases of patients simultaneously colonized by two NDM producing-species (
Escherichia coli
and
Klebsiella pneumoniae
), in which we documented interspecies dissemination of the
bla
NDM-1
by an 87,450 bp IncM2 type multi-drug resistance plasmid (here named pNCICAN_NDM-01_21-il). This plasmid was found to be highly conjugative. Our results underline the risk of interspecies horizontal plasmid dissemination. Such events may cause the emergence of high-risk clones, as well as lead to under-recognized multi-species outbreaks.

IMPORTANCE

Conjugative, carbapenemase-carrying multidrug-resistant plasmids that can move between species of clinically relevant Enterobacterales pose a great risk to patients’ health, especially when they spread inside a medical institution. Yet, most institutions monitor bacteria according to species and are at risk of missing plasmid-driven outbreaks. Thus, this work indicates that plasmid surveillance is an important tool for infection control.
Protease shaving of
Mycobacterium tuberculosis
facilitates vaccine antigen discovery and delivery of novel cargoes to the Mtb surface
Authors: Lepe Bianca A. , Zheng Christine R. , Leddy Owen K. , Allsup Benjamin L. , Solomon Sydney L. , Bryson Bryan D.
Published: December 2024

Tuberculosis (TB) is the leading cause of infectious disease death and lacks a vaccine capable of protecting adults from pulmonary TB. The bacterial surface is a critical interface that shapes host-pathogen interactions. Several knowledge gaps persist in our understanding of
Mycobacterium tuberculosis
(Mtb)-host interactions that may be addressed by an improved understanding of the Mtb surface proteome, including the identification of novel vaccine targets as well as developing new approaches to interrogate host-pathogen interactions. Here, we sought to expand our understanding of the Mtb surface proteome in service of these knowledge gaps by adapting protease shaving protocols for multiplexed quantitative mass spectrometry. Pairing quantitative mass spectrometry with the construction of validation strains, we revealed several novel Mtb proteins on the Mtb surface largely derived from the PE/PPE class of Mtb proteins, including PPE18, a component of a leading Mtb vaccine candidate. We next exploited the localization of PPE18 to decorate the Mtb surface with heterologous proteins. Together, these studies reveal potential novel targets for new Mtb vaccines as well as facilitate new approaches to study difficult-to-study cellular compartments during bacterial growth and infection.

IMPORTANCE

The surface of a bacterial pathogen is a critical interface between the bacterium and the immune system. A better understanding of this interface would facilitate the discovery of new vaccine targets, new virulence proteins, and enable new technologies that modify the bacterial surface. In this study, we established a multiplexed and quantitative biochemical strategy to study the surface of
Mycobacterium tuberculosis
(Mtb) and identified new vaccine targets. We furthermore established design rules for new technologies aimed at modifying the composition of the bacterial surface. Specifically, we achieved a biological milestone that has not been rigorously reported previously, which is the successful modification of the Mtb surface with a non-native protein.
Identification of a novel MAG gene mutation with 22q11.21 microduplication linked to hereditary spastic paraplegia
Authors: Kavishwar Madhura , Bisen Pratima , Baheti Sumeet , Wade Poonam
Published: December 2024

Diagnosing hereditary spastic paraplegia (HSP) in paediatric patients can be challenging, especially when there is no positive family history. Children are often initially misdiagnosed with cerebral palsy due to the gradual progression of the disease and non-specific neuroimaging findings, despite the absence of perinatal insult. This misdiagnosis can prevent timely prenatal diagnosis, limiting the ability to make informed decisions about the pregnancy and to plan early interventions. Homozygous variants in the MAG gene, encoding myelin-associated glycoprotein (MAG), have been associated with complicated forms of HSP. In this study, we identified a novel mutation suggestive of an apparently homozygous variant of the MAG gene with deletion in exon 5 (c.451del (p.Ala151GlnfsTer22)) that is predicted to result in a frameshift and premature truncation of the protein 22 amino acids downstream to codon 151. This variant was of pathological significance in our patient who presented with cerebellar ataxia, nystagmus and hypotonia, gradually progressing to spastic paraplegia. Therefore, identifying these variants helps in understanding the underlying genetic factors contributing to HSP, aiding in correct diagnosis.
The impact of tobacco smoking and smoking cessation on lung cancer and stroke incidence among people with HIV on antiretroviral therapy in South Africa: a simulation modeling study
Authors: D’Couto Helen , Thielking Acadia M , Sewpaul Ronel , Levy Douglas E , Rigotti Nancy A , Chrysanthopoulou Stavroula A , Siedner Mark J , Freedberg Kenneth A , Wood Robin , Hyle Emily P , Reddy Krishna P
Published: December 2024

Introduction

With declining HIV-related mortality, over 20% of people with HIV (PWH) in South Africa are now over age 50 years, and tobacco-related non-communicable disease burden is increasing. We quantified the impact of smoking and smoking cessation on lung cancer and stroke incidence among PWH in South Africa.

Methods

Using a microsimulation model, we simulated 18 cohorts of initially virologically suppressed PWH over their lifetime, categorised by sex, initial age (35 years/45 years/55 years) and smoking status (current/former/never). Smoking status remains constant throughout the simulation; individuals with former smoking status quit at model start. PWH can disengage from HIV care and experience virological rebound. We modelled the relative risk of lung cancer for females (males) with current versus never smoking status as 16.69 (15.83), and for females (males) with former versus never smoking status as 1.99–8.80 (1.90–6.18), depending on age at cessation. Corresponding modelled relative risks of stroke were 1.79 (1.54) for current versus never smoking, and 1.00–1.29 (1.00–1.12) for former versus never smoking. We varied HIV-related and smoking-related parameters in sensitivity analyses.

Results

Modelled female (male) PWH who stop smoking at age 45 years experience 61.3% (70.9%) and 35.6% (18.6%) lower cumulative lung cancer and stroke incidence over 25 years compared with people who continue smoking. The proportion alive and lung cancer-free or alive and stroke-free over 25 years would increase by 10.4 (9.5) or 10.5 (8.5) percentage points. In sensitivity analysis, smoking and smoking cessation have a greater impact on lung cancer and stroke cumulative incidence if competing HIV-related mortality risks are lower or if PWH experience higher lung cancer and stroke risk compared with people without HIV apart from smoking.

Conclusion

Smoking cessation could substantially reduce lung cancer and stroke risk among PWH in South Africa. To reduce the rising non-communicable disease burden among PWH, smoking cessation should become part of routine care of PWH.
Clinical study of a micro-implantable pulse generator for the treatment of peripheral neuropathic pain: 3-month and 6-month results from the COMFORT-randomised controlled trial
Authors: Hatheway John , Hersel Alexander , Song Jonathan , Engle Mitchell , Gutierrez Genaro , Khemlani Vishal , Kapural Leonardo , Moore Gregory , Ajakwe Reginald , Trainor Drew , Hah Jennifer , Staats Peter S , Lynch Paul , Makous James , Heit Gary , Kottalgi Shilpa , Desai Mehul J
Published: December 2024

Background

We report the results from the first large, postmarket, multicentre, randomised controlled trial (RCT) evaluating peripheral nerve stimulation (PNS) for the treatment of chronic peripheral pain with a micro-implantable pulse generator (micro-IPG).

Methods

Subjects meeting eligibility were randomised (2:1) to either the active arm receiving PNS and conventional medical management (CMM) or the control arm receiving CMM alone. Treatments were limited to the following areas: lower back, shoulder, knee and foot/ankle.

Results

At 6 months, the active arm achieved an 88% responder rate with a 70% average reduction in pain. At the 3-month primary endpoint, the active arm achieved an 84% responder rate with an average pain reduction of 67% compared with the control arm, which achieved a 3% responder rate with an average pain reduction of 6%. Both responder rate and pain reduction in the active arm were significantly better than in the control arm (p<0.001). A majority of patient-reported outcomes also reached statistical significance. There have been no reports of pocket pain and no serious adverse device effects. 81% of subjects found the external wearable component of the PNS system to be comfortable.

Conclusions

This study successfully reached its primary endpoint—the active arm achieved a statistically significant superior responder rate as compared with the control arm at 3 months. These RCT results demonstrated that PNS, with this micro-IPG, is efficacious and safe. This ongoing study will follow subjects for 3 years, the results of which will be reported as they become available.
The effects of morning versus evening high-intensity interval exercise on the magnitude of the morning blood pressure surge
Authors: Bommarito Julian C. , Millar Philip J.
Published: December 2024

Blood pressure (BP) follows a circadian rhythm, dipping during sleep and surging in the morning. A larger morning BP surge is an independent predictor of cardiovascular events. Acute exercise can produce sustained periods of post-exercise hypotension that last up to 24 h; however, the timing of exercise (morning vs. evening) may influence this response. Whether the timing of exercise influences the morning BP surge remains unknown. The current study investigated the effects of a bout of high-intensity interval exercise (HIIE) performed in the morning versus evening on the magnitude of the morning BP surge in young healthy adults. Twenty-six young, otherwise healthy adults (23 ± 4 years; 15 females) completed a randomized crossover trial where, on different days, they completed a no exercise control visit or performed either morning (0800–1000 h) or evening (1700–1900 h) HIIE. Following each visit, ambulatory BP was assessed in 30 min intervals for 24 hrs. HIIE at either time did not alter the magnitude of the morning BP surge compared to control values (control: 22 ± 5 mmHg; morning exercise: 20 ± 8 mmHg; evening exercise: 22 ± 10 mmHg, P = 0.40) or when grouped separately by sex (visit × sex P = 0.42). A positive correlation existed between Morningness-Eveningness Questionnaire score and the change in nighttime BP following both exercise times (both r = 0.42 and P = 0.04). These findings suggest that HIIE does not attenuate the morning BP surge in young healthy adults and that chronotype can predict nighttime BP responses following HIIE, irrespective of exercise time of day. This study was registered on ClinicalTrials.gov (NCT06702930).
Lifetime carryover of early partial migration behaviors in an estuarine-dependent fish under climate change
Authors: Arai Kohma , Best Jessica E. , Lyubchich Vyacheslav , Miller Nathaniel R. , Secor David H.
Published: December 2024

Spatial structure within populations promotes population stability and resilience through asynchronous responses among population subcomponents (i.e., portfolio effect). In fishes, spatial structure frequently develops via early-life partial migration, leading to diversified nursery use. However, the portfolio effect depends on how adult recruitment from different nurseries exhibits asynchronous dynamics in response to climate variables, and whether nursery experiences carry over to adult demographics. For a three-decade span, we tested adult nursery recruitment and carryover effects associated with early-life partial migration in Hudson River striped bass. Early-life partial migration led to structured utilization of freshwater, brackish, and coastal nurseries, all of which recruited to the adult population. Adult recruitment from brackish nurseries increased with freshwater flow, while coastal nurseries produced more adults during severe winter years. First-year nursery experiences carried over to influence adult sex, but not growth. Most adult females utilized brackish nurseries in their first year, while adult males recruited from freshwater and brackish nurseries. Early-life partial migration led to diversified nursery use and influenced adult demographics, which buffered populations against perturbations.
The Biology of Canadian Weeds: 160. Poa pratensis L.
Authors: Holden E.M. , Grenke J.S.J. , Holden K. , Murillo R.d.A. , Villasor C. , Wagner V.
Published: December 2024

Kentucky bluegrass ( Poa pratensis L.) is a perennial, cool-season grass that is widespread across all provinces and territories and first mentioned as an invasive species in 1879. It is represented in Canada by six subspecies, three of which are native, two introduced, and one native and introduced. As a group, the subspecies are found across a wide range of habitat types, including prairie grasslands, woodlands, tundra, and disturbed sites. The introduced subspecies have been intensively used in forage and turf breeding and production. The most invasive subspecies, Poa pratensis ssp. angustifolia, is native to temperate Eurasia and was introduced to North America as a forage and cover crop. Invasions by Kentucky bluegrass result in fewer and less abundant native grass and forb species, reducing plant diversity in native prairie grasslands, and creating cascading negative effects on the ecosystem goods and services provided by these systems. Rhizomatous growth and its ability to reproduce asexually through aposporous apomixis likely enhance Kentucky bluegrass invasiveness. It is effectively controlled using glyphosate herbicide. Early-season prescribed burns are also emerging as a potential management strategy. Despite its detrimental impacts on grassland diversity, Kentucky bluegrass remains a valuable turf and forage grass in all Canadian provinces and territories.
Rh2MnGa full Heusler alloy: Unravelled physical properties and strain-induced magnetic moment using DFT
Authors: Badaoui Abdelhamid , Menni Younes , Hanoon Falah H. , Bayram Mustafa , Ikumapayi Omolayo M.
Published: December 2024

In this work, we will investigate structural, electronic, magnetic, and thermodynamic properties using density functional theory (DFT) and the quasi-harmonic Debye model. We consider ferromagnetic (FM) and non-magnetic (NM) states for L21 and Hg2CuTi-type crystal structures. The best stability is obtained for ferromagnetic Rh2MnGa in a Cu2MnAl structure with a lattice parameter of 6.07 Å and a total magnetic moment of 4.11[Formula: see text] [Formula: see text]. The compressive strain range from [Formula: see text]% to [Formula: see text]% tensile strain maintains the ferromagnetic nature and enhances the magnetic moment up to 4.39[Formula: see text] [Formula: see text]. The formation energy confirms the inherent stability of Rh2MnGa. Other important thermodynamic parameters such as the expansion coefficient ([Formula: see text]), heat capacity ([Formula: see text]), Debye temperature ([Formula: see text]) and Grüneisen constant ([Formula: see text]) are also estimated in this work.
Effect of surface conversion on thermodynamic properties of bulk aluminum oxide (Al2O3) at high pressure and temperature: First principle study
Authors: Ali Shabir , Wang Xinhua , Rasool Ghulam , Ali Amjad , Ali Rawaid , Alibrahim Khuloud A. , Alodhayb Abdullah N. , Rauf Sajid
Published: December 2024

Aluminum oxide (Al2O3) is a widely used ceramic material known for its high-temperature stability, which makes it valuable in a variety of industrial applications. The conversion from bulk to surface modification may lead to substantial changes in their thermodynamic properties. Consequently, this study endeavors to resolve the primary thermodynamic properties of Al2O3 by employing DFT calculation. The FP-LAPW+lo method is first used in the WIEN2K software to determine the surface of bulk Al2O3 with varying thicknesses. The thermodynamic parameters of Al2O3 at high pressure and elevated temperature, such as bulk modulus, thermal expansion coefficient, heat capacity, entropy, enthalpy and Debye temperature are investigated with the help of the quasi-harmonic Debye model in the Gibbs2 package. The calculated thermodynamic parameters of the Al2O3 agree with earlier findings. The results reveal that with increasing thickness, the thermal expansion coefficient and entropy decrease while the enthalpy increases, indicating that Al2O3 can be a suitable candidate for various energy and electronic industrial applications.
Uncovering accessible narration underpinning adaption of literary novels based on character network
Authors: Lei Bowen , Wu Zikai , Yang Huijie
Published: December 2024

A narrative is a co-operative result of multiple factors such as the behaviors for audiences and makers and the circumstances, storing subsequently rich information on relevant facts. In this work, we are interested in the influence of age on the characteristics of a narrative. As a case study, the original, the youth and the children’s versions for the famous novel entitled “Don Quixote” are compared. We extract the static character networks from the whole novels, and the temporal networks from slices of the whole novels. The topological properties such as the degree distribution and the clustering coefficients are adopted to represent their structural behaviors. It is found that the character networks for the original and youth versions have simultaneously scale-free, small-world and rich-club behaviors, being similar with that for social networks in reality. Compared with the character network for the original version, the structures of the character networks for the youth and children’s versions are simpler, evolve less dramatically, are composed of less number of communities. What is more, the status of main protagonists in these two adapted versions evolves less dramatically.
Persistence of charmed hadrons in QGP from lattice QCD
Authors: Sharma Sipaz
Published: December 2024

We study the nature of charm degrees of freedom near the chiral crossover based on lattice QCD calculations of the second and fourth-order cumulants of charm fluctuations, and their correlations with net baryon number, electric charge, and strangeness fluctuations. We show that below the chiral crossover temperature, [Formula: see text], the thermodynamics of charm can be very well understood in terms of charmed hadrons. We present evidence that above [Formula: see text], however, charm quark-like excitations emerge as new degrees of freedom contributing to the partial charm pressure. Nonetheless, up to temperatures as high as 175[Formula: see text]MeV, charmed hadron-like excitations significantly contribute to the partial charm pressure.
An Efficient Large Neighborhood Search Algorithm for Multi-level Constellation Scheduling Problem
Authors: Wang Shunwang , Sun Ming , Mao Xinyu , Zhou Yi
Published: December 2024

In this paper, we investigate the multilevel constellation scheduling problem (MLCSP). The MLCSP asks for scheduling time intervals within three different agents, the user satellite, the control satellites, and the ground station. Specifically, the user satellites transfer data to the control satellites, the control satellites then transmit it to the ground stations, and the objective is to schedule all the time intervals so that the number of completed tasks required by the user satellites is maximized. Compared with the setting of existing constellation scheduling problems, the problem is distinguished by its multiple scheduling role and multilevel architecture. Clearly, MLCSP is an important optimization problem in large-scale heterogeneous constellation scheduling. To solve this problem, we build both integer linear programming and constraint programming models to obtain the exact solution to MLCSP. Due to the computation limitation of exact approaches in the real-world environment, we further propose a large neighborhood search algorithm (LNSA) to practically solve the problem. Our experimental results indicate that our algorithms are very effective in benchmarks. Specifically, the LNSA can also obtain optimal solutions for large instances in practice.
Electromagnetic–gravitational perturbations of Kerr–Newman black hole
Authors: Giorgi Elena
Published: December 2024

Black holes are important objects in our understanding of the universe, as they represent the extreme nature of General Relativity. The Kerr–Newman black hole is the most general asymptotically flat black hole solution and its stability properties have long been elusive due to the interaction between gravitational and electromagnetic radiations. We illustrate the main conjectures regarding the stability problem of known black hole solutions and present some recent theorems regarding the evolution of the Kerr–Newman black holes to coupled perturbations.
Current status of DECIGO and B-DECIGO
Authors: Komori Kentaro ,   DECIGO Collaboration
Published: December 2024

We present recent advancements in the Japanese space-based gravitational-wave detectors DECIGO (Deci-Hertz Gravitational-wave Observatory) and B-DECIGO, focusing on refined sensitivity estimation, binary black hole localization with B-DECIGO and DECIGO’s capability to measure the early universe’s reheating temperature. Through simulations and experiments involving back-linked interferometers, pre-stabilized lasers and optimized satellite orbits, we demonstrate key techniques that improve signal-to-noise ratios across a broad frequency range. Our work incorporates advanced parameter adjustments, including mirror geometry optimization and noise reduction techniques such as square completion and optical springs, leading to enhanced signal-to-noise ratios over a wide frequency range. These developments pave the way for B-DECIGO and DECIGO to explore high-redshift cosmology and early universe phenomena.
Black holes in alternative gravity theories
Authors: Kunz Jutta , Blázquez-Salcedo Jose Luis , Khoo Fech Scen , Kleihaus Burkhard
Published: December 2024

In our quest toward a theory of gravity beyond General Relativity, black holes with their strong gravitational fields represent an important testing ground. Among the numerous alternative theories of gravity, much work in recent years has focused on a set of scalar–tensor theories, where the scalar field couples to higher curvature terms. The properties of the resulting black holes in such theories may differ distinctly from those of the Schwarzschild and Kerr black holes as, for instance, revealed by their shadows or their gravitational wave spectra.
Progress in the development of space inertial sensor for TianQin project
Authors: Liu Yanchong , Zhou Zebing
Published: December 2024

The TianQin project is a space gravitational wave detection program proposed by China, imposing strict requirements on inertial sensors. This paper introduces the basic principle and development progress of the TianQin project inertial sensor. At present, key technologies such as test mass, capacitance displacement sensing, and charge management have been developed, with some performance exceeding requirements. Ground-based test systems utilizing torsion pendulums have initially investigated the patch effect, magnetic field effect, residual gas damping, and temperature gradient effect. The inertial sensor is currently undergoing system integration and ground performance tests, and will be tested on TQ-2.