bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of urbanization and parasitism on the gut microbiota of Darwin's finch nestlings
Authors: Solomon Gabrielle , Love Ashley C. , Vaziri Grace J. , Harvey Johanna , Verrett Taylor , Chernicky Kiley , Simons Shelby , Albert Lauren , Chaves Jaime A. , Knutie Sarah A.
Published: October 2023

Host‐associated microbiota can be affected by factors related to environmental change, such as urbanization and invasive species. For example, urban areas often affect food availability for animals, which can change their gut microbiota. Invasive parasites can also influence microbiota through competition or indirectly through a change in the host immune response. These interacting factors can have complex effects on host fitness, but few studies have disentangled the relationship between urbanization and parasitism on an organism's gut microbiota. To address this gap in knowledge, we investigated the effects of urbanization and parasitism by the invasive avian vampire fly (Philornis downsi) on the gut microbiota of nestling small ground finches (Geospiza fuliginosa) on San Cristóbal Island, Galápagos. We conducted a factorial study in which we experimentally manipulated parasite presence in an urban and nonurban area. Faeces were then collected from nestlings to characterize the gut microbiota (i.e. bacterial diversity and community composition). Although we did not find an interactive effect of urbanization and parasitism on the microbiota, we did find main effects of each variable. We found that urban nestlings had lower bacterial diversity and different relative abundances of taxa compared to nonurban nestlings, which could be mediated by introduction of the microbiota of the food items or changes in host physiology. Additionally, parasitized nestlings had lower bacterial richness than nonparasitized nestlings, which could be mediated by a change in the immune system. Overall, this study advances our understanding of the complex effects of anthropogenic stressors on the gut microbiota of birds.
Early‐life telomeres are influenced by environments acting at multiple temporal and spatial scales
Authors: Westneat David F. , Young Rebecca C. , Cones Alexandra G. , Kucera Aurelia C. , Anacleto Angelo , Heidinger Britt J.
Published: October 2023

An individual's telomere length early in life may reflect or contribute to key life‐history processes sensitive to environmental variation. Yet, the relative importance of genetic and environmental factors in shaping early‐life telomere length is not well understood as it requires samples collected from multiple generations with known developmental histories. We used a confirmed pedigree and conducted an animal model analysis of telomere lengths obtained from nestling house sparrows (Passer domesticus) sampled over a span of 22 years. We found significant additive genetic variation for early‐life telomere length, but it comprised a small proportion (9%) of the total biological variation. Three sources of environmental variation were important: among cohorts, among‐breeding attempts within years, and among nestmates. The magnitude of variation among breeding attempts and among nestmates also differed by cohort, suggesting that interactive effects of environmental factors across time or spatial scales were important, yet we were unable to identify the specific causes of these interactions. The mean amount of precipitation during the breeding season positively predicted telomere length, but neither weather during a given breeding attempt nor date in the breeding season contributed to an offspring's telomere length. At the level of individual nestlings, offspring sex, size and mass at 10 days of age also did not predict telomere length. Environmental effects appear especially important in shaping early‐life telomere length in some species, and more focus on how environmental factors that interact across scales may help to explain some of the variation observed among studies.
Demography‐driven and adaptive introgression in a hybrid zone of the Armeria syngameon
Authors: Villa‐Machío Irene , Heuertz Myriam , Álvarez Inés , Nieto Feliner Gonzalo
Published: October 2023

Syngameons represent networks of otherwise distinct species connected by limited gene exchange. Although most studies have focused on how species maintain their cohesiveness despite gene flow, there are additional relevant questions regarding the evolutionary dynamics of syngameons and their drivers, as well as the success of their members and the network as a whole. Using a ddRADseq approach, we analysed the genetic structure, genomic clines and demographic history of a coastal hybrid zone involving two species of the Armeria (Plumbaginaceae) syngameon in southern Spain. We inferred that a peripheral population of the sand dune‐adapted A. pungens diverged from the rest of the conspecific populations and subsequently hybridized with a locally more abundant pinewood congener, A. macrophylla. Both species display extensive plastid DNA haplotype sharing. Genomic cline analysis identified bidirectional introgression, but more outlier loci with excess A. pungens than A. macrophylla ancestry, suggesting the possibility of selection for A. pungens alleles. This is consistent with the finding that the A. pungens phenotype is selected for in open habitats, and with the strong correlation found between ancestry and phenotype. Taken together, our analyses suggest an intriguing scenario in which bidirectional introgression may, on the one hand, help to avoid reduced levels of genetic diversity due to the small size and isolated location of the A. pungens range‐edge population, thereby minimizing demographic risks of stochastic extinction. On the other hand, the data also suggest that introgression into A. macrophylla may allow individuals to grow in open, highly irradiated, deep sandy, salt‐exposed habitats.
Reproductive parameters of Bering‐Chukchi‐Beaufort Seas bowhead whales
Authors: George John C. Craig , Givens Geof H. , Horstmann Lara , Suydam Robert , Scheimreif Kayla , Stimmelmayr Raphaela , Sheffield Gay , Sformo Todd L. , Person Brian , Von Duyke Andrew , Sousa Leandra , Frantz Rita M. , Tarpley Raymond
Published: October 2023

Data from Bering‐Chukchi‐Beaufort Seas bowhead whales (Balaena mysticetus), harvested during 1973–2021 by aboriginal subsistence hunters, were used to estimate reproductive parameters: length at sexual maturity (LSM), age at sexual maturity (ASM), pregnancy rate (PR), and calving interval. Sexual maturity (N = 187 females) was determined from the presence/absence of corpora in the ovaries, or a fetus. Using sampling bias‐corrected logistic regression, LSM was estimated at 13.5 m, 95% CI [13.0, 13.8]. There was a downward trend in LSM over time, statistically significant with one method but marginal with another. A growth model translated this estimate to an ASM estimate of 23.5 years, 95% CI [20.4, 26.7]. Pregnancy rate was determined from mature females (N = 125), and from a subset limited to certain autumn‐caught whales (n = 37) to reduce bias. The PR was estimated at 0.46 globally, 95% CI [0.36, 0.55] and 0.38 for the autumn sample, 95% CI [0.20, 0.51]. Both estimated PRs are consistent with a 3‐year calving interval, because the larger estimate includes two cohorts of pregnant whales harvested in spring, and bowhead whale gestation is longer than 12 months. These analyses represent the most conclusive empirical estimates of ASM, LSM, and PR for this bowhead whale stock from the largest available data sets to date.
Language of Form, Form of Language, and the Poetic Christ
Authors: Venard Olivier‐Thomas
Published: October 2023

This essay begins with a phenomenological outline of the interchangeability of the terms ‘form’ and ‘matter’, and the transitivity of their relationship in metaphysics and aesthetics, when placed in the context of linguistic deconstruction. It then argues for an operative, rather than resultative, approach to ‘form’, pointing out that in a created cosmos created minds only ever approach substantial (metaphysical) forms by making use of language, i.e. by inventing linguistic forms. From there, the argument turns to the special language of the Scriptures, when read both in their historical relativity and as vehicles of the transcendent divine Word, and explores the analogy between the paradoxes of the matter‐form pair and several features of the Scriptures, such as the Möbius strip‐like enunciative structure, in which human and divine voices are reciprocally interwoven. Christ, the principle of the unity of the divine and human voices of the Scriptures, appears as the source of all the analogical instances of the transitivity and reversibility of form‐matter duality. Even more profoundly than his restoration of the signum, Christ re‐establishes ‘form’ in its interaction with ‘matter’.
Comparing emollient use with topical luliconazole (azole) in the maintenance of remission of chronic and recurrent dermatophytosis. An open‐label, randomized prospective active‐controlled non‐inferiority study
Authors: Pathania Yashdeep Singh , CDS Katoch , Kumar Ashok
Published: October 2023

Background

Literature on emollient use in the management of chronic and recurrent dermatophytosis is limited.

Objective

To assess the efficacy of emollient in the remission maintenance of chronic and recurrent dermatophytosis.

Methods

In this randomized open‐label study with the intention to treat, 80 patients with chronic recurrent dermatophytosis were randomized into two groups, where both groups were treated adequately for 6 weeks, followed by continuation of topical azole in group A and topical emollient in group B for 6 weeks. Clinical remission was determined by disappearance signs and symptoms of tinea lesions with or without hyperpigmentation. Physician and patient global assessment scores were evaluated every 2 weeks for 6 weeks to assess remission maintenance.

Results

A total of 80 patients of chronic and recurrent dermatophytosis were assessed for remission maintenance. The recurrence of disease occurred in 20 patients overall, wherein 7 patients (17.5%) in group A and 13 patients (32.5%) in group B at the end of the study (18 weeks); however, the difference between the two groups was not statistically significant (p = .121). The mean physician global assessment scores of group A and group B at 12 weeks were 4.45 ± 0.74 and 4.15 ± 0.92, 4.43 ± 0.90 and 4.10 ± 0.98 at 14 weeks, 4.0 ± 1.32 and 3.98 ± 1.23 at 16 weeks, 3.85 ± 1.44 and 3.90 ± 1.35 at 18 weeks, respectively. The mean patient global assessment scores of group A and group B were 4.65 ± 0.62 and 4.25 ± 0.87 at 12 weeks, 4.40 ± 0.87 and 4.17 ± 0.98 at 14 weeks, 4.18 ± 1.15 and 4.12 ± 1.30 at 16 weeks and 3.97 ± 1.33 and 3.90 ± 1.51 at 18 weeks.

Conclusion

The present study concludes that the efficacy of emollient was not inferior to topical luliconazole for maintaining remission in chronic and recurrent dermatophytosis.
Contribution to the study of inflammasome and programmed cell death in paracoccidioidomycosis oral lesions
Authors: Pagliari Carla , Kanashiro‐Galo Luciane , Sotto Mirian Nacagami
Published: October 2023

Background

Paracoccidioidomycosis is the most prevalent systemic mycosis in Latin America, with a high incidence in Brazil, Colombia and Venezuela, and constitutes a serious public health problem, a frequent cause of morbidity and disability for work. Some mechanisms of cell death are described as important tools in infectious processes. When apoptosis is blocked, RIPK (Receptor‐interacting protein kinase) 3 dependent, a caspase‐independent form of cell death, can limit the replication and spread of pathogens. Some molecules that mediate necroptosis include RIPK3 and have been extensively studied due to their signalling mechanism and pathological function. RIPK3 activates NLRP1 and NLRP3‐mediated inflammasome formation. Caspase‐1 has an important role in processing the cytokines ILβ and IL18 to their active form. Such molecules are part of the inflammasome characterization, whose caspase‐1‐dependent activation promotes the death of pyroptotic cells and the secretion of proinflammatory cytokines. Knowledge about the mechanisms of pathogen‐mediated cell death can be useful for understanding of the pathogenesis of infections and inflammatory conditions.

Objective

The objective of this work was to identify the mechanisms of programmed cell death and inflammasome components in human oral mucosal lesions of paracoccidioidomycosis through immunohistochemical methods and identification of RIPK‐3, IL1β, IL18, NLRP‐1 and caspase‐1. Thirty specimens were included, and a histopathological analysis of the lesions was performed using haematoxylin–eosin staining.

Results

Our results on in situ expression of inflammasome elements and programmed cell death showed increased expression of IL‐1β, NLRP‐1, caspase‐1 and RIPK‐3. We suggest that inflammasome complex participate in the immunopathogenesis in paracoccidioidomycosis oral lesions in an interplay with RIPK3.
Musicianship and the masteries of the stars: music and musicians in the Liber Nativitatum
Authors: Doyle Oliver
Published: October 2023

This article shines a light on the musical contents of a “book of births”, the Liber Nativitatum or Albubather, written by the Persian Astrologer Abu Bakr al‐Hassan ibn al‐Khasib in the ninth century, translated into Latin at the beginning of the thirteenth century, and published in Venice in 1501. “Books of births” served to show how an individual's fortune and personal traits could be ascertained from the position of the celestial bodies throughout the individual's gestation period. A significant portion of these traits pertain to loquacity, hearing, musical skill and the likelihood of a musical profession. Thanks to the connotations each celestial body bore – positive and negative – and the traits they are described as imparting, the Liber Nativitatum makes it possible to identify the skills and traits requisite for good musical performance, as well as those traits which might inhibit it.
The “velocity barrier” in giant slalom skiing: An experimental proof of concept
Authors: Chollet Mickael , Delhaye Clément , Samozino Pierre , Bowen Maximilien , Morel Baptiste , Monjo Florian , Hintzy Frédérique
Published: October 2023

Background

Alpine skiing involves the conversion of potential energy into kinetic energy, with the “velocity barrier” (VB) at each moment corresponding to the maximal velocity at which the athlete can ski while staying within the boundaries of the gates and maintaining control. Nevertheless, this concept has never been proven by evidence. The aim of this study was to experimentally test the existence of the VB and clarify its relationship with skier's force production/application capacities.

Methods

Fourteen skiers were equipped with ski‐mounted force plates and a positional device and ran a 2‐turn Giant Slalom section starting from eight different heights on the slope. Three conditions were selected for further analysis: minimal entrance velocity (vmin); entrance velocity allowing the better section time (VB); maximal entrance velocity (vmax). Entrance velocity, section time, mean force output, ratio of force application effectiveness, velocity normalized energy dissipation, and path length were compared between the three conditions. Moreover, skier's mechanical energy and velocity curves were compared all along the section between the three conditions using SPM analysis.

Results

The section time was reduced in VB compared to vmin (p < 0.001) and vmax (p = 0.002). Skiers presented an incapacity to increase force output beyond the VB (p = 0.441) associated with a lower force application effectiveness (p = 0.005). Maximal entrance velocity was associated to higher energy dissipation (p < 0.001) and path length (p = 0.005).

Conclusion

The present study experimentally supports the existence of the VB. The force production/application capacities seem to limit the skiing effectiveness beyond the VB, associated to increased energy dissipations and path length.
Fathers and childcare: Are gender social norms in India changing?
Authors: Motwani Ameeta
Published: October 2023

The involvement of fathers in the care of new‐borns and young children is becoming a fact of life in contemporary urban India. However, there is little empirical research on changes in the gender social norms around childcare in India. We do not know if there are some childcare responsibilities that men are happy to take on while there are others which are still considered the ‘Mommy domain’? The article is based on an exploratory research study interrogating the increasing role played by fathers in the care of their young children in urban India. Based on in‐depth interviews with two generations of fathers, it focuses on the differences in their participation in childcare activities. The study finds that both, the practice as well as the discourse concerning childcare among urban middle‐class Indians are changing and thus the gender norms for childcare responsibility can be said to be somewhat shifting for a certain class of Indian families.
Reticulate evolution of the tertiary relict Osmanthus
Authors: Li Yongfu , Li Xuan , Nie Shuai , Zhang Min , Yang Qinghua , Xu Wenbin , Duan Yifan , Wang Xianrong
Published: October 2023

When interspecific gene flow is common, species relationships are more accurately represented by a phylogenetic network than by a bifurcating tree. This study aimed to uncover the role of introgression in the evolution of Osmanthus, the only genus of the subtribe Oleinae (Oleaceae) with its distribution center in East Asia. We built species trees, detected introgression, and constructed networks using multiple kinds of sequencing data (whole genome resequencing, transcriptome sequencing, and Sanger sequencing of nrDNA) combined with concatenation and coalescence approaches. Then, based on well‐understood species relationships, historical biogeographic analyses and diversification rate estimates were employed to reveal the history of Osmanthus. Osmanthus originated in mid‐Miocene Europe and dispersed to the eastern Tibetan Plateau in the late Miocene. Thereafter, it continued to spread eastwards. Phylogenetic conflict is common within the ‘Core Osmanthus’ clade and is seen at both early and late stages of diversification, leading to hypotheses of net‐like species relationships. Incomplete lineage sorting proved ineffective in explaining phylogenetic conflicts and thus supported introgression as the main cause of conflicts. This study elucidates the diversification history of a relict genus in the subtropical regions of eastern Asia and reveals that introgression had profound effects on its evolutionary history.
Neutronic Analysis and Fuel Cycle Parameters of Transuranic-UO2 Fueled Dual Cooled VVER-1000 Assembly
Authors: Ahmed Md. Tanvir , Shelley Afroza , Hosen Md. Nobir
Published: October 2023

The feasibility of transuranic (TRU) fuel rods has been studied for a dual-cooled VVER-1000 assembly along with the conventional UO2 fuel rods. It has been found that the heterogeneous arrangements of TRU and UO2 fuel rods help to improve the multiplication factor, enhance the fuel cycle parameters, and maintain the negative Doppler coefficient of the reference VVER-1000 assembly. Within the different heterogeneous combinations of TRU and UO2 fuel rods, the equal number of UO2 and TRU fuel rods, which is referred to as model 6 increased the multiplication factor of the reference assembly by 7.66% at the beginning of the cycle. Furthermore, the fuel cycle parameter becomes almost double for this model in comparison with the reference assembly. TRU rods make the neutron spectrum of reference assembly slightly harder and increase the fast fission rate. However, the Doppler coefficient becomes less negative, and flux level decreases with increasing the number of TRU rods. By considering the safety parameters and neutronic behavior, model 6 (equal number of UO2 and TRU fuel rods) is to be effective for the annular fueled VVER-1000 reactor.
The Force–Velocity Profiling Concept for Sprint Running Is a Dead End
Authors: Ettema Gertjan
Published: October 2023

Purpose: In this commentary, I present arguments against the use of the force–velocity profiling concept in design and adaptations of training programs targeting sprinting. The purpose of this commentary is to make sports practitioners more aware of the rationale behind the concept and explain why it does not work. Rationale: Force–velocity profiling is a mathematical way to present the velocity development during sprint behavior. Some details of this behavior may be accentuated by transforming it to other variables, but it does not add any new information about sprint performance. Thus, contrary to what is often claimed, the force–velocity profile does not represent maximal capacities (ability of force and velocity generation) of the athlete. It is claimed that through force–velocity profiling one may identify the optimal ratio of force and velocity capacities. Furthermore, proponents of the force–velocity profiling concept suggest that through directed training force and velocity capacities can be altered (inversely dependent) to obtain this optimal ratio, without changing the capacity to express power. Fundamentally, this idea is unfounded and implausible. Conclusion: At best, force–velocity profiling may be able to identify between-athletes differences. However, these can be more easily deduced directly from performance time traces.
Mid-Cretaceous to early Eocene Neo-Tethyan subduction records in West Sulawesi, Indonesia
Authors: Zhang Xiaoran , Chung Sun-Lin , Tien Chia-Yu , Maulana Adi , Mawaleda Musri , Lee Hao-Yang , Liu Ping-Ping , Xi Jinyu
Published: October 2023

Situated in the heart of the Indonesian archipelago, Sulawesi records well-developed Cenozoic magmatism, yet its Cretaceous magmatic evolution remains enigmatic. Here, we report new U-Pb-Hf isotopic data of detrital zircons from West Sulawesi, Indonesia to constrain its Cretaceous to Eocene magmatic tempo. Detrital zircons aged at ca. 105−80 Ma and ca. 70−45 Ma occur as the most dominant age populations and show high positive εHf(t) values, indicating derivation from juvenile sources with limited continental crustal contamination. Our new data, combined with available results, support the existence of an Andean-type continental margin in West Sulawesi during mid-Cretaceous to early Eocene times. Importantly, the magmatic tempo of West Sulawesi is also consistent with those of southern Lhasa (Tibet) and Sumatra (Indonesia), but contrasts with those of Paleo-Pacific subduction-related arcs in SE China, SE Vietnam, East Malaysia, and NW Borneo. Therefore, we put forward that West Sulawesi may be the southeasternmost component of the Neo-Tethyan arc system that spreads over 7500 km, from southern Tibet to SE Sundaland. Such a huge arc system with concurrent magmatic flare-ups and lulls in South Asia may have played a significant role in global-scale plate reorganization.
Noncommutative scalar field theory in a curved background: Duality between noncommutative and effective commutative description
Authors: Ćirić Marija Dimitrijević , Konjik Nikola , Samsarov Andjelo
Published: October 2023

We study a noncommutative (NC) deformation of a charged scalar field, minimally coupled to a classical (commutative) Reissner–Nordström-like background. The deformation is performed via a particularly chosen Killing twist to ensure that the geometry remains undeformed (commutative). An action describing a NC scalar field minimally coupled to the RN geometry is manifestly invariant under the deformed [Formula: see text] gauge symmetry. We find the equation of motion and conclude that the same equation is obtained from the commutative theory in a modified geometrical background described by an effective metric. This correspondence we call “duality between formal and effective approach”. We also show that a NC deformation via semi-Killing twist operator cannot be rewritten in terms of an effective metric. There is dual description for those particular deformations.
CFT thermal 2-point function
Authors: Bajc Borut , Lugo Adrián
Published: October 2023

This is a short review of our recent work [B. Bajc and A. R. Lugo, arXiv:2212.13639 [hep-th]] with some new original results. We numerically calculate the conformal two point correlation function of operators with arbitrary scale dimension up to order [Formula: see text] in the low temperature expansion. We analytically compute its large scale dimension limit up to the same order.
Quasinormal modes of the (2+1)-dimensional Chern–Simons black hole via symmetry
Authors: Avramov V. , Rashkov R. C. , Vetsov T.
Published: October 2023

In this study, we adopt an algebraic method to find the spectrum of quasinormal modes for the three-dimensional regular rotating Chern–Simons black hole solution. The latter is a solution to topologically massive gravitoelectrodynamics (TMGE). Due to the fact that the Chern–Simons black hole metric admits four local Killing vectors generating the [Formula: see text] Lie algebra, the solutions to the equations of motion for the fields can be classified by the representations of this algebra. Subsequently, the quasinormal spectrum can be extracted as the infinite tower of descendants of the highest weight mode of [Formula: see text].
Some exact anisotropic cosmological solutions of a simple nonlocal de Sitter gravity
Authors: Dimitrijevic Ivan
Published: October 2023

It was shown recently that a very simple nonlocal de Sitter gravity model contains exact vacuum cosmological solution which mimics dark energy and dark matter in flat space. Some other interesting solutions have been also found. In this paper, we proceed with finding several new exact cosmological solutions which belong to Bianchi I space. These solutions are simple generalizations of solutions previously found in the FLRW case of the same nonlocal de Sitter gravity model. Obtained results are discussed.
Anisotropic stellar modeling with clouds of string and quintessence field in Rastall gravity
Authors: Ditta Allah , Tiecheng Xia , Mahmood Irfan , Asia Munaza , Mahmood Asif
Published: October 2023

This paper proposes a new framework to investigate the spherically symmetric of anisotropic stars with clouds of strings and quintessence field in Rastall gravity. We develop the field equations in a spherically symmetric space–time with a quintessence field and clouds of string. We utilize the mass and radius of Her X-1, Vela X-1, SMC X-1, SAX J1808 0.4-3658 and 4 U 1538-52, which are well mentioned in the literature. We applied the matching conditions by considering outer space calculated in Rastall gravity to evaluate the constants parameters. To check the stability and physical presence of compact models, we computed the most important features of quintessence stars in the presence of a cloud of strings. We explored characteristics including energy density, quintessence density, radial pressure, tangential pressure gradients, anisotropic factor, energy conditions, sound speeds, TOV forces, EoS components, mass function, compactification and redshift.
Balancing multiple charge particle excesses with baryon asymmetry
Authors: Beylin Vitaly A. , Khlopov Maxim Yu. , Sopin Danila O.
Published: October 2023

Stable multiple charged particles can possess electroweak charges, as per the walking technicolor models. An asymmetry of these particles is balanced by sphaleron transitions which among other things can provide an excess of baryons and/or leptons. A possibility to generate sufficient amount of particles with the charge [Formula: see text] to explain the observed dark matter density by dark atoms (which are bound states of multiple charged techniparticles with n helium nuclei) is considered in the framework of thermodynamic approach.
Is it time to rethink quantum gravity?
Authors: Oppenheim Jonathan
Published: October 2023

Although it’s widely believed that gravity should have a quantum nature like every other force, the conceptual obstacles to constructing a quantum theory of gravity compel us to explore other perspectives. Gravity is not like any other force. It alone defines a universal spacetime geometry upon which quantum fields evolve. We feel gravity because matter causes spacetime to bend. Time flows at unequal rates at different locations. The rate at which time flows, and the causal structure it provides, may be required to have a classical description in order for quantum theory to be well-formulated. I discuss arguments for this proposition, but ultimately conclude that we must turn to experiment to guide us.
AN OBSERVATIONAL STUDY TO EVALUATE FUNCTIONAL OUTCOME OF PCL BONY AVULSION FRACTURE FIXATION USING BURKS AND SCHAFFER APPROACH
Authors: Swarnkar Himanshu , Singh Abhay , Thakur Robin , Kumar Manoj , Jain Hemant , Vaishy Arun , Lohchab Ishani
Published: October 2023

Introduction: Posterior cruciate ligament (PCL) is the stronger of the two cruciate ligaments of the knee and is a constraint to posterior dislocation of the knee in 90 degrees of flexion. Damage to PCL due to bony avulsion if not treated can lead to chronic pain and patellar degeneration due to posterior subluxation of the tibia. Various modalities are there to treat PCL bony avulsion fracture, including the conservative method (in undisplaced or <5 mm displaced bony piece) and open methods, including the midline posterior approach, Burks and Schaffer approach, and Arthroscopic approach with the help of sutures and screws.

The purpose of this study was to objectively evaluate the results after Burks and Schaffer’s approach to tibial PCL avulsion fractures using cannulated cancellous (cc) screws with or without a washer.

Methodology: This is an observational study of PCL bony avulsion fractures of 30 patients in the age group of 15–45 years admitted to Dr. S.N. Medical College and Associated Group of Hospitals, Jodhpur who were followed up for six months and were classified under Modified Meyers and Mckeever classification. Patients with associated vascular injuries and severe comorbidities were excluded. Through Burks and Schaffer’s approach, PCL bony avulsion fractures were fixed with a 4 mm partially threaded cc screw with or without a washer. Their functional outcome was assessed using the Lysholm scoring system.

Results: In our study, 30 patients are treated with the Burks and Schaffer method out of which excellent surgical outcomes were found in 23 (76.67%) patients and good outcomes in seven patients (23.33%).

Conclusion: PCL bony avulsion fracture treated with screw fixation through the Burks and Schaffer approach has excellent clinical outcomes due to the ease of performing it with fewer complications during exposure and fixation with an easily available and affordable implant. With this method, patients reported stable knees with a good range of motion and functional outcomes.
CT-GUIDED PERCUTANEOUS TREPHINATION OF NIDUS IN OSTEOID OSTEOMA — A SAFE APPROACH FOR DIFFICULT TO ACCESS LESIONS
Authors: Agarwal Shubham , Jain Hemant , Sihag Prateek , Raichandani Kishore
Published: October 2023

Introduction: Osteoid osteoma is a benign painful bony lesion that often affects children and young adults. It is 3% of all bone tumors. It may result in growth disturbance, bony deformity, joint swelling and contractures. Long bones especially of the lower limb are the most commonly affected regions. During the initial period, the resection of nidus was performed by open surgery where a bone block was removed. This was followed by development of computed tomography (CT)-guided procedures for complete removal of nidus using various percutaneous techniques. These include CT-guided radiofrequency ablation (RFA) or trephination. If these lesions are near any important vascular structures, it becomes difficult to use RFA due to risk of injuring them. While the results of RFA are well studied, percutaneous trephination is still not widely researched.

Objectives: We evaluated the results of 14 cases of osteoid osteoma treated with percutaneous drilling resection of the nidus under CT guidance and discussed the positive and negative impact of the same.

Material and Methods: We included 14 patients who presented, from October 2017 to September 2020, at a tertiary level health care center. The diagnosis was established by clinical as well as imaging modalities. The patients underwent CT scan and the exact site was localized. Safe zone for percutaneous drilling was identified using contrast for vascular bundle. Percutaneous drilling was done using 8 mm reamer and complete lesion was removed under CT guidance. Patients were followed up for 2 years after the procedure and the final results were obtained in terms of pain, functional ability of limb and recurrence.

Results: 13 out of 14 patients were pain-free at the end of the follow-up. One patient did have some pain after 1 year and on repeat imaging, there were changes suggestive of recurrence. The success rate was thus 13/14 patients (92.8%). The mean pre-operative pain score improved from 2.3 (range, 0–4) to 4.85 (range, 4–5) after procedure. There was no functional deficit of the limb recorded at the end of final follow up.

Conclusion: CT-guided percutaneous trephination is a cost-effective alternative to available treatments protocols for Osteoid osteoma. Although newer techniques such as radio-frequency ablation are available, they are neither easily accessible nor affordable for the masses in developing countries.
How far is almost strong compactness from strong compactness
Authors: You Zhixing , Yuan Jiachen
Published: October 2023

Bagaria and Magidor introduced the notion of almost strong compactness, which is very close to the notion of strong compactness. Boney and Brooke-Taylor asked whether the least almost strongly compact cardinal is strongly compact. Goldberg gives a positive answer in the case [Formula: see text] holds from below and the least almost strongly compact cardinal has uncountable cofinality. In this paper, we give a negative answer for the general case. Our result also gives an affirmative answer to a question of Bagaria and Magidor.
Halin’s infinite ray theorems: Complexity and reverse mathematics
Authors: Barnes James S. , Goh Jun Le , Shore Richard A.
Published: October 2023

Halin in 1965 proved that if a graph has [Formula: see text] many pairwise disjoint rays for each [Formula: see text] then it has infinitely many pairwise disjoint rays. We analyze the complexity of this and other similar results in terms of computable and proof theoretic complexity. The statement of Halin’s theorem and the construction proving it seem very much like standard versions of compactness arguments such as König’s Lemma. Those results, while not computable, are relatively simple. They only use arithmetic procedures or, equivalently, finitely many iterations of the Turing jump. We show that several Halin-type theorems are much more complicated. They are among the theorems of hyperarithmetic analysis. Such theorems imply the ability to iterate the Turing jump along any computable well ordering. Several important logical principles in this class have been extensively studied beginning with work of Kreisel, H. Friedman, Steel and others in the 1960s and 1970s. Until now, only one purely mathematical example was known. Our work provides many more and so answers Question 30 of Montalbán’s Open Questions in Reverse Mathematics in 2011. Some of these theorems including ones in Halin in 1965 are also shown to have unusual proof theoretic strength as well.
About Central Bank Digital Currencies (CBDCs)
Authors: Francis Jack Clark
Published: October 2023

A Central Bank Digital Currency (CBDC) is a country’s fiat currency that exists in a digital form. This digital currency becomes a liability on the balance sheet of a nation’s central bank when it ceases to be a liability on the balance sheet of one of the nation’s commercial banks and gets transferred to the central bank. Instead of printing paper money, the central bank can create CBDCs by opening electronic bank accounts at commercial banks that are backed by the full faith and credit of the nation’s central bank. The goal of a CBDC is to provide the nation’s government, businesses and consumers with a liquid and accessible currency that supplies privacy, transferability, convenience, and financial security. If CBDCs become highly popular, someday the world might operate with only one global CBDC.
Graded dimensions and monomial bases for the cyclotomic quiver Hecke algebras
Authors: Hu Jun , Shi Lei
Published: October 2023

In this paper we give a closed formula for the graded dimension of the cyclotomic quiver Hecke algebra [Formula: see text] associated to an arbitrary symmetrizable Cartan matrix [Formula: see text], where [Formula: see text] and [Formula: see text]. As applications, we obtain some necessary and sufficient conditions for the KLR idempotent [Formula: see text] (for any [Formula: see text]) to be nonzero in the cyclotomic quiver Hecke algebra [Formula: see text]. We prove several level reduction results which decompose [Formula: see text] into a sum of some products of [Formula: see text] with [Formula: see text] and [Formula: see text], where [Formula: see text] for each [Formula: see text]. Finally, we construct some explicit monomial bases for the subspaces [Formula: see text] and [Formula: see text] of [Formula: see text], where [Formula: see text] is arbitrary and [Formula: see text] is a certain specific [Formula: see text]-tuple defined in (5.1).
Prime ideals in infinite products of commutative rings
Authors: Finocchiaro Carmelo A. , Frisch Sophie , Windisch Daniel
Published: October 2023

We describe the prime ideals and, in particular, the maximal ideals in products [Formula: see text] of families [Formula: see text] of commutative rings. We show that every maximal ideal is induced by an ultrafilter on the Boolean algebra [Formula: see text], where [Formula: see text] is the spectrum of maximal ideals of [Formula: see text], and [Formula: see text] denotes the power set. If every [Formula: see text] is in a certain class of rings including finite character domains and one-dimensional domains, we completely characterize the maximal ideals of [Formula: see text]. If every [Formula: see text] is a Prüfer domain, we completely characterize all prime ideals of [Formula: see text].
Properties of gradient maps associated with action of real reductive group
Authors: Biliotti L. , Windare Oluwagbenga Joshua
Published: October 2023

Let [Formula: see text] be a Kähler manifold and let [Formula: see text] be a compact connected Lie group with Lie algebra [Formula: see text] acting on [Formula: see text] and preserving [Formula: see text]. We assume that the [Formula: see text]-action extends holomorphically to an action of the complexified group [Formula: see text] and the [Formula: see text]-action on [Formula: see text] is Hamiltonian. Then there exists a [Formula: see text]-equivariant momentum map [Formula: see text]. If [Formula: see text] is a closed subgroup such that the Cartan decomposition [Formula: see text] induces a Cartan decomposition [Formula: see text] where [Formula: see text], [Formula: see text] and [Formula: see text] is the Lie algebra of [Formula: see text], there is a corresponding gradient map [Formula: see text]. If [Formula: see text] is a [Formula: see text]-invariant compact and connected real submanifold of [Formula: see text] we may consider [Formula: see text] as a mapping [Formula: see text] Given an [Formula: see text]-invariant scalar product on [Formula: see text], we obtain a Morse like function [Formula: see text] on [Formula: see text]. We point out that, without the assumption that [Formula: see text] is a real analytic manifold, the Lojasiewicz gradient inequality holds for [Formula: see text]. Therefore, the limit of the negative gradient flow of [Formula: see text] exists and it is unique. Moreover, we prove that any [Formula: see text]-orbit collapses to a single [Formula: see text]-orbit and two critical points of [Formula: see text] which are in the same [Formula: see text]-orbit belong to the same [Formula: see text]-orbit. We also investigate convexity properties of the gradient map [Formula: see text] in the Abelian case. In particular, we study two-orbit variety [Formula: see text] and we investigate topological and cohomological properties of [Formula: see text].
Neural Network-Based Anomaly Data Classification and Localization in Bridge Structural Health Monitoring
Authors: Li Yahao , Zhang Nan , Sun Qikan , Cai Chaoxun , Li Kebing
Published: October 2023

Due to the harsh working environments of certain bridges, the bridge structural health monitoring systems (SHMs) are prone to error warning because of anomaly data. Therefore, it is of great significance to accurately classify and locate the anomaly data for effectively addressing these issues. This paper proposes a method for classifying and locating anomaly data utilizing one-dimensional monitoring data based on convolutional neural networks. Compared to previous research reliant on visual features, the proposed method has lower computational costs. By incorporating the anomaly data localization network, manual localization operations for data restoration are replaced. The analysis in this paper is based on monitoring data from a large-span cable-stayed bridge, along with artificially generated anomaly data. The two neural network frameworks proposed in this paper are trained and validated, showcasing precise classification and localization of anomaly data. Furthermore, the paper discusses the impact of common errors in labeling data categories and locating training samples in practical operations. The results demonstrate that even in the presence of noticeable yet non-extreme labeling errors in the training set, the proposed method still achieves accurate classification and localization, highlighting its robustness.
Dynamic Responses of a Shallow Lined Tunnel with Imperfect Interface Under Transient P Wave
Authors: Xia Yuanyou , Han GaoSheng , Mei Wanquan , Pan Peng-Zhi , Li Mei , Yan Minjia , Yan Yaofeng
Published: October 2023

Shallow-buried cavities and underground structures are inevitably subjected to transient perturbation from earthquakes or engineering activities during their life circle, leading to the occurrence of dynamic failure. The investigation presented by this paper concentrates on the dynamic responses triggered by an aperiodic transient [Formula: see text] wave around a circular lined tunnel with an imperfect interface in a half-space and the spring model is employed to describe the interface between rock mass and liner. Resorting to the wave function expansion scheme, the large arc assumption, the Graf’s addition theorem and the numerical inversion algorithm of Laplace transformation, the dynamic responses around a circular shallow lined tunnel with an imperfect interface are evaluated theoretically. The good agreement of time–history curves and contour snapshots for stress between the theoretical solutions and the numerical counterparts validates the analytical scheme. The effect of disturbance direction, embedment depth, thickness of liner and interface coefficients on the dynamic responses around the shallow-buried lined tunnel is analyzed. The results indicate that the positions of peak hoop dynamic stress concentration factor (DSCF) are approximately perpendicular to the perturbation direction. The DSCF distributions converge to be stable when the ratio of embedment depth to excavation radius exceeds 10.0. The thickness of the liner mainly affects the dynamic responses around the interface. Increase of elastic coefficient induces a decreasing DSCF in rock mass and an increasing counterpart in the liner. The results may provide the theoretical basis for the transient responses and aseismic design of underground tunnels.
Dynamic Characteristics of a Supercritical Helicopter Tail Transmission System with Self-Excited Vibration and Rubbing Impact
Authors: Zhu Haimin , Hu Shunan , Zhang Li , Li Miaomiao , Zhu Rupeng
Published: October 2023

This study presented a novel analytical method to investigate the coupled dynamic behavior of a supercritical helicopter tail transmission system, taking into account the friction-induced self-excitation of the floating spline, the rubbing between the limiting ring device and the shaft, and the time-varying meshing excitation experienced by multiple spiral bevel gear pairs. The tail transmission shaft was first modeled using Timoshenko beam elements in local coordinates. Subsequently, the centralized parameter method was employed to build dynamic models of critical components such as the floating spline, limiting ring devices, and multiple spiral bevel gear pairs. Finally, the system’s dynamic equations were derived utilizing the interface coordination principle and spatial coordinate transformation. Numerical analyses were conducted to examine the dynamic behavior of the system, including the coupled vibration properties and the impact laws of the limiting ring device and floating spline on the system’s response. The findings indicated that the limiting ring device resulted in a cross-critical vibration reduction in the tail horizontal shaft, achieved through the mechanisms of dry friction and rubbing impact. However, as a consequence, the natural and rubbing frequencies of the other shafts were generated. The self-excited vibration of the system, brought about by the friction of the spline tooth surface, had a significant impact on the shaft that was directly connected. The emergence of the self-excited vibration occurred when the speed surpassed the first-order natural speed of the directly connected shaft, with the corresponding self-excited frequency being the first-order natural frequency of said shaft. With the increase in the tooth surface friction coefficient of the spline, it even caused continuous rubbing between the shaft and the limiting ring device under a supercritical condition. The proposed dynamic analysis approach holds promise in offering theoretical guidance for the reduction of vibration and noise generated in supercritical tail transmission systems.
Dynamic Responses and Nonlinear Characteristics of a Nonlinear Absorber with Euler-Buckled Beams for Spacecraft Flywheel Systems
Authors: Zhang Jun , Liu Haiping , Shen Dashan , Quan Chunri
Published: October 2023

In order to effectively mitigate the micro-vibration energy from the on-orbit flywheel and high-level vibration transmitted to flywheel system in the launching stage, a nonlinear vibration absorber (NVA) with Euler-buckled beams is developed and investigated in this paper. The NVA is composed of a linear supporting spring and a set of parallel Euler-buckled beams which is used as a negative stiffness corrector. In order to evaluate vibration reduction performance and stability characteristics of this developed nonlinear coupled dynamic system with NVA. First of all, a multi-degree-of-freedom compound dynamic model, including the flywheel system, the NVA and the supporting structural plate in the satellite platform, is built. Then, based on the systematic dynamic equations, the approximate steady-state solutions are derived by using the complexification-averaging (CX-A) method under on-orbit and launching loads, respectively. The analytical method and solutions are validated by using the numerical method. The proposed NVA can realize excellent vibration mitigation performance for the three-degree-of-freedom (3-DOF) coupled nonlinear system under the launching and on-orbit excitations. Next, the slow-variable manifold equation is analyzed to address the dynamic bifurcation behaviors of the nonlinear compound system and the influences of the excitation amplitude on the bifurcation characteristics are focused on. The results show that a 3-DOF system is more prone to instability and requires larger external excitation to escape the instability region. The calculation results also show that the stiffness ratio and excitation amplitude have significant effects on the bifurcation characteristics, and a proper stiffness ratio can be chosen to avoid bifurcations. Finally, compared with typical pure cubic stiffness NVA, the proposed NVA exhibits greater adaptability, and can work efficiently for a relatively larger range of excitation amplitude.