bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical and experimental research on the mechanical tests of 3D printed samples from various materials
Authors: Dimitrescu A , Babiş C , Fica S A , Stochioiu C , Vlăsceanu D , Baciu F
Published: March 2024

At this moment, a real industrial, scientific and technological revolution is being discussed worldwide, consisting in the development of Additive Manufacturing AM technologies through the use of 3D printing. The FDM (Fused Deposition Modelling) 3D printing technology consists in the deposition of fusible material layer by layer in the XOY plane, the thickness of the 3D printed layer is g = 0.12 ÷ 0.24 mm, the resolution of 3D printing is r = 0.1mm, while the print head advances vertically on the OZ axis. The purpose of the work is to determine the breaking moment through destructive mechanical bending tests of some samples made by 3D printing from the following materials: ABS+, PETG and PLA. 5 samples were made in 3 printing directions: horizontal, vertical and lateral, resulting in 15 samples for each material. The total number of samples used is 45. Knowing these values, depending on the requirements of the specifications, a certain material and a certain printing position can be used.
Dummy kinematics in frontal impact, comparison of simulations in Madymo with sled tests
Authors: Nedelescu C , Chiru A , Vrabie P , Trusca D
Published: March 2024

The paper aims to respond to the current requirements regarding the usage of modern virtual analysis tools in accidentology research, presenting the methods of performing the virtual and experimental studies. The main objective of this paper is to determine the movement of the dummy by comparing the kinematic parameters provided by the simulations performed in Madymo with the experimental tests (sled tests). A prototype test device was used to analyse the movement of the dummy in a vehicle cabin at different impact situations of a frontal collision. The experiment was performed for two different cases: with seatbelt and without seatbelt. For the virtual study in Madymo two different setups were prepared in order to obtain the results for both testcases based on a parameterized model. The analysis of the results is performed by comparison, between experimental results and simulation results. Three different phases are taken into consideration in order to make a study of a frontal collision: pre-collision, collision and post-collision.
Numerical analysis and evaluation of a semi-heavy guardrail system
Authors: Gheres M I , Cordos N , Todorut A
Published: March 2024

The continuous increase in traffic accidents, following the rise in the number of vehicles in traffic and their speed, requires the development of research on the design of active and passive safety systems. This research mainly aims to compare the performance of commonly used passive safety systems (semi-heavy W-beam guardrails) mounted on roadside and pedestrian bridges to protect vehicles and pedestrians. It is intended to reduce the deformations of the vehicle upon impact with the protective device mounted between the roadside and the pedestrian area for the protection of the vehicle occupants; reduce the parapet working width for the pedestrian’s safety; and maintain the vehicle’s trajectory from the moment of impact to the final movement, between the guardrail and the median axis of the road, to ensure the protection of other road users. A CAD model of the vehicle-guardrail scenario was developed to achieve these objectives. Load simulation cases are performed using the finite element method according to the European standards SR EN 1317 for impact tests of vehicles - TB 42, recommended for semi-heavy guardrails.
Seat belt modelling and testing through virtual prototyping
Authors: Stănciuc-Oţăt O V , Dumitru I , Tutunea D , Florescu B
Published: March 2024

Road safety requires optimal collaboration and coordination between several factors directly or indirectly involved in order to ensure safety for all public road users within a national transport system. Within this system the tasks of each component must be very clearly defined and regulated so that the whole system functions properly. The paper presents a case study on the operation of the driver restraint system in the driving position. For this purpose, the three-point seat belt was modeled using the LS-Dyna software package. For the proposed analysis, the seat belt with grip on the central pillar of the vehicle was considered. This type of seat belt is the most common passive safety system in series vehicles.
Analysis of the aerodynamic performance of truck semi-trailers
Authors: Vieru E M , Stan C , Ilea L
Published: March 2024

In the last time, trucks have shown a very high interest in terms of their technical and fuel consumption performance. Prioritizing the phenomenon of having trucks that transport as much, as quickly and as economically as possible, this represent a new challenge for industry and engineering, which are in continuous development. The attempt to create a bridge as stable as possible between technical and consumer performance is supported by the multitude of areas that, based on studies and experimental trials, allow optimization without interfering, substantially, with the actual transport of the goods (loading capacities and transport). The main objective of this paper is to present the possibility of improving the aerodynamic performance of trucks, focusing on semi-trailers. For this study, a truck modelled at one to one scale was used, whose aerodynamic performance was verified in the virtual environment (CFD–Computational Fluid Dynamics); this environment has the possibility to test several geometric models without requiring the layout of a vehicle in physical form. To check the performance, a basic model was created, a conventional truck (tractor unit with semi-trailer), to which various semi-trailer modifications were made, such as: total and partial coverage of the side areas, idea to create a more aerodynamic profile of the semi-trailer in the back and the addition of fairings under the platform (underbody of the semi-trailer). The results describe the impact these elements have and allow the visualization of the possible future profile that is as aerodynamic as possible for semi-trailers (therefore also for trucks) from both theoretical and technical point of view. Through the proposed improvements the capacity and the transport of the goods is not affected, in a significant way so it can be said that there is the possibility of implementation in the industry.
Considerations on traffic management in isolated intersections
Authors: Dragu V , Oprea F C , Roman E A
Published: March 2024

The continuous growth in the number of motor vehicles in major cities, combined with a stagnant development of road infrastructure, has caused traffic congestion and a range of negative direct and indirect effects. Even if measures were proposed to improve the road infrastructure, such as increasing connectivity or the size of the roads, the benefits would only be temporary, as it is well known that any infrastructure improvement will attract new traffic. The aim of this study is to identify traffic management measures at conflict points in road infrastructure that can improve traffic flow parameters. The study categorizes conflict points as either saturated or unsaturated intersections in order to determine a precise mathematical model for the timing of traffic light cycles that is suitable for local traffic conditions. The theoretical assertions are supported by a case study and conclusions and recommendations are formulated for use in the practice of traffic lights at isolated intersections.
Research on the influence of traffic conditions on noise level in the passenger compartment of motor vehicles
Authors: Neamțu G , Țîțu A M , Boroiu A A , Boroiu A
Published: March 2024

The research investigates the noise levels measured in the passenger compartments of several automobiles. These vehicles are powered by various engines, travel on various highways, and function at differing speeds and acceleration. The results are visually processed using specialist software. The study investigates the effects of three major sources of automotive noise: engine operation, tire-road contact, and friction between the car body and the air. The immis noise in the passenger compartment is reported to be mostly impacted by the engine’s operational characteristics (load and speed) at lower speeds. In contrast, as travel speed increases, the noise produced by tire-road contact becomes more substantial, and at greater speeds, the noise produced by the interaction between the car body and the air becomes more significant. As a result, the engine type, tire and road characteristics, vehicle speed, and passenger compartment acoustic insulation are all important elements in influencing noise emission in the passenger compartment.
Spectral bounds for periodic Jacobi matrices
Authors: Hati̇noğlu Burak
Published: March 2024

We consider periodic Jacobi operators and obtain upper and lower estimates on the sizes of the spectral bands. Our proofs are based on estimates on the logarithmic capacities and connections between the Chebyshev polynomials and logarithmic capacity of compact subsets of the real line.
Symmetric function generalizations of the 𝑞-Baker–Forrester ex-conjecture and Selberg-type integrals
Authors: Xin Guoce , Zhou Yue
Published: March 2024

It is well-known that the famous Selberg integral is equivalent to the Morris constant term identity. In 1998, Baker and Forrester conjectured a generalization of the

q
q

-Morris constant term identity[J. Combin. Theory Ser. A 81 (1998), pp. 69–87]. This conjecture was proved and extended by Károlyi, Nagy, Petrov, and Volkov (KNPV) in 2015 [Adv. Math. 277 (2015), pp. 252–282]. In this paper, we obtain two symmetric function generalizations of the

q
q

-Baker–Forrester ex-conjecture. These include: (i) a

q
q

-Baker–Forrester type constant term identity for a product of a complete symmetric function and a Macdonald polynomial; (ii) a complete symmetric function generalization of KNPV’s result.
Reclassification of a reveromycin-producer and the proposals of Actinacidiphila reveromycinica sp. nov. and Actinacidiphila acidipaludis comb. nov.
Authors: Komaki Hisayuki , Takagi Hiroshi , Takahashi Shunji , Osada Hiroyuki
Published: March 2024

Streptomyces sp. SN-593, a reveromycin-producer, was previously thought to belong to the genus Streptomyces based on the morphological and chemotaxonomic characteristics. In this paper, we re-considered its taxonomic position according to the current criteria. Phylogenetic analysis using 16S rRNA gene sequences showed that the strain belongs to the genus Actinacidiphila. In multilocus sequence and phylogenomic analyses, the strain SN-593 represented a distinct evolutionary lineage within this genus and its closest neighbor was A. yanglinensis. Digital DNA-DNA hybridization indicated that the strain shares less than 32% DNA-DNA relatedness with the type strains of closely related species, confirming this strain is a novel genomospecies. According to its phenotypic distinctiveness from the closest neighbor, we propose Actinacidiphila reveromycinica sp. nov. for the strain SN-593T. Additionally, as Streptomyces acidipaludis belonged to the genus Actinacidiphila in these analyses, it should be transferred to the genus, for which Actinacidiphila acidipaludis comb. nov. is proposed.
A variance-partitioning approach for assessing mate choice and which sex controls mating behavior
Authors: Han Chang S , Hyun Hyoseul
Published: March 2024

Mating behavior arises from interactions between males and females. The precopulatory stage includes various male and female mating behaviors that are potentially influenced (independently or jointly) by each sex, thereby shaping the dynamics of this stage. However, limited attention has been given to determining the relative contributions of males and females to the expression of precopulatory behaviors. Here, we adopted a variance-partitioning approach to assess which sex controls each precopulatory behavior. This approach also enabled us to evaluate the existence of mate choice by assessing whether the expression of precopulatory behavior depends on the identity of the opposite-sex partner. In our study, using the bean bug Riptortus pedestris, we exposed individual males and females to different opposite-sex partners (i.e., mating assays) up to six times. During the mating assay, we measured multiple precopulatory behaviors (e.g., latency to mount, courtship rate, courtship duration, and duration of position change). Variance partitioning showed that the variation in each precopulatory behavior could be attributed solely to either sex but not to both sexes. Hence, the precopulatory stage of R. pedestris comprises a combination of male-controlled and female-controlled behaviors. We also suggested that mate choice was absent in both sexes of R. pedestris in the postmounting and precopulatory stages. Our findings highlight the importance of the variance-partitioning approach in the study of mating behavior, as it facilitates the investigation of whether mate choice occurs at specific mating stages and enhances our understanding of evolutionary dynamics during mating.
Cognitive flexibility in a generalist raptor: a comparative analysis along an urbanization gradient
Authors: Biondi Laura Marina , Medina Aanalía , Bonetti Eugenia Andrea , Paterlini Carla Angela , Bó María Susana
Published: March 2024

In this study, we analyzed the variation in cognitive flexibility in the Chimango Caracara (Milvago chimango), across areas with different levels of urbanization. To assess this, we utilized the reversal learning assay which measures the ability to adapt behavior in response to changes in environmental contingencies. We also investigated the impact of neophobia on this variation. All chimangos studied succeeded in acquiring a color-reward association and reverting this learned association when the contingencies changed. Urban chimangos were faster than their rural and suburban counterparts during the initial discrimination and reversal phases. The reversal phase proved to be the most challenging task. The analysis of the errors made during this phase revealed that acquiring a new association (i.e. regressive errors) was challenging for the individuals studied, in comparison to inhibiting a previously learned one (i.e. perseverative errors). Neophobia was found to be lower in urban individuals compared to suburban and rural raptors. Moreover, neophobia showed a correlation with regressive errors during the reversal phase among rural and suburban chimangos, while no such correlation was observed among city-dwelling chimangos. We suggest that neophobia acted as a regulating factor of cognitive flexibility, mainly for individuals expressing relatively high levels of this personality trait.
Negotiating Access to Hard-to-Reach Populations through Institutional Gatekeepers in Social Work Research
Authors: Gřundělová Barbora , Broskevičová Zuzana , Kowolová Iveta
Published: March 2024

Institutional gatekeepers play an increasingly important role in social work research, and their involvement in the research process is essential for the development of a usable knowledge base. This article explores the experience of recruiting participants through institutional gatekeepers for research on hard-to-reach populations in social work. The article aims to find out how researchers negotiate access to research participants with institutional gatekeepers. A qualitative research strategy was used to accomplish this goal. Semi-structured, in-depth interviews with researchers revealed that the researchers enter into negotiations with institutional gatekeepers with some idea of the challenges and risks, but in part they enter into the unknown and are forced to make situational assessments in joint interactions. Research evolves and transforms based on how the researcher moves through the research process, what types of gatekeepers the researcher seeks at different stages of the research process and for what purpose. We identified three basic forms of negotiating access with institutional gatekeepers: logistical assistance, barter transaction and trust-based collaboration. This article looks at the different kinds of relationships that exist between researchers, gatekeepers and hard-to-reach population. It examines the power dynamics involved in the recruitment of marginalised groups through gatekeepers in social work research.
From data to diagnosis: skin cancer image datasets for artificial intelligence
Authors: Wen David , Soltan Andrew , Trucco Emanuele , Matin Rubeta N
Published: March 2024

Artificial intelligence (AI) solutions for skin cancer diagnosis continue to gain momentum, edging closer towards broad clinical use. These AI models, particularly deep-learning architectures, require large digital image datasets for development. This review provides an overview of the datasets used to develop AI algorithms and highlights the importance of dataset transparency for the evaluation of algorithm generalizability across varying populations and settings. Current challenges for curation of clinically valuable datasets are detailed, which include dataset shifts arising from demographic variations and differences in data collection methodologies, along with inconsistencies in labelling. These shifts can lead to differential algorithm performance, compromise of clinical utility, and the propagation of discriminatory biases when developed algorithms are implemented in mismatched populations. Limited representation of rare skin cancers and minoritized groups in existing datasets are highlighted, which can further skew algorithm performance. Strategies to address these challenges are presented, which include improving transparency, representation and interoperability. Federated learning and generative methods, which may improve dataset size and diversity without compromising privacy, are also examined. Lastly, we discuss model-level techniques that may address biases entrained through the use of datasets derived from routine clinical care. As the role of AI in skin cancer diagnosis becomes more prominent, ensuring the robustness of underlying datasets is increasingly important.
Organoids as a tool to study homeostatic and pathological immune–epithelial interactions in the gut
Authors: Kromann Emma Højmose , Cearra Ainize Peña , Neves Joana F
Published: March 2024

The intestine hosts the largest immune cell compartment in the body as a result of its continuous exposure to exogenous antigens. The intestinal barrier is formed by a single layer of epithelial cells which separate immune cells from the gut lumen. Bidirectional interactions between the epithelium and the immune compartment are critical for maintaining intestinal homeostasis by limiting infection, preventing excessive immune activation, and promoting tissue repair processes. However, our understanding of epithelial–immune interactions incomplete as the complexity of in vivo models can hinder mechanistic studies, cell culture models lack the cellular heterogeneity of the intestine and when established from primary cell can be difficult to maintain. In the last decade, organoids have emerged as a reliable model of the intestine, recapitulating key cellular and architectural features of native tissues. Herein, we provide an overview of how intestinal organoids are being co-cultured with immune cells leading to substantial advances in our understanding of immune–epithelial interactions in the gut. This has enabled new discoveries of the immune contribution to epithelial maintenance and regeneration both in homeostasis and in disease such as chronic inflammation, infection and cancer. Organoids can additionally be used to generate immune cells with a tissue-specific phenotype and to investigate the impact of disease associated risk genes on the intestinal immune environment. Accordingly, this review demonstrates the multitude of applications for intestinal organoids in immunological research and their potential for translational approaches.
Conspecific cues mediate habitat selection and reproductive performance in a haplodiploid spider mite
Authors: Weerawansha Nuwan , Wang Qiao , He Xiong Zhao
Published: March 2024

Selection of a suitable habitat by animals before settlement is critical for their survival and reproduction. In silk-spinning arthropods like spider mites, denser webs offer protection from predation and serve as a dispersal mode. Settling in habitats with the presence of conspecifics and silk webs can benefit the habitat-searching females. Silk and conspecifics usually coexist, but their distinct effects on female colonization have received little attention. In this study, we used a haplodiploid spider mite, Tetranychus ludeni Zacher (Acari: Tetranychidae), to examine the impact of conspecific cues, including cues from ovipositing conspecifics and silk, on habitat selection and subsequent reproductive performance of females. Results show that females significantly preferred habitats with cues from neighboring conspecifics and silk and neighboring conspecifics induced additive effect to that of silk on habitat selection. Conspecific cues did not boost female reproduction but facilitated females laying larger eggs that were more likely to be fertilized and to develop into daughters. When given a choice between silk-covered and clean habitats, females preferred silk-covered habitats, laid a similar number of eggs with similar size, but produced more daughters, suggesting that T. ludeni females can adjust the size threshold for fertilization in response to the current social environment. Knowledge of this study improves our understanding of spider mite habitat selection and post-settlement reproductive performance behaviors.
Colesevelam has no acute effect on postprandial GLP-1 levels but abolishes gallbladder refilling
Authors: Gether Ida M , Bahne Emilie , Nerild Henriette H , Rehfeld Jens F , Hartmann Bolette , Holst Jens J , Vilsbøll Tina , Sonne David P , Knop Filip K
Published: March 2024

Objective

Colesevelam, a bile acid sequestrant approved for the treatment of hypercholesterolaemia, improves glycaemic control in type 2 diabetes. We hypothesised that single-dose colesevelam increases postprandial GLP-1 secretion, thus, reducing postprandial glucose excursions in individuals with type 2 diabetes. Further, we explored the effects of single-dose colesevelam on ultrasonography-assessed postprandial gallbladder motility, paracetamol absorption (proxy for gastric emptying), and circulating factors known to affect gallbladder motility.

Methods

In a randomised, double-blind, placebo-controlled crossover study, 12 individuals with type 2 diabetes (mean ± SD: age 61 ± 8.8 years; body mass index 29.8 ± 3.0 kg/m2) were subjected to 4 mixed meal tests on separate days; 2 with orally administered colesevelam (3.75 g) and 2 with placebo, with intravenous infusion of the GLP-1 receptor antagonist exendin(9-39)NH2 or saline.

Results

Single-dose colesevelam had no effect on postprandial concentrations of glucose (P = .786), C-peptide (P = .440), or GLP-1 (P = .729), and exendin(9-39)NH2 administration revealed no GLP-1-mediated effects of colesevelam. Colesevelam did not affect gallbladder emptying but abolished gallbladder refilling (P = .001), increased postprandial cholecystokinin (CCK) secretion (P = .010), and decreased postprandial serum concentrations of fibroblast growth factor 19 (FGF19) (P = .035) and bile acids (P = .043).

Conclusion

Single-dose colesevelam had no effect on postprandial GLP-1 responses or glucose tolerance but disrupted postprandial gallbladder refilling by increasing CCK secretion and reducing circulating concentrations of FGF19 and bile acids. These findings leave the antidiabetic actions of colesevelam unresolved but provide mechanistic insights into its effect on gallbladder motility.
Patient–physician sex concordance and outcomes in cardiovascular disease: a systematic review
Authors: Harik Lamia , Yamamoto Ko , Kimura Takeshi , Rong Lisa Q , Vogel Birgit , Mehran Roxana , Bairey-Merz C Noel , Gaudino Mario
Published: March 2024

The sex disparity in outcomes of patients with cardiovascular disease is well-described and has persisted across recent decades. While there have been several proposed mechanisms to explain this disparity, there are limited data on female patient–physician sex concordance and its association with outcomes. The authors review the existing literature on the relationship between patient–physician sex concordance and clinical outcomes in patients with cardiovascular disease, the evidence of a benefit in clinical outcomes with female patient–physician sex concordance, and the possible drivers of such a benefit and highlight directions for future study.
Personality and Risk of Arthritis in Six Longitudinal Samples
Authors: Stephan Yannick , Sutin Angelina R , Canada Brice , Terracciano Antonio
Published: March 2024

Objectives

Personality traits are broadly related to medical conditions, but there is limited research on the association with the risk of arthritis. This multicohort study examines the concurrent and prospective associations between personality traits and arthritis risk.

Methods

Participants (N > 45,000) were mostly middle-aged and older adults from 6 established longitudinal cohorts. Baseline assessments of personality traits, covariates (age, sex, education, race, ethnicity, depressive symptoms, body mass index, and smoking), and arthritis diagnosis were obtained in each sample. Arthritis incidence was assessed over 8–20 years of follow-up.

Results

The meta-analyses identified an association between higher neuroticism and an increased risk of concurrent (odds ratio = 1.20, 95% confidence interval [CI] = 1.16–1.24; p < .001, I2 = 40.27) and incident (hazard ratio = 1.11, 95% CI = 1.08–1.14; p < .001, I2 = 0) arthritis and between higher conscientiousness and a decreased risk of concurrent (odds ratio = 0.88, 95% CI = 0.86-0.90; p < .001, I2 = 0) and incident (hazard ratio = 0.95, 95% CI = 0.92–0.98; p = .002, I2 = 41.27) arthritis. Higher extraversion was linked to lower risk of concurrent (odds ratio = 0.92, 95% CI = 0.88–0.96; p < .001, I2 = 76.09) and incident (hazard ratio = 0.97, 95% CI = 0.95–0.99; p = .018, I2 = 0) arthritis, and openness was related to lower risk of concurrent arthritis (odds ratio = 0.96, 95% CI = 0.93–0.99; p = .006, I2 = 35.86). Agreeableness was unrelated to arthritis. These associations were partially accounted for by depressive symptoms, body mass index, and smoking. There was no consistent evidence of moderation by age or sex.

Discussion

Findings from 6 samples point to low neuroticism and higher conscientiousness as factors that reduce the risk of arthritis.
Who cares? How personal political characteristics are related to online counteractions against hate speech
Authors: Schmid Ursula Kristin , Obermaier Magdalena , Rieger Diana
Published: March 2024

Although many Internet users have encountered hate speech online, interventions against those incidents are unlikely. To learn more about online counteractions against hate speech, which we conceptualize as a form of online civic participation, we conducted an online survey representing adult German Internet users (N = 2,691). We investigated what distinguishes users who intervene against hate speech, focusing on associations between citizens’ prior counteractions and their personal political characteristics, their attributed responsibility for intervening against hate speech to social and political actors, and their institutional trust. Results indicate that especially Internet users’ personal political characteristics (e.g., internal political efficacy, political opinion leadership) as well as trust in regulative political institutions are positively associated with counteracting against online hate speech. While social media use and previous experience with counteractions increased the likelihood of users counteracting against hate speech, authoritarian attitudes and attributing responsibility for intervening to platform operators decreased it.
Examining the role of the digital economy in carbon production efficiency under incentive-based environmental regulations: a spatial spillover perspective
Authors: Hou Jian , Shi Juming , Fan Guoliang
Published: March 2024

As China transitions towards high-standard growth development, the digital economy profoundly influences the formation of a new paradigm for reducing carbon emissions in this new era. This study examines how the digital economy impacts carbon productivity within the framework of incentive-based environmental regulations. Spatial econometric methods were employed for empirical analysis using provincial-level data from 2011 to 2021. The study’s findings suggest that: (I) Within the resource tax weight matrix, the digital economy shows a positive local effect on carbon productivity, a conclusion that withstands robustness testing. (II) Under the spatial Durbin model with heterogeneous coefficients, certain provinces exhibit either positive or negative spillover effects. (III) Both vehicle and vessel taxes and environmental taxes show a dual-threshold effect, while resource taxes demonstrate only a single-threshold effect. Additionally, all these factors present a nonlinear moderating effect that positively influences the relationship. As per these outcomes, this study offers the following proposed actions to foster synergistic development of the economy driven by digital technologies and the effectiveness of carbon production, thus facilitating high-quality, sustainable economic growth: (I) Enhance investment in the development of the digital economy. (II) Implement suitable local resource, environmental, and vehicle and vessel taxes.
Microbial metabolism of caffeine and potential applications in bioremediation
Authors: Mock Meredith B , Summers Ryan M
Published: March 2024

With increasing global consumption of caffeine-rich products, such as coffee, tea, and energy drinks, there is also an increase in urban and processing waste full of residual caffeine with limited disposal options. This waste caffeine has been found to leach into the surrounding environment where it poses a threat to microorganisms, insects, small animals, and entire ecosystems. Growing interest in harnessing this environmental contaminant has led to the discovery of 79 bacterial strains, eight yeast strains, and 32 fungal strains capable of metabolizing caffeine by N-demethylation and/or C-8 oxidation. Recently observed promiscuity of caffeine-degrading enzymes in vivo has opened up the possibility of engineering bacterial strains capable of producing a wide variety of caffeine derivatives from a renewable resource. These engineered strains can be used to reduce the negative environmental impact of leached caffeine-rich waste through bioremediation efforts supplemented by our increasing understanding of new techniques such as cell immobilization. Here, we compile all of the known caffeine-degrading microbial strains, discuss their metabolism and related enzymology, and investigate their potential application in bioremediation.
Strain specific Starmerella bacillaris and Saccharomyces cerevisiae interactions in mixed fermentations
Authors: Englezos Vasileios , Di Gianvito Paola , Serafino Gabriele , Giacosa Simone , Cocolin Luca , Rantsiou Kalliopi
Published: March 2024

Aims

Yeast interactions have a key role in the definition of the chemical profile of the wines. For this reason, winemakers are increasingly interested in mixed fermentations, employing Saccharomyces cerevisiae and non-Saccharomyces strains. However, the outcome of mixed fermentations is often contradictory because there is a great variability among strains within species. Previously, it was demonstrated that the loss of culturability of Starmerella bacillaris in mixed fermentations with S. cerevisiae was due to the physical contact between cells. Therefore, to further explore previous observations, the interaction mechanisms among different strains of Starm. bacillaris and S. cerevisiae during mixed fermentations were investigated.

Methods and results

Fermentations were conducted under conditions that allow physical contact between cells (flasks) but also using a double-compartment fermentation system in which cells of both species were kept separate. The role of competition for nutrients and antimicrobial compounds production on yeast–yeast interaction mechanisms was also investigated. Three Starm. bacillaris and three S. cerevisiae strains were used to investigate if interaction mechanisms are modulated in a strain-specific way. Both species populations were affected by physical contact, particularly Starm. bacillaris that lost its culturability during fermentation. In addition, loss of culturability of Starm. bacillaris strains was observed earlier in flasks than in the double-compartment system. The phenomena observed occurred in a strain couple-dependent way. Starm. bacillaris disappearance seemed to be independent of nutrient depletion or the presence of inhibitory compounds (which were not measured in this study).

Conclusion

Overall, the results of the present study reveal that cell-to-cell contact plays a role in the early death of non-Saccharomyces but the extent to which it is observed depends greatly on the Starm. bacillaris/S. cerevisiae strains tested.
The use of MFN clauses in investment arbitration: the problem of importation
Authors: Villablanca Gutiérrez José Pedro
Published: March 2024

The nature of most-favoured-nation clauses (MFN clauses) is a constant source of debate and controversy. While the traditional position has been that they allow an investor to import provisions from another International Investment Agreement (IIA)—a practice that has been defined by some as ‘importation’1—there is a new trend that considers this a misuse of MFN clauses. This article endorses the latter position and will explain that the practice of importation derives from a misinterpretation of MFN clauses contained in IIAs. This error involves requesting a remedy for the specific performance of the MFN clause without first having claimed its breach. The claimant asks an arbitral tribunal simply to enforce the MFN clause by granting him the same provisions conferred to another investor. However, in this exercise, the investor forgets that, in order for an arbitral tribunal to order such a remedy, it must first be proven that such an obligation exists and was breached by the host state.
Agency consultation networks in environmental impact assessment
Authors: Wang Jie , Ulibarri Nicola , Scott Tyler A
Published: March 2024

Government agencies practice interagency consultation to ensure that broader governmental activities align with their missions and objectives. Consultation allows agencies not only to express their preferences and interests, but also may create administrative burden and procedural delay. To explore the conditions under which agencies choose to review activities proposed by fellow government actors, this research focuses on the California Environmental Quality Act (CEQA), California’s environmental impact assessment law. We conceptualize the CEQA review network as a two-mode network, in which each review agency is linked to particular projects, and use two-mode exponential random graph models to test a series of hypotheses about agency, project, and agency–project dyadic characteristics that shape the choice to review. We find that projects located in sites with socioeconomically vulnerable residents or higher levels of background pollution garner more consultation. Agencies are more likely to provide consultation when their expertise aligns with the project’s impact, and are less likely to review a project with agencies that possess the same expertise. This research highlights variations underlying interagency consultation and helps understand how agencies try to influence other agencies’ decisions.
Abundance stratification in type Ia supernovae – VII. The peculiar, C-rich iPTF16abc: highlighting diversity among luminous events
Authors: Aouad Charles J , Mazzali Paolo A , Ashall Chris , Tanaka Masaomi , Hachinger Stephan
Published: March 2024

Observations of Type Ia supernovae (SNe Ia) reveal diversity, even within assumed subcategories. Here, the composition of the peculiar iPTF16abc (SN 2016bln) is derived by modelling a time series of optical spectra. iPTF16abc’s early spectra combine traits of SNe 1999aa and 1991T known for weak Si ii λ 6355 and prominent Fe iii features. However, it differs with weak early Fe iii lines, and persistent C ii lines post-peak. It also exhibits a weak Ca ii H&K feature aligning it with SN 1991T, an observation supported by their bolometric light curves. The early attenuation of Fe iii results from abundance effect. The weakening of the Si ii λ 6355 line, stems from silicon depletion in the outer shells, a characteristic shared by both SNe 1999aa and 1991T, indicating a common explosion mechanism that terminates nuclear burning at around 12 000 km s−1 unseen in normal events. Beneath a thin layer of intermediate mass elements (IMEs) with a total mass of 0.18 M⊙, extends a 56Ni rich shell totaling 0.76 M⊙ and generating a bolometric luminosity as high as Lpeak = 1.60 ± 0.1 × 1043 ergs s−1. Inner layers, typical of SNe Ia, hold neutron-rich elements, (54Fe and 58Ni), totaling 0.20 M⊙. Stable iron, exceeding solar abundance, and carbon, coexist in the outermost layers, challenging existing explosion models. The presence of carbon down to v ≈ 9000 km s−1, totalling ∼0.01 M⊙ unprecedented in this class, links iPTF16abc to SN 2003fg-like events. The retention of 91T-like traits in iPTF16abc underscores its importance in understanding the diversity of SNe Ia.
Episodic eruptions of young accreting stars: the key role of disc thermal instability due to Hydrogen ionization
Authors: Nayakshin Sergei , Cruz Sáenz de Miera Fernando , Kóspál Ágnes , Ćalović Aleksandra , Eislöffel Jochen , Lin Douglas N C
Published: March 2024

In the classical grouping of large magnitude episodic variability of young accreting stars, FU Ori type objects (FUORs) outshine their stars by a factor of ∼100, and can last for up to centuries; EX Lupi type ones (EXORs) are dimmer, and last months to a year. A disc Hydrogen ionization thermal instability (TI) scenario was previously proposed for FUORs but required unrealistically low disc viscosity. In the last decade, many intermediate-type objects, for example, FUOR-like in luminosity and spectra but EXOR-like in duration were found. Here, we show that the intermediate-type bursters Gaia20eae, PTF14jg, Gaia19bey, and Gaia21bty may be naturally explained by the TI scenario with realistic viscosity values. We argue that TI predicts a dearth (desert) of bursts with peak accretion rates between 10−6 ${\rm {\rm M}_{\odot }}$ yr−1$\lesssim \dot{M}_{\rm burst} \lesssim 10^{-5}$ ${\rm {\rm M}_{\odot }}$ yr−1, and that this desert is seen in the sample of all the bursters with previously determined $\dot{M}_{\rm burst}$. Most classic EXORs (FUORs) appear to be on the cold (hot) branch of the S-curve during the peak light of their eruptions; thus TI may play a role in this class differentiation. At the same time, TI is unable to explain how classic FUORs can last for up to centuries, and overpredicts the occurrence rate of short FUORs by at least an order of magnitude. We conclude that TI is a required ingredient of episodic accretion operating at R ≲ 0.1 au, but additional physics must play a role at larger scales. Knowledge of TI inner workings from related disciplines may enable its use as a tool to constrain the nature of this additional physics.
Near-infrared spectroscopic indices for unresolved stellar populations. III. Composite indices definition as age and metallicity tracers and model comparison
Authors: Gasparri D , Morelli L , Cuomo V , Ivanov V D , Pizzella A , François P , Coccato L , Corsini E M , Costantin L , Dalla Bontà E , Méndez-Abreu J , Aguerri J A L
Published: March 2024

Recent advances in the stellar population studies of unresolved galaxies in the NIR domain demonstrated that it contains several line-strength indices to be potentially used as diagnostics for stellar population properties. Reduction of the extinction and possibility to disentangle different stellar populations dominating different spectral ranges are obviously beneficial. To this aim, we have investigated the connections between 19 Lick/IDS indices and 39 NIR indices measured in the central regions of 32 galaxies observed with X-shooter. We adopted a systematic approach to deriving a correlation matrix using all the optical and NIR indices measured for the galaxies and building new NIR composite indices to maximize their correlations with the best age and metallicity optical tracers. We found that the new T1 and [AlFeCr] composite indices are promising age and metallicity diagnostics in NIR, respectively. We finally tested the T1 and [AlFeCr] indices with the predictions of simple stellar populations models, and we found that the models show a general agreement with the data. Some fine tuning and further comparison between models and data, which are now largely available, is necessary to reach the prediction level of the optical line-strength indices.
A link between the size and composition of comets
Authors: Robinson James E , Malamud Uri , Opitom Cyrielle , Perets Hagai , Blum Jürgen
Published: March 2024

All cometary nuclei that formed in the early Solar System incorporated radionuclides and therefore were subject to internal radiogenic heating. Previous work predicts that if comets have a pebble-pile structure internal temperature build-up is enhanced due to very low thermal conductivity, leading to internal differentiation. An internal thermal gradient causes widespread sublimation and migration of either ice condensates, or gases released from amorphous ice hosts during their crystallization. Overall, the models predict that the degree of differentiation and re-distribution of volatile species to a shallower near-surface layer depends primarily on nucleus size. Hence, we hypothesize that cometary activity should reveal a correlation between the abundance of volatile species and the size of the nucleus. To explore this hypothesis, we have conducted a thorough literature search for measurements of the composition and size of cometary nuclei, compiling these into a unified data base. We report a statistically significant correlation between the measured abundance of CO/H2O and the size of cometary nuclei. We further recover the measured slope of abundance as a function of size, using a theoretical model based on our previous thermophysical models, invoking re-entrapment of outward migrating high volatility gases in the near-surface pristine amorphous ice layers. This model replicates the observed trend and supports the theory of internal differentiation of cometary nuclei by early radiogenic heating. We make our data base available for future studies, and we advocate for collection of more measurements to allow more precise and statistically significant analyses to be conducted in the future.
Non-thermal broadening of coronal lines in a 3D MHD loop model
Authors: Breu C A , Peter H , Solanki S K , Cameron R , De Moortel I
Published: March 2024

Observed spectral profiles of emission lines from the corona are found to have widths exceeding the thermal line width. To investigate the physical mechanism, we run a 3D magnetohydrodynamics model of a single, straightened loop in which we partially resolve turbulent motions that form in response to the driving by self-consistently evolving magneto-convection in the photosphere. The convective motions shear and twist the magnetic field lines, leading to heating. From the model, we synthesize spectral profiles of emission lines forming at temperatures around and above 1 MK. The coronal heating process generates a range of velocity amplitudes and directions structured on a scale much smaller than the resolving power of current instruments, leading to a broadening of the spectral lines. Our model includes the mass exchange between corona and chromosphere, thus we also capture flows parallel to the loop axis. We find that the spectral lines show a non-thermal line broadening roughly consistent with observations for a viewing angle perpendicular to the axis. The broadening through field-parallel flows is comparable, although slightly smaller. The line broadening is independent of the instrument resolution for a perpendicular line of sight (LOS). We can connect the non-thermal line broadening to heating events and flows. While small-scale velocities along the LOS are mainly responsible for the broadening observed perpendicular to the loop, chromospheric evaporation is important for the line broadening observed along the loop. The model reproduces observed values for non-thermal line widths. In the model, these result from continuous driving by magnetoconvection, without imposing driving motions or starting from an already braided field.
On the properties of free-floating planets originating in circumbinary planetary systems
Authors: Coleman Gavin A L
Published: March 2024

Free-floating planets are a new class of planets recently discovered. These planets don’t orbit within stellar systems, instead living a nomadic life within the galaxy. How such objects formed remains elusive. Numerous works have explored mechanisms to form such objects, but have not yet provided predictions on their distributions that could differentiate between formation mechanisms. In this work we form these objects within circumbinary systems, where these planets are readily formed and ejected through interactions with the central binary stars. We find significant differences between planets ejected through planet–planet interactions and those by the binary stars. The main differences that arise are in the distributions of excess velocity, where binary stars eject planets with faster velocities. These differences should be observable amongst known free-floating planets in nearby star-forming regions. We predict that targeted observations of directly imaged free-floating planets in these regions should be able to determine their preferred formation pathway, either by planet formation in single or multiple stellar systems, or through processes akin to star formation. Additionally, the mass distributions of free-floating planets can yield important insights into the underlying planet populations. We find that for planets more massive than 20 $\, {\rm M}_{\hbox{$\oplus $}}$, their frequencies are similar to those planets remaining bound and orbiting near the central binaries. This similarity allows for effective and informative comparisons between mass distributions from microlensing surveys, to those of transit and radial velocities. Ultimately, by observing the velocity dispersion and mass distribution of free-floating planets, it will be possible to effectively compare with predictions from planet formation models, and to further understand the formation and evolution of these exotic worlds.
Treatment for complete extensor tendon rupture: A case report on extensor pollicis longus tendon transfer and tenodesis procedure to radius for a patient with rheumatoid arthritis
Authors: Kohata Kazuhiro , Miyake Takafumi , Morizaki Yutaka , Sasaki Takahiro , Tanaka Sakae
Published: March 2024

The complete loss of finger extension leads to significant inconvenience in daily life and often requires surgical treatment. Despite some disadvantages, the Boyes method, which uses the flexor digitorum superficialis tendon, is commonly performed for complete extensor rupture. We report the case of a 73-year-old woman living alone diagnosed with a subcutaneous rupture of all extensor tendons from the index to the little finger. The favourable range of motion of her wrist allowed us to perform extensor tenodesis. Additionally, the patient had a dislocated thumb interphalangeal (IP) joint, enabling us to use the extensor pollicis longus tendon for tendon transfer in combination with thumb IP joint fusion. The patient demonstrated favourable finger range-of-motion outcomes at the 6-month postoperative assessment. The case shows that extensor pollicis longus tendon transfer and tenodesis may be a viable treatment option for patients with complete extensor rupture accompanied by thumb IP joint deformity and normal wrist range of motion.