bluuebunny/crossref_metadata_2025_split huggingface dataset:
Convergence of summability means of higher dimensional Fourier series and Lebesgue points
Authors: Weisz F. 
Published: February 2025

Abstract
We introduce a new concept of Lebesgue points for higher dimensional
functions. Every continuity point is a Lebesgue point and almost every
point is a Lebesgue point of an integrable function. Given a strictly increasing
continuous function

$$\delta$$

δ

, we prove that the Fejér or Cesàro means

$$\sigma_n^{\alpha}f$$

σ
n
α

f

of the Fourier
series of a two-dimensional function

$$f\in L_1(\mathbb{T}^2)$$

f
∈

L
1

(

T

2

)

converge to

$$f$$

f

at each Lebesgue
point as

$$n\to \infty$$

n
→
∞

and n is in the cone around the graph of

$$\delta$$

δ

. We also prove this
result for higher dimensional functions and for other summability means. This is
a generalization of the classical one-dimensional Lebesgue’s theorem for the Fejér
means.
On product representations of squares
Authors: Tao T. 
Published: February 2025

Abstract
Fix

$$k \geq 2$$

k
≥
2

. For any

$$N \geq 1$$

N
≥
1

, let

$$F_k(N)$$

F
k

(
N
)

denote the cardinality of the largest subset of

$$\{1,\dots,N\}$$

{
1
,
⋯
,
N
}

that does not contain

$$k$$

k

distinct elements whose product is a square. Erdős, Sárközy, and Sós showed that

$$F_2(N) = (\frac{6}{\pi^2}+o(1)) N$$

F
2

(
N
)

=

(

6

π
2

+
o

(
1
)

)

N

,

$$F_3(N) = (1-o(1))N$$

F
3

(
N
)

=

(
1
-
o

(
1
)

)

N

,

$$F_k(N) \asymp N/\log N$$

F
k

(
N
)

≍
N
/
log
N

for even

$$k \geq 4$$

k
≥
4

, and

$$F_k(N) \asymp N$$

F
k

(
N
)

≍
N

for odd

$$k \geq 5$$

k
≥
5

. Erdős then asked whether

$$F_k(N) = (1-o(1)) N$$

F
k

(
N
)

=

(
1
-
o

(
1
)

)

N

for odd

$$k \geq 5$$

k
≥
5

. Using a probabilistic argument, we answer this question in the negative.
Cross-contextual stress prediction: Simple methodology for comparing features and sample domain adaptation techniques in vital sign analysis
Authors: Mihirette Samson , De la Cal Enrique A. , Tan Qing , Sedano Javier 
Published: February 2025

Abstract
Stress significantly impacts individuals, particularly in professions like nursing and driving, leading to severe health risks and accidents. Accurate stress measurement is critical for effective interventions, yet research is hindered by incomplete datasets and inconsistent methodologies, slowing the development of reliable predictive models. This paper introduces a framework for cross-contextual stress prediction, enabling the generation of general stress prediction models adaptable to specific domain challenges. The methodology leverages two general daily life datasets and three domain-specific datasets, employing steps such as dataset selection, feature extraction, significant feature identification, feature preprocessing, fine-tuning, domain adaptation, and application to specific contexts. Through this framework, key vital signs were identified as significant predictors of stress, including electrocardiography (ECG), heart rate (HR), heart rate variability (HRV) - low frequency (LF), electrodermal activity (EDA), body temperature (TEMP), and skin conductance response (SCR). The experiments conducted include: 1) Utilizing HR and HRV-LF through domain adaptation from general to automobile driving datasets; 2) Applying EDA, HR, and TEMP from general to specific nurse activity datasets; and 3) Adapting ECG, HR, and TEMP from general to automobile driving datasets. Results demonstrate the potential of the proposed framework for cross-contextual stress prediction, with HR and HRV-LF identified as pivotal features. When applied to target datasets specific to stress scenarios, the model achieved a 62% F1 score, demonstrating the effectiveness of the feature-based Correlation Alignment (CORAL) technique combined with Random Forest models in transferring learned knowledge across domains. These findings highlight the robustness of the approach in adapting general stress prediction models to specific contexts, paving the way for real-world applications such as stress monitoring in driving and nursing during high-stress periods like COVID-19.
Moisture and soil depth govern relationships between soil organic carbon and oxalate-extractable metals at the global scale
Authors: von Fromm Sophie F. , Jungkunst Hermann F. , Amenkhienan Bright , Hall Steven J. , Georgiou Katerina , Pries Caitlin Hicks , Montaño-López Fernando , Quesada Carlos Alberto , Rasmussen Craig , Schrumpf Marion , Singh Balwant , Thompson Aaron , Wagai Rota , Fiedler Sabine 
Published: February 2025

Abstract
An important control on long-term soil organic carbon (SOC) storage is the adsorption of SOC by short-range-ordered (SRO) minerals. SRO are commonly quantified by measuring oxalate-extractable metals (Mox = Alox + ½ Feox), which many studies have shown to be positively correlated with SOC. It remains uncertain if this organo-mineral relationship is robust at the global scale, or if capturing regional differences is needed to maximize model accuracy. We used a global synthesis of Alox and Feox data to test their role in controlling SOC abundance across regions. We compiled 37,344 individual soil horizon measurements, with soil depth ranging between 0 and 200 cm, from 11,122 profiles. We used the Holdridge Life Zones, which are characterized by biotemperature, precipitation, and potential evapotranspiration, to group the soil profiles by their climatic conditions that also correlate with other important soil-forming factors. Based on linear mixed-effects models, we found a positive relationship between Mox and SOC across regions and depths, accounting for 49% of the SOC variation. This relationship is strongest in wetter regions and at depths between 20 and 100 cm. Across all environmental conditions, Alox is a stronger predictor of SOC than Feox. Our analysis suggests oxalate-extractable metals are good proxies for mineral-induced SOC protection at the global scale. However, our findings also indicate that the importance of organo-mineral interactions at the global scale varies with climatic conditions and depth. The underlying mechanisms need to be considered when incorporating these relationships as proxies for mineral sorption capacity into soil C models.
Low molecular weight organic acids mobilize soil organic phosphorus for enzymatic hydrolysis in a temperate montane peatland
Authors: Suo Yuchen , Li Tong , von Sperber Christian , Ge Leming , Cao Chenhao , Zhai Zhifeng , Bu Zhaojun , Wang Meng 
Published: February 2025

Abstract
The stability of carbon (C) stocks in peatlands is intricately linked to phosphorus (P) bioavailability. Given that organic P compounds (Po) can make up to 89% of total soil P in these ecosystems, it is vital to understand their role in regulating plant productivity and organic matter decomposition. Despite this significance, the mechanisms controlling P bioavailability remain poorly understood. Plants and soil microorganisms primarily regulate the release of soil P via low-molecular-weight organic acids (LMWOAs) and modulate the hydrolysis of Po through phosphatase enzymes, particularly phosphomonoesterase, phytase, and phosphodiesterase. This study investigated the role of LMWOAs, derived from root exudates of dominant vascular plants and Sphagnum leachates in a temperate montane peatland, in facilitating the release of P. We also quantified the ability of these plants to hydrolyze Po from various LMWOA-extracted fractions by adding phosphomonoesterase, phytase, and phosphodiesterase. The results show that peatland plants predominantly exuded muconic, azelaic, 3-hydroxybutyric, and malonic acids. The concentration of enzymatically hydrolyzed Po in the water-extracted fraction was 8.1 ± 3.4 mg kg−1. Notably, azelaic and malonic acids were effective in releasing over 58% of soil P (330–798 mg kg−1), with more than 88% of this P being in organic form. In the azelaic and malonic acid-extracted fractions, the concentration of enzymatically hydrolyzed Po concentration was 123.7 ± 32.1 mg kg−1, accounting for 23% of the LMWOA-extracted Po. Phytase, the most important phosphatase enzyme, accounts for 66% (47–88%) of the enzymatically hydrolyzed Po (81.9 ± 20.9 mg kg−1). Our study demonstrates that LMWOA-mediated release of Po is an essential prerequisite for enzymatic hydrolysis of Po in organic peat soils. However, only a small portion of LMWOA-extracted Po can be hydrolyzed by phosphatase enzymes. The different composition and efficacy of LMWOAs from species of different plant functional types highlight the necessity to consider changes in vegetation composition, as this could significantly impact P dynamics in peatlands and, consequently, the stability of their C stocks.
Can “Fire Safe” Cigarettes (FSCs) Start Wildfires?
Authors: McAllister Sara , Williams Stephen , Grob Ian 
Published: February 2025

Abstract
Over the last 20 years, all states within the US have required all cigarettes sold to be “fire safe” or “fire standards compliant” meaning that they must pass ASTM standard E2187. Though these cigarettes are designed to self-extinguish, there have been recent studies suggesting that these “fire safe” cigarettes (FSCs) can still ignite mattresses and other furnishings, but there has been no guidance for fire investigators whether FSCs can ignite natural fuels, such as duff and needles, that can be the source of a wildland fire. This work sets out to investigate whether FSCs can indeed be the ignition source of wildland fuels. Experiments were conducted by placing “fire safe” cigarettes burned a fixed length (1 cm) onto fuel beds of two surrogate fuel types placed at the outlet of a wind tunnel and under a halogen lamp to mimic a sunny day. The fuel beds consisted of either a bed of partially chopped pine needles or a layer of whole needles on top of a layer of peat. Five replicates with three wind speeds were tested. Mass loss rates of the fuel beds were recorded, and the experiments documented using both a visual and infrared camera. In nearly every case, smoldering ignition was seen that sustained propagation and spread well away from the cigarette, even when the cigarette appeared to self-extinguish. These results clearly indicate that “fire safe” cigarettes can indeed still start wildland fires, particularly in dry and windy conditions.
Quintessence scalar field and cosmological constant: dynamics of a multi-component dark energy model
Authors: Sahoo Prasanta , Roy Nandan , Mondal Himadri Shekhar 
Published: February 2025

Abstract
This study explores the dynamics and phase-space behavior of a multi-component dark energy model, where the dark sector consists of a minimally coupled canonical scalar field and the cosmological constant, using a dynamical system analysis setup for various types of potential for which a general parameterization of the scalar field potentials has been considered. Several fixed points with different cosmological behaviors have been identified. A detailed stability analysis has been done and possible late-time attractors have been found. For this multi-component dark energy model, the late-time attractors are either fully dominated by the cosmological constant or represent a scenario where a combination of the scalar field and the cosmological constant dominates the universe. In this type of model, there is a possibility that the scalar field can become dynamical quite early compared to the standard era of dark energy domination. However, our analysis indicates that this early time contribution of the scalar field occurs deep in the matter-dominated era, not before the recombination era.
Integrating Practice-Based Activities and Visual Representations to Foster Students’ Understanding of Basic Astronomy Phenomena: An Example about Seasonal Changes
Authors: Galano Silvia , Testa Italo 
Published: February 2025

Abstract
This study investigates how different combinations of practice-based activities and visual representations affect students’ learning about seasonal changes. We adopted a pre-post 3 × 2 experimental design in which we first randomly assigned 12 intact 9th-grade classes (N = 337 students) to either a “practice-based activity” or a “no practice-based activity” and then to one of the following conditions: “specially designed images”; “textbook images”; “no images”. We used a draw-and-explain task and a mixed multiple-choice true/false questionnaire, the Seasons Concepts Inventory (SCI), to assess students’ conceptual understanding of seasons before and after participating to one of the teaching conditions. Data were analyzed using a 2-way between subjects factorial analysis of variance (ANOVA). The results indicate a significant interaction effect between the experimental conditions. Students in the “practice-based activity” condition outperformed students in the “no practice-based activity” condition, regardless of the type of image used. However, the students in the “specially designed images” condition performed significantly better than those in the “textbook images” and “no images” conditions in both the draw-and-explain task and the SCI instrument, regardless of the practice-based activity condition. Furthermore, the students in the “no practice-based activity” condition who were taught with the specially designed images did not perform significantly different from the students in the “practice-based activity” condition who were taught with the same types of images. Our study has implications for astronomy education practice in that it shows advantages and limitations of combining two approaches that are usually implemented separately. This study has also broader educational implications in that it demonstrates that when combining two different teaching approaches, the effectiveness of each approach may depend on the specific combination adopted.
Phycosphere of an algal co-culture phycoremediation system: Stability of bacterial communities in an Oedogonium-Stigeoclonium co-culture during cultivation in microbially rich wastewater
Authors: Wood Ethan , Edvardsen Bente , Skjånes Kari , Šupraha Luka 
Published: February 2025

Abstract
Algal-based wastewater remediation systems (phycoremediation) include phycosphere bacterial communities that influence algal growth, pollutant remediation, and downstream applications of biomass as fertilizers or bio-stimulants. This study investigated the bacterial community dynamics in a novel phycoremediation system using a co-culture of the green algae Stigeoclonium sp. and Oedogonium vaucheri. Bacterial abundance was estimated using flow cytometry (FCM), while community composition was assessed through 16S rRNA gene metabarcoding. Additionally, 28 bacterial strains were isolated from the bioremediation experiment, cultured, genetically characterized for identification and screened for production of the auxin phytohormone indole-3-acetic acid (IAA). Metabarcoding showed that the free-living bacterial community consisted of bacteria from both the wastewater effluent and the algal inocula, while the attached phycosphere community was dominated by bacteria from the algal inocula, indicating the stability of the algae-associated phycosphere. Taxa known to include plant growth-promoting bacteria (PGPB) were abundant, and several strains produced IAA. The bacterial community composition, combined with the potential production of phytohormone by isolated bacteria indicates symbiotic or commensal algae-microbe interactions within the phycosphere bacterial communities. Sterile filtration of wastewater effluent, including only the algal inoculum bacterial communities, reduced algal biomass production and increased bacterial abundance. This study highlights the critical role of microbial interactions in engineered ecosystems and provides insights for optimizing algal-based wastewater treatment technologies.
Personalized intraoperative arterial pressure management and mitochondrial oxygen tension in patients having major non-cardiac surgery: a pilot substudy of the IMPROVE trial
Authors: Flick Moritz , Vokuhl Christina , Bergholz Alina , Boutchkova Kristina , Nicklas Julia Y. , Saugel Bernd 
Published: February 2025

Abstract
The “Cellular Oxygen METabolism” (COMET) system (Photonics Healthcare, Utrecht, The Netherlands) non-invasively measures mitochondrial oxygen tension (mitoPO2) in the skin. The effects of general anesthesia and major non-cardiac surgery on mitoPO2 remain unknown. In this pre-planned pilot substudy of the “Intraoperative blood pressure Management based on the individual blood PRessure profile: impact on postOperatiVE organ function” (IMPROVE) trial, we measured mitoPO2 from induction of general anesthesia until the end of surgery in 19 major non-cardiac surgery patients (10 assigned to personalized and 9 to routine intraoperative arterial pressure management). In the overall cohort, the median (25th to 75th percentile) preoperative awake mitoPO2 was 63 (53 to 82) mmHg and mitoPO2 after induction of general anesthesia was 42 (35 to 59) mmHg. The intraoperative average mitoPO2 was 39 (30 to 50) mmHg. Thirteen patients (68%) had intraoperative mitoPO2 values below 20 mmHg and the median percentage of surgical time with mitoPO2 < 20 mmHg was 17 (0 to 31)%. MitoPO2 was weakly correlated with mean arterial pressure (repeated measures correlation (rrm(n); rrm(984) = 0.26, 95% confidence interval 0.20 to 0.32; P < 0.001), but not meaningfully with heart rate (rrm(984) = -0.05, 95% confidence interval -0.11 to 0.01; P = 0.117). There was no important difference in intraoperative average mitoPO2 between patients assigned to personalized or to routine intraoperative arterial pressure management (P = 0.653). MitoPO2 under general anesthesia was about a quarter lower than preoperative awake mitoPO2, substantially fluctuated during major non-cardiac surgery, and transiently decreased below 20 mmHg in about two-thirds of the patients. Personalized – compared to routine – intraoperative arterial pressure management did not increase intraoperative mitoPO2. Whether intraoperative decreases in mitoPO2 are clinically meaningful warrants further investigation.
Adolescent Domestic Abuse and Its Consequences: A Rapid Systematic Review
Authors: Weir Ruth , Adisa Olumide , Blom Niels , Hadjimatheou Katerina , Lamarre Flavia , Carlisle Sophie , Barrow-Grint Katy 
Published: February 2025

Abstract

Purpose
As a phenomenon, abusive behavior between adolescents in intimate relationships remains relatively invisible, due in part to the persistent yet unfounded assumption that domestic abuse is something that occurs between adults. This review investigates adolescent domestic abuse (ADA), by focusing on the impacts and risk factors for adolescents, particularly those under the age of 16, experiencing ADA.

Methods
We conducted a rapid systematic review by searching three electronic databases (PsycInfo, Embase, and Social Sciences Citation Index). We utilized pre-existing systematic reviews to identify relevant primary studies. Findings of the included studies were described and summarized using narrative synthesis.

Results
Seventy-nine studies were identified for inclusion. Synthesis of the findings of these studies identified five categories of risk and protective factors, including bullying and parental intimate partner violence, social and cultural factors, school and neighborhood environment and health and wellbeing. However, the review also identified a gap of qualitative research and a lack of attention to how ADA intersects with cultural factors, gender differences, criminalization, and poor mental health. Many of the studies report on school-based settings, limiting understanding of the role of neighborhood factors in prevention, protection and recovery. Participatory research on help-seeking behaviors of adolescents is rare.

Conclusions
The review synthesized risk and protective factors associated with ADA, especially those occurring between younger adolescents. It highlighted the complex interplay and overlap between using and experiencing violence and abuse and the need for systematic research to inform the development of advocacy, interventions and prevention that is right for young people.
A Proximal-Type Method for Nonsmooth and Nonconvex Constrained Minimization Problems
Authors: Sempere Gregorio M. , de Oliveira Welington , Royset Johannes O. 
Published: February 2025

Abstract
This work proposes an implementable proximal-type method for a broad class of optimization problems involving nonsmooth and nonconvex objective and constraint functions. In contrast to existing methods that rely on an ad hoc model approximating the nonconvex functions, our approach can work with a nonconvex model constructed by the pointwise minimum of finitely many convex models. The latter can be chosen with reasonable flexibility to better fit the underlying functions’ structure. We provide a unifying framework and analysis covering several subclasses of composite optimization problems and show that our method computes points satisfying certain necessary optimality conditions, which we will call model criticality. Depending on the specific model being used, our general concept of criticality boils down to standard necessary optimality conditions. Numerical experiments on some stochastic reliability-based optimization problems illustrate the practical performance of the method.
Patient Experiences of a Postpartum Cardiovascular Disease Intervention Clinic for Pregnancy Complications
Authors: Manthorpe Tegan , Arstall Margaret , Andraweera Prabha H. , Aldridge Emily 
Published: February 2025

Abstract

Objectives
Experiencing a maternal complication of pregnancy conveys a significantly higher risk of developing premature cardiovascular disease compared to having an uncomplicated pregnancy. Postpartum interventions that aim to improve lifestyle and modifiable risk factors for people in this cohort may reduce cardiovascular disease risk. This study will explore the experiences and barriers to attendance of patients referred to one such clinic located in South Australia.

Methods
This qualitative study conducted six focus groups comprised of two-six patients who had attended at least one postpartum intervention clinic appointment (N = 19). Audio recordings were captured and transcribed and NVivo was used to perform a thematic analysis.

Results
Participants found the clinic informative as it educated them on their greater risk of cardiovascular disease and how to reduce this risk. They reported wanting more frequent appointments and the ability to opt in for additional contact, including newsletters and social media groups. We also identified several barriers to attendance, including an unclear clinic referral and appointment booking process, and missing clinic correspondence including appointment letters and pathology forms.

Conclusions for Practice
This study provides insight into the experiences of patients who attended a postpartum cardiovascular disease prevention clinic. The clinic model can be operated in different health care settings to become part of standardized care in the postpartum period for patients who have had a pregnancy complication. Refinement of the clinic model referral and booking processes could reduce potential barriers to patient attendance.