bluuebunny/crossref_metadata_2025 huggingface dataset:
Semi-continuous cultivation for enhanced protein production using indigenous green microalgae and synthetic municipal wastewater
Authors: Umetani Ikumi , Sposób Michał , Tiron Olga
Published: January 2024

Cultivation of microalgae has gained significant interest as an alternative protein source, potentially becoming a target commodity recovered from microalgae-based wastewater treatment. This study examined a semi-continuous cultivation strategy to optimize protein accumulation of the indigenous freshwater chlorophytes, Lobochlamys segnis and Klebsormidium flaccidum, and simultaneously remove nutrients from wastewater efficiently. A strain-specific regime was made based on a fixed biomass concentration at the start of 24-h cultivation cycle, i.e., a constant initial cell density, which regulated harvesting and fresh medium supply volume according to the dilution rate. Six cultivation cycles were conducted in lab-scale 1L reactors with a synthetic municipal wastewater. Lobochlamys segnis and K. flaccidum grew exponentially in all cycles. The biomass productivity was 573 and 580 mg L–1 day–1, in which the total protein consisted of 62 and 45% of dry cell weight (dw), respectively. When a culture medium deficient in nitrogen and phosphorus was used, protein level was significantly reduced. L. segnis consumed all NH4+ and PO43– supplied by the medium replacement, giving the removal rate of 9.2 and 5.2 mg L–1 day–1. Whereas K. flaccidum removed 13.8 mg L–1 day–1 NH4+ without completing PO43– removal. The amino acid profile of both strains was characterized by glutamic acids content (4–5% dw). We concluded that the designed cultivation regime would support a constant biomass production with stable and high protein content, along with an efficient removal of nutrient from the wastewater.
A Hebrew Fragment in the Municipal Archive in Münster as a Witness to a Little-Known Ritual Practice
Authors: Kanarfogel Ephraim , Kogman-Appel Katrin
Published: January 2024

The Stadtarchiv in Münster, Germany holds a medieval Hebrew fragment with portions of the daily Shema Yisrael prayer. Measuring 510 mm in height, this fragment is but a quarter of a large-sized parchment sheet, which was designed to be hung on a wall. This study introduces the fragment and describes its material features and then suggests its possible function against the backdrop of talmudic discussions on biblical texts that are incorporated in prayer. In light of the halakhic position that biblical verses should not be recited from memory but only from a written text, the original sheet was intended to provide worshippers with an accessible copy of the Shema text, since many did not have personal prayerbooks.
Source parameters and scaling relationships of stress drop for shallow crustal seismic events in Western Europe
Authors: Yen Ming-Hsuan , Bindi Dino , Oth Adrien , Edwards Ben , Zaccarelli Riccardo , Cotton Fabrice
Published: January 2024

For an ω2-source model, moment-based estimates of the stress drop are obtained by combining corner frequency and seismic moment source parameters. Therefore, the moment-based estimates of the stress drop are informative about the amount of energy radiated at high frequencies by dynamic rupture processes. This study aims to systematically estimate such stress drop from the harmonized dataset at the European scale and to characterize the distributions of the stress drop for application in future stochastic simulations. We analyze the seismological records associated with shallow crustal seismic events that occurred in Western Europe between January 1990 and May 2020. We processed 220,000 high-quality records and isolated the contributions of the source, site, and path contributions using the Generalized Inversion Technique. The source parameters, including the corner frequency, moment magnitude, and stress drop, of 6135 seismic events are calculated. The events processed are mainly tectonic events (e.g., earthquakes of the central Italy 2009–2016 sequence), although non-tectonic events associated with the Groningen gas field and mining activities in Western Europe are also included in the analysis. The impact of different attenuation models and reference site choices are evaluated. Most of the obtained source spectra follow the standard ω2-model except for a few events where the data sampling considered does not allow an effective spectral decomposition. The resulting stress drop shows a positive correlation with moment magnitude between 3 and 4, and a self-similarity for magnitudes greater than 4 with a mean stress drop of 13.8 MPa.
Designing hardware for a robust high-speed cryptographic key generator based on multiple chaotic systems and its FPGA implementation for real-time video encryption
Authors: İnce Esra , Karakaya Barış , Türk Mustafa
Published: January 2024

Recent advancements in communication technologies have highlighted the pivotal role of information security for all individuals and entities. In response, researchers are increasingly focusing on cryptographic solutions to ensure the reliability of confidential information. Recognizing the superiority of chaotic systems preference as entropy source of cryptographic systems, this paper proposes a novel true random number generator (TRNG) design by combining four different chaotic systems outputs, tailored for real-time video encryption application. These chaotic systems are continuous-time Lorenz and fractional-order Chen-Lee systems, as well as discrete-time Logistic and Tent maps. This study generates true random bit (TRB) sequences at a high bit rate (25 Mbps) through the hardware implementations of four distinct chaotic systems to have the best statistical randomness in the resulting output. Then, the cryptographic true random key bits (8-bit at 25 MHz frequency) are employed in the post-processing with real-time video data by using the XOR operation, a fundamental post-processing algorithm. The real-time video encryption application is executed on an experimental assembly, composed of a Field Programmable Gate Array (FPGA) development kit, an OV7670 camera module, a VGA monitor, and prototype circuit boards for the chaotic systems. To evaluate the effectiveness of the proposed encryption system, several security assessments are conducted. These include NIST SP 800 − 22 statistical tests, FIPS 140-1 standards, chi-square tests, histogram and correlation analysis, and NPCR and UACI differential attack resilience tests. Consequently, the findings suggest that the presented real-time embedded cryptosystem is robust and suitable for secure communications, particularly in the realm of video transmission.
Vital signs estimation in elderly using camera-based photoplethysmography
Authors: Caroppo Andrea , Manni Andrea , Rescio Gabriele , Siciliano Pietro , Leone Alessandro
Published: January 2024

In the context of Ambient Assisted Living, the demand for healthcare technologies development has been increased in the last two years by the current global health situation. The contagious nature of COVID-19 warrants inevitability to the thought of easing a continuous measurement of vital signs such as Heart Rate, Breath Rate, and SpO2 in a non-invasive manner, contributing of fundamental importance in the assessment of health status especially among frail and/or elderly individuals. A widely diffused method for contactless vital signs monitoring is remote photoplethysmography from facial video streams that, contrary to traditional contact measurement techniques, allows the measurement of vital parameters without the need for wearable sensors (generally considered uncomfortable, especially by the elderly), even with commercial and low-cost digital cameras. This paper proposes the design and implementation of a new pipeline for estimating Heart Rate, Breath Rate, and SpO2 values, and its integration on Raspberry Pi 4 as an elaboration unit. The pipeline provides specific algorithmic blocks to improve vital signs estimation in elderly subjects as it is made more difficult by the skin tone and the presence on the face of wrinkles, folds, and moles. Quantitative evaluations on our dataset containing the acquisition of only elderly older than 65 years of age demonstrate the validity of the proposed pipeline. For validation against the state of the art, tests were also conducted on three standard benchmark datasets containing video with subjects of varying ages. Again, the pipeline proved to be robust concerning the estimation of vital signs considered in the present work.
Predefined-time VFO control design for unicycle-like mobile robots
Authors: Sobański Rafał M. , Michałek Maciej M. , Defoort Michael
Published: January 2024

The paper presents a predefined-time Vector-Field-Orientation (VFO) control law for unicycle-like nonholonomic mobile robots. We consider a set-point control problem in the presence of strict time constraints, which has to guarantee satisfaction of a prescribed upper bound of the settling time for the configuration errors. The control law is based on the VFO methodology, which is characterized by non-oscillatory and well-predictable time evolution of transient states for unicycle-like robots. A formal stability analysis based on the Lyapunov theory is provided for the closed-loop dynamics. Then, the results of extensive numerical simulations as well as experimental tests illustrate the resultant control performance where time constraints are considered. The proposed approach is compared with an alternative predefined-time stabilizer, recently introduced for nonholonomic chained-form systems.
The impact of sucrose and 6-benzylaminopurine on shoot propagation and vitrification in Aronia melanocarpa (black chokeberry)
Authors: Bayhan Nida , Yücesan Buhara
Published: January 2024

Vitrification is one of the most significant issues encountered in plant tissue culture applications. It diminishes the quality of in vitro plants, causing their leaves and stems to appear watery and translucent, and it may impede the success of the acclimatization step. In this respect, this study investigates the impact of sucrose and 6-Benzylaminopurine (BAP) concentrations on shoot regeneration and vitrification development in Aronia melanocarpa, known for its high antioxidant content and health benefits. Initially, the presence of BAP, in combination with varying sucrose concentrations, leads to a substantial increase in shoot number, and the largest number (7 shoots per nodal explant) was observed in the Murashige and Skoog (MS) medium containing 3% sucrose and 5.0 mg/L BAP. Furthermore, sucrose concentration plays a crucial role in shoot growth, with higher concentrations promoting more extensive shoot development. However, when 3% sucrose was combined with higher BAP (from 1.0- to 5.0 mg/L), an increased incidence of vitrification was observed over time. Interestingly, lower sucrose concentrations (1% or 2%) combined with 0.5 mg/L or 2.5 mg/L BAP initially delayed vitrification but eventually led to its occurrence. Microscopic analysis of leaf samples with varying levels of vitrification indicates significant differences in the density of stomata, further confirming the detrimental impact of vitrification on cellular structures and physiological processes. The recovery of vitrified plants was evaluated using different growth media combinations. The absence of BAP in the medium led to higher recovery percentages (min 96%) without necrosis, while the addition of 0.5 mg/L BAP promoted shoot growth but potentially inhibited root development. It has been found that media with 1 mg/L BAP and either 10 g/L or 20 g/L sucrose, as well as media with 30 g/L sucrose and 0.5 mg/L BAP, are the most suitable for efficient shoot regeneration with minimal vitrification risk. However, increasing BAP levels for faster shoot regeneration also raises the risk of vitrification. During acclimatization, vitrified plants exhibited stunted shoot growth, shorter and narrower leaves, reduced root numbers and lengths, and decreased survival rates, particularly under lower humidity conditions. The cultivation period required for the recovery of the crop was determined to be 6 weeks under greenhouse conditions for a sustainable plant propagation.
Optimization of Process Parameters Affecting Glycoalkaloids in Potato Chips Using the Taguchi Method
Authors: Koyuncu Dilek , Duran Ayhan
Published: January 2024

This study presents the experimental and statistical examination of different process applications in the production process of the glycoalkaloid level in potato chips to which consumers are exposed. In the first stage, slice washing temperature (swt), frying temperature (ftemp) and frying time (ft) were determined as factors that could affect the glycoalkaloid level. Considering industrial applications, three different slice washing temperatures (25, 55 and 85 °C), frying temperatures (180, 185 and 190 °C) and frying times (165, 185 and 205 s) were evaluated for the study. The L9 orthogonal array of the Taguchi method, which has been successfully applied in the analysis of multiple parameters, was used as the experimental design. Examining the S/N (signal/noise) ratios, the optimum process parameters for minimum content of α-solanine (As) were obtained as 25 °C swt, 190 °C ftemp and 165 s ft. The optimum process parameters were determined for minimum content of α-chaconine (Ac) as 55 °C swt, 190 °C ftemp and 165 s ft. In the analysis results, as swt decreased, ftemp increased, and ft was shortened; the glycoalkaloid ratio in the chips decreased. Analysis of variance results showed the most effective process parameter was the frying time for α-solanine and α-chaconine with 68.2% and 76.5%, respectively. Then comes ftemp with an effectiveness rate of 17.35% and 16.77%. In addition, the regression model developed to estimate the output parameters (As and Ac) yielded successful results with high determination coefficients (R2) of 90.6% and 92.5%.
Bariatric Surgery and Weight Gain: Bibliometric Analysis
Authors: Seckin Damla , Cebeci Fatma
Published: January 2024

Purpose

Bariatric surgery is the most successful method for weight loss; however, weight regain may occur in the long term. It depends on eating habits and self-management. The study aimed to conduct a bibliometric analysis on bariatric surgery and weight gain and to determine the content and trends in the literature.

Materials and Methods

The scan was performed using the keywords “bariatric surgery” and “weight gain” in the Web of Science database. The years of publications and citations, the distribution of publications according to journals, research areas, and countries, co-authorship, co-occurrence, and co-citation were analyzed. The VOSviewer program was used for the analysis. Grey literature, books, and book sections were not included.

Results

A total of 988 articles were included. The results showed that the most published and cited journal was Obesity Surgery, and the most published country was the USA with 313 publications. The most commonly used keywords were “bariatric surgery,” “obesity,” and “weight regain.” Harvard University was the most publishing institution with 50 publications. The most published year was 2022 since 1993 (n:118).

Conclusion

In the study, current publications and research trends related to bariatric surgery and weight gain were analyzed through bibliometric analysis. It was concluded that weight regain after bariatric surgery should be focused on since it adversely affects the life of individuals, reduces the probability of success of surgical treatment, and imposes additional burdens on the healthcare system.

Graphical Abstract
Electronic sanitary database: a new potential tool to identify occult chronic liver disease in general population
Authors: Cagnin Silvia , Martini Andrea , Donato Daniele , Angeli Paolo , Pontisso Patrizia
Published: January 2024

Chronic liver disease (CLD) is a leading global cause of mortality, morbidity, and healthcare resource utilization. However, the burden of CLD is underestimated because the course of the disease is often asymptomatic until clinical decompensation and the development of life-threatening complications. In this study, we assessed the use of available blood tests from electronic medical records for identifying individuals with undiagnosed CLD in the general population. We analyzed a total of 202,529 blood tests obtained from 99,848 adults recorded in the Electronic Health Records of the Padova Teaching Hospital. Transaminases levels > 1.5 times the normal value indicated occult CLD, while platelet counts < 120,000/μL identified occult cirrhosis. We characterized patients using Italian Medical Exemptions (IME), excluding oncologic cases. Overt and occult cirrhosis prevalence was 1% and 4.18%, respectively, while overt and occult CLD affected 2.85% and 4.61% of the population. The epidemiology of patients with overt and occult cirrhosis was similar but significantly different from that of the controls. Among subjects aged 60–70 years, working disability was twofold higher in those with occult cirrhosis compared to those with overt cirrhosis. Occult CLD and cirrhosis had higher prevalence rates than diagnosed cases in the general population. Electronic medical record data may serve as a valuable tool for CLD identification, potentially reducing cirrhosis development and clinical decompensation. This, in turn, may lead to a decrease in the economic impact on the healthcare system.
Optimal semiclassical spectral asymptotics for differential operators with non-smooth coefficients
Authors: Mikkelsen Søren
Published: January 2024

We consider differential operators defined as Friedrichs extensions of quadratic forms with non-smooth coefficients. We prove a two-term optimal asymptotic for the Riesz means of these operators and thereby also reprove an optimal Weyl law under certain regularity conditions. The methods used are then extended to consider more general admissible operators perturbed by a rough differential operator and to obtain optimal spectral asymptotics again under certain regularity conditions. For the Weyl law, we assume that the coefficients are differentiable with Hölder continuous derivatives, while for the Riesz means we assume that the coefficients are twice differentiable with Hölder continuous derivatives.
The Use of Artificial Intelligence in Writing Scientific Review Articles
Authors: Kacena Melissa A. , Plotkin Lilian I. , Fehrenbacher Jill C.
Published: January 2024

Purpose of Review

With the recent explosion in the use of artificial intelligence (AI) and specifically ChatGPT, we sought to determine whether ChatGPT could be used to assist in writing credible, peer-reviewed, scientific review articles. We also sought to assess, in a scientific study, the advantages and limitations of using ChatGPT for this purpose. To accomplish this, 3 topics of importance in musculoskeletal research were selected: (1) the intersection of Alzheimer’s disease and bone; (2) the neural regulation of fracture healing; and (3) COVID-19 and musculoskeletal health. For each of these topics, 3 approaches to write manuscript drafts were undertaken: (1) human only; (2) ChatGPT only (AI-only); and (3) combination approach of #1 and #2 (AI-assisted). Articles were extensively fact checked and edited to ensure scientific quality, resulting in final manuscripts that were significantly different from the original drafts. Numerous parameters were measured throughout the process to quantitate advantages and disadvantages of approaches.

Recent Findings

Overall, use of AI decreased the time spent to write the review article, but required more extensive fact checking. With the AI-only approach, up to 70% of the references cited were found to be inaccurate. Interestingly, the AI-assisted approach resulted in the highest similarity indices suggesting a higher likelihood of plagiarism. Finally, although the technology is rapidly changing, at the time of study, ChatGPT 4.0 had a cutoff date of September 2021 rendering identification of recent articles impossible. Therefore, all literature published past the cutoff date was manually provided to ChatGPT, rendering approaches #2 and #3 identical for contemporary citations. As a result, for the COVID-19 and musculoskeletal health topic, approach #2 was abandoned midstream due to the extensive overlap with approach #3.

The main objective of this scientific study was to see whether AI could be used in a scientifically appropriate manner to improve the scientific writing process. Indeed, AI reduced the time for writing but had significant inaccuracies. The latter necessitates that AI cannot currently be used alone but could be used with careful oversight by humans to assist in writing scientific review articles.
Water Loss: A Postharvest Quality Marker in Apple Storage
Authors: Hasan Mahmood Ul , Singh Zora , Shah Hafiz Muhammad Shoaib , Kaur Jashanpreet , Woodward Andrew
Published: January 2024

Apple fruit can be stored for long periods of time, especially with the use of controlled atmosphere storage, but like many fruits and vegetables are susceptible to water loss. Water loss can result in compromised appearance such as skin shriveling, as well as loss of firmness, and reduced saleable weight, which in turn affect the income of growers and other industry stakeholders. Preharvest factors that can influence water loss in apples during the postharvest period include climate, cultivar, fruit size, tree age, orchard practices, and harvest maturity. Postharvest factors such as the storage temperature, relative humidity, storage type, and duration can also affect water loss in apple fruit during storage. The mechanisms of cuticle biosynthesis in water permeance, the role of stomata and lenticels, microcracking, crosstalk with mechanical injuries, storage disorders, and decay incidence during the storage of apples are reviewed. Additionally, the review summarizes: preharvest and postharvest factors influencing water loss; recent management strategies including pre-cooling, cold storage, controlled atmospheres, packaging, and anti-senescence chemicals; the use of edible coatings, as well as other non-chemical approaches for modulating water loss and maintaining storage quality. The review also provides direction for the industry to manage this destructive problem in the postharvest supply chain of apple fruit.
Energy Stability for a Class of Semilinear Elliptic Problems
Authors: Afonso Danilo Gregorin , Iacopetti Alessandro , Pacella Filomena
Published: January 2024

In this paper, we consider semilinear elliptic problems in a bounded domain$$\Omega $$Ωcontained in a given unbounded Lipschitz domain$${\mathcal {C}} \subset {\mathbb {R}}^N$$C⊂RN. Our aim is to study how the energy of a solution behaves with respect to volume-preserving variations of the domain$$\Omega $$Ωinside$${\mathcal {C}}$$C. Once a rigorous variational approach to this question is set, we focus on the cases when$${\mathcal {C}}$$Cis a cone or a cylinder and we consider spherical sectors and radial solutions or bounded cylinders and special one-dimensional solutions, respectively. In these cases, we show both stability and instability results, which have connections with related overdetermined problems.
Efficacy and Acceptance of Cognitive Behavioral Therapy in Adults with Chronic Fatigue Syndrome: A Meta-analysis
Authors: Maas genannt Bermpohl Frederic , Kucharczyk-Bodenburg Ann-Cathrin , Martin Alexandra
Published: January 2024

Background

The systematic aggregation of research on cognitive behavioral therapy (CBT) in chronic fatigue syndrome (CFS) needs an update. Although meta-analyses evaluating interventions typically focus on symptom reduction, they should also consider indicators of treatment acceptability, e.g., drop-out rates.

Methods

Randomized controlled trials (RCTs) investigating CBT in adults with CFS compared to inactive and non-specific control groups were included. First, efficacy was examined, considering fatigue, depression, anxiety, and perceived health. Secondly, drop-out rates through different trial stages were analyzed: Non-completion of all mandatory sessions, drop-out (primary study definition), treatment refusal (non-starters), and average of sessions completed.

Result

We included 15 RCTs with 2015 participants. CBT was more effective than controls in fatigue (g = -0.52, 95%CI -0.69 to -0.35), perceived health, depression, and anxiety at post-treatment. At long-term follow-up the effects were maintained for fatigue and anxiety. Rates of non-completion (22%, 95%CI 3–71), drop-out (15%, 95%CI 9–25), and treatment refusal (7%, 95%CI 3–15) were relatively low, with a high average proportion of sessions completed. Total time of therapy moderated the effect on fatigue, while the number of sessions moderated the effect on perceived health. Fatigue severity influenced adherence.

Conclusion

The results indicate that CBT for CFS is effective in reducing fatigue, fatigue related impairment, and severity of depression and anxiety. Conclusions on efficacy at follow-ups are still limited. However, adherence is high in CBT. The results may help to inform clinical practice. Future research should focus on examining the maintenance of effects, while also emphasizing the importance of treatment acceptance.
Genomic and transcriptomic profiling of hepatocellular carcinoma reveals a rare molecular subtype
Authors: Zhu Mengting , Rovella Valentina , Scimeca Manuel , Mauriello Alessandro , Shi Yufang , Bischof Julia , Woodsmith Jonathan , Anselmo Alessandro , Melino Gerry , Tisone Giuseppe , Agostini Massimiliano
Published: January 2024

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide, occurring predominantly in patients with underlying chronic liver disease and cirrhosis. Here, we describe a case of a 62-year-old man that was admitted to our hospital and diagnosed with HCC where the cancer has already metastasized to the retroperitoneum and peritoneum. In order to better characterize the HCC, both the cancerous liver tissue and the adjacent normal liver tissue of the patient were collected and subjected to a genomic, transcriptomic and proteomic analysis. Our patient carries a highly mutated HCC, which is characterized by both somatic mutation in the following genes ALK, CDK6, TP53, PGR. In addition, we observe several molecular alterations that are associated with potential therapy resistance, for example the expression of the organic-anion-transporting polypeptide (OATP) family members B1 and B3, that mediate the transport of the anticancer drugs, has been found decreased. Overall, our molecular profiling potentially classify the patient with poor prognosis and possibly displaying resistance to pharmacological therapy.
Potential dosimetric error in the adaptive workflow of a 1.5 T MR-Linac from patient movement relative to immobilisation systems
Authors: Liu Min , Tang Bin , Orlandini Lucia Clara , Li Jie , Wang Xianliang , Peng Qian , Thwaites David
Published: January 2024

In magnetic resonance- (MR-) based adaptive workflows for an MR-linac, the treatment plan is optimized and recalculated online using the daily MR images. The Unity MR-linac is supplied with a patient positioning device (ppd) using pelvic and abdomen thermoplastic masks attached to a board with high-density components. This study highlights the dosimetric effect of using this in such workflows when there are relative patient-ppd displacements, as these are not visualized on MR imaging and the treatment planning system assumes the patient is fixed relative to the ppd. The online adapted plans of two example rectum cancer patients treated at a Unity MR-linac were perturbed by introducing relative patient-ppd displacements, and the effect was evaluated on plan dosimetry. Forty-eight perturbed clinical adapted plans were recalculated, based on online MR-based synthetic computed tomography, and compared with the original plans, using dose-volume histogram parameters and gamma analysis. The target volume covered by the prescribed dose ($${\text{D}}_{\text{p}\text{r}\text{e}}$$

D
pre

) and by at least 107% of $${\text{D}}_{\text{p}\text{r}\text{e}}$$

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varied up to − 1.87% and + 3.67%, respectively for 0.5 cm displacements, and to − 3.18% and + 4.96% for 2 cm displacements; whilst 2%–2 mm gamma analysis showed a median value of 92.9%. The use of a patient positioning system with high-density components in a Unity MR-based online adaptive treatment workflow can introduce unrecognized errors in plan dosimetry and it is recommended not to use such a device for such treatments, without modifying the device and the workflow, followed by careful clinical evaluation, or alternatively to use other immobilization methods.
A model for problem creation: implications for teacher training
Authors: Burgos María , Tizón-Escamilla Nicolás , Chaverri Jorhan
Published: January 2024

The invention of problems is a fundamental competence that enhances the didactic-mathematical knowledge of mathematics teachers and therefore should be an objective in teacher training plans. In this paper, we revise different proposals for categorizing problem-creation activities and propose a theoretical model for problem posing that, based on the assumptions of the Onto-Semiotic Approach, considers both the elements that characterize a problem and a categorization of different types of problem-posing tasks. In addition, the model proposes a description of the mathematical processes that occur during the sequence of actions carried out when a new problem is created. The model is illustrated by its application to analyze the practices developed by pre-service teachers in three problem-posing tasks aimed at specific didactic-mathematical purposes (mobilizing certain mathematical knowledge or reasoning, contributing to achieving learning goals, or addressing students’ difficulties). We conclude discussing the potential of our model to analyze the mathematical processes involved in problem creation from the perspective of teacher education.
On structures of normal forms of complex points of small $${\mathcal {C}}^{2}$$-perturbations of real 4-manifolds embedded in a complex 3-manifold
Authors: Starčič Tadej
Published: January 2024

We extend our previous result on the behaviour of the quadratic part of a complex points of a small $${\mathcal {C}}^{2}$$

C

2

-perturbation of a real 4-manifold embedded in a complex 3-manifold. We describe the change of the structure of the quadratic normal form of a complex point. It is an immediate consequence of a theorem clarifying how small perturbations can change the bundle of a pair of one arbitrary and one symmetric $$2\times 2$$

2
×
2

matrix with respect to an action of a certain linear group.
The isomorphism problem for basic modules and the divisibility profile of the algebra of polynomials
Authors: Aydoğdu P. , Arellano C. A. , López-Permouth S. R. , Muhammad R. , Zailaee M.
Published: January 2024

While mutual congeniality of bases is known to guarantee that basic modules from so-related bases are isomorphic, the question of what can be said about isomorphism of basic modules in general has remained open. We show that, for some algebras, basic modules may be non-isomorphic. We also show that it is possible, for some algebras, for all basic modules to be isomorphic, regardless of congeniality. In the process, and as a byproduct, we introduce the notion of domains of divisibility of modules over arbitrary rings. The mechanism employed here to differentiate non-isomorphic basic modules is by showing that they have different domains of divisibility. Domains of divisibility measure how divisible a module can be; for those cases when divisibility is equivalent to injectivity, domains of divisibility provide a way to gauge injectivity of modules as an alternative to the domains of injectivity and other mechanisms in the literature. We focus on the algebra of polynomials with one variable, and observe that F[x] has a full divisibility profile for any field F. When F is algebraically closed, we see that the direct product and the direct sum of all Pascal basic modules have the smallest divisibility domain. We also analyze the diversity of the family of basic modules as we explore how many of those divisibility domains correspond to basic modules. We show that, for an arbitrary infinite field F, F[x] has infinitely many pairwise non-isomorphic basic modules, the divisibility profile of F[x] is complete, and for an algebraically closed field F, the collection of basic modules has any subset S of F with a non-empty at most countable complement, the set $$\{ x + \alpha | \alpha \notin S \}$$

{
x
+
α
|
α
∉
S
}

as a domain of divisibility for some basic F[x]-module.
Techno-economic analysis of production of octane booster components derived from lignin
Authors: Ng Zi Wei , Yeoh King Yee , Hafyan Rendra Hakim , Putranto Aditya , Horri Bahman Amini , Zein Sharif H. , Rhamdhani MAkbar , Aziz Muhammad , Butar Ivan
Published: January 2024

In this study, a comprehensive process for production of an environmentally friendly octane booster (acetophenone) from lignin is presented, along with a detailed techno-economic analysis. Recognizing that much of the prior research on octane boosters has been confined to experimental lab-level investigations, this study develops comprehensive process design to unravel the intricacies of large-scale acetophenone production. The acetophenone production process involves catalytic hydrogenolysis, which also yields phenol as a valuable side product. Based on the process flow diagram, mass and energy balances were developed, revealing significantly improved yields and purity of acetophenone compared to industry standards, reaching 0.74 kg acetophenone per kg of lignin and 99 wt%. In the techno-economic analysis, calculations involving fixed capital investment (FCI), operating costs, and working capital were conducted based on a feed of 100 kg/h of dry lignin. The results indicate FCI at 2.72 million USD, operating costs at 1.09 million USD per year, and working capital at 0.57 million USD. Assuming a 20-year operational lifespan, the payback period is estimated at 6.09 years, as depicted by the cumulative cash flow diagram. Moreover, techno-economic analysis demonstrates a net present value (NPV) of 3.24 million USD at a 10% discount rate, an internal rate of return (IRR) of 22.73%, and a return on investment (ROI) of 34.39%. These positive outcomes underscore the robust profitability of the proposed acetophenone production plant derived from lignin. Additionally, a sensitivity analysis on the IRR indicates that increasing the production capacity could further enhance profitability, reaffirming the feasibility of the plant’s operation. Crucially, this study highlights the potential for sustainable and economically viable production of acetophenone, offering an environmentally friendly alternative to toxic octane boosters and advancing the development of sustainable fuel additives.

Graphical Abstract
Evolution of tribo-magnetization during sliding of ferromagnetic materials
Authors: Gao Fumin , Zhang Laibin , Zhou Jin , Xiong Yi , Wu Jing , Fan Jianchun
Published: January 2024

Sliding-induced subsurface microstructure evolution is believed to be decisive for determining the friction and wear performance of metallic contacts as well as the development of tribo-magnetization. This expects to develop a new prediction method of wear state by elucidating the correlation between subsurface microstructure evolution and corresponding magnetic domain changes. Herein, subsurface microstructure evolution including crystal and magnetic domain under tribological action is investigated experimentally. Our results demonstrate that dislocation mediated plastic deformation decisively influences microstructural changes during tribological contact, further determining the magnetic domain structure. Specifically, sliding-induced plastic deformation causes an increase in the width of magnetic domains, but depth-dependent derived microstructure formed under severe plastic deformation such as the refined grains and sub-grains, in turn, promoted the refinement of magnetic domains and their discontinuity, forming depth-dependent magnetic domain structure. These results are helpful to clarify the evolution of tribo-magnetization and the pinning effect of dislocations on magnetic domains.
Experimental study on the feasibility of alternative materials for tilting pad thrust bearings operating in transition to mixed friction
Authors: Wasilczuk Michał , Wodtke Michał
Published: January 2024

In hydrodynamic bearings traditional bearing alloys: Babbitts and bronzes are most frequently utilized. Polymer sliding layers are sometimes applied as a valuable alternative. Hard diamond-like carbon (DLC) coatings, which are also considered for certain applications may show some advantages, as well. Although material selection is of secondary importance in a full film lubrication regime it becomes important in mixed friction conditions, which is crucial for bearings with frequent starts and stops. Experimental research aimed at studying the performance of fluid film bearings in the specific operating regime, including the transition to mixed friction, is described in the paper. The tests were carried out on four tilting pad bearings of different material compositions: Steel/bronze, DLC/steel, steel/polyether ether ketone (PEEK), and steel/Babbitt. The tests comprised stopping under load and reproduction of the Stribeck curve by decreasing rotational speed to very low values, and observing the changes of friction force during the transition to mixed friction regime. Analysis of the transition conditions and other results showed clear differences between the tested bearings, illustrating the feasibility of less popular material compositions for bearings operating in specific conditions. More specifically, the DLC/steel bearing was demonstrating superior performance, i.e. lower friction, transition to mixed friction occurring at higher load, and more stable performance at start-stop regime over the other tested bearings.
Strain-Induced Surface Interface Dual Polarization Constructs PML-Cu/Bi12O17Br2 High-Density Active Sites for CO2 Photoreduction
Authors: Zhang Yi , Guo Fangyu , Di Jun , Wang Keke , Li Molly Meng-Jung , Dai Jiayu , She Yuanbin , Xia Jiexiang , Li Huaming
Published: January 2024

The insufficient active sites and slow interfacial charge transfer of photocatalysts restrict the efficiency of CO2 photoreduction. The synchronized modulation of the above key issues is demanding and challenging. Herein, strain-induced strategy is developed to construct the Bi–O-bonded interface in Cu porphyrin-based monoatomic layer (PML-Cu) and Bi12O17Br2 (BOB), which triggers the surface interface dual polarization of PML-Cu/BOB (PBOB). In this multi-step polarization, the built-in electric field formed between the interfaces induces the electron transfer from conduction band (CB) of BOB to CB of PML-Cu and suppresses its reverse migration. Moreover, the surface polarization of PML-Cu further promotes the electron converge in Cu atoms. The introduction of PML-Cu endows a high density of dispersed Cu active sites on the surface of PBOB, significantly promoting the adsorption and activation of CO2 and CO desorption. The conversion rate of CO2 photoreduction to CO for PBOB can reach 584.3 μmol g−1, which is 7.83 times higher than BOB and 20.01 times than PML-Cu. This work offers valuable insights into multi-step polarization regulation and active site design for catalysts.
Longitudinal Negotiation, Navigation Processes, and School Success in High School: A Two-Wave Latent Transition Approach
Authors: Kassis Wassilis , Dueggeli Albert , Govaris Christos , Kassis Maria , Dittmar Miriam , Aksoy Dilan , Favre Céline Anne
Published: January 2024

By combining person-centered analysis with latent transition analysis (LTA) and adapting a navigation and negotiation perspective, we examined the effect of the COVID-19 pandemic on adolescents’ depression and anxiety levels as well as their adaptation and success in high school. Focusing on the navigation (individual adaptation) and negotiation (social adaptation) factors that contribute to school success, our data from a longitudinal study in Switzerland (wave 1 in autumn 2020, grade eight [n = 315]; wave 2 in spring 2021, grade eight [n = 257]) revealed four patterns: students with high levels in both dimensions (“thriving”), students with low levels in both dimensions (“demanding”), students with low negotiation but moderate to high navigation (“unsupported bloomers”), and students with high negotiation but low navigation (“encouraged non-achievers”). The “thriving” pattern had about three times more students than the “encouraged non-achiever” pattern did and about five times more students with a lower depression/anxiety profile than the “demanding” pattern did. Parental involvement and reading comprehension were identified as crucial factors in students’ academic achievement, with parental involvement being significantly associated with the “unsupported bloomers” pattern, suggesting that parents can compensate for the lack of teacher academic support and recognition and it can contribute to students’ academic success. Adolescents with high navigation and negotiation resources had higher reading comprehension scores compared to those with lower navigation and negotiation resources. Reading comprehension significantly influenced grades in language subjects and mathematics. The study emphasized the importance of individual and social adaptation factors in promoting academic success and personal growth in high school.
Cutaneous leishmaniasis in a Crohn’s disease patient treated with biological therapy
Authors: Lawgaly Sami A. , Summad Sahar
Published: January 2024

A 55-year-old Libyan woman with Crohn's disease was evaluated for persistent skin ulceration at Benghazi Medical Center, Benghazi-Libya. During the initial visit, she was treated with intravenous antibiotics with no improvement. Pyoderma gangrenosum was considered and she received systemic steroids but she did not improve. Surprisingly, after the skin biopsy, leishmania skin infection was diagnosed and she was started on anti-leishmania therapy after which she showed a great improvement in her skin lesions.
Effectiveness and Efficiency of Mistral Cardioplegia Heat Exchanger for Myocardial Solutions in Cardiac Surgery
Authors: Condello Ignazio , Nasso Giuseppe , Fiore Flavio , Speziale Giuseppe
Published: January 2024

Background

The heat exchangers are composed of two pathways, one for the perfusate (blood or cardioplegia mixture) and one for water. These pathways are separated by material that allows efficient thermal exchange between the fluids. The role of the heat exchanger for the temperature transfer on cardioplegic solution through the delivery system is fundamental for metabolic myocardial preservation and protection in cardiac surgery procedures. The system allows for a user defined, variable concentration of warm, tepid or cold solution to be delivered. In this context we present a retrospective analysis on Mistral Cardioplegia Heat Exchanger and delivery system disposable (Eurosets, Srl, Medolla, Italy) in terms of effectiveness and efficiency during myocardial protection techniques.

Materials and Methods

In this retrospective study we collected 100 cardiac surgery procedures involved the use of Mistral Cardioplegia Heat Exchanger and disposables delivery systems for cardioplegic solutions. Fifty patients used the Mistral Cardioplegia Heat Exchanger, for Blood cardioplegic solution, managed with the temperature of 28 (°C), twenty-five used closed delivery system and twenty-five with soft shell reservoir delivery system; Fifty patients used the Mistral Heat Exchanger, for Crystalloid cardioplegic solution managed with the temperature of 4 (°C), twenty-five were used closed delivery system and twenty-five with soft shell reservoir delivery system. We evaluated the performance in terms of thermal exchange, between the set value and the expected temperature value during the myocardial solution administration in relation to the flow, hematocrit and pressure in the various delivery systems for the blood and crystalloid solution and in terms safety relative at the incidence of adverse event.

Results

The patients with St. Thomas blood cardioplegia solution at 28 °C (set value) Vs the patients with crystalloid Custodiol HTC ® solution at 4 °C (set value) reported a mean value for the cardiopulmonary bypass time of: 93 ± 12 Vs 140 ± 17 (min.); the cross-clamp time was: 65 ± 8 Vs 109 ± 15 (min.); the expected temperature value (°C) during blood cardioplegia for closed blood delivery system Vs soft shell reservoir delivery system was: 28 ± 0.91 Vs 28 ± 0.1, p-value = 0.91; the expected temperature value (°C)during crystalloid Custodiol HTC ® solution for closed delivery system Vs soft shell reservoir delivery system was: 4 ± 0.97 Vs 4 ± 0.13, p-value = 0.97. No adverse event was reported in both groups and subgroups.

Conclusions

The results of this study suggested that the Mistral Cardioplegia Heat Exchanger and delivery systems disposable for cardioplegia (Eurosets, Srl, Medolla, Italy) were effectiveness and efficiency in the management of myocardial protection techniques in terms of temperature and delivery. The systems used were safety and not reported adverse event during the procedures.
Life in a fishbowl: Space and environmental enrichment affect behaviour of Betta splendens
Authors: Oldfield Ronald G , Murphy Emily K
Published: January 2024

The public has expressed growing concern for the well-being of fishes, including popular pet species such as the Siamese fighting fish (Betta splendens). In captivity, male Bettas behave aggressively, often causing injuries and death if housed together. As a result, they are typically isolated in small fishbowls, which has been widely criticised as cruel. To investigate the impact of keeping Bettas in these conditions, we recorded the behaviour of individual males in containers of different sizes that were either bare or enriched with gravel, large rocks, and live plants. When male Bettas were housed individually in small bowls (0.5 L) they spent less time swimming than they did when they were kept in larger aquaria (10, 38, and 208 L). Fish that were kept in enriched containers exhibited more instances of swimming. To determine if two male Bettas housed together might coexist peacefully if given enough space and cover from plants and large rocks, we quantified the behaviour of pairs of male Bettas in bare or enriched aquaria of different sizes (10, 38, 208, 378 L). Fish performed fewer approaches and aggressive displays, but not attacks, and more bouts of foraging, when in larger aquaria. This study shows that the small fishbowls typically used in pet stores suppress swimming behaviour in male Bettas and at least a 10-L aquarium is required to ensure full expression of swimming behaviour. Furthermore, even the use of very large aquaria cannot guarantee peaceful cohabitation between two males.
Selecting for Masculinity: Women’s Under-Representation in the Republican Party
Authors: KARPOWITZ CHRISTOPHER F. , MONSON J. QUIN , PREECE JESSICA R. , ALDRIDGE ALEJANDRA
Published: January 2024

The gap between women’s representation in the Democratic and Republican parties has grown significantly in the last three decades. We argue existing explanations undervalue voters’ contributions to this trend by focusing on voter responses to candidate sex rather than candidate gender. We theorize that Republican voters (especially the most conservative) prefer masculine candidates in intraparty and entry-level elections. Because sex and gender are correlated, this limits the number of Republican women who advance through the political pipeline. Experimental vignettes from two rounds of the Cooperative Congressional Election Study (N = 2,000) and two large surveys of Republicans (N > 10,000) show that Republican (but not Democratic) voters penalize candidates with “feminine” self-presentation regardless of the candidate’s sex. Original data on the self-presentation of Republican candidates for entry-level office (N = 459) confirm Republican candidates often present themselves in gender-stereotypical ways. In short, voters play an underappreciated role in the partisan gap in women’s representation.