bluuebunny/crossref_metadata_2025_split huggingface dataset:
Jump forecasting in foreign exchange markets: A high‐frequency analysis
Authors: Uzun Sevcan , Sensoy Ahmet , Nguyen Duc Khuong 
Published: January 2023

AbstractUsing tick data for 14 emerging and developed market currencies covering the period from January 2018 until April 2021, we first detect jumps by Lee and Mykland methodology then apply various machine learning algorithms to forecast out of sample jump occurrences and their direction. Our results show that the arrival and the direction of intraday jumps in the foreign exchange market can be predicted with these algorithms combined with liquidity metrics and technical indicators, even for the Covid pandemic period where volatility in the foreign exchange market is very high. Among all the methods considered, multilayer perceptron has the highest average accuracy for jump prediction overall, followed by support vector machine and random forest methodologies with slightly less average accuracy results. Results are robust to alternative sampling schemes. Accordingly, central bankers can adjust liquidity injection timing with these jump prediction models in the foreign exchange markets where they can try to minimize jump strength if not completely eliminate its occurrence. For investors, having information regarding jump occurrence timings gives an opportunity to hedge against foreign exchange risks more efficiently.
Fine characterization of pore evolution of oil shale during thermal simulation
Authors: Liu Gaofei , Liu Rong , Liu Qianghao , Xu Meijing 
Published: January 2023

Oil shale is a kind of organic‐rich fine‐grained sedimentary, whose pore evolution is affected not only by the evolution of inorganic minerals, but also by the thermal evolution of organic matter (OM). Meanwhile, the interaction between inorganic minerals and OM makes the pore evolution of oil shale more complex. Therefore, it is more important to fine the evolution characteristic of pores in different maturity stages and explore the pore size range affected by each influencing factor. This study selects immature oil shale (Tmax = 430°C, TOC = 8.2%) of Nenjiang Formation in Songliao Basin as a research object, and samples with different maturity are obtained through a series of thermal simulation experiments. Combined with petromineralogy, organic geochemistry and reservoir physical property analysis, the evolution process of pores is determined. The volume and specific surface area evolution of mesopores is different from that of macropores in the immature to mature stage, the volume and specific surface area evolution of which is same in the mature to over‐mature stage. There is a strong positive correlation between volumes of macropores and porosity (R2 = 0.94), between volumes of mesopores and specific surface area (R2 = 0.96). The influencing factors mainly affect the pore size less than 400 nm. Hydrocarbon generation of OM affects the whole pore sizes. Residual oil is stored in pores with pore size of 5–25 nm. The effect of carbonate dissolution and pyrite pyrolysis on mesopores is stronger than that of macropores. The transformation of illite/smectite to illite mainly affects the pore size greater than 100 nm. In the whole process of thermal simulation, the OM thermal evolution, the inorganic minerals dissolution and pyrolysis and the clay minerals transformation are the main influencing factors of pore evolution.
Preparation of 3‐Bromo‐1,2,4,5‐tetrazine
Authors: Hoff Lukas V. , Schnell Simon D. , Benchimol Elie , Foutinho Fabio Pereira , Tomio Andrea , Rickhaus Michel , Gademann Karl 
Published: January 2023

AbstractIn this synthetic procedure, a seven‐step protocol for the preparation of monosubstituted 3‐bromo‐1,2,4,5‐tetrazine is presented. The procedure features efficient transformations and purification methods starting from commercially readily available starting materials and affords the title compound on a gram scale with 13 % overall yield in reliable purity (>97 %). Detailed experimental procedures, supported by images and additional notes, allow the preparation of a valuable advanced building block, enabling further applications in bioconjugation, protein labelling, bio‐orthogonal chemistry, heterocycle syntheses, high energy materials, and drug release, among others.
What are the predictors of sexting behavior among adolescents? The positive youth development approach
Authors: Pistoni Carlo , Martinez Damia Sara , Alfieri Sara , Marta Elena , Confalonieri Emanuela , Pozzi Maura 
Published: January 2023

AbstractIntroductionResearch supporting adolescent sexual health and empowerment is needed. The study investigates sexting among adolescents using the resources that characterized the Positive Youth Development Approach (PYD) and considering the impact of parental monitoring. The study aims to describe sexting among three different groups of adolescents (i.e., Non Sexters [NS], Passive Sexters [PS], and Active Sexters [AS]) considering age and sex (first aim). It also seeks to identify predictors among the PYD's resources and parental monitoring that explain the probability of falling into the sexter or the non sexter groups (second aim) as well as the probability of falling into the active or the passive sexter groups (third aim).MethodThe national representative sample was composed of 1866 Italian adolescents: 980 girls and 886 boys aged between 13 and 19 years old (M = 16.26; SD = 1.49). Participants completed a questionnaire that measured sexting behavior, PYD resources, and parental monitoring scales. Chi‐squared and multivariate logistic regressions were performed.ResultsAlmost half of the participants (46.0%) were NS, 36.2% were PS, and 17.8% were AS. Results show that sex, age, Connection, and Child Disclosure are significant predictors of sexting behavior.ConclusionsResults highlighted that sexting can be seen as a relational activity that adolescents use to establish connections as part as their sexual exploration. A parenting approach that promotes disclosure may help adolescents explore safely their sexuality and be accountable. Results also indicate that parents need to build educational alliances with schools to promote sexual health and empowerment among teenagers while preventing risk of harm.
Property and biological effects of the cuttlebone derived calcium phosphate particles, a potential bioactive bone substitute material
Authors: Tangsuksant Thanin , Ummartyotin Sarute , Pongprayoon Thirawudh , Arpornmaeklong Premjit , Apinyauppatham Komsan 
Published: January 2023

AbstractCuttlebone (CB) is a marine waste‐derived biomaterial and a rich source of calcium carbonate for the biosynthesis of the calcium phosphate (CaP) particles. The current study aimed to synthesize CB derived biphasic calcium phosphate (CB‐BCP) and investigate biological activity of the CB‐CaP: hydroxyapatite (CB‐HA), beta‐tricalcium phosphate (CB‐b‐TCP) and biphasic 60:40 (w/w) HA/b‐TCP (CB‐BCP) with the human dental pulp stem cells (hDPSCs). The particles were synthesized using solid state reactions under mild condition and properties of the particles were compared with a commercial BCP as a reference material. Morphology, particle size, physicochemical properties, mineral contents, and the ion released patterns of the particles were examined. Then the particle/cell interaction, cell cytotoxicity and osteogenic property of the particles were investigated in the direct and indirect cell culture models. It was found that an average particles size of the CB‐HA was 304.73 ± 4.19 nm, CB‐b‐TCP, 503.17 ± 23.06 nm and CB‐BCP, 1394.67 ± 168.19 nm. The physicochemical characteristics of the CB‐CaP were consistent with the HA, b‐TCP and BCP. The highest level of calcium (Ca) was found in the mineral contents and the preincubated medium of the CB‐BCP and traces of fluoride, magnesium, strontium, and zinc were identified in the CB‐CaP. The cell cytotoxicity and osteogenic property of the particles were dose dependent. The particles adhered on cell surface and were internalized into the cell cytoplasm. The CB‐BCP and CB‐HA indirectly and directly promote osteoblastic differentiations of the hDPSCs in stronger levels than other groups. The CB‐BCP and CB‐HA were potential bioactive bone substitute materials.
A generic rotamer model to explain the temperature dependence of BSA protein fluorescence
Authors: Chou Yun‐Chu , Lin Tong‐You , Tsai Min‐Yeh 
Published: January 2023

AbstractProtein fluorescence signals essential information about the conformational dynamics of proteins. Different types of intrinsic fluorophores reflect different protein local or global structural changes. Bovine Serum Albumin (BSA) is a transport protein that contains two intrinsic fluorophores: Tryptophan134 (Trp134) and Tryptophan213 (Trp213). This protein displays an interesting temperature dependence of the tryptophan fluorescence. However, the molecular mechanism of the temperature dependence is still unclear. In this work, we propose a generic rotamer model to explain this phenomenon. The model assumes the presence of rotamer‐specific fluorescence lifetimes. The fluorescence temperature dependence is caused by the population shifts between different rotamers due to thermal effects. As a proof of concept, we show that the tryptophan's two fluorescence lifetimes (𝜏1 = 0.4–0.5 ns and 𝜏2 = 2‐4 ns) are sufficient to qualitatively explain the fluorescence intensity change at different temperatures, both in buffer solution (water) and in the protein. To computationally verify our rotamer hypothesis, we use an all‐atom molecular dynamics simulation to study the effects of temperature on the two tryptophans' rotamer dynamics. The simulations show that Trp134 is more sensitive to temperature, consistent with experimental observations. Overall, the results support that the temperature dependence of fluorescence in the protein BSA is due to local conformational changes at the residue level. This work sheds light on the relationship between tryptophan's rotamer dynamics and its ability to fluorescence.
The benefits of participating in a culturally translated youth mentoring program and service‐learning experience for Aotearoa New Zealand mentors
Authors: Deane Kelsey L. , Bullen Pat , Williamson‐Dean Rachel , Wilder Kiri 
Published: January 2023

AbstractThe aim of this article is to demonstrate “mentoring through service‐learning” models can be powerful avenues to support the development of emerging adult practitioners, and are scalable to new global contexts when careful attention is paid to the local culture and evidence‐based principles for mentoring and service‐learning. The study presents outcome findings for mentors who participated in Campus Connections Aotearoa, a culturally translated version of a US‐based service‐learning experience and therapeutic youth mentoring program implemented in New Zealand, based on a mixed‐method, pre‐post evaluation survey involving 62 ethnically diverse mentors (81% female). A large, significant increase in mentoring self‐efficacy and small to moderate significant increases for attunement to others, sociability and leadership, and problem‐solving and perspective‐taking were found. Open‐ended survey responses revealed self‐reported changes in both personal and professional growth. The discussion highlights the importance of theory and evidence‐driven design decisions and an intensive evidence‐informed training curriculum for mentoring‐based service‐learning programs.
The mediating role of resilience in the relationship between helicopter parenting and several indicators of mental health among emerging adults
Authors: Seki Tolga , Haktanir Abdulkadir , Şimşir Gökalp Zeynep 
Published: January 2023

AbstractHelicopter parenting has received much attention in the last decade. The growing literature on this phenomenon illustrates the negative consequences of helicopter parenting. The detrimental effects of helicopter parenting on emerging adults may be especially more present in collectivist cultures. Studies carried out with this population have demonstrated that mental health problems among this group are more prevalent than those of other groups. Hence, an understanding of the factors affecting mental health at this age is critical. The deleterious effects of helicopter parenting on mental health among emerging adults are well‐documented. However, there is a lack of literature investigating the mediating role of resilience between helicopter parenting and mental health issues (i.e., depression, anxiety, and stress). To bridge this gap, we collected data from 402 emerging adults (M = 21.31, SD = 2.01). Our results revealed that although helicopter parenting was a risk factor for several indicators of mental health among emerging adults, resilience mitigates the potential detrimental effect of helicopter parenting.
Confinement effect and efficient adsorption of furfural onto ZIF‐8‐derived microporous carbon
Authors: Yuan Min , Liu Zhiqing , Lv Tiantian , Dong Jinxiang , Shi Qi 
Published: January 2023

AbstractBACKGROUNDThe separation of furfural from a low‐concentration multicomponent and acid‐containing aqueous solution is a highly demanding process; traditional distillation requires an excessive amount of energy. Herein, we demonstrated ZIF‐8‐derived microporous carbon (C) as a promising adsorbent for the separation of furfural using adsorption isotherms, dynamic column adsorption, adsorption kinetics and desorption studies.RESULTSIn the competitive adsorption kinetics experiments with a furfural/acetic acid concentration of 50/20 g L−1, the acetic acid adsorbed in the micropores of NCZIF‐81000C‐800A gradually was replaced by furfural, whereas the amount of acetic acid in the mesopores of NCZIF‐8800C‐800A slowly increased. In addition, the micropores of NCZIF‐81000C‐800A exhibited highly efficient and fast adsorption characteristics toward furfural over a wide furfural/acetic acid concentration range (0–50/0–20 g L−1) with the furfural adsorption capacity reaching an adsorption equilibrium within 10 min. The results show that the high Brunauer–Emmett–Teller surface area of NCZIF‐81000C‐800A is responsible for the high furfural adsorption capacity (1205.3 mg g−1) and the confined microporous structure can strengthen the π–π interactions between porous C and furfural, thereby enhancing the selectivity of furfural/acetic acid (61.4) in the furfural/acetic acid (50/20 g L−1) dynamic column adsorption system. Meanwhile, the desorption ratio of furfural in the dynamic desorption system reached as high as 98.6%.CONCLUSIONThe unique micropore‐confinement effect and excellent adsorption behavior make NCZIF‐81000C‐800A an efficient adsorbent for furfural in the furfural–acetic acid system. © 2023 Society of Chemical Industry (SCI).
Significance and influence of various promoters on Cu‐based catalyst for synthesizing methanol from syngas: a critical review
Authors: Saw Shiva Kumar , Datta Sudipta , Chavan PD , Gupta Pavan K , Kumari Shweta , Sahu Gajanan , Chauhan Vishal 
Published: January 2023

AbstractMethanol synthesis from syngas is an effective method for producing fuel additives, oxygenated fuels, and other chemicals. Several promoted catalytic systems have been tested for the synthesis of methanol. Catalysts based on noble metals are extremely active in generating methanol from syngas. However, sintering, poisoning, and related expenses accounted for the switch to Cu‐based catalysts. The promotion of Cu‐based catalysts, even with small doses of an effective promoter, resulted in a considerable change in product selectivity. A suitable promoter is required for Cu‐based catalysts used in the synthesis of methanol because it significantly impacts the electronic, geometric, or acid/base surface properties, which in turn affect the catalyst's activity and selectivity. It also significantly impacts the interactions between the catalyst's active ingredients. However, the interactions between the active component and the promoter can be adjusted or influenced by appropriate support. The present paper primarily focuses on several promoters in the copper‐based catalyst for synthesizing methanol from syngas. We briefly deliberated on the need for copper‐based catalysts for methanol synthesis, their reaction and mechanism, the reasons for promoter addition concerning their role and influence, the importance of CO2 addition in feed synthesis gas and their impact on the catalyst. This paper mainly highlights the selectivity and activity of various promoted Cu‐based catalysts, although different reaction parameters are the cause of promotion and inhibition in the catalyst. The effects of reaction conditions, including pressure, temperature, gas hourly space velocity (GHSV), and syngas composition, are briefly reported. This paper also comprehensively compares the effects of adding various promoters in small amounts to copper‐based catalysts. This review intends to be illustrative rather than exhaustive. © 2023 Society of Chemical Industry (SCI).
Functional equivalence classes in rats: Repeated olfactory discrimination reversals and delayed stimulus probes
Authors: Galizio Mark , Lawson Kyndra , Shaw Johnathan , Bruce Katherine 
Published: January 2023

AbstractThe simultaneous matching‐to‐sample procedures that are widely used to study stimulus equivalence in human participants have generally been unsuccessful in animals. However, functional equivalence classes have been demonstrated in pigeons and sea lions using a concurrent repeated reversal discrimination procedure. In this procedure, responding to one set of stimuli is reinforced but responding to a different set is not and the set associated with reinforcement is changed with multiple reversals during the experiment. The experiments reported here were designed to assess whether functional equivalence classes could be demonstrated in rats using similar techniques. Rats were initially trained with two sets of olfactory stimuli (six odors/set). Following many reversals, probe reversal sessions were conducted in which rats were exposed to a subset of the members of each set and, later in the session, the withheld stimuli were introduced. Responding to these delayed probe trials in accord with the reversed contingencies constituted transfer of function. There was some evidence of transfer in Experiment 1, but the effects were relatively weak and variable. Experiment 2 introduced procedural changes and found strong evidence of transfer of function consistent with the formation of functional equivalence classes. These procedures offer a promising strategy to study symbolic behavior in rodents.
Choice dynamics in concurrent ratio schedules of reinforcement
Authors: Bellow Daniel , Lattal Kennon A. 
Published: January 2023

AbstractThe generalized matching law predicts performance on concurrent schedules when variable‐interval schedules are programmed but is trivially applicable when independent ratio schedules are used. Responding usually is exclusive to the schedule with the lowest response requirement. Determining a method to program concurrent ratio schedules such that matching analyses can be usefully employed would extend the generality of matching research and lead to new avenues of research. In the present experiments, ratio schedules were programmed dependently such that responses to either of the two options progressed the requirement on both schedules. Responding is not exclusive because the probability of reinforcement increases on both schedules as responses are allocated to either schedule. In Experiment 1, performance on concurrent variable‐ratio schedules was assessed, and reinforcer ratios were varied across conditions to investigate changes in sensitivity. Additionally, the length of a changeover delay was manipulated. In Experiment 2, performance was compared under concurrently available, dependently programmed variable‐ratio and fixed‐ratio schedules. Performance was well described by the generalized matching law. Increases in the changeover delay decreased sensitivity, whereas sensitivity was higher when variable‐ratio schedules were employed, compared with fixed‐ratio schedules. Concurrent ratio schedules can be a viable approach to studying functional differences between ratio and interval schedules.
Ocular microvasculature in adult Xenopus laevis: Scanning electron microscopy of vascular casts
Authors: Lametschwandtner Alois , Minnich Bernd 
Published: January 2023

AbstractThe microvascular anatomy of choriocapillaris, iris, ciliary body, and superficial vascular hyaloid system of eyes was studied in the permanent aquatic Xenopus laevis by scanning electron microscopy of vascular casts and was compared with that published in two semiaquatic ranid species (Rana esculenta and Rana temporaria), and the urodelian species Triturus criststus carnifex. Results showed that the choriocapillaris in Xenopus consisted of a dense meshwork of wide capillaries displaying polygonal arrays at the scleral side with venules leaving the centers and arterioles supplied from the periphery. The choriocapillaris lacked the multilayered capillary meshwork described in ranids. Iris and ciliary body were supplied by nasal and temporal branches of the iridial artery, which either originated with a common stem from the hyaloid artery or arose as individual vessels from the proximal portions of the semicircular nasal and temporal branches of the hyaloid artery. These branches ran in the pupillary margin and supplied the two‐dimensional capillary network of the iris, as well as the three‐dimensional network of the ciliary body. Iris and ciliary body drained via parallel running vasa recta into the choriocapillaris. The superficial vascular hyaloid bed (system) was supplied by the hyaloid artery. This artery coursed along the scleral surface of the ventrotemporal choriocapillaris toward the ora serrata, where it bifurcated into a temporal and a nasal semicircular branch. Seven to 10 arterial meridional twigs arose from these branches and supplied the superficial hyaloid capillary bed. Capillaries drained into branches of the hyaloid vein, which ascended toward the ora serrata, where the hyaloid vein joined the temporal branch of the ciliary vein.
Observation of Topologically Enabled Complete Polarization Conversion
Authors: Chen Fujia , Gao Zhen , Zhang Li , Chen Qiaolu , Yan Qinghui , Xi Rui , Jin Liqiao , Li Erping , Yin Wenyan , Chen Hongsheng , Yang Yihao 
Published: January 2023

AbstractExploiting topological ideas has been a major theme in modern photonics, which provides unprecedented opportunities to design photonic devices with robustness against defects. While most previous works in topological photonics have focused on band theory, recent theories extend the topological concepts to the analysis of scattering matrices and suggest a topological route to complete polarization conversion (CPC). Here, the experimental observation of the topological CPC is reported. Using angle‐resolved reflection measurements, it is unveiled experimentally that the CPC between arbitrary two polarizations occurs at vortex singularities of reflection coefficients in momentum space, reflecting its topological nature. Besides, it is visualized directly that for a given input polarization, the output one can cover the entire Poincaré sphere over a wide frequency range by varying the incident angle, guaranteed by the topological nature of CPC, which is in sharp contrast to the conventional polarization–conversion approaches that usually suffer from the bulky volume, limited choice of eigen‐polarization states, or narrow operation bandwidths. Remarkably, that BICs lie on the critical coupling curves that define the condition for CPC is experimentally demonstrated. This work paves the way to exploring the topological properties in scattering matrices for controlling light polarization and creating robust photonics devices.