Intersection Points Research Articles

Free Fatty Acids and Free Fatty Acid Receptors: Role in Regulating Arterial Function.

The metabolic network's primary sources of free fatty acids (FFAs) are long- and medium-chain fatty acids of triglyceride origin and short-chain fatty acids produced by intestinal microorganisms through dietary fibre fermentation. Recent studies have demonstrated that FFAs not only serve as an energy source for the body's metabolism but also participate in regulating arterial function. Excess FFAs have been shown to lead to endothelial dysfunction, vascular hypertrophy, and vessel wall stiffness, which are important triggers of arterial hypertension and atherosclerosis. Nevertheless, free fatty acid receptors (FFARs) are involved in the regulation of arterial functions, including the proliferation, differentiation, migration, apoptosis, inflammation, and angiogenesis of vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs). They actively regulate hypertension, endothelial dysfunction, and atherosclerosis. The objective of this review is to examine the roles and heterogeneity of FFAs and FFARs in the regulation of arterial function, with a view to identifying the points of intersection between their actions and providing new insights into the prevention and treatment of diseases associated with arterial dysfunction, as well as the development of targeted drugs.

Curve-lifted codes for local recovery using lines

AbstractIn this paper, we introduce curve-lifted codes over fields of arbitrary characteristic, inspired by Hermitian-lifted codes over $$\mathbb {F}_{2^r}$$ F 2 r . These codes are designed for locality and availability, and their particular parameters depend on the choice of curve and its properties. Due to the construction, the numbers of rational points of intersection between curves and lines play a key role. To demonstrate that and generate new families of locally recoverable codes (LRCs) with high availabilty, we focus on norm-trace-lifted codes.

On Some Properties of the Equilateral Triangles with Vertices Located on the Support Sides of a Triangle

The possible positions of an equilateral triangle whose vertices are located on the support sides of a generic triangle are studied. Using complex coordinates, we show that there are infinitely many such configurations, then we prove that the centroids of these equilateral triangles are collinear, defining two lines perpendicular to the Euler’s line of the original triangle. Finally, we obtain the complex coordinates of the intersection points and study some particular cases.

Computing irregular hypar-based quad-mesh patterns for segmented timber shells

Hyperbolic paraboloids, “hypars,” are special types of ruled surfaces. Their geometric properties provide them with loadbearing and stabilizing capacities, as well as distinct esthetic qualities. These attributes become evident in numerous applications in buildings, in many of which concrete or timber is used for the construction of the hypars. Hypars could also be relevant in the context of circular construction and design for disassembly, and the upcycling of construction waste. Due to the geometric simplicity of straight lines, which generate ruled surfaces, hypar-based structures can be designed and built with relatively simple means. They can consist of self-similar or even identical elements, which could facilitate their reuse.Compared to other types of ruled surfaces, such as conoids, hypars have the advantage of being doubly ruled, meaning that structural grids of straight elements can be formed. This paper investigates another interesting property, which is the possibility of creating flat-quad meshes by diagonally connecting the intersection points of the generatrices. This property has been previously described by other scholars, some of which explored its applicability for glass-clad steel grid shells. In this research, we focus on its potential for segmented timber shells that can serve as stand-alone structures, or as modular and reusable building parts, such as façade or roof components. The reusability of such modular units could be achieved by using reversible joints between them.More specifically, our research investigates the design space of construction systems based on such components via computational design and optimization algorithms, such as the memory limited Broyden–Fletcher–Goldfarb–Shanno (LBFGS) algorithm with automatic computation of the gradient, within the Julia programming environment. By applying principles and methods of differential geometry, we study hypars with irregular tilings, enabling the integration of panels with diverse proportions, shapes and sizes, as they can occur in wood production waste. By reducing construction waste, the work aims at reducing the negative environmental impact of the building construction sector. Moreover, irregular tilings could enable a more customized design of acoustic qualities and offer visual variety in segmented hypar based timber structures.The here presented studies show that the proposed optimization method provides a good fit of many tiles to rhombi, particularly when the steepness is not too large. We also show that optimizing towards rectangles provides better results. Overall, the results support the initial assumption that irregular rulings could be a means of adapting to both homogeneous and diverse material stocks.

Ultra-sensitive strain sensor based on Sagnac interferometer with different length panda fiber

A high-sensitivity harmonic Vernier effect (HVE) strain sensor is fabricated by cascading Sagnac interferometer (SI) and Fabry-Perot interferometer (FPI). SI is fabricated by the panda fiber (PF). PF is a typical polarization maintaining fiber (PMF) that has two pressure zones, making it particularly sensitive to strain. SI1, SI2, and SI3 are constructed using PF with lengths of 20 cm, 50 cm, and 80 cm, respectively. They have interference spectra similar to sine waves in the wavelength range of 1250 nm to 1650 nm. Research has found that the sensitivity of SI is directly proportional to the effective PF length under strain action. In addition, if the strain acts on the entire length of the PF, the strain sensitivities of SI1, SI2, and SI3 are 30.4 pm/με, 28.4 pm/με, and 30.1 pm/με, respectively, which are relatively close. Then, FPI is fabricated by splicing single mode fiber (SMF) and quartz capillary, and it is an “SMF-Capillary-SMF” sandwich structure, and the free spectral range (FSR) of FPI is approximately half of that of SI2. FPI and SI2 are cascaded to produce a first-order HVE sensor, further amplifying the strain sensitivity of SI2. The intersection point of the internal envelope based on the HVE sensor spectrum can provide accurate spectral wavelength position and drift, and the strain sensitivity of the HVE sensor reaches 293.0 pm/με, improving the strain sensitivity of SI2 by 10.3 times. The detection limit of the HVE sensor is 0.5 µε as the strain varies from 0 to 700 µε. This HVE strain sensor is relatively easy to manufacture, low-cost, linear and reliable, and can achieve high sensitivity strain measurement. It has certain application value in the field of strain measurement.

Enchanting things: the scientific communication of Julius Sumner Miller

PurposeThe purpose of this paper is to study the popular educational broadcasting of Julius Sumner Miller and its intersections with contemporary science policy and education.Design/methodology/approachThe paper draws on archival research including resources so far unused by historians of science or of broadcasting and audio-visual resources of Sumner Miller’s broadcasts on Australian, Canadian and American television. It begins by contextualising Sumner Miller as both an academic and broadcaster. The second section interprets the core points of his educational philosophy which he articulated in his written and broadcast works. The final section uses his private papers contextualised by works on the history and philosophy of science to interpret and delineate the disparity between Sumner Miller’s influence as a populariser of science and the prevailing trends in scientific policy and teaching.FindingsThis paper proposes that reconstructing the themes and recurring points he asserted in his broadcasts reveals disjunction between Sumner Miller’s high-profile successes and the contemporary trends in both science policy and science education. This paper interprets the circumstance of an internationally known and influential science populariser who was coterminous with but against the grain of the notion of “big science”. He therefore sought to popularise science precisely as it was developing in ways he disparaged.Research limitations/implicationsThis paper breaks new ground by interpreting the different sources, audio-visual and written, created by and about an influential television broadcaster.Originality/valueAlthough he was widely and internationally known, and the range of his influence on science communication is generally noted, Sumner Miller’s broadcasting and the themes and educational philosophy espoused in it is little researched and contextualised. This paper sharpens understanding of his influence but also his points of intersection and disjunction with scientific culture. Hitherto unused archival resources contribute to this understanding.

Linearity Study of Color Measurement Methods in Digital Image Colorimetry

Color metrology is steadily developing in the interests of fundamental and applied science, improving industrial production processes. The author considers the problem of ensuring metrological traceability of color measurements under natural conditions.Digital image colorimetry methods demonstrate good linearity and precision in relatively small application ranges in studies of same type and mainly non-luminous objects. For complex scenes with a wide range of brightnesses, nonlinear functional color rendering models are used that are focused on visual perception, peak brightness of the monitor and reference viewing conditions, which complicates the processing of measurement results and reduces a confidence interval.The described method of measuring the chromaticity coordinates of an object by its digital image is based on tensor calculus and consists of multiple registration of an object and sets of reference samples with different exposure times, building calibration dependencies forming a multidimensional colorimetric scale in color space and determining chromaticity coordinates as points of intersection of color tensors with the plane of the color locus. In order to ensure accuracy and reliability of the measurement results in the software and hardware environments, a validation study of the performance indicators of this method was carried out, one of which is linearity. An experiment based on comparing the developed method with the reference measurement method showed the effectiveness of the developed wide-range measurement method with good linearity (correlation coefficient R=0.97… 0.99, residual relative standard deviation s0≈1–2%) when adjusting from the subjective factor and display device.The experimental materials may be useful to metrologists solving problems of determining the metrological traceability of the color of digital images in media. The article will be of interest to a wide range of readers with professional interests related to the colorimetry of digital images.

Insight into the damage mechanism of KH2PO4 crystals with BaK-SiP by hybrid density functional theory

The laser-induced damage threshold (LIDT) of potassium dihydrogen phosphate (KDP) crystals is one of the key factors affecting the application of KDP crystals for Inertial confinement fusion (ICF). Previous studies have found that Ba, Si impurities can form BaK-SiP defect complexes in KDP crystals. However, the microscopic nature of the defect complexes is still unclear. We precisely calculate defect formation energy (DFE) in various charge states (-1, 0, +1), configuration coordinate diagram (CCD) and optical spectra by hybrid density functional theory. We found BaK-SiP introduce two defect states in the band gap. In the transitions (BaK-SiP)✕+h∙→(BaK-SiP)∙ and (BaK-SiP)✕+e-→(BaK-SiP)′, excited state and ground state have an intersection point in the Marcus inverted region and the activation energies are nearly 0 eV. The results showed that the defect complexes could capture holes and electrons through lattice relaxation, causing significant heat deposition and resulting in crystal damage. This implies a new damage mechanism of KDP crystals is discovered.

Using student projects to enhance learning

The implementation of student projects in undergraduate mathematics and statistics courses is discussed with suggestions and recommendations. Advantages and pitfalls of this teaching tool are presented. A prototypical student project for an elementary mathematics course is described. The features of this sample project serve as models for components of other projects. This illustrative project concerns the locus of intersection points of pairs of tangent lines to a conic section, such that the products of the lines’ slopes are a constant.

Comparison of Changes in the Neutrophil-lymphocyte Ratio (NLR) and Post-surgery Outcomes in Child Patients with COVID-19 and Non-COVID-19

Background Pediatric patients with COVID-19 who undergo surgery have two actual problems, both the presence of a viral inflammatory response and an inflammatory response to surgery, which can affect the outcome of surgery and therapy. NLR is considered a fairly accurate predictor of surgery and COVID-19 infection. Objective This study aims to investigate the effect of changes in neutrophil-lymphocyte (NLR) on post-surgery outcomes in pediatric patients with COVID-19 infection. Methods It is a retrospective cohort study with an observational analysis. This research is a multi-center study on COVID-19 patients using a data bank of pediatric patients with COVID-19 and control patients non COVID-19 children undergoing surgery in three hospitals. Data recorded were age, gender, nutritional status, anesthetic status before surgery, length of stay, repeat surgery, sepsis, septic shock, and mortality. Statistical analysis was performed by the U-mann Whitney test. Results The study sample consisted of 87 total samples consisting of 2 groups, namely the group of pediatric patients with 29 samples with COVID-19 and 58 non-COVID-19 samples. Gender, nutritional status, length of stay, the incidence of reoperation, sepsis, septic shock, and mortality were not significantly different between the two groups with a p<0.05. Risk analysis by looking at the incidence of sepsis and septic shock obtained an intersection point of 2.175 and 2.225, respectively. Analysis of changes in the NLR (delta-NLR) in the mortality events of the COVID-19 group and non-COVID-19 found that the NLR of the COVID-19 group was two times greater than the cut-off NLR of 2,175. Conclusion There is no difference in the outcome of surgery for children with COVID-19 and non-COVID-19 based on the NLR change analysis.

Design and Implementation of a Microstrip Six-Port Reflectometer (SPR) with Enhanced Bandwidth

A compact microstrip six-port reflectometer (SPR) with extended bandwidth is proposed in this paper. The design is based on using 16-dB multi-section coupled line directional couplers and a multi-section 3-dB Wilkinson power divider operating from 1 to 6 GHz. The proposed SPR employs only two calibration standards: a matched load and an open load. As compared to other dielectric substrates, fabricating the proposed SPR involves using a low-cost (FR4) substrate. A novel algorithm is also proposed to estimate the complex reflection coefficient over the frequency ranges at which the standard performance of the circuit components is not fully satisfied. The new algorithm is based on the circles’ intersection points, which have been derived from basic SPR equations, to estimate the complex reflection coefficient. To validate the SPR performance, a multiband microstrip patch antenna has been measured and the resulted reflection coefficient is compared with those obtained using a vector network analyzer (VNA). Results show that the proposed SPR provides a good estimation of the complex reflection coefficient within the frequency range of 1 GHz to 8 GHz. Owing to its compact size and ease of fabrication, the proposed reflectometer is suitable for various microwave broadband applications.

Insights into mechanism of UV-induced degradation in silicon heterojunction solar cells

The ultraviolet-induced degradation (UVID), with losses of up to 11 % after 2000 h-exposure (Sinha et al., 2023) [1], impairs long-term stability of silicon heterojunction (SHJ) solar cells at present. However, the mechanism of UVID has remained only roughly understood till now. Herein, we shed light on the electrical properties of defects in SHJ solar cells to elucidate the underlying mechanism. Defect generation in SHJ solar cells after ultraviolet (UV) irradiation can be observed from photoluminescence (PL) images. Furthermore, we extract the density of states near Fermi level in hydrogenated amorphous silicon (a-Si:H) through analyzing carrier transport mechanism, and find the increment of state density induced by the UV irradiation. In conjunction with Fourier-transform infrared (FTIR) spectra, we ascribe the UV-induced defects to the rupture of Si–H and Si–H2 bonds. Besides, the intersection point between Fermi levels of the c-Si and a-Si:H/c-Si interface can be found shift toward valence band from admittance spectrum analysis, which is the cause of the higher interface state density based on the theory of Fermi energy dependent hydrogen diffusion energy. As a result, a potential mechanism of generation of recombination centers responsible for UVID in SHJ solar cells is proposed, which could provide insights into the possible solutions for UVID and enhance the long-term stability of SHJ solar cells.

A lift-off suppression algorithm to improve the accuracy of ACFM in crack detection of ferromagnetic materials

Ferromagnetic pressurized components are widely used in petroleum, aerospace and nuclear industries, and their safety and stability are the key to the reliable operation of pressure equipment. In the process of crack detection of ferromagnetic materials by ACFM technology, the changes in lift-off distance caused by coating corrosion and irregularity of the surface will greatly affect the extraction of useful detection signals and reduce the detection accuracy. To overcome the drawback, a lift-off suppression algorithm for crack detection of ACFM is proposed. First, a differential strategy is proposed to discover the time-domain lift-off point of intersection (LOI) from the raw detection signals of ACFM for ferromagnetic materials. Then, the corresponding Bx and Bz signals are demodulated based on the amplitude of the LOI. The simulation and experimental results of the surface cracking of ferromagnetic materials by ACFM show that the novel Bx signals obtained according to the proposed method vary in a small range for different lift-off distances. The lift-off invariant property of the LOI enables the method to improve the interference of the lift-off effect on the conventional Bx signals and to enhance the detection accuracy of crack depth of ferromagnetic materials. The novel Bz signals perform consistently with the conventional Bz signals, and are virtually unaffected by the changes in lift-off distance.

A weighted correction of RAPID for precise damage localization in composites using guided waves and principal component analysis

Composite materials are widely used in various engineering applications such as aerospace, automotive, construction, and sports equipment due to their superior mechanical properties, including a high strength-to-weight ratio, design flexibility, and resistance to fatigue and corrosion. However, the complex nature of composite materials and their damage mechanisms poses a challenge to effective Structural Health Monitoring (SHM). Guided waves have been shown to be an effective non-destructive testing technique for localizing damage in Carbon Fiber Reinforced Polymer (CFRP) materials when used with the RAPID (Reconstruction Algorithm for Probabilistic Inspection of Damage) algorithm, which has high robustness and efficiency. However, in some cases, the RAPID algorithm may suffer from inaccuracies in predicting damage positions due to the intersection points among transducer paths. To address this issue, this paper proposes a correction to the original RAPID algorithm. The correction introduces weights to the probability of damage position, computed from the number of intersections that cross that position, to mitigate the impact of the intersection problem. Additionally, the Q-statistic, which is calculated through principal components analysis (PCA), is employed as a damage position indicator. To evaluate the effectiveness of the proposed correction, the measurement data from 12 transducers mounted on a 500 × 500 mm CFRP plate with a reversible damage model placed in different positions are used. The results of the proposed method are compared to the results of RAPID, a suggested geometrical correction of the RAPID algorithm. The findings demonstrate that the proposed correction provides an effective means to predict damage positions with greater accuracy than the original RAPID algorithm. Furthermore, the proposed correction does not compromise the computational simplicity of the RAPID algorithm, which is one of its key advantages.

Illuminating the Bragg intersections as roots of Dirac nodal lines and high-order van Hove singularities

We theoretically reexamine nearly uniform electron models with weak crystalline potentials. In particular, we theorize the modulation of the plane-wave branches at linear regions where multiple Bragg planes intersect. Any such linear intersections involve three or more plane-wave branches diffracted by the periodic potential. Small interbranch interactions can yield various crossing and anticrossing singularities with promised breakdown of the quadratic approximation, extending alongside the intersection lines. Most of the intersections run in low-symmetric paths in the Brillouin zone and therefore we cannot completely characterize their electronic states with standard band-structure plotting methods. The present theory reveals a general mechanism in nearly uniform systems to induce the Dirac nodal lines and van Hove singularities with broken quadratic band approximation in three dimensions, which may host a variety of anomalous low-energy electronic properties. We apply the theory to a recently discovered high-temperature superconductor H3S to interpret the enigmatic density-of-state (DOS) peaking therein. The results show how and the continuous saddle points–the source of the peaked DOS–emerge, as well as reveal the companion Dirac nodal lines hidden in the conduction bands. Published by the American Physical Society 2024

Transformations of ‘traditional everyday life’ in the paradigm of modern transgressive culture

One of the most apparent specific parameters of the modern socio-cultural situation is its obvious transgressive nature. In modern humanitarian science, within the framework of the concept of "transgression" it is customary to mean the objectively existing desire of individuals, human communities and society to overcome certain norms, values and attitudes that have been once established and institutionalized and had time to become traditional. There are whole spheres of human activity whose existence, and especially their development, is simply impossible without a high degree of transgression. First of all, they include science and the arts. Although the study of cultural transgression has a long and fruitful history (including the work of such recognized authorities as Hegel, Bataille, Foucault, etc.), in the new historical realities, the problem also acquires new semantic solutions. First of all, we attribute to such innovations the acutely actualized problem of the "points of intersection" of transgressive culture and human everyday life. Such "intersections" provide many examples of a positive impact on our lives. However, the concomitant negative potential is very high here and over time it turns out to be an increasingly obvious factor of modernity.

Onion-Hash: A Compact and Robust 3D Perceptual Hash for Asset Authentication

The digitalization of manufacturing processes and recent trends, such as the Industrial Metaverse, are continuously increasing in adoption in various critical industries, resulting in a surging demand for 3D CAD models and their exchange. Following this, it becomes necessary to protect the intellectual property of content designers in increasingly decentralized production environments where 3D assets are repeatedly shared online within the ecosystem. CAD models can be protected by traditional security methods such as watermarking, which embeds additional information into the file. Nevertheless, malicious actors may find ways to remove the information from a file. To authenticate and protect 3D models without relying on additional information, we propose a robust 3D perceptual hash generated based on the prevalent geometric features. Furthermore, our geometry-based approach generates compact and tamper-resistant fingerprints for a 3D model by projecting multiple spherical sliced layers of intersection points into cluster distances. The resulting hash links the 3D model to an owner, supporting the detection of counterfeits. The approach was benchmarked for similarity search and evaluated against established state-of-the-art shape retrieval techniques. The results show promising resistance against arbitrary transformations and manipulations, with our approach detecting 25.6% more malicious tampering attacks than the baseline.

At Most Five Limit Cycles in a Class of Discontinuous Piecewise Linear Systems with Three Zones

In this paper, we study the maximum number of limit cycles where planar discontinuous piecewise differential systems can exist formed by three regions separated by a nonregular line. We show that such discontinuous piecewise linear systems can have at most five limit cycles, two of which are of the four intersection points type, the third one is of the two intersection points type and the other two are of three intersection points type. In a setting, we have solved the extended 16th Hilbert problem for these discontinuous piecewise linear differential systems.

The intersection-of-asymptotes method applied to the study of skin temperature changes over time during running exercise

The intersection of asymptotes method is used to describe the changes in skin temperature of the human body during running exercise. Skin temperature variations are induced by thermoregulatory mechanisms, which are influenced by both physiological and environmental factors. The aim of this study is to succinctly and comprehensively connect these factors to create an easily interpretable tool for understanding this process. Based on simplified energy balance equations under dynamic conditions for both the early and late stages of exercise, two asymptotic solutions for skin temperature are derived. The point of intersection between these solutions determines the moment at which the transition from skin vasoconstriction to vasodilation occurs. The shapes and the intersection of the two asymptotes enable the inference and interpretation of actual skin temperature variations throughout the course of exercise.

Anatomical study of the limited osteotomy suture button fixation Latarjet procedure with coracoacromial ligament preservation

To investigate the morphological characteristics of the glenohumeral joint (including the glenoid and coracoid) in the Chinese population and determine the feasibility of designing coracoid osteotomy based on the preoperative glenoid defect arc length by constructing glenoid defect models and simulating suture button fixation Latarjet procedure. Twelve shoulder joint specimens from 6 adult cadavers donated voluntarily were harvested. First, whether the coracoacromial ligament and conjoint tendon connected was anatomically observed and their intersection point was identified. The vertical distance from the intersection point to the coracoid, the maximum allowable osteotomy length starting from the intersection point, and the maximum osteotomy angle were measured. Next, the anteroinferior glenoid defect models of different degrees were randomly constructed. The arc length and area of the glenoid defect were measured. Based on the arc length of the glenoid defect of the model, the size of coracoid oblique osteotomy was designed and the actual length and angle of the coracoid osteotomy were measured. A limited osteotomy suture button fixation Latarjet procedure with the coracoacromial ligament and pectoralis minor preservation was performed and the position of coracoid block was observed. All shoulder joint specimens exhibited crossing fibers between the coracoacromial ligament and the conjoint tendon. The vertical distance from the tip of the coracoid to the coracoid return point was 24.8-32.2 mm (mean, 28.5 mm). The maximum allowable osteotomy length starting from the intersection point was 26.7-36.9 mm (mean, 32.0 mm). The maximum osteotomy angle was 58.8°-71.9° (mean, 63.5°). Based on the anteroinferior glenoid defect model, the arc length of the glenoid defect was 22.6-29.4 mm (mean, 26.0 mm); the ratio of glenoid defect was 20.8%-26.2% (mean, 23.7%). Based on the coracoid block, the length of the coracoid osteotomy was 23.5-31.4 mm (mean, 26.4 mm); the osteotomy angle was 51.3°-69.2° (mean, 57.1°). There was no significant difference between the arc length of the glenoid defect and the length of the coracoid osteotomy ( P>0.05). After simulating the suture button fixation Latarjet procedure, the highest points of the coracoid block (suture loop fixation position) in all models located below the optimal center point, with the bone block concentrated in the anteroinferior glenoid defect position. The size of the coracoid is generally sufficient to meet the needs of repairing larger glenoid defects. The oblique osteotomy with preserving the coracoacromial ligament may potentially replace the traditional Latarjet osteotomy method.