Maximum Size Research Articles

Adaptive promising zone design for cancer immunotherapy with heterogeneous delayed treatment effect

ABSTRACT Indirect mechanisms of cancer immunotherapies result in delayed treatment effects that vary among patients. Consequently, the use of the log-rank test in trial design and analysis can lead to significant power loss and pose additional challenges for interim decisions in adaptive designs. In this paper, we describe patients’ survival using a piecewise proportional hazard model with random lag time and propose an adaptive promising zone design for cancer immunotherapy with heterogeneous delayed effects. We provide solutions for calculating conditional power and adjusting the critical value for the log-rank test with interim data. We divide the sample space into three zones – unfavourable, promising, and favourable –based on re-estimations of the survival parameters, the log-rank test statistic at the interim analysis, and the initial and maximum sample sizes. If the interim results fall into the promising zone, the sample size is increased; otherwise, it remains unchanged. We show through simulations that our proposed approach has greater overall power than the fixed sample design and similar power to the matched group sequential trial. Furthermore, we confirm that critical value adjustment effectively controls the type I error rate inflation. Finally, we provide recommendations on the implementation of our proposed method in cancer immunotherapy trials.

Allometric Scaling Reveals Evolutionary Constraint on Odonata Wing Cellularity via Critical Crack Length.

Scaling in insect wings is a complex phenomenon that seems pivotal in maintaining wing functionality. In this study, the relationship between wing size and the size, location, and shape of wing cells in dragonflies and damselflies (Odonata) is investigated, aiming to address the question of how these factors are interconnected. To this end, WingGram, the recently developed computer-vision-based software, is used to extract the geometric features of wing cells of 389 dragonflies and damselfly wings from 197 species and 16 families. It has been found that the cell length of the wings does not depend on the wing size. Despite the wide variation in wing length (8.42 to 56.5 mm) and cell length (0.1 to 8.5 mm), over 80% of the cells hada length ranging from 0.5 to 1.5 mm, which waspreviously identified as the critical crack length of the membrane of locust wings. An isometric scaling of cells is also observed with maximum size in each wing, which increased as the size increased. Smaller cells tended to be more circular than larger cells. The results have implications for bio-mimetics, inspiring new materials and designs for artificial wings with potential applications in aerospace engineering androbotics.

Study of the Fenton Oxidative Reaction on a Culture of Human Fibroblast Cells Incubated with Ablated CeO<sub>2</sub> Particles

Purpose. Study of the bioprotective properties of ablated cerium dioxide nanoparticles in relation to immortalized human fibroblasts under conditions of oxidative stress caused by the Fenton reaction.Methods. Cerium dioxide nanoparticles with pronounced antioxidant properties were obtained using laser ablation. The average maximum sizes of ablated particles of oxidized cerium in non-centrifuged and centrifuged at a speed of 1000 rpm nanodispersed aqueous solutions were revealed using the method of atomic force microscopy. The spectrophotometric method revealed that ablated cerium dioxide nanoparticles exhibit antioxidant properties and prevent the degradation of the methylene blue dye during the Fenton reaction. Cell culture samples were mapped using scanning electron microscopy using an energy-dispersive attachment after their incubation with ablated cerium dioxide nanoparticles. Using MTT analysis, the effect of ablated cerium dioxide nanoparticles on the survival of BJ TERT cell culture in the Fenton reaction was studied. Non-centrifuged and centrifuged at a speed of 1000 rpm nanodispersed solutions of oxidized cerium were used. The antioxidant activity of cerium dioxide nanoparticles after 6- and 24-hour incubation was studied.Results. The average limiting sizes of ablated cerium dioxide nanoparticles have been established, the values of which are (61,95±0,1) nm for a non-centrifuged aqueous solution and (56,59±0,1) nm for an aqueous solution centrifuged at a microcentrifuge speed of 1000 rpm. It was revealed that in the presence of ablated cerium dioxide nanoparticles, the degree of oxidative degradation of methylene blue during the Fenton reaction was significantly reduced. It was found that with an increase in the concentration of ablated cerium dioxide nanoparticles from 20 to 1000 mg/l, their antioxidant effect increased. From the obtained SEM images of cell cultures with ablated cerium dioxide nanoparticles, it follows that the nanoparticles are captured by cells during incubation and can have a significant effect on oxidative processes during the Fenton reaction. Statistical analysis based on the results of the MTT assay showed that 6-hour and 24-hour incubation with ablated cerium dioxide nanoparticles had a pronounced protective effect on the BJ TERT cell line.Conclusion. This work shows that during the Fenton reaction, cerium dioxide nanoparticles prevent the oxidative degradation of the methylene blue dye. When immortalized human fibroblasts are incubated, ablated cerium oxide nanoparticles are taken up by the cells and have a significant protective effect on them in the oxidative reaction. The high antioxidant activity of nanoparticles is determined by the high content of functional defects on the surface of nanoparticles obtained under sharply nonequilibrium conditions of laser ablation.

Classification of schizophrenic traits in transcriptions of audio spectra from patient literature: artificial intelligence models enhanced by geometric properties

Schizophrenia is a severe mental illness that affects approximately 1% of the global population and presents significant challenges for patients, families, and healthcare professionals. Characterized by symptoms such as delusions, hallucinations, disorganized speech or behavior, and cognitive impairment, this condition has an early onset and chronic trajectory, making it a debilitating challenge. Schizophrenia also imposes a substantial burden on society, exacerbated by the stigma associated with mental disorders. Technological advancements, such as computerized semantic, linguistic, and acoustic analyses, are revolutionizing the understanding and assessment of communication alterations, a significant aspect in various severe mental illnesses. Early and accurate diagnosis is crucial for improving prognosis and implementing appropriate treatments. In this context, the advancement of Artificial Intelligence (AI) has provided new perspectives for the treatment of schizophrenia, with machine learning techniques and natural language processing allowing a more detailed analysis of clinical, neurological, and behavioral data sets. The present article aims to present a proposal for computational models for the identification of schizophrenic traits in texts.  The database used in this article was created with 139 excerpts of patients' speeches reported in the book “Memories of My Nervous Disease” by German judge Daniel Paul Schreber, classifying them into three categories: 1 - schizophrenic, 2 - with schizophrenic traits and 3 - without any relation to the disorder. Of these speeches, 104 were used for training the models and the others 35 for validation.Three classification models were implemented using features based on geometric properties of graphs (number of vertices, number of cycles, girth, vertex of maximum degree, maximum clique size) and text entropy. Promising results were observed in the classification, with the Decision Tree-based model [1] achieving 100% accuracy, the KNN- k-Nearest Neighbor model observed with 62.8% accuracy, and the 'centrality-based' model with 59% precision. The high precision rates, observed when geometric properties are incorporated into Artificial Intelligence Models, suggest that the models can be improved to the point of capturing the language deviation traits that are indicative of schizophrenic disorders. In summary, this study paves the way for significant advances in the use of geometric properties in the field of psychiatry, offering a new data-based approach to the understanding and therapy of schizophrenia.

Molecular Transportation Conversion of Membrane Tension Using a Mechanosensitive Channel in Asymmetric Lipid-Protein Vesicles.

Giant lipid vesicles composed of a lipid bilayer form complex membrane structures and enzyme network reactions that can be used to construct well-defined artificial cell models based on microfluidic technologies and synthetic biology. As a different approach to cell-mimicking systems, we formed an asymmetric lipid-amphiphilic protein (oleosin) vesicle containing a lipid and an oleosin monolayer in the outer and inner leaflets, respectively. These asymmetric vesicles enabled the reconstitution and function of β-barrel types of membrane proteins (OmpG) and the fission of vesicles stimulated by lysophospholipids. These applications combine the advantages of the high stability of lipids and oleosin leaflets in asymmetric lipid-oleosin vesicles. In this study, to evaluate the versatility of this asymmetric lipid-oleosin vesicle, the molecular transport of the mechanosensitive channel of large conductance (MscL) with an α-helix was evaluated by changing the tension of the asymmetric vesicle membrane with lysophospholipid. A nanopore of MscL assembled as a pentamer of MscLs transports small molecules of less than 10 kDa by sensing physical stress at the lipid bilayer. The amount and maximum size of the small molecules transported via MscL in the asymmetric lipid-oleosin vesicles were compared to those in the lipid vesicles. We revealed the existence of the C- and N-terminal regions (cytoplasmic side) of MscL on the inner leaflet of the asymmetric lipid-oleosin vesicles using an insertion direction assay. Furthermore, the change in the tension of the lipid-oleosin membrane activated the proteins in these vesicles, inducing their transportation through MscL nanopores. Therefore, asymmetric lipid-oleosin vesicles containing MscL can be used as substrates to study the external environment response of complex artificial cell models.

The qudit Pauli group: non-commuting pairs, non-commuting sets, and structure theorems

Qudits with local dimension d>2 can have unique structure and uses that qubits (d=2) cannot. Qudit Pauli operators provide a very useful basis of the space of qudit states and operators. We study the structure of the qudit Pauli group for any, including composite, d in several ways. To cover composite values of d, we work with modules over commutative rings, which generalize the notion of vector spaces over fields. For any specified set of commutation relations, we construct a set of qudit Paulis satisfying those relations. We also study the maximum size of sets of Paulis that mutually non-commute and sets that non-commute in pairs. Finally, we give methods to find near minimal generating sets of Pauli subgroups, calculate the sizes of Pauli subgroups, and find bases of logical operators for qudit stabilizer codes. Useful tools in this study are normal forms from linear algebra over commutative rings, including the Smith normal form, alternating Smith normal form, and Howell normal form of matrices. Possible applications of this work include the construction and analysis of qudit stabilizer codes, entanglement assisted codes, parafermion codes, and fermionic Hamiltonian simulation.

Intersecting families of transformations

Consider [Formula: see text] and [Formula: see text] to represent the full transformation semigroup and the symmetric group on the set [Formula: see text], respectively. A subset [Formula: see text] of [Formula: see text] is called an intersecting family if any two transformations [Formula: see text] coincide at some point [Formula: see text]. An intersecting family [Formula: see text] is called maximum if no other intersecting family [Formula: see text] exists with [Formula: see text]. Frankl and Deza [On the maximum number of permutations with given maximal or minimal distance, J. Combin. Theory Ser. A 22(3) (1977) 352–360] established that the cardinality of a maximum intersecting family of [Formula: see text] equals [Formula: see text]. Subsequent research demonstrated that a maximum intersecting family of [Formula: see text] forms a coset of a stabilizer of one point, as shown by Cameron and Ku [Intersecting families of permutations, European J. Combin. 24(7) (2003) 881–890] and independently by Larose and Malvenuto [Stable sets of maximal size in Kneser-type graphs, European J. Combin. 25(5) (2004) 657–673]. Define [Formula: see text], where [Formula: see text] denotes the image set of [Formula: see text]. This paper presents a formula for the cardinality of a maximum intersecting family of [Formula: see text]. It then characterizes the maximum intersecting families of [Formula: see text] and concludes by determining the number of maximum intersecting families of [Formula: see text].

STUDYING THE STRENGTH OF DISSIMILAR JOINTS OF AISI 430 AND 301 STAINLESS STEEL WELDED AT DIFFERENT WELDING PARAMETERS

Investigating the best welding parameters for resistance spot welding joints between AISI 430 and AISI 301 stainless steels was the primary focus of this study. This research involved welding samples of these stainless steel types using various welding parameters. Ferritic stainless steel (AISI 430) and austenitic stainless steel (AISI 301) were subjected to resistance spot welding, and different welding conditions were applied to produce a range of samples. The study specifically analyzed the influence of the welding current (2.5, 3.1 and 3.7) kA and welding time (40, 70 and 100) ms on the joining capability of these stainless steels. To determine the best welding parameters, microhardness measurements and tensile-shear tests were performed on the welded materials. The results indicated that increasing the welding current and welding time led to an increase in the tensile load. The maximum tensile-shear load 2036 N was observed at 3.7 kA and 100 ms. However, after a salt spray test (48 and 96) h, a serious decrease in the tensile load from 2036 N to 750 was observed at the high current 3.7 kA and time (70 and 100) ms. At 3.1 kA and 70 ms before and after the salt test, its value remained relatively constant, and the corrosion resistance of the weld joint was at the best level. The microhardness of the heat-affected zone increased, reaching its maximum point (for 3.1 kA and 70 ms: 347.3 HV and for 3.1 kA 100 ms: 369 HV) in the fusion zone. Moreover, the increase in the welding time and current was associated with an increase in the nugget size. The maximum nugget size was 3.61 mm at 3.7 kA and 100 ms.

A proposed mathematical model to help preoperative planning between RIRS and MiniPerc for renal stones between 10 and 20mm using holmium:Yag laser (Cyber Ho): the stone management according to size-hardness (SMASH) score.

To evaluate the performance of a mathematical model to drive preoperative planning between RIRS and MiniPerc (MP) for the treatment of renal stones between 10 and 20mm. Patients with a renal stone between 10 and 20mm were enrolled. A mathematical model named Stone Management According to Size-Hardness (SMASH) score was calculated: hounsfield units (HU) χ stone maximum size (cm)/100. Patients were divided into 4 groups: RIRS with score < 15 (Group A), RIRS with score ≥ 15 (Group B), MP with score < 15 (Group C), MP with score ≥ 15 (Group D). Cyber Ho device was always used. Stone free rate (SFR) was assessed after 3 months. Complication rate and need for auxiliary procedures were evaluated. Between January 2019 and December 2021, 350 patients were enrolled (87, 88, 82 and 93 in Groups A, B, C and D). Mean stone size was 13.1 vs 13.3mm in Group A vs B (p = 0.18) and 16.2 vs 18.1mm in Group C vs D (p = 0.12). SFR was 82%, 61%, 75% and 85% for Groups A, B, C and D. SFR was comparable between Groups C and D (p = 0.32) and Groups A and C (p = 0.22). SFR was significantly higher in Group A over B (p = 0.03) and in Group D over B (p = 0.02). Complication rate was 2.2%, 3.4%, 12.1%, 12.9% for Groups A, B, C, D. RIRS and MP are both safe and effective. The mathematical model with the proposed cut-off allowed a proper allocation of patients between endoscopic and percutaneous approaches.Registration number of the study ISRCTN55546280.

Impact of ultracentrifugal milling on the thermo-rheological, functional, and physicochemical properties of yellow and green pea flour

Pea seeds conversion into flour enhance their incorporation into diverse food systems. However, milling impacts changes in the flour's physicochemical and technofunctional properties. In this study, the impact of ultracentrifugal milling on the thermal, rheological, functional and physicochemical properties of flour from yellow and green pea varieties was investigated. Pea seeds were milled to maximum particle sizes of 0.25, 0.50 and 1.00 mm based on different screen aperture fitted to the ultracentrifugal mill. Scanning electron microscopy showed that flour samples milled with the 0.25 mm screen aperture had higher disentangled protein particles but more damaged starch particles compared to the 0.50 and 1.00 mm screens. The FTIR analysis indicated similar spectra with varying functional groups at corresponding wavelengths but different absorbance intensity. At 2853 cm−1 wavelength, additional peak for cellulose was detected in 0.25 mm milling condition but absent in other samples. Flour milled to 0.25 and 0.50 mm maximum particle size had the most desirable outcomes to rheological and thermal attributes. Principal component analysis score plots elucidated relationship between milling conditions, flour functionality and pea variety with PC1 at 46.64% and PC2 at 34.53%. These findings demonstrate that milling conditions can be a potential tool to manipulate pea flour functionality.

Influence of deposition temperature on the defect mediated persistence photo-conducting behaviour of spray coated Zn0.96Nd0.04O thin films

The incorporation of Neodymium into ZnO lattice enhances the photo conducting property of the deposited films which are strongly dependent on preparation conditions. Hence, the comprehensive work carried out to understand the influence of deposition temperature (300 oC – 500 oC) on the persistence photoconductivity of Zn0.96Nd0.04O films deposited on glass substrates using spray pyrolysis method. The maximum crystallite size of ∼16.3 nm with minimum dislocation density and strain values were noticed for the films deposited at 450 oC. The mixed fibrous -granular morphology was noticed in the deposited films. The maximum transparency above 90 % in the visible region and an increased bandgap of 3.42 eV was observed in the films deposited at 450 oC. The percentage of defects were calculated using the area under the curve of photoluminescence spectra. The charge carrier density of 1.7×1017 cm-3, mobility of 62.8 cm2/Vs and lesser resistivity of 1.3×102 Ω cm were noted for the films deposited at 450 °C. Under the illumination of UV light, the photocurrent of Zn0.96Nd0.04O films deposited at 450 °C increased by four orders. The persistence in the photo resistance was due to the presence of Zn and O related defects, which acts as trap centres. The variation of photo resistance with time indicates the films deposited at 450 °C has faster photo response due to the faster electron – hole recombination process. The maximum photocurrent at 360 nm was noted for the films synthesised at 450 °C due to improved crystallinity with stoichiometry nature of the films. Hence, the Zn0.96Nd0.04O films deposited at 450 °C suitable for light dependent resistor and fixed wavelength UV photodetector applications.

Presence of microplastics in the groundwater of volcanic islands, El Hierro and La Palma (Canary Islands)

The increasing amount of plastic litter worldwide is a serious problem for the environment and its biodiversity, ecosystems, animal and human welfare and the economy. The degradation of these plastics leads to microplastics (MPs), which have been reported for the first time in groundwater in the Canary archipelago. This research investigates the presence of MPs at nine different points on La Palma and El Hierro, where samples were collected in galleries, wells and springs during the month of December 2022. Six different polymers were found with Fourier transform infrared spectroscopy (FTIR) – polypropylene (PP), polyethylene (PE), cellulose (CEL), polyethylene terephthalate (PET), polystyrene (PS) and polymethyl methacrylate (PMMA). The particle concentrations found ranged from 1 to 23 n/L, with a maximum particle size of 1900 μm, the smallest being 35 μm. PP and PE were the most common polymers found in the analysis, associated with the use of packaging, disposable products, textiles and water pipes, related to poorly maintained sewerage networks where leaks occur, allowing these MPs to escape into the environment and end up in groundwater. The detection of microplastic pollution in groundwater emphasises environmental hazards, including biodiversity disruption and water source contamination. Additionally, it presents potential risks to human health by transferring contaminants into the food chain and through respiratory exposure.

Porosity and phase composition effects on SHS-NiTi structure and mechanical properties

NiTi samples with 59–70% porosity were obtained by the self-propagating high-temperature synthesis (SHS) using Ti, Ni, and NiTi powders as inert. The maximum and average pore sizes increase, while the maximum and average dimensions of the bridges decrease with porosity, controlled by adjusting the amount of inert additives, based on the surface and cross-sectional microscopy studies. The phase composition of porous NiTi was determined by X-ray diffraction. The alloy contains an austenitic B2 TiNi phase, a martensitic B19′ TiNi phase, and a secondary Ti2Ni phase. SHS-NiTi samples with different porosity were tested by uniaxial compression, revealing mechanical properties’ dependence on porosity. It is shown that with an 11% increase in the NiTi alloy porosity, the yield and compressive strength are reduced by almost a factor of 2.

Tensile performance and cracking characteristics of sustainable textile-reinforced cementitious composites utilizing expanded glass aggregate and fly ash replacement

In this study, sustainable textile-reinforced cementitious composites (TRC) were developed using lightweight expanded glass (EG) aggregates combined with fly ash (FA) as a partial cement replacement. Recycled nylon fibers were incorporated to enhance the cementitious matrix. The tensile performances and cracking characteristics of the developed TRC materials were comprehensively investigated. The key parameters investigated included the lightweight aggregate size, FA replacement content, fabric reinforcement ratio, and volume fraction of additional nylon fibers. The experimental results revealed that utilizing FA replacement content within the range of 20–30% and employing maximum EG aggregate sizes of 0.5 mm and 1.0 mm had a negligible influence on cracking characteristics and the tensile performance of TRC. Conversely, an adverse effect was observed with a 50% FA replacement content and a maximum EG size of 2.0 mm. Moreover, employing a higher fabric reinforcement ratio and an increased volume fraction of dispersed nylon fibers in the matrix endowed the TRC with favorable tensile performance and cracking characteristics. Eventually, an analytical model simulating the tensile stress-strain responses of TRC composites based on the cracking characteristics and stochastic matrix theory was proposed. The proposed model exhibits a reasonable correlation with the experimental results.

Particle size distribution (PSD) estimation using unmanned aerial vehicle (UAV) photogrammetry for rockfill shear strength characterization

AbstractThe strength of rockfills and waste materials is significantly influenced by their particle size distribution (PSD). For large waste rockfills, PSD is fundamental to determine the shear behavior. Traditionally, PSD for rockfill, used in materials like coarse-grained aggregates, has been obtained through physical sieving. However, the particle sizes in hard rockfills can vary significantly from small particles (&lt; 20 cm diameter) to large blocks or boulders over 100 cm, with the maximum size limited by the in situ ground conditions and blasting performance. Essentially, the sieving process is impractical, considering the scale of the mine waste dumps and the time required. Therefore, in this study, a workflow using digital detection to estimate the PSD is presented, aiming to quantify the waste dump shear strength using Barton–Kjaernsli empirical criterion. PSD from UAV is validated using manual field measurements of individual boulders. The error for coarse characteristic size prediction ranges within ± 4 mm, and the increase in the data collection frequency, area covered, and resolution of fragmentation measurement for rockfills and waste dumps using UAV allows to improve the statistical reliability of the PSD and fragmentation measurement.

Dynamic recrystallization behaviors and cracking mechanism for the hot deformation of new-generation high nitrogen bearing steel

In this work, the hot deformation behaviors of the high-nitrogen steel X30CrMoN15-1 from 900 °C to 1200 °C have been investigated. The microstructure observation indicates that the maximum DRXed grain size reaches 59.05 μm under the deformation temperature of 1200 °C with strain rate of 0.005 s−1, while the minimum grain size is 2.12 μm under the condition of 900 °C with strain rate of 1 s−1. The fully dynamic recrystallization (DRX) occurs at the conditions of high temperature and high strain rate (1000 °C − 1200 °C, 1 s−1 –5 s−1). There are two main mechanisms of crack formation. Under lower temperatures (900 °C-1000 °C), the significant stress concentration produced by M2(C, N) should be responsible for crack propagation along the DRXed grain boundaries. As the temperature increases to 1100 °C, the formation of cracks is mainly attributed to the uncoordinated deformation and huge pinning of dislocations by Lomer-Cottrell (L-C) locks. A new hot processing map has been established to reveals that the optimal processing domains are located at 1020 °C − 1090 °C with strain rate of 0.37 s−1 –4 s−1 and 1140 °C − 1200 °C with strain rate of 2 s−1 –5 s−1.

Relationship between pathohistological characteristics of the tumor and distant metastasis of differentiated thyroid cancer

Papillary thyroid cancer has the most favorable prognosis for patients. According to the recommendations of the National Comprehensive Cancer Network (NCCN), organ‑sparing surgery can be performed for such patients without radioactive iodine therapy (RIT). However, some factors, for example, vascular invasion, multifocality, the presence of regional metastases, etc. increase stratification risks for the patient and give the reason to perform more voluminous surgical interventions and conduct RIT. With differentiated thyroid cancer (DTC), the 5‑year and 10‑year overall survival rates reach 100% and 96%, respectively.&#x0D; Objective — to investigate the relationship between the pathohistological characteristics of the DTC tumor and distant metastasis.&#x0D; Materials and methods. The study involved 522 patients aged 4 to 79 years (the mean age 40.2±0.6 years) after previous thyroid cancer surgery and RIT. Patients were divided into two groups depending on the presence of distant metastases: 28 (5.4%) with distant metastases and 494 (94.6%) patients without distant metastases.&#x0D; Results. Using the data of pathohistological findings, both groups were compared according to the following criteria: pathomorphological DTC subtype, vascular invasion, other extraordinary invasion, multifocality, the size of the primary tumor, the size of the largest focus and the total size of foci for multifocal cancers, the number and maximum size of metastases in the central and lateral lymphatic collectors of the neck.&#x0D; Conclusions. No significant relationship has been found between the pathomorphological subtype of differentiated thyroid cancer, the presence of vascular and extra‑organ invasion, and the presence of distant metastases, but a relationship was found with multifocality. In the group of patients with distant metastases, a larger size of the primary focus, and a larger size and number of regional metastases were determined.&#x0D;  

Morphological peculiarity of the fossil bison (&lt;i&gt;Bison priscus&lt;/i&gt;) from Yakutia

The steppe bison (Bison priscus) is one of the most widespread and numerous representatives of the mammoth fauna. However, the features of the extinction of steppe bison at the end of the Pleistocene and their replacement by modern forms of the American bison (Bison bison) and European bison (Bison bonasus) have not yet been fully studied. Thus, complete skulls of fossil steppe bison are of great interest for studies on taxonomy and kinship relations in the genus Bison. This article presents the results of a study of the finely preserved skull of a fossil bison found in the Verkhoyansk district (Yakutia). This skull was compared by its morphological and osteometric features with other bison skulls, which were found at different times and locations in Upper Pleistocene deposits, as well as with the skulls of modern American bison Bison bison from the collection of the Zoological Museum of the Lomonosov Moscow State University. Standard morphometric indicators of bison skulls and horns were obtained using the Skinner and Kaisen measurement methods. Analysis showed that skulls of Bison priscus from Late Pleistocene sediments of Yakutia, according to most parameters, correspond to the maximum size of modern American bison Bison bison or even larger than the latter. The horns of bison from the Late Pleistocene are 1.5–2 times larger in size than the horns of modern bison and are comparable to those of the Middle Pleistocene long-horned bison B. p. crassicornis Richardson (=longicornis). The disproportion in the size of the skull and horns of the Late Pleistocene bison is due to their habitat in the open landscapes of the Arctic steppe. The morphological uniqueness of the steppe bison of the Late Pleistocene in Yakutia has prospects for further research, because it deserves to be identified as an independent taxon (subspecies), which is relevant for regional paleontology and stratigraphy.

Molecular dynamics study on relaxation of supercooled liquid water at different cooling rates

The relaxation in supercooled liquids is a phenomena by which the thermodynamic system starts transforming from one state to other after losing its high end thermodynamic properties (i.e. density, potential energy, enthalpy, etc.) with a significant change. Since the relaxation phenomena is quite challenging to observe, specifically near the transition region of liquid water. Hence, the thermodynamic analysis for understanding the relaxation phenomena of liquid water in supercooled region from the high density liquid (HDL) state to low density amorphous (LDA) state are important from both fundamental and as well as applied perspectives. Therefore, we focused our study on performing thermodynamic analysis on the relaxation of super-cooled liquid water by using a monatomic water (mW) potential model with an isothermal-isobaric (NPT) molecular dynamics (MD) simulation technique at zero pressure under different cooling rates. In this work, we examine the relaxation in terms of root mean square (RMS) fluctuation of two and three-body potential energy of the maximum size of four coordinated cluster under different cooling rates. The predicted data over this study shows the independency of the cooling rate, where the relaxation of the liquid state of mW water results in a sharp irreversible drop in potential energy and large fluctuation in two and three body potential energy of the maximum size of four coordinated cluster. Further, we found the relaxation of liquid state of mW water associated with the sharp and continuous increase in the fraction of four coordinated particles as a function of temperature for different cooling rates. The predicted results of this study are consistent with the literature, which helps to understand the relaxation phenomena of mW water and other such thermodynamic systems more significantly.

Strong core and Pareto-optimality in the multiple partners matching problem under lexicographic preference domains

We study strong core and Pareto-optimal solutions for multiple partners matching problem under lexicographic preference domains from a computational point of view. The restriction to the two-sided case is called stable many-to-many matching problem and the general one-sided case is called stable fixtures problem. We provide an example to show that the strong core can be empty even for many-to-many problems, and that deciding the non-emptiness of the strong core is NP-hard. On the positive side, we give efficient algorithms for finding a near feasible strong core solution and for finding a fractional matching in the strong core of fractional matchings. In contrast with the NP-hardness result for the stable fixtures problem, we show that finding a maximum size matching that is Pareto-optimal can be done efficiently for many-to-many problems. Finally, we show that for reverse-lexicographic preferences the strong core is always non-empty in the many-to-many case.