bluuebunny/crossref_metadata_2025 huggingface dataset:
Exosomes and their possible applications in the management of gestational diabetes
Authors: Sibiak Rafał , Jaworski Michał , Barrett Saoirse , Bryl Rut , Gutaj Paweł , Wender-Ożegowska Ewa
Published: January 2021

Gestational diabetes mellitus (GDM) is thought to be the most common metabolic gestational complication. Its prevalence has been continuously increasing in recent decades along with the rising epidemic of obesity in modern societies. GDM is associated with an increased risk of fetal growth abnormalities, birth traumas, and several neonatal complications. Widely available screening tools, fasting glucose measurements, combined with oral glucose tolerance test results, contribute to the reduction of the risk of those complications. Nevertheless, we are still looking for novel reliable early markers of GDM. It has been established that high 1st-trimester exosome concentrations could predispose the development of GDM in later pregnancy. Exosomes can be easily isolated from various tissues and body fluids in pregnant patients. Due to this, extracellular vesicle concentration assessment appears as a new promising tool in the prediction of GDM at the preclinical stage of the disease. Furthermore, it has been found that women already diagnosed with GDM have significantly higher exosome concentrations compared with healthy individuals. These findings could help to elucidate the molecular pathogenesis of GDM. Exosomes are loaded with various molecules especially proteins, lipids, mRNAs, and microRNAs. Altered expression of numerous microRNAs and enzymes such as dipeptidyl peptidase-IV in exosomes isolated from patients with GDM may suggest their direct contribution to the mechanisms of glucose intolerance. This knowledge could be used in the development of new therapeutic strategies in patients with GDM. Nevertheless, it should be emphasized that these are only preliminary results that require further investigations.

Running title: Exosomes in gestational diabetes
Analysis of TGFB1, CD105 and FSP1 expression in human granulosa cells during a 7-day primary in vitro culture
Authors: Bryja Artur , Pieńkowski Wojciech , Stefańska Katarzyna , Chermuła Błażej , Bryl Rut , Wieczorkiewicz Maria , Kulus Jakub , Wąsiatycz Grzegorz , Bukowska Dorota , Ratajczak Kornel , Jaśkowski Jędrzej M. , Petitte James N. , Mozdziak Paul , Pawelczyk Leszek , Spaczyński Robert Z. , Antosik Paweł
Published: January 2021

The human granulosa cells (GCs) surround the oocyte and form the ovarian follicle’s proper architecture.

These sub-populations include mural granulosa cells, antral granulosa cells, and cumulus granulosa cells.

Their main functions are to support the oocyte’s growth (cumulus granulosa cells) and estradiol production (mural granulosa cells). After ovulation, the granulosa cells transform into the luteal cells of the corpus luteum and produce progesterone.

Our study investigated the expression profile of three genes: TGFB1, CD105, and FSP1 during a 7-day in vitro culture. The analysis was conducted using the RT-qPCR technique.

Changes in the expression of CD105 and FSP1 could be observed during the 7-day in vitro culture. In the case of TGFB, the expression remained at a similar level, with no statistically significant differences observed.

Running title: Expression of TGFB1, CD105 and FSP1 in granulosa cells
The influence of osteogenic differentiation on the stem-like properties of adipose derived stem cells – an RT-qPCR study
Authors: Bryl Rut , Dompe Claudia , Jankowski Maurycy , Stefańska Katarzyna , Narenji Afsaneh Golkar , Kulus Jakub , Kulus Magdalena , Wieczorkiewicz Maria , Wąsiatycz Grzegorz , Jaśkowski Jędrzej M. , Kaczmarek Mariusz , Petitte James N. , Mozdziak Paul , Antosik Paweł , Bukowska Dorota
Published: January 2021

ADSCs are readily accessible and widely available. Isolated through a minimally invasive procedure from adipose depots, they can be found at diverse body location, where they served various functions, including energy homeostasis. They can be obtained upon surgeries from otherwise waste tissues, like after excision of fat tissue or liposuction. In addition, due to the possibility to isolate many ADSCs, in vitro proliferation can be performed in a short time period, resulting in cells showing more predictable results[1]. For this study ADSCs were obtained from waste material following routing sterilization procedures of dogs. This study aimed to analyse the expression of MSC specific markers before and after in vitro differentiation of ASCs. Three positive and three negative markers were analysed, CD105, CD73, CD90, CD34, CD14 and CD45. There were significant differences detected in the expression of all of the genes, with most of them exhibiting notable downregulation. The only exception, CD14 showed major upregulation after the process of differentiation. These changes confirm the success of differentiation, as well as suggest that this process significantly lowers the stem-like ability of ASCs. This knowledge should serve as a reference for further molecular and clinical studies, possibly aiding the understanding of the internal mechanisms governing the differentiation and stemness of ASCs, to enable their widespread and safe application in regenerative medicine.

Running title: Mesenchymal markers during ASC osteogenic differentiation
Human placenta-derived stem cells - recent findings based on the molecular science
Authors: Sibiak Rafał , Jaworski Michał , Dorna Zuzanna , Pieńkowski Wojciech , Stefańska Katarzyna , Bryl Rut , Žáková Jana , Crha Igor , Ventruba Pavel , Ješeta Michal , Kempisty Bartosz
Published: January 2021

The human placenta is a complex, multifunctional transient fetomaternal organ. The placenta is composed of the maternal decidua basalis and its fetal part, consisting of the mesenchymal and trophoblast cell lineages. Both the placenta and the amniotic membranes are abundant in readily available placenta-derived mesenchymal stem cells (PD-MSCs). The clinical application of the PD-MSCs opens new perspectives for regenerative medicine and the treatment of various degenerative disorders. Their properties depend on their paracrine activity – the secretion of the anti-inflammatory cytokines and specific exosomes. In contrast to the PD-MSCs, the trophoblast stem cells (TSCs) are much more elusive. They can only be isolated from the blastocyst-stage embryos or the first-trimester placental tissue, making that procedure quite demanding. Also, other cultures require specific, strictly controlled conditions. TSCs may be potentially used as an in vitro model of various placental pathologies, facilitating the elucidation of their mysterious pathogenesis and creating the environment for testing the new drug efficiency. Nonetheless, it is unlikely that they could be ever implemented as a part of novel cellular therapeutic strategies in humans.

Running title: Current knowledge on the placental stem cells
Comparison of microfluidic and swim-up sperm separation methods for IVF
Authors: Ješeta Michal , Franzová Kateřina , Žáková Jana , Ventruba Pavel , Crha Igor
Published: January 2021

Sperm separation for ICSI is an essential step in realization of the IVF procedures. The method of microfluidic separation of sperm cells using chips has been applied more and more frequently in recent years. This method is often presented as extremely gentle to spermatozoa and decreasing significantly concentration of sperm cells with fragmented DNA when compared to conventional methods. The aim of our study was to verify a microfluidic chip system from the perspective of its potential to select spermatozoa with non-fragmented DNA. We tested the efficiency of this separation method against the swim-up method. In this study we evaluated sperm DNA integrity before and after the separation methods in ten patients. Ejaculate of each patient was separated by both the swim up method and the microfluidic chip method at the same time. It was shown that both the methods are very similar in reduction of spermatozoa with fragmented DNA. Interestingly, the concentration of spermatozoa with fragmented DNA was lower after the microfluidic separation than after the swim-up method in all the patients. Nevertheless, the differences were not statistically significant with only 2.1% on average, which is negligible in terms of practical use.

Running title: Microfluidic chip and DNA fragmentation
Expression of genes involved in the inflammatory response in human granulosa cells in short-term in vitro culture
Authors: Kałużna Sandra , Bryl Rut , Chermuła Błażej , Sibiak Rafał , Stefańska Katarzyna , Pieńkowski Wojciech , Kranc Wiesława , Jeseta Michal , Ventruba Pavel , Zakova Jana , Crha Igor , Pawelczyk Leszek , Spaczyński Robert Z.
Published: January 2021

The essential function of granulosa cells is to maintain the proper course of oogenesis and folliculogenesis.

The immune system is an additional local regulator of ovarian function, with cytokines necessary for the proper function of the ovaries, including the secretion of steroid hormones

This study aimed to analyze the expression of genes in human GCs in short-term primary culture and define the difference in the expression of IL1β, IL6, and TNFα genes at 48h and 72h of culture compared to the 24h control. Total RNA was isolated using the Chomczyński and Sacchi protocol. RNA samples were treated with DNase I and reverse transcribed (RT) into cDNA. The determination of transcript levels of the mentioned genes was performed using the Light Cycler® 96 Real-Time PCR kit, Roche Diagnostics GmbH (Mannheim, Germany).

The present study proved that granulosa cells in a short-term primary in vitro culture express IL-1β, IL-6, and TNFα. The tested genes show a decrease in expression at 24h of culture and a subsequent slight increase at 72h, not exceeding the initial levels. The expression changes the most for IL1β and the least for TNFα.

The fluctuations in the amount of transcript may be influenced by factors stored in granulosa cells before the IVM procedure, the procedure of in vitro fertilization, as well as factors related to the process of primary culture. More research is needed to understand the details of these occurrences.

Running title: The inflammatory response in human granulosa cells
Absolute Dating of the Systematic Excavation from 2019 of the Archaeological Site: Tărtăria-Gura Luncii (Alba County, Romania)
Authors: Luca Sabin Adrian , Rustoiu Gabriel T. , Perianu Florentin , Chideșa Sergiu , Sava Tiberiu Bogdan , Păceșilă Doru , Gaza Oana , Stanciu Iuliana , Sava Gabriela , Ștefan Bianca
Published: January 2021

The systematic research started in 2010 at Tărtăria continue to this day. To clarify the problem of the absolute chronology of the site we have researched on a checkered row (Carriage 25-32) from the SI surface (2019) and carried out sampling for this operation. On this occasion we obtained the evidence published in this article.
Ritual deposits of the Petrești culture in South-Western Transylvania
Authors: Luca Sabin Adrian
Published: January 2021

This article resents archaeological discoveries of ritual pits framed in Petrești culture, discovered in western and south-western Transylvania. The ritual of consecrating the dwellings, through banquets dedicated to fertility and fecundity, is so well known at the time around the Apuseni Mountains that is spreads in cultural environments, west of them.
At the Turn of the Fourteenth Century: Sigismund of Luxemburg and the Wallachian Princely “Stars” of the Fifteenth Century
Authors: Simon Alexandru
Published: January 2021

In late spring 1398, the noble judges of the Inner Szolnok County rejected John Toth as the legal representative of Stephen I, voivode of Moldavia. Toth (i.e. the Slav/ Slovak, chiefly in later centuries) was in fact merely the procurator of Stephen’s appointed procurator (representative), a certain John, the son of Costea. Mircea I the Elder, the voivode of Wallachia, was experiencing similar legal problems at the time in the Voivodate of Tran-sylvania. In January 1399, his procurator, Nicholas Dobokai of Luduş, the son of Ladislas Dobokai (the relative of Mircea’s step-uncle, Wladislaw I Vlaicu), had to admit he did not know the exact boundaries of the estate of the Hunyad castle, recently granted by Sigismund of Luxemburg to Mircea. The two documents, almost trivial in essence, point towards two neglected issues: the first Transylvanian estates granted by a king of Hungary to a voivode of Moldavia and to the transalpine origins of the Hunyadi family. Placed in the context of other edited and unedited sources (charters and chronicles), the documents in question provide new perspectives on the beginnings and actions of famed Wallachian personalities of the next century.
On Pull-Back Bundle of Tensor Bundles Defined by Projection of The Cotangent Bundle
Authors: Yildirim Furkan
Published: January 2021

Using projection (submersion) of the cotangent bundle T*M over a manifold M, we define a semi-tensor (pull-back) bundle tM of type (p,q). The aim of this study is to investigate complete lift of vector fields in a special class of semi-tensor bundle tM of the type (p,q). We also have a new example for good square in this work.
Some Properties of Diagonal Lifts in Semi-Cotangent Bundles
Authors: Akbulut Kursat , Yildirim Furkan
Published: January 2021

We analyze some properties of diagonal lift of tensor fields of type (1,1) in semi-cotangent bundles with the help of adapted frames.
Dichromatic polynomial for graph of a (2,n)-torus knot
Authors: Şahin Abdulgani
Published: January 2021

In this study, we introduce the relationship between the Tutte polynomials and dichromatic polynomials of (2,n)-torus knots. For this aim, firstly we obtain the signed graph of a (2,n)-torus knot, marked with {+} signs, via the regular diagram of its. Whereupon, we compute the Tutte polynomial for this graph and find a generalization through these calculations. Finally we obtain dichromatic polynomial lying under the unmarked states of the signed graph of the (2,n)-torus knots by the generalization.
On Some Integral Inequalities via Conformable Fractional Integrals
Authors: Akdemir Ahmet Ocak , Deniz Erhan , Yüksel Ebru
Published: January 2021

In the present note, we have given a new integral identity via Conformable fractional integrals and some further properties. We have proved some integral inequalities for different kinds of convexity via Conformable fractional integrals. We have also showed that special cases of our findings gave some new inequalities involving Riemann-Liouville fractional integrals.
Nonlinear optimization generating the Tomb Mural Blocks by GANS
Authors: Wu Meng , Payshanbiev Adim , Zhao Qing , Yang Wenzong
Published: January 2021

Tomb murals are the special kind of murals that are buried underground. Due to the narrow exit of the tomb passage, the tomb murals were excavated by dividing the whole mural into blocks, which made lots of information missing between the blocks. The digital restoration technology Image inpainting uses the edge information around the missing parts to spread the information inside of the defect area and fills the information from the outside to the inside. But it is not suitable for filling the missing parts between the tomb mural blocks. Because these parts are large for exemplar-based inpainting which may make texture dislocation and for PDE which may make cartoon blur. It is a need to generate the information outwards to complete the information. The generative adversarial network uses deep learning training by the murals remains to generate the information from inside to outside, but the typical GAN doesn‘t have a good nonlinear feature. This paper provided a generating technology based on the deep convolution generative adversarial network to rebuild the missing information between the tomb mural blocks. It built the training data set of the simulation platform with Keras and designed a whole mural generation scheme based on DCGAN. In order to get better generated results to avoid the bad artifacts; it adds the nonlinear layers by choosing 13 layers convolution and 2 deconvolution layers of the generator and contained 5 layers convolution discriminator; it designed a new phased nonlinear loss function by using Pycharm pretreatment for Numpy array file data sets; finally, it completed the generate tomb mural information to obtain the good simulation effect.
Computing Forgotten Topological Index of Extremal Cactus Chains
Authors: Cancan Murat , Imran Muhammad , Akhter Shehnaz , Siddiqui Muhammad Kamran , Hanif Muhammad Farhan
Published: January 2021

The F-index is the whole of 3D squares of vertex degrees in a chart G. It as of late turned into the subject of a few investigates because of its extraordinary capability of uses. The point of this paper is to register the F-record of triangular prickly plant chain, square desert flora chains, 6-sided cactus restraints and polyomino restraints. In addition, we decided the extremal chains in the desert plant chains and polyomino fastens as for the F-index.
Periodic orbits in the restricted problem of three bodies in a three-dimensional coordinate system when the smaller primary is a triaxial rigid body
Authors: Poddar Awadhesh Kumar , Sharma Divyanshi
Published: January 2021

In this paper, we have studied the equations of motion for the problem, which are regularised in the neighbourhood of one of the finite masses and the existence of periodic orbits in a three-dimensional coordinate system when μ = 0. Finally, it establishes the canonical set (l, L, g, G, h, H) and forms the basic general perturbation theory for the problem.
Research on style control in planning and designing small towns
Authors: Hu Xing , Li Jinhua , Aram
Published: January 2021

With the rapid development of extensive urbanisation in the pursuit of refined quality, the management and control of architectural features in small towns have become more and more prominent, especially in the period when the planning system is nearly complete. Most small towns are still in the low efficiency or lack of the environment has become an important obstacle to the inheritance of traditional architectural style and the shaping of individual characteristics in small towns. How to provide a refined, comprehensive and efficient building style management and control system for managers, planners and subsequent architectural designers is particularly important for reversing the current disadvantages of small town style management and control. This article is problem-centred and conducts in-depth analysis from the aspects of style control ideas and style division control, trying to find a practical way of urban style control, hoping to benefit the urban development in the modernisation boom.
Some Characterizations of Neutrosophic Submodules of an R-module
Authors: Binu R. , Isaac Paul
Published: January 2021

In this paper, we investigate some new characterizations in the algebraic nature of neutrosophic submodule defined over a classical module using single valued neutrosophic set. We additionally characterized the neutrosophic point and determined the algebraic properties of neutrosophic point using the operations defined on neutrosophic submodule. Finley we examined a neutrosophic set as a generator of a neutrosophic submodule and derived some related concepts.
Periodic solutions for differential systems in ℝ3 and ℝ4
Authors: Feddaoui Amina , Llibre Jaume , Berhail Chemseddine , Makhlouf Amar
Published: January 2021

We provide sufficient conditions for the existence of periodic solutions for the differential systems

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\matrix{{x' = y,\;\;\;y' = z,\;\;\;z' = - y - \varepsilon F(t,x,y,z),\;\;\;{\rm{and}}} \cr {x' = y,\quad y' = - x - \varepsilon G(t,x,y,z,u),\quad z' = u,\quad u' = - z - \varepsilon H(t,x,y,z,u),} \hfill \cr }

where F, G and H are 2π–periodic functions in the variable t and ɛ is a small parameter. These differential systems appear frequently in many problems coming from the sciences and the engineering.
Identification of sex using discriminant function analysis of fingerprint ridge density at three topological areas among North Indian population
Authors: Kaur Maninder , Kaur Mankamal , Yangchan Jigmath
Published: January 2021

The present study attempted to identify sex of an individual using a fingerprint ridge density at three topological areas in the North Indian population. The study population consisted of 134 males and 136 females aged 17 to 25 years (mean age 19.34±2.12). Ridge density (RD) at radial, ulnar and proximal topological areas of the distal phalanges were determined on the surface area of 25mm2. Fingerprint ridge density in a defined area was significantly higher among females as compared to their male counterparts at radial, ulnar and proximal topological areas for both hands. Sexual dimorphic ratio also supported this trend for all three counting areas in right and left hands. Univariate discriminant function analysis explained that the left 2 radial (L2R) (88.1%) had the highest percentage of accuracy for sex identification, followed by the left 3 ulnar (L3U) (82.1%) and the right 2 ulnar (R2U) (81.6%). Multivariate discriminant function analysis showed that the radial topological area of the left hand was the best predictor of sex with the overall accuracy of 84.4%with following discriminant function equation −8.263 − 0.236(L1R) + + 0.321(L2R) + 0.269(L3R) + 0.268(L4R) − 0.067(L5R).

It can be inferred that ridge density in the radial topological area of left hand is the most reliable tool for identifying the sex of an individual.
Assessment of Nutritional Status and Body Composition in Tibetan Adolescent girls of Kangra district, Himachal Pradesh
Authors: Singh Shweta , Singh Neelam , Kshatriya Gautam K.
Published: January 2021

Malnutrition among adolescents is an important public health issue in India. The aim of the present study was to assess nutritional status and body composition characteristics of adolescent girls and their interrelationships with physical activity and socioeconomic status (SES). Nutritional status and body composition characteristics were assessed in terms of body mass index (BMI), upper arm muscle area by height (UAMAH) and percent body fat (PBF) among 276 Tibetan adolescent girls from Kangra district, Himachal Pradesh. Overall, 12.7% of the girls were in the wasting category (using Z-score based classification for UAMAH) and 9.8% were thin. About 16.3% girls were obese. Significant variabilities of PBF have been observed with respect to age and levels of physical activity and wasting. Adolescent girls were observed to have higher lean body mass than body fat.
Dread in Academia – how COVID-19 affects science and scientists
Authors: Kowal Marta , Sorokowski Piotr , Sorokowska Agnieszka , Lebuda Izabela , Groyecka-Bernard Agata , Białek Michał , Kowalska Kaja , Wojtycka Lidia , Olszewska Alicja M. , Karwowski Maciej
Published: January 2021

In order to gain an insight into scholars’ concerns emerging from the COVID-19 crisis, we asked scientists from all over the world about their attitudes and predictions regarding the repercussions of this current crisis on academia. Our data showed that the academic world was placed in an unprecedented situation. Results further showed that everybody worked on-line, conducting studies was impossible or highly impeded, and lab work was difficult. Almost a quarter of all scientists participating in our survey were anxious about their scientific employment, and over 25% expected serious financial losses as a consequence of the pandemic. Moreover, we identified sex differences regarding the severity of the COVID-19 impact in the majority of questions. We inferred from this that women perceived to be in a worse situation than men.
From gerontology to geroscience: a synopsis on ageing
Authors: Chmielewski Piotr Paweł
Published: January 2021

Biological ageing can be tentatively defined as an intrinsic and inevitable degradation of biological function that accumulates over time at every level of biological organisation from molecules to populations. Senescence is characterised by a progressive loss of physiological integrity, leading to impaired function and increased vulnerability to death. With advancing age, all components of the human body undergo these cumulative, universal, progressive, intrinsic and deleterious (CUPID) changes. Although ageing is not a disease per se, age is the main risk factor for the development of a panoply of age-related diseases. From a mechanistic perspective, a myriad of molecular processes and components of ageing can be studied. Some of them seem especially important and they are referred to as the hallmarks of ageing. There is compelling evidence that senescence has evolved as an emergent metaphenomenon that originates in the difficulty in maintaining homeodynamics in biological systems. From an evolutionary perspective, senescence is the inevitable outcome of an evolutionarily derived equilibrium between the amount of resources devoted to somatic maintenance and the amount of resources devoted to sexual reproduction. Single-target, single-molecule and disease-oriented approaches to ageing are severely limited because they neglect the dynamic, interactive and networking nature of life. These limitations notwithstanding, many authors promote single-target and disease-oriented approaches to senescence, e.g. repurposed drugs, claiming that these methods can enhance human health and longevity. Senescence is neither a disease nor a monolithic process. In this review, the limitations of these methods are discussed. The current state of biogerontology is also summarised.
Relationship between bone density of paranasal sinuses and adrenal steroids pattern in women during menopausal transition
Authors: Gargin Vitaliy , Muryzina Iryna , Shcherbina Nikolay , Nechyporenko Alina , Baryshevska Victoria , Vorobyova Olga , Alekseeva Victoriia
Published: January 2021

The course of menopause transition (MT) is associated with peculiarities of alterations occurring in a woman’s body, in particular, in the structure of bone tissue. Considering that bones of the paranasal sinuses (BPNSs) play a natural defense role against the spread of dental infection, their structure is important in dentistry. However, no information was found pertaining to changes of BPNSs during MT – a time when dental maladies increase in many women.

The aim of our study was to collate density of BPNSs with status of adrenal steroids in women during MT, since the pattern of their changes determines the course of MT.

Cross-sectional associations were examined between bone density of PNSs assessed by Spiral Computed Tomography and Serum content of testosterone (T), sex hormone binding globulin (SHBG), free androgen index (FAI), insulin, dehydroepiandrosterone sulfate (DHEAS), Adione, and Adiol in 113 women of per­imenopausal age (age range from 45 to 55 years) who had already experienced premenopausal menstrual decline (amenorrhea less than 2 years).

Strong positive (r = 0.73) correlation between minimal bone density of maxillary sinus in women with level of DHEAS was detected. It is important to note, that the correlation between minimal density of the lower wall of frontal sinus is a weak positive (0.3). Therefore , it can be suggested that bone tissue of the maxillary sinus is more sensitive to changes in DHEAS.

The study showed that the level of male steroids, in particular DHEAS, affected the state of bone tissue in participants older than 50 years of age.
Social position in a peer group of school-aged boys and selected biological parameters
Authors: Kulik Tomasz , Kozieł Sławomir
Published: January 2021

The period of adolescence includes biological, psychological and social maturation. All these processes complement and affect each other. The ultimate goal is the transition from childhood to adulthood which enables individuals to become socialized beings, who are psychologically mature and able to pass on their genetic inheritance. In the process of reaching full maturity, adolescents are exposed to both positive and negative stimuli the socio-cultural environment. In the process of socialization, the influence of peers, and the maturing into social roles is important. At the same time, adolescents mature biologically. A holistic understanding of the sequence of changes that occur during adolescence foregrounds the significance of biology in informing emotions and cognition. Research conducted on adolescents from Wrocław, Poland, showed the impact that physical development plays on social development within a school peer group. Adolescents with a slower pace of maturity, lower BMI, and lower body height achieved the lowest social status in the group’s hierarchy. These adolescents also became victims of peer rejection. The role of scapegoat assigned to them highlighted and completed the symptomatic rejection process, which highlighted negative social group behaviours. In contrast, their peers from the same classes, with higher biological parameters, became leaders in the school’s social groups. Furthermore, sociometric ‘stars’, leaders and gray eminences, compared to scapegoats, achieved maturity faster, and had greater body height and higher BMI among all age groups.
Assessment of GNSS PPP-Based Zenith Tropospheric Delay
Authors: Abdelazeem Mohamed , El-Rabbany Ahmed
Published: January 2021

This study assesses the precision of zenith tropospheric delay (ZTD) obtained through triple-constellation global navigation satellite system (GNSS) precise point positioning (PPP). Various ZTD estimates are obtained as by-products from GPS-only, GPS/Galileo, GPS/BeiDou, and triple-constellation GPS/Galileo/BeiDou PPP solutions. Triple-constellation GNSS observations from a number of globally distributed reference stations are processed over a period of seven days in order to investigate the daily performance of the ZTD estimates. The estimated ZTDs are then validated by comparing them with the International GNSS Service (IGS) tropospheric products and the University of New Brunswick (UNB3m) model counterparts. It is shown that the ZTD estimates agree with the IGS counterparts with a maximum standard deviation (STD) of 2.4 cm. It is also shown that the precision of estimated ZTD from the GPS/Galileo and GPS/Galileo/BeiDou PPP solutions is improved by about 4.5 and 14%, respectively, with respect to the GPS-only PPP solution. Moreover, it is found that the estimated ZTD agrees with the UNB3m model with a maximum STD of 3.1 cm. Furthermore, the GPS/Galileo and GPS/Galileo/BeiDou PPP enhance the precision of the ZTD estimates by about 6.5 and 10%, respectively, in comparison with the GPS-only PPP solution.
Automatic Detection of Dominant Crop Types in Poland Based on Satellite Images
Authors: Pluto-Kossakowska Joanna , Pilarska Magdalena , Bartkowiak Paulina
Published: January 2021

The assumption of the European Union Common Agricultural Policy is to maintain good agricultural practices for sustainability in the environment. A number of requirements are imposed on farmers, including the maintenance of permanent grassland, fallow land or crop diversification. To meet these requirements, the European Union guarantees subsidies, but at the same time fields must be monitored focusing on crop identification. The limitation of field inspection and substituting it with crop recognition using satellite images could increase the effectiveness of this procedure. The application of satellite imagery in automatic detection and identification of dominant crops over a large area seems to be technically and economically sound. The paper discusses the concept and the results of automatic classification based on a Random Forests classifier performed on multitemporal images of Sentinel-2 and Landsat-8. A test site was established in a complex agricultural structure with long and narrow parcels in the south-eastern part of Poland. Time-series images acquired during the growing season 2016 were used for multispectral classification in different configurations: for Sentinel-2 and Landsat-8 separately and for both sensors integrated. Different Random Forests approaches and post-processing methods were examined based on independent data from farmers’ declarations records, reaching the best accuracy of over 90% for crops like winter or spring cereals. Overall accuracy of the classification ranged from 72% to 91% depending on the classification variant. The elaborated scheme is novel in the context of Polish complex agricultural structure and smallholders.
A New Model of Dynamic Logic Circuit with NMOS based Keeper
Authors: Islam Riazul , Biswas Satyendra N.
Published: January 2021

Dynamic logic circuits are widely popular due to a smaller number of transistors and consume less area. But the time to switch between logics is higher due to higher contention value. A new model of the logic using nMOS based keeper circuit is proposed and the performance is evaluated using Cadence tools. Comparative results demonstrate the suitability and competency of the proposed circuit.
Generation of PWM Based on Simple Relay Feedback Systems
Authors: Zaatri Abdelouahab , Kelaiaia Ridha
Published: January 2021

This paper is concerned with the analysis of the tracking capability of Relay Feedback Control Systems (RFCS). The envisioned application is the generation of Pulse-Width-Modulation (PWM) with variable duty-cycle and frequency known also as Duty-Cycle Modulation. In general, two main issues have to be solved with RFCS when used for regulation and tracking. The first issue concerns the determination of autonomous self-oscillations which are generated by the closed loop. The second issue concerns the determination of the relationship between the reference and the output signals. However, if the first issue has beneficiated from different approaches and has been solved particularly in case of zero reference signal, the second issue has got insufficient theoretical results because of mathematical difficulties for obtaining analytical expressions. Considering these reasons, a deep analysis of RFCS constituted of a hysteretic relay and linear systems of first order is presented. Analytical expressions relating self-oscillations and output mean values with respect to the reference signals are obtained. The analysis of these relationships led to infer some conditions under which the relay feedback control can generate commands for regulating and tracking reference signals. It highlights also the key role played by the hysteresis band width for applications based on RFCS. Our analysis, exploiting the analytical expressions, can be used to achieve a complete design for power converters. Moreover, simulation and experiments have confirmed our results.
Model-Based Control Strategy for Autonomous Vehicle Path Tracking Task
Authors: Reda Ahmad , Vásárhelyi József
Published: January 2021

Despite the advanced technologies used in recent years, the lack of robust systems still exists. The automated steering system is a critical and complex task in the domain of the autonomous vehicle’s applications. This paper is a part of project that deals with model-based control strategy as one of the most common control strategies. The main objective is to present the implementations of Model Predictive Control (MPC) for an autonomous vehicle steering system in regards to trajectory tracking application. The obtained results are analysed and the efficiency of the use of MPC controller were discussed based on its behaviour and performance.
The Impact of Integrated Maintenance Actions Optimization on Strategic Machines Lifetime
Authors: Bensaci Mohammed Abdellatif , Hadjadj Aoul Elias
Published: January 2021

This article is based on the quantitative study of reliability, maintainability, availability (RMA), on the Pareto diagram (ABC) and on the analysis of the failure modes and their impact on criticality (FMECA). The developed approach aims, at first, implementing two optimization procedures (code development, Simulink modelling in MATLAB) and using two methods (graphical, analytic) of the Weibull parameters. The results obtained via code (which is based on the Weibull graph method of two parameters) are a bit divergent. The evaluation criteria are rather far from that of the model (which is based on the maximum likelihood of three-parameter Weibull distribution). This will allow to locate the critical elements, and to determine the systematic preventive time of replacements. An application case validates the proposed study objective.
Study of Reliability in a Repairable System by Markov Chains
Authors: Tamaloussi Naima , Bouzaouit Azzedine
Published: January 2021

In the industrial sector, maintenance of production facilities plays an important role to carry out production by increasing the reliability and availability of the production process. Predictive maintenance strategy seems adequate to anticipate the failure and degradation of the state of such equipment. A reliability study is needed to quantify indicators to describe the functioning of any system over time. In this paper, we present the results of a stochastic modeling conducted on the analysis of the availability of motor-pump system, installed in a cooling circuit in an industrial complex. The equipment considered in this study is composed of four subsystems. The proposed model is a dynamic Markovian approach, for the purpose of a comparison with the analytical calculation in terms of the indicators’ evaluation of the dependability of the studied system, including instant availability. The different states of the system components and the transition functions between these states have also been characterized. The results of availability obtained by the model are well correlated with those calculated analytically, confirming that the proposed model is very powerful, it will help predict the future states of the system, in order to predict any necessary preventive maintenance actions.
Improvement of the Hammer Drill Performance (Algerian Quarries Conditions)
Authors: Nemouchi Samia , Aoul Elias Hadjadj
Published: January 2021

The factors which influence the performance characteristics of a hammer drill are examined; drilling data are analyzed to determine these factors. Methods for selecting the appropriate drilling are also highlighted. Two models are used in order to compare optimal drilling parameters. The main one is the machine output.
Preface
Authors: Karaivanova Aneta , Margenov Svetozar
Published: January 2021

We are pleased to present the special issue “New developments in scalable computing” of the scientific journal “Cybernetics and Information Technologies”. For this issue (Volume 20, No 6 – December 2020), we have selected 19 papers which have gone through peer review and represent novel results in the field of Scalable Computing using state-of-the-art high-performance computing infrastructures.
Performance Optimization System for Hadoop and Spark Frameworks
Authors: Astsatryan Hrachya , Kocharyan Aram , Hagimont Daniel , Lalayan Arthur
Published: January 2021

The optimization of large-scale data sets depends on the technologies and methods used. The MapReduce model, implemented on Apache Hadoop or Spark, allows splitting large data sets into a set of blocks distributed on several machines. Data compression reduces data size and transfer time between disks and memory but requires additional processing. Therefore, finding an optimal tradeoff is a challenge, as a high compression factor may underload Input/Output but overload the processor. The paper aims to present a system enabling the selection of the compression tools and tuning the compression factor to reach the best performance in Apache Hadoop and Spark infrastructures based on simulation analyzes.
New Uniform Subregular Parallelisms of PG(3, 4) Invariant under an Automorphism of Order 2
Authors: Betten Anton , Topalova Stela , Zhelezova Svetlana
Published: January 2021

A spread in PG(n, q) is a set of lines which partition the point set. A parallelism is a partition of the set of lines by spreads. A parallelism is uniform if all its spreads are isomorphic. Up to isomorphism, there are three spreads of PG(3, 4) – regular, subregular and aregular. Therefore, three types of uniform parallelisms are possible. In this work, we consider uniform parallelisms of PG(3, 4) which possess an automorphism of order 2. We establish that there are no regular parallelisms, and that there are 8253 nonisomorphic subregular parallelisms. Together with the parallelisms known before this work, this yields a total of 8623 known subregular parallelisms of PG(3, 4).
Two-Stage Search-Based Approach for Determining and Sorting of Mountain Hiking Routes Using Directed Weighted Multigraph
Authors: Dimitrova Zornitsa , Dimitrov Vasil , Borissova Daniela , Garvanov Ivan , Garvanova Magdalena
Published: January 2021

The mountain hiking destinations become more popular as this is one of the possible ways to cope with workplace stress and to prevent burnout. In contrast to the tourist destinations, mountain hiking requires special attention due to the variety of mountain trails satisfying the same starting and finishing point for a particular route. For the goal, a two-stage search-based approach for a determining of possible routes considering the users’ preferences is developed. The first stage is focused on the determining of possible hiking routes taking into account the requirements and tourists’ preferences, while the second stage concerns the sorting of already determined hiking routes. The applicability of the described approach is illustrated and the obtained results demonstrate the capability in searching and sorting of mountain hiking trails using directed weighted multigraph including tourists’ preferences.
New Local Search Procedure for Workforce Planning Problem
Authors: Fidanova Stefka , Luque Gabriel
Published: January 2021

Optimization of workforce planning is important for any production area. This leads to an improvement in production process. The aim is minimization of the assignment costs of the workers, who will do the jobs. The problem is to select and assign employers to the jobs to be performed. The constraints are very strong, coming both from the specifics of the production process and from the legislation. Sometimes it is difficult to find feasible solutions. The complexity of the problem is very high and the needed number of calculations is exponential, therefore only specially developed algorithms can be applied. The objective is to minimize the assignment cost, while respecting all requirements. We propose a new hybrid metaheuristic algorithm to solve the workforce-planning problem, which is a combination between Ant Colony Optimization (ACO) and suitable local search procedure.
Performance Analysis of a Scalable Algorithm for 3D Linear Transforms on Supercomputer with Intel Processors/Co-Processors
Authors: Lirkov Ivan
Published: January 2021

Practical realizations of 3D forward/inverse separable discrete transforms, such as Fourier transform, cosine/sine transform, etc. are frequently the principal limiters that prevent many practical applications from scaling to a large number of processors. Existing approaches, which are based primarily on 1D or 2D data decompositions, prevent the 3D transforms from effectively scaling to the maximum (possible/available) number of computer nodes. A highly scalable approach to realize forward/inverse 3D transforms has been proposed. It is based on a 3D decomposition of data and geared towards a torus network of computer nodes. The proposed algorithms requires compute-and-roll time-steps, where each step consists of an execution of multiple GEMM operations and concurrent movement of cubical data blocks between nearest neighbors. The aim of this paper is to present an experimental performance study of an implementation on high performance computer architecture.
On Dynamic Parallelization of Multilevel Monte Carlo Algorithm
Authors: Shegunov Nikolay , Iliev Oleg
Published: January 2021

MultiLevel Monte Carlo (MLMC) attracts great interest for numerical simulations of Stochastic Partial Differential Equations (SPDEs), due to its superiority over the standard Monte Carlo (MC) approach. MLMC combines in a proper manner many cheap fast simulations with few slow and expensive ones, the variance is reduced, and a significant speed up is achieved. Simulations with MC/MLMC consist of three main components: generating random fields, solving deterministic problem and reduction of the variance. Each part is subject to a different degree of parallelism. Compared to the classical MC, MLMC introduces “levels” on which the sampling is done. These levels have different computational cost, thus, efficiently utilizing the parallel resources becomes a non-trivial problem. The main focus of this paper is the parallelization of the MLMC Algorithm.
Geometrically Non-Linear Vibration of a Cantilever Interacting with Rarefied Gas Flow
Authors: Shterev Kiril , Manoach Emil
Published: January 2021

The work is devoted to study 2D pressure driven rarefied gas flow in a microchannel having an elastic obstacle. The elastic obstacle is clamped at the bottom channel wall and its length is half of the channel height. The gas flow is simulated by Direct Simulation Monte Carlo (DSMC) method applying the advanced Simplified Bernoulli Trial (SBT) collision scheme. The elastic obstacle is modelled as geometrically nonlinear Euler Bernoulli beam. A reduced 3 modes reduction model of the beam is created. The influence of the gas flow on the beam vibration is studied, considering the linear and nonlinear beam theories.
Molecular Dynamics Simulations of Acetylcholinesterase – Beta-Amyloid Peptide Complex
Authors: Atanasova Mariana , Dimitrov Ivan , Ivanov Stefan
Published: January 2021

Alzheimer’s Disease (AD) is a neurodegenerative disorder with severe consequences and lethal outcome. One of the pathological hallmarks of the disease is the formation of insoluble intercellular beta-Amyloid (Aβ) plaques. The enzyme ACetylcholinEsterase (AChE) promotes and accelerates the aggregation of toxic Aβ protofibrils progressively converted into plaques. The Peripheral Anionic Site (PAS), part of the binding gorge of AChE, is one of the nucleation centers implicated in the Aβ aggregation. In this study, the Aβ peptide was docked into the PAS and the stability of the formed complex was investigated by molecular dynamics simulation for 1 μs (1000 ns). The complex was stable during the simulation. Apart from PAS, the Aβ peptide makes several additional contacts with AChE. The main residence area of Aβ on the surface of AChE is the region 344-361. This region is next to PAS but far enough to be sterically hindered by dual-site binding AChE inhibitors.
Trend Analysis of CMIP5 Ensemble of Climate Indices over Southeast Europe with Focus on Agricultural Impacts
Authors: Chervenkov Hristo , Gadzhev Georgi , Ivanov Vladimir , Ganev Kostadin
Published: January 2021

Nowadays there is a strong degree of agreement that the climate change is the defining challenge of our time, which will exert influence on the ecosystems, on all branches of the international economy and on the quality of life. The analysis based on climate indices is widely used non-parametric approach for quantification of the mean state as well as extreme climate events. This study, which is continuation of our previous efforts, is dedicated to the assessment of the trend magnitude and the trend statistical significance of six temperature-based and three precipitation-based indices in projected future climate over Southeast Europe up to the end of the 21st century. The indices are computed from the bias-corrected output of five CMIP5 global models, reinforced with all four RCP emission scenarios. The model output is accessed from the section of the Inter Sectoral Impact Model Intercomparison Project in the Copernicus Data Store. The multi model ensemble medians of the temperature-based indices shows considerable increase which is consistent with the warming of the mean temperatures. These changes are statistically significant in most cases and intensify with the radiative forcing. The revealed tendencies of the precipitation-based indices are more complex when compared with temperature tendencies.