bluuebunny/crossref_metadata_2025 huggingface dataset:
Determinants of maternal near miss among women admitted to maternity wards of tertiary hospitals in Southern Ethiopia, 2020: A hospital-based case-control study
Authors: Habte Aklilu , Wondimu Merertu
Published: May 2021

Background

A maternal near-miss (MNM) refers to when a gravely ill woman survives a complication as a result of the standard of care she receives or by chance during gestation, childbirth, or within 42 days of the termination of pregnancy. Rescuers of near-miss events share several features with mothers who have died and identifying MNM determinants will aid in improving the capacity of the health system to reduce severe maternal morbidity and mortality. Ethiopia is one of the countries in sub-Saharan Africa with high maternal mortality and morbidity, but there is little evidence on determinants of a MNM based on a WHO criteria. Hence, this study aimed at identifying determinants of MNM among women admitted to tertiary hospitals in southern Ethiopia, 2020.

Methods

A facilities-based unmatched case-control study was conducted in five selected tertiary hospitals found in central southern Ethiopia from February 1 to June 1, 2020. A total of 322 (81 cases and 241 controls) study participants were included in the study. At the time of their discharge, cases were recruited consecutively, while controls were selected using a systematic sampling method. The cases were women admitted to hospitals during pregnancy, childbirth, or 42 days following termination of pregnancy who met at least one of the WHO near-miss criteria. Whereas the controls comprised of women who were admitted during pregnancy, childbirth, or 42 days following termination of pregnancy and discharged without severe obstetric complications. Data collection was conducted using the interviewer-administered structured questionnaire and data abstraction tool. The data was coded and entered into Epi-Data version 3.1 and exported to SPSS version 23 for analysis. Multivariable logistic regression analysis was conducted and determinants of MNM were established at p-value<0.05.

Results

Severe postpartum hemorrhage (50.6%) and sepsis (23.4%) were the most common reasons for admission of cases. Lack of ANC [AOR = 3.25; 95%CI: 2.21,7.69], prior history of Cesarean section [AOR = 3.53; 95%CI:1.79,6.98], delaying more than 60 minute to access final place of care [AOR = 3.21; 95%CI:1.61,6.39], poor practice of Birth preparedness and complication readiness (BPCR) [AOR = 3.31; 95%CI:1.50,7.29], and history of preexisting medical disorders [AOR = 2.79; 95%CI:1.45,5.37] were identified as significantly determinants of maternal near miss.

Conclusion and recommendation

Stakeholders need to enhance their efforts for improving access to roads and transportations. Besides, women who have a prior history of Caesarean section, chronic medical conditions, and no ANC need special attention from their families and health care providers to proactively mitigate the occurrence of serious obstetric complications. More attention has to be paid to birth preparedness and complication readiness activities.
Non-Vital Root Submergence for Preservation of Socket in an Adolescent - A Rare Case Report
Authors: Padmawar Neeta S. , Mustilwar Rachita G. , Mopagar Viddyasagar P. , Joshi Sourabh R. , Vadvadgi Vinay H. , Pendyala Gowri
Published: May 2021

Complex crown root fracture has been reported to be 5 % among the traumatic injuries to permanent teeth. In children, when fracture line extended sub gingivally, the treatment option remained was the extraction of tooth. This extraction led to alveolar bone loss and compromised the outcome of final prosthesis. Root submergence is one of the treatments options which can prevent bone loss and prepare future pontic site in a better way. In children, this technique can prevent not only bone loss but also the occurrence of space loss and development of tongue thrusting habit. Crown-root fracture is defined as a fracture involving enamel, dentin and cementum. It is reported in about 5 % of dental trauma to young children where root completion has not occurred.1 Treatment of these complex tooth fractures in aesthetic zone in growing age is always challenging for the paedodontists. The treatment should not interfere with the growth and development. Depending upon the extension of the fracture line which can result in exposure of the pulpal tissue, the crown-root fracture can be divided into two groups: complicated and uncomplicated. 2 Treatment options in cases of complicated crownroot fractures are complex, and require a multidisciplinary approach. Dental traumatology guideline and American Academy of Paediatric Dentistry has suggested fragment reattachment, orthodontic or surgical extrusion of apical portion followed by post placement, root submergence and extraction. 3 Factors like extension and direction of fracture line, pulpal involvement, tooth maturity and the length of root remaining in the alveolus govern the treatment choice. 4,5 Among above mentioned factors, position of facture line is the most important. As in case of subgingival facture line, risk of bacterial contamination is present and further this may result in gingival inflammation.6 When crown root fracture to permanent tooth occurs in mixed dentition period, goals of treatment are to preserve the tooth in arch without disturbing the growth & development of root and arch. But in case of complicated crown root fracture, when extraction is the only choice of treatment, future complications like space loss, crowding, habits like tongue thrusting and importantly loss of alveolar bone height should be kept in mind. Goals of treatment plan in such cases should be elimination of space loss, development of deleterious habit and maintenance of alveolar ridge for future pontic or implant site. Root submergence is the technique with which we can achieve these goals, keeping this in mind this case was planned and reported.
Universal Design as a Paradigm for Providing Health Interventions for Older Adults 1
Authors: Snyder Peter J.
Published: May 2021

Universal Design is a broadly applied approach within the industrial design (ID) field that has, as its hallmark characteristic, the goal of inclusivity. This design philosophy allows the ID professional to play a role as an extended member of the caregiving team for older adults by creating products, services and solutions with a design ethic that has direct effects on their health and well-being.
Pregnancy with Hypothyroid Secondary to Treatment of Thyroid Carcinoma: A Case Report
Authors: Udjaja Claudio , Pramono M. Besari Adi
Published: May 2021

Background: Thyroid malignancy is one of the most common malignancies in women of reproductive age. One of the normal physiological change in pregnancy is an increase in total maternal thyroid levels. According to 2015 DATIN information, the prevalence of hypothyroidism in women of reproductive age was 2.2%. Method of delivery in patients with thyroid disorders are mostly by cesarean section due to complications of the mother and/or fetus. Fetal outcome usually associated with low birth weight and poor APGAR Score.Objective : Reporting a case of pregnancy with hypothyroidism secondary to thyroid carcinoma treatmentCase: A 37-year-old woman Gravida 3 Parity 2 Abortion 0 with 18 weeks pregnancy after thyroid ablation treatment with a history of Papillary Thyroid Carcinoma – Follicular Variant, following a complete thyroidectomy in August 2016. The patient was given 6-dose ablation therapy, the last therapy was performed in April 2019. On clinical examination, the patient have no sign and symptoms suggesting hypothyroidism. On laboratory examination, the thyroid stimulating hormone (TSH) level was increased. Levothyroxine dosage was adjusted until the patient in euthyroid status in the early 3rd trimester of pregnancy until the delivery period. The fetal examination suggests that the Bio-Physical Profile was normal according to gestational age. The patient underwent vaginal delivery following 38 weeks of gestation with good maternal outcomes and low birth weight neonatal outcomes, no thyroid nodules, and slightly increased thyroid function.Conclusion : Management of counselling about preconception, contraception, and initial screening of patients with a history of thyroid carcinoma are the initial steps to help a better outcome in pregnancies with thyroid disorders.
MWMOTE optimization for imbalanced data using complete linkage
Authors: Untoro Meida Cahyo
Published: May 2021

Imbalanced data can result in classification errors, such as in WMMOTE, and can decrease its performance and accuracy. Clustering in MWMOTE can be optimized to improve synthetic data generation and improve MWMOTE performance. This study aims to optimize the MWMOTE algorithm's performance in the clustering process in making synthetic data with complete linkage (CL). The dataset used a variety of data ratios to handle imbalanced data. The decision tree was used to determine the performance of MWMOTE and CL-MWMOTE oversampling. CL-MWMOTE evaluation results provide better and optimal performance than MWMOTE and increase the precision, recall, f-measure, and accuracy of 0.53 %, 0.67 %, 0.66 %, and 0.67 %, respectively.
GENDER STEREOTYPES PRESENTED IN POPULAR CHILDREN’S FAIRY TALES
Authors: PAWŁOWSKA JOANNA
Published: May 2021

The article aims to contribute to the discussion on gender stereotypes in stories for children by mapping gender stereotypes in traditional fairy tales. The article presents fairy tales' value in children’s education and indicates potential dangers in traditional cultural transmissions, paying special attention to gender stereotypes. A selection of texts was analyzed in terms of their stereotypical gender portrayals. The methodological framework represents an interpretative paradigm in social sciences, using a qualitative method of analysis. The texts were purposely selected, and the most popular fairy tales were chosen: Cinderella, Snow White and Sleeping Beauty, which despite the passing of time, are still popular, widely read and also used in film adaptations. It was shown that in all analyzed fairy tales, there was a stereotypical division of roles according to gender. The article also presents possible ways to counteract gender stereotypes. A limitation of the article is that the analysis is limited to three fairy tales only, but the overarching value raises awareness of gender stereotypes in fairy tales for children.
JOHN B. SIMON, STRANGERS IN A STRANGER LAND
Authors: BERNHEIM MARK
Published: May 2021

This is a book review of "STRANGERS IN A STRANGER LAND: How One Country's Jews Fought an Unwinnable War Alongside Nazi Troops…and Survived"; by John B. Simon; Rowman and Littlefield; 2019 (originally published in Finnish as Mahdoton sota, "The Impossible War," by Siltala Publishing, 2017).

The review was written for the Jewish Book Council by a Professor Emeritus of English and contains both historical and pedagogical reflections on the educational messages emmerging from the book. This is important not only for memory studies and for identity politics but also when looking deep into the complex issues of socialization and education after the WWII. The book contains a story of the contradictory role of Finland's Jewish community in the wars against the Soviet Union and Germany.
Infinitely Many Solutions for the Nonlinear Schrödinger–Poisson System with Broken Symmetry
Authors: Guo Hui , Wang Tao
Published: May 2021

In this paper, we consider the following Schrödinger–Poisson system with perturbation:

{

-

Δ
⁢
u

+
u
+

λ
⁢
ϕ
⁢

(
x
)

⁢
u

=

|
u
|

p
-
2

⁢
u

+

g
⁢

(
x
)

,

x
∈

ℝ
3

,

-

Δ
⁢
ϕ

=

u
2

,

x
∈

ℝ
3

,

\left\{\begin{aligned} \displaystyle-\Delta u+u+\lambda\phi(x)u&\displaystyle=% |u|^{p-2}u+g(x),&&\displaystyle x\in\mathbb{R}^{3},\\ \displaystyle-\Delta\phi&\displaystyle=u^{2},&&\displaystyle x\in\mathbb{R}^{3% },\end{aligned}\right.

where

λ
>
0

{\lambda>0}

,

p
∈

(
3
,
6
)

{p\in(3,6)}

and the radial general perturbation term

g
⁢

(
x
)

∈

L

p

p
-
1

⁢

(

ℝ
3

)

{g(x)\in L^{\frac{p}{p-1}}(\mathbb{R}^{3})}

. By establishing a new abstract perturbation theorem based on the Bolle’s method, we prove the existence of infinitely many radial solutions of the above system. Moreover, we give the asymptotic behaviors of these solutions as

λ
→
0

{\lambda\to 0}

. Our results partially solve the open problem addressed in [Y. Jiang, Z. Wang and H.-S. Zhou, Multiple solutions for a nonhomogeneous Schrödinger–Maxwell system in

ℝ
3

\mathbb{R}^{3}

, Nonlinear Anal. 83 2013, 50–57] on the existence of infinitely many solutions of the Schrödinger–Poisson system for

p
∈

(
2
,
4
]

{p\in(2,4]}

and a general perturbation term g.
An adapted integration method for Volterra integral equation of the second kind with weakly singular kernel
Authors: Nemer Ahlem , Kaboul Hanane , Mokhtari Zouhir
Published: May 2021

In this paper, we consider general cases of linear Volterra integral equations under minimal assumptions on their weakly singular kernels and introduce a new product integration method in which we involve the linear interpolation to get a better approximate solution, figure out its effect and also we provide a convergence proof. Furthermore, we apply our method to a numerical example and conclude this paper by adding a conclusion
Modern reuse of ringstones: a case study from Eastern India
Authors: Bhattacharya Sutonuka
Published: May 2021

This study addresses issues related to the modern reuse of prehistoric ringstones in the Bargarh district, Odisha, India. Drawing on ancestral knowledge, ringstones are today used in a medicinal context by some agro-pastoral communities to heal cattle. Surveys of ten villages in a study area, which also includes two archaeological surface sites (Dekhulia and Kumbho), allowed investigations of the properties of ringstones and the ritualised context of their modern reuse.
The Association Between Personality Disorder Traits and Suicidality Following Sudden Bereavement: A National Cross-Sectional Survey
Authors: Zabihi Sedigheh , Jones Rebecca , Moran Paul , King Michael , Osborn David , Pitman Alexandra
Published: May 2021

Personality disorder is associated with increased risk of suicidal behavior. The authors aimed to investigate the association between number of personality disorder traits and suicidality risk following sudden bereavement. A secondary analysis of cross-sectional data on 3,167 young adults in the United Kingdom who had experienced sudden bereavement investigated the association between number of traits (measured using a standardized screening instrument) and postbereavement suicide attempt and suicidal ideation. Using multivariable logistic regression, the authors found a linear relationship between number of traits and suicide attempt (adjusted odds ratio [AOR] = 1.36, 95% CI [1.23, 1.49]) and suicidal ideation (AOR = 1.31, 95% CI [1.25, 1.38]) following bereavement. This represented an increase in odds by 36% and 31%, respectively, for each additional personality trait. The authors suggest that individuals with a greater number of traits suggestive of a personality disorder diagnosis are at increased risk of suicidality after a negative life event.
Prediction of Treatment Outcome of Adolescents With Borderline Personality Disorder: A 2-Year Follow-Up Study
Authors: Simonsen Erik , Vestergaard Martin , Storeb⊘ Ole Jakob , Bo Sune , J⊘rgensen Mie Sedoc
Published: May 2021

This study examined prediction of various clinical outcomes in adolescents with borderline personality disorder (BPD) features. Of the 112 adolescents who participated at baseline, 97 were seen at 2-year follow-up, of which 49 (50.5%) had clinically improved, defined as a decrease in BPD pathology of minimum 12 points on the Borderline Personality Features Scale for Children (BPFS-C). Eighty-one adolescents fulfilled the diagnostic criteria for BPD and scored above clinical cutoff on the BPFS-C at baseline, of which 26 (32%) had remitted at follow-up by self-report on the BPFS-C. Results showed that adolescents with comorbid oppositional defiant disorder at baseline were less likely to have clinically improved or remitted at follow-up. Participants with increased self-reported depression and less exposure to physical abuse at baseline had increased odds of remission. Our findings suggest that more internalizing and less externalizing symptoms increase the odds of positive treatment outcome in adolescents with BPD.
Self Psychology: The Ethics of Oneness
Authors: Kulka Raanan
Published: May 2021

A person's life and work, as recounted in a full-scale biography, is always a vibrant opportunity to touch the riddle's core, reflecting the sublime human yearning to see beyond the veil separating “I” from “other.” This is especially true in respect to Heinz Kohut, the founding father of self psychology. Strozier's (2001) monumental biography is used for a philosophical and historical scrutiny of Kohut's quest for the Grand Unity embodied in the monistic principle of holistic totality. This vision of laying the foundations of a supra-personal dimension in which the personal and the interpersonal amalgamate into an entangled universe is advocated as the spiritual core of Kohut's oeuvre. The vertical split between One Person Psychology and Two Person Psychology is, thus, healed by Kohut's revolutionary role in creating, explicitly and implicitly, a new kind of ethics in psychoanalysis: the ethics of Oneness.
A broad introduction to RNA-Seq
Authors: Richter Felix
Published: May 2021

RNA-Seq, named as an abbreviation of "RNA sequencing" and sometimes spelled RNA-seq, RNAseq, or RNASeq, uses next-generation sequencing (NGS) to reveal the presence and quantity of ribonucleic acid (RNA) in a biological sample at a given moment.[1][2] RNA-Seq is used to analyze the continuously changing cellular transcriptome (Figure 1). Specifically, RNA-Seq facilitates the ability to look at alternative gene spliced transcripts, post-transcriptional modifications, gene fusion, mutations/single nucleotide polymorphisms (SNPs) and changes in gene expression over time, or differences in gene expression in different groups or treatments.[3] In addition to messenger RNA (mRNA) transcripts, RNA-Seq can look at different populations of RNA to include total RNA, small RNA, such as microRNA (miRNA), transfer RNA (tRNA), and ribosomal profiling.[4] RNA-Seq can also be used to determine exon/intron boundaries and verify or amend previously annotated 5' and 3' gene boundaries. Recent advances in RNA-Seq include single cell sequencing, in situ sequencing of fixed tissue, and native RNA molecule sequencing with single-molecule real-time sequencing.[5] Prior to RNA-Seq, gene expression studies were done with hybridization-based microarrays. Issues with microarrays include cross-hybridization artifacts, poor quantification of lowly and highly expressed genes, and needing to know the sequence a priori.[6] Because of these technical issues, transcriptomics transitioned to sequencing-based methods. These progressed from Sanger sequencing of Expressed Sequence Tag libraries, to chemical tag-based methods (e.g., serial analysis of gene expression), and finally to the current technology, next-gen sequencing of complementary DNA ( cDNA), notably RNA-Seq.
Ultrasound-catalyzed TEMPO-mediated oxidation of native cellulose for the production of nanocellulose: Effect of process variables
Authors: Mishra Shree P. , Thirree Jennifer , Manent Anne-S. , Chabot Bruno , Daneault Claude
Published: May 2021

In this study application of ultrasound in oxidizing native cellulose for the production of nanocellulose has been explored for the first time. Bleached hardwood kraft pulp was oxidized with an ultrasound (US) catalyzed 2,2,6,6-tetramethylepiperidin-1-oxyl (TEMPO) system (US-TEMPO-system) at five different temperatures – 5, 15, 25, 35, and 45°C and two pH ranges, 8.5-9.0 and 10.0-10.5 – to obtain the optimum reaction conditions. The reaction pH and temperature have significant effect on the kinetics of the formation of carboxylate in the oxidized pulps and produce depolymerization at temperatures greater than 25°C. Formation of carboxylate on the cellulose chain is directly proportional to the NaBr concentration. The pulp oxidized by the US-TEMPO-system at 25°C had 10-15% more carboxyls and showed a ca. 10% increase in the nanocellulose yield when compared to the TEMPO-system without sono-catalysis.
Complete characterization of wheat straw (Triticum aestivum PBW-343 L. Emend. Fiori & Paul.) – A renewable source of fibers for pulp and paper making
Authors: Singh Shalini , Dutt Dharm , Tyagi C. H.
Published: May 2021

Triticum aestivum PBW-343 is grown in most of the regions of India, and it is one of the renewable sources most suitable for papermaking. Anatomical studies illustrate that vascular bundles near the periphery contain a strong sheath of sclerenchyma cells, which constitutes about 80% of the fibers. The total fibers in wheat straw are about 39.20%, and parenchyma and epidermal cells account for 32.10, and 23.56%, respectively, of the total cells. The dimensions of wheat straw fibers are: average fiber length 1.18 mm, fiber width 13.60 µm, lumen diameter 5.68 µm, and cell wall thickness 3.96 µm. The dimensions of non-fibrous cells are: parenchyma 445×124 µm, vessels 96×57 µm, and epidermal cells 390×38 µm, which lie between the corresponding values for rice straw, and bagasse. Flexibility coefficients and Runkel ratio of wheat straw fires are quite comparable to bamboo. The low lignin contents of wheat straw reflect that it requires mild cooking conditions; however, hemicelluloses are on higher side. Addition of AQ under optimum soda cooking conditions improves pulp yield by 0.75%, and lowers kappa number by 26.1%. Optimum strength properties are obtained at 45±1 oSR except tear index, which declines with increased refining. The fine contents are much higher, and relatively comparable to Eucalyptus tereticornis in terms of curl index and kinks per mm.
Adsorption of Cr(III) from aqueous solutions by polyacrylamide-grafted rubberwood fibre: Kinetics, equilibrium, and thermodynamic studies
Authors: Mahdavi Mahnaz , Ahmad Mansor B. , Haron Md Jelas , Ab. Rahman Mohamad Zaki
Published: May 2021

Cr(III) ions were adsorbed onto polyacrylamide-grafted rubberwood fibre, and effects of aqueous conditions were evaluated. The adsorbent was prepared via graft copolymerization of acrylamide (Am) onto rubberwood fibre (RWF), using ceric ammonium nitrate as an initiator. Fourier transform infrared spectroscopy was used to confirm the formation of PAm-g-RWF. Various variables affecting the adsorption capacity such as the pH of the solution, adsorption time, initial metal ion concentration, and temperature were investigated. The Cr(III) was up to 92% removed by PAm-g-RWF from an initial concentration of 10 mg/L at pH 5.0. Kinetic data fitted very well to a pseudo-second-order rate expression and less well to a pseudo-first-order equation. The equilibrium parameters for adsorption isotherms of the metal ions on the grafted fibre were obtained using Langmuir and Freundlich models, and the Langmuir model was found to be in better correlation with the experimental data with a maximum adsorption capacity of 18.24 mg/g. Thermodynamic parameters such as enthalpy change (ΔH°), free energy change (ΔG°), and entropy change (ΔS°) were calculated; the adsorption process was spontaneous and endothermic.
Soft Computing Under Uncertain Knowledge
Authors: García Gustavo Santos , Buitrago Rocio Santos
Published: May 2021

The early publications in the theory of fuzzy sets by Zadeh and Goguen show the intention to generalize the classical notion of a set and to accommodate the fuzziness that is contained in human language, namely human judgement, evaluation, and decisions. This article aims to show several approaches that allow effective treatment of uncertain, inaccurate, or unknown knowledge. On the one hand, a brief review of the theoretical background for these different paradigms is provided. On the other hand, the different extensions of soft sets are justified in the application to decision making. We pay special attention to applications in the medical sciences and provide a study case for biological signaling pathways.
Neuromeningeal cryptococcosis in HIV-infected patients in Lubumbashi, Democratic Republic of the Congo
Authors: Katabwa Joe Kabongo , Mukuku Olivier , Lwamba Guy Kanja , Wembonyama Stanislas Okitotsho
Published: May 2021

Introduction: Neuromeningeal cryptococcosis (NMC) is a severe and fatal opportunistic infection. Lethality is higher in the absence of treatment, especially in HIV co-infection. The objective of the present study was to determine the prevalence, epidemiological, clinical, biological, and therapeutic features as well as the outcome of NMC in HIV-infected patients. Methods: This is a retrospective study of 108 cases of NMC diagnosed in HIV-infected patients. Data were collected over 36 months (from January 2015 to December 2017) at the HIV/AIDS Center of Excellence in Lubumbashi (Democratic Republic of the Congo). Results: The overall prevalence of NMC is 2.5%. The mean age of the patients was 41.5±13.1 years, with 72.2% aged less than 50 years. The main clinical symptomatology was headache (100%) and fever (100%). The main cytochemical CSF abnormalities were hyperproteinorachia (91.9%), hypoglycorachia (94%) and hyper-lymphocytosis (98.2%). The mean CD4 count was 168.7±137.1/mm3. All patients were treated with fluconazole. The overall lethality was 43.5%. Conclusion: NMC is a serious opportunistic infection in HIV-infected patients, and the case fatality rate remains unacceptable. Management of NMC in HIV-positive patients requires early diagnosis, increased access to antiretrovirals and prompt initiation of appropriate treatment.
Structured financial producs trading and it's implementation perspectives in emerging economies
Authors:   Finance and Financial Institutions department, Azerbaijan State Economic University (UNEC), Namazov Vugar
Published: May 2021

The main objective of the research is to examine key aspects of the structured trade financing instruments and to analyze prerequisites for its existence. Hereby, the main focus is concentrated around developing economies. The research was carried out based on research methods such as comparative analysis, empirical approaches and logical generalization. Also, for the research purposes the current market situation, infrastructure, opinions and recommendations of international organizations were analyzed, and an optimal model and market conditions were generated. As a result of research an importance of the derivative financial instruments, organization of spot markets and warehouse receipt systems were investigated. The main factor limiting the study is a variable statistical need and mathematical modeling based on the economic specifications of each economy. As each market will need more country-oriented research and solution rather than general model that suits all. The practical significance of the research is to ensure synergies between financial and commodity markets and to develop a sustainable risk management tool, enhance access to capital by introducing an alternative financial instrument and market environment for local producers, including small and medium size entrepreneurs.
Problem of angular motion control of a non-cooperative on-orbit service object
Authors:   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Fokov A.A. , Savchuk O.P. ,   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine
Published: May 2021

The realization of existing projects of on-orbit servicing and the development of new ones is a steady trend in the development of space technology. In many cases, on-orbit service clients are objects that exhibit an undesired rotary motion, which renders their servicing difficult or impossible. The problem of on-orbit service object motion control determines the topicality of studies aimed not only at the refinement of methods and algorithms of controlling both the translational and the rotary motion of an object, but also at the development and refinement of methods of onboard determination of the object – service spacecraft relative motion parameters. This paper overviews the state of the art of the problem of object motion parameter determination in on-orbit servicing tasks and existing methods of object motion control and angular motion damping and specifies lines of further investigations into the angular motion control of non-cooperative service objects. Based on the analysis of publications on the subject, the applicability of onboard means for object motion parameter determination is characterized. The analysis of the applicability of methods of remote determination of the parameters of an unknown non-cooperative object from a service spacecraft shows that they are at the research stage. The input data for the verification of methods proposed in the literature were simulated or taken from ground experiments or previous missions. Contact and contactless methods of angular motion control of non-cooperative on-orbit service objects are considered. From the state of the art of investigations into the contactless motion control of on-orbit service objects it may be concluded that the most advanced contactless method of motion control of an on-orbit service object is a technology based on the use of an ion beam directed to the object from an electrojet engine onboard a service spacecraft. Lines of further investigations into non-cooperative object motion control are proposed.
Models of space object motion based on time series of TLE-elements
Authors:   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Sarychev O.P. , Perviy B.A. ,   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine
Published: May 2021

Timely detection of changes in the characteristics of space hardware objects during their long-term operation is one of the main tasks in the development and study of onboard systems that maintain the efficiency of their operation. This paper presents a statistical method for simulating the motion of space objects (spacecraft and used launch vehicle stages) in the class of autoregressive models. The method allows one to improve the quality of description and prediction of the motion of space objects based on simulating time series of their TLE-elements (two-line orbital element sets). The purpose of this work is to increase the accuracy of mathematical models of the observed motion of space objects in the problems of deorbit time determination, satellite collision prediction, and space debris cataloging. The paper presents a system for simulating the motion of space objects, which allows one to determine an optimal amount of learning samples in simulating time series of TLE elements, determine the order of autoregression and find an optimal model structure for each variable element, identify model parameters in conditions of unequally spaced observations, identify features of the time behavior of the root-mean-square errors of the constructed autoregressive models on the basis of dividing the initial time series of TLE-elements into successive learning intervals, and obtain predictive estimates of the values of variable elements. The proposed statistical method of space object motion simulation can be recommended to describe and predict the motion of spacecraft and used launch vehicle stages represented as time series of TLE-elements (which are publicly available and regularly updated). The application of the proposed statistical method will increase the accuracy of mathematical models of the observed motion of space objects in the problems of deorbit time determination, satellite collision prediction, and space debris cataloging.
Мodel of h-polarized wave propagation in a multilayer dielectric structure
Authors:   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Zabolotnyi P.I.
Published: May 2021

This paper addresses the determination of the dielectric constant of multilayer dielectric structures. One of the most-used methods for determining the dielectric constant of multilayer structures is reflection coefficient measurement by interferometry. In the general case, in interferometry measurements to one measured value of the reflection coefficient there may correspond an infinity of dielectric constants. This ambiguity may be resolved by first determining the effect of different parameters of the probing electromagnetic wave on the reflection coefficient. In particular, it is important to have a preliminary estimate of the effect of the incidence angle and the polarization on the range of variation of the reflection coefficient with the variation of one of the structure parameters. This allows one to estimate the boundaries of the range of variation of the reflection coefficient with the variation of the parameter under study. This paper considers the case where a plane H-polarized electromagnetic wave, i.e. a wave whose magnetic field is perpendicular to the incidence plane, is incident on a multilayer dielectric structure. The aim of this work is to develop a model of the propagation of an H-polarized electromagnetic wave through a multilayer dielectric structure at an arbitrary incidence angle and to determine the range of variation of the reflection coefficient with the variation of the dielectric constants of the layers. The paper presents a model of the propagation of an H-polarized electromagnetic wave in a two-layer dielectric structure. A metal base, which is an ideal conductor, underlies the structure. The electromagnetic wave is incident from the air at an arbitrary incidence angle. The model allows one to estimate the reflection coefficient of the structure as a function of its parameters and the incidence angle. The model also makes it possible to analytically estimate the range of variation of the reflection coefficient with the variation of the dielectric constant and the thickness of each layer of the structure. Using the model, the magnitude of the reflection coefficient was determined as a function of the incidence angle and the dielectric constant of the second layer.
Experimental analysis of the mechanical characteristics of launch vehicle parts manufactured by FDM additive technologies
Authors:   Yuzhnoye State Design Office, Derevianko I. , Avramov K. ,   A. Pidgorny Institute of Mechanical Engineering Problems of the National Academy of Sciences of Ukraine, Uspensky B. ,   A. Pidgorny Institute of Mechanical Engineering Problems of the National Academy of Sciences of Ukraine, Salenko A. ,   National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”
Published: May 2021

Additive manufacturing is very promising for aerospace engineering and aircraft construction. Using these technologies, light structures with preset strength properties can be made. For lack of tables of the mechanical properties of materials made by additive technologies, any calculation must be accompanied by the experimental determination of their mechanical properties. This paper presents an experimental approach to the determination of the mechanical characteristics of parts printed by FDM technologies. Parts manufactured from polymers by FDM technologies are shown to be orthotropic. Therefore, their elastic properties are described by nine constants: three Young’s moduli, three shear moduli, and three Poisson ratios. A cube is printed for the experimental determination of these constants. Six specimens are cut out from the cube. Three specimens are cut parallel to the cube edges, and the other three are cut at an angle of 45° to them. Each such specimen is manufactured in five pieces. This makes it possible to average the tensile stress–strain diagrams obtained for all the components of the stress tensor. The mechanical properties of the material are determined from these diagrams. The three Young’s moduli and the three Poisson ratios are determined from the three specimen types parallel to the cube edges. The three shear moduli are determined from the specimens cut at an angle of 45° to the cube edges. To determine these constants, tensile stress–strain diagrams are obtained experimentally. A technology is presented for manufacturing specimens on a Stratasys FORTUS 900 MC 3D printer. The mechanical properties of two polymer materials (ULTEM 9085 and PLA) are determined and compared. PLA has higher Young’s moduli and shear moduli and lower Poisson ratios than ULTEM 9085.
The golden jackal (Canis aureus) in the Tuzlivski Lymany National Nature Park
Authors:   Tuzlivski Lymany National Nature Park (Tatarbunary, Ukraine), Rusev Ivan
Published: May 2021

The article presents data on the appearance, spatial distribution, and ecological features of the golden jackal in the Tuzlivski Lymany National Nature Park. The estimated abundance of the jackal population is given along with its influence on local fauna of the national nature park. During the 20 years since the first jackals were recorded in the Ukrainian Black Sea coast, the jackal has become well-adapted to natural ecosystems of the Tuzlivski Lymany National Nature Park. Suitable protection and foraging conditions are provided in the park for this predator by steppe areas, sandbars of the Black Sea coast, and the artificial Lebedivskiy forest. For nursing the puppies, in addition to open natural habitats, especially reeds of wetlands, shrubs in the artificial forest, the jackal also uses burrows dug by itself. Currently, there are at least five jackal groups in the territory of the park. The number of broods and size of jackal groups fluctuates depending on seasonal climatic conditions and water level in the estuaries, which determine the availability of food and the character of hunting. The number of jackals in the park and surrounding areas was higher in 2020 than in the period when the water level in the estuaries was higher, and the number of jackals reached about 150 specimens. The population density of jackals in the park and surrounding areas is about 10 specimens per 1000 hectares. During the five years of observations in 2015 to 2020, the number of jackals increased slightly in the Tuzlivski Lymany National Nature Park due to the expansion of dry meadows to areas of former shoals. The area of sandbars has also increased providing access to the island systems where birds used to nest making these lands attractive for jackals as foraging sites. There is no sharp tendency to increase in the number of common jackals in the park. However, due to the likelihood of infection and spread of rabies by this predator species, some recreational areas should use rabies vaccine for oral immunisation of carnivores against rabies, which was done in September 2020 in the Lebedivskiy Forest tract of the park.
Muroid rodents of the natural landmark “Chervone” (Dnister Canyon): specifics of species composition and community structure
Authors:   Ivan Franko National University of Lviv (Lviv, Ukraine), Shtyk Olga , Mamchur Zvenyslava ,   Ivan Franko National University of Lviv (Lviv, Ukraine)
Published: May 2021

We conducted an analysis of populations of muroid rodents of the Dnister Canyon National Nature Park on the example of the natural landmark “Chervone.” For the investigation of the muroid rodents, we applied the trap-line method using factory-made live traps. According to methodology, the traps were located within a homogeneous habitat and four different sites were studies. Field data collected during 2017 and 2018 (summer and autumn cenuses) in four different habitats were analysed. The species composition of muroid rodents was investigated in four different biotopes (habitats) near the Dzurynskiy waterfall: hornbeam forest, pine forest, floodplain of the Dzuryn river, and pasture. The studied habitats were identified according to the National Habitat Catalogue of Ukraine. During the research, 75 specimens of muroid rodents were caught in 800 trap-nights. We recorded six species of muroid rodents: Sylvaemus tauricus L., Sylvaemus sylvaticus L., Apodemus agrarius Pallas, Micromys minutus L., Myodes glareolus Schreber, and Microtus arvalis Pallas. The most numerous species was Sylvaemus tauricus — 23 individuals (31 %). The quantity of other species was as follows: Apodemus agrarius (28 %), Sylvaemus sylvaticus (17 %), Myodes glareolus (16 %), Microtus arvalis (7 %), and Micromys minutus (1 %). The abundance of rodents was lower during the summer period compared to autumn, which can be related to the anthropogenic pressure on the investigated area. In addition, we investigated the sex and age structure of muroid rodent populations. We discovered that 45 individuals out of 75 were males and 35 were females. Additionally, 63 individuals were adults (Ad.) and 12 were juveniles (juv.). To summarise the received data, we calculated the number of individuals per 100 trap-nights. The abundance of individuals fluctuated from near 3 ind./100 t.-n. (Sylvaemus tauricus) to 0.125 ind./100 t.-n. (Micromys minutus). The relatively low species diversity of muroid rodents in the Dnister Canyon National Nature Park could be the result of small areas of insular habitats (separated territories with relatively similar landscape) and strong fragmentation of the researched area.
Nesting features of the red squirrel (Sciurus vulgaris) in conditions of Kamianets-Podilskyi
Authors:   Kamianets-Podilskyi National Ivan Ohienko University (Kamianets-Podilskyi, Ukraine), Matvieiev Mykola , Buchatska Olena ,   Kamianets-Podilskyi National Ivan Ohienko University (Kamianets-Podilskyi, Ukraine)
Published: May 2021

Research on the biotopic distribution, abundance, and specific nesting features of the European red squirrel (Sciurus vulgaris) was carried out from October 2016 until May 2017 in the entire area of Kamianets-Podilskiy (Khmelnitskiy Oblast, Ukraine). By its construction type and tree vegetation, the following biotopes were singled out in the town area: one-storey buildings, multi-storey buildings, mixed housing types, parks, industrial area, the Smotrych river’s canyon, and gardening area. In total, 272 nests of the European red squirrel were registered, including 89 nests in parks (32.7 % of the total number of nests), 79 in the industrial area (29.0 %), 49 in the mixed housing area (18.0 %), 19 in the area of multi-storey buildings (7.0 %), 13 in the area of one-storey buildings (4.8 %), 12 in the gardening area (4.4 %), and 11 in the canyon of the Smotrych river (4.0 %). In Kamianets-Podilskiy and its surroundings, 178 178 pairs of the European red squirrel were recorded, what makes up 65.4 % of the number of registered nests. The population density (pair/km2) of the red squirrel in Kamianets-Podilskiy is 6.4 pairs/km2. The highest density was observed in the forest-park area (43.3 pairs/km2), in the canyon of the Smotrych river (10.7 pairs/km2), and in the area multi-storey buildings (9.1 pairs/km2). Squirrel nests were observed on 21 tree species, including the linden Тіlіа sp., the asp Populus sp., the chestnut Aesculus hippocastanum, the sycamore tree Acer tataricum, the field maple Асеr саmреstrе, the elm tree Ulmus laevis, the sweet cherry Prunus sp., the maple Acer negundo, the fir tree Рісеа sp., the walnut tree Juglans regia, the horn beech Саrріnus bеculus, the willow Salix alba, the acacia Robinia pseudoacacia, the ash tree Frахіnus ехсеlsіоr, the birch tree Betula sp., the poplar Populus sp., the pyramidal poplar Populus pyramidalis, the cedar Thuja occidentalis, the Norway maple Acer platanoides, the honey locust Gleditsia triacanthos, and the oak Quеrсus rоbur. Most nests were located on the pyramidal poplar (24.1 %), linden (19.7 %), and Norway maple (13.7 %), while the least number of nests was found on the fir tree (0.8 %) and chestnut (0.8 %). The European red squirrel usually arranges its nests at the height of 3.5 m to 23 m, in average 9.3 m. The specific features of location of squirrel nests depend on the tree species (the highest nests being located on the ash tree, pyramidal poplar, and the lowest nests being on the fir tree and cedar). The squirrel mostly arranges its nests at whorls usually made up of 3–4 branches (51.9 %), near the trunk (32.7 %), on the branches (13.0 %) and between trunks (2.4 %).
Dampak Pemaksaan Pembelajaran Daring Dalam Pendidikan Islam Selama Pandemi COVID-19 Perspektif Neurosains
Authors: Rumata Faturrahman 'Arif , Suyadi Suyadi
Published: May 2021

Online learning in the midst of the COVID-19 pandemic was chosen to be a solution in replacing conventional learning which has had a serious impact on students. Limited internet access and the lack of creativity and innovation in the learning concept make students traumatized by education in undergoing the learning process. This paper wants to examine the impact of coercion in online learning during the COVID-19 pandemic as well as the impact on the brains of students. The research data comes from digital literature such as online news, journals, websites, and online documents. The collected data is then reduced and constructed into a new, whole and fresh concept. Data analysis was performed using content analysis that emphasizes intertextuality and meaning creativity. The results showed that the difficulties of online learning due to limited access and poor learning concepts created new problems for students, namely the weakening of student achievement. Students who are unable to access learning and understand learning material properly are not able to achieve competence. This condition will reduce the quality of education. Keywords: Online Learning, the impact of coercion, COVID-19, Islamic Education AbstrakPembelajaran daring di tengah pandemi COVID-19 dipilih menjadi solusi dalam menggantikan pembelajaran konvensional telah menimbulkan dampak serius bagi para peserta didik. Terbatasnya akses internet dan minimnya kreativitas dan inovasi dalam konsep pembelajaran membuat peserta didik menjadi trauma edukasi dalam menjalani proses pembelajaran. Tulisan ini ingin menguji seberapa besar dampak pemaksaan dalam pembelajaran daring selama masa pandemi COVID-19 serta dampak terhadap otak peserta didik. Data penelitian ini bersumber dari literatur digital seperti, berita online, jurnal, website, maupun dokumen-dokumen online. Data-data yang terkumpul, kemudian direduksi dan dikonstruksi menjadi konsep baru yang utuh dan fresh. Analisis data dilakukan dengan menggunakan analisis isi yang mengedepankan intertekstualitas dan meaning creativity. Hasil penelitian menujukkan bahwa kesulitan pembelajaran daring akibat keterbatasan akses dan konsep pembelajaran yang buruk menimbulkan masalah baru bagi para peserta didik yakni melemahnya prestasi belajar siswa. Siswa yang tidak mampu mengakses pembelajaran dan memahami materi pembelajaran dengan baik sama dengan tidak dapat mencapai kompetensi. Kondisi ini akan menurunkan mutu pendidikan. Kata Kunci: Pembelajaran Daring, Dampak Pemaksaan, COVID-19, Pendidikan Islam