bluuebunny/crossref_metadata_2025 huggingface dataset:
Levothyroxine use and the risk of colorectal cancer: a large population-based case–control study
Authors: Kuiper Josephina G , Fenneman Aline C , van der Spek Anne H , Rampanelli Elena , Nieuwdorp Max , van Herk-Sukel Myrthe P P , Lemmens Valery E P P , Kuipers Ernst J , Herings Ron M C , Fliers Eric
Published: December 2021

Objective

Whether an association between oral levothyroxine use, leading to supraphysiological exposure of the colon to thyroid hormones, and risk of colorectal cancer exists in humans is unclear. We therefore aimed to assess whether the use of levothyroxine is associated with a reduced risk of colorectal cancer in a linked cohort of pharmacy and cancer data.

Design

Population-based matched case–control study.

Methods

A total of 28,121 patients diagnosed with colorectal cancer between 1998 and 2014 were matched to 106,086 controls. Multivariable logistic regression was used to estimate the association between levothyroxine use and occurrence of colorectal cancer, adjusted for potential confounders. Results were stratified by gender, age, tumour subtype, and staging, as well as treatment duration and dosing.

Results

A total of 1066 colorectal cancer patients (4%) and 4024 (4%) controls had used levothyroxine at any point before index date (adjusted odds ratio 0.95 (0.88–1.01)). Long-term use of levothyroxine was seen in 323 (30%) colorectal cancer patients and 1111 (28%) controls (adjusted odds ratio 1.00 (0.88–1.13)). Stratification by tumour subsite showed a borderline significant risk reduction of rectal cancer, while this was not seen for proximal colon cancer or distal colon cancer. There was no relationship with treatment duration or with levothyroxine dose.

Conclusions

In this study, no reduced risk of colorectal cancer was seen in levothyroxine users. When stratifying by tumour subsite, a borderline significant risk reduction of rectal cancer was found and may warrant further research.
Estudio de pertinencia para el programa de negocios internacionales en modalidad en línea de la Universidad de Otavalo
Authors: Núñez Naranjo Santiago , De la Torre Altamirano Marina Soledad
Published: December 2021

El presente documento muestra los resultados del estudio de pertinencia para la carrera de negocios internacionales en modalidad en línea de la Universidad de Otavalo-Ecuador en 2020. El trabajo tuvo como objetivo determinar cuán pertinente es la propuesta en el contexto actual para la sociedad ecuatoriana. Para ello, se desarrolló una metodología basada en 4 componentes clave: necesidades y problemáticas de los negocios internacionales, tendencias de desarrollo en relación con la evolución de la problemática identificada, articulación de la propuesta con la problemática identificada, los objetivos, metas y políticas de los cuerpos normativos del país; y el estudio de mercado. Se demuestra que el escenario actual es el propicio para incursionar con programas innovadores en modalidad en línea, que existe una alta demanda de personas que requieren la profesionalización en negocios internacionales y a la vez una baja oferta en modalidad en línea de programas similares.
Estrategia VISPRECA para la igualdad de género en las aulas universitarias
Authors: Pleitez Herrera Miguel Ángel
Published: December 2021

La estrategia VISPRECA, es una propuesta de intervención socioeducativa orientada al nivel educativo superior, construida a partir de un proceso de investigación-acción con las cátedras de Técnicas de Investigación y de Evaluación de los Aprendizajes de la Facultad de Ciencias y Humanidades de la Universidad Modular Abierta en El Salvador. El propósito de la estrategia es brindar una herramienta metodológica y operativa a las personas que ejercen la docencia, facilitándoles la aplicación del enfoque de género en las cátedras universitarias desde una perspectiva restaurativa y colaborativa. Se orienta por los principios de visibilización, igualdad, sensibilización, problematización, reparación, cambio y acción; y, surge ante la necesidad de un abordaje más visible, humano y concreto del género en el aula que, además, sea transversal al proceso de enseñanza, constituyendo un ejercicio constante de diálogo crítico y problematizador del género durante todo el ciclo académico. A nivel metodológico, se incorporaron componentes de trabajo colaborativo y prácticas restaurativas, con relación a este último, se presenta una adecuación del círculo restaurativo, como una propuesta para plantear el enfoque de género, desde la cotidianidad de las relaciones entre los actores universitarios y desde los imaginarios sociales que entretejen las vidas de las personas participantes del proceso. Asimismo, se ha estructurado de tal forma que pueda ser una alternativa aplicable al flujo vital de la academia, articulándose a sus tres funciones: la docencia, la investigación y la proyección social. Lo que se presenta ha sido un proceso consensuado con estudiantes, y es en última instancia una alternativa sujeta a debates y mejoras acorde a cada contexto y experiencia de la persona que la aplique.
PRESENTACIÓN DEL TEMA. Alfabetización en salud
Authors: Pino Juste Margarita R.
Published: December 2021

A pesar de la importancia de la alfabetización en salud (AS) para la calidad de vida de todos los ciudadanos, todavía existe escasa investigación sobre el tema. En esta presentación hemos intentado plantear la situación actual que va desde las controversias sobre la utilización de este término hasta la necesidad de intervenciones en diferentes contextos dadas las repercusiones de un bajo nivel de AS para la salud individual, pero también colectiva. Ponemos de manifiesto, sobre todo, la escasa investigación sobre la eficacia de las intervenciones en el ámbito educativo. Y terminamos enumerando algunas estrategias y acciones educativas que sería necesario implementar.  En el monográfico se ha intentado paliar esta deficiencia introduciendo cinco artículos que permiten acercarnos al concepto y estrategias de intervención en varios contextos: escolar, comunitario, sanitario.
Left Atrial Appendage Circular RNAs Are New Predictors of Atrial Fibrillation Recurrence After Surgical Ablation in Valvular Atrial Fibrillation Patients
Authors: Zhu Xiyu , Wang Yali , Mo Ran , Chong Hoshun , Cao Cailong , Fan Fudong , Zhou Qing , Wang Dongjin
Published: December 2021

Background: Atrial fibrillation (AF) recurrence after ablation will increase mortality and morbidity during follow up. We attempted to evaluate the relationship between circular RNAs (circRNA) and AF recurrence to establish a predictive model for early intervention.
Methods: Patients who received surgical ablation retrospectively were analyzed. The expression of circRNAs were detected in the left atrial appendage. The independent risk factors of late recurrence were analyzed by multivariate analysis. The predictive model was visualized by Nomogram and tested by receiver operating characteristic curve and calibration plot. Kaplan-Meier plot was used to compare the rate of freedom from AF recurrence after surgery. The relationships between circRNAs and clinical characteristics were detected by Spearman’s correlation analysis.
Results: A total of 136 patients were enrolled from September 2018 to June 2019, 55 patients experienced late recurrence during one-year follow up. Increased age, longer AF duration and increased circ 81906-RYR2, circ 44782-LAMA2, circ 418-KCNN2 and circ 35880-ANO5 were detected in recurrent patients. Multivariate analysis revealed that increased age (odds ratio (OR)=1.072, P = 0.006), longer AF duration (OR=1.007, P = 0.036) and increased circ 81906-RYR2 (OR=2.210, P < 0.001) were independent risk factors for late recurrence. Area under the curve was 0.77, and the cut-off value was 70 points of the predictive model. Kaplan-Meier plots showed that patients over 70 points tended to experience AF recurrence.
Conclusion: Circ 81906-RYR2 could be a new predictor of late recurrence after surgical ablation. A predictive model consists of age, atrial fibrillation duration, and circ 81906-RYR2 was alternative for early intervention of AF recurrence.
60 Years of Databases
Authors:   Institute of Software Systems NAS of Ukraine, Reznichenko V.A.
Published: December 2021

The article provides an overview of research and development of databases since their appearance in the 60s of the last century to the present time. The following stages are distinguished: the emergence formation and rapid development, the era of relational databases, extended relational databases, post-relational databases and big data. At the stage of formation, the systems IDS, IMS, Total and Adabas are described. At the stage of rapid development, issues of ANSI/X3/SPARC database architecture, CODASYL proposals, concepts and languages of conceptual modeling are highlighted. At the stage of the era of relational databases, the results of E. Codd's scientific activities, the theory of dependencies and normal forms, query languages, experimental research and development, optimization and standardization, and transaction management are revealed. The extended relational databases phase is devoted to describing temporal, spatial, deductive, active, object, distributed and statistical databases, array databases, and database machines and data warehouses. At the next stage, the problems of post-relational databases are disclosed, namely, NOSQL-, NewSQL- and ontological databases. The sixth stage is devoted to the disclosure of the causes of occurrence, characteristic properties, classification, principles of work, methods and technologies of big data. Finally, the last section provides a brief overview of database research and development in the Soviet Union.
TAXONOMY AND SPECIES COMPOSITION OF EPIPHYTIC ALGAE IN STA. CRUZ RIVER, LAGUNA (PHILIPPINES)
Authors: Arguelles Eldrin De Los Reyes , Monsalud Rosario Gionson
Published: December 2021

Algal epiphytes attached on three dominant aquatic macrophytes (Pistia striatotes, Eichhornia crassipes and Ipomoea aquatic) were investigated as part of a preliminary study on the ecological assessment of Sta. Cruz River, which has been used primarily for agriculture and fishery. In total, 22 algal taxa were identified on the studied macrophytes: 8 Chlorophyta, 4 Cyanobacteria, 7 Bacillariophyta, and 3 Euglenophyta. The taxa in this paper represent 8 classes, 16 orders, 20 families, 22 genera and 22 species based on the latest algal taxonomical nomenclature. Among these taxa, the existence of a rare filamentous cyanobacteria, Planktothrix compressa (Utermöhl) Anagnostidis et Komárek is described for the first time in the Philippines. A species of diatom is also reported in this study for the first time based on recent algal taxonomic nomenclature and this is Ulnaria ulna (Nitzsch) Compère that is based on the former name of Synedra ulna (Nitzsch) Ehrenberg. These taxonomic records proved that aquatic macrophytes represents a unique habitat for novel and diverse types of algal flora, which demands further investigations in the country.
BENEFICIALL EFFECT OF THE EUROPEAN RASPBERRY (RUBUS IADEUS) EXTRACT ON THE ACTIVITY AND OXIDATIVE PROFILE OF BOVINE SPERMATOZOA
Authors: Kováč Ján , Árvay Július , Konečná Natália , Ďuračka Michal , Tvrdá Eva
Published: December 2021

Berries belong to the best dietary sources of bioactive compounds. These fruits contains bioactive compounds such as antioxidants (phenolic compounds and fruit colorants), vitamins (ascorbic acids) and minerals. This study aimed to estimate the effect of three concentrations (75 µg/mL, 150 µg/mL and 300 µg/mL) of the European raspberry (Rubus iadeus) on the selected quality parameters of bovine spermatozoa after 0h, 2h, and 24h of in vitro culture. Sperm motility was evaluated using the Computer-assisted sperm analysis (CASA) system. The mitochondrial activity was detected by the metabolic (MTT) assay. The determination of ROS (Reactive Oxygen Species) quantity was observed through the luminol method. The protein and lipid oxidation were evaluated using spectrophotometric assays. The experiment showed that the highest applied concentration of European raspberry extract at 2h (p<0.05) and all concentration after 24h (p<0.05; p<0.001) exhibited motility-promoting effects. We observed the highest increase of mitochondrial activity using 300 µg/mL by 2h (p<0.05) and using 150 µg/mL (p<0.05) and 300 µg/mL (p<0.01) after 24h. Exposure to this extract led to decreasing levels of ROS generation at 2h of incubation (p<0.05) with the highest dose as well as after 24h using 150 µg/mL (p<0.01) and 300 µg/mL (p<0.001) applied doses. The protein oxidation levels showed decreasing rates at 2h (p<0.05; 300 µg/mL) and at time of 24h (p<0.01; 150 µg/mL and p<0.001; 300 µg/mL). All selected raspberry concentration prevented oxidative degeneration of lipids during 2h (p<0.05) and after 24h (p<0.05; p<0.001). Our results indicate, that European raspberry extract has beneficial effect on the measured parameters of the bovine spermatozoa during in vitro incubation but depending on time and applied dose.
IDENTIFICATION OF VIRULENCE FACTORS AMONG ESBL-PRODUCING ESCHERICHIA COLI CLINICAL ISOLATES FROM GAZA STRIP, PALESTINE
Authors: Tayh Ghassan , NAGARJUNA Daram , BEN SALLEM Rym , VERMA Vivek , BEN YAHIA Houssem , GHARSA Haythem , YADAV Manisha , BEN SLAMA Karim
Published: December 2021

This study was done to assess the occurrence of virulence factors and correlation of phylogenetic grouping in ESBLs producing E. coli isolates from Palestine.
Twenty-seven ESBLs producing E. coli isolates were collected between April and June 2013 from three hospitals in Gaza. Detection of genes encoding virulence factors, pathogenicity associated island marker (PAI) and phylogenetic groups were studied by PCR. The correlation of E. coli phylogenetic grouping with the virulence factors in the isolates was studied. The clonal relationships between the isolates were tested by pulsed-field gel electrophoresis (PFGE).
Overall, 44.4% of the 27 E. coli isolates belonged to phylogroup B2, 44.4% to D and 11.2% to A. Among the isolates, fimH, traT and fimA were the most frequent virulence genes and were found over 85% of the isolates. PAIs was found in 8 isolates while the tcpC gene was detected in one isolate. The overall prevalence of PAI was higher in group B2 as compared to groups A and D (p<0.043). A clonal diversity was confirmed among our isolates (27 unrelated PFGE profiles). We report for the first time the prevalence of tcpC as a new virulence marker and PAI in clinical ESBLs-producing E. coli in Palestine.
This study indicates that most of the ESBL- positive isolates showed virulence genes and most strains belonged to phylogenetic groups B2 and D. The study suggested that high number of virulence genes in studied strains may be important factors in the infections development.
BIOETHANOL PRODUCTION FROM AGRICULTURAL WASTES BY ZYMOMONAS MOBILIS AND USED IN VINEGAR PRODUCTION
Authors: Nassir Tabark Hassan , Al-Sahlany Shayma
Published: December 2021

This review paper summarizes the best method for the utilization of agricultural wastes as raw material for the production of bioethanol. Agricultural wastes are rich in sugar and complex carbohydrates that makes it suitable source to carry out the fermentation process. Bioethanol is widely used in industries such as, chemical, pharmaceutical and food for various purposes especially as sterilizer. Carbohydrates are considered as the renewable sources and the primary material for the production of bioethanol.  Microorganisms such as some species of yeasts and bacteria are capable to ferment carbohydrates and convert it into ethyl alcohol. However, the ability of these micro-organisms differs with respect to the production of ethanol and this research we study the possibility of producing bioethanol from the bacterium Zymomonas mobilis.  One of the major industrial aspects of ethanol is the production of vinegar and there are several methods that could be utilized for its production from ethanol. Studies have reported that Zymomonas mobilis has 5-10 times more capability to produce bioethanol as compared with Saccharomyces cerevisiae. Therefore, this study has been done to highlight the possibilities of production of bioethanol from Zymomonas mobilis
ENHANCING THE ANTIBACTERIAL EFFECT OF BACTERIOCIN FROM LACTOCOCCUS LACTIS SUBSP. LACTIS USING CHITOSAN NANOPARTICLES
Authors: Guirguis Emad
Published: December 2021

Chitosan, a cationic polymer derived from the hot alkali deacetylation of chitin, has numerous biological applications with non-toxicity, biocompatibility and biodegradability. Chitosan nanoparticles were prepared and encapsulated with bacteriocin extracted from Lactococcus lactis subsp lactis to produce chitosan nanoparticles conjugate bacteriocin using ionic gelation method. This formulation was examined for its antibacterial activity representing food bio-preservative against Salmonella typhimurium, Escherichiae coli, Bacillus cereus and Staphylococcus aureus, compared with chitosan nanoparticles, crud chitosan and free bacteriocin.  Agar diffusion method was applied to evaluate the in-vitro drug release, effect of pH and temperature on its stability. The results revealed that the In-vitro release within 24 hours of chitosan nanoparticles conjugate bacteriocin was controlled by about (79%) with cumulative and sustained effect when compared with free bacteriocin (94%). Chitosan nanoparticles conjugate bacteriocin exhibit the highest antibacterial activity (with significant difference p < 0.05) followed by free bacteriocin and chitosan nanoparticles, while crud chitosan was the lowest representing thermal stability (≤ 70ºC) when subjected to low pH. Gram-positive bacteria were more susceptible than Gram-negative bacteria to all of the components. Chitosan nanoparticles contribute successful safe food preservative enhancement when incorporated with bacteriocin against the common food-borne pathogenic bacteria.
SIMULTANEOUS DETERMINATION OF SYNTHETIC DYES IN GUMMY CANDY USING NOVEL MESOPOROUS MAGNETIC GRAPHENE OXIDE@ZEIN AEROGEL FOLLOWED BY A HIGH PERFORMANCE LIQUID CHROMATOGRAPHY-DIODE ARRAY DETECTOR
Authors: Hamidi Samin , Nemati Mahboob , Lotfipour Farzaneh
Published: December 2021

The present work aimed to determine colorants used as food additives to confirm the gummy candy products authentication using a newly designed adsorbent in magnetic dispersive solid phase extraction. Nowadays, many kinds of synthetic dyes are widely added to food products and should be strictly monitored and regulated like other food additives. A mesoporous aerogel magnetic graphene oxide@zein adsorbent was prepared in a template-free and facile self-assembling manner for magnetic dispersive solid phase extraction extraction of 8 frequently used synthetic dyes in gummy candy samples. The adsorbent was designed and successfully characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, vibrating-sample magnetometry, and Brunauer–Emmett–Teller analysis. The isotherm parameters were calculated, and the amount of colorant was determined using high performance chromatography. The proposed method was validated according to the FDA guidelines over the concentration range of 0.05-50 µg/mL. The maximum adsorption capacities of the adsorbent for Tartrazine, Quinoline Yellow, Ponceau 4R, Sunset Yellow, Allura Red, Carmoisine, Indigo Carmine, and Brilliant Blue FCF were 43.3, 43.2, 26.9, 37.8, 38.3, 74.5, 28.3, and 19.9 mg g-1, respectively. Limits of detection (LODs) were from 5 to 20 ng/mL. Inter- and intra-day precisions and accuracies were within 10%. The developed method was proved specific to determine synthetic colorants in gummy candy samples and can be easily used in food quality control laboratories.
FUNGAL AND BACTERIAL RHIZOSPHERE MICROBIOME ASSOCIATED WITH SELECTED MELON AND SNAKE MELON GENOTYPES
Authors: AYDI BEN ABDALLAH Rania , Chikh-Rouhou Hela , Jabnoun-Khiareddine Hayfa , Sta-Baba Rafika , Daami-Remadi Mejda
Published: December 2021

The composition of rhizospheric microbial community may be shaped by plant genotype. Forty five melon (Cucumis melo L.) and seven snake melon (Cucumis melo var. flexuosus) genotypes were tested for their growth and yield parameters compared to a commercial melon cultivar “Star plus”. To estimate the microbial community in the rhizospheric soil of these genotypes, soil dilution plating technique on specific agar medium was used and compared to control. The majority of melon genotypes showed significantly comparable height, fruit weight and fruit yield per plant as “Star plus”. The fruit yield per plant varied significantly depending on tested genotypes. The total bacterial population in the rhizosphere of ten melon and two snake melon genotypes was significantly 59 to 68% higher than control soil. For most tested genotypes, a significant increase in the culturable rhizospheric actinomycetes, about 28.5 to 92.6%, was recorded comparatively to control soil. Fungal population counts in the rhizosphere of tested genotypes were significantly comparable to control. The genotypic difference in melon and snake melon reflects the quantum and diversity of their microbiomes that melon breeders could benefit when seeking at the holobiont concept to include associated microbiomes in breeding programs.
ASSESSMENT OF THE EFFECT OF PLANT GROWTH REGULATORS ON IN VITRO MICROPROPAGATION AND METABOLIC PROFILES OF MELISSA OFFICINALIS L. (LEMON BALM)
Authors: Petrova Maria , Nikolova Milena , Dimitrova Margarita , Dimitrova Lyudmila
Published: December 2021

In this study the effectiveness of plant growth regulators on micropropagation, total phenol content and metabolic profiles of Melissa officinalis L., important medicinal herb was assessed. The stem segments derived from one-month old in vitro germinated seedlings were used for initial explants. Of the eight different nutrient media tested the most favorable for micropropagation were found to be MP2 (MS medium enriched with 1mg/L BAP and 0.1 mg/L IBA) and MP3 (MS supplemented with 1.5 mg/L BAP and 0.5 mg/L NAA), which yielded 3.25- 4.0 shoots per explant within 4 weeks of culture. In vitro rooting (100%) was achieved on half strength MS medium contained 2% sucrose. Rooted plantlets were adapted successfully (98%) in a mixture of soil, peat, perlite, and sand in ratio 2:1:1:1 (v/v/v/v). Twenty metabolites were identified by GC/MS analysis of shoots grown on the MS media including different types of growth regulators. Analysis revealed the presence of phenolic, organic and fatty acids, sterols, triterpenes, fatty alcohols, saccharides and polyols. The studied samples have the same metabolic profile with quantitative differences in the individual metabolites. The maximum content of total phenols (13.92 mg/g extract) was obtained in shoots grown on MP2 medium and the lowest was recorded in the microplants cultured on MP1 control medium (8.45 mg/g extract). The obtained results indicated that it is possible to achieve the accumulation of desired metabolites by selection of plant growth regulators added in nutrient media.
KINETIC MODEL OF COMMERCIAL GLUCOSE-AFFECTED GROWTH AND MICROBIAL OIL PRODUCTION OF OLEAGINOUS YEAST Pseudozyma parantarctica CHC28
Authors: Areesirisuk Atsadawut , Teeka Jantima , Rakkitkanphun Chutima , Bunmadee Sunanta , Samranrit Thidarat , Khunthong Sasitorn , Kaewpa Dolnapa , Wanlapa Apinan
Published: December 2021

This research proposed to study the effect of commercial glucose concentration in a nitrogen-limiting medium on the growth of Pseudozyma parantarctica CHC28 and to estimate the kinetic parameters of fermentation. The biomass, microbial oil, biomass production rate (Qx), and oil production rate (Qp) increased dramatically and reached 22.10±1.95 g/L, 10.99±1.31 g/L, 0.184±0.016 g/L h, and 0.092±0.011 g/L h, respectively, when glucose concentration was increased to 100 g/L (C/N ratio = 333). In contrast, these results showed a decrease when glucose and C/N ratio were higher than 100 g/L and 333, respectively. Concurrently, the oil content showed a continuous rise as the glucose and C/N ratio increased. Furthermore, the maximum specific growth rate (μmax) declined sharply when P. parantarctica was cultivated under high glucose concentration. It was therefore suggested that the glucose concentration could affect the growth of oleaginous yeast because of osmotic pressure and C/N ratio. For the bioreactor scale, biomass, microbial oil, and oil content were enhanced to 29.92 g/L, 15.13 g/L, and 50.57 %w/w, respectively, at 120 hrs of cultivation. The mathematical models could describe the effect of glucose concentration on both yeast growth and microbial oil production. Thus, the kinetic model satisfactorily fitted the experimental data relating to oleaginous growth, microbial oil production, and substrate consumption.
MYCORRHIZA AND LICHENS AS TWO MODELS OF FUNGAL SYMBIOSIS
Authors: Elkhateeb Waill , Somasekhar Tiruveedhula , Thomas Paul , Wen Ting-chi , Daba Ghoson
Published: December 2021

Fungi have evolved many symbioses including different eukaryotes and prokaryotes. Mutualism is one of the symbioses and here both symbionts benefit from the interaction. The most common mutualistic relationships involving fungi are mycorrhiza and lichens. A mycorrhiza is a symbiotic relationship between a roots of a plant and a fungus while lichen associates between a fungus and an algae. Many studies have performed to investigate these symbiotic relationships in depth, however, still have some debates on them, though many taxonomists rely on genetic analyses besides with traditional morphological data. In our study, it highlights the nature, importance, nutritional and pharmaceutical uses, and applications of these mysterious dual between fungi and plant and/or algae.
Tekstura drzewostanów naturalnych w polskich parkach narodowych na tle teorii dynamiki lasu
Authors:   University of Agriculture in Krakow, Bartkowicz Leszek
Published: December 2021

The aim of the study was to compare a patch-mosaic pattern in the old-growth forest stands developed in various climate and soil conditions occurring in different regions of Poland. Based on the assumption, that the patch-mosaic pattern in the forest reflect the dynamic processes taking place in it, and that each type of forest ecosystem is characterized by a specific regime of natural disturbances, the following hypotheses were formulated: (i) the patches with a complex structure in stands composed of latesuccessional, shade-tolerant tree species are more common than those composed of early-successional, light-demanding ones, (ii) the patch-mosaic pattern is more heterogeneous in optimal forest site conditions than in extreme ones, (iii) in similar site conditions differentiation of the stand structure in distinguished patches is determined by the successional status of the tree species forming a given patch, (iv) the successional trends leading to changes of species composition foster diversification of the patch structure, (v) differentiation of the stand structure is negatively related to their local basal area, especially in patches with a high level of its accumulation. Among the best-preserved old-growth forest remaining under strict protection in the Polish national parks, nineteen research plots of around 10 ha each were selected. In each plot, a grid (50 × 50 m) of circular sample subplots (with radius 12,62 m) was established. In the sample subplots, species and diameter at breast height of living trees (dbh ≥ 7 cm) were determined. Subsequently, for each sample subplot, several numerical indices were calculated: local basal area (G), dbh structure differentiation index (STR), climax index (CL) and successional index (MS). Statistical tests of Kruskal- Wallis, Levene and Generalized Additive Models (GAM) were used to verify the hypotheses. All examined forests were characterized by a large diversity of stand structure. A particularly high frequency of highly differentiated patches (STR > 0,6) was recorded in the alder swamp forest. The patch mosaic in the examined plots was different – apart from the stands with a strongly pronounced mosaic character (especially subalpine spruce forests), there were also stands with high spatial homogeneity (mainly fir forests). The stand structure in the distinguished patches was generally poorly related to the other studied features. Consequently, all hypotheses were rejected. These results indicate a very complex, mixed pattern of forest natural dynamics regardless of site conditions. In beech forests and lowland multi-species deciduous forests, small-scale disturbances of the gap dynamics type dominate, which are overlapped with less frequent medium-scale disturbances. In more difficult site conditions, large-scale catastrophic disturbances, which occasionally appear in communities formed under the influence of gap dynamics (mainly spruce forests) or cohort dynamics (mainly pine forests), gain importance.
Análise empírica da volatilidade do etanol: aplicação de modelos ARCH nos preços à vista e futuros no período 2011-2015
Authors: Santos Ramon Rodrigues dos
Published: December 2021

Esta pesquisa teve a finalidade de analisar a dinâmica e a transmissão da volatilidade dos preços à vista e futuros do etanol pelos modelos ARCH, GARCH, EGARCH e TARCH.  A amostra utilizada nesta pesquisa é composta pelas cotações diárias do etanol hidratado spot negociado na base de Paulínia (SP), disponibilizadas pelo CEPEA/ESALQ e das cotações futuro na CBOT (Chicago Board of Trade) Denatured Fuel Ethanol Futures), no período de 03/10/2011 a 27/11/2015, em um total de 2.032 observações. Dentre os modelos analisados, destaca-se que os modelos EGARCH (2,2) para o spot e EGARCH (1,2) para o futuro são os que possuem o melhor ajustamento da série, considerado os Critérios de Informação de Akaike (AIC) e de Schwarz (SC), demonstrando um efeito assimetria principalmente na série de retornos futuros do etanol, e mostrando que os impactos resultantes dos choques positivos e negativos foram diferenciados na volatilidade, dentro do período analisado.
Mortality Profile of the Non-Hispanic American Indian or Alaska Native Population, 2019
Authors: Anthony Sawyer , Lee Anne Flagg
Published: December 2021

NVSR 70, no. 12
Proton Migration on the Boron Sheets Surface
Authors:   Volgograd State University, Boroznina Evgeniya , Smirnov Konstantin ,   Volgograd State University, Akatiev Vladimir ,   Volgograd State University, Kudinova Marina ,   Volgograd State University
Published: December 2021

Borophene is a two-dimensional allotrope of boron and it is also known as boron sheet. First it has been predicted theoretically in the mid-1990s, experimentally borophene was confirmed in 2015 when the structure was successfully synthesized in 2015. One of the key features of borophene is its strong anisotropy – the dependence of mechanical and electrical properties on direction. This phenomenon is not typical for 2D materials and has never been observed in 2D metals before. Borophene has the highest tensile strength of all known two-dimensional materials. In early works, it was found that the adsorption of a hydrogen atom on the surface of borophene is possible and the analyses of electronic density showed that atom H became a proton. Therefore, in this work, the authors have studied the proton migration over the surface of boron sheets of two types and have found the most energetically favorable path of proton motion. The electron-energy characteristics of the process of migration of a single proton along the surface of boron layers of two types are determined and it is established that in all the considered cases the proton is able to move along the surface almost barrier-free. The type of conductivity of pure boron layers and layers modified by a single proton is determined. In the A-type boron layer, the proton increases the band gap by 0.04 eV, and in the B-type layer, the band gap changes by 0.05 eV. It is proved that two-dimensional boron nanostructures can be considered as a new class of boron topological structure with proton conductivity.
Investigation of the Durability of Nanomarkings Applied to Steel Products Using a Scanning Probe Microscope Under the Influence of Operational Factors
Authors:   Volgograd State University, Kislova Tatyana
Published: December 2021

The criminogenic situation in Russia today is characterized by a high level of crime. This is evidenced by the official data of the Federal State Statistics Service and the Ministry of Internal Affairs of Russia. In January 2020 alone, 496 crimes related to the use of weapons were committed. One of the problems that law enforcement agencies face when investigating crimes is establishing the authenticity or verification of items found during operational investigative actions. To increase the probability of verification of items, a number of preventive measures are necessary. As such a preventive measure, the protective marking of items of increased interest from criminal structures can act. The application of marking marks can be used to protect property rights, protect against counterfeit products, as well as by various law enforcement agencies for marking weapons. The protective properties of the marking are increased if it is latent, that is, it is not perceived visually, including with the help of available magnifying devices. In this work, the impact of operational factors on the dynamics of changes in the parameters of nanomarkings applied to steel parts is studied using a new innovative technology-scanning probe microscopy, which provides one hundred percent verification of subjects and objects.
Determination of Blood Vessel Parameters by Pulse Wave
Authors:   Saratov National Research State University, Suchkov Sergey , Suchkov Dmitry ,   Saratov National Research State University, Suchkova Svetlana ,   LLC “Conversion-SSU”
Published: December 2021

A pulse wave is a complex joint motion of blood and vessel walls described by a nonlinear system of differential equations of hydrodynamics and elasticity theory with a mobile boundary. Even an approximate solution to such a problem is currently not possible without significant simplifications, reducing the problem to almost uninteresting cases. Therefore, to mathematically describe the practically important changes in the pulse wave between the norm and pathology and to identify the main physical parameters that characterize the pathology, it is necessary to build a phenomenological model, the parameters of which are determined from comparison with the experiment.The results obtained indicate that the pulse wave transformation in the cuff area is significantly nonlinear in pressure. Attention is also drawn to the effect of a decrease in the elastic modulus with an increase in the diameter of the vessel.
Geodemographic Dynamics of Crimean Population: Main Trends and Factors of Post-Soviet Period
Authors:   Federal Research Centre the Southern Scientific Centre of the Russian Academy of Sciences, Suschiy Sergey
Published: December 2021

The article examines the geodemographic dynamics of the Crimea in the post-Soviet period: changes in the population of the peninsula, its centers and territories; changeable ratio of natural and migration components, and shifts in the settlement system. In the dynamics of the processes under analysis, four stages are distinguished: three of them relate to the Ukrainian period of the Crimea’s development, and the last one it is the Russian stage which begins in 2014. Until the mid-1990s (the first stage), the population of the peninsula continues to grow, despite the natural decline and increased outflow to Russia. The main reason for this is the large-scale re-emigration of Crimean Tatars to the peninsula, most of whom settle in the interior of the Crimea. The next stage (late 1990s – the middle of the 2000s) is associated with a significant depopulation of the region, primarily due to a high natural population decline. The third stage (the second half of the 2000s – the beginning of the 2010s), at which the depopulation is replaced by a minimal increase in the population of the peninsula, is associated with an improvement of the indicators of its natural reproduction and a certain increase in the migration influx. The features of the Russian development stage are set by two multi-component processes. Migration activity is determined by the consequences of the transition of the Crimea to Russia. Meanwhile in the natural reproduction, a central role is played by a small generation of the 1990s entering into the reproductive age, with such consequences as a rapid decline in the birth rate and an increase in natural loss. The result of these processes is a certain stabilization of the population of the Crimea. The situation in which the natural decline is offset by the migration influx is likely to continue in the nearest future and in the medium term period (until 2030–2035). The main trend in the spatial distribution of the demographic potential of the Crimea in the last 15–20 years is a gradual increase in the proportion of the population settled on the coast and in the coastal zone 15–20 km wide.
Industrial Development in the South of Russia in Conditions of COVID-19 Crisis
Authors:   Southern Federal University, Chernova Olga
Published: December 2021

The coronavirus pandemic caused significant damage to the economy of the regions. The comprehension of the impact of pandemic on industrial development of the territory is the goal of many scientific studies. The purpose of this article is to identify trends in the development of certain industrial sectors in the South of Russia and to suggest managerial measures arising from the experience of the COVID-19 pandemic. The study was founded on monitoring data from the Federal Service for State Statistics of Russia. The object of the research was the old industrial regions in the South of Russia. During the study, it was determined that at the beginning of the pandemic, the economy of the regions under analysis was characterized by a low potential for innovative development and a low level of return on assets. With a high demand for digital technologies, they have become most widespread in the automation of internal business processes of enterprises. The impact of the COVID-19 crisis on individual sectors of industry turned out to be multidirectional. The most affected industrial sector was oil production. The economic growth was demonstrated by enterprises of agricultural engineering, metallurgy and a number of others. It is shown that the recovery of industrial production is complicated by a low level of development of its material and technical basis; high import dependence of production on components, raw materials, spare parts; high competition from foreign market players; shortage of human capital. It is concluded that industrial ecosystem structures are the drivers of economic growth in the conditions of the pandemic. Management recommendations which are aimed at the development of industrial ecosystems are provided. They are focused on the environmental component of industrial production, development of cooperative business interactions to maintain the sustainability of the supply chain, digitalization of business processes with the simultaneous development of smart competencies of personnel, import substitution production and focus on the domestic market.
Efficiency Assessment of Measures for Sustainable Development of the Region Under the Uncertainty of Coronavirus Crisis
Authors:   Volgograd State University, Klenova Tatiana , Batmanova Victoria ,   Volgograd State University, Vatyukova Oksana ,   Volgograd State University
Published: December 2021

The article presents efficiency assessment of sustainable development measures in the region in the face of uncertainty caused by the COVID-19 pandemic. The economic crisis caused by the pandemic is one of the most serious in recent decades. Its global nature is due to the scale of economic and social losses, aggravation of production problems for many industries and enterprises. Like other regions of the Russian Federation, Volgograd region has repeatedly faced crises since the early 2000s, and each of them has become a new challenge for the regional administration system in terms of its ability to develop and take timely measures to overcome negative consequences. In the article, a number of indicators were analyzed for three consequent periods. The first one is 2019 in comparison with 2018. The second period is 2020 in comparison with 2019. The third one is the beginning of 2021 and each of them is characterized by the ratio of various factors that influence the behavior of business entities, population of the region, development and use of managerial decisions aimed at sustainable social and economic development of Volgograd region. The recovery from the pandemic crisis became the most important task for regional authorities, which is reflected in the set of measures aimed at support of the economy and social sphere of the region, incomes of the population and businesses. It became necessary for public authorities to improve new rules of work and decision-making mechanisms in order to respond to the current situation in a timely manner. The authors believe that the main factors of success of the measures implemented by regional authorities were their quality, timeliness and degree of compliance with the set goals. Analysis and generalization of management experience during the corona virus crisis allowed us suggesting long-term measures aimed at the sustainable development of Volgograd region.
Assessment of Stability Level of Functioning and Development of Business Entities Within the System of Industrial Parks
Authors:   State Scientific Center of the Russian Federation, I.P. Bardin Central Research Institute of Ferrous Metallurg, Brusnikin Konstantin , Piskun Elena ,   Sevastopol State University
Published: December 2021

The need to study the development of business entities in the context of individual categories of industrial parks is connected with different concepts of their development and territorial expansion. The suggested methodological approach to assessment of sustainability level of the business firms functioning in the system of industrial parks includes the following main stages: grouping of industrial parks and the selection of representatives of the groups; rating assessment of stability level of firms functioning in the system of industrial parks; grouping of businesses by the level of sustainability. The technique was tested on data from 150 industrial parks. The results of the implementation of the suggested approach show that more vulnerable positions are typical of businesses operating as part of industrial parks as “greenfield” companies. At the same time, the highest proportion of businesses with a low stability level is typical of developing parks, which indicates the need to expand the range of incentives for these businesses. The most stable cluster of entrepreneurs is business entities of developing parks such as “brownfield” companies. Entrepreneurs operating within developed parks as “brownfield” firms are characterized by a satisfactory level of sustainability. The proportion of entrepreneurial structures with a low stability level remains quite high, which indicates the need to adapt the development strategy of business entities in the system of such structures. The results obtained made it possible to identify the most vulnerable groups to risks, business entities and can be used to form a strategy for their sustainable development in the system of industrial parks.
Development of Regional Commercial Banks in Digital Economy: Risks and Opportunities
Authors:   Volgograd State University, Simaeva Natalia , Ryabova Inna ,   Volgograd Institute of Management, Branch of the Russian Presidential Academy of National Economy and Public Administration
Published: December 2021

The article is devoted to the analysis of the activity of regional commercial banks. The purpose of this article is to identify risks and prospects for the development of regional commercial banks in the digital economy. The author explores the concept of a regional bank, analyzes the peculiarities of the activities of regional banks in modern conditions of increasing banking competition. The article analyzes the state and trends of the development of the banking regional sector from the point of view of efficiency increase of their activities. It is shown that the number of regional banks is constantly declining, and a number of constituent entities of the Russian Federation do not have any longer in the structure of their regional banking system banking credit organizations chartered in their territory as a legal entity. The authors concluded that the development of regional banks can be efficient only through the qualitative growth of each individual regional bank, since in quantitative terms this sector of the Russian banking systems will only decrease. As an example the activity of Rostov bank Tsent-Invest and the regional bank of the Republic of Tatarstan Ak Bars Bank are shown, which occupied certain niches in the Russian banking system and fully compete with foreign banks. To identify and assess the current risks of the activity of regional banks specific characteristics of the digital transformation of the banking industry are determined. As the main risks of development, the authors identified the following ones: risk of increased banking competition, on the one hand, and the risk of monopolization of the banking market, on the other; risk of underfunding of financial technologies; information risks and cyber risks; risks of insufficient financial literacy of consumers of banking products and services; risks of customer base reduction. As opportunities for the development of regional banks the use of remote banking services, allowing to attract new customers, expansion of participation in the state programs, emergence of opportunities for the introduction and development of new business models, in particular ESG-banking are identified. The Bank of Russia can provide certain support for the development of regional banks in the context of digital transformation and increasing banking competition by creating and developing nationwide banking infrastructure platforms.