bluuebunny/crossref_metadata_2025 huggingface dataset:
The Flash Flood Guidance System Implementation Worldwide: A Successful Multidecadal Research-to-Operations Effort
Authors: Georgakakos Konstantine P. , Modrick Theresa M. , Shamir Eylon , Campbell Rochelle , Cheng Zhengyang , Jubach Robert , Sperfslage Jason A. , Spencer Cristopher R. , Banks Randall
Published: November 2021

At the beginning of the twenty-first century a research-to-operations program was initiated to design and develop operational systems to support local forecasters in their challenging task to provide advance warning for flash floods worldwide. Twenty-some years later, the Flash Flood Guidance System with global coverage provides real-time assessment and guidance products to more than 60 countries, serving nearly 3 billion people. The implementation domains cover a wide range of hydroclimatological, geomorphological, and land-use regimes worldwide. This flexible and evolving system combines meteorology and hydrology data and concepts as well as supports product utility for flash flood disaster mitigation on very large scales with high spatial and temporal resolution. Through quality control procedures, it integrates remotely sensed data of land surface precipitation and of land surface properties from geostationary and polar-orbiting satellite platforms, reflectivity data from a variety of weather radar systems, and asynchronous precipitation data from ground-based automated precipitation gauges in order to produce assessments and short-term forecasts that support forecasters and disaster managers in real time. For each region, it also integrates mesoscale meteorological model forecasts with land surface model response to produce longer-term guidance products. It contains components and interfaces that allow real-time forecaster adjustments to products based on local last-minute field information and relevant forecaster experience. Assessments of utility for flash flood warning operations by national forecasting agencies worldwide are positive. The article exemplifies the process of realization and evolution of the Flash Flood Guidance System (FFGS) from research in interdisciplinary fields to operations in diverse environments, and discusses lessons learned.
Oral histiocytic sarcoma in a cat with mandibular invasion and regional lymph node metastasis
Authors: Ruppert Stephani L , Ferguson Sylvia H , Struthers Jason D , Jones Teela L
Published: November 2021

Case summary

An 11-year-old female spayed domestic medium-hair cat presented for dental prophylaxis, at which time no oral mass was appreciated. Fifteen days after a dental cleaning, a mass expanding the oral mucosa of the rostral mandible was identified. An incisional biopsy revealed that the oral mucosa was infiltrated by neoplastic round-to-spindloid mesenchymal cells arranged in streams and small, dense aggregates consistent with an undifferentiated sarcoma. The patient was managed medically for approximately 6 months following the diagnosis, but, owing to declining health, euthanasia was elected and a post-mortem examination was performed. On post-mortem examination, the previously described neoplastic cells were infiltrating the rostral mandible and had metastasized to the right submandibular lymph node. Immunohistochemistry performed during the postmortem examination found that neoplastic cells were positive for Iba-1, CD18 and CD204, and negative for MUM-1, S100, Melan-A and E-cadherin, favoring a diagnosis of oral histiocytic sarcoma. Although recently recognized in cats, feline oral histiocytic sarcoma is rare, the tumor’s immunohistochemical profile is unstandardized, and the tumor’s behavior and prognosis are unclear. The diagnosis is challenging if small incisional biopsies are submitted and the neoplasm is poorly differentiated. This case report discusses the clinical, macroscopic, microscopic and immunohistochemical features of oral histiocytic sarcoma in a cat with mandibular invasion and submandibular lymph node metastasis.

Relevance and novel information

Feline primary oral histiocytic sarcoma is rare and tumor behavior and prognosis are unclear. This report broadens the immunohistochemical features of the tumor and recognizes mandibular invasion and submandibular lymph node metastasis.
Oropharynx microbiota transitions in hypopharyngeal carcinoma treatment of induced chemotherapy followed by surgery
Authors: Lau Hui-Ching , Hsueh Chi-Yao , Gong Hongli , Sun Ji , Huang Hui-Ying , Zhang Ming , Zhou Liang
Published: November 2021

Aims

To analyze changes in oropharynx microbiota composition after receiving induced chemotherapy followed by surgery for hypopharyngeal squamous cell carcinoma (HPSCC) patients.

Methods

Clinical data and swab samples of 38 HPSCC patients (HPSCC group) and 30 patients with benign disease (control group, CG) were enrolled in the study. HPSCC group was stratified into two groups: induced chemotherapy group (IC) of 10 patients and non-induced chemotherapy group (nIC) of 28 patients. The microbiota from oropharyngeal membrane was analyzed through 16S rRNA sequencing.

Results

Alpha-diversity (Shannon and Ace indexes) and weighted UniFrac based beta-diversity severely decreased in the HPSCC group when compared with CG. In pre-operative comparisons, PCoA and NMDS analyses showed microbial structures in the IC group were more similar to CG than nIC. Both IC group and nIC group yielded significantly diverse post-operative communities in contrast to their pre-operative counterparts, evident by the decrease in genera Veillonella and Fusobacterium and increase in genera Streptococcus and Gemella. Given that post-operative oropharynx microbiota showed no difference between IC and nIC groups, the IC group showed less accumulation in anaerobic communities. The abundance of genera Fusobacterium, Parvimonas, Actinomyces were enhanced in the advanced stages (III/IV).

Conclusions

Oropharynx microbiota in the HPSCC group presents dysbiosis with low diversity and abundance. Induced chemotherapy is beneficial in adjusting the oropharynx microbial environment leading to fewer amounts of anaerobe accumulation after operation. Higher amounts of Fusobacterium in advanced stages (III/IV) may influence the progression of HPSCC.
20-hydroxyeiscosatetraenoic acid may be as a predictor of malignant middle cerebral artery infarction in patients with massive middle cerebral artery infarction
Authors: Yi Xingyang , Zhou Qiang , Qing Ting , Ming Bing , Lin Jing , Li Jie , Lin Jie
Published: November 2021

Background

Early identification of massive middle cerebral artery infarction (MCAI) at risk for malignant MCAI (m-MCAI) may be useful in selecting patients for aggressive therapies. The aim of this study was to determine whether CYP metabolites may help to predict impending m-MCAI.

Methods

This is a prospective, two-center observational study in 256 patients with acute massive MCAI. Plasma levels of 20-hydroxyeicosatetraenoic acid (20-HETE), epoxyeicosatrienoic acids, and dihydroxyeicosatrienoic acids were measured at admission. Brain computed tomography (CT) was performed at admission and repeated between day 3 and 7, or earlier if there was neurological deterioration. The primary outcome was m-MCAI. The m-MCAI was diagnosed when follow-up brain CT detected a more than two-thirds space-occupying MCAI with midline shift, compression of the basal cisterns, and neurological worsening.

Results

In total of 256 enrolled patients, 77 (30.1%) patients developed m-MCAI. Among the 77 patients with m-MCAI, 60 (77.9%) patients died during 3 months of stroke onset. 20-HETE level on admission was significantly higher in patients with m-MCAI than those without m-MCAI. There was an increase in the risk of m-MCAI with increase of 20-HETE levels. The third and fourth quartiles of 20-HETE levels were independent predictors of m-MCAI (OR: 2.86; 95% CI: 1.16 – 6.68; P = 0.025, and OR: 4.23; 95% CI: 1.35 – 8.26; P = 0.002, respectively).

Conclusions

Incidence of m-MCAI was high in patients with massive MCAI and the prognosis of m-MCAI is very poor. Elevated plasma 20-HETE may be as a predictor for m-MCAI in acute massive MCAI, and it might useful in clinical practice in therapeutic decision making.
Impact of COVID-19 on radiology education in Europe: a survey by the ESR Radiology Trainees Forum (RTF)
Authors:   European Society of Radiology (ESR), Klontzas Michail E. , O’Malley Eoin , Afat Saif , Pozdniakova Viktoria , Pecoraro Martina , Catalano Carlo , Becker Minerva , Reim Martin
Published: November 2021

Background

The ongoing COVID-19 pandemic has significantly affected radiology services around the globe. The impact of the crisis on radiology education in Europe has yet to be determined, in order to identify measures to achieve optimal training of radiologists during pandemics. The aim of this survey was to evaluate the impact of the pandemic on young radiologist members of the European Society of Radiology (ESR).

Methods

A survey consisting of 28 questions was developed and distributed using SurveyMonkey to all ESR European radiologist members in training. The survey sought to collect information on three main themes, ‘demographics’, ‘training level’ and ‘effects of COVID-19’. The responses were statistically analysed with the use of R programming using descriptive statistics.

Results

A total of 249 responses from 34 countries were collected. Specific training on COVID-19 was not offered to 52.2% (130) of the participants. A total of 196 participants were not redeployed to other specialities but only 46.2% of institutions allowed residents to work from home. E-learning was offered at 43% of the departments and most participants (86.2%) were not allowed to switch from clinical work to research. A minority (n = 13) were suspended with (30.8%) or without salary (38.5%) or were forced to take vacation/yearly holiday leave (7.7%) or sick leave (23%). Almost half of the participants did not have access to personal protective equipment and a minority of them had their financial status affected.

Conclusions

The ongoing SARS-CoV-2 outbreak has significantly affected all aspects of postgraduate radiology training across the ESR member countries.
The ethics and management of cannabis use in pregnancy following decriminalisation and licensing for medical use: narrative review
Authors: Towobola Abdulazeez , Towobola Basirat , Nair Bosky , Makwana Arti
Published: November 2021

Aims and method

As drug policies pertaining to cannabis use become more liberalised, the prevalence of cannabis use in pregnancy could increase. However, there is limited guidance available for clinicians. This paper presents a narrative review of literature published in the past 16 years (2006–2021) to (a) address the impact of legalisation and decriminalisation on the risks, ethics and support of women who use cannabis during pregnancy and (b) develop guidance for clinicians.

Results

Both national and international trends suggest increased use of cannabis over the past decade, while the risks of cannabis use for recreational or medicinal purposes in pregnancy remain unmitigated.

Clinical implications

This review confirmed that the recommendation of cannabinoid-based products for pregnant and breast-feeding women is currently premature. More research is needed to address safety concerns. We discussed navigating ethical concerns and suggest targeted management strategies for clinicians treating pregnant women who choose to use cannabis.
Disparities in Tumor Mutational Burden, Immunotherapy Use, and Outcomes Based on Genomic Ancestry in Non–Small-Cell Lung Cancer
Authors: Brawley Otis W. , Luhn Patricia , Reese-White Deonna , Ogbu Uzor C. , Madhavan Sriraman , Wilson Gerren , Cox Meghan , Ewing Altovise , Hammer Christian , Richie Nicole
Published: November 2021

PURPOSE

In patients with advanced non–small-cell lung cancer (aNSCLC), tumor mutational burden (TMB) may vary by genomic ancestry; however, its impact on treatment outcomes is unclear. This retrospective, observational study describes treatment patterns of patients with aNSCLC by genomic ancestry and electronic health record (EHR)-reported race and/or ethnicity and evaluates differences in TMB, cancer immunotherapy (CIT) access, and treatment outcomes across racial and ancestral groups.

METHODS

Patients diagnosed with aNSCLC after January 1, 2011, were selected from a real-world deidentified clinicogenomics database and EHR-derived database; continuously enrolled patients were evaluated. Race and/or ethnicity was recorded using variables from the EHR database; genomic ancestry was classified by single-nucleotide polymorphisms on a next-generation sequencing panel. A threshold of 16 mutations per megabase was used to categorize TMB status.

RESULTS

Of 59,559 patients in the EHR-derived database and 7,548 patients in the clinicogenomics database, 35,016 (58.8%) and 4,392 (58.2%) were continuously enrolled, respectively. CIT use was similar across EHR-reported race groups, ranging from 34.4% to 37.3% for non-Hispanic Asian and non-Hispanic Black patients, respectively. TMB levels varied significantly across ancestry groups ( P < .001); patients of African ancestry had the highest median TMB (8.75 mutations per megabase; interquartile range, 4.35-14.79). In patients who had received CIT, high TMB was associated with improved overall survival compared with low TMB (20.89 v 11.83 months; hazard ratio, 0.60; 95% CI, 0.51 to 0.70) across genomic ancestral groups.

CONCLUSION

These results suggest that equitable access to next-generation sequencing may improve aNSCLC outcome disparities in racially and ancestrally diverse populations.
Erector Spinae Plane Continuous Catheters for Refractory Abdominal Pain Related to Necrotizing Pancreatitis: A Case Report
Authors: Allos Matthew T. , Zukowski Daniel M. , Fidkowski Christina W.
Published: November 2021

Erector spinae plane (ESP) continuous catheters are used for the management of postsurgical pain. The use of these catheters for acute nonsurgical abdominal pain is not well defined. This case describes a patient with refractory abdominal pain secondary to necrotizing pancreatitis despite escalating doses of opioids, ketamine, and dexmedetomidine. Our patient declined epidural analgesia. Bilateral ESP continuous catheters successfully controlled her pain, and she was weaned off of all analgesics during the week following catheter placement. This case demonstrates that ESP continuous catheters can be considered for patients with acute nonsurgical abdominal pain especially when thoracic epidural analgesia is contraindicated.
BENIGN TUMORS BREAST GLASS
Authors: Guseynov Arif , Guseynov T. , Odincov V.
Published: November 2021

The lecture provides relevant information for doctors of various specialties: oncologists, surgeons, mammologists, general practitioners on the problems of diagnosis and treatment of benign breast formations. The issues of etiology and pathogenesis, classification and clinical picture of various formations are highlighted, diagnostic methods, differential diagnostics, treatment tactics and methods of surgical treatment are described in detail.
The problem of pain in rheumatology
Authors: Fleyshman A.
Published: November 2021

This article discusses issues related to the classification of pain, the mechanisms of its occurrence, as well as drug and non-drug methods of its relief in rheumatological pathology.
ARE THERE STANDARDS FOR HOMEOSTASIS?
Authors: Es'kov Valeriy , Bashkatova Yuliya , Shakirova L. , Gazya G.
Published: November 2021

Some original biological researching it was presented the assent of stochastic stability of different parameters of tremorogram, cardiointervals and electromiogram for one man (within any changing of him organism). Many years ago (1947 y.) N.A. Bernstein presented special hypothesis about «repetition without repetition» for any type of movement. During 74 years nobody not presents the numerical proving of the hypothesis. Now we prove Eskov-Zinchenko effect and we must change all our presentation about standard and norm in medicine. The homeostasis is not stable state of human body. According to development of new science (theory chaos-selforganization) we presented the facts for Eskov-Zinchenko effect for biosystems. The parameters of homeostasis is not stable.
BOND STRENGTH DEGRADATION OF ADHESIVE- BONDED CFRP COMPOSITE LAP JOINTS AFTER LIGHTNING STRIKE
Authors: LIN WENHUA , WANG YEQING , LAMPKIN SPENCER , PRASAD SRIHARI GANESH , ZHUPANSKA OLESYA , DAVIDSON BARRY
Published: November 2021

Adhesive bonding to join fiber reinforced polymer matrix composites holds great promise to replace conventional mechanical attachment techniques for joining composite components. Understanding the behavior of these adhesive joints when subjected to various environmental loads, such as lightning strike, represents an important concern in the safe design of adhesively bonded composite aircraft and spacecraft structures. In the current work, simulated lightning strike tests are performed at four elevated discharge impulse current levels (71.4, 100.2, 141, and 217.8 kA) to evaluate the effects of lightning strike on the mechanical behavior of single lap joints. After documentation of the visually observed lightning strike induced damage, single lap shear tests are conducted to determine the residual bond strength. Post-test visual observation and cross-sectional microscopy are conducted to document the failure modes of the adhesive region. Although the current work was performed on a limited number of specimens, it identified important trends and directions for future more comprehensive studies on lightning strike effects in adhesively bonded composites. It is found that the lightning strike induced damage (extent of the surface vaporization area and the delamination depth) increases as the lightning current increases. The stiffness of the adhesive joints and shear bond strength did not show a clear correlation with the lightning current levels, which could be due to many competing factors, including the temperature rise caused by the lightning strike and the surface conditions of the adherends prior to bonding. The failure modes of the adhesive regions for all specimens demonstrate a mixed mode of adhesive and cohesive failure, which may be due to inconsistent surface characteristics of the adherends before bonding. The energy absorbed during the lap shear tests generally increases as the lightning current increases.
DYNAMIC RESPONSES OF ARCHITECTURAL KERF STRUCTURES
Authors: ZARYAB SHAHID, ZARYAB SHAHID, , OHNSON MOLLY  SAYLOR , BOND COLEMAN GUSTAV , HUBBARD, JR. JAMES , KALANTAR NEGAR , MULIANA ANASTASIA
Published: November 2021

Kerfing is a subtractive manufacturing approach to create flexible freeform surfaces from stiff planar materials. The kerf structures are used in both indoor and outdoor architectures for wall paneling, outdoor façade and pavilion. In addition to their physical appeal, these structures have potential applications in tuning the dynamics responses in buildings, e.g., indoor acoustic, vibration suppression, etc. To exploit these novel applications of kerf structures, this paper presents a study on the dynamic responses of kerf structures made up of Medium Density Fiberboard (MDF). MDF is a viscoelastic composite material comprising of wood fiber networks and epoxy. The influence of the material behavior, i.e. viscoelasticity of MDF is considered in determining the dynamic response of the kerf panels. Two kerf panels with similar kerfing pattern but different cut density and arrangement are studied for their modal responses. A 3D beam element is used to model the mechanical responses of the kerf panels. With the understanding of the dynamic response of these kerf panels, their applications in altering the indoor acoustics and the wind responses of the buildings can be better comprehended.
CROSS-LONGITUDINAL REINFORCEMENT STRUCTURE INSPIRED BY DRAGONFLY WING
Authors: KAWABE, HIROKI , AOKI YUICHIRO , NAKAMURA TOSHIYA
Published: November 2021

The aim of this study is to establish a novel aircraft design approach replacing the conventional airframe by utilizing biomimetics. This design approach particularly focused on the dragonfly wing, whose reinforcement structures are composed of cross- veins and longitudinal veins. The cross-veins have been emulated by weighted Centroidal Voronoi Tessellation (WCVT) following the out-of-plane displacement on the skin, while the longitudinal veins have been emulated by extracting a centerline from the topology optimization result on the skin to be reinforced, through image analysis of binarization and skeletonization. The longitudinal layout can reduce the compliance distributing the inner load with only essential reinforcement on the skin without increasing the mass. The weighted CVT layout can improve the effectiveness of the reinforced skin against buckling drastically. Thus, the skin reinforced along the cross- longitudinal layout by the topology optimization and weighted CVT pattern increased buckling load 2.7 times higher even with less mass than the conventional layout.
INFLUENCE OF CARBON IN LEAD MATRIX FOR LEAD ACID BATTERY APPLICATION: A DENSITY FUNCTIONAL THEORY APPROACH
Authors: YANAMANDRA KAUSHIK , BEHERA RAKESH K. , GUPTA NIKHIL
Published: November 2021

Recent research in developing novel lead electrodes composed of carbon and lead composites have shown potential of increasing the ability of lead-acid batteries to store energy in grid scale applications but many technical challenges persist. One challenging obstacle is that influence of carbon on lead matrix in these new battery systems are obscure and the mechanism taking place at the atomic level is difficult to investigate experimentally. However, a better understanding of the working mechanisms of battery materials is crucial for developing new advanced batteries toward industrial applications. In this paper the density functional theory (DFT) calculation are carried out using the Vienna Ab-initio Simulation Package (VASP) with spin-polarized generalized gradient approximation (GGA) functional parametrized by Perdew, Burke, and Enrzerhof (PBE) is used to describe the exchange and correlation energies of the electrons. Herein, a systematic increase in system site with decrease in C concentration was investigated in Pb using DFT. This study provides vital fundamental data on Pb-C structure such as density of states, band structures, defect formation energies.
IMPACT DAMAGE DETECTION IN COMPOSITE AEROSPACE STRUCTURES BY MULTI-RESOLUTION NDE INSPECTIONS
Authors: CAPRIOTTI MARGHERITA , ELLISON ANDREW , KIM HYUNGSUK E. , SCALEA FRANCESCO LANZA DI , KIM HYONNY
Published: November 2021

Assessing the health of aerospace structures and understanding the underlying mechanics that govern composite strength constitute a main focus of research in the area of aerospace design and airworthiness certification. Impact damage is one of the major threats to composite aerospace structures for its frequency of occurrence, complexity and minimum external visibility. While non-destructive evaluation (NDE) provides a variety of solutions to inspect the subsurface and internal components of structures non-invasively, a gap exists between the mechanics of damage formation, growth and tolerance, and the inspectability of the structure. This study is focused on the quantitative correlation between impact damage mechanics and ultrasonic NDE inspections, where damage severity, mode interaction and progression are identified in real-scale composite panels of complex geometry, representative of commercial aircraft, impacted to reproduce different damage types at the skin-to-stringer interface and the stringer cap. High resolution X-ray CT scanning and conventional ultrasonic scanning (UT) have been used to map the damage state and identify relevant impact damage features. Ultrasonic guided wave (UGW) scanning was then employed as a rapid in-situ inspection technique to not only detect damage but also provide quantitative information about damage severity and mode. The correlation of multi-resolution multi-dimensional NDE data promises new insights on damage studies and solutions to damage detection and prognosis through viable NDE inspections.
PERIDYNAMIC UNIT CELL ENABLED FINITE ELEMENT MODELING OF FIBER STEERED COMPOSITES
Authors: MADENCI, ERDOGAN , BARUT ATILA , PHAN NAM , GURDAL ZAFER
Published: November 2021

This study presents an approach based on traditional finite elements and peridynamic unit cell (PDUC) to perform structural analysis of fiber steered composite laminates. Effective material property matrix for each ply in the plate element is computed by employing the PDUC based on the orientation of the fiber path and orthotropic ply properties. Each element defines the unit cell domain if the element shape is rectangular. Otherwise, the rectangle that circumscribes the element defines the domain of the unit cell. The element stiffness matrix is constructed through a traditional finite element implementation. This approach provides an accurate and simple modeling of variable angle tow laminates. It can be readily integrated in commercially available finite element programs.
HIGH ENERGY WIDE AREA BLUNT IMPACT OF COMPOSITE AIRCRAFT STRUCTURES—PART A: DESIGN AND ANALYSIS METHODOLOGY OF REPRESENTATIVE SUBSTRUCTURE
Authors: SOUZA CHAIANE  WIGGERS DE , NAM MOONHEE , KIM HYONNY
Published: November 2021

Large test structures, common in the aerospace industry, offer a challenge to model, manufacture and test, with high cost associated with computational as well as materials, specimen fabrication, test planning/setup, and instrumentation resources. In this paper, a methodology is presented to demonstrate use of a smaller-sized substructure to produce equivalent response to the original, larger structure. The structure under study is a quarter barrel of typical commercial aircraft fuselage section made of carbon fiber reinforced polymer (CFRP), initially consisting of two circumferential structural members (C-frames and shear ties), and 12 stringers cocured to the skin. Through a series of finite element analyses and a modified specimen design, a substructure representing the quarter barrel was validated for loading conditions generated by high energy wide area blunt impacts (HEWABI) which are potentially caused by accidental contact from moving ground service equipment (GSE). The substructure is made of one circumferential member (C-frame and shear tie), and 6 stringers co-cured to skin and is shown to have similar stiffness and stresses in the region of interest. Finite element analysis (FEA) with progressive damage analysis demonstrates the equivalent response between the substructure and full quarter barrel. This methodology can be used in a wide range of applications, as long as the loading area is distant enough from the modified structure end and the correct boundary conditions/fixtures are defined to represent the omitted portions of the structure of interest.
Quantile Markov Decision Processes
Authors: Li Xiaocheng , Zhong Huaiyang , Brandeau Margaret L.
Published: November 2021

Title: Sequential Decision Making Using Quantiles

The goal of a traditional Markov decision process (MDP) is to maximize the expectation of cumulative reward over a finite or infinite horizon. In many applications, however, a decision maker may be interested in optimizing a specific quantile of the cumulative reward. For example, a physician may want to determine the optimal drug regime for a risk-averse patient with the objective of maximizing the 0.10 quantile of the cumulative reward; this is the cumulative improvement in health that is expected to occur with at least 90% probability for the patient. In “Quantile Markov Decision Processes,” X. Li, H. Zhong, and M. Brandeau provide analytic results to solve the quantile Markov decision process (QMDP) problem. They develop an efficient dynamic programming procedure that finds the optimal QMDP value function for all states and quantiles in one pass. The algorithm also extends to the MDP problem with a conditional value-at-risk objective.
THE INFLUENCE OF THE COVID-19 PANDEMIC ON ALLOCATION OF ASSETS IN INVESTORS PORTFOLIO
Authors: Bobulský Maroš , Bohdalová Mária
Published: November 2021

Investing during a pandemic is very challenging. Even in these difficult times, the investor must appropriately allocate assets into his portfolio. In this article, we discuss investing in the stock market. We are interested in creating portfolios of shares that consist of financial assets. The individual methods we use are designed to provide an allocation of funds in between individual shares.  In the modern portfolio theory, the Markowitz model (Markowitz, 1952) is being used to solve these problems. The paper's main goal is to propose an efficient, robust approach to solve the Markowitz optimization problem adjusted for periods of a global decline in financial markets. In our research, we focus on robust optimization. Instead of precisely given input parameters, we propose a set of parameters from which we always select the worst possible parameter (so-called worst-case optimization). The robustness of optimization is achieved using so-called filter matrices. These matrices are used to modify historical data directly during optimization. The proposed model modifies the data by using different lengths of historical returns. Our proposed model is then compared with the original Markowitz non-robust model. We compare these two models using the properties of the second derivative of the optimization problem. Our results are visualized for different levels of investor’s risk aversion. We present our methods on historical price data of five randomly selected companies traded on the US market. By comparing the proposed robust approach with the non-robust one, we show that different lengths of historical returns capture volatility changes earlier. The investor can thus reduce his risk aversion and increase his expected returns.
FUZZY AGGREGATION FOR RANKING IN BUSINESS
Authors: Rakovská Eva
Published: November 2021

Today, businesses depend strongly on data and the opinion of customers or the experience of managers or experts. The large databases contain non-heterogeneous data, which is the ground for further decisions. Business uses multicriterial decisions in more areas (e.g., customer care, marketing, product development, risk management, HR, etc.) and often it is based on assessment. One of the assessment methods is the ranking, which can be done by crisp values of data where the sharp borders between evaluated entities do not give the adequate ranking result. On the other hand, the ranking process is based on the qualitative assessment, which has linguistic expression. It is more familiar and understandable for people. The article shows how to treat non-heterogeneous data to prepare them for a ranking process using fuzzy sets theory. The article aims at offering several types of ranking methods based on different inputs and preferences of the user and describes appropriate fuzzy aggregations for solving the ranking problem.
THE RELATIONSHIP BETWEEN JOB SATISFACTION AND INDIVIDUAL PERFORMANCE OF IT EMPLOYEES
Authors: Yanchovska Irina
Published: November 2021

Purpose – The main purpose of this research paper is to investigate the correlation between job satisfaction of employees in the IT sector and their personal performance. Additionally, the study examines the overall level of employee satisfaction, as well as if job satisfaction levels differ significantly among the studied demographic groups.

Design/methodology/approach – The research is based on quantitative analysis of data collected through a questionnaire containing answers of 126 international respondents from over 25 different IT companies. The research methods used are one-dimensional methods for preliminary analysis, Cronbach alpha for reliability and consistency, one-way ANOVA for mean values comparison and correlation analysis for examining relationships.

Findings – The findings show a moderate statistically significant correlation between job satisfaction and employees’ personal performance, which is bidirectional as influence and  presumably depends on other variables like work engagement, motivation, stress or exhaustion, which were not examined in the current study. Additionally, most of the employees in the researched sample define themselves as satisfied with their jobs. Statistically significant variation of the mean job satisfaction levels was observed in two of the examined demographic variables – gender and years in the current position.

Practical implications – The research results can be beneficial for different organizations since job satisfaction is important for employees’ long-term retention, for increasing their commitment and loyalty towards the organization, as well as for the creation of a motivating and productive work environment. Employees’ job satisfaction and their personal performance should always be considered main organizational values and key for achieving excellent business results and market leadership.

Originality/value – The results of the current research are important for validating the position of these researchers, who claim that a positive correlation between an employees’ job satisfaction and their personal performance in the workplace exists and should not be neglected. Additionally, it contributes towards a better understanding of job satisfaction among IT employees.
STUDENTS’ VIEWS ON THE ROLE OF ETHICS EDUCATION FOR THEIR FUTURE MEDICAL PRACTICE
Authors: Leventi Nikoleta , Vodenitcharova Alexandrina , Popova Kristina , Ivanova Kremena , Georgiev Svetlin , Yanakieva Antoniya
Published: November 2021

INTRODUCTION: Worldwide, in different ways, ethical dilemmas arise in medicine and life sciences. It is critical for medical professionals to respond with confidence when ethical challenges are addressed in their clinical practice. Medical ethics and bioethics education is recognized as an essential course of the medical curriculum. The course aims to provide students with knowledge and competencies on dealing with moral problems.

OBJECTIVES: In this article, we aim to explore students’ views about the importance and role of medical ethics education for their future practice. Their suggestions on specific medical ethics and bioethics topics were also considered, as well as previous knowledge on ethics before they enrolled in university.

METHODS: A paper questionnaire was developed and distributed among first-year foreign medical students from the Faculty of Medicine in the Medical University-Sofia in Bulgaria. All students participated in the study anonymously and voluntarily. The study was conducted during January and February 2020.

RESULTS: Completed questionnaires were received from 366 medical students. Data collected demonstrates that only 19% of the students were taught ethics before enrolling in university and covered topics on philosophy and ethics, civil and human rights. The majority (92%) of the responders believe that the study of medical ethics and bioethics helps medical professionals to improve their skills in identifying ethical problems in their everyday practice. Interesting were the suggestions for topics in medical ethics and bioethics that needed further study during lectures and seminars and included principles of medical ethics and bioethics, ethical behavior in medicine and health care, ethical dimensions of new technologies in health care, ethical dimensions of clinical decisions and patients’ quality of life, ethics and health management.

CONCLUSIONS: Medical ethics education is significant for future physicians, helping them to improve their skills in identifying ethical issues, and base their decisions on fundamental ethical principals in their everyday practice. Attention should be given to topics related to principles of medical ethics, models of patient-physician relationships, new technologies in health care, ethics and health policy.
IS ANYBODY KEEPING THE CODE IN BULGARIA? A STUDY TO EXPLORE LOCAL PARENTS' AWARENESS REGARDING THE INTERNATIONAL CODE FOR THE MARKETING OF BREAST-MILK SUBSTITUTES.
Authors: Serbezova Ivanichka , Lyutakova Daniela
Published: November 2021

This paper reviews Bulgarian parents’ awareness concerning the existence of the WHO Code for the marketing of breast-milk substitutes and how it can help them optimize their breastfeeding journey. Frequently occurring problems and breaches of the Code in Bulgaria are discussed, and their context explained. We focus on parental attitudes and investigate whether they acknowledge the significant necessity for a Code-compliant prenatal education and postnatal care. We also explore their viewpoints on the implementation of the Code and maximizing compliance with it on a local level. The research findings are presented graphically, and we present tendencies showcased by respondents’ opinions they have expressed in the survey.

OBJECTIVES: Purposes of this research are: (1) to explore parents’ awareness about the WHO Code and their encounter with local prenatal classes in this regard (2) to assess their viewpoints on implementing the Code and if they see it as a significant step towards an optimal breastfeeding experience.

METHODS: The methods we applied include an online-based cross-sectional semi-quantitative questionnaire with closed-ended and open-ended questions, aiming to explore parents’ current knowledge and viewpoints in regard to the Code and its implementation in Bulgaria. The research has been carried out via social media, and it samples parents from a local parent peer support group. Acquired data from closed-ended questions is presented, demonstrating percentages and tendencies.

RESULTS: A total of 463 respondents are included

CONCLUSION: It is a common practice in Bulgaria for prenatal classes not to comply with the WHO Code. Disregarding recommendations and evidence-based medicine, both some experts and companies under the scope of the Code breach its main points. Code-compliant prenatal education is practically almost non-existent with the lack of midwife-led care and classes, predominantly in the private sector, where they are almost entirely, sponsored by those companies. Nearly all parents included in this survey are more than willing and motivated to have access to Code-compliant prenatal education and postnatal care. The lack of such leaves almost no choice for Bulgarian parents actually to have access to code-compliant education and care. This inevitably influences their decision making, attitudes and behavior, potentially leading to lower breastfeeding rates and suboptimal breastfeeding satisfaction and success. Adequate measures must be reinforced to ensure implementation and proper legislation, providing monitoring and enforcement, protecting parents and their babies when they are most vulnerable.
CLINICALLY EVALUATED ACCURACY OF SINGLE GUIDED IMPLANTATIONS WITH TWO DIFFERENT SYSTEMS – PRELIMINARY RESULTS
Authors: Vlahova Angelina , Zlatev Stefan , Pavlov Boyan , Chenchev Ivan , Hadzhigaev Viktor
Published: November 2021

Introduction: Guided single implant placement ensures an optimal implant position, enables in-surgery immediate loading, and creates a predisposition for predictable treatment results.

Aim: This article aims to present the surgical and loading protocols and assess the accuracy of two guided implant systems.

Materials and methods: Ten patients missing a single molar were included. The semi-guided procedures with the two implant systems – AB Dental and Alpha Bio-Tec, were randomly assigned to each participant. The computer-assisted planning was performed with Implant Studio (3Shape, Denmark). Surgical guides and long-term, temporary, screw-retained restorations were virtually generated within the 3Shape system. Surgical appliances were printed from SG resin (Formlabs, USA), and crowns were milled from Telio CAD (Ivoclar Vivadent, Lichtenstein). Planning accuracy was evaluated based on the crown’s fit and relation to the adjacent teeth and antagonists.

Results and discussion: The patients included for preliminary analysis (6 female and 4 male) were with a mean age of 33.42. The youngest was 24, and the oldest 49 years old. There were no surgical and technical complications for the period of evaluation, which ranged from 1 to 3 months. The crown’s fit was excellent in 8 cases. In two cases, minor adjustments were necessary – 1 in relation to the antagonists and 1 to the adjacent teeth. In one case, a healing screw was placed for 48 hours to facilitate adequate soft-tissue space for the Ti-base. 

Conclusion: The preliminary results presented in this report suggest that the clinical and laboratory protocols used for guided implantation and immediate loading are highly efficient.
A SURVEY OF E-COMMERCE SECURITY THREATS AND SOLUTIONS
Authors: Dakov Stanislav , Malinova Anna
Published: November 2021

E-commerce security is part of the Web security problems that arise in all business information systems that operate over the Internet. However, in e-commerce security, the dimensions of web security – secrecy, integrity, and availability-are focused on protecting the consumer’s and e-store site’s assets from unauthorized access, use, alteration, or destruction. The paper presents an overview of the recent security issues in e-commerce applications and the usual points the attacker can target, such as the client (data, session, identity); the client computer; the network connection between the client and the webserver; the web server; third party software vendors. Discussed are effective approaches and tools used to address different e-commerce security threats. Special attention is paid to Cross-Site Scripting (XSS), Cross-Site Request Forgery (CSRF), phishing attacks, SQL injection, Man-in-the-middle, bots, denial-of-service, encryption, firewalls, SSL digital signatures, security certificates, PCI compliance. The research outlines and suggests many security solutions and best practices.
RAPID MATERIALIZATION OF A SMALL SERIES OF BONE STRUCTURE REPLICATIONS FROM A DIGITALIZED MODEL, CREATED BY COMPUTER TOMOGRAPHY
Authors: Gavrilov Todor , Todorov Georgi , Sofronov Yavor
Published: November 2021

The recreation of bone structures from the human body has very complex geometry and a lack of symmetry. A small series of vertebrae replications, digitized by computed tomography, could serve in exercises for medical students to help them perform operational planning for inserting implant structures, cage type implants, or screws and rods implants. Additionally, these replications could be used in the planning of extraordinary clinical cases, for example complex vertebrae deformities. The replicated structure could be fulfilled in a 1:1 ratio or scaled. For the selection of an appropriate production technology a block diagram is followed which considers suitable technologies for the production of polymer parts, compared to the series size and the complexity of the geometry. Both criteria must be taken into account when considering which technology should be used in the production of polymer parts. Comparing the advantages and disadvantages of additive technologies and replication in silicone mold, the best choice for technology is set to be replication in silicone mold. The initial preparation for the manufacture of the silicone mold includes a detailed analysis of the geometry of the model for replication. The first step includes defining the runner place as well as mounting the runner to the model. To ensure the mold is completely filled while casting, positive-shaped vents in the mold are defined. Because of the complex shapes of the spinal vertebrae and the need to take out elements in many directions, the mold is divided into multiple parts. A block-diagram that summarizes the entire manufacturing cycle for replication in a silicone mold is developed.
MODEL-ORIENTED PROGRAMMING
Authors: Kruglov Leonid , Brodsky Yury
Published: November 2021

The problem of complex multi-component system processing arises in many fields of science and engineering. A system can be described in terms of its components, behavior, and interaction. This work proposes a new declarative Turing complete “model-oriented” programming paradigm based on the concept of “model-component” - a complex structure with well-defined characteristics and behavior, and no external methods. The set of model-components is closed under the union operation of model-components into “model-complex”. The proposed approach allows the program to describe the complex system and behavior of its components in a declarative way, possesses a higher level of encapsulation than the object-oriented paradigm, involves a reduced amount of imperative programming, and is naturally focused on parallel computations.
LINGUISTIC SUMMARIES IN EVALUATING ELEMENTARY CONDITIONS AND THEIR APPLICATION IN SOFTWARE ENVIRONMENT
Authors: Sojka Pavol
Published: November 2021

Data users are generally interested in two types of aggregated information: summarization of the selected attribute(s) for all considered entities and retrieval and evaluation of entities by the requirements posed on the relevant attributes. Less statistically literate users (e.g., domain experts) and the business intelligence strategic dashboards can benefit from linguistic summarization, i.e. a summary like most customers are middle-aged can be understood immediately. Evaluation of the mandatory and optional requirements of the structure P1 and most of the other posed predicates should be satisfied beneficial for analytical business intelligence dashboards and search engines in general. This work formalizes the integration of the aforementioned quantified summaries and quantified evaluation into the concept of database queries to empower their flexibility by, e.g., the nested quantified query conditions on hierarchical data structures. Later in our work, we adapted our research into practical application. We created a software environment for evaluating data based on a dataset retrieved from The Statistical Office of the Slovak republic. These datasets are aimed mainly on landscape characteristics like altitude, area sizes of towns and villages, and similar parameters. Based on user's preferences, our system recommends the most suitable place for holidays to spend on.
ATTITUDES TOWARDS SAME-SEX PARTNERSHIP: A SOCIOLOGICAL RESEARCH OF YOUNG PEOPLE IN SPLIT (CROATIA)
Authors: Bandalović Gorana , Šuljug Vučica Zorana , Uvodić Ines
Published: November 2021

One of the current dilemmas of modern society is how to look at homosexuals, same-sex partners, forming same-sex partnerships, and raising children in such communities. Homosexuals are classified as sexual minorities and are often excluded from society, which is not new because members of sexual minorities have long been accompanied by numerous persecutions and repressions. This paper aims to examine the attitudes of young people towards homosexuality and same-sex partnership. The paper presents the results of the research conducted in 2019 using a survey method on a sample of 303 respondents aged 15 to 35 years. The results show that most young people do not consider homosexuality to be a disease and approach LGBT people in the same way as the rest of society, not paying attention to someone's sexual orientation. Respondents are predominantly open to the possibility of marriage between same-sex partners while they to a lesser extent agree with the adoption and upbringing of children by same-sex partners. They believe that there is a difference in the upbringing of children raised by same-sex partners from children raised by heterosexual partners, which can be justified by the discrimination and violence to which children of same-sex partners are exposed to. Also, young people think that homosexual parents can be good parents and provide their children with everything they need and that it is better for children to grow up in same-sex families than in homes for abandoned children. Although they state that such communities are almost equal to heterosexual communities, they are aware of their exposure to social exclusion.