bluuebunny/crossref_metadata_2025 huggingface dataset:
Operator’s eye lens dose in computed tomography–guided interventions
Authors: Kaartinen Siru , Husso Minna , Matikka Hanna
Published: December 2020

Objectives

To survey (1) operator’s eye lens doses in typical computed tomography (CT)-guided interventions, (2) correlation between dose length product (DLP) and the operator’s dose, and (3) different ways for estimating the eye lens dose in clinical settings.

Methods

Doses of 16 radiologists in 164 CT-guided interventional procedures were prospectively measured during a 6-month time period upon radioprotective garments and descriptive statistical outcomes were calculated. The correlations between DLP and measured doses were surveyed.

Results

On average, the operator’s dose at the eye level (DEL, Hp(0.07)) was 22 μSv per procedure and the personal equivalent dose Hp(10) at the collar level was 21 μSv per procedure. The mean DLP of a procedure was 320 mGy cm, where 54% resulted from the fluoroscopy, the mean exposure time being 18 s. Based on the results, the operator’s DEL could be estimated from DLP using the equation DEL (μSv) = 0.10 μSv/mGy cm × patient fluoro DLP (mGycm) (p < 0.001), and the dose at the collar level (DCL) using the equation DCL (μSv) = 0.12 μSv/mGy cm × patient fluoro DLP (mGy cm) (p < 0.001). In addition, DEL (μSv) = 0.7 × DCL (μSv).

Conclusions

The eye lens doses in CT-guided interventions are generally low even without protective equipment, and it is unlikely that the recommended annual equivalent dose limit of 20 mSv for the lens of the eye will be exceeded by conducting CT-guided interventions solely. Eye lens dose can be roughly estimated based on either DLP of the procedure or dose measured at the operator’s collar level.

Key Points

• Eye lens doses in CT-guided operations are generally low.

• It is unlikely that the ICRP recommendation of the yearly equivalent dose limit of 20 mSv will be exceeded by conducting CT-guided interventions solely.

• Magnitude of eye lens dose can be estimated based on either DLP of the procedure or dose measured at the operator’s collar level.
Improving quality of life through the routine use of the patient concerns inventory for head and neck cancer patients: main results of a cluster preference randomised controlled trial
Authors: Rogers Simon N. , Allmark Christine , Bekiroglu Fazilet , Edwards Rhiannon Tudor , Fabbroni Gillon , Flavel Robert , Highet Victoria , Ho Michael W. S. , Humphris Gerald M. , Jones Terry M. , Khattak Owais , Lancaster Jeffrey , Loh Christopher , Lowe Derek , Lowies Cher , Macareavy Dominic , Moor James , Ong T. K. , Prasai A. , Roland Nicholas , Semple Cherith , Spencer Llinos Haf , Tandon Sank , Thomas Steven J. , Schache Andrew , Shaw Richard J. , Kanatas Anastasios
Published: December 2020

Purpose

The patient concerns inventory (PCI) is a prompt list allowing head and neck cancer (HNC) patients to discuss issues that otherwise might be overlooked. This trial evaluated the effectiveness of using the PCI at routine outpatient clinics for one year after treatment on health-related QOL (HRQOL).

Methods

A pragmatic cluster preference randomised control trial with 15 consultants, 8 ‘using’ and 7 ‘not using’ the PCI intervention. Patients treated with curative intent (all sites, disease stages, treatments) were eligible.

Results

Consultants saw a median (inter-quartile range) 16 (13–26) patients, with 140 PCI and 148 control patients. Of the pre-specified outcomes, the 12-month results for the mean University of Washington Quality of Life (UW-QOLv4) social-emotional subscale score suggested a small clinical effect of intervention of 4.6 units (95% CI 0.2, 9.0), p = 0.04 after full adjustment for pre-stated case-mix. Results for UW-QOLv4 overall quality of life being less than good at 12 months (primary outcome) also favoured the PCI with a risk ratio of 0.83 (95% CI 0.66, 1.06) and absolute risk 4.8% (− 2.9%, 12.9%) but without achieving statistical significance. Other non-a-priori analyses, including all 12 UWQOL domains and at consultant level also suggested better HRQOL with PCI. Consultation times were unaffected and the number of items selected decreased over time.

Conclusion

This novel trial supports the integration of the PCI approach into routine consultations as a simple low-cost means of benefiting HNC patients. It adds to a growing body of evidence supporting the use of patient prompt lists more generally.
Maintaining Equity and Access: Successful Implementation of a Virtual Kidney Transplantation Evaluation
Authors: Rohan Vinayak S. , Pilch Nicole , Cassidy Deborah , McGillicuddy John , White Jared , Lin Angello , Nadig Satish N. , Taber David J. , Dubay Derek , Baliga Prabhakar K.
Published: December 2020

BACKGROUND:

Maintaining access to kidney transplantation during a pandemic is a challenge, particularly for centers that serve a large rural and minority patient population with an additional burden of travel. The aim of this article was to describe our experience with the rollout and use of a virtual pretransplantation evaluation platform to facilitate ongoing transplant waitlisting during the early peak of the COVID-19 pandemic.

STUDY DESIGN:

This is a retrospective analysis of the process improvement project implemented to continue the evaluation of potential kidney transplantation candidates and ensure waitlist placement during the COVID-19 pandemic. Operational metrics include transplantation volume per month, referral volume per month, pretransplantation patients halted before completing an evaluation per month, evaluations completed per month, and patients waitlisted per month.

RESULTS:

Between April and September 2020, a total of 1,258 patients completed an evaluation. Two hundred and forty-seven patients were halted during this time period before completing a full evaluation. One hundred and fifty-two patients were presented at selection and 113 were placed on the waitlist. In addition, the number of patients in the active referral phase was able to be reduced by 46%. More evaluations were completed within the virtual platform (n = 930 vs n = 880), yielding similar additions to the waitlist in 2020 (n = 282) vs 2019 (n = 308) despite the COVID-19 pandemic.

CONCLUSIONS:

The virtual platform allowed continued maintenance of a large kidney transplantation program despite the inability to have in-person visits. The value of this platform will likely transform our approach to the pretransplantation process and provides an additional valuable method to improve patient equity and access to transplantation.
Understanding the full cost of cyber security breaches
Authors: Furnell Steven , Heyburn Harry , Whitehead Andrew , Shah Jayesh Navin
Published: December 2020

Media reports regularly highlight organisations that have experienced costly cyber attacks or other cyber security breaches. Such breaches can have far-reaching and long-running impacts, compromising systems and data, impacting relationships with customers, suppliers and partners, and in extreme situations becoming existential threats. As an example of the potentially significant costs involved, the cyber attack on TalkTalk, the UK telecommunications company, in 2016, is estimated to have cost up to £60m. 1

When organisations are breached, many will recognise that they have been impacted in some way. But new research suggests that organisations rarely understand the full cost.

Steven Furnell of the University of Nottingham and Harry Heyburn, Andrew Whitehead and Jayesh Navin Shah at Ipsos MORI examine the range of potential direct and indirect costs organisations can incur, and the varying timeframes over which these costs come to light. And they offer a data collection tool that can support organisations to fully capture the cost of breaches.
Prevalence of malnutrition in coronavirus disease 19: the NUTRICOV study
Authors: Rouget Antoine , Vardon-Bounes Fanny , Lorber Pierre , Vavasseur Adrien , Marion Olivier , Marcheix Bertrand , Lairez Olivier , Balardy Laurent , Fourcade Olivier , Conil Jean-Marie , Minville Vincent
Published: December 2020

Recent European Society of Parenteral and Enteral Nutrition guidelines highlighted the interest of prevention, diagnosis and treatment of malnutrition in the management of coronavirus disease 19 (COVID-19) patients. The aim of our study was to evaluate the prevalence of malnutrition in patients hospitalised for COVID-19. In a prospective observational cohort study malnutrition was diagnosed according to the Global Leadership Initiative on Malnutrition (GLIM) two-step approach. Patients were divided into two groups according to the diagnosis of malnutrition. Covariate selection for the multivariate analysis was based on P <0·2 in univariate analysis, with a logistic regression model and a backward elimination procedure. A partitioning of the population was realised. Eighty patients were prospectively enrolled. Thirty patients (37·5 %) had criteria for malnutrition. The need for intensive care unit admission (n 46, 57·5 %) was similar in the two groups. Three patients who died (3·75 %) were malnourished. Multivariate analysis exhibited that low BMI (OR 0·83, 95 % CI 0·73, 0·96, P = 0·0083), dyslipidaemia (OR 29·45, 95 % CI 3·12, 277·73, P = 0·0031), oral intake reduction <50 % (OR 3·169, 95 % CI 1·04, 9·64, P = 0·0422) and glomerular filtration rate (Chronic Kidney Disease Epidemiology Collaboration; CKD-EPI) at admission (OR 0·979, 95 % CI 0·96, 0·998, P = 0·0297) were associated with the occurrence of malnutrition. We demonstrate the existence of a high prevalence of malnutrition in a general cohort of COVID-19 inpatients according to GLIM criteria. Nutritional support in COVID-19 care seems an essential element.
‘She shouldn't cross the line’: experiential effectivity of social guidance trajectories for socially isolated older adults with complex problems
Authors: Machielse Anja
Published: December 2020

Social isolation of older adults is difficult to break through, and interventions that focus on network development or enhanced social participation are hardly effective, especially when the older adults have been isolated for a long time and have problems in multiple life domains. This study aimed to investigate the needs and subjective experiences of this less-researched group and obtain a deeper understanding of their goals and priorities. The study involved a qualitative study with 25 socially isolated persons who receive assistance from a social worker in an individual guidance trajectory. Data were collected via repeated in-depth interviews with the older adults. By directing the focus towards their subjective experiences, the study gives insight into the ‘experiential effectivity’ of the intervention. It shows what their experienced problems were, and to what degree they benefited from the intervention in this respect. The experience of personal attention and involvement of the social workers represents the most relevant results for them. The participants have no need for network development or engagement in local communities. Yet, the help offered by the social workers produces other results for them, such as solved practical problems, emotional support, more self-sufficiency, a point of contact or a safety net that was not there before. This knowledge can help to improve the quality of intervention for this target group.
The Relationship between Negative Symptoms and Both Emotion Management and Non-social Cognition in Schizophrenia Spectrum Disorders
Authors: Yolland Caitlin O. B. , Carruthers Sean P. , Toh Wei Lin , Neill Erica , Sumner Philip J. , Thomas Elizabeth H. X. , Tan Eric J. , Gurvich Caroline , Phillipou Andrea , Van Rheenen Tamsyn E. , Rossell Susan L.
Published: December 2020

Objective:

There is ongoing debate regarding the relationship between clinical symptoms and cognition in schizophrenia spectrum disorders (SSD). The present study aimed to explore the potential relationships between symptoms, with an emphasis on negative symptoms, and social and non-social cognition.

Method:

Hierarchical cluster analysis with k-means optimisation was conducted to characterise clinical subgroups using the Scale for the Assessment of Negative Symptoms and Scale for the Assessment of Positive Symptoms in n = 130 SSD participants. Emergent clusters were compared on the MATRICS Consensus Cognitive Battery, which measures non-social cognition and emotion management as well as demographic and clinical variables. Spearman’s correlations were then used to investigate potential relationships between specific negative symptoms and emotion management and non-social cognition.

Results:

Four distinct clinical subgroups were identified: 1. high hallucinations, 2. mixed symptoms, 3. high negative symptoms, and 4. relatively asymptomatic. The high negative symptom subgroup was found to have significantly poorer emotion management than the high hallucination and relatively asymptomatic subgroups. No further differences between subgroups were observed. Correlation analyses revealed avolition-apathy and anhedonia-asociality were negatively correlated with emotion management, but not non-social cognition. Affective flattening and alogia were not associated with either emotion management or non-social cognition.

Conclusions:

The present study identified associations between negative symptoms and emotion management within social cognition, but no domains of non-social cognition. This relationship may be specific to motivation, anhedonia and apathy, but not expressive deficits. This suggests that targeted interventions for social cognition may also result in parallel improvement in some specific negative symptoms.
Cruising Utopia with Brittany Howard:Jaime's Queer Afrofuturism
Authors: ROYSTER FRANCESCA T.
Published: December 2020

Inspired by Brittany Howard's solo albumJaime(2019), this contribution creates a conversation between music studies, queer studies, African American Literature, and memoir to think about lived ways of understanding, performing, and participating in music to create a future of inclusion. I argue that Black queer strategies of listening and musicking contributes to a new layer of music, the dream space, which helps us understand the impact of music on everyday life.
The Politics of Part-Time Work: Gender, Employment Status, and Preferences for Redistribution
Authors: Pedulla David S. , Donnelly Michael J.
Published: December 2020

The social and economic forces that shape attitudes toward the welfare state are of central concern to social scientists. Scholarship in this area has paid limited attention to how working part-time, the employment status of nearly 20% of the U.S. workforce, affects redistribution preferences. In this article, we theoretically develop and empirically test an argument about the ways that part-time work, and its relationship to gender, shape redistribution preferences. We articulate two gender-differentiated pathways—one material and one about threats to social status—through which part-time work and gender may jointly shape individuals’ preferences for redistribution. We test our argument using cross-sectional and panel data from the General Social Survey in the United States. We find that the positive relationship between part-time employment, compared to full-time employment, and redistribution preferences is stronger for men than for women. Indeed, we do not detect a relationship between part-time work and redistribution preferences among women. Our results provide support for a gendered relationship between part-time employment and redistribution preferences and demonstrate that both material and status-based mechanisms shape this association.
How do Employees Adapt to Organizational Change? The Role of Meaning-making and Work Engagement
Authors: van den Heuvel Machteld , Demerouti Evangelia , Bakker Arnold B. , Hetland Jørn , Schaufeli Wilmar B.
Published: December 2020

This multi-wave, multi-source study focuses on the benefits of work engagement for employee adaptation to organizational change. The change entailed the implementation of a flexible office design in an engineering firm, which caused radical change for employees. Building on conservation of resources (COR) theory and change transition models, we predict that work engagement trajectories during change are crucial for successful adaptation. The hypothesized process was that initial employee meaning-making will facilitate work engagement, which, in turn, predicts supervisor-rated adaptive performance (i.e. adaptive work-role performance and extra-role performance) via attitude-to-change. Attitude-to-change was modeled as reciprocally related to work engagement at different points in time. Weekly questionnaires were completed by 71 employees during the first five weeks of the change (296 observations). Latent growth trajectories using weekly engagement measures showed no overall growth, but did show significant variance around the slope of work engagement. Meaning-making and attitude-to-change at the onset were positively related to initial levels, but not to growth of work engagement. Meaning-making was indirectly related to short-term attitude-to-change via work engagement. Short-term attitude-to-change was predictive of supervisor-rated adaptive performance and long-term attitude-to-change. Finally, work engagement (slope) predicted long-term attitude-to-change and supervisor-rated extra-role performance via short-term attitude-to-change. Taken together, the study contributes to knowledge about micro-level transition processes of employee adaptation and the benefits of work engagement during change.
BetweenFaqīrandFankār? Sounding Complex Subjectivities through Shah Jo Rāg in Sindh, Pakistan
Authors: HUANG PEI-LING
Published: December 2020

Rāgī faqīrsare devotees who perform Shah Jo Rāg, a musical tradition for singing Sufi poetry at the shrine of poet-mystic Shāh ‘Abdul Latīf Bhiṭṭāī (1689–1752) in Sindh, Pakistan. Focusing on the life experiences of my teacher Manthār Faqīr, I historicise various subject positions that contemporaryrāgī faqīrsrefer to asfaqīr(devotee),fankār(performing artist),kārīgar(skilled artisan), and artist. Through Manthār Faqīr’s performances, I analyse sonic manifestations of his complex subjectivities that at times shift, at times coexist, to demonstrate how he deploys sounded strategies emerging from different subject positions to balance devotion, artistry, legitimacy, and livelihood.
Coupling of N-tosylhydrazones with tetrazoles: synthesis of 2-β-d-glycopyranosylmethyl-5-substituted-2H-tetrazole type glycomimetics
Authors: Kaszás Tímea , Cservenyák Ivett , Juhász-Tóth Éva , Kulcsár Andrea E. , Granatino Paola , Nilsson Ulf J. , Somsák László , Tóth Marietta
Published: December 2020

The first tosylhydrazone-tetrazole coupling provides a straightforward access to a new type of glycomimetics with exclusive regioselectivity.
Low‐complexity detection for uplink massive MIMO SCMA systems
Authors: Sharma Sanjeev , Deka Kuntal , Beferull‐Lozano Baltasar
Published: December 2020

This paper presents a sparse code multiple access (SCMA) system with massive antennas at the base station. This system is referred to as M‐SCMA system. A spectrally‐efficient and massive access next‐generation wireless network is realized through massive antennas and non‐orthogonal SCMA techniques. Two detection algorithms, namely, modified message passing algorithm (MMPA) and extended message passing algorithm (EMPA) are proposed to detect multiple users' symbols in M‐SCMA. A deep learning (DL)‐based detection scheme is also proposed for M‐SCMA so as to avoid channel estimation and to lower the detection complexity. Numerical results show that the DL‐based detection has similar performance as MMPA even when the channel information is not estimated explicitly. Furthermore, authors also establish the sum rate trade‐off between SCMA and orthogonal multiple access in a massive antenna system. The impact of various M‐SCMA parameters such as the number of antennas and the overloading factor, on the proposed DL, MMPA, and EMPA‐based detection are also investigated.
Review of automated segmentation approaches for knee images
Authors: Ridhma  , Kaur Manvjeet , Sofat Sanjeev , Chouhan Devendra K.
Published: December 2020

Knee disorders are common among the human population. Knee osteoarthritis (OA) is the most widespread knee joint disorder, which may require surgical treatment. The detection and diagnosis of knee joint disorders from medical images demand enormous human effort and time. The development of a computer‐aided diagnosis (CAD) system can notably minimise the burden of medical experts and remove the intra‐observer and inter‐observer variations. To achieve the goal, the highly challenging research problem of knee image segmentation has been frequently paid attention in past years, which can be efficiently applied in the development of the CAD system. Knee image segmentation is a challenging task owing to the image contrasts, intensity variations, shape irregularities, and the presence of thin cartilage structures. Therefore, this paper presents a literature review of automated segmentation approaches mainly focused on the segmentation of knee cartilage and bone, with respect to the underlying technical aspects, datasets used, and the performance reported. The paper also presents the growth from classical segmentation approaches towards the deep learning approaches in the knee image segmentation. Owing to the varying quality and complexity of different knee image datasets, this paper abstains from doing a rigorous comparative evaluation of image segmentation approaches.
Spatiotemporal analysis of the land surface temperature distribution over the territory of Novosibirsk city based on Landsat data
Authors: Mamash Elena A. , Pestunov Igor A. , Chubarov Dmitri L.
Published: December 2020

The paper discusses the applicability of Landsat 8 data for analyzing the land surface temperature distribution over the territory of Novosibirsk. The satellite data is compared with the data from ground meteorological stations. Using cloud-based systems and methods for processing time series of satellite data, a composite image of the temperature ﬁeld for the territory of Novosibirsk is built; trends and anomalies in the temperature distribution in the urban area are studied. The results could be applied in urban development analysis and management of the city territory.
Use of navigation satellite signals to determine stocks of stem wood
Authors: Makarov Daniil , Borisov Aleksandr , Ostylovsky Anatoly , Ivanov Viktor , Kharlamov Dmitry
Published: December 2020

The method for determining the stocks of stem wood using the measurement data of the linear attenuation coefficients of signals navigation satellites L1 range and general taxometric characteristics of the forest is presented. A variant of determining the stocks of stem wood by differences in contributions to the attenuation by layers of crowns and trunks is considered, taking into account the coordinate referencing of the trajectory of the probe signal in the tree stand.
La transe dans le moment présent de la dispute de couple
Authors: Duriez Nathalie
Published: December 2020

Nous proposons d’envisager le moment présent de la dispute de couple comme un vécu de transe négative (Perlmutter & Sauer, 1986). La relation de couple est organisée à partir d’un mythe fondateur que les expériences douloureuses du passé et l’évolution des conjoints avec le temps peuvent remettre en question. Dans ce contexte d’insécurité, chez des sujets particulièrement réactifs, un mot peut alors déclencher une dispute qui plonge les sujets dans un état de transe négative. La répétition ou ritualisation de ces moments de transe entraînera l’extinction du mythe d’harmonie initial qui sera alors remplacé par des mythes de la discorde distincts pour chacun. Avec la perte du mythe commun, les conjoints perdent aussi la connexion qui les unissait et réécrivent alors leur histoire commune. Un extrait de l’entretien lors de la première séance de la thérapie du couple PaulEmma est analysé selon une approche phénoménologique. Nous retrouvons dans la narration de Paul et Emma des expériences d’induction, de transe et de fabrication de nouveaux mythes. L’attention clinique portée à ces niveaux d’expériences peut guider le thérapeute dans ses interventions pour aider le couple à retrouver sa fonction mythopoïétique et construire un nouveau mythe qu’ils pourront partager.
Gadolinium-based contrast agents: What we learned from acute adverse events, nephrogenic systemic fibrosis and brain retention
Authors: Bäuerle Tobias , Saake Marc , Uder Michael
Published: December 2020

Background Radiologists have been administering gadolinium-based contrast agents (GBCA) in magnetic resonance imaging for several decades, so that there is abundant experience with these agents regarding allergic-like reactions, nephrogenic systemic fibrosis (NSF) and gadolinium retention in the brain.

Methods This review is based on a selective literature search and reflects the current state of research on acute adverse effects of GBCA, NSF and brain retention of gadolinium.

Results Due to the frequent use of GBCA, data on adverse effects of these compounds are available in large collectives. Allergic-like reactions occurred rarely, whereas severe acute reactions were very rarely observed. Systemic changes in NSF also occur very rarely, although measures to avoid NSF resulted in a significantly reduced incidence of NSF. Due to gadolinium retention in the body after administration of linear MR contrast agents, only macrocyclic preparations are currently used with few exceptions. Clear clinical correlates of gadolinium retention in the brain could not be identified so far. Although the clinical added value of GBCA is undisputed, individual risks associated with the injection of GBCA should be identified and the use of non-contrast enhanced MR techniques should be considered. Alternative contrast agents such as iron oxide nanoparticles are not clinically approved, but are currently undergoing clinical trials.

Conclusion GBCA have a very good risk profile with a low rate of adverse effects or systemic manifestations such as NSF. Gadolinium retention in the brain can be minimized by the use of macrocyclic GBCA, although clear clinical correlates due to gadolinium retention in the brain following administration of linear GBCA could not be identified yet.

Key Points:

Citation Format
Gold Catalysis and Furans: A Powerful Match for Synthetic Connections
Authors: Nejrotti Stefano , Prandi Cristina
Published: December 2020

This review summarizes the advances made on the synthesis and functionalization of furans via gold catalysis during the period between 2016 and 2020. A separate section is dedicated to the tandem gold-catalyzed synthesis and functionalization of furans.

1 Introduction

2 Gold-Catalyzed Synthesis of Furans

2.1 Cycloisomerizations of Alkynyl and Cumulenyl Alcohols

2.2 Cycloisomerizations of Alkynyl and Allenyl Ketones

2.3 Reactions with External Oxidants

2.4 Miscellaneous

3 Gold-Catalyzed Functionalization of Furans

3.1 Cycloadditions

3.2 Furan Ring Decorations

3.3 Reactions Involving Furan Ring Opening

4 Gold-Catalyzed Tandem Synthesis and Functionalization of Furans­

4.1 Cycloisomerizations Followed by Gold-Catalyzed Cycloaddition

4.2 Cycloisomerizations to a Gold 1,3- or 1,4-Dipole and Intermolecular Annulation

4.3 Cycloisomerizations to a Gold Carbene and Intermolecular Trapping

5 Conclusion
Long-lived life history for onaga Etelis coruscans in the Hawaiian Islands
Authors: Andrews Allen H. , Brodziak Jon , DeMartini Edward E. , Cruz Eric
Published: December 2020

Onaga Etelis coruscans is an important component of the commercial deep-water handline fishery in Hawaii and is one of the more valuable species because of its local popularity. This species is part of a management unit called the Deep 7, a data-poor fishery comprising six snapper and one grouper species for which information about age, growth, longevity and maturity is incomplete. Although some life history information is available for onaga, prior estimates of maximum age (~10–20 years) likely suffered from underestimation of age, whereas two recent studies provided estimates that were similar to the work presented here—a refined age reading protocol revealed age estimates up to 55 years. This maximum age estimate and the age reading protocol used on onaga otoliths were validated using bomb radiocarbon dating. Using an otolith reference image age reading protocol that relied on the validated otolith sections, almost all onaga otoliths covering nearly the full body size range were used to generate valid growth parameters that may be sexually dimorphic. An empirical estimate of age at the length at which 50% of individuals reach maturity (L50) is 11 years, and fish near the minimum retention size in Hawaii (1 lb (~0.45kg) or ~30-cm fork length) may be just 2–3 years old.
Croton argenteus (silver July croton).
Authors: Rojas-Sandoval Julissa
Published: December 2020

C. argenteus is an herbaceous weed of open sunny sites, pastures, and agricultural lands. It is also a common weed in rice plantations (González, 2000). Because this species grows in seasonally waterlogged areas, its seeds are often dispersed as a contaminant in dried and wet mud (Standley and Steyermark, 1946). Currently, it is listed as invasive only in Cuba, but it is a common weed in dry and wet fields in areas within and outside its native distribution range (Oviedo Prieto et al., 2012; USDA-NRCS, 2015).
Caladium bicolor (heart of Jesus).
Authors: Rojas-Sandoval Julissa
Published: December 2020

C. bicolor is a dormant geophyte herb extensively commercialized in the horticultural trade around the world (Deng, 2012; USDA-ARS, 2016). It is often cultivated as an ornamental and potted plant and naturalized populations of C. bicolor can be found in areas within and outside its native distribution range (Madison, 1981; Govaerts, 2016). Currently, C. bicolor is listed as invasive in Trinidad and Tobago, Guam, Micronesia, Palau, Hawaii and the Philippines, where it is considered a species that is altering native plant communities by displacing native species, and changing community structures and ecological functions (Space et al., 2003; Herrera et al., 2010; PIER, 2016; Trinidad Biodiversity, 2016).
Least-squares Wavelet and Cross-wavelet Analyses of VLBI Baseline Length and Temperature Time Series: Fortaleza–Hartebeesthoek–Westford–Wettzell
Authors: Ghaderpour Ebrahim
Published: December 2020

Extensive least-squares wavelet and cross-wavelet analyses are performed on the Very Long Baseline Interferometry (VLBI) baseline length and temperature time series for a network of four VLBI antennas located in different continents. These analyses do not rely on any pre-processing of the measurements including interpolations or gap-filling, and they can provide accurate instantaneous frequency information along with phase differences in the time–frequency domain. Out of four antennas mounted in Fortaleza, Hartebeesthoek, Westford, and Wettzell, the most and the least possibly impacted VLBI time series by the annual temperature variation are Westford–Wettzell and Fortaleza–Hartebeesthoek, respectively. Furthermore, the annual components of the temperature time series in Westford and Wettzell lead the ones in the corresponding VLBI time series by nearly one month, where one of the baseline sides is either in Westford or Wettzell.
III International Seminar on Pedagogical Practice
Authors: Prada-Nuñez R , Hernández-Suárez C A , Dueñas Ramírez L M , Sandoval-Amador A , V-Niño E D
Published: December 2020

The pedagogical practices are the various actions that the teacher executes to enhance the human development of the student. Within these activities are teaching, communicating, socializing experiences, reflecting from everyday life, evaluating cognitive processes and even interacting with the educational community. These practices require a conceptual, procedural and strategie preparation on the part of the teacher. Their knowledge will never be enough to achieve that their students as individuals or collectively manage to appropriate the seeds of knowledge that they must acquire.

The riskiest teachers build their proposals for pedagogical practices within the framework of research projects, to obtain models that allow evaluating the effectiveness of their activities. Later, after an act of reflection and argumentation based on their own experiences as well as those of others, these innovative teachers manage to have sufficiënt arguments to socialize and disseminate their new knowledge and experience acquired.

List of titles Organizing Committee, International Scientific Committee, National Scientific Committee, Sponsor, Partners are available in this Pdf.
Geometry for design: approaches to the study of representation and dimension and their contributions to the modeling of phenomena
Authors: Acevedo-Rincon J P , Flórez-Pabón C E
Published: December 2020

The difficulties of representation and understanding of the dimension are evident in the different educational levels. University education is no stranger to this situation. This communication was developed within the framework of the graphic design course. This course was designed under the use of specialized software in geometry, which was freely available and intuitive. It should be remembered that the adequate use of representations and attributes proper to the dimension aids in the representations of movement phenomena, as well as in the representations in force diagrams in the teaching of physics. This qualitative research aims to address aspects of representation and dimensionality from the description of some selected tasks of the group participants, who contrast the first representations, with their final activities. That is, these representations showed their evolution in construction, to the extent that the flat representations of objects in the portfolio were built in real dimensions, keeping the proportional relationship between its parts.
Simulation of optimal exploitation of production wells in northern oil and gas fields
Authors: Filimonov M Yu , Vaganova N A
Published: December 2020

In this paper a new model of the propagation of thermal fields in frozen soil from production wells in the northern oil and gas fields is considered. The proposed model takes into account the most significant thermal insulation characteristics of wells, including the intertube space. The developed complex of programs and the performed numerical simulatons allow to significantly reduce the area of the projected well pads of the oil and gas field by reducing the predicted radius of thawing of frozen soil from functioning wells and choosing the optimal mode of the operation during 30 years.
Influence of metal nitrates on the process of coal oxidation of various metamorphism stages
Authors: Larionov K B , Zenkov A V , Mishakov I V , Gromov A A
Published: December 2020

The process of oxidation of lignite and bituminous coal modified with metal nitrates (Cu, Ce, Na, Co, Fe) in the amount of 5 wt.% is studied. Application of additives to the coal samples is carried out by the method of incipient wetness impregnation with preliminary dissolution of the additive in an aqueous-alcohol solution with a volume ratio of C2H5OH/H2O=50/50. Reactivity of the samples is studied by thermogravimetric analysis in the oxidation mode at a heating rate of 2.5 °C/min in the temperature range 25–600°C at atmospheric pressure. It has been found that application of activating additives contributes to reduction of the initial temperature of intensive oxidation (Ati=5–97°C) and to a shift of the process to the low-temperature region as a whole. According to the results obtained, the greatest activity is specific for addition of Cu(NO3)2. It is manifested in a decrease in the temperature of the beginning of intensive oxidation ti and an increase in the average reaction rate wav. The Coats-Redfern method is used to calculate activation energy of the oxidation process in the presence of activating additives. Maximum decrease in Eais observed for a copper nitrate-modified coal sample.
Uncertainty of the shadow method for the analysis of evaporating droplets
Authors: Antonevich Y V , Zaitsev D V , Kabov O A
Published: December 2020

The shadow method of image analysis is the most commonly used experimental technique for investigation of evaporating droplet dynamics and wettability. So, the shadow method uncertainty and limit of its applicability for analysis of evaporating droplets are actual issues. In this paper, we experimentally study the applicability limit of the shadow image analysis and contributions of errors, connected with non-telecentricity of the optical system, as well as diffraction and numerical errors, at various stages of droplet evaporation.
Three-dimensional simulation of drop motion in channels of different cross-sections
Authors: Solnyshkina O A , Fatkullina N B , Bulatova A Z
Published: December 2020

Three-dimensional Boundary Element Method accelerated using a heterogeneous Fast Multipole Method is employed to study two-phase flow in a microchannel of different cross-sections. The flow of a mixture of two Newtonian liquids with equal viscosities and densities is described by Stokes equations. A comparison of the simulation results of the droplet dynamics in cylindrical capillaries with experimental data available in the literature was carried out and showed the qualitative agreement. The deformable droplet motion is considered in a channel with a circle, square, and hexagon cross-sectional shape. The influence of droplet size on a relative velocity in a channel is studied. The applied approach to numerical simulation can be used to solve a wide range of problems related to emulsion flows in microscales.
Thermodynamic modeling of the gas-plasma phase in the processing of radioactive graphite in a gas plasma furnace
Authors: Barbin N M , Kobelev A M , Terent’ev D I
Published: December 2020

The method of thermodynamic modeling was used to determine composition and thermophysical properties of a gas-plasma phase of a system of radioactive graphite – water vapor in the temperature range from 1000 to 3200 K. It has been established that in the temperature range from 1000 to 1100 K, the main components of the gas-plasma phase are H2, CO, H2O, CO2, CH4. In the temperature range from 1100 to 2200 K – H2, CO, H2O, CO2. At temperatures from 2200 to 2600 K those are H2, CO, H2O, CO2, H. In the temperature range from 2600 to 3000 K those are H2, CO, H2O, CO2, H, OH. In the temperature range from 3000 to 3200 K those are H2, CO, H2O, H, CO2, OH, O, O2. The thermophysical properties of the system under consideration have been calculated: specific volume, entropy, enthalpy, total internal energy, number of moles in the system.
Magnetoplasmadynamic thruster with an applied field based on the second generation high-temperature superconductors
Authors: Voronov A.S. , Troitskiy A.A. , Egorov I.D. , Samoilenkov S.V. , Vavilov A.P.
Published: December 2020

The present work reports the results of the magnetoplasmadynamic (MPD) thruster with an applied field (AF) based on the second-generation high-temperature superconductor (2G HTS) tape functioning research. Achieved thrust, specific impulse, and efficiency were investigated. Experiments were performed on the 25-kW magnetoplasmadynamic thruster model with two types of 10-mm and 17-mm cathodes. The investigation tests were performed with the goal of studying the efficiency of using 2G HTS tape as electromagnetic coils creating applied field for MPD thruster. The used as the applied magnetic field for thruster 2G HTS coil creates magnetic field up to 1 Tesla. The results showed that the thrust and specific impulse with HTSC applied field increases up to 300% and efficiency increases up to 700%. The best achieved results are following: thrust up to 850 mN, specific impulse up to 3840 s, and efficiency up to 54%. Created MPD thruster with HTSC applied field has a resource of 5400 s work total with all the cathodes, more than 150 launches, and single continuous launch up to 140 seconds. The experiments performed show the high efficiency of using the 2G HTS tape as the material for the electromagnetic coils creating applied field for magnetoplasmadynamic thrusters. Strong applied field up to 1 T electromagnetic coils were maid of the 2G HTS tape by SuperOx own production facilities.
Modification of the singlet equation for a molecular system of solid spheres near a solid surface in the Percus-Yevick approximation
Authors: Agrafonov Yu V , Petrushin I S
Published: December 2020

An analysis of theoretical methods for studying the molecular structure of liquids bordering a solid surface was carried out. It was established that the currently existing nonlinear integral equations for partial distribution functions do not have an analytical solution for spatially inhomogeneous liquids. A linear integral equation having an analytical solution for a system of solid spheres near a solid surface was proposed.
Comparative investigation of Zr-Mo-Si-B thin films using picoindener module and nanohardness tester
Authors: Kiryukhantsev-Korneev Ph V , Loginov P A , Orekhov A S
Published: December 2020

Zr–Mo-Si-B coatings were successfully deposited using non-reactive magnetron sputtering of ceramic ZrMoSiB target. Structural investigations have been carried out using X-ray diffraction analysis, high-resolution transmission and scanning electron microscopy, glow-discharge optical-emission, and energy-dispersive spectroscopy. The coatings were subjected to the indentation using nanohardness-tester and picoindenter module placed in the column of transmission electron microscope. The obtained results show that the coatings consist of hcp-ZrB2 phase with needle crystallites 5-10 nm in diameter elongated in the direction of growth. The coatings demonstrated relatively high mechanical properties and recordable elastic recovery up to 84%. Results of indentation tests exhibited the close results.
The Study of Phase Equilibria and Superprotonic Crystals in the (NH4)2SO4 - K2SO4 - H2SO4 - H2O system
Authors: Komornikov V A , Timakov I S , Makarova I P , Selezneva E V , Grebenev V V , Zainullin O B
Published: December 2020

The phase equilibria in the quaternary water-salt system K2SO4 - (NH4)2SO4 - H2SO4 - H2O at a temperature of 35 °C were studied for the first time. The areas of crystallization, solubility, and reproducible conditions for obtaining crystals of solid solutions were determined: (Ki_
x
(NH4)
x
)2SO4, (Ki.
x
(NH4)
x
)3H(SO4)2, (Ki.
x
(NH4)
x
)9H7(SO4)8H2O, which are superprotonics. The study of phase equilibria in ternary systems K2SO4 - H2SO4 - H2O and (NH4)2SO4 - H2SO4- H2O was carried out, the solubility values and the solubility character of the compounds (NH4)2SO4 and K2SO4, (NH4)3H(SO4)2 and K3H(SO4)2, K9H7(SO4)8H2O, NH4HSO4 n KHSO4 were determined.
Axisymmetric plasma mode in disk with two-dimensional electron gas
Authors: Rodionov D A , Zagorodnev I V , Zabolotnykh A A , Volkov V A
Published: December 2020

A theory of resonant absorption in disk with two-dimensional electron gas has been developed when the wavelength of external radiation is comparable with the radius of the disk. We have analyzed analytically and numerically the position and the linewidth of the resonant peak, which corresponds to excitation of the axisymmetric (quadrupole) plasma mode in the disk. We have found dependence of the plasma resonance characteristics on a dimensionless retardation parameter that is equal to the product of the plasma frequency and the radius of the disk divided by the speed of light. We have shown that the linewidth is not merely the sum of collisional and radiation decay, but also contains “interference” terms.
Computer Algebra Methods in Modeling the Dynamics of Particle Beams in Accelerators
Authors: Andrianov Sergey
Published: December 2020

This article is devoted to the methods of numerical and symbolical methods of calculations, which are based on perturbation theory and are implemented in terms of matrix formalism. These methods were used to solve various problems of modeling and optimization in accelerator physics. The basic theoretical principles are verified using methods to neural network technologies, machine learning and others.
Shock wave and radiation at explosion of spherical HE charge inside a tube filled with xenon
Authors: Anderzhanov E K , Medvedev S P , Tereza A M , Khomik S V , Khristoforov B D
Published: December 2020

The operation of a powerful source of optical radiation based on explosion of spherical HE charges in metal tubes filled with xenon was investigated. The velocity and radiative characteristics of the shock wave propagating through the tube were determined. It is shown that reflective coating of pipe walls makes it possible to increase the density of the energy flux by more than an order of magnitude as well as to improve the shape of its time dependence. A three-dimensional numerical simulation of the formation and propagation of a shock wave was performed, and a simplified method for estimating the radiation intensity was proposed.
Molecular dynamics simulation of polymerization of the carbon under thermal decomposition of methane at constant volume
Authors: Kudinov A V , Gubin S A , Bogdanova Yu A
Published: December 2020

Thermal decomposition of methane was simulated at high temperature and pressure using the molecular dynamics method. The calculation was carried out employing ReaxFFlg potential. We show the dependence of the decomposition products on time and the results of methane polymerization at constant temperature. We also show the influence of gradual temperature decrease at the size of the polymers.
Electric probe measurements of chemical ionization behind reflected shock waves
Authors: Vlasov P A , Ryabikov O B , Smirnov V N , Mikhailov D I , Pankrat’eva I L , Polyanskii V A
Published: December 2020

Chemical ionization is the process of formation of charged particles as a result of energy release during the formation of chemical bonds in chemical reactions between neutral components. Chemical ionization is most often observed in the processes of hydrocarbon combustion. Measurements of ionization current in internal combustion engines are of great practical interest. Most experiments on chemical ionization were carried out in flames with obvious limitations: the composition of the mixture cannot be changed in an arbitrarily wide range of concentrations of fuel and oxidant, to investigate the pyrolysis processes, to arbitrarily change the temperature and pressure, it is impossible to dispose of the transfer processes and gradients of temperature and reactive components. Experiments in shock tubes in the reflected shock waves are free of all of the above disadvantages. In the present work, electric currents to the electrically insulated and uninsulated cylindrical probes were recorded, to which a negative (−9V) or positive (+9V) potentials were applied. In these experiments, the displacement and the total currents were recorded respectively. In the same experiments, the signals of chemiluminescent emission of electronically excited OH* radicals (λ = 308 nm) were simultaneously recorded. The main goal of the present work was to measure experimentally (1) the displacement currents on positive and negative probes, (2) the total and displacement currents on a negative cylindrical probe during acetylene pyrolysis and oxidation, and (3) to confirm correlation of the displacement currents and the signals of chemiluminescent emission of electronically excited OH* radicals.
First results and future prospects with PHELEX
Authors: Kopylov A , Orekhov I , Petukhov V
Published: December 2020

First results on the search for hidden-photon (HP) dark matter by multi-cathode counters are presented. The new experiment – PHELEX is described. The possibility to detect diurnal variations of the count rate from HPs in PHELEX experiment is discussed.