bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimizing one-dose and two-dose cholera vaccine allocation in outbreak settings: A modeling study
Authors: Leung Tiffany , Eaton Julia , Matrajt Laura
Published: April 2022

Background

A global stockpile of oral cholera vaccine (OCV) was established in 2013 for use in outbreak response and are licensed as two-dose regimens. Vaccine availability, however, remains limited. Previous studies have found that a single dose of OCV may provide substantial protection against cholera.

Methods

Using a mathematical model with two age groups paired with optimization algorithms, we determine the optimal vaccination strategy with one and two doses of vaccine to minimize cumulative overall infections, symptomatic infections, and deaths. We explore counterfactual vaccination scenarios in three distinct settings: Maela, the largest refugee camp in Thailand, with high in- and out-migration; N’Djamena, Chad, a densely populated region; and Haiti, where departments are connected by rivers and roads.

Results

Over the short term under limited vaccine supply, the optimal strategies for all objectives prioritize one dose to the older age group (over five years old), irrespective of setting and level of vaccination coverage. As more vaccine becomes available, it is optimal to administer a second dose for long-term protection. With enough vaccine to cover the whole population with one dose, the optimal strategies can avert up to 30% to 90% of deaths and 36% to 92% of symptomatic infections across the three settings over one year. The one-dose optimal strategies can avert 1.2 to 1.8 times as many cases and deaths compared to the standard two-dose strategy.

Conclusions

In an outbreak setting, speedy vaccination campaigns with a single dose of OCV is likely to avert more cases and deaths than a two-dose pro-rata campaign under a limited vaccine supply.
Academic medicine’s glass ceiling: Author’s gender in top three medical research journals impacts probability of future publication success
Authors: Krstacic John E. , Carr Brendan M. , Yaligar Ashutosh R. , Kuruvilla Annet S. , Helali Joshua S. , Saragossi Jamie , Zhu Chencan , Hutnik Robert , Noubani Mohammad , Yang Jie , Tannous Henry J. , Shroyer A. Laurie W.
Published: April 2022

Introduction

In December 2017, Lancet called for gender inequality investigations. Holding other factors constant, trends over time for significant author (i.e., first, second, last or any of these authors) publications were examined for the three highest-impact medical research journals (i.e., New England Journal of Medicine [NEJM], Journal of the American Medical Association [JAMA], and Lancet).

Materials and methods

Using randomly sampled 2002-2019 MEDLINE original publications (n = 1,080; 20/year/journal), significant author-based and publication-based characteristics were extracted. Gender assignment used internet-based biographies, pronouns, first names, and photographs. Adjusting for author-specific characteristics and multiple publications per author, generalized estimating equations tested for first, second, and last significant author gender disparities.

Results

Compared to 37.23% of 2002 – 2019 U.S. medical school full-time faculty that were women, women’s first author publication rates (26.82% overall, 15.83% NEJM, 29.38% Lancet, and 35.39% JAMA; all p < 0.0001) were lower. No improvements over time occurred in women first authorship rates. Women first authors had lower Web of Science citation counts and co-authors/collaborating author counts, less frequently held M.D. or multiple doctoral-level degrees, less commonly published clinical trials or cardiovascular-related projects, but more commonly were North American-based and studied North American-based patients (all p < 0.05). Women second and last authors were similarly underrepresented. Compared to men, women first authors had lower multiple publication rates in these top journals (p < 0.001). Same gender first/last authors resulted in higher multiple publication rates within these top three journals (p < 0.001).

Discussion

Since 2002, this authorship “gender disparity chasm” has been tolerated across all these top medical research journals. Despite Lancet’s 2017 call to arms, furthermore, the author-based gender disparities have not changed for these top medical research journals - even in recent times. Co-author gender alignment may reduce future gender inequities, but this promising strategy requires further investigation.
Changes in tree functional composition across topographic gradients and through time in a tropical montane forest
Authors: Báez Selene , Fadrique Belén , Feeley Kenneth , Homeier Jürgen
Published: April 2022

Understanding variation in tree functional traits along topographic gradients and through time provides insights into the processes that will shape community composition and determine ecosystem functioning. In montane environments, complex topography is known to affect forest structure and composition, yet its role in determining trait composition, indices on community climatic tolerances, and responses to changing environmental conditions has not been fully explored. This study investigates how functional trait composition (characterized as community-weighted moments) and community climatic indices vary for the tree community as a whole and for its separate demographic components (i.e., dying, surviving, recruiting trees) over eight years in a topographically complex tropical Andean forest in southern Ecuador. We identified a strong influence of topography on functional composition and on species’ climatic optima, such that communities at lower topographic positions were dominated by acquisitive species adapted to both warmer and wetter conditions compared to communities at upper topographic positions which were dominated by conservative cold adapted species, possibly due to differences in soil conditions and hydrology. Forest functional and climatic composition remained stable through time; and we found limited evidence for trait-based responses to environmental change among demographic groups. Our findings confirm that fine-scale environmental conditions are a critical factor structuring plant communities in tropical forests, and suggest that slow environmental warming and community-based processes may promote short-term community functional stability. This study highlights the need to explore how diverse aspects of community trait composition vary in tropical montane forests, and to further investigate thresholds of forest response to environmental change.
Relationship between lymphedema after breast cancer treatment and biophysical characteristics of the affected tissue
Authors: Perez Carla S. , Mestriner Carolina , Ribeiro Leticia T. N. , Grillo Felipe W. , Lemos Tenysson W. , Carneiro Antônio A. , Guirro Rinaldo Roberto de Jesus , Guirro Elaine C. O.
Published: April 2022

The treatment of breast cancer is often complicated by lymphedema of the upper limbs. Standard lymphedema evaluation methodologies are not able to measure tissue fibrosis. The ultrasound aspects related to tissue microstructures of lymphedema are neglected in clinical evaluations. The objective of this study was to identify and measure the degree of impairment, topography, and biophysical alterations of subcutaneous lymphedema tissue secondary to the treatment of breast cancer by ultrasonography. Forty-two women at a mean age of 58 (±9.7) years, with unilateral lymphedema due to breast cancer treatment, were evaluated. The upper limbs were divided into affected (affected by lymphedema) and control (contralateral limb). Each limb was subdivided into seven areas, defined by perimetry, evaluated in pairs. The biophysical characteristics thickness, entropy, and echogenicity were evaluated by ultrasonography. The results showed a significant difference in the echogenicity and thickness variables between the affected and unaffected upper limb, in all the extent of the upper limb, while entropy showed no significant difference. The findings indicate that the data presented were consistent both in identifying and measuring the degree of impairment and biophysical changes in the subcutaneous tissue of lymphedema secondary to the treatment of breast cancer.
Large-scale investigations of Neolithic settlement dynamics in Central Germany based on machine learning analysis: A case study from the Weiße Elster river catchment
Authors: Miera Jan Johannes , Schmidt Karsten , von Suchodoletz Hans , Ulrich Mathias , Werther Lukas , Zielhofer Christoph , Ettel Peter , Veit Ulrich
Published: April 2022

The paper investigates potentials and challenges during the interpretation of prehistoric settlement dynamics based on large archaeological datasets. Exemplarily, this is carried out using a database of 1365 Neolithic sites in the Weiße Elster river catchment in Central Germany located between the southernmost part of the Northern German Plain and the Central Uplands. The recorded sites are systematically pre-processed with regard to their chronology, functional interpretation and spatial delineation. The quality of the dataset is reviewed by analyzing site distributions with respect to field surveys and modern land use. The Random Forests machine learning algorithm is used to examine the impact of terrain covariates on the depth of sites and pottery preservation. Neolithic settlement dynamics are studied using Site Exploitation Territories, and site frequencies per century are used to compare the intensity of land use with adjacent landscapes. The results show that the main trends of the Neolithic settlement dynamics can be derived from the dataset. However, Random Forests analyses indicate poor pottery preservation in the Central Uplands and a superimposition of Neolithic sites in the southernmost part of the Northern German Plain. Throughout the Neolithic the margins between soils on loess and the Weiße Elster floodplain were continuously settled, whereas only Early and Late Neolithic land use also extended into the Central Uplands. These settlement patterns are reflected in the results of the Site Exploitation Territories analyses and explained with environmental economic factors. Similar with adjacent landscapes the Middle Neolithic site frequency is lower compared to earlier and later periods.
Art by firelight? Using experimental and digital techniques to explore Magdalenian engraved plaquette use at Montastruc (France)
Authors: Needham Andy , Wisher Izzy , Langley Andrew , Amy Matthew , Little Aimée
Published: April 2022

Palaeolithic stone plaquettes are a type of mobiliary art featuring engravings and recovered primarily from Magdalenian sites, where they can number from single finds to several thousand examples. Where context is available, they demonstrate complex traces of use, including surface refreshing, heating, and fragmentation. However, for plaquettes with limited or no archaeological context, research tends to gravitate toward their engraved surfaces. This paper focuses on 50 limestone plaquettes excavated by Peccadeau de l’Isle from Montastruc, a Magdalenian rockshelter site in southern France with limited archaeological context; a feature common to many art bearing sites excavated across the 19th and early 20th Centuries. Plaquette use at Montastruc was explored via a programme of microscopy, 3D modelling, colour enhancement using DStretch©, virtual reality (VR) modelling, and experimental archaeology, the latter focusing on limestone heating related to different functional and non-functional uses. While the limited archaeological context available ensures the results remain only indicative, the data generated suggests plaquettes from Montastruc were likely positioned in proximity to hearths during low ambient light conditions. The interaction of engraved stone and roving fire light made engraved forms appear dynamic and alive, suggesting this may have been important in their use. Human neurology is particularly attuned to interpreting shifting light and shadow as movement and identifying visually familiar forms in such varying light conditions through mechanisms such as pareidolic experience. This interpretation encourages a consideration of the possible conceptual connections between art made and experienced in similar circumstances, such as parietal art in dark cave environments. The toolset used to investigate the Montastruc assemblage may have application to other collections of plaquettes, particularly those with limited associated context.
Reduction in malaria burden following the introduction of indoor residual spraying in areas protected by long-lasting insecticidal nets in Western Kenya, 2016–2018
Authors: Dulacha Diba , Were Vincent , Oyugi Elvis , Kiptui Rebecca , Owiny Maurice , Boru Waqo , Gura Zeinab , Perry Robert T.
Published: April 2022

Background

Long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) are the main malaria vector control measures deployed in Kenya. Widespread pyrethroid resistance among the primary vectors in Western Kenya has necessitated the re-introduction of IRS using an organophosphate insecticide, pirimiphos-methyl (Actellic® 300CS), as a pyrethroid resistance management strategy. Evaluation of the effectiveness of the combined use of non-pyrethroid IRS and LLINs has yielded varied results. We aimed to evaluate the effect of non-pyrethroid IRS and LLINs on malaria indicators in a high malaria transmission area.

Methods

We reviewed records and tallied monthly aggregate of outpatient department (OPD) attendance, suspected malaria cases, those tested for malaria and those testing positive for malaria at two health facilities, one from Nyatike, an intervention sub-county, and one from Suba, a comparison sub-county, both located in Western Kenya, from February 1, 2016, through March 31, 2018. The first round of IRS was conducted in February–March 2017 in Nyatike sub-county and the second round one year later in both Nyatike and Suba sub-counties. The mass distribution of LLINs has been conducted in both locations. We performed descriptive analysis and estimated the effect of the interventions and temporal changes of malaria indicators using Poisson regression for a period before and after the first round of IRS.

Results

A higher reduction in the intervention area in total OPD, the proportion of OPD visits due to suspected malaria, testing positivity rate and annual malaria incidences were observed except for the total OPD visits among the under 5 children (59% decrease observed in the comparison area vs 33% decrease in the intervention area, net change -27%, P <0.001). The percentage decline in annual malaria incidence observed in the intervention area was more than twice the observed percentage decline in the comparison area across all the age groups. A marked decline in the monthly testing positivity rate (TPR) was noticed in the intervention area, while no major changes were observed in the comparison area. The monthly TPR reduced from 46% in February 2016 to 11% in February 2018, representing a 76% absolute decrease in TPR among all ages (RR = 0.24, 95% CI 0.12–0.46). In the comparison area, TPR was 16% in both February 2016 and February 2018 (RR = 1.0, 95% CI 0.52–2.09). A month-by-month comparison revealed lower TPR in Year 2 compared to Year 1 in the intervention area for most of the one year after the introduction of the IRS.

Conclusions

Our findings demonstrated a reduced malaria burden among populations protected by both non-pyrethroid IRS and LLINs implying a possible additional benefit afforded by the combined intervention in the malaria-endemic zone.
The effect of controlling person’s illegalities on stock price returns: Evidence from Elman neural network model
Authors: Xiao Ming , Guo Ying , Yang Xionghui , Li Ge , Kholaif Moustafa Mohamed Nazief Haggag Kotb
Published: April 2022

Controlling persons are the ultimate decision-makers of listed companies. Their illegalities have impacts on investors’ wealth, firm development, and capital market’s quality. Against this backdrop, we provide a quantitative analysis of the short-term stock price reaction to the criminal detention announcements of controlling persons throughout 2007–2019. We applied the Elman neural network (ENN) model into the classical event study methodology and demonstrated that the combination of them helps to improve the estimation accuracy of the stock price reaction. The results show that the stock price has a significant negative reaction to the criminal detention announcements of listed companies’ controlling persons on the announcement day, and the average reaction level is -6.67%. Additionally, the crisis communication measures of the firms could diminish the negative impact of such mandatory disclosure information on their stock price, but the effect is limited. Finally, the 31 companies in our sample cause a total loss of RMB 21.1 billion in market capitalization on the announcement day alone. The above results indicate that the impact of listed companies’ controlling persons on the capital market is tremendous, although the number of this group is small. Our work enriches the listed companies’ illegalities research and provides a reference for investors’ investment choices and follow-up decision making of regulatory authorities. It also provides some guidance for most of the researchers to further explore the application of data mining techniques in nonlinear problems.
Clinical significance and intestinal microbiota composition in immunocompromised children with norovirus gastroenteritis
Authors: Lin Pei-Chun , Yang Yu-Chen S. H. , Lin Sheng-Chieh , Lu Meng-Che , Tsai Yin-Tai , Lu Shou-Cheng , Chen Shu-Huey , Chen Shih-Yen
Published: April 2022

Background

Norovirus (NoV) infection is common in pediatric patients with immunodeficiency and is more likely to cause severe disease. Objective Our study aims to figure out the clinical differences and distribution of intestinal microbiota in immunocompromised children with NoV gastroenteritis.

Methods

Pediatric patients admitted to Shang-Ho Hospital with diagnosis of acute gastroenteritis including different immune status were enrolled and their medical records were reviewed. NoV gastroenteritis was validated using RT-PCR molecular methods. Viral shedding period was determined by real-time RT-PCR assays. Intestinal microbiota enrichment analysis was carried out by next generation sequencing after fecal DNA extraction and subsequent Linear Discriminant Analysis (LDA) Effect Size (LEfSe) method.

Results

Significantly higher frequency of diarrhea [mean, (IQR), 3.8 (3–5) /day] and longer viral shedding time [mean, IQR, 8.5 (5–13) days] was found in immunocompromised NoV infections than in immunocompetent patients without NoV infections (p = 0.013*) and immunocompetent patients with NoV infections (p = 0.030**). The fever prevalence was significantly lower in immunocompromised NoV infections than in different immune or infection status. Intestinal microbiota metagenomics analysis showed no significant community richness difference while the LEfSe analysis showed a significant difference in commensal richness at the phylum level, the family level, and the genus level in patients under different immune status.

Conclusion

We evaluated the clinical significances and microbiota composition in immunocompromised children with norovirus gastroenteritis. This will further facilitate studies of the interaction between the intestinal microbiota in such patients with precise determination of their bacterial infection control and probiotic supplements strategy.
COVID-19 distributes socially in China: A Bayesian spatial analysis
Authors: Peng Di , Qian Jian , Wei Luyi , Luo Caiying , Zhang Tao , Zhou Lijun , Liu Yuanyuan , Ma Yue , Yin Fei
Published: April 2022

Purpose

The ongoing coronavirus disease 2019 (COVID-19) epidemic increasingly threatens the public health security worldwide. We aimed to identify high-risk areas of COVID-19 and understand how socioeconomic factors are associated with the spatial distribution of COVID-19 in China, which may help other countries control the epidemic.

Methods

We analyzed the data of COVID-19 cases from 30 provinces in mainland China (outside of Hubei) from 16 January 2020 to 31 March 2020, considering the data of demographic, economic, health, and transportation factors. Global autocorrelation analysis and Bayesian spatial models were used to present the spatial pattern of COVID-19 and explore the relationship between COVID-19 risk and various factors.

Results

Global Moran’s I statistics of COVID-19 incidences was 0.31 (P<0.05). The areas with a high risk of COVID-19 were mainly located in the provinces around Hubei and the provinces with a high level of economic development. The relative risk of two socioeconomic factors, the per capita consumption expenditure of households and the proportion of the migrating population from Hubei, were 1.887 [95% confidence interval (CI): 1.469~2.399] and 1.099 (95% CI: 1.053~1.148), respectively. The two factors explained up to 78.2% out of 99.7% of structured spatial variations.

Conclusion

Our results suggested that COVID-19 risk was positively associated with the level of economic development and population movements. Blocking population movement and reducing local exposures are effective in preventing the local transmission of COVID-19.
Method for absolute quantification of short chain fatty acids via reverse phase chromatography mass spectrometry
Authors: Bihan Dominique G. , Rydzak Thomas , Wyss Madeleine , Pittman Keir , McCoy Kathy D. , Lewis Ian A.
Published: April 2022

Short chain fatty acids (SCFAs; including acetate, propionate, and butyrate) are an important class of biological molecules that play a major role in modulating host-microbiome interactions. Despite significant research into SCFA-mediated biological mechanisms, absolute quantification of these molecules in their native form by liquid chromatography mass spectrometry is challenging due to their relatively poor chromatographic properties. Herein, we introduce SQUAD, an isotope-based strategy for absolute quantification of SCFAs in complex biological samples. SQUAD uses aniline derivatization in conjunction with isotope dilution and analysis by reverse-phase liquid chromatography mass spectrometry. We show that SQUAD enables absolute quantification of biologically relevant SCFAs in complex biological samples with a lower limit of detection of 40 nM and a lower limit of quantification ranging from 160 nM to 310 nM. We observed an intra- and inter-day precision under 3% (relative standard deviation) and errors in intra- and inter-day accuracy under 10%. To demonstrate this quantification strategy, we analyzed SCFAs in the caecal contents of germ free versus conventionally raised specific pathogen free (SPF) mice. We showed that acetate was the most abundant SCFA in both types of mice and was present at 200-fold higher concentration in the SPF mice. We also illustrated the use of our quantification strategy inin vitromicrobial cultures from five different species of bacteria grown in Mueller Hinton media. This study illustrates the diverse SCFA production rates across microbial taxa with acetate production serving as one of the key differentiating factors across the species. In summary, we introduce an isotope dilution strategy for absolute quantification of aniline-dativized SCFAs and illustrate the utility of this approach for microbiome research.
Cognition, educational attainment and diabetes distress predict poor health literacy in diabetes: A cross-sectional analysis of the SHELLED study
Authors: Chen Pamela , Callisaya Michele , Wills Karen , Greenaway Timothy , Winzenberg Tania
Published: April 2022

Objectives

To identify factors that predict poor health literacy amongst people with diabetes.

Design

Cross-sectional analysis of baseline data from a prospective study of diabetic foot disease.

Setting

Patients attending a tertiary hospital diabetes outpatient clinic in Tasmania, Australia.

Participants

222 people with diabetes mellitus, aged >40 years, with no history of foot ulceration, psychotic disorders or dementia.

Outcome measures

Health literacy was measured using the short form Test of Functional Health Literacy in Adults (functional health literacy), and the Health Literacy Questionnaire (HLQ), which measures nine domains of health literacy. Predictors included demographic characteristics, cognition, diabetes distress, depression, and educational attainment.

Results

In multivariable analysis, greater educational attainment (OR 0.88, 95% CI 0.76, 0.99) and poorer cognition (OR 0.71, 95% CI 0.63, 0.79) were associated with poorer functional health literacy. Age was negatively associated with domains of appraisal of health information and ability to find good health information (both beta = -0.01). Educational attainment was positively associated with four domains, namely having sufficient information to manage my health, actively managing my health, appraisal of and ability to find good health information (beta ranging from +0.03 to 0.04). Diabetes distress was negatively associated with five domains: having sufficient information to manage my health, social support for health, ability to actively engage with healthcare providers, navigating the healthcare system and ability to find good health information (beta ranging from -0.14 to -0.18).

Conclusion

Poorer cognition and poorer educational attainment may be detrimental for an individual’s functional health literacy, and education, diabetes distress and older age detrimental across multiple health literacy domains. Clinicians and policy makers should be attuned to these factors when communicating with people with diabetes and in designing healthcare systems to be more health-literacy friendly in order to improve diabetes outcomes.
Domestic tethers: Gender differences in career paths and domestic responsibilities of top-research medical school graduates
Authors: Hitti Eveline , Hadid Dima , Khoury Samia J. , Tamim Hani , Makki Maha , Karam Charlotte M.
Published: April 2022

Introduction

Gendered differences in career paths of medical graduates persist globally. We aim to explore the impact of domestic tethers on the career paths of physicians by studying gendered differences in domestic burdens of physicians as well as differences in perceptions around the impact of domestic work on professional advancement.

Methods

A web-based survey including 38 questions was sent to all 3866 physician alumni of the top academic medical school in Lebanon. Data was collected between November 2018 and January 2019, with up to three invite reminders. Overall, 382 were included in the final analysis, 124 women (32%), 258 men (68%).

Results

The study had a response rate of 10.4%. Findings show that a greater percentage of men were married and had children (77.5% vs 62.1%, p = 0.004, 77.9% vs 51.6%, <0.001, respectively). Majority of both women and men held full-time positions (82.1% and 87.1%), having children however reduced the odds significantly [OR = 0.2, 95% CI: (0.1–0.6), p = 0.01]for women, while only older age reduced it for men (OR = 0.1,95% CI: (0.04–0.2), p<0.001]. Among full-time physicians, men and women spent similar time on professional activities (60.2hrs/wk vs 58.3hrs/wk, p = 0.32). Women spent more time on parenting and household work (23.5hrs/wk vs 10.4hrs/wk, <0.001; 8.9hrs/wk vs 6.0hrs/wk, p = 0.001, respectively). Women physicians’ spouses contributed to 14.5 hours/week of total time on domestic activities whereas men physicians’ spouses spent two folds more time on domestic activities (35.0 hours/week, P<0.001). Of physicians with children, a higher percentage of women than men reported that children prevented their career advancement or their participation in development opportunities (43.8% vs 15.9%, p<0.001; 50.0% vs 19.4%, p<0.001, respectively). A greater percentage of women than men scaled back their career after first child (31.3% vs 3.5%, <0.001). Of married/partnered physicians, fewer women than men reported their career took priority over their partner’s when conflicts arose, (52.0% vs 86.0%, p<0.001).

Conclusion

These findings highlight the heavier impact of domestic tethers on the career paths of women physicians than men physicians. Men are more likely than women to hold full-time positions in the early advancement defining phases of their careers. Full-time women shoulder more domestic work than men and experience more professional advancement concessions. Closing persistent gender gaps in medicine requires addressing inequities in domestic burdens through strategies that include mentorship on domestic tethers, support of on-site child-care and advocacy for parental leave policies that encourage shared care-work.
What We Know about Human Traffickers in Vietnam
Authors: Luong Le , Wyndham Caitlin
Published: April 2022

Myths and misconceptions about traffickers, the nature of trafficking, and how the crime varies in different jurisdictions pose challenges for prevention work, rehabilitating offenders, and achieving justice for victims. This article, based on an analysis of over 100 human trafficking court cases in Vietnam, outlines the reality of one particular trafficking crime: the trafficking of Vietnamese women and girls for sexual exploitation in China. We show that the majority of the prosecuted traffickers are similarly poor and vulnerable as their victims. Most are from ethnic minorities, with a poor educational background, and few income generation opportunities. Based on this evidence, we discuss some challenges associated with prosecution of these particular traffickers and suggest more effective approaches for human trafficking prevention.
Sex Traffickers: Friend or foe?
Authors: Hamid Haezreena
Published: April 2022

This article addresses the knowledge gap surrounding human traffickers in Malaysia. Based on qualitative interviews with women identified as victims of trafficking, it explores the women’s perception of their traffickers and their migration experience. The article asserts that the term ‘trafficker’ is complex and misunderstood by scholars, states, and state officials; and that trafficked persons may not necessarily detest their traffickers or even regard them as having caused them harm. Instead, traffickers are sometimes considered ‘helpers’ or people who provide work opportunities and a prospect of a better life. However, this form of relationship is considered exploitative by Malaysian legislation.
Ensino de Robótica Móvel através da Realização de um Hackathon em ROS
Authors: Junior Alexandre de Oliveira , Assumpção Heitor Dutra de , Queiroz Jonas , Piadi Luis , Leitão Paulo , Pérez-Pons María-Eugenia , Prieto Javier , Parra-Domínguez Javier
Published: April 2022

robótica móvel é um campo que vem crescendo constante- mente nos últimos anos, possuindo aplicações em diversas áreas como a indústria, agricultura, medicina, entre outros. Sendo o ROS uma das principais platafor- mas de desenvolvimento de softwares desta área e visando a disseminação do conhecimento destas tecnologias, foi proposto um hackathon para fomentar a aprendizagem em ROS e robótica móvel. A decisão por essa abordagem foi de- vido à dificuldade de novos usuários no primeiro contato com a plataforma, por possuir conceitos complexos e ausência de front-end, o primeiro contato com ROS é difícil, levando os novos usuários a desistência. Com isso, o ensino foi fei- to por meio deste evento - que é uma atividade imersiva e intensa para a solução de problemas na instância tecnólogica, principalmente em programação. De forma, que as primeiras barreiras fossem quebradas, o processo de aprendizagem facilitado e estimulasse os participantes a seguirem essa linha de pesquisa. O público alvo são estudantes de engenharia eletrotécnica, computação, mecânica e entusiastas em robótica. Neste paper será apresentada a estruturação do Hac- kathon, que compreende um nivelamento dos estudantes, para capacitá-los a programar as funcionalidades essenciais de um robô móvel e, por fim, o desafio robótico proposto. As etapas iniciais foram elaboradas com dificuldades que au- mentaram progressivamente, iniciando com tarefas de controlo básico de um robô simulado até o desafio de desenvolver uma navegação autónoma em um ambiente de simulação buscando uma fonte de gás cuja posição é desconhecida.
Effect of Carboxymethyl Cellulose Concentration on Structural, Morphological and Magnetic Properties of Barium Hexaferrite: A Study Based on Sol-Gel Auto-Combustion Method
Authors: Rattanaburi Parintip , Porrawatkul Paweena , Teppaya Nongyao , Noypha Amnuay , Pimsen Rungnapa , Chanthai Saksit , Nuengmatcha Prawit
Published: April 2022

This study was intended to assess the role of carboxymethyl cellulose (CMC) as a chelating agent in
the synthesis of barium hexaferrite (BaFe12O19:BaF). The effect of varying concentrations of CMC
was studied via the sol-gel auto-combustion method following the requirements of green chemistry
synthesis. The formation of BaF nanoparticles was confirmed using XRD, SEM, EDS, VSM, FTIR
and UV-Vis-DRS techniques. The characterized XRD peak indicates the formation of good quality
crystalline samples at 6% (w/v) of CMC concentration. SEM analysis suggested that the synthesized
BaF is spherical, with sizes ranging from 10-15 nm. The M-H hysteresis loops obtained for the samples
showed their soft and hard magnetic behaviour. With the increasing CMC concentration, magnetism
becoming harder and an increase in the Ms value can be observed. The UV-Vis-DRS techniques revealed
that the band gap energy of synthesized BaF increased with an increase in the concentration of CMC.
Review on Plant Mediated Green Synthesis of Magnetite Nanoparticles for
Pollution Abatement, Biomedical and Electronic Applications
Authors: Mangamma J. Laxmi , Rama Devi Dharamasoth , Vidya Sagar P.S.R. , Babu M. Ramesh , Basavaiah Keloth
Published: April 2022

In nature, the iron oxide is found in various forms. It is chemically mixed to form iron oxides
(compounds). Magnetite has helpful uses in different areas, such as medicinal carriers, MRI-contracting
agents, tumour therapies, industrial, laboratory dyes adsorption and wastewater treatment of toxic
metals such as mercury and arsenic. Magnetic iron oxide nanoparticles are generated using various
methods such as wet, dry or microbiological processes. The drawbacks of conventional nanoparticles
including attrition and pyrolysis include a defective surface formation, poor efficiency rates, high
development costs and high energy consumption. The first approach is the green biosynthesis of the
nanoparticles in which the metal atoms are clusters. The organic compounds can both minimize and
cover nanoparticles in the process of synthesis in green materials. In recent years, nanocarriers, especially
for poorly soluble medicines, have received growing attention for oral chemotherapy. Early disease
bacteria, biopsy, cells, DNA, glucose and viruses are identified by biosensing. While several basic
characteristics have different advantages and potential for biomedical use of magnets of iron oxides,
more toxicological research is required on as-synthesized magnet iron oxide nanoparticles with clearly
defined requirements for toxicity assessment.
Adherence and growth outcomes in children with growth disorders: results from the Easypod™ Connect Observational Study (ECOS) in Indonesia, Singapore, and Taiwan
Authors: Pulungan Aman Bhakti , Yap Fabian , Chao Mei-Chyn , Loke Kah Yin , Yang Chen , Ma Tianrong , Ovbude Leroy , Su Pen-Hua
Published: April 2022

Background Non-objective assessments indicate poor patient adherence to growth hormone (GH) prescribed for growth failure, with sub-optimal growth response. The easypod™ connect device for GH administration enables real-time, objective assessment of adherence.

Objective To examine adherence with pediatric GH therapy in Asia-Pacific countries and relationship with growth outcomes.

Methods Subjects were children in Indonesia, Singapore, Taiwan enrolled in the multi-national, open-label Easypod Connect Observational Study (ECOS). Adherence during follow-up was the primary endpoint and a relationship with 1-year growth outcomes was assessed by Spearman’s product-moment correlations.

Results Over a 1-year time frame, median overall patient adherence was ≥89%; rates were similar for children with GH deficiency (GHD; n=17) and those born small-for-gestational age (SGA; n=5), except that median adherence dropped between 9 months (94%) and 1 year (83%) for SGA subjects. Median initial GH dose was 42.3µg/kg/day for GHD subjects and 31.4µg/kg/day for SGA subjects. Median age (12 years) and bone age (13 years) indicated that most children had entered puberty at treatment onset. Clinically meaningful improvements in growth were observed at 1 year in the GHD group, but not the SGA group. Statistically significant correlations between adherence and height change (P=0.039) as well as height velocity (P=0.004) were observed.

Conclusions Children in Asia-Pacific countries show high adherence over the first year of GH therapy with easypod. The easypod study also shows that adherence is correlated to good growth outcomes.
Vitamin D, insulin-like growth factor-1, and stunting in children with transfusion-dependent thalassemia
Authors: Pratiwi I Gusti Ayu Putu Eka , Irawan Roedi , Ugrasena I Dewa Gede , Faizi Muhammad
Published: April 2022

Background Transfusion-dependent thalassemia (TDT) has a major impact on a child’s growth and is associated with stunting, risk of vitamin D deficiency, and decreased insulin-like growth factor-1 (IGF-1). To date, the relationship between vitamin D levels and stunting in TDT remains unclear. Futhermore, the role of vitamin D and IGF-1 in mediating stunting in TDT patients is still unknown. 

Objective To investigate the relationship between stunting and vitamin D as well as IGF-1 levels in children with TDT.

Methods This cross-sectional study involved 50 TDT children aged 5 to 18 years, included consecutively from the Pediatric Hemato-oncology Outpatient Clinic, Dr. Soetomo Hospital, Surabaya, East Java. Subjects were divided into two groups: stunted (S) and not stunted (NS). Vitamin D and IGF-1 were evaluated by antibody competitive immunoassay and sandwich-enzyme-linked immunosorbent assay (ELISA), respectively. Age, sex, and duration of repeated transfusion were analyzed as confounding factors.

Results Median IGF-1 levels were 91.43 (13.67-192.86) ng/mL and 161.53 (17.99-363.01) ng/mL in the S and NS groups, respectively (P=0.011). Mean vitamin D levels were 20 (+ 5.71) ng/mL and 20.46 (5.25) ng/mL in the S and NS groups, respectively (P=0.765). The correlation coefficient (r) of vitamin D and IGF-I levels was not significant. Multivariate analysis showed that low IGF-1 levels, male, and longer duration of repeated transfusions were associated with stunting in children with TDT. 

Conclusion Low IGF-1 level is associated with stunting in children with TDT. Vitamin D is not significantly associated with either stunting or IGF-1 in children with TDT.
Insight into Management Issues modeling for Perfect Business Simulation
Authors: Shaikh Sadique , Kankariya Rajkumar
Published: April 2022

In this paper, I try to focus on widely growing field of Management Science; and that, “Modeling of Management Issues “. Now days Business Simulation techniques are used to earn more profit from Business and this is only issues control future course of actions properly. By using models we can predict & control future course of action & situation. Modeling is not a new subject. It’s oldest technique, but widely used in Physical Sciences, like Chemistry, Physics, Electronics, Engineering field, But it’s again become vital after some time in Life Sciences, like Botany, Zoology, Bio-Chemistry, Bio-Tech and Medical field problem modeling and now in current world it’s also become very vital in Information Technology and Management subjects. Here one question is always arise, why such a modeling is needed, and where and when needed, and answer of this simple question is, considering some simple problems like ‘ to find out the width of a river (But your are not allowed to cross it), find out the temperature (but you are not allowed to use thermometer), means try to find out any Quantity or parameter/variable without existence or entity of that, and if virtual situation satisfied by using modeling technique, we implement that virtual model for actual situation. In last I want to conclude modeling is the heart of any branch of Education, weather its science, Arts, Commerce, Medical, Information Technology, Engineering or Management and in summaries form I want to say this paper is nothing but one of the theoretical model, which is for modeling of Management issues for perfect Business Simulation.
A modular extension of a finite element contact implementation
Authors: Faltus Ondřej , Horák Martin
Published: April 2022

The structural mechanics module of the OOFEM finite element software has been developed to include various algorithms for solving contact mechanics problems. After developing small strain contact algorithms in the 2D domain and their extension to large strain applications [1, 2], the present contribution extends the existing framework to the 3D domain. After reviewing the current code and comparing existing solutions found in the literature, we identify the common ground between 2D and 3D applications, then propose and implement the necessary changes and additions to smoothly integrate the 3D support into existing code. Tests and example problems are presented to confirm the functionality of the resulting implementation.
The effect of sampling volume size on the apparent stiffness of jointed rock mass
Authors: Lebeda Martin , Kabele Petr
Published: April 2022

Overall mechanical properties of a jointed rock mass are strongly affected by discontinuities – fractures – that naturally occur in rocks. Stochastically-generated discrete fracture network (DFN) modeling, which uses a probabilistic approach to describe the spatial distribution of fractures, such as position, size, or orientation, offers an explicit way to describe geometry of the fracture system. Many in-situ measurements and analyses presented in literature indicate that fractures’ sizes can be adequately represented by the power law probability distribution. The parallel plate model of individual fractures combined with an averaging technique makes it possible to estimate the overall compliance or stiffness of jointed rock mass (Oda et al. [1]). In the present study, a series of numerical simulations of jointed rock mass modeled by DFN and Oda’s approach were conducted to analyze the effect of different sizes of the sampling volume on the overall elastic moduli. The results of the numerical study show that the variance as well as the average of the apparent stiffness decrease as the size of sampling element grows.
Environmental perspectives of fine grounded concrete powder: LCA case study of light-weight concrete block
Authors: Pešta Jan , Prošek Zdeněk
Published: April 2022

The construction elements produced with low demand for primary resources are being developed in the building industry. However, not only consumption of primary resources but also environmental impacts of such products should be considered to increase the sustainability of the construction industry. To investigate the environmental impacts of lightweight concrete blocks, life cycle assessment (LCA) was used as an analytical tool according to the EN 15 804 + A2. Firstly, the properties of fine grounded concrete powder (FRWC) were measured to declare functionality and potential to use of the considered product. Then, the lightweight concrete block containing FRWC was designed. The potential environmental impacts of the lightweight concrete block were assessed for the following phases: raw material production, transport of materials, production of concrete block, and end of life of the block. The considered system boundaries includes the production of fine grounded concrete powder, which was produced by recycling demolished concrete structures. The results were related to 1 tun of lightweight concrete block. Unsurprisingly, the calculated impact is mainly influenced by cement production. The total impact of the life cycle of 1 t of the lightweight block is 336 kg CO2 eq. On the other hand, the lightweight block reached better results in the comparison with the Aerated Autoclaved Concrete block in most of the categories.
Sulphate corrosion of cement pastes with a high content of waste marble powder
Authors: Prošek Zdeněk , Tesárek Pavel
Published: April 2022

The article focuses on sulphate corrosion of cement pastes with a high content of waste micronized marble powder. Micronized marble powder is used as a substitute for Portland cement CEM I 42.5R. The amount of micronized marble powder used is from 5 to 50 wt. %. The research also tested a reference mixture composed only of Portland cement. The used accelerated sulphate corrosion consists of cyclic saturation and drying with 10% Na2SO4 solution for 56 days. During sulphate corrosion, samples are placed in a controlled environment at 5 ± 1 ◦C and 85 % relative humidity to allow thaumasite to form. During cycling, samples were continuously visually monitored and documented. Subsequently, after 56 days, the samples were destructively tested for compressive strength. The research revealed a negative effect of micronized marble powder on the resistance to sulphate corrosion, where in contrast to the reference mixture the decrease in compressive strength is up to twofold.
Finite element simulation of shear and compact tension tests on timber
Authors: Šmídová Eliška , Kabele Petr
Published: April 2022

The non-linear finite element simulation of the ASTM shear and pre-stressed compact tension tests was conducted. Tested specimens were cut from the glued laminated timber made of European spruce (Picea abies) with the lamina thickness of 10.5 mm and 45 mm. The 2D homogeneous orthotropic constitutive model of the tensile-shear fracture in timber, which has been proposed by the authors, was used. The model calibration was adopted from the authors’ recent experimental study. The numerical results show that the model can adequately reproduce both the experimental response and the crack pattern, which in certain cases comprises of cracking parallel or perpendicular to fibers. Furthermore, the results confirm that the value of the parameter fASTMxy , obtained from ASTM shear test as the maximum attained force divided by the shearing area, represents the averaged stress at the failure plane, while the extreme stress experienced by the material is much higher.
Influence of microstructure on rate-dependent response of unidirectional fibrous composites
Authors: Valentová Soňa , Šejnoha Michal , Vorel Jan , Prošek Zdeněk
Published: April 2022

This paper outlines prediction of the macroscopic response of unidirectional fibrous composites made either from basalt or carbon fibers impregnated by a polymeric epoxy matrix. The viscoelastic response of the matrix phase was represented by the Maxwell chain model. A series of creep tests performed at several stress levels served as a stepping stone for the model calibration. The macroscopic behavior of both composites was first examined via computational homogenization. Attention was accorded to computational cells with variable size extracted from large representative images. We observed that selecting the computational model as a sufficiently large test window should be approached with caution. Because initial designs often need a large parametric study to test various material and geometrical patterns, this study was then supported by computationally much more effective Mori-Tanaka averaging scheme, clearly showing its potential even if loading the composite beyond its elastic limit.