bluuebunny/crossref_metadata_2025 huggingface dataset:
High Burden of Self-Reported Sexually Transmitted Infections among Key Populations in Mozambique: The Urgent Need for an Integrated STI Surveillance System
Authors: Boothe Makini A.S. , Comé Charlotte , Baltazar Cynthia Semá , Chicuecue Noela , Seleme Jessica , Langa Denise Chitsondzo , Sathane Isabel , Raymond Henry Fisher , Fazito Erika , Temmerman Marleen , Luchters Stanley
Published: May 2020

Background: Key populations - men who have sex with men (MSM), female sex workers (FSW) and people who inject drugs (PWID) – are at high risk for STI infection given their sexual risk behaviours along with social, legal and structural barriers to prevention, care and treatment services. The purpose of this secondary analysis is to assess the prevalence of self-reported STIs among participations of the first Biological Behavioural Surveillance (BBS) in Mozambique and to describe associated risk factors.Methods: Responses from the first BBS surveys conducted in 2011-2014 were aggregated across survey-cities to produce pooled estimates for each population. Aggregate RDS-weighted estimates were computed to analyse self-reported STI prevalence. Unweighted pooled estimates were used in multivariable logistic regression to identify associated risk factors. Results: The prevalence of self-reported STI was 11.9% (95% CI: 7.8-16.0), 33.6% (95% CI: 29.0-41.3), and 22.0% (95% CI: 17.0-27.0) among MSM, FSW and PWID, respectively. MSM who were circumcised, had HIV, reported drug use, reported receptive anal sex, and non-condom use with their last male partner had greater odds of STI self-report. STI-self report among FSW was associated with living in Beira, being married, employment aside from sex work, physical violence, sexual violence, drug use, access to comprehensive HIV prevention services, non-condom use with last client, and sexual relationship with a non-client romantic partner. Among PWID, risk factors for self-reported STI infection included living in Nampula, access to HIV prevention services, and sex work.Conclusion: The high-burden of STIs among survey participants requires integrated HIV and STI prevention, treatment, and harm reduction services that address overlapping risk behaviours, especially injection drug use and sex work. A robust public health response requires the creation of a national STI surveillance system for better screening and diagnostic procedures within these vulnerable populations.
HIV-1 Infection Among Women in Israel, 2010-2018
Authors: Wagner Tali , Olshtain-Pops Karen , Wax Marina , Horwitz Olivia , Shirazi Rachel , Gozlan Yael , Volnowitz Hadar , Mendelson Ella , Levy Itzchak , Mor Orna
Published: May 2020

Introduction: Women comprise 33% of the HIV-1-carriers in Israel. However, women were not previously considered as a risk group needing special attention. Immigration waves from countries in Africa and in East Europe may have changed the local landscape of women diagnosed with HIV-1. Here we aimed to assess viral and demographic characteristics of women identified in Israel between 2010 and 2018. Methods: All > 16 years, HIV-1-infected women, diagnosed in Israel in 2010–2018, (n = 763) were included. Demographic and clinical characteristics were recorded. Viral subtypes and transmitted drug resistance mutations (TDRM) from 337 (44.2%), randomly selected, treatment-naive women, were analyzed using chi-square, logistic and segmented regression tests. Results: Median age at diagnosis was 38 years. Most (73.3%) were immigrants from former Soviet Union (FSU) (41.2%, 314) or sub-Saharan Africa (SSA) (32.2%, 246) and carried subtype A (79.7%) or C (90.3%), respectively. Only 11.4% (87) were Israeli-born women. Over the years, the prevalence of women from SSA decreased while that of women from FSU increased significantly (p < 0.001). Overall median CD4 counts was 263 cells/mm3, higher (391 cells/mm3) in Israeli born women. 10.4% had TDRM; 1.8%, 3% and 7.1% had protease inhibitors (PI), nucleotide reverse transcriptase inhibitors (NRTI) and non-nucleoside reverse transcriptase inhibitors (NNRTI) TDRM, respectively. Prevalence of women with NNRTI TDRM significantly increased from 4.9% in 2010–2012 to 13.3% in 2016–2018. Israeli-born women had the highest prevalence (16.3%) of NNRTI TDRM (p = 0.014). The NRTI A62 (5.6%), NNRTI E138 and K103 (5.6% and 4.2%, respectively) were the most prominent mutated sites. Conclusions: Most HIV positive women diagnosed in Israel in 2010–2018 are immigrants. Prevalence of those from FSU increases in recent years. The high proportion of women diagnosed with resistance mutations, particularly, the yearly increase in the frequency of NNRTI mutations, support the national policy of resistance testing at baseline.
Emergency and Urgent Dental Visits Among Medicaid Enrollees from 2013 to 2017
Authors: Fiehn Rebekah , Okunev Ilya , Bayham Mary , Barefoot Steven , Tranby Eric P
Published: May 2020

Background: Efforts to combat the spread of COVID-19 have led to guidance to restrict dental practice to treating emergency and urgent dental visits and reduce or eliminate elective dental procedures. Better understanding of the frequency of dental emergencies and the procedures performed during those emergency visits can help providers, insurers, and policymakers understand workforce and care provision needs.Methods: Procedures performed at an emergency dental encounter and in the encounter following that encounter are assessed. Emergency dental encounters are those with a CDT code of D0140, D0160, or D0170. Data was analyzed from the IBM Watson Medicaid Marketscan data from 2013 to 2017, a nationally representative dental and medical claims database from 13 deidentified states.Result: Consistently over time, about 10% of all dental encounters are due to a dental emergency. 28% of emergency dental encounters had no other procedure performed during those encounters. When other procedures were performed during the encounter, the majority were diagnostic in nature, primarily radiographs. Among patients who returned to the dentists following an emergency visit, 43% returned for more definitive dental treatment, most within 30 days. Among patients who returned to the dentists following an emergency visit, 43% returned for more definitive dental treatment, with the majority returning within 30 days for that treatment.Conclusions: The majority of dental emergency encounters do not result in definitive treatment, rather patients often return to the dentist at a later date for that treatment. Where possible, dental providers could utilize teledental services to triage patients to appropriate care.
Impact of Patron Saint Festivities on Cholera in Three Communes in Haiti
Authors: Moise Kenny , Batumbo Doudou , Achille Mélody Aude , Bourdeau Bertiny , Rebaudet Stanislas , Lerebours Gérald , Henrys Jean Hugues , Raccurt Christian
Published: May 2020

Introduction Religious pilgrimages are among the anthropogenic factors known to be associated with the transmission of diarrheal diseases, such as cholera. This ecological study aimed to describe the epidemiology of cholera in three communes in Haiti (Cabaret, Carrefour and Croix-des- Bouquets) in 2017 and assess the spatiotemporal influence of patron saint festivities on cholera incidence in communal sections.Materials/Methods An epidemiological curve was produced to illustrate the evolution of cholera at the communal level. Generalized linear models assuming a Poisson distribution were used to weight the annual cholera incidence of communal sections against variables such as the number of patronal festivities, population density and annual precipitation rates. The number of cases in the week of the festivity as well as one and two weeks later was weighted against patronal festivities and weekly precipitation rates.Results In total, 3 633 suspected cholera cases were continuously reported in three communes in Haiti (Cabaret, Carrefour, Croix-des-bouquets) during the 52-epidemiological week period in 2017. After controlling for rainfall and population density at the communal sections, the patronal festivities significantly reduced the annual incidence of cholera by 57.23%. The probability of occurrence of cholera cases one week after patronal festivities decreased by 25.41%.Conclusion This study showed a continuous presence of cholera in three communes in Haiti in 2017 and an association between the occurrence of patronal festivities in communal sections and a reduced probability of subsequent outbreaks. Although further assessments are necessary, these findings suggest an impactful prevention and response strategy around the festivities in 2017.
Structure and trends of international sport nutrition research between 2000-2018: bibliometric mapping of sport nutrition science
Authors: Kiss Anna , Temesi Ágoston , Tompa Orsolya , Lakner Zoltán , Soós Sándor
Published: May 2020

Background : The tool kits of bibliometrics and science mapping provide a standard methodology to map the knowledge base of specific fields of science. The aim of the present research is the analysis of the recent international trends of sport nutrition science, as well as the primary identification of the research topics and results of sport nutrition science via enhanced bibliometric methods for the 2000-2018 time period. Methods: Altogether, 3889 publications were included in this study. We identified the most relevant sport nutrition topics by running a community detection algorithm on the proximity network constructed via bibliographic coupling. The key issues and key concepts of sport nutrition topics as well as their relations were evaluated via network analysis. We also carried a chronological analysis of topics out, and a scientometric evaluative analysis was also created. Results: We identified the four main basic groups from which the 18 most characteristics topics were analyzed. The 18 topics are the following: Football and physiology; Carbohydrate metabolism; Muscle physiology: Alkalosis and Acidosis; Muscle power enhancement and dietary supplementation; Fluid balance and hydration; Dietary intake and nutrition knowledge; Assessment of Energy Intake of athletes; Bone health, Female Athlete Triad; Fluid intake strategy; Weight management; Nutritional Strategies and human skeletal muscle; Dietary nitrate supplementation; Oxidative stress and dietary supplement use; Dietary supplement use and doping; Oxidative stress, inflammation and dietary antioxidants; Training adaptation and nutritional strategies; Gut Microbiota; Celiac disease. Based on the size of the topic, research on sport nutrition science has put the biggest emphasis on the following three groups: Muscle power enhancement and dietary supplementation; Carbohydrate metabolism; and Oxidative stress and dietary supplement use. The greatest scientific impact can be ascribed to the following topics: Nutritional strategies and human skeletal muscle; Dietary nitrate supplementation; Weight management; and Gut microbiota. Conclusions: Scientific output on sport nutrition has continuously been rising between 2000-2018. The ratio of topics related to sport nutrition but first of all connected to basic research has decreased significantly within all publications. The results of this study confirm the role of science mapping in the identification of specific research topics and primary research directions in the field of sport nutrition science.
The mitochondrial K-ATP channel opener diazoxide upregulates STIM1 and Orai1 via ROS and the MAPK pathway in adult rat cardiomyocytes
Authors: Gavali Joice Thomas , Carrillo Elba Dolores , Garcia Maria Carmen , Sanchez Jorge Alberto
Published: May 2020

Background: Openers of mitochondrial adenosine triphosphate-dependent potassium (mKATP) channels like diazoxide increase reactive oxygen species (ROS) production in cardiac cells and reduce Ca2+ elevations produced by ischemia-reperfusion protecting the heart from damage. In this study we tested the hypothesis that opening mKATP channels regulates expression of the major components of store-operated Ca2+ entry (SOCE) STIM1 and Orai1. Methods: Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and western blot techniques were used to assess mRNA expression and protein abundance of STIM1 and Orai1. Confocal immunofluorescence imaging was used to visualize the distribution and localization of STIM1 and Orai1 and translocation of transcription factors NFkB and c-Fos into the nucleus.Results: Diazoxide increased expression of STIM1 and Orai1 at the mRNA and protein levels, respectively, in adult rat cardiomyocytes. Diazoxide also disrupted the striated distribution pattern of STIM1. These effects were prevented by the ROS scavenger N-acetyl cysteine (NAC), the mKATP channel antagonist 5-hydroxydecanoate (5-HD), or the protein synthesis inhibitor cycloheximide (CHX). Diazoxide also led to nuclear translocation of the transcription factors c-Fos and NFkB, which was also blocked by NAC or 5-HD. Finally, the MAPK pathway inhibitor UO126 attenuated diazoxide-induced upregulation of STIM1 and Orai1 expression Conclusions: Our results suggest that opening mitochondrial potassium ATP channels with diazoxide upregulates the expression of STIM1 and Orai1 by de novo synthesis by a mechanism that involves NFkB, c-Fos, and ROS via MAPK/ERK signaling.
How U.S. Public Universities Responded to the COVID-19 Pandemic in March 2020: Lessons Learned from the Variations in Timing of Key Decisions
Authors: Cevasco Kevin E. , North Hayley M. , Zeitoun Sheryne A. , Gregory Abigail F. , Wofford Rachel N. , Hassan Maha H. , Matulis Graham A. , Abdo Aya D. , Roess Amira A. , Farris David , Fricken Michael E von
Published: May 2020

The timing of the pandemic response decision can affect the national mass migration of millions of students back to campus thus limiting community spread. During the initial stages of the COVID-19 pandemic, universities across the United States were faced with making difficult decisions often without explicit or uniform guidance from state and national leadership. This study examines how and when public universities responded to the U.S. COVID-19 outbreak, regarding decisions to cancel international travel, switch to online learning, transition faculty and staff to remote work, limiting on-campus housing, and implementing campus closures. Data was collected on university timing and decision making for medium to large public universities with more than 5,000 enrolled students, representing 412 institutions, 7M people, and all 50 states and Puerto Rico, between February 27 and March 31st, 2020. Substantial heterogeneity in decision making and the timing of those decisions as they relate to key state, national, and global emergency announcements were observed. The WHO pandemic declaration coincided with announcements to move away from on-campus learning. Universities decisions were made largely at the university level and not coordinated by government agencies, leading to staggered announcements and major variations in university timelines between states and within states. The importance of synchronizing university decisions in a national emergency scenario cannot be understated. Dissonant university decisions and announcement dates may potentially lead to mixed messaging and a reduction of the effectiveness of early interventions. Clear guidance is needed moving forward regarding university operations for fall and summer.
Prevalence and associated factors of sarcopenia in Singaporean adults – the Yishun Study
Authors: Pang Benedict Wei Jun , Wee Shiou Liang , Lau Lay Khoon , Jabbar Khalid Abdul , Seah Wei Ting , Ng Daniella Hui Min , Tan Queenie Lin Ling , Chen Kenneth Kexun , Jagadish Mallya Ullal , Ng Tze Pin
Published: May 2020

Objectives: To describe the normative values of sarcopenia among community-dwelling adults (≥21), compare the prevalence of sarcopenia using AWGS2014, AWGS2019 and EWGSOP2 guidelines, and identify factors associated with sarcopenia.Design: Participants were recruited through random sampling. Sarcopenia assessments were performed using a DXA scan (muscle mass), handgrip test (muscle strength) and usual walking test (physical performance). Questionnaires were administered to evaluate lifestyle and cognition.Setting and Participants: 542 community-dwelling Singaporeans were recruited (21-90 years old, 57.9% women). Methods: We assessed anthropometry, body composition, and questionnaire-based physical and cognitive factors, and estimated sarcopenia prevalence according to the AWGS2014, AWGS2019 and EWGSOP2 recommendations, and examined associations using logistic regression.Results: According to AWGS2019, the Singapore population-adjusted sarcopenia prevalence was 13.6% (men 13.0%; women 14.2%) overall, and 32.2% (men 33.7%, women 30.9%) in those aged 60 and above. The cut-offs derived from young adult reference group for low ALMI is 5.28 kg/m2 for men and 3.69 kg/m2 for women (lower than AWGS recommended cut-off); for GS it is 0.82 m/s, (AWGS2019 recommended cut-off 1.0m/s, AWGS2014 cut-off was 0.8 m/s); for HGS, it is 27.9 kg /m2 for men, and 16.7 kg/m2 for women (close to AWGS2019 recommendation). Age, gender, marital status, alcoholism, physical activity, BMI, waist circumference and global cognition were associated with sarcopenia (p<.05).Conclusions and Implications: This is the first study to provide reference values of muscle mass, strength and gait speed across the adult lifespan of Singaporeans. Using AWGS2019 criteria, sarcopenia is prominent in older age (32.2% in ≥60 years old); but it is already non-trivial (6.9%) among young and middle-aged persons. Multi-domain lifestyle modifications addressing muscle strength, cognition and nutrition over the adult lifespan is important to delay the development of sarcopenia.
Analysis of the role of Chest X-Ray in a large cohort of 1117 patients with SARS-CoV-2 infection: an Italian multicenter study﻿
Authors: Vespro Valentina , Andrisani Maria Carmela , Fusco Stefano , Meglio Letizia Di , Plensich Guido , Scarabelli Alice , Stellato Elvira , Ierardi Annamaria , Scudeller Luigia , Coppola Andrea , Gori Andrea , Pesenti Antonio , Grasselli Giacomo , Aliberti Stefano , Blasi Francesco , Villa Chiara , Ippolito Sonia , Pirrò Barbara , Damiani Guglielmo , Galli Massimo , Rizzardini Giuliano , Catena Emanuele , Orlandi Matteo Agostino , Magnani Sandro , Cipolla Giuseppe , Ianiello Andrea Antonio , Petrillo Mario , Xhepa Genti , Cazzulani Alberto , Carrafiello Gianpaolo
Published: May 2020

Objective. To describe the radiographic key patterns on CXR in patients with SARS-CoV-2 infection, assessing the prevalence of radiographic signs of interstitial pneumonia. To evaluate pattern variation between a baseline and a follow-up CXR.Materials and methods. 1117 patients tested positive for SARS-CoV-2 infection were retrospectively enrolled from four centers in Lombardy region. All patients underwent a CXR at presentation. Follow-up CXR was performed when clinically indicated.Two radiologists in each center reviewed CXR images and classified them as suggestive or not for interstitial pneumonia, recording the presence of ground-glass opacity (GGO), reticular pattern or consolidation and their distribution.Pearson’s chi-square test for categorical variables and McNemar test (chi-square for paired data) were performed.Results. Patients mean age 63.3 years, 767 were males (65.5%). The main result is the large proportion of positive CXR in COVID-19 patients.Baseline CXR was positive in 940 patients (80.3%), with significant differences in age and sex distribution between patients with positive and negative CXR. 382 patients underwent a follow-up CXR. The most frequent pattern on baseline CXR was the GGO (66.1%), on follow-up was consolidation (53.4%). The most common distributions were peripheral and middle-lower lung zone.Conclusions. We described key-patterns and their distribution on CXR in a large cohort of COVID-19 patients: GGO was the most frequent finding on baseline CXR, while we found an increase in the proportion of lung consolidation on follow-up CXR. CXR proved to be a reliable tool in our cohort obtaining positive results in 80.3% of the baseline cases.
Gut metagenomics discriminates unique microbial signatures in diverse symptomatic profiles with attention-deficit/hyperactivity disorder
Authors: Li Yan , Sun Haiting , Huang Yufen , Yin Anqi , Wang Ping , Han Jiao , Qu Dingding , Zhuo Lixia , Tian Mei , Wang Chen , Jian Fangfang , Zhao Jinyang , Sun Silong , Rohde Luis Augusto , Xie Xuefeng , Sun Xin , Xiong Lize
Published: May 2020

BackgroundAttention-deficit/hyperactivity disorder (ADHD) is a highly heterogeneous psychiatric disorder that can be divided into inattentive (I-ADHD), hyperactive-impulsive (HI-ADHD), and combined (C-ADHD) subtypes. Different early life events and environmental factors correlated with the gut microbiota community have been implicated in the development of ADHD. However, whether different ADHD symptomatic presentations are associated with distinct microbiota composition and function still unknown. Therefore, we carried out metagenomic analysis from 207 subjects to characterize the gut microbial profiles in ADHD and subgroup patients.ResultsThe current study revealed that the gut microbiota composition (beta diversity) can be effectively distinguished between C-ADHD patients and HCs, but not I-ADHD patients and HCs, nor general ADHD patients and HCs. Features include underrepresentation of 8 species belonging to the genus Bacteroides and enrichment of 5 species of Bifidobacterium and Prevotella in general ADHD patients (all p < 0.05). Eight of the above species became progressively reduced (ovatus, thetaiotaomicron, intestinalis, cellulosilyticus, and fluxus belonging to the genus Bacteroides) or enriched (Prevotella_copri, Prevotella_buccae and Bifidobacterium_breve) from healthy controls (HCs) to I-ADHD and C-ADHD patients. Predicted metabolic functions from these distinguished gut microbial markers described a certain compensatory host metabolism in ADHD and subgroup patients. Particularly, pyridoxal 5'-phosphate (a dominant vitamin B6 active type) biosynthesis pathways were significantly reduced in C-ADHD patients, because serum vitamin B6 deficiency in ADHD patients was found previously. Of note, we identified diverse virulence factor and antibiotic resistance from the gut microbiota of ADHD patients. The abundance of antibiotic resistance ontology ANT(9)-Ia positively correlated with the abundance of Prevotella_amnii, which was enriched in ADHD patients. Moreover, species-based bacterial markers were used to construct classifiers and achieved a higher AUC of 0.87 in C-ADHD vs. HC than that in ADHD vs. HC (AUC = 0.84).ConclusionsThese findings uncover alterations in microbial composition in subgroup patients and provide potential biomarkers for diagnosis different symptomatic presentations for ADHD.Trial registration: ClinicalTrials.gov, NCT03447223. Registered 27 February 2018, https://clinicaltrials.gov/ct2/show/NCT03447223?term=03447223&draw=2&rank=1
Comparison between wild and related cultivated rice species reveals strong impacts of crop domestication on methane metabolism of the rhizomicrobiome
Authors: Tian Lei , Chang Jingjing , Shi Shaohua , Ji Li , Zhang Jianfeng , Li Xiujun , Veen Johannes A van , Kuramae Eiko E , Tian Chunjie
Published: May 2020

Background

Rice root-inhabited microbial communities are seriously affected by domestication as evidenced by comparing the rhizomicrobiomes of wild and related cultivated rice species. While earlier studies focused on the structures of the rhizomicrobiomes, here, we compared the functioning of the microbial communities in the rhizosphere of wild versus that of related cultivated rice species, which were originated from Africa and Asia.
Results

The microbial functions involved in carbon metabolism and nucleotide metabolism were found to be enriched in wild rice species, whereas those involved in nitrogen metabolism, lipid metabolism, metabolism of cofactors and vitamins, and xenobiotic biodegradation were more enriched in cultivated rice species. Among the overall carbon metabolism, specifically, methane metabolism of the rhizomicrobiomes clearly differed between wild and cultivated rice. The key enzymes in methane production and utilization were overrepresented in wild rice species, suggesting that the rhizomicrobiome of wild rice maintained a better ecological balance for methane production and utilization than the related cultivated rice species.
Conclusions

For the first time, the impacts of rice domestication on the main metabolic pathways of the rhizomicrobiome were assessed, which revealed the strong impacts of rice domestication on methane metabolism that is one of the most critical functions of the microbial community of the rhizosphere of rice. The results provide important guidelines for future breeding and cultivation of rice in the framework of more sustainable rice production.
Changing trends of birth weight with maternal age: a cross-sectional study in Xi'an city of Northwestern China
Authors: Wang Shanshan , Yang Liren , Shang Li , Yang Wenfang , Qi Cuifang , Huang Liyan , Xie Guilan , Wang Ruiqi , Chung Mei Chun
Published: May 2020

Background

Most studies have shown that maternal age was associated with birth weight. However, specific relationships between each additional year of maternal age and birth weight remain unclear. The study aimed to analyze the specific association between maternal age at birth and birth weight.

Methods

Raw data for all live births from 2015 to 2018 was obtained from the Medical Birth Registry of Xi’an, China. 490143 mother-child pairs with full-term singleton live birth and the maternal age ranged from 20 to 40 years old were included in our study. Birth weight, gestational age, the birth date of the newborns, maternal birth date, residence, and ethnicity were collected. Generalized additive model and two-piece wise linear regression model were used to analyze the specific relationship between maternal age and birth weight, risk of low birth weight, and risk of macrosomia.

Results

The relationships between maternal age and birth weight, risk of low birth weight, and risk of macrosomia were nonlinear. Birth weight increased 16.204 g per year before age 24(95%CI: 14.323, 18.086), and increased 12.051g per year when maternal age ranged from 24 to 34(95%CI: 11.609, 12.493), then decreased 0.824g per year (95% CI: -3.112, 1.464). The risk of low birth weight decreased until age 36(OR= 0.917, 95%CI: 0.903, 0.932 for maternal age younger than 27; OR= 0.965, 95%CI: 0.955, 0.976 for maternal age ranged from 27 to 36), then increased (OR= 1.133, 95%CI: 1.026, 1.250). The risk of macrosomia increased with the increase of maternal age (OR=1.102, 95%CI: 1.075, 1.129 for maternal age younger than 24; OR=1.065, 95%CI: 1.060, 1.071 for maternal age ranged from 24 to 33; OR= 1.029, 95%CI: 1.012, 1.046 for maternal age older than 33).

Conclusions

For women of childbearing age (20-40 years old), the threshold maternal age for low birth weight was 36 years old, and the risk of macrosomia increased with the increase of maternal age.
IMPROVING THE RELIABILITY OF THE HYDRAULIC PART OF THE OILFIELD PUMP, TAKING INTO ACCOUNT THE SELECTION OF MATERIAL FOR THE SEAL ASSEMBLY
Authors: Habibov Ibrahim Abulfaz , Huseynova Vusala Shakir , Abasova Sevinj Malik
Published: May 2020

Many years of experience in the operation of oilfield equipment during underground well repair shows that ensuring the reliability and durability of the pumping units used is one of the main elements of the process chain, largely determined by the quality and performance characteristics of the friction units of the hydraulic parts of the pumps.

It is known that high-pressure oilfield pumps used in the repair of oil and gas wells carry out various technological works, including cementing, hydraulic fracturing, acid treatment, washing sand plugs and other washing and squeezing operations.

Parts of the hydraulic parts of the pumps are subjected to abrasive, corrosion-mechanical and corrosion-abrasive wear, which often leads to sudden failures, fraught with emergencies, additional costs and loss of time for unscheduled repairs.

The article considers the possibility of increasing the reliability of plunger oilfield pumps due to the correct removal of the material of the sealing collars and improving the assembly scheme. It is also proposed to use the diffusion monotonic distribution as a model of failure to evaluate the reliability function of the selected best compression scheme. Since this distribution model is a more flexible function that better aligns qualified data, compared to the well-known two-parameter strict probability models.

The results of the work have theoretical and practical prerequisites for assessing the reliability of field pumping units and may be useful for specialists working in this field
OSMANLI İMPARATORLUĞU’NDA DEFTERDARLIK VE GÜNÜMÜZ YANSIMALARI
Authors: MERT Alican
Published: May 2020

Çalışma kapsamında Osmanlı İmparatorluğu’nun tarihte eşine az rastlanan uzunluktaki devlet yönetiminde büyük bir önemi olan defterdarlık makamı incelenmiştir. Günümüzdeki maliye bakanlığına benzetilebilecek olan bu makam, devletlerin siyasi varlıklarını sürdürebilmesi için zorunlu olan finans kaynaklarının kaydını ve kontrolünü yapmaktaydı. Osmanlı İmparatorluğu’nun uzun yıllar hüküm sürmesinde askeri başarılarının yanında, mali konulardaki yönetimsel başarısının etkisi yadsınamaz. Bu yönetimin yapıldğı makam ise defterdarlık olmuştur. Ancak bununla beraber defterdarlık, bürokrasi içinde büyük çekişmelere de sebep olmuş bir makamdır. Bu öneme haiz bir makamın kurumsal yapısının incelenmesi, Osmanlı mali yapısının ve bu makamın günümüz mali kurumlarına etkilerini anlamak bakımından gereklidir. İki bölümden oluşan bu çalışmada ilk bölüm olarak defterdarlığın kökeni, Osmanlı Devleti’nde ortaya çıkışı, görevleri, defterdar olarak seçilecek kişilerin taşıması gereken özellikler anahatları ile açıklanmış; ikinci bölümde ise defterdarlık makamının yönetim anlayışındaki ve devlet toprağının sınırlarındaki değişime bağlı olarak geçirdiği yapısal değişimler üzerinde durulmuştur. Osmanlı İmparatorluğu’nda makamın ilk ortaya çıkışından, maliye nezareti adını aldığı tarihe kadar olan süreç ele alınmıştır. Bu çalışma ile ise Osmanlı İmparatorluğu’nun mali alandaki temel kurumunun yapısal ve teknik özellikleri ortaya konulmak amaçlanmıştır.
El Derecho y el hombre
Authors: Lazo Arrasco Jorge
Published: May 2020

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El capitalismo popular, un tema de debate
Authors: Garcia Daniel
Published: May 2020

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Government assistance to state-owned enterprises: a hindrance to financial performance
Authors: Marimuthu Ferina
Published: May 2020

This study aimed to examine whether government financial assistance influences the financial performance of state-owned enterprises. Commercial state-owned enterprises in South Africa that are listed under the Public Financial Management Act during the post-apartheid era from 1995 to 2017 were sampled. Government guarantees were measured as a dummy variable, while financial performance was measured by accounting measure: return on assets (ROA). Endogeneity issues were addressed, and data analysis was performed on an unbalanced panel using the two-step system GMM. The empirical evidence indicated that support by the government in the form of guarantees and subsidies has a significant negative effect on the financial performance of state-owned enterprises. This is an indication that continued government bailouts to poor performing state-owned enterprises exacerbates their poor financial performance and encourages these enterprises to become too reliant on government assistance, burdening the national fiscus.
AcknowledgmentsThe author gratefully acknowledges the National Research Foundation of South Africa for the research grant and Dr Farai Kwenda for his supervision during the study.
Modeling and predicting earnings per share via regression tree approaches in banking sector: Middle East and North African countries case
Authors: A. H. Elamir Elsayed
Published: May 2020

The regression tree approach is an effective and easy to interpret technique where it utilizes a recursive binary partitioning algorithm that divides the sample into partitioning variables with the strongest correlation to the response variable. Earnings per share can be considered as one of the main factors in making the investment decision. This study aims to build a predictive model for earnings per share in the context of the Middle East and North African countries (MENA) . The sample of the study consists of sixty-three banks, which were chosen from eight countries, with a total of six-hundred thirty observations. The simple regression, regression tree, and its pruned regression tree, conditional inference tree, and cubist regression are used to build the predictive model for earnings per share that depends on total assets, total liability, bank book value, stock volatility, age of the bank, and net cash. The results show that the cubist regression is outperforming other approaches where it improves root mean square error for the predictive model by approximately double in comparison with other methods. More interesting results are obtained from the important scores, where it shows that the total assets of the bank, bank book value, and total liability have the biggest impact on the prediction of earnings per share. Also, the cubist regression gives an improvement in R-squared over other methods by at least 30% and 23% using training and testing data, respectively.
O ESTUDO EVOLUTIVO DO TREINAMENTO DO XADREZ E A INSERÇÃO DAS TECNOLOGIAS
Authors: Tirado Augusto Cláudio Santa Brígida , Brusamolin Valério
Published: May 2020

A introdução das tecnologias no jogo de xadrez promove transformações no treinamento dos enxadristas, a incorporação de novas metodologias de treinamento, revisão de conceitos clássicos e no aparecimento de um jogador tecnológico. Propõe-se observar como os enxadristas utilizam as novas tecnologias e a evolução a partir dos métodos tradicionais de treinamento. Por meio de estudo bibliográfico e com uso de metodologia qualitativa, procedeu-se à observação dos sistemas adotados pelos jogadores de competição, com ênfase em Grandes Mestres de xadrez. O artigo identificou uma nova abordagem no treinamento competitivo dos jogadores em parceria com os principais programas de xadrez que são utilizados. A utilização dos recursos tecnológicos, limitam-se ao estudo preparatório dos jogadores para as competições. Desta forma, o enxadrista necessita reunir habilidades diante do enfrentamento de seus adversários. A utilização priorizando a tecnologia, indica a valorização da memória sobre outros aspectos das capacidades do enxadristas. Entretanto, para a compreensão do jogo faz-se necessário o estudo dos métodos clássicos sob a luz das novas tecnologias. Desta forma o jogador adquire um melhor entendimento da mecânica do jogo e suas características.
XADREZ TERAPÊUTICO
Authors: Andrade Leo Pasqualini de , Silva Vander Pereira da
Published: May 2020

O jogo de xadrez, além de esporte e lazer, é um instrumento auxiliar para o desenvolvimento cognitivo e terapêutico. Nas escolas, a utilização do jogo de xadrez contribui para que crianças possam interagir e aprender de forma lúdica outras disciplinas, dentre elas a matemática. Como instrumento terapêutico, o jogo de xadrez chegou a hospitais psiquiátricos, consultórios psicopedagógicos e psicológicos, com resultados satisfatórios para pacientes, tais como, dependentes químicos, autistas, portadores de esquizofrenia, transtorno de déficit de atenção e hiperatividade, dislexia, entre outros. Professores de xadrez tem formado grupos de idosos que buscam no jogo uma alternativa prazerosa de exercitar o raciocínio. A literatura a respeito do xadrez terapêutico tem crescido nos últimos anos, porém ainda é pouco conhecida dos profissionais que lidam com as atividades de estimulação cognitiva. O objetivo deste artigo é levantar e relatar casos em que o jogo de xadrez serve como instrumento de estimulação cognitiva e terapêutica, com o intuito de contribuir com a divulgação para profissionais da saúde sobre uma nova abordagem de reabilitação. Esta nova abordagem de utilização do jogo de xadrez expressa uma visão da sociedade que busca alternativas aos tratamentos tradicionais, inclusive, como prevenção de doenças neurodegenerativas, em virtude do envelhecimento crescente da população, desejosa em preservar suas habilidades cognitivas, além de criar novas possibilidades de interação social.
STORYTELLING EM A RAINHA DE KATWE
Authors: De França Geovana Ezequieli , Rodriguez Paulo Virgilio Rios , Brusamolin Valério
Published: May 2020

As histórias e narrativas estão em todas as partes, compartilhar e contar acontecimentos faz parte do meio de socialização do homem, desde muito tempo. Por meio dessas histórias pode-se aprender algo novo, conhecer novos hábitos e costumes, se emocionar, se motivar e criar novos vínculos. Assim como a contação de histórias remete à socialização, jogar xadrez pode proporcionar o conhecimento de mundo, interesse pela escola, viagens, perspectiva de vida e esperança. O filme,“Rainha de Katwe”, conta a história de, Phiona Mutesi, uma jovem de uma região periférica da Uganda que, em pouco tempo, se torna campeã nacional de xadrez. O objetivo da pesquisa é identificar qual a influência do jogo de xadrez ao longo da história de vida da famosa Phiona Mutesi. Para entender compreender como os atores envolvidos nesse enredo utilizou-se da metodologia para a análise de discurso, desta forma é possível identificar os elementos presentes na narrativa do filme. Os resultados obtidos pelo estudo são importantes tanto para a área do xadrez como para as áreas de estudo que analisam a storytelling como uma ferramenta.
Vibration damping of the anti-vibration platform intended for use in combination with audio/music devices
Authors: Breńkacz Łukasz , Bagiński Paweł , Korbicz Jarosław K.
Published: May 2020

The article presents research on the damping properties of an anti-vibration platform (designed and manufactured by Stacore), which is intended for use in combination with high class audio devices. The platform comprises two parts that are capable of passive vibration damping. The design of this platform is unique and has been developed by applying several technical solutions in a combination not found on any other anti-vibration platform on the audio market. These solutions are described in the article. The first part of the platform is pneumatically operated and the second part uses ball bearings. The casing also fulfils the most important function – vibration damping. It is made of amorphous slate (known for its good vibration-damping properties) and includes a metal plate covered with a special visco-elastic layer that fulfils the role of binding material. The first part of the platform realises the pneumatic damping. It comprises four elastomer pneumatic springs, each with its own air tank. The air tanks are designed to operate at a maximum pressure of 5 bar. The second vibration-damping part of the platform is located above the first part (pneumatic) and consists of ball bearings, used for the isolation of transverse vibration, being relatively difficult to deal with pneumatic springs. The upper part consists of three bearings, each of which comprises of a polished, deep hardened steel racings and a ball made of tungsten carbide. The scientific literature describes many solutions enabling vibration damping, including many anti-vibration platforms. However, the literature lacks the descriptions of analyses conducted on anti-vibration platforms for audio devices. This article is a novelty in the literature as it concerns the experimental research aimed at verifying the vibration-damping capacity of the anti-vibration platform that can be used with audio devices owned by people who appreciate high-quality music. The article describes in detail the whole measurement procedure applied to the vibration damping platform. For research purposes, the anti-vibration platform was suspended on flexible ropes. At first, an electromagnetic vibration exciter was attached to the base on which the platform rested, and then the displacements of the upper and lower part of the platform were measured using laser sensors. Based on these signals, the vibration damping capability (transmissibility) of the platform was determined in two mutually perpendicular directions. In addition to the graph that shows the vibration damping capability of the anti-vibration platform, the signals of the applied force and displacements measured during the research are also presented in this article.
Turunçgil Posalarının Ruminant Beslemede Alternatif Yem Kaynağı Olarak Kullanımı ve Metan Üretim Kapasiteleri
Authors: BAŞAR Yunus , ATALAY Ali İhsan
Published: May 2020

Hatay ilinde yetişen turunçgil posalarının ruminant beslemede alternatif yem kaynağı olarak kullanımı ve metan üretim kapasitesini belirlemek amacıyla; kuru madde (KM), pH, olması gereken pH (OlpH), fleig skoru (FS), ham kül (HK), ham protein (HP), ham yağ (HY), ADF, NDF, net gaz, net metan gazı, metabolik enerji (ME) ve organik madde sindirim derecesi (OMSD) içerikleri belirlenmiştir. Araştırma sonunda pH değerleri 2.72 ile 3.48 arasında bulunan turunçgil silajının düşük değerlere sahip olması nedeniyle uzun süre depolanabilir bir silaj türü olduğu söylenebilir. Turunçgil silajları metan gazı üretim kapasitesi açısından değerlendirildiğinde % 8.17 ile 11.23 arasında değerler almış olup; en düşük metan gazı içeriği kabuksuz greyfurt cinsinden en yüksek metan gazı içeriği kabuklu Washington cinsinden elde edilmiştir. Turunçgil silajlarının yonca, mısır gibi silaj türlerinin metan gazı içeriklerine (%16-18) göre daha düşük metan gazı üretim kapasitesine sahip olması nedeniyle atmosfer’e yayılan sera gazı etkisi bakımından düşük kapasiteli az zararlı bir silaj türü olarak değerlendirilebilir. Metan gazı üretim kapasitesi açısından kabuksuz turunçgil silajlarının kabuklu turunçgil silajlarına göre daha avantajlı olduğunu söylenebilir. Sonuç olarak meyve suyu üretim tesislerinde her yıl gelişi güzel etrafa dökülen binlerce ton turunçgil posaları yem maliyetini düşürmek, kötü koku oluşumunu ve çevre kirliğini önlemek amacıyla uygun şekilde katkı maddesi olmadan silolanıp hayvan beslemede kullanılabilir.
Sensitivity of FAO Penman–Monteith reference evapotranspiration (ETo) to climatic variables under different climate types in Nigeria
Authors: Emeka Ndulue , Ikenna Onyekwelu , Okechukwu Michael , Chinenye Anyadike , Emmanuel Echiegu
Published: May 2020

Understanding the impact of changes in climatic variables on reference evapotranspiration (ETo) is important for predicting possible implications of climate change on the overall hydrology of an area. This study aimed to determine the effects of changes in ETo with respect to changes in climatic variables. In addition, the specific objective was to determine the sensitivity coefficients of ETo in seven different locations in Nigeria with distinct agroecology, namely Maiduguri (Sahel savannah), Sokoto (Sudan savannah), Kaduna (Guinea savannah), Jos (Montane), Enugu (Derived Savannah), Ibadan (tropical rainforest), and Port Harcourt (coastal). The results showed that ETo is most sensitive to changes in maximum temperature (Tmax) in Maiduguri, Sokoto, Kaduna, and Jos. In Enugu and Ibadan, ETo is most sensitive to changes in solar radiation (Rs), while in Port Harcourt, ETo is most sensitive to relative humidity (RH). Overall, based on the average annual sensitivity coefficients (SCs) of the study area, the SC is ranked in the order: RH > Rs > Tmax > U2 > Tmin. Also, the results showed positive SCs of ETo to Rs, Tmax, U2, Tmin, and negative SC for RH. This study can serve as a baseline for sustainable water management in the context of climate change and adapted to areas with a similar climate.
Machine Learning-Based Scoring Functions, Development and Applications with SAnDReS
Authors: Bitencourt-Ferreira Gabriela , Rizzotto Camila , de Azevedo Junior Walter Filgueira
Published: May 2020

Background:

Analysis of atomic coordinates of protein-ligand complexes can provide
three-dimensional data to generate computational models to evaluate binding affinity and
thermodynamic state functions. Application of machine learning techniques can create models
to assess protein-ligand potential energy and binding affinity. These methods show superior
predictive performance when compared with classical scoring functions available in docking
programs.

Objective:

Our purpose here is to review the development and application of the program
SAnDReS. We describe the creation of machine learning models to assess the binding affinity
of protein-ligand complexes.

Methods:

SAnDReS implements machine learning methods available in the scikit-learn library.
This program is available for download at https://github.com/azevedolab/sandres.
SAnDReS uses crystallographic structures, binding and thermodynamic data to create targeted
scoring functions.

Results:

Recent applications of the program SAnDReS to drug targets such as Coagulation
factor Xa, cyclin-dependent kinases and HIV-1 protease were able to create targeted scoring
functions to predict inhibition of these proteins. These targeted models outperform classical
scoring functions.

Conclusion:

Here, we reviewed the development of machine learning scoring functions to
predict binding affinity through the application of the program SAnDReS. Our studies show
the superior predictive performance of the SAnDReS-developed models when compared with
classical scoring functions available in the programs such as AutoDock4, Molegro Virtual
Docker and AutoDock Vina.
Chemoenzymatic Synthesis and Function of Chitin Derivatives
Authors: Ogata Makoto
Published: May 2020

Chitin, abundant biomass found in crab shells and other marine life, has wide applications in the production of food, pharmaceuticals, and cosmetics. Our recent studies have focused on the development of new functional materials by derivatizing chitin oligosaccharides and monosaccharides. For example, we have prepared various derivatives by chemoenzymatic synthesis using N-acetylglucosamine (GlcNAc) or chitin oligosaccharide prepared from chitin as starting materials. First, we have achieved the total synthesis of two secondary metabolites (furanodictine A and B) with neuronal differentiation-inducing activity on PC12 cells by using a simple heatinduced structural transformation of GlcNAc and esterification reaction. Second, we synthesized both a novel inhibitor that has facilitated a re-examination of the reaction mechanism of hen egg-white lysozyme, and a new substrate for assaying lysozyme activity by using chitin oligosaccharides as raw materials. Thus, the development of new materials by simple derivatization of chitin mono- or oligo-saccharides is paving the way for effective use of chitin.