Fractional and fractal processes applied to cryptocurrencies price series.

Introduction: Cryptocurrencies have been attracting the attention from media, investors, regulators and academia during the last years. In spite of some scepticism in the financial area, cryptocurrencies are a relevant subject of academic research. Objectives: In this paper, several tools are adopted as an instrument that can help market agents and investors to more clearly assess the cryptocurrencies price dynamics and, thus, guide investment decisions more assertively while mitigating risks. Methods: We consider three methods, namely the Auto-Regressive Integrated Moving Average (ARIMA), Auto-Regressive Fractionally Integrated Moving Average (ARFIMA) and Detrended Fluctuation Analysis, and three indices given by the Hurst and Lyapunov exponents or the Fractal Dimension. This information allows assessing the behaviour of the time series, such as their persistence, randomness, predictability and chaoticity. Results: The results suggest that, except for the Bitcoin, the other cryptocurrencies exhibit the characteristic of mean reverting, showing a lower predictability when compared to the Bitcoin. The results for the Bitcoin also indicate a persistent behavior that is related to the long memory effect. Conclusions: The ARFIMA reveals better predictive performance than the ARIMA for all cryptocurrencies. Indeed, the obtained residual values for the ARFIMA are smaller for the auto and partial auto correlations functions, as well as for confidence intervals.

The recovery of global stock markets indices after impacts due to pandemics.

The COVID-19 brings back the debate about the impact of disease outbreaks in economies and financial markets. The error correction terms (ECT) and cointegration processing tools have been applied in studies for identifying possible transmission mechanisms between distinct time series. This paper adopts the vector error correction model (VECM) to investigate the dynamic coupling between the pandemics (e.g., the COVID-19, EBOLA, MERS and SARS) and the evolution of key stocks exchange indices (e.g., Dow-Jones, S&P 500, EuroStoxx, DAX, CAC, Nikkei, HSI, Kospi, S&P ASX, Nifty and Ibov). The results show that the shocks caused by the diseases significantly affected the markets. Nonetheless, except for the COVID-19, the stock exchange indices reveal a sustained and fast recovering when an identical length time window of 79 days is analyzed. In addition, our findings contribute to point a higher volatility for all financial indices during the COVID-19, a strong impact over the Ibov-Brazil and its poor recover when compared to the other indices.

Phlebotomines (Diptera: Psychodidae) and Mosquitoes (Diptera: Culicidae) Surrounding an Environmental Protection Zone in the Metropolitan Region of Natal: Use of Light-Emitting Diode (LED) Bulbs in Entomological Surveillance.

Entomological surveillance is very important for parasite and arbovirus vector control programs. Light traps with incandescent bulbs are used to attract insects and analyze the factors that contribute to the occurrence of species surrounding an environmental protection zone. Phlebotomine and mosquito abundance and their diversity were analyzed. Captures occurred monthly using six CDC light traps with two incandescent bulbs, two blue and two red LED lights. A total of 2211 phlebotomines of seven species and 4486 mosquitoes belonging to 20 taxa were captured. Different phlebotomine and mosquito species were found in the forest and peridomestic environments, with a predominance of the sand fly Evandromyia walkeri (Newstead) and the mosquito Coquillettidia venezuelensis (Theobald). There was a significant difference in the abundance of sand flies captured with the three bulbs tested, the blue bulb being the most efficient. The Shannon-Wiener diversity index showed that the trap equipped with a red LED light obtained a higher value than that of the blue LED and incandescent bulb. Analyses showed that the potential vectors and non-vectors of the two groups circulate between the forest and the peridomestic environment, suggesting an adaptation process of species to the altered environment. An incandescent light bulb can be substituted by an LED bulb, without compromising the sensitivity of the method. A blue LED is indicated for the abundant capture of mosquitoes and sand flies, while a red LED obtains a better result in terms of species diversity per capture.

Absolute income is a better predictor of coverage by skilled birth attendance than relative wealth quintiles in a multicountry analysis: comparison of 100 low- and middle-income countries.

BACKGROUND: Having high-quality data available by 2020, disaggregated by income, is one of the Sustainable Development Goals (SGD). We explored how well coverage with skilled birth attendance (SBA) is predicted by asset-based wealth quintiles and by absolute income. METHODS: We used data from 293 national surveys conducted in 100 low and middle-income countries (LMICs) from 1991 to 2014. Data on household income were computed using national income levels and income inequality data available from the World Bank and the Standardized World Income Inequality Database. Multivariate regression was used to explore the predictive capacity of absolute income compared to the traditional measure of quintiles of wealth index. RESULTS: The mean SBA coverage was 68.9% (SD: 24.2), compared to 64.7% (SD: 26.6) for institutional delivery coverage. Median daily family income in the same period was US$ 6.4 (IQR: 3.5-14.0). In cross-country analyses, log absolute income predicts 51.5% of the variability in SBA coverage compared to 22.0% predicted by the wealth index. For within-country analysis, use of absolute income improved the understanding of the gap in SBA coverage among the richest and poorest families. Information on income allowed identification of countries - such as Burkina Faso, Cambodia, Egypt, Nepal and Rwanda - which were well above what would be expected solely from changes in income. CONCLUSION: Absolute income is a better predictor of SBA and institutional delivery coverage than the relative measure of quintiles of wealth index and may help identify countries where increased coverage is likely due to interventions other than increased income.

The Inverse Equity Hypothesis: Analyses of Institutional Deliveries in 286 National Surveys.

OBJECTIVES: To test the inverse equity hypothesis, which postulates that new health interventions are initially adopted by the wealthy and thus increase inequalities-as population coverage increases, only the poorest will lag behind all other groups. METHODS: We analyzed the proportion of births occurring in a health facility by wealth quintile in 286 surveys from 89 low- and middle-income countries (1993-2015) and developed an inequality pattern index. Positive values indicate that inequality is driven by early adoption by the wealthy (top inequality), whereas negative values signal bottom inequality. RESULTS: Absolute inequalities were widest when national coverage was around 50%. At low national coverage levels, top inequality was evident with coverage in the wealthiest quintile taking off rapidly; at 60% or higher national coverage, bottom inequality became the predominant pattern, with the poorest quintile lagging behind. CONCLUSIONS: Policies need to be tailored to inequality patterns. When top inequalities are present, barriers that limit uptake by most of the population must be identified and addressed. When bottom inequalities exist, interventions must be targeted at specific subgroups that are left behind.

Calibration of raw accelerometer data to measure physical activity: A systematic review.

Most of calibration studies based on accelerometry were developed using count-based analyses. In contrast, calibration studies based on raw acceleration signals are relatively recent and their evidences are incipient. The aim of the current study was to systematically review the literature in order to summarize methodological characteristics and results from raw data calibration studies. The review was conducted up to May 2017 using four databases: PubMed, Scopus, SPORTDiscus and Web of Science. Methodological quality of the included studies was evaluated using the Landis and Koch's guidelines. Initially, 1669 titles were identified and, after assessing titles, abstracts and full-articles, 20 studies were included. All studies were conducted in high-income countries, most of them with relatively small samples and specific population groups. Physical activity protocols were different among studies and the indirect calorimetry was the criterion measure mostly used. High mean values of sensitivity, specificity and accuracy from the intensity thresholds of cut-point-based studies were observed (93.7%, 91.9% and 95.8%, respectively). The most frequent statistical approach applied was machine learning-based modelling, in which the mean coefficient of determination was 0.70 to predict physical activity energy expenditure. Regarding the recognition of physical activity types, the mean values of accuracy for sedentary, household and locomotive activities were 82.9%, 55.4% and 89.7%, respectively. In conclusion, considering the construct of physical activity that each approach assesses, linear regression, machine-learning and cut-point-based approaches presented promising validity parameters.

The contribution of poor and rural populations to national trends in reproductive, maternal, newborn, and child health coverage: analyses of cross-sectional surveys from 64 countries.

BACKGROUND: Coverage levels for essential interventions aimed at reducing deaths of mothers and children are increasing steadily in most low-income and middle-income countries. We assessed how much poor and rural populations in these countries are benefiting from national-level progress. METHODS: We analysed trends in a composite coverage indicator (CCI) based on eight reproductive, maternal, newborn, and child health interventions in 209 national surveys in 64 countries, from Jan 1, 1994, to Dec 31, 2014. Trends by wealth quintile and urban or rural residence were fitted with multilevel modelling. We used an approach akin to the calculation of population attributable risk to quantify the contribution of poor and rural populations to national trends. FINDINGS: From 1994 to 2014, the CCI increased by 0·82 percent points a year across all countries; households in the two poorest quintiles had an increase of 0·99 percent points a year, which was faster than that for the three wealthiest quintiles (0·68 percent points). Gains among poor populations were faster in lower-middle-income and upper-middle-income countries than in low-income countries. Globally, national level increases in CCI were 17·5% faster than they would have been without the contribution of the two poorest quintiles. Coverage increased more rapidly annually in rural (0·93 percent points) than urban (0·52 percent points) areas. INTERPRETATION: National coverage gains were accelerated by important increases among poor and rural mothers and children. Despite progress, important inequalities persist, and need to be addressed to achieve the Sustainable Development Goals. FUNDING: UNICEF, Wellcome Trust.

Socioeconomic Correlates of Sedentary Behavior in Adolescents: Systematic Review and Meta-Analysis.

BACKGROUND: The body of evidence on associations between socioeconomic status (SES) and sedentary behaviors in adolescents is growing. OBJECTIVES: The overall aims of our study were to conduct a systematic review and meta-analysis of this evidence and to assess whether (1) the associations between SES and sedentary behavior are consistent in adolescents from low-middle-income and from high-income countries, (2) the associations vary by domain of sedentary behavior, and (3) the associations vary by SES measure. METHODS: We performed a systematic literature search to identify population-based studies that investigated the association between SES and sedentary behavior in adolescents (aged 10-19 years). Only studies that presented risk estimates were included. We conducted meta-analyses using random effects and univariate meta-regression and calculated pooled effect sizes (ES). RESULTS: Data from 39 studies were included; this provided 106 independent estimates for meta-analyses. Overall, there was an inverse association between SES and sedentary behavior (ES 0.89; 95 % confidence interval [CI] 0.81-0.98). However, the direction of the association varied: in high-income countries, SES was inversely associated with sedentary behavior (ES 0.67; 95 % CI 0.62-0.73), whereas in low-middle-income countries, there was a positive association between SES and sedentary behavior (ES 1.18; 95 % CI 1.04-1.34). In high-income countries, the associations were strongest for screen time (ES 0.68; 95 % CI 0.62-0.74) and television (TV) time (ES 0.58; 95 % CI 0.49-0.69), whereas in low-middle-income countries, the associations were strongest for 'other' screen time (i.e., computer, video, study time, but not including TV time) (ES 1.38; 95 % CI 1.07-1.79). All indicators of SES were negatively associated with sedentary behavior in high-income countries, but only resources (income and assets indexes) showed a significant positive association in low-middle-income countries. CONCLUSION: The associations between SES and sedentary behavior are different in high- and low-middle-income countries, and vary by domain of sedentary behavior. These findings suggest that different approaches may be required when developing intervention strategies for reducing sedentary behavior in adolescents in different parts of the world.

Physical Activity and Safety From Crime Among Adults: A Systematic Review.

BACKGROUND: The aim of this study was to review the evidence to date on the association between physical activity and safety from crime. METHODS: Articles with adult populations of 500+ participants investigating the association between physical activity and safety from crime were included. A methodological quality assessment was conducted using an adapted version of the Downs and Black checklist. RESULTS: The literature search identified 15,864 articles. After assessment of titles, abstracts and full-texts, 89 articles were included. Most articles (84.3%) were derived from high-income countries and only 3 prospective articles were identified. Articles presented high methodological quality. In 38 articles (42.7%), at least one statistically significant association in the expected direction was reported (ie, safety from crime was positively associated with physical activity). Nine articles (10.1%) found an association in the unexpected direction and 42 (47.2%) did not find statistically significant associations. The results did not change when we analyzed articles separately by sex, age, type of measurement, or domains of physical activity evaluated. CONCLUSION: The current evidence, mostly based on cross-sectional studies, suggests a lack of association between physical activity and safety from crime. Prospective studies and natural experiments are needed, particularly in areas with wide crime variability.

Autocalibration of accelerometer data for free-living physical activity assessment using local gravity and temperature: an evaluation on four continents.

Wearable acceleration sensors are increasingly used for the assessment of free-living physical activity. Acceleration sensor calibration is a potential source of error. This study aims to describe and evaluate an autocalibration method to minimize calibration error using segments within the free-living records (no extra experiments needed). The autocalibration method entailed the extraction of nonmovement periods in the data, for which the measured vector magnitude should ideally be the gravitational acceleration (1 g); this property was used to derive calibration correction factors using an iterative closest-point fitting process. The reduction in calibration error was evaluated in data from four cohorts: UK (n = 921), Kuwait (n = 120), Cameroon (n = 311), and Brazil (n = 200). Our method significantly reduced calibration error in all cohorts (P < 0.01), ranging from 16.6 to 3.0 mg in the Kuwaiti cohort to 76.7 to 8.0 mg error in the Brazil cohort. Utilizing temperature sensor data resulted in a small nonsignificant additional improvement (P > 0.05). Temperature correction coefficients were highest for the z-axis, e.g., 19.6-mg offset per 5°C. Further, application of the autocalibration method had a significant impact on typical metrics used for describing human physical activity, e.g., in Brazil average wrist acceleration was 0.2 to 51% lower than uncalibrated values depending on metric selection (P < 0.01). The autocalibration method as presented helps reduce the calibration error in wearable acceleration sensor data and improves comparability of physical activity measures across study locations. Temperature ultization seems essential when temperature deviates substantially from the average temperature in the record but not for multiday summary measures.

Brazilian adults' sedentary behaviors by life domain: population-based study.

BACKGROUND: There is rapidly-emerging evidence on the harmful health effects of sedentary behaviors. The aim of this paper was to quantify time in sedentary behaviors and document socio-demographic variations in different life domains among adults. METHODS: A population-based survey was carried out in 2012 through face-to-face interviews with Brazilian adults aged 20+ years (N = 2,927). Information about time spent sedentary in a typical weekday was collected for five different domains (workplace, commuting, school/university, watching TV, and computer use at home). Descriptive and bivariate analyses examined variations in overall and domain-specific sedentary time by gender, age, educational attainment and socioeconomic position. RESULTS: On average, participants reported spending 5.8 (SD 4.5) hours per day sitting. The median value was 4.5 (interquartile range: 2.5-8) hours. Men, younger adults, those with higher schooling and from the wealthiest socioeconomic groups had higher overall sedentary scores. TV time was higher in women, older adults and among those with low schooling and socioeconomic position. Sedentary time in transport was higher in men, younger adults, and participants with high schooling and high socioeconomic position. Computer use at home was more frequent among young adults and those from high socioeconomic groups. Sitting at work was higher in those with higher schooling and from the wealthiest socioeconomic groups. Sedentary behavior at school was related inversely to age and directly to schooling. CONCLUSION: Patterns of sedentary behavior are different by life domains. Initiatives to reduce prolonged sitting among Brazilian adults will be required on multiple levels for different life domains.

Occurrence of white rust (Albugo ipomoeae-panduratae) on Ipomoea acuminata in the brazilian mid-west

Spontaneous plants of Ipomoea acuminata ("morning glory") exhibiting white rust pustules were found in a field crop area of Planaltina, DF, in the fall season of 2010 and the disease causal agent was identified as Albugo ipomoea-panduratae (Oomycota). No reports of the association between A. ipomoea-panduratae and I. acuminata were known in Brazil previously to 2010. A reference specimen was deposited at the University of Brasilia Mycological Reference Collection.

Occurrence of white rust (Albugo ipomoeae-panduratae) on Ipomoea acuminate In the brazilian mid-west.

Spontaneous plants of Ipomoea acuminata ("morning glory") exhibiting white rust pustules were found in a field crop area of Planaltina, DF, in the fall season of 2010 and the disease causal agent was identified as Albugo ipomoea-panduratae (Oomycota). No reports of the association between A. ipomoea-panduratae and I. acuminata were known in Brazil previously to 2010. A reference specimen was deposited at the University of Brasilia Mycological Reference Collection.

A Tomato Fruit Rot Caused by Trichothecium roseum in Brazil.

Fruit rots caused by distinct fungal pathogens are commonly observed on tomatoes (Solanum lycopersicum L.) throughout all major production areas in Brazil. Samples of fruits displaying white mycelial growth associated with a profuse salmon-color sporulation were collected in greenhouse-grown tomatoes in Brasília-DF in February 2011. The isolated fungus displayed pink-to-white colonies containing several conidiophores with conidia. Mycelia displayed hyaline hyphae as much as 4 µm in diameter; conidiophores were simple or branched, 112 to 300 (360) µm long, and 2 to 4 µm wide. Conidia were produced in basipetal chains (frequently clustered), were ellipsoidal to pyriform with oblique and prominent truncate basal scars, two-celled, hyaline, and (14-) 16 to 26 (-28) × (6-) 7 to 10 (-12) µm. These characteristics allocated the specimen to Trichothecium roseum (Pers.). Koch's postulates were fulfilled for one fungal isolate by either spraying 10 intact fruits or by placing a drop of a spore suspension (adjusted to 105 conidia/ml) into three to five wounds created on 10 mature fruits of each of two tomato cultivars (Santa Clara and Dominador) by puncturing each fruit with a sterile needle. Five fruits of each cultivar were treated with sterile water as the mock-inoculated control treatment. Identical symptoms to those of the original fruit were observed only in the T. roseum-inoculated samples 5 to 7 days after using both inoculation procedures. Total DNA was extracted from a pure colony of the fungus growing on potato dextrose agar medium and used as template in PCR assays with the internal transcribed spacer (ITS)-4 (5'-TCCTCCGCTTATTGATATGC-3') and ITS-5 (5'-GGAAGTAAAAGTCGTAACAAGG-3') primer pair (2). A single amplicon of approximately 630 bp was observed and directly sequenced. Sequence analysis of the Brazilian isolate (GenBank No. JN081877) indicated identity levels of 99% with T. roseum isolates reported on Leucadendron xanthoconus in South Africa (GenBank No. EU552162) and isolates from strawberry fruits in South Korea (GenBank No. HM355750). However, phylogenetic analysis was unable to discriminate isolates of T. roseum from Passalora (GenBank No. EF432764) and Fusarium (GenBank No. GU183369) isolates, confirming the low genetic variability of the ITS region in Hypocreales (3). T. roseum has been reported to be infecting greenhouse tomatoes in the United States (4) and causing postharvest disease of tomatoes in Argentina (1). To our knowledge, this is the first report of T. roseum infecting greenhouse tomatoes in Brazil. References: (1) G. Dal Bello. Australas. Plant Dis. Notes 3:103, 2008. (2) N. L. Glass and G. C. Donaldson. Appl. Environ. Microbiol. 61:1323, 1995. (3) L. Lombard et al. Stud. Mycol. 66:31, 2010. (4) A. W. Welch, Jr. et al. Plant Dis. Rep. 59:255, 1975.

Plurispermiopsis: a new capnodiaceous genus from the Brazilian Cerrado.

A new ascomycete genus placed in family Capnodiaceae found in the Brazilian Cerrado is described and designated Plurispermiopsis, type species P. cerradensis.

Physical activity advice: short report from a population-based study in Brazil.

PURPOSE: To evaluate the prevalence of physical activity advice, the source of the information, and the types of recommendation in a population-based sample of adults living in South Brazil. METHODS: Population-based study including 972 adults living in Pelotas, Brazil. The outcome variable was based on the following question: "Has anyone ever recommended you to practice physical activity"? If the answer was positive, we asked who was responsible for the prescription (an open question, which was categorized later) and which recommendation was done. RESULTS: The prevalence of physical activity advice was 56.2% (95% CI 52.3-60.1). Physical activity advice was mostly done by physicians (92.5%). Walking was, by far, the most frequent recommendation. Females were more likely to receive advice for physical activity practice than males (OR 1.74; 95% CI 1.30-2.31). Age, economic level, body mass index and leisure-time physical activity were positively associated with physical activity advice, while self-reported health presented an inverse association with the outcome. CONCLUSIONS: The prevalence of physical activity advice was high in this sample, suggesting that the Brazilian health system is incorporating physical activity in its routine.

[Terminolateral esophagojejunostomy after gastrectomy with the biofragmentable anastomosis ring in the dog model]. / End-zu-Seit Osophagojejunostomie mit dem biofragmentierbaren Anastomosenring nach Gastrektomie am Hundemodell.

INTRODUCTION: Esophagojejunostomy after total gastrectomy still remains a high risk anastomosis with a considerable morbidity and mortality. The majority of these anastomoses are performed by the intraluminal stapler technique, yet stenoses are a known late complication even after an uneventful postoperative course. In the present study, the osophagojejunostomy with the biofragmentable anastomosis ring (BAR) was examined in dogs. METHODS: 28 dogs were randomized into a group of manual suture (n = 14) and a BAR-group (n = 14). After gastrectomy, the esophagojejunostomy was performed by hand-suture with polypropylene 4-0 in the manual suture group, and with the 25/1.5 mm BAR in the BAR-group. In both groups the Roux-en-Y jejunojejunostomy was performed by hand-suture. The dogs were evaluated on postoperative days 4, 7 and 14 with regard to macroscopy, bursting strength, tissue hydroxyproline and histology. RESULTS: There was one leakage without clinical effect in the hand-sewn group on postoperative day 4; there was no leak in the BAR-group. In observing fibre-free enteral feeding, neither functional disorders nor obstruction of the BAR were observed. The general anastomosis parameters were matchable between the groups. CONCLUSION: The infracarinal BAR-esophagojejunostomy is comparable to the hand-sewn anastomosis in the dog-model.

The impact of syphilis, HIV-1, and HIV-2 on pregnancy outcome in Bissau, Guinea-Bissau.

BACKGROUND: Syphilis remains a major cause of fetal loss and neonatal mortality in sub-Saharan Africa. Guinea-Bissau is the epicenter of the HIV-2 epidemic, and little is known about the impact of HIV-2 on pregnancy. GOAL: To understand better the impact of maternal syphilis and HIV-2 on the outcomes of pregnancy in Bissau, Guinea-Bissau. STUDY DESIGN: Using a case-control design, maternal syphilis and HIV-2 seropositive results were examined in relation to adverse outcomes of pregnancy. From June 1997 to April 1998, women presenting to the Simao Mendes hospital of Bissau for a delivery or a spontaneous abortion were invited to participate in the study, and 1341 women were enrolled. The 743 control subjects were women who had delivered a term neonate with a birthweight greater than 2500 g that survived the first 28 days of life. The cases were classified into five groups of mothers according to the outcome of pregnancy: stillbirths (n = 185), spontaneous abortions (n = 89), premature deliveries (n = 256), small-for-gestation-age babies (n = 55), and neonatal deaths (n = 13). RESULTS: Among the control subjects, the prevalences of serologic syphilis and HIV infection were 3.9% and 7.9%, respectively. Positive syphilis serology results together with a rapid plasma reagin titer of 1:16 or more were associated with delivery of a stillborn (adjusted odds ratio [AOR], 6.05) and premature delivery (AOR, 2.98). In Bissau, the population-attributable risk fraction of syphilis was 7.2% (95% CI, 2.2-11.9%) for stillbirths and only 2.4% (95% CI, 0-5.8%) for premature deliveries. Spontaneous abortions, delivery of a small-for-gestation-age baby, and neonatal deaths were not associated with positive syphilis serology results. None of these pregnancy outcomes was significantly associated with HIV-2 infection. CONCLUSIONS: The effect of syphilis on the outcome of pregnancy in West Africa is similar to that reported from other parts of Africa. However, because the prevalence of positive syphilis serology results is relatively low, the impact of screening for syphilis on the outcome of pregnancy is likely to be relatively modest. The findings from this study confirm the absence of association between HIV-2 and an adverse pregnancy outcome.

Case report: cytomegalovirus infection as a cause of acute portal vein thrombosis.

We report on the case of a 31-year-old woman who developed acute portal vein thrombosis during the course of an acute cytomegalovirus (CMV) infection. We suggest a relationship between CMV infection, its endothelial cell-damaging effects and portal vein thrombosis.