Multifractal detrended cross-correlation analysis for two nonstationary signals

It is ubiquitous in natural and social sciences that two variables, recorded temporally or spatially in a complex system, are cross-correlated and possess multifractal features. We propose a new method called multifractal detrended cross-correlation analysis (MF-DXA) to investigate the multifractal behaviors in the power-law cross-correlations between two records in one or higher dimensions. The method is validated with cross-correlated 1D and 2D binomial measures and multifractal random walks. Application to two financial time series is also illustrated.Comment: 4 RevTex pages including 6 eps figure

Multifractal detrended fluctuation analysis in examining scaling properties of the spatial patterns of soil water storage

Knowledge about the scaling properties of soil water storage is crucial in transferring locally measured fluctuations to larger scales and vice-versa. Studies based on remotely sensed data have shown that the variability in surface soil water has clear scaling properties (i.e., statistically self similar) over a wider range of spatial scales. However, the scaling property of soil water storage to a certain depth at a field scale is not well understood. The major challenges in scaling analysis for soil water are the presence of localized trends and nonstationarities in the spatial series. The objective of this study was to characterize scaling properties of soil water storage variability through multifractal detrended fluctuation analysis (MFDFA). A field experiment was conducted in a sub-humid climate at Alvena, Saskatchewan, Canada. A north-south transect of 624-m long was established on a rolling landscape. Soil water storage was monitored weekly between 2002 and 2005 at 104 locations along the transect. The spatial scaling property of the surface 0 to 40 cm depth was characterized using the MFDFA technique for six of the soil water content series (all gravimetrically determined) representing soil water storage after snowmelt, rainfall, and evapotranspiration. For the studied transect, scaling properties of soil water storage are different between drier periods and wet periods. It also appears that local controls such as site topography and texture (that dominantly control the pattern during wet states) results in multiscaling property. The nonlocal controls such as evapotranspiration results in the reduction of the degree of multiscaling and improvement in the simple scaling. Therefore, the scaling property of soil water storage is a function of both soil moisture status and the spatial extent considered

Effectiveness of a simple lymphoedema treatment regimen in podoconiosis management in southern Ethiopia: one year follow-up

Background: Podoconiosis is a non-filarial elephantiasis caused by long-term barefoot exposure to volcanic soils in endemic areas. Irritant silicate particles penetrate the skin, causing a progressive, debilitating lymphoedema of the lower leg, often starting in the second decade of life. A simple patient-led treatment approach appropriate for resource poor settings has been developed, comprising (1) education on aetiology and prevention of podoconiosis, (2) foot hygiene (daily washing with soap, water and an antiseptic), (3) the regular use of emollient, (4) elevation of the limb at night, and (5) emphasis on the consistent use of shoes and socks. Methodology/Principal Findings: We did a 12-month, non-comparative, longitudinal evaluation of 33 patients newly presenting to one clinic site of a non-government organization (the Mossy Foot Treatment & Prevention Association, MFTPA) in southern Ethiopia. Outcome measures used for the monitoring of disease progress were (1) the clinical staging system for podoconiosis, and (2) the Amharic Dermatology Life Quality Index (DLQI), both of which have been recently validated for use in this setting. Digital photographs were also taken at each visit. Twenty-seven patients completed follow up. Characteristics of patients completing follow-up were not significantly different to those not. Mean clinical stage and lower leg circumference decreased significantly (mean difference -0.67 (95% CI -0.38 to -0.96) and -2.00 (95% CI -1.26 to -2.74), respectively, p<0.001 for both changes). Mean DLQI diminished from 21 (out of a maximum of 30) to 6 (p<0.001). There was a non-significant change in proportion of patients with mossy lesions (p = 0.375). Conclusions/Significance: This simple, resource-appropriate regimen has a considerable impact both on clinical progression and self-reported quality of life of affected individuals. The regimen appears ideal for scaling up to other endemic regions in Ethiopia and internationally. We recommend that further research in the area include analysis of cost-effectiveness of the regimen

Electrocatalytic reduction of carbon dioxide on gold–copper bimetallic nanoparticles: Effects of surface composition on selectivity

In this work, bimetallic nanoparticles (NPs) of Au and Cu are synthesized for the electrochemical reduction reaction of CO2 (CO2RR). It is known that the binding strength between the reduction intermediates and the electrocatalyst affects the selectivity of products, but how to correlate the performance with the surface composition, structure, and properties of a bimetallic electrocatalyst, instead of stoichiometric or bulk composition remains less discussed. AuCu and AuCu3 NPs with the size around similar to 8 nm were prepared. By excluding the size effect, the work studies the effects of surface composition and heteroatomic interaction on the selectivity and faradaic efficiency of the reduction products. Based on X-ray absorption spectroscopy (XAS), one can quantify the alloying extent and surface compositions of electrocatalysts, which are supposed to have the pivotal effects on the reaction pathways and the corresponding reduction products. It is found that high activity and notably improved CO selectivity of Au-Cu bimetallic NPs can be attributed to the heterometallic coordination and their electronic interactions. The reduction products were analyzed by gas chromatography and nuclear magnetic resonance (NMR) spectroscopy. Nearly 60 mA cm(-2) of current density was recorded at -0.91 V vs. RHE, and selectivity of 78 +/- 4.3% CO was obtained using AuCu. (C) 2020 Published by Elsevier Ltd

Incidence and predictors of puerperal sepsis among postpartum women at Debre Markos comprehensive specialized hospital, northwest Ethiopia: A prospective cohort study

Background: Puerperal sepsis is one of the leading causes of maternal mortality, particularly in low and middle-income countries where most maternal deaths occur. Women with puerperal sepsis are prone to long-term disabilities, such as chronic pelvic pain, blocked fallopian tubes, and secondary infertility. Besides this, puerperal sepsis has received less attention. For this reason, this study aimed to determine the incidence of puerperal sepsis and its predictors among postpartum women at Debre Markos Comprehensive Specialized Hospital. Methods: A prospective cohort study was conducted among 330 postpartum women from September 2020 to 2021. A pre-tested interviewer-administered questionnaire with a data extraction checklist was used to collect the data. Data were entered into Epi data 4.2 and analyzed using STATA 14.0. The incidence rate of puerperal sepsis was calculated, and a Kaplan-Meier survival curve was used to estimate the survival probability of developing puerperal sepsis. The cox-proportional hazards regression model was fitted to identify predictors of puerperal sepsis. Results: The study participants were followed for a total of 1685.3 person-week observations. The incidence rate of puerperal sepsis was 14.24 per 1,000 person-weeks. However, the overall incidence of puerperal sepsis was 7.27%. Not attending formal education [AHR: 3.55, 95% CI: (1.09–11.58)], a cesarean delivery [AHR: 4.50; 95% CI: (1.79–11.30)], premature rupture of the membranes [AHR: 3.25; 95% CI: (1.08–9.79)], complicated pregnancy [AHR: 4.80; 95% CI: (1.85–12.43)], being referred [AHR: 2.90; 95% CI: (1.10–7.65)], and not having birth preparedness and complication readiness plan [AHR: 2.95; 95% CI: (1.08–10.50)] were statistically significant predictors of puerperal sepsis. Conclusion: The incidence of puerperal sepsis was 7.27%. Not attending formal education, cesarean delivery, premature rupture of membranes, complicated pregnancy, referral status, and absence of birth preparedness and complication readiness plan were predictors associated with the incidence of puerperal sepsis

A morphological study of galaxies in ZwCl0024+1652, a galaxy cluster at redshift z ∼ 0.4

ABSTRACT: he well-known cluster of galaxies ZwCl0024+1652 at z ∼ 0.4 lacks an in-depth morphological classification of its central region. While previous studies provide a visual classification of a patched area, we used the public code called galaxy Support Vector Machine GALSVM) and HST/ACS data as well as the WFP2 master catalogue to automatically classify all cluster members up to 1 Mpc. GALSVM analyses galaxy morphologies through support vector machine (SVM). From the 231 cluster galaxies, we classified 97 as early types (ETs) and 83 as late types (LTs). The remaining 51 stayed unclassified (or undecided). By cross-matching our results with the existing visual classification, we found an agreement of 81 per cent. In addition to previous Zwcl0024 morphological classifications, 121 of our galaxies were classified for the first time in this work. In addition, we tested the location of classified galaxies on the standard morphological diagrams, colour–colour and colour–magnitude diagrams. Out of all cluster members, ∼20 per cent are emission-line galaxies, taking into account previous GLACE results. We have verified that the ET fraction is slightly higher near the cluster core and decreases with the clustercentric distance, while the opposite trend has been observed for LT galaxies. We found a higher fraction of ETs (54 per cent) than LTs (46 per cent) throughout the analysed central region, as expected. In addition, we analysed the correlation between the five morphological parameters (Abraham concentration, Bershady–Concelice concentration, asymmetry, Gini, and M20 moment of light) and the clustercentric distance, without finding a clear trend. Finally, as a result of our work, the morphological catalogue of 231 galaxies containing all the measured parameters and the final classification is available in the electronic form of this paper.MP also acknowledges support from the Spanish MINECO under projects AYA2013-42227-P and AYA2016-76682-C3-1-P- This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under the grants AYA2014-58861-C3-2-P, AYA2014-58861-C3-3-P, AYA2017-88007-C3-1-P, and AYA2017-88007-C3-2-P