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

Mortality rate and predictors among patients with breast cancer at a referral hospital in northwest Ethiopia: A retrospective follow-up study

BACKGROUND Breast cancer is one of the common global health concerns that affects2 1 million women each year and causes the highest number of cancer related morbidity and mortality among women The objective of this study was to determine the mortality rate and its predictors among breast cancer patients at the referral hospitals in northwest Ethiopia METHODS A retrospective follow up study was conducted on breast cancer patients registered between February 01 2015 and February 28 2018 They were selected by simple random sampling using computer generated method and followed until February 29 2020 in Amhara region referral hospital A pre tested data extraction checklist was used to collect data from the registration book and patient medical records The collected data were entered into Epi Data version 3 1 and exported to STATA version 14 for analysis The mortality rate by person year observation was computed The Kaplan Meier survival curve with the log rank test was used to estimate the survival probabilities of the patients Bivariate and multivariate Cox regression model was used to identify predictors of mortality RESULTS The overall mortality rate of breast cancer was 16 9 per 100 person years observation The median survival time was 38 3 IQR 26 23 49 4 months Independent predictors of breast cancer mortality was Clinical stage IV and stage III aHR 10 44 95 CI 8 02 11 93 and aHR 9 43 95 CI 6 29 11 03respectively number of positive lymph node in the category of 10 and more and number of positive lymph node within the category of 4 9 aHR 12 58 95 CI 5 2 30 46 and aHR 4 78 95 CI 2 19 10 43respectively co morbidities aHR 1 5 95 CI 1 01 2 21 Postmenopausal aHR 2 03 95 CI 1 37 3 histologic grade III aHR 2 12 95 CI 1 26 3 55 and not received hormonal therapy aHR 2 19 95 CI 1 52 3 15 were independent predictors of mortality CONCLUSION The overall mortality rate was 16 9 per 100 person years The finding was higher compared to high income countries Advanced clinical stage c

Addis Ababa’s water crisis: challenges and opportunities

Addis Ababa’s water supply is insufficient to meet current needs, leading to intermittent water supplies which are increasing inequalities in water access depending on access to household storage and finances to develop private wells. Proposals to expand surface water storage will not fully meet the growing demand from the population and expanding industries. Groundwater depletion, land for expanding reservoir storage, water quality and unreliable energy supplies limit opportunities for increasing water provision. Action is needed now to better monitor and manage groundwater use, and to improve the conjunctive use of surface and groundwater to support sustainability for Addis Ababa’s water supplies