Greedy Routing and the Algorithmic Small-World Phenomenom

The algorithmic small-world phenomenon, empirically established by Milgram's letter forwarding experiments from the 60s, was theoretically explained by Kleinberg in 2000. However, from today's perspective his model has several severe shortcomings that limit the applicability to real-world networks. In order to give a more convincing explanation of the algorithmic small-world phenomenon, we study greedy routing in a more realistic random graph model (geometric inhomogeneous random graphs), which overcomes the previous shortcomings. Apart from exhibiting good properties in theory, it has also been extensively experimentally validated that this model reasonably captures real-world networks. In this model, we show that greedy routing succeeds with constant probability, and in case of success almost surely finds a path that is an almost shortest path. Our results are robust to changes in the model parameters and the routing objective. Moreover, since constant success probability is too low for technical applications, we study natural local patching methods augmenting greedy routing by backtracking and we show that such methods can ensure success probability 1 in a number of steps that is close to the shortest path length. These results also address the question of Krioukov et al. whether there are efficient local routing protocols for the internet graph. There were promising experimental studies, but the question remained unsolved theoretically. Our results give for the first time a rigorous and analytical answer, assuming our random graph model

Lucentum : estudio historico

Dedicatoria autografa del autorMemoria premiada en los juegos florales del Casino de Alicante el 3 de Agosto de 188

Modern contraceptive use and associated factors during extended postpartum period among women who gave birth in the last 12 months at Northwest Ethiopia

Background: The extended postpartum period is a one-year follow-up period after giving birth, and it is critical for women to prevent unintended pregnancy and reduce the risk of maternal and child mortality by ensuring safe birth intervals. Many women, however, are unaware that they are at risk for pregnancy throughout this period. Hence, the aim of this study was to assess the utilization and associated factors of modern contraceptives during extended postpartum family planning (EPPP) in northwest Ethiopia. Methods: A community-based cross-sectional study design was conducted using 630 samples from October 01 to October 30, 2020, in northwest Ethiopia. The study participants were drawn through a multistage sampling technique and data were collected using structured questionnaires via interview. The collected data were entered into EpiData version 4.2 and exported into SPSS version 25.0 for management and further analysis. A bivariable logistic regression model was used to identify variables having an association with the outcome variable. In bivariable analysis, variables having P ≤ 0.25 were selected and entered into multivariable logistic regression analysis. Finally, in multivariable analysis, variables having P ≤ 0.05 with a 95% CI were declared as significantly associated with the outcome variable. Results: About 60.6% of women were using modern contraceptive during extended postpartum period. Mothers to partner discussion (AOR= 7.6, 95% CI: 4.20– 14.05), secondary educational status (AOR= 3.8, 95% CI: 1.36– 10.93), college and above educational status (AOR= 7, 95% CI: 1.92– 25.57), menstrual resumption (AOR= 9.2, 95% CI: 5.66– 15.12), sex resumed (AOR=8.5, 95% CI: 2.19– 33.58), fertility desire (AOR= 3.9, 95% CI: 1.99– 6.15), linkage to FP during child immunization (AOR= 2.7, 95% CI: 1.67– 4.50), and FP counseling during pregnancy (AOR=2, 95% CI: 1.25– 3.34) were significantly associated with outcome variable. Conclusion: Associating factors were identified as partner discussion, education, menstrual resumption, fertility desire, sexual resumption, FP counseling, and FP during child immunization. Improving mothers’ education and informing couples about the dangers of becoming pregnant before menstruation are critical

Rate and predictors of neonatal jaundice in northwest Ethiopia : prospective cohort study

Background: Neonatal jaundice is one of the most common clinical disorders occurred worldwide. About 1.1 million neonates develop jaundice per year globally and the vast majority of them found in sub-Saharan Africa and South Asia. There is a paucity of evidence on the incidence rate and predictors of neonatal jaundice in Ethiopia. Therefore, this study was aimed at determining the rate and predictors of neonatal jaundice in the northwest, Ethiopia. Methods: A prospective cohort study design was conducted at Debre Markos comprehensive, specialized Hospitals using 334 neonates from October 1, 2019, to June 30, 2020. Using a systematic random sampling technique, the study subjects were drawn. Data were entered into the Epi-DataTM Version 4.2 and analyzed using STATATM Version 14.0. The Kaplan-Meier survival curve was used to estimate the survival time. A generalized Log rank test was used to compare the survival curves of different categorical variables. Finally, both bi-variable and multivariable Cox-proportional hazards regression models were used to identify the predictors of neonatal jaundice. The Results: The overall incidence rate of jaundice among neonates was 4.5 per 100 person-hours. Long duration of labor [ARR = 3.5; 95% confidence interval (CI), (2.8– 8.7)], being male neonates [ARR= 5.2; 95% CI (3.5–7.3)], “O” blood group mothers [ARR = 4.5; 95% CI (3.4–10.3)], and having neonatal sepsis 3.4 [ARR=3.4; 95% CI: (2.5–6.1)] were predictors. Conclusion: The incidence rate of jaundice was higher in this study than the finding of the previous one. Being male, prolonged duration of labor, “O” blood group mothers and sepsis were the significant predictors. Hence, an effort has to be made to decrease the incidence rate of neonatal jaundice through improving newborn care and timely intervention for neonates with sepsis and delivered at a long duration of time as well as the neonates born from “o” blood type mothers are our recommendation

Estimating the number of cases of podoconiosis in Ethiopia using geostatistical methods

Background: In 2011, the World Health Organization recognized podoconiosis as one of the neglected tropical diseases. Nonetheless, the number of people with podoconiosis and the geographical distribution of the disease is poorly understood. Based on a nationwide mapping survey and geostatistical modelling, we predict the prevalence of podoconiosis and estimate the number of cases across Ethiopia. Methods: We used nationwide data collected in Ethiopia between 2008 and 2013. Data were available for 141,238 individuals from 1,442 villages in 775 districts from all nine regional states and two city administrations. We developed a geostatistical model of podoconiosis prevalence among adults (individuals aged 15 years or above), by combining environmental factors. The number of people with podoconiosis was then estimated using a gridded map of adult population density for 2015. Results: Podoconiosis is endemic in 345 districts in Ethiopia: 144 in Oromia, 128 in Southern Nations, Nationalities and People’s [SNNP], 64 in Amhara, 4 in Benishangul Gumuz, 4 in Tigray and 1 in Somali Regional State. Nationally, our estimates suggest that 1,537,963 adults (95% confidence intervals, 290,923-4,577,031 adults) were living with podoconiosis in 2015. Three regions (SNNP, Oromia and Amhara) contributed 99% of the cases. The highest proportion of individuals with podoconiosis resided in the SNNP (39%), while 32% and 29% of people with podoconiosis resided in Oromia and Amhara Regional States, respectively. Tigray and Benishangul Gumuz Regional States bore lower burdens, and in the remaining regions, podoconiosis was almost non-existent. Discussion: The estimates of podoconiosis cases presented here based upon the combination of currently available epidemiological data and a robust modelling approach clearly show that podoconiosis is highly endemic in Ethiopia. Given the presence of low cost prevention, and morbidity management and disability prevention services, it is our collective responsibility to scale-up interventions rapidly

Precipitation and Effect of Applied Surfactant on Distribution of Particle Size

Production of NiO by chemical precipitation is the approach utilized in this work. Materials mainly used in this project are nickel nitrate hex hydrate (as a basic material), sodium hydroxide (as a precipitator material), and the following surfactants (for reduction in particle size). Applied surfactants are in two kinds: polymeric (PVP, PEG) and cationic (CTAB) surfactants, 1.0 gram. Nanopowders properties are identified by TG, FTIR, XRD, SEM, and TEM. The results obtained confirm the presence of nickel oxide nanopowders produced during chemical precipitation

A large sample of low surface brightness disc galaxies from the SDSS- II. Metallicities in surface brightness bins

We study the spectroscopic properties of a large sample of Low Surface Brightness galaxies (LSBGs) (with B-band central surface brightness mu0(B)>22 mag arcsec^(-2)) selected from the Sloan Digital Sky Survey Data Release 4 (SDSS-DR4) main galaxy sample. A large sample of disk-dominated High Surface Brightness galaxies (HSBGs, with mu0(B)<22 mag arcsec^(-2)) are also selected for comparison simultaneously. To study them in more details, these sample galaxies are further divided into four subgroups according to mu0(B) (in units of mag arcsec^(-2)): vLSBGs (24.5-22.75),iLSBGs (22.75-22.0), iHSBGs (22.0-21.25), and vHSBGs (<21.25). The diagnostic diagram from spectral emission-line ratios shows that the AGN fractions of all the four subgroups are small (<9%). The 21,032 star-forming galaxies with good quality spectroscopic observations are further selected for studying their dust extinction, strong-line ratios, metallicities and stellar mass-metallicities relations. The vLSBGs have lower extinction values and have less metal-rich and massive galaxies than the other subgroups. The oxygen abundances of our LSBGs are not as low as those of the HII regions in LSBGs studied in literature, which could be because our samples are more luminous, and because of the different metallicity calibrations used. We find a correlation between 12+log(O/H) and mu0(B) for vLSBGs, iLSBGs and iHSBGs but show that this could be a result of correlation between mu0(B) and stellar mass and the well-known mass-metallicity relation. This large sample shows that LSBGs span a wide range in metallicity and stellar mass, and they lie nearly on the stellar mass vs. metallicity and N/O vs. O/H relations of normal galaxies. This suggests that LSBGs and HSBGs have not had dramatically different star formation and chemical enrichment histories.Comment: 14 pages, 11 figures, accepted for publication in MNRA

Analysis of maternal and newborn training curricula and approaches to inform future trainings for routine care, basic and comprehensive emergency obstetric and newborn care in the low- and middle-income countries: Lessons from Ethiopia and Nepal

Program managers routinely design and implement specialised maternal and newborn health trainings for health workers in low- and middle-income countries to provide better-coordinated care across the continuum of care. However, in these countries details on the availability of different training packages, skills covered in those training packages and the gaps in their implementation are patchy. This paper presents an assessment of maternal and newborn health training packages to describe differences in training contents and implementation approaches used for a range of training packages in Ethiopia and Nepal. We conducted a mixed-methods study. The quantitative assessment was conducted using a comprehensive assessment questionnaire based on validated WHO guidelines and developed jointly with global maternal and newborn health experts. The qualitative assessment was conducted through key informant interviews with national stakeholders involved in implementing these training packages and working with the Ministries of Health in both countries. Our quantitative analysis revealed several key gaps in the technical content of maternal and newborn health training packages in both countries. Our qualitative results from key informant interviews provided additional insights by highlighting several issues with trainings related to quality, skill retention, logistics, and management. Taken together, our findings suggest four key areas of improvement: first, training materials should be updated based on the content gaps identified and should be aligned with each other. Second, trainings should address actual health worker performance gaps using a variety of innovative approaches such as blended and self-directed learning. Third, post-training supervision and ongoing mentoring need to be strengthened. Lastly, functional training information systems are required to support planning efforts in both countries

Risk factors for brucellosis and knowledge-attitude practice among pastoralists in Afar and Somali regions of Ethiopia

BACKGROUND: Brucellosis is a neglected bacterial zoonotic disease with substantial economic impact on households. Pastoral communities are a potential risk group due to their way of life being closely interlinked with their large livestock herds. METHODOLOGY: A semi-structured questionnaire survey was conducted in households in the pastoral Afar and Somali (SRS) regions. All households had people and animals serologically tested for brucellosis. Questions were related to husbandry, consumption habits, and knowledge-attitude-practice towards the disease and zoonoses. Descriptive statistics and logistic analysis were performed to assess potential risk factors for having households with positive humans and/or animals. RESULT: 647 households were included in the survey. Herd brucellosis prevalence was 40.3 % (15.9-86.3 % in Afar; 4-72.2 % in SRS). Over half (56.3 %) of the households in Afar and 41.8 % in SRS had at least one human reactor. Nearly a quarter of the households (22.8 %), recalled abortions in goats in the last 12 months, whereas 52.5 % and 50.3 % recalled stillborn in all species and membrane retentions respectively. All respondents drank raw milk and discarded animal afterbirths in the direct surroundings with minimal protection. Risk factors for animal reactors were goat herd size, and goat abortion. There was no identified risk factor for having human reactors in households. None of the households knew about brucellosis. CONCLUSION: Although being endemic in Afar and SRS, Brucellosis is not known by the pastoralists. Brucellosis control programs will have to be tailored to the pastoral context, accounting for their mobility, large, multi-species herds and habits