69 research outputs found

    A bi-objective column generation algorithm for the multi-commodity minimum cost flow problem

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    We present a column generation algorithm for solving the bi-objective multi-commodity minimum cost flow problem. This method is based on the bi-objective simplex method and Dantzig–Wolfe decomposition. The method is initialised by optimising the problem with respect to the first objective, a single objective multi-commodity flow problem, which is solved using Dantzig–Wolfe decomposition. Then, similar to the bi-objective simplex method, our algorithm iteratively moves from one non-dominated extreme point to the next one by finding entering variables with the maximum ratio of improvement of the second objective over deterioration of the first objective. Our method reformulates the problem into a bi-objective master problem over a set of capacity constraints and several single objective linear fractional sub-problems each over a set of network flow conservation constraints. The master problem iteratively updates cost coefficients for the fractional sub-problems. Based on these cost coefficients an optimal solution of each sub-problem is obtained. The solution with the best ratio objective value out of all sub-problems represents the entering variable for the master basis. The algorithm terminates when there is no entering variable which can improve the second objective by deteriorating the first objective. This implies that all non-dominated extreme points of the original problem are obtained. We report on the performance of the algorithm on several directed bi-objective network instances with different characteristics and different numbers of commodities

    Molecular detection of Brucella species in patients suspicious of Brucellosis from Zanjan, Iran

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    Abstract Brucella is an intracellular pathogen capable of infecting animals and humans. The aim of this study was to identify Brucella spp in sera of high risk individuals by a polymerase chain reaction (PCR)-based method. A total of 180 patients suspected to have Brucellosis were examined by serological tests. To establish a PCR protocol for diagnosis of active brucellosis, DNA was extracted from the serum samples by using a commercial kit. PCR amplification was done for detection of Brocella DNA using BCSP31 target gene and IS711 locus. The PCR assay showed that an amplicon of 223 bp was obtained in 73.8% (133/180) of the tested sera using primers (B 4 /B 5 ) derived from a gene encoding the 31-kDa Brucella abortus antigen. In another PCR, an amplicon of 498 bp was obtained in 63.8% (115/180) of the samples using Brucella abortus-specific primers derived from a locus adjacent to the 3'-end of IS711, and also an amplicon of 731 bp was produced in 4.4% (8/180) of the tested samples using Brucella melitensis-specific primers. When the Wright method was used as a gold standard, the sensitivity and specificity of the PCR technique for genus identification were found to be 96 and 80.7%, respectively. However, the sensitivity value obtained with the species-specific PCR method was 82%, and specificity was similar to that previous reported. This is the first report of a high frequency of Brucella abortus in patients suspicious of Brucellosis from the Zanjan province

    Mesenchymal Stem Cell Injection in Two Patients Suffer From Chronic Discogenic Low Back Pain

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    Background: Discogenic low back pain is one of the leading causes of pain and disability across the world.  A growing interest in the area of regenerative medicine, led by an improved understanding of the role of mesenchymal stem cells in tissue homeostasis and repair.Cases Report: We had two patients suffered from chronic discogenic low back pain. They were underwent injection of intra-discal 1.5 cc of Adipose Derived Mesenchymal Stem Cells (ADMSC) and followed up for 6 months. After this period of time, there was a significant reduction in both VAS and ODI scores in patients.Conclusion: These data warrant further studies so that we can enhance our understanding of the other unknown mechanisms, which may exist behind stem cell injection. If the effectiveness of such injection to reduce pain and improve function is shown in the upcoming studies, it may provide a new insight for increasing this method of treatment as a proper option in the near future

    The study of some limnological study of the Kan river in the catchment area of the Persian Gulf Martyrs Lake (Chitgar), Tehran trophic index in Anzali lagoon

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    This study focused on identification phytoplankton, zooplankton, benthos, fishes and relationship between biotic and abiotic parameters at three stations in the Kan river during 2014. This study identified 19 phytoplankton taxa. The findings showed, the diatoms abundance were dominated in the river. The chlorophytes abundance were recorded the lowest abundance in this study. The nutrients and water temperature were the significant abiotic parameters to increase cyanophytes and chlorophytes abundance in the Kan river. This study identified 26 zooplankton taxa. The Rotatoria and Protozoa abundance were dominated in the Kan river. Based on CCA, there was no correlation between abundance zooplankton and abiotic parameters. The biodiversity index of plankton was between 1.8 and 2 and the lake situation is located in the mesotrophic category. The study of the Kan river fishes showed, only one endemic fish species Capoeta bohsei. The length (between 38 and 270 mm, average 144±86 mm) and weight (between 1.1 and 356 g, average 108.8±146.7 g) of the C. bohsei were varied during the study period. The 19 benthos taxa were identified. The Ephemeroptera was most abundant in the benthos groups. The classification of river based on biology indicator and environmental parameters confimed that water quality is located in the moderate category

    Monitoring of fisheries resources in artificial reefs in east of Kish Island waters

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    Artificial reefs are manmade materials deployed under water in order to improve environment and increase the exploitation of fishing area. Usage of artificial technic has developed due to increase of world population and need to supply of protein, aim to restoring of natural specially rehabilitation of demersal fishes. It has effected to increase the production in order sustainable exploitation. Coasts and Islands have destruction due to over harvesting from ecosystems and other activities by humans and natural, these caused many aquatic as demersal fishes has endangered in Persian Gulf and Oman Sea. The artificial reef is one way or method that can improve the environment and restore the aquatic. Iranian fisheries has established an artificial reefs area in west of Kish Island. This area has studied during one year, Data of assembled fishes and physical sampling were collected in seasonal during spring, summer, autumn and wintered. There were tow treatment for sampling as artificial reefs site and a control site. Collected data has analyzed and evaluated by SPSS and Exel. The results showed that there was significant difference between the sites and assembled fishes in artificial reefs were more than control site. Consequently the artificial reefs can be a tool and technic to improve the marine environment and increase the production of fishes, especially the demersal fishes

    Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

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    Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

    Prevalence and attributable health burden of chronic respiratory diseases, 1990–2017: A systematic analysis for the global burden of disease study 2017

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    © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license Background: Previous attempts to characterise the burden of chronic respiratory diseases have focused only on specific disease conditions, such as chronic obstructive pulmonary disease (COPD) or asthma. In this study, we aimed to characterise the burden of chronic respiratory diseases globally, providing a comprehensive and up-to-date analysis on geographical and time trends from 1990 to 2017. Methods: Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, we estimated the prevalence, morbidity, and mortality attributable to chronic respiratory diseases through an analysis of deaths, disability-adjusted life-years (DALYs), and years of life lost (YLL) by GBD super-region, from 1990 to 2017, stratified by age and sex. Specific diseases analysed included asthma, COPD, interstitial lung disease and pulmonary sarcoidosis, pneumoconiosis, and other chronic respiratory diseases. We also assessed the contribution of risk factors (smoking, second-hand smoke, ambient particulate matter and ozone pollution, household air pollution from solid fuels, and occupational risks) to chronic respiratory disease-attributable DALYs. Findings: In 2017, 544·9 million people (95% uncertainty interval [UI] 506·9–584·8) worldwide had a chronic respiratory disease, representing an increase of 39·8% compared with 1990. Chronic respiratory disease prevalence showed wide variability across GBD super-regions, with the highest prevalence among both males and females in high-income regions, and the lowest prevalence in sub-Saharan Africa and south Asia. The age-sex-specific prevalence of each chronic respiratory disease in 2017 was also highly variable geographically. Chronic respiratory diseases were the third leading cause of death in 2017 (7·0% [95% UI 6·8–7·2] of all deaths), behind cardiovascular diseases and neoplasms. Deaths due to chronic respiratory diseases numbered 3 914 196 (95% UI 3 790 578–4 044 819) in 2017, an increase of 18·0% since 1990, while total DALYs increased by 13·3%. However, when accounting for ageing and population growth, declines were observed in age-standardised prevalence (14·3% decrease), age-standardised death rates (42·6%), and age-standardised DALY rates (38·2%). In males and females, most chronic respiratory disease-attributable deaths and DALYs were due to COPD. In regional analyses, mortality rates from chronic respiratory diseases were greatest in south Asia and lowest in sub-Saharan Africa, also across both sexes. Notably, although absolute prevalence was lower in south Asia than in most other super-regions, YLLs due to chronic respiratory diseases across the subcontinent were the highest in the world. Death rates due to interstitial lung disease and pulmonary sarcoidosis were greater than those due to pneumoconiosis in all super-regions. Smoking was the leading risk factor for chronic respiratory disease-related disability across all regions for men. Among women, household air pollution from solid fuels was the predominant risk factor for chronic respiratory diseases in south Asia and sub-Saharan Africa, while ambient particulate matter represented the leading risk factor in southeast Asia, east Asia, and Oceania, and in the Middle East and north Africa super-region. Interpretation: Our study shows that chronic respiratory diseases remain a leading cause of death and disability worldwide, with growth in absolute numbers but sharp declines in several age-standardised estimators since 1990. Premature mortality from chronic respiratory diseases seems to be highest in regions with less-resourced health systems on a per-capita basis. Funding: Bill & Melinda Gates Foundation

    The unfinished agenda of communicable diseases among children and adolescents before the COVID-19 pandemic, 1990-2019: a systematic analysis of the Global Burden of Disease Study 2019

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    BACKGROUND: Communicable disease control has long been a focus of global health policy. There have been substantial reductions in the burden and mortality of communicable diseases among children younger than 5 years, but we know less about this burden in older children and adolescents, and it is unclear whether current programmes and policies remain aligned with targets for intervention. This knowledge is especially important for policy and programmes in the context of the COVID-19 pandemic. We aimed to use the Global Burden of Disease (GBD) Study 2019 to systematically characterise the burden of communicable diseases across childhood and adolescence. METHODS: In this systematic analysis of the GBD study from 1990 to 2019, all communicable diseases and their manifestations as modelled within GBD 2019 were included, categorised as 16 subgroups of common diseases or presentations. Data were reported for absolute count, prevalence, and incidence across measures of cause-specific mortality (deaths and years of life lost), disability (years lived with disability [YLDs]), and disease burden (disability-adjusted life-years [DALYs]) for children and adolescents aged 0-24 years. Data were reported across the Socio-demographic Index (SDI) and across time (1990-2019), and for 204 countries and territories. For HIV, we reported the mortality-to-incidence ratio (MIR) as a measure of health system performance. FINDINGS: In 2019, there were 3·0 million deaths and 30·0 million years of healthy life lost to disability (as measured by YLDs), corresponding to 288·4 million DALYs from communicable diseases among children and adolescents globally (57·3% of total communicable disease burden across all ages). Over time, there has been a shift in communicable disease burden from young children to older children and adolescents (largely driven by the considerable reductions in children younger than 5 years and slower progress elsewhere), although children younger than 5 years still accounted for most of the communicable disease burden in 2019. Disease burden and mortality were predominantly in low-SDI settings, with high and high-middle SDI settings also having an appreciable burden of communicable disease morbidity (4·0 million YLDs in 2019 alone). Three cause groups (enteric infections, lower-respiratory-tract infections, and malaria) accounted for 59·8% of the global communicable disease burden in children and adolescents, with tuberculosis and HIV both emerging as important causes during adolescence. HIV was the only cause for which disease burden increased over time, particularly in children and adolescents older than 5 years, and especially in females. Excess MIRs for HIV were observed for males aged 15-19 years in low-SDI settings. INTERPRETATION: Our analysis supports continued policy focus on enteric infections and lower-respiratory-tract infections, with orientation to children younger than 5 years in settings of low socioeconomic development. However, efforts should also be targeted to other conditions, particularly HIV, given its increased burden in older children and adolescents. Older children and adolescents also experience a large burden of communicable disease, further highlighting the need for efforts to extend beyond the first 5 years of life. Our analysis also identified substantial morbidity caused by communicable diseases affecting child and adolescent health across the world. FUNDING: The Australian National Health and Medical Research Council Centre for Research Excellence for Driving Investment in Global Adolescent Health and the Bill & Melinda Gates Foundation
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