696 research outputs found

    Toward sustainable nitrogen management in vegetable production: balancing yield and nitrogen use efficiency

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    Non-Peer ReviewedCover crops (CC) have the potential to immobilize nutrients, especially nitrogen (N), that would otherwise be lost during post- or pre-harvest periods, leading to improved N management. However, information on how CCs influence N management for vegetable production are scarce. This study aims to determine agronomic responses (yield and N use efficiency, NUE) of three common prairie vegetable crops when produced with and without an overwintering rye CC. In 2017 and repeated in 2018, trials were initiated on a Sutherland clay soil (Dark Brown Chernozem) in Saskatoon for a fully phased broccoli-sweet corn-carrot sequence, with each crop type receiving five N fertilizer treatments (ranging from 0 to 300 kg N ha-1) arranged in a randomized complete block design with three replicates. After harvest, sub-plots were established with vs without a shoulder-season rye CC, and the effect followed into the subsequent growing season. Compared with zero N control, N fertilizer rate did not affect vegetable crop yields in either year, demonstrating the N-rich nature of the soil at this site. Depending on the crop, moderate to high application rates of N significantly reduced crop NUE; N rates above zero N control reduced NUE for sweet corn, rates above 75 kg N ha-1 reduced NUE for broccoli, all rates above 55 kg N ha-1 reduced NUE for the root crop in 2018. Subsequent to the CC in 2018, we found no N fertilizer by CC interaction for crop yields or NUE. The rye CC had no effect on crop yield or NUE for sweet corn or carrot, but significantly reduced broccoli yield and NUE. Regression analysis showed a decreasing trend in NUE with increasing N rates for all three vegetables, regardless of the CC. Our results suggest that the repetition of this experiment for a number of years is necessary to avoid excessive N application and improvement of productivity with cover crops

    Evaluating equality in prescribing Novel Oral Anticoagulants (NOACs) in England: the protocol of a Bayesian small area analysis

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    Background Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting about 1.6% of the population in England. Novel oral anticoagulants (NOACs) are approved AF treatments that reduce stroke risk. In this study, we estimate the equality in individual NOAC prescriptions with high spatial resolution in Clinical Commissioning Groups (CCGs) across England from 2014 to 2019. Methods A Bayesian spatio-temporal model will be used to estimate and predict the individual NOAC prescription trend on ‘prescription data’ as an indicator of health services utilisation, using a small area analysis methodology. The main dataset in this study is the “Practice Level Prescribing in England,” which contains four individual NOACs prescribed by all registered GP practices in England. We will use the defined daily dose (DDD) equivalent methodology, as recommended by the World Health Organization (WHO), to compare across space and time. Four licensed NOACs datasets will be summed per 1,000 patients at the CCG-level over time. We will also adjust for CCG-level covariates, such as demographic data, Multiple Deprivation Index, and rural-urban classification. We aim to employ the extended BYM2 model (space-time model) using the RStan package. Discussion This study suggests a new statistical modelling approach to link prescription and socioeconomic data to model pharmacoepidemiologic data. Quantifying space and time differences will allow for the evaluation of inequalities in the prescription of NOACs. The methodology will help develop geographically targeted public health interventions, campaigns, audits, or guidelines to improve areas of low prescription. This approach can be used for other medications, especially those used for chronic diseases that must be monitored over time

    Geographical and socioeconomic inequalities in female breast cancer incidence and mortality in Iran: A Bayesian spatial analysis of registry data

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    Background In Iran, trends in breast cancer incidence and mortality have generally been monitored at national level. The purpose of this study is to examine province-level disparities in age-standardised breast cancer incidence versus mortality from 2000 to 2010 and their association with socioeconomic status. Methods In this study, data from Iran’s national cancer and death registry systems, and covariates from census and household expenditure surveys were used. We estimated the age-standardised incidence and mortality rates in women aged more than 30 years for all 31 provinces in the consecutive time intervals 2000–2003, 2004–2007 and 2008–2010 using a Bayesian spatial model. Results Mean age-standardised breast cancer incidence across provinces increased over time from 15.0 per 100,000 people (95% credible interval 12.0,18.3) in 2000–2003 to 39.6 (34.5,45.1) in 2008–2010. The mean breast cancer mortality rate declined from 10.9 (8.3,13.8) to 9.9 (7.5,12.5) deaths per 100,000 people in the same period. When grouped by wealth index quintiles, provinces in the highest quintile had higher levels of incidence and mortality. In the wealthiest quintile, reductions in mortality over time were larger than those observed among provinces in the poorest quintile. Relative breast cancer mortality decreased by 16.7% in the highest quintile compared to 10.8% in the lowest quintile. Conclusions Breast cancer incidence has increased over time, with lower incidence in the poorest provinces likely driven by underdiagnoses or late-stage diagnosis. Although the reported mortality rate is still higher in wealthier provinces, the larger decline over time in these provinces indicates a possible future reversal, with the most deprived provinces having higher mortality rates. Ongoing analysis of incidence and mortality at sub-national level is crucial in addressing inequalities in healthcare systems and public health both in Iran and elsewhere

    The trend of national and subnational burden of maternal conditions in Iran from 1990 to 2013: The study protocol

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    Background: It is widely accepted that maternal mortality is a proxy for maternal health status. Maternal deaths only represent the top of the iceberg; morbidity due to maternal causes apart from maternal mortality, poses a huge burden on women's families. There is an excessive need to widen the research on maternal morbidity. Here, we explain the framework of our study on maternal conditions and their burden in Iran as a part of the National and Sub-national Burden of Diseases (NASBOD) study. Methods: A systematic search will be carried out for both published and unpublished data on maternal mortality and morbidity reported between 1985 and 2013. Data collected through systematic review and those obtained from national and sub-national surveys will be extracted in a data set. Two statistical models will be applied: Bayesian Autoregressive Multi-level models and Spatio-Temporal Regression models. Models will be used to overcome the problem of data gaps across provinces, years and age groups. Discussion: In order to control and manage maternal conditions and to make more efficient and cost-effective policies, there is an excessive need for data on the burden of such diseases. There are a few sub-national analyses of the burden of disease. In the current study, burden of maternal conditions will be assessed at national and sub-national levels in Iran between 1990 and 2013. The results of this study are undoubtedly required to provide comprehensive information at the national and provincial levels to administer interventions more effectively, since the priority based policies need regional assessments and comparisons

    National and subnational mortality effects of metabolic risk factors and smoking in Iran: a comparative risk assessment

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    <p>Abstract</p> <p>Background</p> <p>Mortality from cardiovascular and other chronic diseases has increased in Iran. Our aim was to estimate the effects of smoking and high systolic blood pressure (SBP), fasting plasma glucose (FPG), total cholesterol (TC), and high body mass index (BMI) on mortality and life expectancy, nationally and subnationally, using representative data and comparable methods.</p> <p>Methods</p> <p>We used data from the Non-Communicable Disease Surveillance Survey to estimate means and standard deviations for the metabolic risk factors, nationally and by region. Lung cancer mortality was used to measure cumulative exposure to smoking. We used data from the death registration system to estimate age-, sex-, and disease-specific numbers of deaths in 2005, adjusted for incompleteness using demographic methods. We used systematic reviews and meta-analyses of epidemiologic studies to obtain the effect of risk factors on disease-specific mortality. We estimated deaths and life expectancy loss attributable to risk factors using the comparative risk assessment framework.</p> <p>Results</p> <p>In 2005, high SBP was responsible for 41,000 (95% uncertainty interval: 38,000, 44,000) deaths in men and 39,000 (36,000, 42,000) deaths in women in Iran. High FPG, BMI, and TC were responsible for about one-third to one-half of deaths attributable to SBP in men and/or women. Smoking was responsible for 9,000 deaths among men and 2,000 among women. If SBP were reduced to optimal levels, life expectancy at birth would increase by 3.2 years (2.6, 3.9) and 4.1 years (3.2, 4.9) in men and women, respectively; the life expectancy gains ranged from 1.1 to 1.8 years for TC, BMI, and FPG. SBP was also responsible for the largest number of deaths in every region, with age-standardized attributable mortality ranging from 257 to 333 deaths per 100,000 adults in different regions.</p> <p>Discussion</p> <p>Management of blood pressure through diet, lifestyle, and pharmacological interventions should be a priority in Iran. Interventions for other metabolic risk factors and smoking can also improve population health.</p

    National and sub-national trend and burden of injuries in Iran, 1990-2013: A study protocol

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    Background: Worldwide, injuries are a major public health concern and make a considerable contribution to the disease burden. The present study is a component of the National and Subnational Burden of Diseases, Injuries, and Risk Factors from 1990 to 2013 (NASBOD) study in Iran, which was designed to investigate the burden of most important injuries (road traffic injuries, falls, burns, poisonings and drownings) at the national and sub-national levels in Iran. In this paper we explain definitions, organization, injuries selection process, data sources, data gathering methods, and data analyses of the national and sub-national burden of injuries study in Iran. Methods: The burden of most important injuries in current metric of DALYs at the national and sub-national levels in Iran over 1990-2013 will be estimated through comprehensive reviews of either published or national data sources. Statistical modeling will be used to impute the missing data on the burden of selected important injuries for each district-year. Conclusion: The results of present study can help health policy makers to plan more comprehensive and cost-effective strategies at national and sub-national level for prevention and control of burden caused by injuries

    Turnip mosaic potyvirus probably first spread to Eurasian brassica crops from wild orchids about 1000 years ago

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    Turnip mosaic potyvirus (TuMV) is probably the most widespread and damaging virus that infects cultivated brassicas worldwide. Previous work has indicated that the virus originated in western Eurasia, with all of its closest relatives being viruses of monocotyledonous plants. Here we report that we have identified a sister lineage of TuMV-like potyviruses (TuMV-OM) from European orchids. The isolates of TuMV-OM form a monophyletic sister lineage to the brassica-infecting TuMVs (TuMV-BIs), and are nested within a clade of monocotyledon-infecting viruses. Extensive host-range tests showed that all of the TuMV-OMs are biologically similar to, but distinct from, TuMV-BIs and do not readily infect brassicas. We conclude that it is more likely that TuMV evolved from a TuMV-OM-like ancestor than the reverse. We did Bayesian coalescent analyses using a combination of novel and published sequence data from four TuMV genes [helper component-proteinase protein (HC-Pro), protein 3(P3), nuclear inclusion b protein (NIb), and coat protein (CP)]. Three genes (HC-Pro, P3, and NIb), but not the CP gene, gave results indicating that the TuMV-BI viruses diverged from TuMV-OMs around 1000 years ago. Only 150 years later, the four lineages of the present global population of TuMV-BIs diverged from one another. These dates are congruent with historical records of the spread of agriculture in Western Europe. From about 1200 years ago, there was a warming of the climate, and agriculture and the human population of the region greatly increased. Farming replaced woodlands, fostering viruses and aphid vectors that could invade the crops, which included several brassica cultivars and weeds. Later, starting 500 years ago, inter-continental maritime trade probably spread the TuMV-BIs to the remainder of the world

    Quality evaluation of national cancer registry system in Iran: Study protocol

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    Background: Cancer registry can be a very important component of health information system in developing countries. Routine collection of data and ongoing monitoring of their quality can have a crucial role in priority setting and evidence-based policy making for controlling cancers and trends follow-up in low and middle-income countries. Evaluation of cancer registered data consists of four important components including: comparability, completeness, validity, and timeliness. Similar frameworks are utilized in different countries all over the world.Methods and Materials: We will use the national annual cancer registry reports in Iran alone or perhaps along with other Iranian published reports about childhood cancer incidence to determine the stability and trend of incidence rates over time and compare above mentioned reports with childhood cancer incidence data reported by other countries through a systematic review as well as in some cases meta-analysis in order to assess data quality. Data will also be collected from other sources such as death certificates to estimate mortality rates and other different methods will also be additionally applied, by use of which death certificates would be utilized to assess the quality of data, too. Conclusion: As the first step for proper measuring incidence rate of all types of cancers all over the country, we will assess and evaluate reported national cancer registry data in Iran in order to estimate the national burden of cancers in 1990-2013

    Insight into blood pressure targets for universal coverage of hypertension services in Iran: the 2017 ACC/AHA versus JNC 8 hypertension guidelines

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    BACKGROUND: We compared the prevalence, awareness, treatment, and control of hypertension in Iran based on two hypertension guidelines; the 2017 ACC/AHA -with an aggressive blood pressure target of 130/80 mmHg- and the commonly used JNC8 guideline cut-off of 140/90 mmHg. We shed light on the implications of the 2017 ACC/AHA for population subgroups and high-risk individuals who were eligible for non-pharmacologic and pharmacologic therapies. METHODS: Data was obtained from the Iran national STEPS 2016 study. Participants included 27,738 adults aged ≥25 years as a representative sample of Iranians. Regression models of survey design were used to examine the determinants of prevalence, awareness, treatment, and control of hypertension. RESULTS: The prevalence of hypertension based on JNC8 was 29.9% (95% CI: 29.2-30.6), which soared to 53.7% (52.9-54.4) based on the 2017 ACC/AHA. The percentage of awareness, treatment, and control were 59.2% (58.0-60.3), 80.2% (78.9-81.4), and 39.1% (37.4-40.7) based on JNC8, which dropped to 37.1% (36.2-38.0), 71.3% (69.9-72.7), and 19.6% (18.3-21.0), respectively, by applying the 2017 ACC/AHA. Based on the new guideline, adults aged 25-34 years had the largest increase in prevalence (from 7.3 to 30.7%). They also had the lowest awareness and treatment rate, contrary to the highest control rate (36.5%) between age groups. Compared with JNC8, based on the 2017 ACC/AHA, 24, 15, 17, and 11% more individuals with dyslipidaemia, high triglycerides, diabetes, and cardiovascular disease events, respectively, fell into the hypertensive category. Yet, based on the 2017 ACC/AHA, 68.2% of individuals falling into the hypertensive category were eligible for receiving pharmacologic therapy (versus 95.7% in JNC8). LDL cholesterol< 130 mg/dL, sufficient physical activity (Metabolic Equivalents≥600/week), and Body Mass Index were found to change blood pressure by - 3.56(- 4.38, - 2.74), - 2.04(- 2.58, - 1.50), and 0.48(0.42, 0.53) mmHg, respectively. CONCLUSIONS: Switching from JNC8 to 2017 ACC/AHA sharply increased the prevalence and drastically decreased the awareness, treatment, and control in Iran. Based on the 2017 ACC/AHA, more young adults and those with chronic comorbidities fell into the hypertensive category; these individuals might benefit from earlier interventions such as lifestyle modifications. The low control rate among individuals receiving treatment warrants a critical review of hypertension services
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