45 research outputs found
Marijuana use associations with pulmonary symptoms and function in Tobacco smokers enrolled in the Subpopulations and Intermediate Outcome Measures in COPD study (SPIROMICS)
Background: Marijuana is often smoked via a filterless cigarette and contains similar chemical makeup as smoked tobacco. There are few publications describing usage patterns and respiratory risks in older adults or in those with chronic obstructive pulmonary disease (COPD). Methods: A cross-sectional analysis of current and former tobacco smokers from the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) study assessed associations between marijuana use and pulmonary outcomes. Marijuana use was defined as never, former (use over 30 days ago), or current (use within 30 days). Respiratory health was assessed using quantitative high-resolution computed tomography (HRCT) scans, pulmonary function tests and questionnaire responses about respiratory symptoms. Results: Of the total 2304 participants, 1130 (49%) never, 982 (43%) former, and 192 (8%) current marijuana users were included. Neither current nor former marijuana use was associated with increased odds of wheeze (odds ratio [OR] 0.87, OR 0.97), cough (OR 1.22; OR 0.93) or chronic bronchitis (OR 0.87; OR 1.00) when compared to never users. Current and former marijuana users had lower quantitative emphysema (P=0.004, P=0.03), higher percent predicted forced expiratory volume in 1 second (FEV1%) (P < 0.001, P < 0.001), and percent predicted forced vital capacity (FVC%) (p < 0.001, P < 0.001). Current marijuana users exhibited higher total tissue volume (P=0.003) while former users had higher air trapping (P < 0.001) when compared to never marijuana users. Conclusions: Marijuana use was found to have little to no association with poor pulmonary health in older current and former tobacco smokers after adjusting for covariates. Higher forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) was observed among current marijuana users. However, higher joint years was associated with more chronic bronchitis symptoms (e.g., wheeze), and this study cannot determine if long-term heavy marijuana smoking in the absence of tobacco smoking is associated with lung symptoms, airflow obstruction, or emphysema, particularly in those who have never smoked tobacco cigarettes
Collaborative Cohort of Cohorts for COVID-19 Research (C4R) Study: Study Design
The Collaborative Cohort of Cohorts for COVID-19 Research (C4R) is a national prospective study of adults comprising 14 established US prospective cohort studies. Starting as early as 1971, investigators in the C4R cohort studies have collected data on clinical and subclinical diseases and their risk factors, including behavior, cognition, biomarkers, and social determinants of health. C4R links this pre-coronavirus disease 2019 (COVID-19) phenotyping to information on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and acute and postacute COVID-related illness. C4R is largely population-based, has an age range of 18-108 years, and reflects the racial, ethnic, socioeconomic, and geographic diversity of the United States. C4R ascertains SARS-CoV-2 infection and COVID-19 illness using standardized questionnaires, ascertainment of COVID-related hospitalizations and deaths, and a SARS-CoV-2 serosurvey conducted via dried blood spots. Master protocols leverage existing robust retention rates for telephone and in-person examinations and high-quality event surveillance. Extensive prepandemic data minimize referral, survival, and recall bias. Data are harmonized with research-quality phenotyping unmatched by clinical and survey-based studies; these data will be pooled and shared widely to expedite collaboration and scientific findings. This resource will allow evaluation of risk and resilience factors for COVID-19 severity and outcomes, including postacute sequelae, and assessment of the social and behavioral impact of the pandemic on long-term health trajectories
EPFL (Swiss) fusion-fission hybrid experiment. Progress report, November 1, 1981-January 31, 1982
The trip provided an opportunity for extensive discussions with the staff of the Institut de Genie Atomique (IGA) of the Ecole Polytechnique Federale de Lausanne (EPFL). The discussions covered both the planning of the first series of experiments to be performed in the Hybrid Experiment (hereafter referred to as LOTUS) and the status of calculational work being performed at the University of Washington in support of the LOTUS project
Effects of climatic variability and possible climatic change on reliability of wheat cropping-A modelling approach
Wheat cropping in the northern sector of the Australian wheat belt has been expanding into a region with a more marginal moisture regime and a more variable climate than in the established cropping regions. To provide a sound basis for land use assessment, the likely reliability of cropping in this region was examined. Reliability included the likelihood of planting a wheat crop in any year and the likely yield of planted crops. Simulation studies, using an appropriate model of the cropping system and long-term rainfall records (92-year period), were used to derive yield probability distributions for sites throughout the region. The main features of the cropping system model developed are outlined. The yield probability distributions and associated economic analyses indicated that expansion of wheat cropping in this region was likely. Trends in simulated yield sequences were compared with analyses of factors associated with recent climatic change. Similarities of patterns suggested an association of rainfall and yield trends with climate forcing factors. Implications of this association are discussed. A better understanding of the action of the climate forcing factors is required before possible climatic change can be included in determining reliability of cropping
Phenology of sunflower cultivars. III. Models for prediction in field environments
Models of the daily rate of development for the stages emergence to head visible and head visible to first anthesis were formed for two sunflower cultivars (Helianthus annuus cvv. Sunfola 68-2 and Hysun 30). The models relate rate of development to photoperiod, daily mean temperature and relative cultivar sensitivity to photoperiod. They were derived from controlled-environment and field studies reported in the first two papers of this series. The two cultivars were found not to differ in sensitivity to temperature. The base temperature for development was found to decrease as the life cycle progressed. The models were validated on an independent data set and are applicable to the entire Australian continent, with one possible limitation on the temperature range at long photoperiods (14-18 h). The relationship of these models to the cultivar groups defined in the first paper of this series is discussed and a rapid method of determining relative cultivar sensitivity factors for new cultivars is outlined. The application of the models in planning for avoidance of frost by selecting the time of planting and the cultivar to be planted was demonstrated for three major sunflower-growing districts in Queensland. The possible use of these phenology models in conjunction with growth simulation models for studies of crop adaptation is discussed
Neutron yields from (. cap alpha. ,n) reactions of importance to reactors. Progress report, January 1, 1979-October 15, 1979. [Department of Nuclear Engineering, University of Washington, Seattle]
The goal of the first phase of this project is the accurate measurement of (..cap alpha..,n) yields from the isotopes of oxygen (especially /sup 18/O) in matrices that are characteristic of reactor fuels. Progress is reported for the period January 1, 1979 to October 1, 1979. During this time progress was achieved in the following areas: analysis of measurements of the near-equilibrium delayed neutron spectrum of /sup 240/Pu; design and construction of an assembly for the measurement of neutron yields from (..cap alpha..,n) reactions; analysis devoted to methods for calibration of the above assembly. Details of this work are given. 4 figures, 4 tables
Phenology of sunflower cultivars. I. Classification of responses
The phenology of commercial sunflower cultivars available to Queensland growers in 1979 was studied in monthly plantings over a 12-month period at Toowoomba in southern Queensland. By using pattern analysis procedures, the cultivars were classified into three maturity groups, viz. 'Very Quick', 'Quick' and 'Medium', based on the number of days from emergence to the head-visible stage of growth. Most of the cultivars belonged to the Quick and Medium maturity groups. Cultivar differences were most obvious for plantings in the cooler months (March to October). To classify new releases, one or two plantings during this period as well as one planting in summer is recommended. Sunfola 68-2 and Hysun 30 should be included in these plantings as cultivars representative of the two major maturity groups. The study showed that there was very little genetic variability in phenology in the present commercial cultivars and there was little difference in phenology among cultivars in the main summer planting period
On tactical crop management using seasonal climate forecasts and simulation modelling: a case study for wheat Procedimento de manejo cultural utilizando previsão climática e modelos de simulação: um estudo de caso para a cultura de trigo
The El Niño/Southern Oscillation phenomenon strongly influences rainfall distribution around the world. Using phases of the Southern Oscillation Index (SOI) allows a probabilistic forecast of future rainfall that can be useful to managers of agricultural systems. Using wheat as an example, we show in this study how the SOI phase system, when combined with a cropping systems simulation capability, can be used operationally to Improve tactical crop management and hence increase farm profits and/or decrease production risks. We show the validity of the approach for two contrasting locations, namely Dalby in Northern Australian and Piracicaba in Brazil At Dalby, highest median yields were achieved following a rapidly rising SOI phase in April/May and lowest median yields following a consistently negative phase. Conversely, highest median yields at Piracicaba followed a near zero April/May phase and lowest median yields when the phase was consistently positive. We show how tactical management options can range from crop or cultivar choice to nitrogen management and marketing of the future wheat crop.<br>O fenômeno El Niño/Oscilação Sul influencia marcadamente a distribuição de chuvas no mundo. O uso de fases de Ãndice de Oscilação Sul (IOS) permite uma previsão probabilÃstica da precipitação pluvial futura, que pode ser útil para o manejo de sistemas agrÃcolas. Usando-se trigo como exemplo, foi demonstrado nesse estudo, como o sistema de fases IOS, quando combinado com modelos de simulação de sistemas de cultivo, pode ser usado para melhorar o manejo tático de culturas e assim aumentar os lucros e/ou diminuir os riscos da produção agrÃcola. A validade desse método é mostrada para dois locais diferentes, Dalby, na Austrália e Piracicaba, no Brasil. Em Dalby, os maiores rendimentos médios foram obtidos após um aumento rápido na fase IOS em abril/maio e os menores rendimentos médios após uma fase negativa consistente. Em Piracicaba, os maiores rendimentos médios foram alcançados após uma fase próxima a zero em abril/maio e os menores rendimentos médios, quando a fase foi consistentemente positiva. É mostrado como as opções de manejo tático podem variar da escolha de cultivares ao manejo de nitrogênio e de mercado da cultura de trigo