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Aerosol and cloud water measurements of dimethylamine (DMA), the most abundant amine in this study, were conducted in semi-arid (Tucson, Arizona) and marine (Nucleation in California Experiment, NiCE; central coast of California) areas. In both regions, DMA exhibits a unimodal aerosol mass size distribution with a dominant peak between 0.18 and 0.56 µm. Particulate DMA concentrations increase as a function of marine biogenic emissions, sulfate, BVOC emissions, and aerosol-phase water. Such data supports biogenic sources of DMA, aminium salt formation, and partitioning of DMA to condensed phases. DMA concentrations exhibit positive correlations with various trace elements and most especially vanadium, which warrants additional investigation. Cloud water DMA levels are enhanced significantly during wildfire periods unlike particulate DMA levels, including in droplet residual particles, due to effective dissolution of DMA into cloud water and probably DMA volatilization after drop evaporation. DMA:NH+4 molar ratios peak between 0.18 and 1.0 µm depending on the site and time of year, suggesting that DMA competes better with NH3 in those sizes in terms of reactive uptake by particles.
RESUMO
A 2-year data set of measured CCN (cloud condensation nuclei) concentrations at 0.2 % supersaturation is combined with aerosol size distribution and aerosol composition data to probe the effects of aerosol number concentrations, size distribution and composition on CCN patterns. Data were collected over a period of 2 years (2012-2014) in central Tucson, Arizona: a significant urban area surrounded by a sparsely populated desert. Average CCN concentrations are typically lowest in spring (233 cm-3), highest in winter (430 cm-3) and have a secondary peak during the North American monsoon season (July to September; 372 cm-3). There is significant variability outside of seasonal patterns, with extreme concentrations (1 and 99 % levels) ranging from 56 to 1945 cm-3 as measured during the winter, the season with highest variability. Modeled CCN concentrations based on fixed chemical composition achieve better closure in winter, with size and number alone able to predict 82% of the variance in CCN concentration. Changes in aerosol chemical composition are typically aligned with changes in size and aerosol number, such that hygroscopicity can be parameterized even though it is still variable. In summer, models based on fixed chemical composition explain at best only 41% (pre-monsoon) and 36% (monsoon) of the variance. This is attributed to the effects of secondary organic aerosol (SOA) production, the competition between new particle formation and condensational growth, the complex interaction of meteorology, regional and local emissions and multi-phase chemistry during the North American monsoon. Chemical composition is found to be an important factor for improving predictability in spring and on longer timescales in winter. Parameterized models typically exhibit improved predictive skill when there are strong relationships between CCN concentrations and the prevailing meteorology and dominant aerosol physicochemical processes, suggesting that similar findings could be possible in other locations with comparable climates and geography.
RESUMO
Because of the advances in the treatment of cancer, patients live longer and require more comprehensive information in order to understand their illness, treatment procedure and role in the health care process. Each treatment involves combined therapeutic approaches, so information must be presented to the patient in such a way as to promote maximum understanding and acceptance. The purposes of this study were to explore and compare patients', nurses' and doctors' perception of the educational needs of cancer patients and to identify areas of agreement and disagreement in the perception of these needs by patients, nurses and doctors. Three groups took part in the study; 78 cancer patients, 39 nurses and 35 doctors. They all were selected from one general teaching hospital. Data were collected using a questionnaire, developed by the investigators. The questionnaire was made up of 2 sections; an importance rating scale and a knowledge/providing information rating scale. Each rating scale consisted of 20 specific informational items that were elicited through interviews with 60 cancer patients. The data were analyzed using percentages, means, Pearson correlation coefficients, t-test, and ANOVA. The results of this study were as follows; 1. Nurse subjects achieved a higher total score (85.6154) on the rating of importance than did the patients (81.5238) or the doctors (79.3125). The difference between the three group's total score was significant (F = 6.164, p less than .01) and the difference between the nurses' total score and doctors' was also statistically significant (t = 3.95, p less than .001). 2. On the whole, the rankings for the mean score of importance for the 20 items differed among the three groups of subjects. For the patient subjects, the highest mean ratings were for "the symptoms of recurring illness", "progress of illness", and "plan and duration of treatment" showing these to be the items that they considered important. The nurse subject felt that it was most important for oncology patients to know about "plan and duration of treatment", "how to minimize problems with loss of appetite, nausea, vomiting", and "amount of activity the patient can do around the work setting". Doctors felt it was most important for the patient to know about "prognosis of illness", "progress of illness", and "plan and duration of treatment". "Plan and duration of treatment" was the common item that all three groups perceived as important for patient learning.(ABSTRACT TRUNCATED AT 400 WORDS)