Wildland fire-atmosphere interaction generates complex turbulence patterns, organized across multiple scales, which inform fire-spread behaviour, firebrand transport, and smoke dispersion. Here, we utilize wavelet-based techniques to explore the characteristic temporal scales associated with coherent patterns in the measured temperature and the turbulent fluxes during a prescribed wind-driven (heading) surface fire beneath a forest canopy. We use temperature and velocity measurements from tower-mounted sonic anemometers at multiple heights.
View Article and Find Full Text PDFPrescribed fire is an increasingly important tool in restoring ecological conditions and reducing uncontrolled wildfire. Prescribed burn techniques could reduce public health impacts associated with wildfire smoke exposure. However, there have been few assessments of the health impacts of prescribed burning, and potential vulnerabilities among populations exposed to smoke from prescribed fires.
View Article and Find Full Text PDFIncreasing trends in wildfire severity can partly be attributed to fire exclusion in the past century which led to higher fuel accumulation. Mechanical thinning and prescribed burns are effective techniques to manage fuel loads and to establish a higher degree of control over future fire risk, while restoring fire prone landscapes to their natural states of succession. However, given the complexity of interactions between fine scale fuel heterogeneity and wind, it is difficult to assess the success of thinning operations and prescribed burns.
View Article and Find Full Text PDFEpidemiological studies consistently show an association between wildfire-related smoke exposure and adverse respiratory health. We conducted a systematic review of evidence in published literature pertaining to heterogeneity of respiratory effects from this exposure in North America. We calculated the within-study ratio of relative risks (RRR) and 95% confidence intervals (CI) to examine heterogeneity of effect by population subgroup, and then summarized the RRRs using meta-analysis.
View Article and Find Full Text PDFMany studies have shown the importance of anthropogenic greenhouse gas emissions in contributing to observed upward trends in the occurrences of temperature extremes over the U.S. However, few studies have investigated the contributions of internal variability in the climate system to these observed trends.
View Article and Find Full Text PDFPlant Biol (Stuttg)
March 2007
Because seedlings and mature trees do not necessarily respond similarly to O(3) stress, it is critically important that exposure systems be developed that allow exposure of seedlings through to mature trees. Here we describe three different O(3) Free-Air Exposure Systems that have been used successfully for exposure at all growth stages. These systems of spatially uniform O(3) release have been shown to provide reliable O(3) exposure with minimal, if any, impact on the microclimate.
View Article and Find Full Text PDFThe United States and Canada currently use exposure-based metrics to protect vegetation from O(3). Using 5 years (1999-2003) of co-measured O(3), meteorology and growth response, we have developed exposure-based regression models that predict Populus tremuloides growth change within the North American ambient air quality context. The models comprised growing season fourth-highest daily maximum 8-h average O(3) concentration, growing degree days, and wind speed.
View Article and Find Full Text PDFA series of 6-alkyl and 6-arylcarbamoyloximinopyrazolo[3,4-b][1,4]diazepines was prepared and evaluated for fungicidal, insecticidal and herbicidal activity. No one compound showed a general effect but individual compounds exhibited specific activities.
View Article and Find Full Text PDFZ Gesamte Inn Med
October 1981
Even nowadays the therapy of severe, particularly of contrast remedy-induced hyperthyroidism is not without any problems. According to reports in literature the application of lithium salts seems to be an expedient from this dilemma. We controlled the effect of a short-term lithium therapy of 7 days in combination with methimazole in comparison to a group with methimazole monotherapy.
View Article and Find Full Text PDFTo develop nonacidic, nonsteroidal anti-inflammatory agents without GI complications, a series of asymmetric triazines was synthesized and evaluated for anti-inflammatory efficacy in the carrageenan-induced pedal edema assay. Toxicity was estimated by determination of approximate LD50 values in mice. Twenty-five compounds possessed activity comparable to the standard, indomethacin.
View Article and Find Full Text PDFIn an effort to develop antihypertensive agents with peripheral vasodilator activity, a series of 40 novel 3-hydrazino-5-phenyl-1,2,4-triazines (II) were synthesized and evaluated in the spontaneously hypertensive rat assay (SHR assay). Based on the performance of the structurally related standard, hydralazine (I), 15 triazines were active. Thirteen of these hypotensive triazines possessed LD50 values in the mouse greater than I (LD50 = 100 mg/kg); only one active triazine had an LD50 value greater than 300 mg/kg (11d).
View Article and Find Full Text PDFIn an effort to develop nonacidic, nonsteroidal, antiinflammatory agents without gastrointestinal complications, a series of cyanobenzenes was synthesized for antiinflammatory evaluation. Twenty-seven substituted isophthalonitriles, 19 trimesonitriles, 30 benzonitriles, and 16 terephthalonitriles were tested in the rat utilizing the carrageenan-induced pedal edema assay. Based on the performance of phenylbutazone in this assay (43.
View Article and Find Full Text PDFTo explore the effect of lipophilicity on antilipidemic activity in the Triton WR-1339 induced hyperlipidemic rat model we synthesized the 6-cyclohexyl, phenyl, and phenoxy analogs of ethyl chroman-2-carboxylate. Results obtained were analyzed in light of the biological activity observed for the 6-chloro-substituted and unsubstituted chromans, the 6-chlorochroman-4-one ester, and the 6-chloro-, phenyl-, and phenoxychromone esters. The suggestion is made that chromones likely exert their antilipidemic effects by a somewhat different set of mechanisms than do the chromans and clofibrate.
View Article and Find Full Text PDFThe behaviour of the blood glucose, the insulin secretion, the free fatty acids, of glycerol and of the triglycerides after glucose tolerance test was examined in 66 patients with condition after myocardial infarction. 16 of the 34 patients loaded with an oral glucose tolerance test and 25 of the 31 patients loaded with an intravenous glucose infusion test showed disturbances of the glucose tolerance. The insulin secretion was significantly different neither in normal nor disturbed or lying in the borderline region glucose tolerance.
View Article and Find Full Text PDFElectrophoreis of enterotoxin into a middle liquid section of a polyacrylamide gel column enhances recovery for serological assay.
View Article and Find Full Text PDFAppl Microbiol
February 1968
Serological tests were used to determine the slope of the thermal inactivation curve of crude enterotoxin A in Veronal buffer (pH 7.2), and the resulting z value was 27.8 C.
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