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Combustion emissions and strong Santa Ana winds had pronounced effects on patterns and levels of ambient ozone (O3) in southern California during the extensive wildland fires of October 2007. These changes are described in detail for a rural receptor site, the Santa Margarita Ecological Reserve, located among large fires in San Diego and Orange counties. In addition, O3 changes are also described for several other air quality monitoring sites in the general area of the fires. During the first phase of the fires, strong, dry and hot northeasterly Santa Ana winds brought into the area clean continental air masses, which resulted in minimal diurnal O3 fluctuations and a 72-h average concentration of 36.8 ppb. During thesecond phase of the fires, without Santa Ana winds present and air filled with smoke, daytime O3 concentrations steadily increased and reached 95.2 ppb while the lowest nighttime levels returned to w0 ppb. During that period the 8-h daytime average O3 concentration reached 78.3 ppb, which exceeded the federal standard of 75 ppb. After six days of fires, O3 diurnal concentrations returned to pre-fire patterns and levels.

Bangladesh pursued a policy of import-substituting industrialisation until 1990 when trade was liberalised and exports promoted. This paper examines the impact of trade liberalisation on the export–income relationship using cointegration methods. Results show that trade liberalisation increased export growth but had no effect on the structure of the long-run export–income relationship. Impulse responses support the export-led growth hypothesis and Bangladesh should complete its trade liberalisation agenda to promote economic growth.

Nitric acid (HNO3) vapor is a significant component of air pollution. Dry deposition of HNO3 is thought to be a major contributor to terrestrial loading of anthropogenically-derived nitrogen (N), but many questions remain regarding the physico-chemical process of deposition and the biological responses to accumulation of dry-deposited HNO3 on surfaces. To examine these processes experimentally, a continuously stirred tank reactor (CSTR) fumigation system has been constructed. This system enables simultaneous fumigation at several concentrations in working volumes 1.3 m dia by 1.3 m ht, allowing for simultaneous fumigation of many experimental units. Evaluation of the system indicates that it is appropriate for long-term exposures of several months duration and capable of mimicking patterns of diurnal atmospheric HNO3 concentrations representative of areas with different levels of pollution.

There has been increasing interest in measuring the productive performance of health care services, since the mid-1980s. This paper reviews this literature and, in particular, the concept and measurement of efficiency and productivity. Concerning measurement, we focus on the use of Data Envelopment Analysis (DEA), a technique particularly appropriate when multiple outputs are produced from multiple inputs. Applications to hospitals and to the wider context of general health care are reviewed and the empirical evidence from both the USA and Europe (EU) is that public rather than private provision is more efficient.

Empirical analyses of calorie intake response to income have produced strong disagreement with some showing a low and statistically insignificant effect. Using cross‐sectional data for 41 developing countries in 1992, calorie intake is significantly determined by per capita income, income distribution, income growth, urbanization, food aid and socio‐cultural factors. The estimated income elasticity is significant, around 0.07, while that with respect to urbanization is about 0.17. Inadequate calorie intake is caused by low levels of economic development in general, rather than by low income in particular. Policies aimed at alleviating inadequate calorie intake should not focus on income alone.

The Royal Women's Hospital, Melbourne, is a tertiary referral hospital with over 7,000 deliveries per year. We report 3 cases of phaeochromocytoma in pregnancy at the hospital in the 20-year period since 1976. The first case was unsuspected and resulted in a maternal death. The subsequent 2 cases were diagnosed antenatally with successful outcomes for both mother and baby. The 3 cases demonstrate the importance of an early antenatal diagnosis and the special management problems of phaeochromocytoma in pregnancy. The diagnosis of phaeochromocytoma should be considered in any pregnant women with severe hypertension, particularly if presenting before 20 weeks' gestation, labile, or associated with sweating, palpitations or headaches.

Young 'Valencia' orange trees (Citrus sinensis(L) Osbeck) were grown for four years in large open-top chambers with ambient (nonfiltered) air or in outside air to determine any effects of the chambers on the air pollutant susceptibility of the trees. Long-term ozone average concentrations (12 hours, growing season) were 8% lower, and cumulative ozone dose (hourly values >0.1 microL/L) was 29% lower in ambient chambers compared to outside air. Fruit yields were much higher (>39%) for ambient chamber trees than for outside trees over three harvests, due at least partly to less fruit drop during the growing season for ambient chamber trees. Ambient chamber trees were much larger than outside trees and produced over twice as much leaf material over four years of study. Leaves on ambient chamber trees were larger and less dense than on outside trees. Leaves on ambient chamber trees were under more stress than leaves on outside trees during summer months; with lower stomatal conductances (14% average) and transpiration rates (12%), and more negative leaf water pressure potentials (28%). In contrast, leaves on ambient chamber trees had higher net photosynthetic rates (13%) and higher leaf starch concentrations prior to tree flowering (31%), than leaves on outside trees. more » While these results indicated large long-term impacts on tree growth which must be considered when using open-top chambers, they did not indicate any net effect of chambers on the air pollutant susceptibility of trees which would limit the usefulness of chamber tree data for air quality impact assessment purposes. « less

We have assessed, in 200 patients, the determinants of the reversal time of competitive neuromuscular block by anticholinesterase when alcuronium and atracurium neuromuscular block were antagonized by neostigmine 0.04 and 0.08 mg kg-1 and edrophonium 0.5 and 1.0 mg kg-1. A biexponential relationship was found between the reversal time (time from injection of anticholinesterase to a train-of-four ratio of 70%) and the degree of neuromuscular block at reversal (all groups; F ratio, P less than 0.05). Reversal time was determined by two processes: direct antagonism by the anticholinesterase and spontaneous recovery of the neuromuscular blocking agent, with the latter becoming the major determinant at profound levels of neuromuscular block (0-10% of control twitch height). Neostigmine, in the doses studied, appeared to have a higher "ceiling" of neuromuscular block which it completely antagonized, although edrophonium had a more rapid onset of action. The reversal time for alcuronium became progressively longer relative to atracurium as neuromuscular block increased because of the slower spontaneous recovery rate. Avoidance of profound neuromuscular block at the completion of surgery is required to ensure reliable antagonism of the block within 5-10 min by an anticholinesterase. Neostigmine 0.08 mg kg-1 was found to be the most effective agent in antagonizing profound neuromuscular block.

Atmospheric dry deposition of ions to branches of native Pinus contorta and Pinus monticola (natural surfaces), and nylon filters and Whatman paper filters (surrogate surfaces) were measured in the summer of 1987 in the vicinity of Emerald Lake Watershed (ELW) of the Sequoia National Park located on the western slope of the Sierra Nevada in California. Deposition fluxes of airborne NO−3, NH+4 and SO2−4 to native pines at the ELW were much higher than in the eastern Sierra Nevada, but several times lower than deposition fluxes to natural and surrogate surfaces at the highly polluted site in the San Gabriel Mountains of southern California. Deposition fluxes of NO3− and NH4+ to the natural and surrogate surfaces at the ELW were much higher than deposition of SO42−, providing the importance of N compounds in atmospheric dry deposition in this part of the western U.S. A deficit of inorganic anions in materials deposited to various surfaces indicated a possibility of substantial participation of organic acids in atmospheric dry deposition processes. Nylon and paper filters proved to be poor surrogate surfaces for the estimation of ionic dry deposition to conifer branches.

Twenty patients were given maximal doses of atracurium or vecuronium by infusion during surgery. Anaesthesia was maintained with an infusion of thiopentone, nitrous oxide and fentanyl. In patients administered atracurium, the plasma laudanosine concentration at cessation of surgery was 0.34 (SD 0.22) micrograms ml-1; there was little tendency to cumulate during operation. A 20% higher arterial concentration of thiopentone was found at awakening in patients given atracurium, suggesting CNS stimulation by laudanosine, although the effect is too modest to be of clinical significance.

An air exclusion system was designed, constructed, and tested to determine its effectiveness in studies of air pollutant effects on vegetation. The air exclusion system was shown to be an effective alternative to open-top field chambers for controlled exposures of air pollutants to low growing plants. The system design included particulate and activated charcoal filters, pressure-type blowers, a mixing manifold, and perforated inflatable ducts that were positioned between rows of plants. Tests with CO as a tracer gas indicated optimal system parameters for air exclusion including: air flow of at least 0.944 m³ s⁻¹ within the ducts, three or four rows of holes on the side of each duct pointing 45° upward, 90° to the side, and 45° downward from the center of the duct, four ducts per system, and a hole size that provided an air velocity of 0.5 to 1.8 m s₋₁ over the plant canopy. Reductions of > 70% in ambient O³ concentrations could be achieved over the plant canopy at 0.25 m above the ground with the air exclusion system under optimum conditions (low ambient wind speed and high ambient ozone concentrations). This was comparable to the reductions achieved with either open-top or closed-top chambers. A gradient in ozone concentrations was obtained within a single system by delineating the ducts into three sections with different sized holes. Sulfur dioxide was added to a modified system to provide a gradient of 0, 0.03, 0.07, and 0.15 µL SO₂ L⁻¹ over a winter growing season. No large environmental differences were found between air exclusion systems and open-top chambers vs. outside plots in the summer. In the fall and winter, open-top chambers had higher air, leaf, and soil temperatures than air exclusion sytems or outside plots. Air speed over the plant canopy was higher with the air exclusion system than in open-top chambers or outside plots.

(1987). Technical efficiency relative to a stochastic cost frontier for the England and Wales dairy sector. Oxford Agrarian Studies: Vol. 16, No. 1, pp. 45-55.

In order to assess concentrations and daily patterns of air pollutants at a mountainous site in the South Coast Air Basin, a study was undertaken in the San Dimas Experimental Forest of the San Gabriel Mountains between April 1985 and October 1985. Continuous monitoring of O3, NO, NO2, SO2, total S compounds and light scattering coefficient was conducted. Particulate aerosols were collected twice a week and concentrations of nitrate, ammonium and sulfate in fine ( 2.5 μm diameter) modes were determined. For the June–August period, when the levels of photochemical smog were the highest, monthly 24-h average concentrations of the pollutants were: O3, about 200 μg m−3; NO2, 40–75 μg m−3; NO, 1–5 μg m −3; and SO2, 0.5–5 μgm−3. The concentrations of O3 were about two times higher than in the neighboring stations of the South Coast Air Basin. O3, SO2 and total S concentrations peaked in the early afternoon, generally between 1500 and 1600 PST. Peak concentrations of NO occurred in the morning, generally between 1000 and 1100 PST. NO2 concentrations typically peaked in the late afternoon between 1500 and 1800 PST, but occasionally (in 9 % of days) maximum NO2 occurred in the morning, concurrently with the NO peaks. Daytime concentrations of the nitrate in fine aerosol fraction were generally between 100 and 600 nEq m −3, those of ammonium between 50 and 300 nEq m −3, and concentrations of sulfate between 60 and 250 nEq m−3. A 3-day denuder study showed that HNO3can make up to 73 % of the total amount of total nitrate in the air. NO2 was the most abundant N compound at Tan bark Flat (69–86% of the total amount of the monitored N compounds). Nitrate amounted to 9–15 %, HNO3 to 4–11 %, ammonium to 3–9%, and NO to 1–2% of the total amount of the measured nitrogen compounds.

The purpose of this paper is to reconsider the specification and estimation of agricultural production functions. By assuming a criterion of expected profit maximization and incorporating a management input into the function using dummy variables, least squares estimates of the parameters of the production function are unbiased and consistent. Functions are estimated for four years of annual Farm Management Survey data for the North-West of England. Results presented reveal both reduced marginal productivity estimates and returns-to-scale compared with conventional cross-section estimates.

Three cultivars of rice, Oryza sativa, M7, M9 and S201 were exposed in open-top field chambers to ozone and sulfur dioxide to determine the effects of these important air pollutants on field-grown plants. Exposures were for 15 weeks with ozone at 0, 98, 196, 294 or 392 μg m−3 for 5 h day−1, 5 days week−1, and sulfur dioxide at 131, 262, 393 or 524 μg m−3 for 24 h day−1, 5 days week−1. Three harvests of rice were made after 27 and 68 days and at the end of the exposures. At the first harvest following early plant growth, ozone at the highest concentrations resulted in reductions in growth whereas sulfur dioxide resulted in increased growth. At the second harvest, ozone-exposed plants continued to show reduced growth, whereas sulfur dioxide resulted only in reduced plant height. At the final and major harvest, ozone at 392 μg m−3 reduced total seed weight 12, 29 and 21% in cultivars M7, M9 and S201, respectively. Weight of 100 seeds and straw weight were reduced in M9 and S201 and percent seed sterility in panicles was increased. Ozone reduced height of all cultivars and increased the number of panicles. Sulfur dioxide at 524 μg m−3 reduced total seed weight of M9 and S201 by 22 and 14%, respectively, and weight per hundred seed by 11 and 10%, respectively. The results showed that ozone is much more injurious to rice per unit of pollutant than sulfur dioxide and that reduced yield due to both pollutants was caused mostly by reduced seed size. Increased seed sterility was partially offset by ozone exposure of the plants which produced more panicles. Cultivar M7 was more resistant to ozone or sulfur dioxide than M9 and S201.

Forty-seven species of annual plants from the Mojave Desert were grown in pots and exposed in open-top field chambers located at Riverside, California to test their relative sensitivity to SO/sub 2/ and O/sub 3/. Exposures were 8 h/day for four or five days at 0, 0.05, 0.1, 0.2, 0.3 and 0.4 ppm O/sub 3/ or 0, 0.2, 0.5, 0.6, 0.8, 1.0 and 1.5 ppm SO/sub 2/. Species differed widely in their response to the pollutants. Three species, Camissonia claviformis, Camissonia hirtella and Cryptantha nevadensis, were quite sensitive to both pollutants, exhibiting leaf injury when exposed to 0.1 ppm O/sub 3/ or 0.2 ppm SO/sub 2/. Two species: Festuca octoflora and Lepidium lasiocarpum were tolerant to both pollutants, exhibiting no leaf injury with concentrations of 0.3 ppm O/sub 3/ or 1.5 ppm SO/sub 2/. The other species were intermediate in sensitivity, with O/sub 3/ sensitivity not always corresponding to SO/sub 2/ sensitivity. Total sulfur concentration analysis indicated that for 8 of 11 species tested, plants exposed to 0.2 ppm SO/sub 2/ had a higher sulfur concentration than nonexposed plants. Baileya pleniradiata and Perityle emoryi had the greatest increases in sulfur concentration for exposed versus control plants. To test for effects ofmore » the environmental and exposure system on plant sensitivity, 29 of the species exposed in the open-top chambers were grown in the ground and exposed with a modified chamberless zonal air pollution (ZAP) system to SO/sub 2/ in the Mojave Desert area near Daggett, California. Exposures were for a total of 37 h over six days to 0, 0.4, 0.8 and 1.0 ppm SO/sub 2/ with exposures only during periods with due west winds. Most of the species were not injured with any of the SO/sub 2/ exposure concentrations used with the ZAP system; only Camissonia claviformis showed injury at 0.8 ppm SO/sub 2/ and Oenothera californica exhibited injury at 1.0 ppm SO/sub 2/.« less