Cost of malaria control in China: Henan's consolidation programme from community and government perspectives

Objective To assist with strategic planning for the eradication,of malaria in Henan Province, China, which reached the consolidation phase of malaria control in 1992, when only 318 malaria cases were reported, Methods We conducted a prospective two-year study of the costs for Henan's malaria control programme. We used a cost model that could also be applied to other malaria programmes in-mainland China, and analysed the cost of the three components of Henan's malaria programme. suspected malaria case management,, vector surveillance,,and population blood surveys. Primary cost data were collected from the government, and data on suspected malaria patient's were collected in two malaria counties (population 2 093 100). We enlisted the help of 260 village doctors. in six-townships or former communities (population 247 762), and studied all 12 315 reported cases of suspected malaria in catchment areas in 1994 and 1995. Findings The average-annual government investment in malaria control was estimated to be US$ 111 516 (case-management 59%; active blood surveys 25%;vector surveillance 12%; and contingencies and special projects 4%). The average cost (direct and indirect) for-patients seeking-treatment for suspected malaria was US$ 3.48, equivalent,to 10 days' income for rural residents. Each suspected malaria case cost the government an, average of US$ 0.78. Conclusion Further cuts in government funding will increase future costs, when epidemic malaria returns; investment in malaria control should therefore continue at least at current levels,of US$ 0.03 per person a risk.

Technical, allocative, cost and scale efficiencies in Bangladesh rice cultivation: A non-parametric approach

Applying programming techniques to detailed data for 406 rice farms in 21 villages, for 1997, produces inefficiency measures, which differ substantially from the results of simple yield and unit cost measures. For the Boro (dry) season, mean technical efficiency was efficiency was 56.2 per cent and 69.4 per cent, allocative efficiency was 81.3 per cent, cost efficiency was 56.2 per cent and scale efficiency 94.9 per cent. The Aman (wet) season results are similar, but a few points lower. Allocative inefficiency is due to overuse of labour, suggesting population pressure, and of fertiliser, where recommended rates may warrant revision. Second-stage regressions show that large families are more inefficient, whereas farmers with better access to input markets, and those who do less off-farm work, tend to be more efficient. The information on the sources of inter-farm performance differentials could be used by the extension agents to help inefficient farmers. There is little excuse for such sub-optimal use of survey data, which are often collected at substantial costs.

The efficiency and condition of oysters and macroalgae used as biological filters of shrimp pond effluent

Current shrimp pond management practices generally result in elevated concentrations of nutrients, suspended solids, bacteria and phytoplankton compared with the influent water. Concerns about adverse environmental impacts caused by discharging pond effluent directly into adjacent waterways have prompted the search for cost-effective methods of effluent treatment. One potential method of effluent treatment is the use of ponds or raceways stocked with plants or animals that act as natural biofilters by removing waste nutrients. In addition to improving effluent water quality prior to discharge, the use of natural biofilters provides a method for capturing otherwise wasted nutrients. This study examined the potential of the native oyster, Saccostrea commercialis (Iredale and Roughley) and macroalgae, Gracilaria edulis (Gmelin) Silva to improve effluent water quality from a commercial Penaeus japonicus (Bate) shrimp farm, A system of raceways was constructed to permit recirculation of the effluent through the oysters to maximize the filtration of bacteria, phytoplankton and total suspended solids. A series of experiments was conducted to test the ability of oysters and macroalgae to improve effluent water quality in a flow-through system compared with a recirculating system. In the flow-through system, oysters reduced the concentration of bacteria to 35% of the initial concentration, chlorophyll a to 39%, total particulates (2.28-35.2 mum) to 29%, total nitrogen to 66% and total phosphorus to 56%. Under the recirculating flow regime, the ability of the oysters to improve water quality was significantly enhanced. After four circuits, total bacterial numbers were reduced to 12%, chlorophyll a to 4%, and total suspended solids to 16%. Efforts to increase biofiltration by adding additional layers of oyster trays and macroalgae-filled mesh bags resulted in fouling of the lower layers causing the death of oysters and senescence of macroalgae. Supplementary laboratory experiments were designed to examine the effects of high effluent concentrations of suspended particulates on the growth and condition of oysters and macroalgae. The results demonstrated that high concentrations of particulates inhibited growth and reduced the condition of oysters and macroalgae. Allowing the effluent to settle before biofiltration improved growth and reduced signs of stress in the oysters and macroalgae. A settling time of 6 h reduced particulates to a level that prevented fouling of the oysters and macroalgae.

Effect of water temperature and oxygen levels on the diving behavior of two freshwater turtles: Rheodytes leukops and Emydura macquarii

Rheodytes leukops is a bimodally respiring turtle that extracts oxygen from the water chiefly via two enlarged cloacal bursae that are lined with multi-branching papillae. The diving performance of R. leukops was compared to that of Emydura macquarii, a turtle with a limited ability to acquire aquatic oxygen. The diving performance of the turtles was compared under aquatic anoxia (0 mmHg), hypoxia (80 mmHg) and normoxia (155 mmHg) at 15, 23, and 30degreesC. When averaged across all temperatures the dive duration of R. leukops more than doubled from 22.4 +/- 7.65 min under anoxia to 49.8 +/- 19.29 min under normoxic conditions. In contrast, aquatic oxygen level had no effect on the dive duration of E. macquarii. Dive times for both species were significantly longer at the cooler temperature, and the longest dive recorded for each species was 538 min and 166 min for R. leukops and E. macquarii, respectively. Both species displayed a pattern of many short dives punctuated by occasional long dives irrespective of temperature or oxygen regime. Rheodytes leukops, on average, spent significantly less time (42 +/- 2 sec) at the surface per surfacing event than did E. macquarii (106 +/- 20 sec); however, surface times for both species were not related to either water temperature or oxygen level.

An in situ study of photosynthetic oxygen exchange and electron transport rate in the marine macroalga Ulva lactuca (Chlorophyta)

Direct comparisons between photosynthetic O-2 evolution rate and electron transport rate (ETR) were made in situ over 24 h using the benthic macroalga Ulva lactuca (Chlorophyta), growing and measured at a depth of 1.8 m, where the midday irradiance rose to 400-600 mumol photons m(-2) s(-1). O-2 exchange was measured with a 5-chamber data-logging apparatus and ETR with a submersible pulse amplitude modulated (PAM) fluorometer (Diving-PAM). Steady-state quantum yield ((Fm'-Ft)/Fm') decreased from 0.7 during the morning to 0.45 at midday, followed by some recovery in the late afternoon. At low to medium irradiances (0-300 mumol photons m(-2) s(-1)), there was a significant correlation between O-2 evolution and ETR, but at higher irradiances, ETR continued to increase steadily, while O-2 evolution tended towards an asymptote. However at high irradiance levels (600-1200 mumol photons m-(2) s(-1)) ETR was significantly lowered. Two methods of measuring ETR, based on either diel ambient light levels and fluorescence yields or rapid light curves, gave similar results at low to moderate irradiance levels. Nutrient enrichment (increases in [NO3-], [NH4+] and [HPO42-] of 5- to 15-fold over ambient concentrations) resulted in an increase, within hours, in photosynthetic rates measured by both ETR and O-2 evolution techniques. At low irradiances, approximately 6.5 to 8.2 electrons passed through PS II during the evolution of one molecule of O-2, i.e., up to twice the theoretical minimum number of four. However, in nutrient-enriched treatments this ratio dropped to 5.1. The results indicate that PAM fluorescence can be used as a good indication of the photosynthetic rate only at low to medium irradiances.

High-performance L-band series and parallel switches using low-cost p-i-n diodes

Low-cost UHF-band p-i-n diodes are used to develop high-performance L-band series and parallel switches. To stop the rectification of large RF, signals, the diodes are biased at a large reverse-bias voltage. Parasitic elements of the diodes are tuned out using LC circuits in biasing circuits without increasing the size of the switches. (C) 2002 John Wiley Sons, Inc.

[18O]-Oxygen incorporation reveals novel pathways in spiroacetal biosynthesis by Bactrocera cacuminata and B. cucumis

The origins of the oxygen atoms in 1,7-dioxaspiro[5.5]undecane (1) and hydroxyspiroacetal (2) from Bactrocera cacuminata, and in 2,8-dimethyl-1,7-dioxaspiro[5.5]undecane (3) and hydroxyspiroacetal (4) from B. cucumis, have been investigated by incorporation studies from both [18O2]-dioxygen and [18O]-water. Combined GC-MS examination and high-field NMR analysis have demonstrated that all oxygen atoms in 1 and 2 from B. cacuminata are dioxygen derived, but in contrast, the spiroacetals 3 and 4 from B. cucumis incorporate one ring oxygen from water and one ring oxygen (and the hydroxyl oxygen in 4) from [18O2]-dioxygen. These results reveal not only the generality of monoxygenase mediation of spiroacetal formation in Bactrocera sp., but also an unexpected complexity in their biosynthesis. A general paradigm accommodating these and other observations is presented.

Effect of maternal epidural analgesia on fetal intrapartum oxygen saturation

The use of maternal epidural analgesia in labor may be associated with nonreassuring fetal heart rate (FHR) patterns. Fetal oxygen saturation (FSpO(2)) monitoring may improve assessment of fetal well-being during this time. Mean FSpO(2) values were compared over seven 5-minute epochs: 5 minutes prior to an epidural event (combined insertion of epidural/top-up epidural analgesia and infusion pump bolus), to 30 minutes following the event, including possible effects of maternal position and FHR pattern on FSpO(2) values. Mean FSpO(2) values were significantly different between the 5 minutes prior (49.5%) versus 16-20 minutes (44.3%, p

Are transitions in human gait determined by mechanical, kinetic or energetic factors?

It is currently unclear whether it is the need to maintain metabolic efficiency, the need to keep skeletal loading below critical force levels, or simple mechanical factors that drive the walk-to-run (W R) and run-to-walk (R-W) transitions in human gait. Eighteen adults (9 males and 9 females) locomoted on an instrumented treadmill using their preferred gait. Each completed 2 ascending (W-R) and 2 descending (R-W) series of trials under three levels of loading (0%, 15% and 30% body weight). For each trial, participants locomoted for 60 s at each of 9 different speeds -4 speeds both above and below their preferred transition speed (PTS) plus their PTS. Evidence was sought for critical levels of key kinetic (maximum vertical force, impulse, first peak force, time to first peak force and maximum loading rate), energetic (oxygen consumption, transport cost) and mechanical variables (limb lengths, strength) predictive of the gait transition. Analyses suggested the kinetic variables of time to first peak force and loading rate as the most likely determinants of the W-R and R-W transitions. (C) 2003 Elsevier Science B.V. All rights reserved.

Role of oxygen in the nitrous oxide/carbon reaction

An investigation of the role of oxygen in the nitrous oxide/carbon reaction was carried out on various carbon samples (both graphitic and nongraphitic) over a range of temperatures and partial pressures. Previous work reported that oxygen strongly inhibited the nitrous oxide/carbon reaction. Large ratios of O-2/N2O were used in all previous work. In this work, the O-2/N2O ratio was kept below 1, and we found that oxygen did not inhibit the rate of the C + N2O reaction. Instead, the rate of the reaction in the presence of oxygen was essentially that predicted by the two independent reactions, nitrous oxide/carbon and oxygen/carbon, occurring simultaneously. A simple theoretical explanation is given for the observations, both past and present, on the basis of competitive chemisorption of nitrous oxide and oxygen on active sites.

Cholesterol-lowering therapy with pravastatin in patients with average cholesterol levels and established ischaemic heart disease: is it cost-effective?

Objective: To measure the cost-effectiveness of cholesterol-lowering therapy with pravastatin in patients with established ischaemic heart disease and average baseline cholesterol levels. Design: Prospective economic evaluation within a double-blind randomised trial (Long-Term Intervention with Pravastatin in Ischaemic Disease [LIPID]), in which patients with a history of unstable angina or previous myocardial infarction were randomised to receive 40 mg of pravastatin daily or matching placebo. Patients and setting: 9014 patients aged 35-75 years from 85 centres in Australia and New Zealand, recruited from June 1990 to December 1992. Main outcome measures: Cost per death averted, cost per life-year gained, and cost per quality-adjusted life-year gained, calculated from measures of hospitalisations, medication use, outpatient visits, and quality of life. Results: The LIPID trial showed a 22% relative reduction in all-cause mortality (P < 0.001). Over a mean follow-up of 6 years, hospital admissions for coronary heart disease and coronary revascularisation were reduced by about 20%. Over this period, pravastatin cost $A4913 per patient, but reduced total hospitalisation costs by $A1385 per patient and other long-term medication costs by $A360 per patient. In a subsample of patients, average quality of life was 0.98 (where 0 = dead and 1 = normal good health); the treatment groups were not significantly different. The absolute reduction in all-cause mortality was 3.0% (95% CI, 1.6%-4.4%), and the incremental cost was $3246 per patient, resulting in a cost per life saved of $107730 (95% Cl, $68626-$209881) within the study period. Extrapolating long-term survival from the placebo group, the undiscounted cost per life-year saved was $7695 (and $10 938 with costs and life-years discounted at an annual rate of 5%). Conclusions: Pravastatin therapy for patients with a history of myocardial infarction or unstable angina and average cholesterol levels reduces all-cause mortality and appears cost effective compared with accepted treatments in high-income countries.