The treatment of run-off from a fertiliser plant for nitrification, denitrification and phosphorus removal by use of constructed wetlands: a demonstration study

The paper describes an evaluation carried out on demonstration scale to show that it was possible to use a Hybrid Reed Bed System comprising a Horizontal flow and a Vertical Flow Bed for treating the high strength run-off from a fertiliser packaging plant. The site is located close to an estuary which is sensitive to nutrients. The environmental regulators were therefore concerned that excessive mass flows of nitrate, ammoniacal nitrogen and phosphate, potentially arising from the site run-off, were not discharged into the estuary. The fertiliser manufacturing company required a simple, low maintenance system for removing nitrogen and phosphorus. A series of experimental runs were carried out to characterise the performance of the Hybrid System, establishing the effluent quality that could be achieved and the mass removal rate which was appropriate for acceptable treatment. These tests showed that it was possible to achieve a reduction of 79% in Total N whilst using molasses as a carbon source for denitrification. When using a 4:1 recycle ratio this produced an effluent with concentrations of 14 mg NH(4)-N/litre and 18 mg NO(3)-N/litre from treating site run-off containing concentrations in the order of 75 mg/litre of both NH(3)N and NO(3)-N. Chemical dosing with an iron salt brought the P concentration down to around 0.5 mg PO(4)-P/litre.

Dental care use: does dental insurance truly make a difference in the US?

OBJECTIVE

Having medical insurance with or without coverage for dental care has been shown to be associated with an increase in dental use. The purpose of this study is to provide information that will help describe this behavior.

METHOD

We isolate the independent effect of health insurance on the likelihood of a dental visit by analyzing Medical Expenditure Panel Survey (MEPS) data.

RESULTS

Data show that persons with private medical coverage, controlling for dental coverage and other socioeconomic and demographic factors, are more likely to have a dental visit than persons without private medical coverage. Having medical insurance with or without coverage for dental care is associated with an increased likelihood of having a dental visit. These data suggest a more complex role for dental insurance beyond that of traditional insurance motivation.

CONCLUSIONS

These data suggest that programmes designed to improve dental access with added dental coverage may not be sufficient to remedy access deficiencies and may offer only modest extra incentives to use dental services over and above medical insurance.

Employer contribution methods and health insurance premiums: does managed competition work?

We derive a two-stage model in which health plans first compete to be selected by employers and subsequently compete to be chosen by employees. We identify the key determinants of competition and show that increasing competition at one stage often comes at the expense of competition at the other stage. Many economists and policymakers have argued that in order to increase competition among health plans, employers should offer multiple plans and structure premium contributions to make employees more price sensitive. While our theoretical model shows that following this policy prescription may not actually lead to lower premiums, our empirical analysis provides some support for this recommendation. We also find that if employers instead pay the full premium, premiums increase when they offer additional plans. These results have important implications for both employers and policymakers.

Assessing the impact of health plan choice

Many health policy researchers have argued that increased insurance plan choice will enhance the efficiency of the health care system. However, relatively little is known about plan choice and its association with insurance coverage and access to and satisfaction with health care. Using data from the 1996 Medical Expenditure Panel Survey, we find that 55 percent of workers had plan choice in that year. Approximately 26 percent of workers with choice obtained it through a family member. Controlling for other factors, plan choice is associated with higher levels of employment-based insurance coverage and a greater likelihood that workers are satisfied that their families' health care needs are being met.

The case of disability in the family: impact on health care utilization and expenditures for nondisabled members

Families with a disabled member undergo heightened emotional and financial stress, which can arise from caring for the person with one or more disabilities over the life course or at the end of life. Because health care resources are strained by the needs of the disabled family member, nondisabled members are often limited in health care access and utilization when they are most in need of care. This analysis uses the National Medical Expenditure Survey to describe families with disabled members, based on multiple definitions of disability, and to examine health care utilization and expenditures by nondisabled family members. Indications of higher use of medical care by adult, nondisabled members of such families support the frequent reports in the literature of stress occurring in these situations. The signals of a household rationing effect for families near and at poverty levels should alert policy makers to consider the needs of the whole family when creating or modifying assistance programs.

The Cognitive Failures Questionnaire (CFQ) and its correlates

This paper describes a questionnaire measure of self-reported failures in perception, memory, and motor function. Responses to all questions tend to be positively correlated, and the whole questionnaire correlates with other recent measures of self-reported deficit in memory, absent-mindedness, or slips of action. The questionnaire is however only weakly correlated with indices of social desirability set or of neuroticism. It is significantly correlated with ratings of the respondent by his or her spouse, and accordingly does have some external significance rather than purely private opinion of the self. The score is reasonably stable over long periods, to about the same extent as traditional measures of trait rather than state. Furthermore, it has not thus far been found to change in persons exposed to life-stresses. However, it does frequently correlate with the number of current psychiatric symptoms reported by the same person on the MHQ; and in one study it has been found that CFQ predicts subsequent MHQ in persons who work at a stressful job in the interval. It does not do so in those who work in a less stressful environment. The most plausible view is that cognitive failure makes a person vulnerable to showing bad effects of stress, rather than itself resulting from stress.

The Cognitive Failures Questionnaire (CFQ) and its correlates

This paper describes a questionnaire measure of self-reported failures in perception, memory, and motor function. Responses to all questions tend to be positively correlated, and the whole questionnaire correlates with other recent measures of self-reported deficit in memory, absent-mindedness, or slips of action. The questionnaire is however only weakly correlated with indices of social desirability set or of neuroticism. It is significantly correlated with ratings of the respondent by his or her spouse, and accordingly does have some external significance rather than purely private opinion of the self. The score is reasonably stable over long periods, to about the same extent as traditional measures of trait rather than state. Furthermore, it has not thus far been found to change in persons exposed to life-stresses. However, it does frequently correlate with the number of current psychiatric symptoms reported by the same person on the MHQ; and in one study it has been found that CFQ predicts subsequent MHQ in persons who work at a stressful job in the interval. It does not do so in those who work in a less stressful environment. The most plausible view is that cognitive failure makes a person vulnerable to showing bad effects of stress, rather than itself resulting from stress.

Distractibility and memory deficits in long-term survivors of acute lymphoblastic leukemia

A comprehensive neuropsychological test battery was administered to 37 long-term survivors of acute lymphoblastic leukemia and 18 newly diagnosed acute lymphoblastic leukemia patients in an attempt to identify patterns of neuropsychological performance. Newly diagnosed patients between 7 and 15 years of age generally obtained scores within normal limits. On most measures of intelligence long-term survivors within the same age range obtained mean test scores approximately 1 standard deviation below the population mean. Fourteen of 30 long-term survivors under 16 years of age exhibited a pattern of test scores suggestive of memory deficits and distractibility which may have interfered with academic achievement. Only one patient over 8 years of age at diagnosis produced a similar pattern of scores. We conclude that young children treated for acute lymphoblastic leukemia are at risk for the development of neuropsychological dysfunction and that appropriate programs for identification and academic remediation should be instituted.

Protein-binding of small molecules: new gel filtration method

The use of frontal analysis chromatography on Sephadex columns, previously described for protein-protein interactions (Nichol & Winzor, 1964) has been extended to the treatment of protein-small molecule interaction. Chromatograms obtained with bovine serum albumin and three different sulphonamides (sulphanilamide, sulphapyridine and sulphamethoxypyridazine) were found to conform to the theoretical patterns, and the values for the fraction of drug bound were in good agreement with those obtained by equilibrium dialysis.