Treatment of pulp and paper industry bleaching effluent by electrocoagulant process.

The experiments were carried out in an electrocoagulation reactor with aluminum as sacrificial electrodes. The influence of electrolysis time, current density, pH, NaCl concentration, rotational speed of the stirrer and electrode distance on reduction of color, COD and BOD were studied in detail. From the experimental results, 15 mA/cm(2) current density, pH of 7, 1 g/l NaCl, 100 rpm, 28°C temperature and 3 cm electrode distance were found to be optimum for maximum reduction of color, COD and BOD. The reduction of color, COD and BOD under the optimum condition were found to be 94%, 90% and 87% respectively. The electrode energy consumption was calculated and found to be varied from 10.1 to 12.9 kWh/m(3) depending on the operating conditions. Under optimal operating condition such as 15 mA/cm(2) current density, pH of 7, 1 g/l NaCl, 100 rpm, 28°C temperature and 3 cm electrode distance, the operating cost was found to be 1.56 US $/m(3). The experimental results proved that the electrocoagulation is a suitable method for treating bleaching plant effluents for reuse.

CMap 1.01: a comparative mapping application for the Internet.

UNLABELLED: CMap is a web-based tool for displaying and comparing maps of any type and from any species. A user can compare an unlimited number of maps, view pair-wise comparisons of known correspondences, and search for maps or for features by name, species, type and accession. CMap is freely available, can run on a variety of database engines and uses only free and open software components. AVAILABILITY: http://www.gmod.org/cmap

Batch adsorption studies for chromium removal.

The adsorption of hexavalent chromium (Cr (VI)) on pongamia (Pongamia pinnata) leaf powder was investigated in the present study. Crude pongamia leaf powder (CPLP) and nitric acid treated pongamia leaf powder (APLP) were used as adsorbents. CPLP did not show remarkable adsorption efficiency but APLP had good adsorption capacity and adsorption removal efficiency. The parameters studied included the contact time, initial solute concentration and pH. The optimum pH for removal of chromium was found to be 2 for both CPLP and APLP. The best contact time for maximum chromium adsorption was 165 minutes for CPLP and APLP. CPLP and APLP showed good adsorption capacity and adsorption removal efficiency at an initial chromium concentration of 5 mg/L. The adsorption was found to follow Langmuir and Freundlich isotherms for CPLP and APLP but they showed good curve fit for Freundlich isotherm.

Quality assessments of HMO diagnosis databases used to monitor childhood vaccine safety.

OBJECTIVE: To assess the quality of automated diagnoses extracted from medical care databases by the Vaccine Safety Datalink (VSD) study. METHODS: Two methods are used to assess quality of VSD diagnosis data. The first method compares common automated and abstracted diagnostic categories ("outcomes") in 1-2% simple random samples of study populations. The second method estimates positive predictive values of automated diagnosis codes used to identify potential cases of rare conditions (e.g., acute ataxia) for inclusion in nested case-control medical record abstraction studies. RESULTS: There was good agreement (64-68%) between automated and abstracted outcomes in the 1-2% simple random samples at 3 of the 4 VSD sites and poor agreement (44%) at 1 site. Overall at 3 sites, 56% of children with automated cerebella ataxia codes (ICD-9 = 334) and 22% with "lack of coordination" codes (ICD-9 = 781.3) met objective clinical criteria for acute ataxia. CONCLUSIONS: The misclassification error rates for automated screening outcomes substantially reduce the power of screening analyses and limit usefulness of screening analyses to moderate to strong vaccine-outcome associations. Medical record verification of outcomes is needed for definitive assessments.

A graph-theoretic approach to comparing and integrating genetic, physical and sequence-based maps.

For many species, multiple maps are available, often constructed independently by different research groups using different sets of markers and different source material. Integration of these maps provides a higher density of markers and greater genome coverage than is possible using a single study. In this article, we describe a novel approach to comparing and integrating maps by using abstract graphs. A map is modeled as a directed graph in which nodes represent mapped markers and edges define the order of adjacent markers. Independently constructed graphs representing corresponding maps from different studies are merged on the basis of their common loci. Absence of a path between two nodes indicates that their order is undetermined. A cycle indicates inconsistency among the mapping studies with regard to the order of the loci involved. The integrated graph thus produced represents a complete picture of all of the mapping studies that comprise it, including all of the ambiguities and inconsistencies among them. The objective of this representation is to guide additional research aimed at interpreting these ambiguities and inconsistencies in locus order rather than presenting a "consensus order" that ignores these problems.

Gramene, a tool for grass genomics.

Gramene (http://www.gramene.org) is a comparative genome mapping database for grasses and a community resource for rice (Oryza sativa). It combines a semi-automatically generated database of cereal genomic and expressed sequence tag sequences, genetic maps, map relations, and publications, with a curated database of rice mutants (genes and alleles), molecular markers, and proteins. Gramene curators read and extract detailed information from published sources, summarize that information in a structured format, and establish links to related objects both inside and outside the database, providing seamless connections between independent sources of information. Genetic, physical, and sequence-based maps of rice serve as the fundamental organizing units and provide a common denominator for moving across species and genera within the grass family. Comparative maps of rice, maize (Zea mays), sorghum (Sorghum bicolor), barley (Hordeum vulgare), wheat (Triticum aestivum), and oat (Avena sativa) are anchored by a set of curated correspondences. In addition to sequence-based mappings found in comparative maps and rice genome displays, Gramene makes extensive use of controlled vocabularies to describe specific biological attributes in ways that permit users to query those domains and make comparisons across taxonomic groups. Proteins are annotated for functional significance using gene ontology terms that have been adopted by numerous model species databases. Genetic variants including phenotypes are annotated using plant ontology terms common to all plants and trait ontology terms that are specific to rice. In this paper, we present a brief overview of the search tools available to the plant research community in Gramene.

The risk of seizures after receipt of whole-cell pertussis or measles, mumps, and rubella vaccine.

BACKGROUND: The administration of the diphtheria and tetanus toxoids and whole-cell pertussis (DTP) vaccine and measles, mumps, and rubella (MMR) vaccine has been associated with adverse neurologic events, including seizures. We studied the relation between these vaccinations and the risk of a first seizure, subsequent seizures, and neurodevelopmental disability in children. METHODS: This cohort study was conducted at four large health maintenance organizations and included reviews of the medical records of children with seizures. We calculated the relative risks of febrile and nonfebrile seizures among 679,942 children after 340,386 vaccinations with DTP vaccine, 137,457 vaccinations with MMR vaccine, or no recent vaccination. Children who had febrile seizures after vaccination were followed to identify the risk of subsequent seizures and other neurologic disabilities. RESULTS: Receipt of DTP vaccine was associated with an increased risk of febrile seizures only on the day of vaccination (adjusted relative risk, 5.70; 95 percent confidence interval, 1.98 to 16.42). Receipt of MMR vaccine was associated with an increased risk of febrile seizures 8 to 14 days after vaccination (relative risk, 2.83; 95 percent confidence interval, 1.44 to 5.55). Neither vaccination was associated with an increased risk of nonfebrile seizures. Analyses of automated data alone gave results similar to the analyses of the data from medical-record reviews. The number of febrile seizures attributable to the administration of DTP and MMR vaccines was estimated to be 6 to 9 and 25 to 34 per 100,000 children, respectively. As compared with other children with febrile seizures that were not associated with vaccination, the children who had febrile seizures after vaccination were not found to be at higher risk for subsequent seizures or neurodevelopmental disabilities. CONCLUSIONS: There are significantly elevated risks of febrile seizures on the day of receipt of DTP vaccine and 8 to 14 days after the receipt of MMR vaccine, but these risks do not appear to be associated with any long-term, adverse consequences.

Quality of HMO vaccination databases used to monitor childhood vaccine safety. Vaccine Safety DataLink Team.

The availability of large, population-based, automated, medical care databases provides unique opportunities for monitoring the safety of childhood vaccines. The authors assessed the quality of automated vaccination databases by comparing them with vaccinations documented in paper-based medical records at three large US West Coast health maintenance organizations (HMOs) participating in the Vaccine Safety DataLink (VSD) study, a Centers for Disease Control and Prevention collaborative study of childhood vaccine safety. The authors randomly selected 1% or 2% samples of VSD study populations (n = 1,224-2,577) for data quality analyses. Agreement between automated and abstracted vaccinations required identical triads of child identification number, vaccination date, and vaccine type. Separate analyses were conducted for each HMO and for each vaccine type administered between 1991 and 1995. Agreement was measured by three matching proportions: 1) the proportion of automated vaccinations present in the abstracted source, 2) the proportion of abstracted vaccinations present in the automated source, and 3) the proportion of vaccinations from either source present in both sources. Overall, for common childhood vaccines, proportion 1 ranged from 83% to 99%, proportion 2 ranged from 82% to 98%, and proportion 3 ranged from 70% to 97%. Lack of automated data was the most frequent type of discrepancy, followed by date mismatches and vaccine type mismatches. Vaccination exposure classification errors in the range reported here were found by mathematical modeling to only modestly bias measured medical outcome rate ratios toward the null hypothesis. The results of the data quality analyses support the usefulness of vaccination exposure data derived from these automated HMO vaccination databases.

A population-based case-cohort evaluation of the efficacy of mammographic screening for breast cancer.

Screening efficacy may be evaluated in population-based, observational studies, provided one addresses biases that arise in nonrandomized screening evaluations. The authors evaluated the association of mammographic screening with breast cancer mortality among women without prevalent breast cancer. The cohort consisted of 94,656 women, aged > or = 40 years, enrolled in a large health maintenance organization in Washington State during the period 1982-1988. A case-cohort design limited chart abstraction of risk factor and screening information to 4% of the cohort. There were 1,144 incident breast cancer cases, including 126 who died of breast cancer during the study interval. An age-stratified proportional hazards analysis compared the screening experience of the breast cancer deaths with that of 2,237 controls. The family history of breast cancer, previous biopsy, and parity were included in the model to control for potential confounding effects of selection bias. With a mean follow-up of only 3.5 years postscreening, there was a small but statistically nonsignificant reduction in the risk of breast cancer mortality among women screened 1 year prior to diagnosis compared with unscreened women. The relative risk was 0.80 (95% confidence interval 0.34-1.85) for women aged > or = 40 years and 0.61 (95% confidence interval 0.23-1.62) for women aged > or = 50 years. This paper illustrates how case-cohort methodology can be used to perform efficient assessment of screening efficacy in large cohorts, while eliminating or controlling for sources of bias.

Development and validation of an immunization tracking system in a large health maintenance organization.

Practitioners seeing individual patients and those charged with improving immunization practices in that population need accurate information on the epidemiology of immunizations within the population. To meet this need, we have developed a computer-based record of data required by the National Childhood Vaccine Injury Act of 1986 for all immunizations given to 350,000 enrollees in a large health maintenance organization. In the first eight months of operation, 102,271 immunizations representing 11 separate antigens given to 65,676 enrollees were entered into the database. Comparison of immunizations given and recorded in the medical record with the database shows that the system has high sensitivity, specificity, and positive predictive value, but a relatively low negative predictive value. The database is being used for analysis of current immunization practices for Haemophilus influenzae b vaccine and for research on adverse outcomes of childhood immunizations.

Development of an immunization tracking system in a large health maintenance organization. Group Health Cooperative of Puget Sound.

We have successfully developed a mainframe system for tracking all immunizations administered to enrollees in a large HMO. This system will provide comprehensive immunization records on a population of over 350,000 patients. Data required by the National Childhood Vaccine Injury Act of 1986 are locally entered into terminals, and records of immunization are stored in a database. Preliminary results show that data entry times are practical, but that improvement in data quality is needed. This immunization tracking system will be used for research, and as the foundation of an immunization reminder system under development.

Revisions in the risk-based Breast Cancer Screening Program at Group Health Cooperative.

To pursue the goal of achieving regular use of mammography in women 40 years of age and older, a risk-based selective approach to screening was implemented at a 400,000-member managed health care system in the Northwest in 1985. This article describes the context for this approach to selective screening and reviews revisions in the algorithm used to determine when and how a woman should be screened. Changes made in 1988 with respect to age criteria, intervals for mammography, and which risk factors to include are discussed. The result of these changes is that 83% of women 40 years of age and older are now eligible for regular mammography compared with 57% under the former system. The total use of mammography in any given year remains unchanged. The results of this analysis have implications for other organizations attempting to promote the use of mammography.

Rapid estimation of hospitalization charges from a brief medical record review. Evaluation of a multivariate prediction model.

In settings where an itemized hospital bill is not generated, estimation of hospitalization charges for research or administrative purposes can be a laborious task. This article examines the extent to which the number of hospital days spent outside an intensive care unit (ICU), number of days in an ICU, number of laboratory tests performed, number of x-rays, and number of surgeries can be used in a multiple regression equation to impute inpatient charges for a sample of 103 hospitalizations at a Veterans Administration hospital. These predictor variables, all of which are readily ascertained in a brief medical record review, accounted for about 97% of the variance in imputed hospital charges. The bootstrap method was applied for validation of the prediction equation. Application of the method described here may be of value to researchers concerned with hospital charge estimation in non-fee-for-service settings.