Different Levels Of Treatment Research Articles

A Nonparametric Bayesian Model for Inference in Related Longitudinal Studies

Summary We discuss a method for combining different but related longitudinal studies to improve predictive precision. The motivation is to borrow strength across clinical studies in which the same measurements are collected at different frequencies. Key features of the data are heterogeneous populations and an unbalanced design across three studies of interest. The first two studies are phase I studies with very detailed observations on a relatively small number of patients. The third study is a large phase III study with over 1500 enrolled patients, but with relatively few measurements on each patient. Patients receive different doses of several drugs in the studies, with the phase III study containing significantly less toxic treatments. Thus, the main challenges for the analysis are to accommodate heterogeneous population distributions and to formalize borrowing strength across the studies and across the various treatment levels. We describe a hierarchical extension over suitable semiparametric longitudinal data models to achieve the inferential goal. A nonparametric random-effects model accommodates the heterogeneity of the population of patients. A hierarchical extension allows borrowing strength across different studies and different levels of treatment by introducing dependence across these nonparametric random-effects distributions. Dependence is introduced by building an analysis of variance (ANOVA) like structure over the random-effects distributions for different studies and treatment combinations. Model structure and parameter interpretation are similar to standard ANOVA models. Instead of the unknown normal means as in standard ANOVA models, however, the basic objects of inference are random distributions, namely the unknown population distributions under each study. The analysis is based on a mixture of Dirichlet processes model as the underlying semiparametric model.

Primary HIV infection as source of HIV transmission within steady and casual partnerships among homosexual men.

To assess the contribution of primary or acute HIV infection to the transmission of HIV among homosexual men in Amsterdam and to investigate how the initiation of treatment during primary HIV infection (PHI) can affect the incidence of HIV infection. A mathematical model describing HIV transmission among homosexual men was developed. In the model, men are involved in both steady and casual partnerships. Infectivity is higher during PHI than during chronic HIV infection. Highly active antiretroviral therapy reduces infectivity and increases the time to the development of AIDS. Its effect is enhanced if treatment is initiated during PHI. HIV incidence and the fraction of transmission attributed to PHI were calculated for different levels of treatment efficacy. Primary infections account for 35% of HIV transmissions from casual partners and 6% of transmissions from steady partners. Among all new infections, only 11% occurs during PHI. Therefore, the effect of treatment during PHI on the incidence of HIV is limited. However, in a community with higher risky behaviour among casual partners, the fraction of transmission attributed to PHI increases to 25%. Primary infections play a more important role in transmission from casual partners than in transmission from steady partners. Therefore, in communities in which steady partners account for the majority of new infections and the epidemic is at an advanced phase, the contribution of PHI to the transmission of HIV is rather small and the effect of early treatment on the incidence of HIV is limited.

Partner Assaultive Men and the Stages and Processes of Change

Researchers have recently suggested that the Transtheoretical Model of behavior change (TTM; Prochaska, J. O. DiClemente, C. C., and Norcross, J. C., 1992, Am. Psychol. 47: 1102–1114) might help in understanding the mechanisms through which partner assaultive men attempt to change their abusive behavior. In the present study, we present data from 2 psychometrically sound scales designed to assess the stages and processes of change in a cross-sectional sample of 250 men attending 2 batterer's intervention and prevention programs: the University of Rhode Island Change Assessment Scale for Domestic Violence (URICA-DV; Levesque, D. A., Gelles, R. J., and Velicer, W. F., 2000, Cog. Therapy Res. 24: 175–200), which assesses movement through the stages of change, and the Processes of Change Scale (POC), developed by the authors to assess self-reported usage of behavior change processes. Cross-validated cluster analyses indicated a three-cluster solution based upon URICA-DV scores: Immotive, Unprepared Action, and Preparticipation. Results indicated that individuals in more advanced stages of change reported using more behavior change processes, although this did not appear to result from being in treatment for a longer period of time. These data are interpreted in light of recent data indicating relatively small effect sizes for batterer's treatment programs and how assessment of the stages and processes of change might assist in matching men to different levels of treatment.

The effects of sewage discharge on water quality and phytoplankton of Hawai'ian coastal waters

The effects of sewage discharge on algal populations and the quality of Hawai'ian coastal waters were investigated. Two outfalls were studied. One discharges primary treated sewage and the other discharges secondary treated sewage but are otherwise similar. This enabled comparisons of the effects of these different levels of treatment on the water quality and algal productivity of receiving waters. Plumes were followed and repeatedly sampled in a time-series manner. Rhodamine dye was used as a conservative tracer to compare the dilution behavior of the plume constituents MRP, NO 3+NO 2, NH 4, Silicate, TDP, TDN, total bacteria, PC, and PN. Rates of initial dilution ranged from two to almost three orders of magnitude, and were in reasonable agreement with engineering model predictions. Dilution of plume constituents approximated that of Rhodamine until background concentrations were reached, typically within 10 min of discharge. Chl a concentrations did not increase through time in the primary sewage plume but did increase up to 30% in the secondary sewage plume. However, rates of far-field dilution were so rapid that the increase could not have been due to algal growth. The increase was attributed to the plume mixing with a water mass whose relative chl a concentrations were greater. Rates of secondary dilution ranged from 2 to 3 orders of magnitude resulting in total dilutions of 10 5–10 6 within 3 h of discharge. These rates of secondary dilution were much greater than model predictions. From a nutrient standpoint, secondary treatment exhibited no advantages over primary treatment because dilutions were so rapid.

Assessing airborne biological hazard from urban wastewater treatment

The production of microbial aerosols by urban sewage treatment plants may have wide hygienic implications which call for careful evaluation: exposure to such aerosols may in fact represent a health hazard for plant workers and nearby residents alike. This paper describes the results of a study analysing the degree of microbial contamination at different levels of treatment at several plants in the City of Leghorn (Livorno, Italy). Monthly aerosol samples were collected with an agar impact sampler from January to November 1996, from different sites at an activated sludge plant, an anaerobic sludge plant and a wastewater washing station. The total bacterial and coliform counts were determined, and pathogenic enteric bacteria and viruses were determined. These same parameters were also measured in wastewater and sludge samples obtained at the same sites. The results revealed that high-grade airborne contamination existed at several of the studied sites. In particular, pathogenic enteric bacteria ( Salmonella enteritidis and S. boydii) were isolated in 2% of the samples (540 l per sample), reovirus in 46% and enterovirus in 9% (1800 litres per sample in indoor environment and 3000 l outdoor), always in association with the former virus. The biological parameters measured had no evident correlation with meteorological factors such as temperature, relative humidity or wind characteristics. Viral contamination proved to be quite wide-spread and detectable even in the presence of low levels of bacterial contamination. Although virological analysis have been only qualitative, and the different volumes examined for viruses and bacteria cannot allow us to appraise with accuracy the association between these two parameters, the viral presence along with low bacteria contamination suggests more dedicated studies to address with greater accuracy the quantitative aspects of this association. However the monitoring performed allowed for a determination of the areas of greatest potential risk for plant workers, and the preventive measures most suitable to guaranteeing their safety.

Uncertainties in risk analysis: Six levels of treatment

This paper examines different levels of analytical sophistication in the treatment of uncertainties in risk analysis, and the possibility of transfer of experience across fields of application. First, this paper describes deterministic and probabilistic methods of treatment of risk and uncertainties, and the different viewpoints that shape these analyses. Second, six different levels of treatment of uncertainty are presented and discussed in the light of the evolution of the risk management philosophy in the US. Because an in-depth treatment of uncertainties can be complex and costly, this paper then discusses when and why a full (two-tier) uncertainty analysis is justified. In the treatment of epistemic uncertainty, an unavoidable and difficult problem is the encoding of probability distributions based on scientific evidence and expert judgments. The last sections include a description of different approaches to the aggregation of expert opinions and their use in risk analysis, and a recent example of methodology and application (in seismic hazard analysis) that can be transferred to other domains.

A revision of the British elms (Ulmus L., Ulmaceae): the historical background

Abstract The British elms have historically proven to be recalcitrant taxonomically, with at least six different levels of treatment being applied. The taxonomic history of the group and the nomenclature is outlined from the ancient authors up until the present day. This paper is the foundation for future articles in which a novel taxonomic treatment is introduced.

Exploring Repunits

This article describes a discovery activity which is organized and developed at two different levels of treatment corresponding to the different degree of mathematical maturity of students. Using an 8‐digit calculator, students at the first level (7‐9th graders) explore patterns which lead them to discover the properties of repunits and their relationships to many mathematical curiosities. At the second level (10‐12th graders) students may be interested in further extension exploring why these patterns emerge and offering algebraic justification.

Functional status, referral and cost of treatment for persons with traumatic head injury

This study was conducted to examine functional status, costs of treatment, and how function and costs are related to the referral process of persons with traumatic head injury (THI). The study attempted to answer questions such as: what portion of the THI population is not referred on for subsequent treatment? Is referral dependent upon level of function at time of discharge from acute care? What are the costs associated with different levels of treatment by different facilities? Information was gathered from medical record reviews. Data were gathered from 101 persons with traumatic head injury (PWTHI) using a survey form, a functional assessment inventory, and a performance status scale. Per subject cost statements were obtained from the treatment/service facilities. Results indicate that the factors in the referral process for further treatment and rehabilitation do not appear to be consistent. Acute care referral at discharge is dependent upon severity of residual dysfunction including other factors than THI, while referral at discharge from a rehabilitation centre is dependent upon less obvious factors; one of which may be age at time of injury. Acute care and rehabilitation centre per patient average costs are quite similar and significantly higher than average per client costs.

The effect of water treatment on the speciation and concentration of lead in domestic tap water derived from a soft upland source

Thirty-minute stagnation tapwater samples were collected from five households with lead plumbing near Glasgow, Scotland. Four sites were supplied with water from the same source, but subject to different levels of treatment ranging from no treatment whatever at one extreme, to coagulation, filtration, chlorination and pH adjustment at the other. Water treatment processes greatly reduce the plumbosolvent properties of the water as indicated by 30 min stagnation, and it is postulated that the removal of colloidal hydrous iron oxide/humic acid species is particularly important in this regard. The presence of appreciable levels of colloidal aluminium in some alum-coagulated water samples does not appear to influence plumbosolvency.

Electron correlation and basis set effects in unimolecular reactions. A study of the model rearrangement system N2H2

As a model for simple 1, 2 shift rearrangements, N2H2 has been studied with ab initio wave functions at several levels of theory. Equilibrium structures for aminonitrene, trans-diimide, and cis-diimide and transition state structures for the two rearrangement reactions that interconvert the isomers were carefully determined so as to isolate basis set and electron correlation effects on the structure predictions. An examination of the changes in the calculated electron density between wave functions from different levels of treatment is presented. The self-consistent electron pairs (SCEP) method was used to handle the large correlated wave functions obtained in this study. With the largest basis set (TZ+2P) used, and with SCEP wave functions spanning a space of up to 176 000 configurations, the following energies relative to trans-diimide were found: 7.2 kcal for cis-diimide, 55.1 kcal for the trans to cis-diimide barrier, 24.5 kcal for aminonitrene, and 82.6 kcal for the trans-diimide to aminonitrene barrier. The system was found to be planar in all structures.

Development of effluent guidelines and Environmental Protection Agency research and development program for edible oils industry.

AbstractThis paper describes the statutory basis for the establishment of effluent limitations guidelines and standards of performance for this industry including remarks on water quality standards. The Environmental Protection Agency’s research, development, and demonstration program is presented. The specific objectives, solution required, activities, and best available treatment, zero discharge concept, and total elimination of discharges (elimination of multi‐media pollution discharges) are discussed. The synopsis of two Environmental Protection Agency‐industry sponsored demonstration grants is presented. The seven most frequently asked questions and their answers regarding the water pollution control act also are introduced. The Federal Water Pollution Control Act of 1972 directed that the U.S. embark upon major new efforts for controlling pollution at its source. The new Act provides for uniform effluent limitations for industrial categories and achievement dates. Congress set two interim dates of July 1, 1977, and July 1, 1983, by which different levels of treatment are to be reached. It is a timetable based upon advances in technology. For all dischargers, other then publicly owned treatment works, not later than July 1, 1977, effluent limitations are to be achieved which represent the application of the “best practicable control technology currently available.” At the same time, all publicly owned waste treatment facilities must utilize “secondary treatment,” and, if an industrial discharger sends its wastes through a publicly owned treatment works, certain “pretreatment standards” must be met. An additional requirement is that by the July 1977 date, effluent limitations may be imposed so that any state law will be met. Not later than July 1, 1983, effluent requirements must be met which represent the “best available technology economically achievable” and for publicly owned waste treatment facilities which represent the application of the “best practicable waste treatment technology.” Any other applicable pretreatment standards also must be attained by that date. Special standards for toxic substances also must be observed from that date of promulgation of regulations covering such substances.

Use of Damping Materials for Noise Reduction on Railway Carriages and Other Equipment

Noise-level measurements are described that were carried out on a British Railway's buffet car both untreated and with two different levels of treatment. The whole carriage, walls, floor, and roof were sprayed with a high-efficiency vibration-damping material that reduced the noise over the whole frequency spectrum. There was also high-frequency airborne noise coming up through the floor, which required a separate treatment. The average drop was 7 dB. Possible alternative damping systems and alternative methods of application, such as preformed heat-fusible damping sheets, are discussed. Noise-level measurements are also described for the driver's cab of a diesel locomotive and for domestic equipment, such as washing-machine spin driers.