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PubMed2005

In-vessel composting of household wastes.

The process of composting has been studied using five different types of reactors, each simulating a different condition for the formation of compost; one of which was designed as a dynamic complete-mix type household compost reactor. A lab-scale study was conducted first using the compost accelerators culture (Trichoderma viridae, Trichoderma harzianum, Trichorus spirallis, Aspergillus sp., Paecilomyces fusisporus, Chaetomium globosum) grown on jowar (Sorghum vulgare) grains as the inoculum mixed with cow-dung slurry, and then by using the mulch/compost formed in the respective reactors as the inoculum. The reactors were loaded with raw as well as cooked vegetable waste for a period of 4 weeks and then the mulch formed was allowed to maturate. The mulch was analysed at various stages for the compost and other environmental parameters. The compost from the designed aerobic reactor provides good humus to build up a poor physical soil and some basic plant nutrients. This proves to be an efficient, eco-friendly, cost-effective, and nuisance-free solution for the management of household solid wastes.

Bioreactors↗
PubMed2001

A therapeutic vaccine for mucosal candidiasis.

Persistent and recurrent infection of mucosal surfaces with Candida albicans is common, ranging from a nuisance to a life threatening clinical problem. No effective prophylactic or therapeutic vaccine has been developed. We have studied a mouse model of oral candida infection to identify regulatory and effector molecules of T cell activation as parameters of induced immunity, and here describe the use of this model to determine an optimal immunisation strategy. Oral immunisation with the blastospore yeast form (but not subcutaneous immunisation) induced clinical immunity, with a shift in parameters of cytokine response characterised by an early and sustained production of both IFN-gamma and IL-4 from antigen-stimulated cervical node T lymphocytes.

Animals↗
PubMed1995

Laboratory medicine parameter. Utilizing monospecific antihuman globulin to test blood-group compatibility.

When using polyspecific antihuman globulin (AHG) reagents to detect unexpected antibodies or for crossmatching, reactivity in the AHG phase may be due exclusively to the AHG anticomplement component. A lengthy evaluation may be needed to prove that the reactivity is caused by a "nuisance" antibody, one that is clinically insignificant. Clinically significant transfusion intolerance is rare when caused by blood group alloantibodies, which are detected only with AHG sera that contain anticomplement activity. Using monospecific anti-IgG AHG reagents to detect unexpected antibodies offers reliability while avoiding interference from some common and clinically insignificant IgM complement-fixing antibodies, and thereby saves time and expense.

Antibodies, Anti-Idiotypic↗
PubMed1990

Assessments of lung toxicity to Acrawax C following acute inhalation exposure.

Acrawax is a trademark for a series of synthetic waxes which are used as flatteners in paint, and lubricants in plastics, and these materials have been routinely regarded as nuisance dusts. Due to a paucity of information regarding the pulmonary toxicity of this material, we investigated the effects of acute inhalation of Acrawax C in rats. CD rats were exposed to aerosols of Acrawax C for 6 hours at 112 mg/m3. Fluids and cells from sham and exposed animals were recovered by bronchoalveolar lavage (BAL) and measured for cellular and biochemical parameters at 0, 24, 48, 172 hrs (8 days), and 1 month postexposure. Pulmonary macrophages (PM) were cultured and studied for in vitro and in vivo phagocytosis, as well as surface morphology. The lungs of additional animals exposed to Acrawax were fixed for assessment by histopathology, and transmission electron microscopy. Our results showed that Acrawax C exposure produced a mild inflammatory response at 24 hours postexposure, but cell differentials were not significantly different from controls at 48 hrs after exposure. BAL levels of lactate dehydrogenase, alkaline phosphatase and protein were slightly different from controls only at 8 days postexposure, and had returned to control values by 1 month of recovery. Acrawax exposure had no adverse effects on either morphology or the phagocytic capacity of pulmonary macrophages recovered from exposed animals. Histopathologic analysis of lung tissue from Acrawax C-exposed rats revealed normal lung architecture. Based on acute studies, our results suggest that the response to inhaled Acrawax C is not substantially different from the response to other nuisance dusts such as carbonyl iron and titanium dioxide.

Administration, Inhalation↗
PubMed1991

[The impact of impregnated mosquito nets on prevalence and morbidity related to malaria in sub-Saharan africa].

Insecticide treated bed nets (permethrin, deltamethrin and lambda cyalothrin) were used for malaria control in The Gambia, Burkina Faso and Tanzania where Anopheles gambiae (and An.funestus in Burkina Faso) is the main vector. Treated mosquito nets are efficient when used on a large scale and not on an individual level. Such a large scale use, acting on longevity and infectivity of vectors, always induced a decrease of malaria transmission by more than 90%. Treated bed nets had no significant effect on the overall parasite rate, showing that malaria transmission was not stopped. But it was usually found that there was a significantly smaller number of children with parasitemia higher than a critical threshold, a sensitive parameter of malaria morbidity. Indeed, in the three situations studied, malaria morbidity (fever + high parasitemia greater than critical level in the concerned area) has generally shown a similar drop of 60%. These data demonstrate that treated bed nets are useful to reduce transmission and morbidity. Advised as a new way for reduction of nuisance, treated bed nets were always welcomed by the populations and this method may be considered as a complementary weapon in public health.

Adolescent↗
PubMed2006

Adaptive design: estimation and inference with censored data in a semiparametric model.

In this article, we provide a method of estimation for the treatment effect in the adaptive design for censored survival data with or without adjusting for risk factors other than the treatment indicator. Within the semiparametric Cox proportional hazards model, we propose a bias-adjusted parameter estimator for the treatment coefficient and its asymptotic confidence interval at the end of the trial. The method for obtaining an asymptotic confidence interval and point estimator is based on a general distribution property of the final test statistic from the weighted linear rank statistics at the interims with or without considering the nuisance covariates. The computation of the estimates is straightforward. Extensive simulation studies show that the asymptotic confidence intervals have reasonable nominal probability of coverage, and the proposed point estimators are nearly unbiased with practical sample sizes.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

A Bayesian Approach to Model Selection in Hierarchical Mixtures-of-Experts Architectures.

There does not exist a statistical model that shows good performance on all tasks. Consequently, the model selection problem is unavoidable; investigators must decide which model is best at summarizing the data for each task of interest. This article presents an approach to the model selection problem in hierarchical mixtures-of-experts architectures. These architectures combine aspects of generalized linear models with those of finite mixture models in order to perform tasks via a recursive "divide-and-conquer" strategy. Markov chain Monte Carlo methodology is used to estimate the distribution of the architectures' parameters. One part of our approach to model selection attempts to estimate the worth of each component of an architecture so that relatively unused components can be pruned from the architecture's structure. A second part of this approach uses a Bayesian hypothesis testing procedure in order to differentiate inputs that carry useful information from nuisance inputs. Simulation results suggest that the approach presented here adheres to the dictum of Occam's razor; simple architectures that are adequate for summarizing the data are favored over more complex structures. Copyright 1997 Elsevier Science Ltd. All Rights Reserved.

Journal Article↗
PubMed2004

Scaling in domestic heating equipment: getting to know a complex phenomenon.

Excessive scaling is one of the main nuisances in relation to the use of drinking water. Ever more water companies try to minimise scaling. Although scaling is an old problem, prediction of scaling has been proven to be very tricky. Traditionally, the (Langelier) Saturation Index is used to evaluate scaling properties of drinking water. From experience it is well known that this parameter is not suitable for proper prediction. New parameters have been developed and standardised for scaling prediction, namely the Calcium Carbonate Precipitation Potential, calculated at a temperature of 90 degrees C (CCPP90); the Saturation Index, also calculated at a temperature of 90 degrees C (SI90); the Nucleation Index (NI) and the Measured Calcium Carbonate Precipitation (MCCP). These parameters are currently successfully used in The Netherlands. The development of new parameters to predict scaling in domestic heating equipment has resulted in a better understanding of processes involved. Even now unexpected and at first sight contradictory results are obtained frequently. With the use of the developed measuring techniques, solutions may be found to combat excessive scaling.

Calcium Carbonate↗
PubMed1992

Role of the alveolar macrophage in lung injury: studies with ultrafine particles.

We conducted a series of experiments with ultrafine particles (approximately 20 nm) and larger particles (less than 200 nm) of "nuisance" dusts to evaluate the involvement of alveolar macrophages (AM) in particle-induced lung injury and particle translocation in rats. After intratracheal instillation of both ultrafine particles and larger particles of TiO2, we found a highly increased interstitial access of the ultrafine particles combined with a large acute inflammatory reaction as determined by lung lavage parameters. An additional experiment revealed that intratracheal instillation of phagocytized ultrafine TiO2 particles (inside AM) prevented both the pulmonary inflammatory reaction and the interstitial access of the ultrafine particles. Another experiment showed that the influx of polymorphonuclear cells (PMN) into the alveolar space unexpectedly decreased with higher doses of ultrafine particles, whereas alveolar epithelial permeability (protein leakage) increased. The divergence between PMN influx into the alveolar space and changes in alveolar epithelial permeability implies that they are separate events. Pulmonary inflammatory parameters determined by lung lavage analysis correlated best with the surface area of the retained particles rather than with their mass, volume, or numbers. Because higher doses resulted in an increased interstitialized fraction of particles, we suggest that inflammatory events induced by particles in the interstitial space can modify the inflammation in the alveolar space detectable by lung lavage. Our results demonstrate the dual role of AM for modifying particle-induced lung injury, i.e., both preventing such injury and contributing to it. We conclude that the increased pulmonary toxicity of ultrafine particles is related to their larger surface area and to their increased interstitial access.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2003

Statistical analysis of honeybee survival after chronic exposure to insecticides.

Studies concerning long-term survival of honeybees raise the problem of the statistical analysis of mortality data. In the present study, we used a modeling approach of survival data of caged bees under chronic exposure to two pesticides (imidacloprid and deltamethrin). Our model, based on a Cox proportional hazard model, is not restricted to a specific hazard functional form, such as in parametric approaches, but takes into account multiple covariates. We consider not only the pesticide treatment but also a nuisance variable (variability between replicates). Moreover, considering the occurrence of social interactions, the model integrates the fact that bees do not die independently of each other. We demonstrate the chronic toxicity induced by imidacloprid and deltamethrin. Our results also underline the role of the replicate effect, the density-dependent effect, and their interactions with the treatment effect. None of these parameters can be neglected in the assessment of chronic toxicity of pesticides to the honeybee.

Animals↗
PubMed1993

Unwanted pregnancies: understanding contraceptive use and benefits in adolescents and older women.

The highest percentages of unintended pregnancies and the largest increases in births reported in the United States in recent years were in adolescents and in women more than 35 years of age. Increasing numbers of these women will require contraception to avoid unintended pregnancy. In adolescents the combined oral contraceptive agents protect fertility indirectly and exert favorable actions on menstrual dysfunction and certain hormone-related disorders such as acne and hirsutism. To avoid sexually transmitted disease, barrier protection should be used along with oral contraceptives until mutually monogamous, stable relationships are established. Healthy older women who are nonsmokers may also safely use currently available contraceptives. These agents have little impact on metabolic parameters linked to the development of cardiovascular disease. In addition to providing reliable contraception, oral contraceptives offer noncontraceptive benefits to older reproductive-age women, including control of abnormal bleeding and a reduction in the incidence of ovarian and endometrial cancers and other gynecologic pathology. Intrauterine devices and progestin implants are safe, effective, and underused in the United States. Progestin implants may have an additional role in patients for whom estrogen preparations are contraindicated. Counseling is very important before insertion because of the high rate of nuisance side effects. The contraception selection process must consider the efficacy and acceptability of the specific method to avoid the probability of unintended pregnancy and the risk of sexually transmitted diseases.

Adolescent↗
PubMedDate not supplied

Utilizing combination therapy to optimize melasma outcomes.

Melasma is a chronic and recurrent disorder. It has been underdiagnosed and undertreated due to lack of effective therapies and the perception that it is merely a cosmetic nuisance. Hydroquinone, corticosteroids, licorice extracts and kojic acid have been used as monotherapy to treat melasma. However, the present standard of care in melasma therapy is combination therapy. To date, the most effective treatment is a triple-combination agent that contains hydroquinone 4%, tretinoin 0.05% and fluocinolone acetonide 0.01%. In clinical trials, its use led to complete or near-complete clearing of melasma in 8 weeks. A long-term study demonstrated its continuing efficacy and safety for as long as 360 days. In an examination of quality of life parameters, patients using the triple-combination cream showed significant improvements in self-perception by all 1290 patients. Various combinations of melasma therapy, such as chemical peels, particularly as adjuvants to the triple-combination cream, are discussed.

Administration, Cutaneous↗
PubMed2003

Indoor aldehydes: measurement of contamination levels and identification of their determinants in Paris dwellings.

The recent increased prevalence of childhood asthma and atopy has brought into question the impact of outdoor pollutants and indoor air quality. The contributory role of aldehydes to this problem and the fact that they are mainly derived from the domestic environment make them of particular interest. This study therefore measures six different aldehyde levels in Paris dwellings from potentially different sources and identifies their indoor determinants. The study was carried out in the three principal rooms of 61 flats with no previous history of complaint for olfactory nuisance or specific symptoms, two-thirds of the flats having been recently refurbished. Aldehydes were sampled in these rooms using passive samplers, and a questionnaire on potential aldehyde sources was filled out at the same time. A multiple linear regression model was used to investigate indoor aldehyde determinants. Our study revealed that propionaldehyde and benzaldehyde were of minor importance compared to formaldehyde, acetaldehyde, pentanal, and hexanal. We found that levels of these last four compounds depended on the age of wall or floor coverings (renovations less than 1 year old), smoking, and ambient parameters (carbon dioxide levels, temperature). These results could help in the assessment of indoor aldehyde emissions.

Air Pollution, Indoor↗
PubMed1995

A caveat concerning independence estimating equations with multivariate binary data.

Clustered binary data occur commonly in both the biomedical and health sciences. In this paper, we consider logistic regression models for multivariate binary responses, where the association between the responses is largely regarded as a nuisance characteristic of the data. In particular, we consider the estimator based on independence estimating equations (IEE), which assumes that the responses are independent. This estimator has been shown to be nearly efficient when compared with maximum likelihood (ML) and generalized estimating equations (GEE) in a variety of settings. The purpose of this paper is to highlight a circumstance where assuming independence can lead to quite substantial losses of efficiency. In particular, when the covariate design includes within-cluster covariates, assuming independence can lead to a considerable loss of efficiency in estimating the regression parameters associated with those covariates.

Biometry↗
PubMed2006

Reduction of malodorous compounds from a treated swine anaerobic lagoon.

There is a need for treatment technologies that can eliminate environmental problems associated with anaerobic lagoons. These technologies must be able to capture nutrients, kill pathogens, and reduce emissions of ammonia and nuisance odors. To meet these needs, a full-scale wastewater treatment plant was installed as a demonstration project on one of three 4360-pig (Sus scrofa) production units in a finishing farm in Duplin County, North Carolina. Once the treatment plant was operational, flow of raw manure into the unit's corresponding lagoon was discontinued and the lagoon was used to store treated wastewater. Water quality was monitored in the converted lagoon and in the two conventional lagoons. A gas chromatographic method was developed to measure concentration of five selected malodorous compounds (phenol, p-cresol, 4-ethylphenol, indole, and skatole) in liquid lagoon samples. Dramatic improvements in the water quality parameters TKN, NH3-N, solids, COD, and BOD in the converted waste lagoon paralleled reductions in malodorous compounds. Nine months after conversion, identified malodorous compounds in liquid extractions averaged 6.6 and 38.8 ng mL(-1) in water from the converted lagoon and the conventional lagoons, respectively. The reduction was particularly marked for p-cresol, 4-ethylphenol, and skatole, all of which make important contributions to swine waste odors due to their characteristic odors and low detection thresholds.

Anaerobiosis↗
PubMed2006

Generalized additive modeling with implicit variable selection by likelihood-based boosting.

The use of generalized additive models in statistical data analysis suffers from the restriction to few explanatory variables and the problems of selection of smoothing parameters. Generalized additive model boosting circumvents these problems by means of stagewise fitting of weak learners. A fitting procedure is derived which works for all simple exponential family distributions, including binomial, Poisson, and normal response variables. The procedure combines the selection of variables and the determination of the appropriate amount of smoothing. Penalized regression splines and the newly introduced penalized stumps are considered as weak learners. Estimates of standard deviations and stopping criteria, which are notorious problems in iterative procedures, are based on an approximate hat matrix. The method is shown to be a strong competitor to common procedures for the fitting of generalized additive models. In particular, in high-dimensional settings with many nuisance predictor variables it performs very well.

Biometry↗
PubMed1988

Evidence of allergic hypersensitivity to chironomid midges in an English village community.

Some chironomid (non-biting) midges contain potent human allergens, principally in the form of insect haemoglobins. In view of previously demonstrated immunological cross-reactivity between some different midge species, the possible role of British midges in allergic disease was studied. The chosen site, Farmoor near Oxford, is a village that has been subject to several annual nuisance midge swarms since the construction of an adjacent water-supply reservoir in 1964, which was extended in 1975. The incidence and severity of hypersensitivity in the community was assessed by questionnaire survey, skin-prick testing, radio-allergosorbent tests (RAST) and RAST inhibition, and enzyme-linked immunosorbent assays (ELISA) and ELISA inhibition, using extracts of locally caught adult midges (Tanytarsus sylvaticus, T. bathophilus and Chironomus anthracinus) and laboratory cultured larvae (C. riparius). These tests revealed a low but significant level of midge-related hypersensitivity with skin-prick results showing seasonal fluctuations, but this seasonality was not confirmed with an IgE RAST. A correlation between IgE levels and relevant symptoms was found (P less than 0.01) using RAST, but not between IgE and skin-test results. Enzyme-linked immunosorbent assay results did not correlate with any other parameter measured. The incidence and severity of allergic reactions to the midges tested in this community was low.

Adult↗
PubMed2004

Uranium removal from aqueous solution by coir pith: equilibrium and kinetic studies.

Basic aspects of uranium adsorption by coir pith have been investigated by batch equilibration. The influence of different experimental parameters such as final solution pH, adsorbent dosage, sorption time, temperature and various concentrations of uranium on uptake were evaluated. Maximum uranium adsorption was observed in the pH range 4.0-6.0. The Freundlich and Langmuir adsorption models were used for the mathematical description of the adsorption equilibrium. The equilibrium data fitted well to both the equilibrium models in the studied concentration range of uranium (200-800 mg/l) and temperatures (305-336 K). The coir pith exhibited the highest uptake capacity for uranium at 317 K, at the final solution pH value of 4.3 and at the initial uranium concentration of 800 mg/l. The kinetics of the adsorption process followed a second-order adsorption. The adsorbent used proved to be suitable for removal of uranium from aqueous solutions. 0.2 N HCl was effective in uranium desorption. The results indicated that the naturally abundant coir pith of otherwise nuisance value exhibited considerable potential for application in removal of uranium from aqueous solution.

Absorption↗