Currently, there is an elevated interest in reducing feeding damage caused by the Nantucket pine tip moth, Rhyacionia frustrana (Comstock), a common regeneration pest of loblolly pine, Pinus taeda L. The toxicity of several insecticides was tested in a laboratory against four common R. frustrana parasitoids. There were no differences ...

Exposure to microbes present in mould-damaged buildings has been linked to increased frequency of various inflammatory diseases. The current study examined differences in inflammatory mediators in nasal lavage (NAL), induced sputum (IS) and serum of occupants with rheumatic or respiratory disorders and their controls, all working in the same moisture-damaged ...

1,3-Butadiene (BD), a suspected human carcinogen, is used as the raw material in industries to make synthetic butyl rubber and plastics. Simulation models using experimental animal data have shown that physiologic factors play an important role in the kinetic behavior of BD. However, human data are limited. The aim of ...

Project MOHAVE was a major air quality and visibility research program conducted from 1990 to 1999 to investigate the causes of visibility impairment in the Grand Canyon National Park region. At Meadview, a remote monitoring site just west of the Grand Canyon National Park, on September 1 and 2, 1992, ...

The objective of this study was to investigate the effect of disinfectant concentration and pH on the inactivation kinetics of Cryptosporidium parvum oocysts with ozone, monochloramine, and ozone/monochloramine at 20 degrees C. Experimental results revealed that the CT (product of disinfectant concentration and contact time) required to achieve a certain ...

Annual mean concentrations in air and annual total (wet plus dry) depositions to ground of 90Sr, 137Cs, 238Pu and (239,240)Pu decreased at Neuherberg, south Germany, in the period from July 1986 (i.e. after the end of the initial deposition phase from Chernobyl) to 1998 as follows: 90Sr from 0.77 to ...

INTRODUCTION: Exposure to 35,000 ft without preoxygenation (breathing 100% oxygen prior to decompression) can result in severe decompression sickness (DCS). Exercise while decompressed increases the incidence and severity of symptoms. Clarification of the level of activity vs. time to symptom onset is needed to refine recommendations for current operations requiring ...

The exposures and work activities of 41 applicators in North Carolina using chlorpyrifos-containing termiticides were characterized. Personal air and urine samples were collected on multiple days within one week. Detailed information about chemical use, tasks, personal protective equipment and hygiene was recorded. During the 202 applicator-days monitored, 415 treatment jobs ...

This experimental study assessed the role of the microhabitat in the uptake of metals by adult acanthocephalans. We examined the accumulation of lead by adult Pomphorhynchus laevis in the intestine of chub (Leuciscus cephalus) and compared it with that in goldfish, Carassius auratus auratus, in which the parasites penetrate the ...

In three freezing experiments we examined the freeze tolerance in newborn adders, Vipera berus, from East-central Sweden. After a two to three hours exposure to freezing, ten out of eleven fast frozen snakes survived and recovered completely after being exposed to -3.1 degrees C on average. In the other two ...

To assess DNA damage remaining in peripheral lymphocytes, 48 individuals were evaluated twice for lymphocyte micronucleus frequencies by the cytokinesis-blocking cytochalasin B (CBMN) analysis post relocation from radio-contaminated apartments after various periods of time. The frequencies of CBMN at the first evaluation were significantly higher than those at the second ...

Ozone exposure aggravates asthma, as has been demonstrated in both controlled exposures and epidemiologic studies. In the current double-blind crossover study, the authors evaluated the effects of dietary antioxidants (i.e., 400 IU vitamin E/500 mg vitamin C) on ozone-induced bronchial hyperresponsiveness in adult subjects with asthma. Seventeen subjects were exposed ...

We examined the effect of tetracaine aerosol inhalation, a local anesthetic, on lung volume decrements, rapid shallow breathing, and subjective symptoms of breathing discomfort induced by the acute inhalation of 0.30 ppm ozone for 65 min in 22 ozone-sensitive healthy human subjects. After 50 min of ozone inhalation FEV(1) was ...

Sulphur dioxide (SO2) is an important air pollutant and causes bronchoconstriction in normal and asthmatic adults. This paper has explored the autonomic consequences of SO2 exposure using the spectral analysis of heart rate variability. Electrocardiogram recordings were made in 12 normal and 12 asthmatic adults undergoing pollutant exposures. Exposures were ...

The widespread use of cholinesterase-inhibiting pesticides in the environment presents increasing concerns about their effects on human, wildlife, and ecosystem health. As a group, these pesticides are generally highly toxic and have great potential for negatively affecting nontarget organisms. Small mammals have proven to be ideal biomonitors of environmental contaminants, ...

Vitellogenin is a phospholipoglycoprotein precursor of egg yolk. In mature female fish, vitellogenin is synthesized and secreted by the liver in response to circulating estrogens. Vitellogenin is normally undetectable in the blood of male fish, but can be induced by exposure to compounds possessing estrogenic activity. Thus, the presence of ...

BACKGROUND: The development of metastatic disease throughout the neuroaxis from primary central nervous system (CNS) tumors and non-CNS tumors suggests the cerebrospinal fluid (CSF) is an important source of exposure for chemotherapeutic agents. In non-human primates, a 4-hour, as compared to a 30-minute, topotecan (TPT) infusion prolonged TPT exposure in ...

The growth of 1-year-old aspen was simulated using TREGRO, a computer simulation model of individual tree growth, to assess potential effects of ozone (O3). TREGRO was parameterized using information from a field experiment conducted at Ithaca, NY, USA; the model was then applied using environmental information from Suwon, Korea, where ...

OBJECTIVE: The use of camp stoves in an enclosed or poorly ventilated space is clearly not recommended due to the risk of carbon monoxide (CO) poisoning. Instances may arise, however, when use for a limited time is necessary. We sought to find differences in CO levels between various fuels used ...

Differences in auditory thresholds and distortion-product otoacoustic emission (DPOAE) levels were investigated as a function of gender, ear, frequency, and experimental condition: quiet sedentary activity, exercise, noise, and exercise and noise combined. In general, participants displayed significant elevations in auditory thresholds of approximately 6 to 13 dB following the two ...

The majority of insecticides currently in use are organophosphorus, carbamate, and synthetic pyrethroid compounds. Organophosphorus insecticides (OPs) produce toxicity by inhibiting the cholinesterase enzymes in the nervous system. Monitoring of acetylcholinesterase (AChE) inhibition has been widely used in terrestrial and freshwater aquatic systems as an indicator of OP exposure and ...

We measured airborne exposures to the biological insecticide Bacillus thuringiensis var. kurstaki (Btk) during an aerial spray program to eradicate gypsy moths on the west coast of Canada. We aimed to determine whether staying indoors during spraying reduced exposures, to determine the rate of temporal decay of airborne concentrations, and ...

OBJECTIVE: To measure the concentration of microbial aerosols in general dental practices and to use this information to carry out quantitative microbiological risk assessments. METHODOLOGY: Microbial air sampling was carried out continuously during 12 treatment sessions in 6 general dental practices in the South West of England. RESULTS: The microbial ...

Indomethacin has been used to demonstrate that cyclooxygenase (COX) metabolites of arachidonic acid play a mechanistic role in ozone-induced spirometric decline in normals (Nm). Since the weight of evidence suggests that asthmatics (Asth) do not differ substantially from Nm subjects in the magnitude of their spirometric response to ozone, we ...

From the perspective that disgust is a core feature of spider phobia, we investigated whether the treatment efficacy could be improved by adding a counterconditioning procedure. Women with a clinically diagnosed spider phobia (N = 34) were randomly assigned to the regular one-session exposure condition (EXP) or to the exposure ...

Exposure of isolated photosystem I (PSI) complexes to illumination (2300 microE m(-2) s(-1)) for various periods of time resulted in striking changes in their absorption spectra. A 6 nm blueshift of the absorption maximum in the red was detected after 100 min illumination. The fourth derivative of the absorption spectra ...

Within the last decade, the comet assay has been used with increasing popularity to investigate the level of DNA damage in terms of strand breaks and alkaline labile sites in biomonitoring studies. The assay is easily performed on WBCs and has been included in a wide range of biomonitoring studies ...

The objectives of this study were: 1) to determine if chlorine exposure at low levels induces nasal effects in humans as it does in rodents; and 2) to establish a possible occurrence of respiratory effects in human volunteers exposed to chlorine vapour at concentrations of 0, 0.1, 0.3 and 0.5 ...

Fruits of Garden Lettuce, imbibed in 0.01 M KNO3, were depleted of maternal active phytochrome B by saturating deep-red exposure and photosensitized by chilling for 1 week at 4 degrees C. Twenty saturated fluence-response curves for photoinduced germination were elaborated between 300 and 800 nm, using exposure periods from 6 ...

A possible method of control for the management of wild populations consists of continual introgression of an inducible transgene by releasing transgenic individuals, with periodic exposure of the population to a trigger. Exposure to the trigger causes death or sterility in carriers of the transgene, but is otherwise benign. We ...

OBJECTIVE: To monitor the effect of a novel nicotine delivery device that may produce fewer carcinogens (Eclipse) on cigarette smoking, carbon monoxide and nicotine concentrations, and motivation to give up smoking. The smoker's own brand of cigarette and a nicotine replacement product (Nicotrol inhaler) were used as comparisons. DESIGN: After ...

There is substantial evidence that magnetic field (MF) exposure influences melatonin secretion in animals. However, data on its influence on human melatonin levels are scarce, and seemingly contradictory. Because of its many beneficial effects, very low-frequency MF exposure is used in physiotherapy of some neurological diseases and overloading syndromes of ...

Chemical monitoring for butyltins in bulk seawater, surface microlayer and superficial sediments determined that the two main local sources of marine contamination by tributyltin (TBT) compounds in Malta are ship-repairing dockyards and marinas. In bulk seawater, TBT values ranged from below the detection limit of 5 ng Sn l(-1) to ...

Effects of sublethal exposure to abamectin on the biological performance of Neoseiulus longispinosus (Evans) were studied under ambient laboratory conditions of 28 +/- 2 degrees C and 80 +/- 15% RH with 24 h light. The red form of the twospotted spider mite, Tetranychus urticae Koch, complex (Acari: Tetranychidae), was ...

There are endogenous intracellular mechanisms that provide cells with protection from stress, as well as repair from damage. These pathways often involve stress proteins and neurotrophic factors. The present study used Western blot analysis to examine changes in glial cell line-derived neurotrophic factor (GDNF) following noise overstimulation. A noise exposure ...

Exposure to inhalable particulates and dermal exposure to cyclohexane soluble matter (CSM) were evaluated in seven rubber manufacturing companies in 1988 and 1997. The identified exposure trends were used to study the effectiveness of control measures implemented over a nine-year period. Sampling and analytical methodologies were identical in both surveys. ...

A series of experiments was conducted to determine the effect of a flour food source on survival of red flour beetle, Tribolium castaneum (Herbst), and confused flour beetle, Tribolium confusum (DuVal), exposed to the labeled rate (0.5 mg/cm2) of Protect-It, a marine formulation of diatomaceous earth. Beetles were exposed at ...

Amphibian larvae are commonly exposed to low levels of pesticides during their development. Chronic studies generally examine the effects of long-term exposure, but they often disregard the importance of the individual life stage at which tadpoles are exposed. I determined the point during development at which carbaryl effects are manifested ...

Artificial gravity will be considered for long-duration spaceflight missions. Recent studies have shown that continuous exposure to gravity does not appear necessary to prevent the adverse effects of weightlessness, instead intermittent exposure may suffice. Vernikos et al reported that 1 G intermittent exposures with and without walking exercise was effective ...

The impact of particle size of aerosolized polymeric diphenylmethane-4,4'-diisocyanate (MDI) for the induction and elicitation of respiratory sensitization was evaluated. Four groups of 16 female guinea pigs each received either the vehicle, repeated intradermal (id) injections (3 x 0.3% MDI), one high-level inhalation exposure of 15 min to 135 mg ...

Laboratory-based studies have shown that ozone and nitrogen dioxide can potentiate the effect of allergen in sensitized asthmatic subjects, but it is not known whether this interaction is important under natural exposure conditions. Thirty-five subjects with clinical diagnoses of asthma or chronic obstructive pulmonary disease and with a provocative dose ...

Recently it has been observed that birth rates in Teplice, a highly polluted district in Northern Bohemia, have been reduced during periods when sulfur dioxide levels were high. This study, which is based on data from 2,585 parental pairs in the same region, describes an analysis of the impact of ...

In order to assess the potential of hydropsychid capture net anomalies as a bioindicator of chronic toxicity in streams and rivers, the effects of 2,4-dichlorophenol (2,4-DCP) exposure on the net-spinning behavior of Hydropsyche slossonae were examined for anomalies after 0, 5, 10, 15, and 20 exposure days to gradient concentration ...

BACKGROUND: The effects of blast on maximal exercise performance were investigated in sheep that were trained to perform maximal exercise. METHODS AND RESULTS: Sheep were fully instrumented for determination of pulmonary and systemic hemodynamics. Blast exposure was administered by using a compressed air driven shock tube that was positioned to ...

Despite a plethora of findings associated with the pathophysiology of malignant hyperthermia (MH), the in vitro contracture test (IVCT) is the only reliable test for diagnosis of this heterogeneous syndrome in man. An increase of 1,4,5-IP3 (inositol 1,4,5-trisphosphate), a second messenger involved in cellular calcium homeostasis, has been observed in ...

The relationship between metallothionein levels and concentrations of several metals and radionuclides was examined in liver tissues of raccoons (Procyon lotor, n = 47) from the Department of Energy's Savannah River Site in South Carolina to determine the applicability of metallothioneins as an initial screening device for exposure assessment in ...

The aim of this study was to investigate the cellular and biochemical events associated with repeated exposures to ozone. Twenty-three healthy subjects underwent single exposures to 200 ppb ozone and to filtered air (FA), as well as repeated exposures to 200 ppb ozone on 4 consecutive days, each for 4 ...

A total of five hundred sawmillers in Ibadan were studied to assess occupation-induced lung impairment as a result of exposure to saw dust. Occupation-related symptoms were recorded using structured questionnaire. Age and sex matched controls consisting of 500 University College Hospital (UCH) Ibadan workers or students were used. They were ...

STUDY OBJECTIVES: Acute exposure to the air in swine confinement units causes bronchial hyperresponsiveness and inflammation of the airways. This study was performed to assess the longitudinal development of bronchial responsiveness in pig farmers and to establish exposure-response relationships. METHODS: A cohort of 171 pig farmers was followed over a ...

While it is well known that exercise minute ventilation (V(E)) results in greater pulmonary function and subjective symptoms (SS) responses upon exposure to a given ozone (O3) dose, the magnitude of V(E) increase to produce a significant forced expiratory volume in 1 s (FEV1.0) response compared to that observed at ...