Microplastics (MPs) are plastic particles less than 5 mm in diameter. These contaminants are increasingly found in the environment due to increased plastic production, use, and improper disposal. Detecting and measuring these contaminants in the environment has proven difficult, requiring the use of fate and transport models to assess MP...
Heteroaggregation of nanoparticles with naturally occurring colloids has been shown to be an important process in nanoparticle fate and transport in the aquatic environment. The advent of a functional assay to measure heteroaggregation attachment efficiencies has opened the door for further mechanistic studies. It is well known that natural organic...
Engineered nanomaterials (ENMs) are small anthropogenic colloids with at least one length dimension <100 nanometers. Due to the nature of their use, ENMs are being increasingly released to the environment. Yet the environmental risks posed by ENMs are unknown due to a variety challenges, including limitations with detecting and quantifying...
Metal oxide nanoparticles (MONPs) are manufactured at the greatest rate of any class of nanomaterial due to their wide variety of industrial, commercial, and environmental applications. The sustainable use of MONPs requires a balance of careful consideration of their potential negative environmental impacts with the effective exploitation of their unique...
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JeffreyA. Nason
Metal oxide nanoparticles (MONPs) are manufactured at the greatest rate of
The widespread use of engineered nanoparticles (ENPs) in industrial applications and consumer products makes their release to the environment inevitable. Understanding the aggregation behavior of ENPs is crucial to understanding their fate, transport and toxicology in aquatic systems. This study investigated the comparability of experimentally-determined and model-estimated attachment efficiencies for...
Contamination of stormwater with Cu⁺², Pb⁺², and Zn⁺² has become an important issue with recognition of the neurotoxic effects of these metal ions on aquatic life. Low levels of aqueous Cu⁺² disrupt olfactory functioning in endangered Pacific Northwest salmon, decreasing their ability to avoid predation. One common solution is stormwater...
This study investigates the relationship between total and ionic copper in samples taken from the Tualatin River and wastewater treatment facilities (WWTFs) that discharge into the Tualatin River. Copper speciation was analyzed by determining conditional stability constants and densities of copper binding ligands on the dissolved organic matter (DOM) in...
Low concentrations of dissolved copper have proven to be harmful to a number of aquatic organisms, with recent research highlighting detrimental effects to endangered salmonid species. Stormwater runoff can represent a significant source of copper to surface waters, necessitating cost-effective alternatives to current stormwater best management practices (BMPs). This study...
Nanoparticles are becoming increasingly important in numerous technological fields but evidence shows that they can be toxic to many organisms. To predict their fate and transport in the environment, nanoparticle attachment to naturally occurring colloids must be examined. This study investigated citrate-capped gold nanoparticle (Cit-AuNP) heteroaggregation with two model colloids...
Understanding the aggregation behavior of engineered nanomaterials (ENMs) in aqueous environments is essential to understanding their fate, transport, and toxicity. Because naturally occurring colloids will likely be present at much higher concentrations than ENMs in environmental systems, heteroaggregation and attachment with these natural colloids could significantly influence ENM fate and...
Current best management practices (BMPs) for stormwater treatment are not able to adequately remove heavy metals to levels which do not adversely affect aquatic life. Copper is commonly found in highway stormwater runoff, with the primary source being brake pad wear. Copper is of particular concern due to inhibitory effects...
Copper and zinc are heavy metals commonly present in highway stormwater runoff. Discharge of these metals to surface waters inhabited by sensitive aquatic species including threatened and endangered salmonids has necessitated the need for improved treatment techniques. Although copper is of the greater toxicological concern, zinc is often present at...
Coagulation and flocculation are commonly used in drinking water treatment
as a means of destabilizing and aggregating particles and promoting adsorption of
dissolved organic carbon (DOC). In practice, jar tests are used to determine optimal
conditions for the removal of turbidity and DOC. However, beyond the inferences
that can be...
Low levels of copper have been shown to impair the olfactory system of threatened and
endangered (T&E) salmon, decreasing their predator avoidance behavior and likely
increasing mortality. However, only dissolved copper (dissCu) present as the cupric ion
(Cu2+) and weakly complexed species are truly bioavailable. Previous studies indicate the
vast...
Heavy metals, such as copper, zinc, and cadmium, are ubiquitous in stormwater and potentially toxic to aquatic organisms at low concentrations. Removal of heavy metals contamination by conventional treatment is expensive and does not always reduce metals concentrations low enough to ensure safety of all aquatic species. This research seeks...
The purpose of this research was to measure the copper-binding behavior of Dissolved Organic Matter (DOM) contained in Pulp and Paper (P&P) wastewater effluent and evaluate the Biotic Ligand Model’s (BLM) ability to quantify copper speciation in P&P influenced waters. A copper ion selective electrode was used to measure copper...
Recent studies have discovered that salmon, specifically juvenile Coho Salmon, have their olfactory senses inhibited by the presence of low concentrations of copper concentrations at very low concentrations. Much of this copper is deposited on roadways by car brake pads during their use. The copper is carried with stormwater into...
In order to better predict the aggregation state of nanomaterials, the factors that influence aggregation must be understood. The combined effects of natural and engineered coatings have been shown to factor into nanoparticle aggregation behavior in preliminary research. In this study, aggregation behaviors of gold nanoparticles with two different engineered...
The adsorption of natural organic matter (NOM) to the surfaces of natural colloids
and engineered nanoparticles is known to strongly influence, and in some cases control,
their surface properties and aggregation behavior. As a result, the understanding of
nanoparticle fate, transport and toxicity in natural systems must include a fundamental...
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JeffreyA. Nason
The adsorption of natural organic matter (NOM) to the surfaces of
The production of the fullerene C60 and its emerging applications in consumer
products imply its ultimate release to the environment. Due to the molecule’s relative
novelty, the aqueous characteristics of C60 have not been fully assessed, though it may
potentially harm human or ecological health. C60 is highly insoluble in...
The production of titanium dioxide (TiO2) nanoparticles has increased significantly in the past decades, which has generated concern due to their known toxicity in the environment. As a result of the production, use and disposal of productions containing TiO2, TiO2 nanoparticles are often received by wastewater treatment facilities. The adsorption...
The purpose of this study was to investigate the effect of an integrated adapted
physical education setting on the motor performance of preschool children with
developmental delays. Subjects in this study participated in segregated and integrated
adapted physical education classes. During the integrated conditions, same-age peers
without delays participated in...
The purpose of this investigation was to determine the validity and
reliability of the Nicholas Manual Muscle Tester (NMMT), a portable
dynamometer, as a measure of the isometric strength in women with arthritis.
Female subjects (N=13; 66 ± 13.89 yrs.) with arthritis were tested for
isometric muscle strength on the...
The purpose of this study was to compare the levels of bone
mineral density (BMD) of the whole body (WB) and proximal
femurs of physically active men with spinal cord injuries (SCI) to
nonactive men with spinal cord injuries. Also, the lean muscle
mass (LMM) of active men with SCI...
Balance is the ability to establish an equilibrium between the body and its environment. Balance is a key component which is associated with a variety of movements and postural control. Children with cerebral palsy (CP) have difficulties with movement and postural control due to physical and neurological limitations. The purpose...
The purpose of this study was to determine if a 5-month
progressive-resistance exercise program would affect measures
of activities of daily living (ADLs) and functional stability
in elderly women. All subjects were ambulatory women, 80 to
93 years old, who lived in assisted-care facilities. Eight
exercise and 7 control subjects...
This study compared the effect of two sources of instruction and verbal
encouragement on the participation of individuals with mental retardation (MR) in a 10-week physical activity program. Participants were 17 adult employees of a sheltered
workshop (5 females, 12 males) ranging in age from 30 to 65 years. The...
A common perspective promoted by health care professionals is that exercise may help reduce symptoms and improve activities of daily living among persons with multiple sclerosis (MS). Yet, the effects of resistance exercise on power, functional mobility, and fatigue are largely unknown. The purpose of this study was to examine...
In the realms of psychology and sociology two new theoretical models have arisen to describe the forces influencing altruistic human behavior. The first is the Empathy-Altruism Hypothesis (EAH), by C.D. Batson. The second is the Conceptual Continuum of Altruism (CCA), by K.R. Monroe. Both models have proven to be highly...
The focus of this research was to gain an understanding of physical activity in elementary school-aged children with mental retardation (MR). The primary purpose of the first study was to investigate physical activity levels of children with and without MR in both school and out of school environments. The secondary...
Glioblastoma is the most malignant primary brain tumor with the average
patients surviving only one year after diagnosis, even with aggressive therapy. The
formation of numerous micro-tumors dispersed into the brain due to rapid invasion of
tumor cells, presents the primary challenge to the surgical removal of tumors and
limits...
The use of paraeducators has increased as a main mechanism to include more
students with disabilities in multiple settings in the public schools in the U.S.
Research has examined the use of paraeducators in typical classroom settings but
little is known about their role in physical education. Although the utilization...
The purpose of this study was to examine the evidence of construct validity for self-report with assistance from a secondary source as a measure of physical activity (PA) in adults with intellectual disabilities (ID) in free-living environments. Thirty-seven participants (21 females, 16 males) with mild to moderate ID aged 19-74...
Muscle weakness and fatigue are debilitating symptoms of multiple sclerosis (MS). Approximately 50% of muscle weakness and fatigue have been attributed to deficits within the peripheral nervous system, specifically mechanisms residing in the muscle. The goals of this study were to identify the cellular mechanisms of contraction within the muscle...
The aim of the first manuscript was to examine CHD risk in women with MS by
assessing the frequency of physical inactivity and the frequency of anthropometric,
dietary, and metabolic CHD risk factors. Although participation in physical activity is
often avoided by many women with MS, some women remain physically...
Logging and forest thinning operations generate large amounts of residues in the form of small trees, branches and foliage that are usually left on the ground to decay or are burned. These resources are readily available, but it is uneconomical to remove them from the forest. The potential utilization of...
Participation in physical activity has important health benefits among individuals with disabilities, whereas inactive lifestyles may lead to secondary limiting health conditions. However, few people with disabilities regularly participate in the recommended amount of health-related physical activities. Low rate of participation may be related to low motivation due to interconnected...
Alteration of natural areas in attempts to support increasing human populations has been a crucial yet less publicized contributor to the fall of many of the world's greatest civilizations, since healthy ecosystems can help maintain stable societies and economies. Given this unhappy fact and the ancient relationship between people and...
This paper presents a framework for analyzing efficient spatial allocation of forest
management efforts - fuel treatment and harvest - under the risk of fire. The framework
integrates a fire behavior model and a spatially-explicit stochastic dynamic optimization
model. I investigate the effects of spatial interaction across plots during forest...