Spelling suggestions: "subject:"invasive"" "subject:"lnvasive""
951 |
Factors influencing the occurrence and spread of aquatic invasive species in watershed systemsOrtiz, Hazel M 01 September 2023 (has links) (PDF)
Watershed systems are experiencing rapid changes to water quality and hydrologic regimes due in part to climate-induced changes in temperature and precipitation, urbanization, and increases in aquatic invasive species. Aquatic invasive species are one of the primary threats to ecosystems, contributing to loss of biodiversity, altered hydrologic regimes, and stream degradation. Urban land use and climatic factors influence the spread of invasive species, presenting greater challenges for future invasive species management. There is a need for more research that evaluates the watershed process in connection with urban land use and climate change factors in relation to invasive species spread. This study will examine factors of climate change and land use that may be influencing the spread and occurrence of aquatic invasive plants within the Connecticut River watershed. There will be four species involved in this study: Eurasian milfoil (Myriophyllum spicatum), Variable milfoil (Myriophyllum heterophyllum), Hydrilla (Hydrilla verticillate), and the European water chestnut (Trapa natans). Hydrological conditions within the watershed will be analyzed using the SWAT model through the HAWQS interface. ArcGIS Pro will be used to combine and prepare data so that it may be utilized through MaxEnt. MaxEnt will be used to create species distribution models to estimate the probability of the presence of invasive aquatic plant species in the Connecticut river watershed.
|
952 |
Non-Invasive Techniques for the Detection and Diagnosis of DementiaBlount, Joseph A. January 2021 (has links)
It is estimated that there are currently fifty million people living with
dementia worldwide. An accurate and early diagnosis of dementia is important
in order to initiate appropriate treatment programs as soon as possible.
Common methods of neuropsychological assessment can be sensitive to
external factors which may compromise accuracy. The aim of this thesis was
to investigate techniques that have the potential for the detection of dementia
that avoid some of the external influences.
The thesis looked at measurements of (i) postural stability (ii) facial
analysis and (iii) fully-immersive virtual reality in cognitively-healthy
individuals. These techniques were chosen as postural stability and facial
analysis change in dementia and whilst virtual reality has previously been used
in dementia research, fully-immersive virtual reality measures have not been
established. To see if the measurements were associated with cognitive
function, participants completed a series of cognitive tests.
Results indicate that all techniques explored shared a relationship with
memory performance, with lower anteroposterior postural sway (F(1,22) =
17.76, p < 0.01), number of activities participated in that involve a posture
element (F(2, 39) = 3.77, p < .05; Wilk's Λ = 0.84, partial η2 = 0.16), the greater
the frequency of negative facial expressions (F(2, 18) = 4.49, p < .05; Wilk's Λ
= 0.67, partial η2 = 0.33.), and low blink rate (t(11.02) = 2.62 p < .05) all
showing better scores on memory tests. Moreover, better scores on the fullyimmersive
virtual reality task predicted better scores on with short-term
memory (F(1,22) = 20.20 p < 0.01), LTM (F(1,22) = 09.10 p < .01), associative
learning (F(1,22) = 08.75 p < .01), and a dual–task test
(F(1,22) = 04.64 p < .05).
The novel findings that elements such as postural stability, participation
in sports, facial expressions of emotion, blink rates, and spatial memory as
assessed in fully-immersive virtual reality highlight that non-invasive
techniques can provide measurements that correspond to cognitive ability.
This may hold implications for dementia diagnoses. Future research should
assess whether these relationships can also be found in an older adult
population. If this relationship is found in older adults, it could justify further
research into how these techniques could be applied in a clinical context.
|
953 |
Non-invasive positive pressure ventilation (nppv) its uses, complications, & implications within nursing practice in acute care settingsMarano, Alexis 01 December 2012 (has links)
The use of noninvasive positive pressure ventilation (NPPV) in acute care settings has drastically increased within the past 20 years. Research has indicated that NPPV is equally as effective as traditional mechanical ventilation(MV) in treating acute exacerbations of chronic pulmonary obstructive disease (COPD) and cardiogenic pulmonary edema. Furthermore, the risk of complication from NPPV is much lower than MV, in terms of ventilator-associated pneumonia and sepsis. It is imperative for the nurse to understand the various indications, interfaces, and potential complications associated with NPPV use. In addition to treating acute exacerbations of COPD and cardiogenic pulmonary edema, NPPV has been used for prevention of reintubation, palliative care, and status asthmaticus. Furthermore, NPPV could be delivered through various interfaces, such as nasal, facial, and helmet. Each of these interfaces could eventually cause complications for the patient, such as skin ulceration and sepsis. However, there is limited amount of research available discussing the role of the nurse in caring for the patient with NPPV. There are no standardized guidelines established to assist the nurse in this care, in terms of interface selection, prevention of complications, and staffing patterns. Several recommendations are presented at the end of this thesis to guide future nursing research, education, and clinical practice, such as exploring the role of oral care and education for NPPV patients.
|
954 |
Transgenerational Effects of Kin Recognition in Plants: Soil Conditioning by an Invasive PlantWu, Albert January 2021 (has links)
Monospecific stands of invasive plant species are found in nearly all known ecosystems and can cause permanent lasting ecosystem damage via deleterious effects in soils. These deleterious soil effects are a proposed mechanism which drives invasions by plants and are known to be influenced by kin recognition in plants. Uncovering whether invasive species utilize kin recognition to facilitate their own ecological persistence via soil conditioning will allow us to better understand the drivers of plant invasions and help combat them. In my master’s thesis, I examined the role of kin recognition and kin selection on soil effects. I grew groups of Potentilla recta in groups of maternal half-sibs or strangers to condition the soil. I then grew a second generation of plants in that conditioned soil to determine the impacts of soil conditioning effects on plant performance. I found soil conditioning by groups of plants affected the performance of a second generation of plants based on the relatedness of the conditioning plants. Further, these soil effects of conditioning selectively benefit future individuals of a subsequent generation based on their relatedness. Moreover, these soil effects only existed in soil that has not been sterilized, indicating these soil effects depended on soil microbes. / Thesis / Master of Biological Science (MBioSci) / Invasive plants form dense stands of same-species individuals that can cause lasting deleterious effects to the soil. These deleterious soil effects have been proposed as a mechanism driving plant invasions. In my master’s thesis, I examined the role of kin recognition and kin selection on soil effects. I first grew groups of Potentilla recta in groups of maternal half-sibs or strangers to condition the soil, and then grew a second generation of plants in that conditioned soil to determine the impacts on plant performance. I found that soil influenced by groups of related plants affect increased the performance of a second generation of plants, particularly if the second generation was related to the first. Moreover, these soil effects only existed in soil that has not been sterilized, indicating these soil effects depended on soil microbes. I found that these soil effects of conditioning selectively benefited future individuals of a subsequent generation based on their relatedness.
|
955 |
Oak regeneration: Impacts of prescribed fire and invasive speciesGoldsmith, Caleb Desmond 06 August 2021 (has links)
Across the central and eastern United States, upland oaks are experiencing regeneration complications. This thesis comprises two studies evaluating challenges in regenerating upland oaks. One study evaluates upland Quercus spp., Carya spp., and Acer rubrum L. response to prescribed fire and impacts on seedling growth and mortality. This study found prescribed fire promoted oak growth when canopy cover was < 77%. Oaks displayed lower percent mortality and higher resprout capacity after fire compared to red maple. The second study investigates impacts of Microstegium vimineum presence on Quercus alba L., Liriodendron tulipifera L., and Acer rubrum L. seedlings under different light and moisture environments. Microstegium vimineum presence decreased growth of both sweetgum and red maple; white oak was less impacted, likely because of its conservative growth strategy and high-water use efficiency. Oaks’ conservative growth strategy may offer more resiliency compared to its competitors in response to prescribed fire and Microstegium vimineum.
|
956 |
Hyperspectral Dimensionality Reduction via Sequential Parametric Projection Pursuits for Automated Invasive Species Target RecognitionWest, Terrance Roshad 09 December 2006 (has links)
This thesis investigates the use of sequential parametric projection pursuits (SPPP) for hyperspectral dimensionality reduction and invasive species target recognition. The SPPP method is implemented in a top-down fashion, where hyperspectral bands are used to form an increasing number of smaller groups, with each group being projected onto a subspace of dimensionality one. Both supervised and unsupervised potential projections are investigated for their use in the SPPP method. Fisher?s linear discriminant analysis (LDA) is used as a potential supervised projection. Average, Gaussian-weighted average, and principal component analysis (PCA) are used as potential unsupervised projections. The Bhattacharyya distance is used as the SPPP performance index. The performance of the SPPP method is compared to two other currently used dimensionality reduction techniques, namely best spectral band selection (BSBS) and best wavelet coefficient selection (BWCS). The SPPP dimensionality reduction method is combined with a nearest mean classifier to form an automated target recognition (ATR) system. The ATR system is tested on two invasive species hyperspectral datasets: a terrestrial case study of Cogongrass versus Johnsongrass and an aquatic case study of Waterhyacinth versus American Lotus. For both case studies, the SPPP approach either outperforms or performs on par with the BSBS and BWCS methods in terms of classification accuracy; however, the SPPP approach requires significantly less computational time. For the Cogongrass and Waterhyacinth applications, the SPPP method results in overall classification accuracy in the mid to upper 90?s.
|
957 |
Watching the Grass Grow: Effects of Habitat Type, Patch Size, and Land Use on Cogongrass (Imperata Cylindrica (L.) Beauv.) Spread On Camp Shelby Training Site, MississippiYager, Lisa Y 05 May 2007 (has links)
The purpose of this research was to increase understanding of ecology and control of cogongrass (Imperata cylindrica (L.) Beauv.) to assist with management of this invasive grass. To address different aspects of cogongrass management, I examined factors that affect spread of cogongrass, effects of cogongrass on native plant communities, and use of three native species to suppress cogongrass. Relative susceptibility of pine-bluestem and pine-shrub vegetation associations to vegetative encroachment and seed dispersal of cogongrass were evaluated. Vegetative encroachment into burned and unburned areas of these two vegetation associations also was measured. Effects of infestation size on vegetative growth of cogongrass and relationships between military activity and establishment and growth of cogongrass on military firing points were investigated. I also compared frequency of cogongrass infestation and vegetative growth rates for unpaved roads with different levels of traffic and maintenance. Native plant richness, diversity, and abundance were compared between cogongrass infestations and in uninfested adjacent areas for longleaf pine-bluestem and ruderal, cleared areas. Morella cerifera (L.) Small, Chamaecrista fasciculata (Michx.) Greene, and Panicum virgatum L. were tested for their ability to suppress cogongrass re-growth after treatment with a herbicide. Mean vegetative encroachment of cogongrass was < 2 m/yr for both habitat types regardless of burning. Vegetative encroachment was more than double in burned plots compared to unburned plots. Spikelets of cogongrass consistently dispersed farther into pine-bluestem (x¯ =17.3 m) forests compared to pine-shrub forests (x¯ = 9.4 m). Vegetative encroachment was not affected by size of infestation for cogongrass patches on firing points (x¯ < 1 m/yr) (P > 0.643). In areas of soil disturbance from military equipment, vegetative expansion rates of 7-10 m/yr were recorded. There was a positive relationship between military troop use and cogongrass establishment for one of the 2 years of the study (P = 0.023). Growth and establishment of cogongrass did not vary for unpaved roads with differing levels of maintenance and traffic (P > 0.173). Species diversity and abundance of herbaceous vegetation was less in cogongrass infestations compared to uninfested adjacent areas. Complete suppression of cogongrass was not evident for any of three native species tested.
|
958 |
Biomedical Imaging of Stem Cells Using Reporter GenesWang, Fangjing 17 May 2010 (has links)
No description available.
|
959 |
Design and Prototyping of a Three Degrees of Freedom Robotic Wrist Mechanism for a Robotic Surgery SystemLiu, Taoming January 2011 (has links)
No description available.
|
960 |
Limnetic Zooplankton Structure and The Impact of Invasion by an Exotic Cladoceran, Daphnia lumholtziPasko, Susan R. 02 July 2009 (has links)
No description available.
|
Page generated in 0.028 seconds