Competition between native perennial grasses and Bromus tectorum has been studied for many years. Recently, soil nutrients have been immobilized in an effort to preferentially inhibit growth of B. tectorum relative to native species. Most of this work has focused on soil N, but interactions with soil P are less studied and may be important as well. Additionally, although competitive effects and nutrient responses of several Centaurea spp. are well documented, data are lacking on the competitive effects that Centaurea virgata exerts on the establishment of native and exotic communities. A field experiment and a greenhouse experiment were conducted to evaluate influence of N and P on the native perennial bunchgrass Pseudoroegneria spicata in competition with B. tectorum and C. virgata. Chapter 2 describes the effects of nutrient immobilization and subsequent 2 x 2 factorial additions of N and P. Treatments were applied to transplanted individuals of the study species in monocultures and mixtures. Analysis of variance (ANOVA) was performed on shoot dry mass, soil water content, and physiological responses including photosynthetic rate, stomatal conductance, and transpiration. Results suggest that B. tectorum may be P-limited in certain circumstances, and that physiological activity of all species is subject to interactions between available N and P. In Chapter 3, I assess response of the study species to 2 x 2 factorial additions of N and P on a very low-nutrient soil in a greenhouse. Relative effects of different species mixtures on P. spicata are reported. I report ANOVA results of tiller number, leaf number, specific leaf area, shoot dry mass, root dry mass, and water addition. Results indicate that N and P co-limit P. spicata and B. tectorum, and to a lesser extent, C. virgata. B. tectorum showed the highest percentage response to fertilization. Land managers may be more successful establishing native grasses if they can minimize soil fertility.

Abandoned agricultural lands in the Intermountain West are plagued by dense, persistent non-native vegetation. Targeted restoration tools are required to remove the competitive advantage of these non-natives while also removing the soil legacies they leave behind. Activated carbon (AC) is one such tool, with the ability to disrupt the mechanisms of allelopathy, positive plant-soil feedbacks, and altered nutrient cycling commonly used by non-native species. Previous studies have shown the success of high concentrations of AC in native plant community restoration on a small scale. Here, our goals are twofold: first, to test AC effectiveness in restoring desirable plant communities on a larger scale, and secondly, to identify the primary mechanism, allelopathy versus microbial changes, through which AC impacts native and non-native species. A large scale AC treatment in Methow Valley, Washington tested the effectiveness of AC restoration at a large scale and tested five concentrations and two types of AC to determine lowest effective application. Following treatment, sites were monitored for vegetation cover for three years. The large-scale application produced similar results to the previous study at a 1000 g/m2 application rate, with a 28% increase in the ratio of desirable:undesirable species cover and a decrease to 25% undesirable species cover. However, the effectiveness of AC concentrations below 1000 g/m2 cannot yet be determined and may require a longer time scale and additional monitoring to assess restoration success. A greenhouse experiment was performed, which used native and non-native species common to the study site, grown in pairs in sterilized and live AC-treated soils to separate AC effects on allelopathy from that of microbial interactions. Both native and non-native species experienced a 25% decreased biomass in AC-treated live soils, with a minimal decrease in A- treated sterile soils for native species and no effect in AC-treated sterile soils for non-native species. Overall, AC live soils produced a positive effect on relative abundance; the ratio of native to non-native biomass was highest in AC-treated live soils. From these results, it is concluded that the primary pathway through which AC works is changes in the plant-microbial interactions of both native and non-native species.

Non-native invasive plant species can often have negative effects on native ecosystems, such as altered nutrient cycling, decreased habitat for wildlife, and outcompeting native plants. Around the Great Salt Lake (GSL), Utah, the invasive wetland grass Phragmites australis has become abundant in wetlands around the lake. Phragmites is replacing many native wetland plants provide important waterfowl habitat around the GSL. For successful management of Phragmites in GSL wetlands, it is important to know the current distribution of Phragmites, as well as areas that might be vulnerable to future invasion by Phragmites. To do this, we used multispectral aerial imagery to map the current distribution of Phragmites. We then created a model that statistically related the Phragmites distribution data to a suite of environmental predictor variables such as salinity, proximity to nutrient sources, or proximity to roads. Results from our model suggest that Phragmites is more likely to be found in wetland areas close to point sources of pollution, with lower elevations with prolonged inundation, and with moderate salinities. We used these results to identify areas around GSL that might be vulnerable to future invasion. Results from our study will assist wetlands managers in prioritizing areas for Phragmites monitoring and control by closely monitoring areas of prime Phragmites habitat.

Understanding of bio-nano-interfaces of living mammalian cells will benefit the identification of cellular alterations (e.g. nucleic acids, amino acids, biomechanics, etc.) due to external stimuli, the design of biomaterials (e.g. nanoparticles, nanotubes) and the investigation of the interaction between cells and bio-nano-interfaces (e.g. cell differentiation on 3D nanostructured materials). Analytical techniques can be applied to evaluate the chemical, physical, and mechanical properties of mammalian cells when exposed to such bio-nano-interfaces. In this study, non-invasive advanced spectroscopy techniques including atomic force microscopy (AFM) and Raman microscopy (RM), in conjunction with traditional biological methods are utilized to elucidate specific characteristic information for biological samples and how these property changes reflect the interaction with external stimuli. The focus of this dissertation is on the biophysical, biochemical and cytotoxic detection of mammalian cells interacting with bio-nano-interfaces, and this dissertation can be classified into three topics: biomechanics/cellular biopolymers measurement, bio-interfaces and nano-interfaces studies. For the topic of biomechanics/cellular biopolymers measurement, cellular biophysical and biomechanical properties could be used as differentiation markers to classify cellular differentiation. For the bio-interfaces part, it was observed that BRMS1 expression changed cellular biochemical and biomechanical properties, and the expressions of reactive oxidative species (ROS), apoptosis and cell viability of five types of cells displayed similar patterns over doxorubicin (DOX) incubation time. Secondly, A549 cells were treated with diesel exhaust particles (DEP) and resveratrol (RES) to study the effect of RES on the DEP-induced cells, and it was found that RES can alleviate DEP intervention on cellular structure and increase DEP-induced biomechanical and inflammatory changes. For the nano-interfaces topic, first we synthesized a hybrid nanoparticle with the multimodal properties of fluorescence imaging, Surface-enhanced Raman spectroscopy (SERS) detection and photothermal therapy (PTT) for single living cell analysis of epidermal growth factor receptor (EGFR) and specifically killed cancer cells with high EGFR expression. Additionally, to increase surface area, light-heat conversion efficiency and biocompatibility, we developed a silica coated nanoparticle conjugated with anti-human epidermal growth factor receptor 2 (HER2) antibody. Finally, three-dimensional TiO2 nanotubes with Au nanoparticles coating were synthesized and used to study trophoblast-derived stem-like cells growth on such 3D nanostructures.

The spread of invasive weeds continues to be a serious economic and environmental threat. Weed prevention has the potential to stop weeds before they become well established in an area conserving time, energy, and resources. Unfortunately, weed prevention is often overlooked. Weed Prevention Areas (WPAs) are a relatively new tool developed to help improve the application of weed prevention. They are cooperatively managed areas that focus on implementing prevention and early detection strategies at a community level. The purpose of this research was to establish baseline data that will be used to evaluate the overall effectiveness of the WPA concept, as well as to produce materials to assist individuals with the development of a WPA. Two rural communities, with new WPAs, were each paired with a non-WPA community for data collection purposes. On-the-ground GPS vegetation inventories were conducted to determine the initial abundance and distribution of selected invasive weed species. This information was then used to demonstrate how to prioritize species and sites within a WPA in order to utilize limited resources more efficiently. A mail-back survey was also conducted to evaluate landowners' current opinions and activities in regards to prevention and control. In general, weed prevention was viewed as an important part of integrated weed management, but fewer than half of all respondents applied prevention strategies on their property. The failure to implement prevention strategies was attributed to limited funding and resources, a lack of weed prevention knowledge, and a high level of perceived risk. The knowledge gained from this research was then used to create Step-By-Step Guidelines for Establishing a Weed Prevention Area. These Guidelines provide interested individuals the resources necessary to successfully organize a WPA in their community. In addition, four wildland weed mapping methods were evaluated to identify their strengths and weaknesses. There was no difference in the estimation of patch size or location between the buffered point, screen-drawn, and perimeter walked methods. In most situations, time and distance factors favor the selection of either the buffered point or screen-drawn method. If patch shape is an important consideration, the perimeter-walked or buffered point method should be selected.

Doctor of Philosphy (PhD) / This thesis describes the work carried out during four treks, each over 10-11 days, from 1400m to 5000m in the Nepal Himalaya and further work performed during several two-night sojourns at the Barcroft Laboratory at 3800m on White Mountain in California, USA. Nineteen volunteers were studied during the treks in Nepal and seven volunteers were studied at White Mountain. All subjects were normal, healthy individuals who had not travelled to altitudes higher than 1000m in the previous twelve months. The aims of this research were to examine the effects on sleep, and the ventilatory patterns during sleep, of incremental increases in altitude by employing portable polysomnography to measure and record physiological signals. A further aim of this research was to examine the relationship between the ventilatory responses to hypoxia and hypercapnia, measured at sea level, and the development of periodic breathing during sleep at high altitude. In the final part of this thesis the possibility of preventing and treating Acute Mountain Sickness with non-invasive positive pressure ventilation while sleeping at high altitude was tested. Chapter 1 describes the background information on sleep, and breathing during sleep, at high altitudes. Most of these studies were performed in hypobaric chambers to simulate various high altitudes. One study measured sleep at high altitude after trekking, but there are no studies which systematically measure sleep and breathing throughout the whole trek. Breathing during sleep at high altitude and the physiological elements of the control of breathing (under normal/sea level conditions and under the hypobaric, hypoxic conditions present at high altitude) are described in this Chapter. The occurrence of Acute Mountain Sickness (AMS) in subjects who travel form near sea level to altitudes above 3000m is common but its pathophysiology not well understood. The background research into AMS and its treatment and prevention are also covered in Chapter 1. Chapter 2 describes the equipment and methods used in this research, including the polysomnographic equipment used to record sleep and breathing at sea level and the high altitude locations, the portable blood gas analyser used in Nepal and the equipment and methodology used to measure each individual’s ventilatory response to hypoxia and hypercapnia at sea level before ascent to the high altitude locations. Chapter 3 reports the findings on the changes to sleep at high altitude, with particular focus on changes in the amounts of total sleep, the duration of each sleep stage and its percentage of total sleep, and the number and causes of arousals from sleep that occurred during sleep at increasing altitudes. The lightest stage of sleep, Stage 1 non-rapid eye movement (NREM) sleep, was increased, as expected with increases in altitude, while the deeper stages of sleep (Stages 3 and 4 NREM sleep, also called slow wave sleep), were decreased. The increase in Stage 1 NREM in this research is in agreement with all previous findings. However, slow wave sleep, although decreased, was present in most of our subjects at all altitudes in Nepal; this finding is in contrast to most previous work, which has found a very marked reduction, even absence, of slow wave sleep at high altitude. Surprisingly, unlike experimental animal studies of chronic hypoxia, REM sleep was well maintained at all altitudes. Stage 2 NREM and REM sleep, total sleep time, sleep efficiency and spontaneous arousals were maintained at near sea level values. The total arousal index was increased with increasing altitude and this was due to the increasing severity of periodic breathing as altitude increased. An interesting finding of this research was that fewer than half the periodic breathing apneas and hypopneas resulted in arousal from sleep. There was a minor degree of upper airway obstruction in some subjects at sea level but this was almost resolved by 3500m. Chapter 4 reports the findings on the effects on breathing during sleep of the progressive increase of altitude, in particular the occurrence of periodic breathing. This Chapter also reports the results of changes to arterial blood gases as subjects ascended to higher altitudes. As expected, arterial blood gases were markedly altered at even the lowest altitude in Nepal (1400m) and this change became more pronounced at each new, higher altitude. Most subjects developed periodic breathing at high altitude but there was a wide variability between subjects as well as variability in the degree of periodic breathing that individual subjects developed at different altitudes. Some subjects developed periodic breathing at even the lowest altitude and this increased with increasing altitude; other subjects developed periodic breathing at one or two altitudes, while four subjects did not develop periodic breathing at any altitude. Ventilatory responses to hypoxia and hypercapnia, measured at sea level before departure to high altitude, was not significantly related to the development of periodic breathing when the group was analysed as a whole. However, when the subjects were grouped according to the steepness of their ventilatory response slopes, there was a pattern of higher amounts of periodic breathing in subjects with steeper ventilatory responses. Chapter 5 reports the findings of an experimental study carried out in the University of California, San Diego, Barcroft Laboratory on White Mountain in California. Seven subjects drove from sea level to 3800m in one day and stayed at this altitude for two nights. On one of the nights the subjects slept using a non-invasive positive pressure device via a face mask and this was found to significantly improve the sleeping oxyhemoglobin saturation. The use of the device was also found to eliminate the symptoms of Acute Mountain Sickness, as measured by the Lake Louise scoring system. This finding appears to confirm the hypothesis that lower oxygen saturation, particularly during sleep, is strongly correlated to the development of Acute Mountain Sickness and may represent a new treatment and prevention strategy for this very common high altitude disorder.

Thesis (M.S. zoology)--Washington State University, December 2007. / Includes bibliographical references (p. 24-26).

L'hypoventilation alvéolaire chronique est considérée comme un marqueur d'évolution péjorative de différentes pathologies respiratoires. Cependant, son rôle physiopathologique dans différentes dysfonctions systémiques n'a pas été étudié de manière convaincante. Cette thèse avait pour but d'investiguer les conséquences de l'hypoventilation alvéolaire modérée au cours de l'insuffisance respiratoire chronique restrictive et les effets de son traitement par ventilation non-invasive.<br /> Nous avons montré que des patients affectés d'un syndrome obésité-hypoventilation (SOH) avaient une fonction endothéliale plus sévèrement altérée et une inflammation systémique plus importante que les patients obèses simples. La PaCO2 était corrélée à la dysfonction endothéliale (Borel et coll, manuscrit en préparation). Nous avons observé que la proportion d'hypoventilation en sommeil paradoxal, chez les sujets SOH, était associée à une réponse ventilatoire au CO2 abaissée et une somnolence diurne excessive. Pour la première fois, nous avons constaté que la ventilation non invasive nocturne améliorait la vigilance diurne objective (Chouri-Pontarollo et coll, Chest 2007). Nous menons actuellement la première étude randomisée du traitement des patients porteurs d'un SOH par VNI versus observation pendant un mois. L'analyse intermédiaire montrait qu'un mois de VNI nocturne chez les patients SOH améliorait la PaCO2 diurne, la capacité pulmonaire totale, la structure du sommeil, cependant aucun paramètre cardiovasculaire et métabolique n'était modifié. <br />Chez des patients insuffisants respiratoires chroniques pariéto-restrictifs, la VNI utilisée au cours d'un exercice aigu, augmentait la ventilation et améliorait la tolérance à l'effort (Borel et coll, Resp Med 2008). Chez ces mêmes patients, un réentrainement à l'effort sous VNI n'apportait pas de bénéfices additionnels par rapport à un réentrainement en ventilation spontanée sauf chez les patients les plus sévères. Ces derniers, amélioraient leur périmètre de marche et leur qualité de vie. Leur fatigue en particulier était améliorée s'ils s'étaient réentraînés sous VNI (Borel et coll, Am Journal of physical med and rehab, 2008, soumis). <br />Enfin, nous avons analysé l'impact des fuites intentionnelles des masques de VNI sur la performance des appareils de VNI bi-pressionnels. L'augmentation des fuites intentionnelles diminuait les capacités des appareils à atteindre et maintenir la pression de consigne. Ceci pouvait conduire à une diminution du volume délivré au patient, en particulier pour des fuites intentionnelles supérieures à 40 L.min-1 à 14 cm H2O de pression (Borel et al, Chest, sous presse). <br /> Conclusion : L'hypoventilation alvéolaire chronique peut-être considéré comme un déterminant physiopathologique de la dysfonction endothéliale, de l'inflammation, de la somnolence, et de l'intolérance à l'effort. La VNI, utilisée au cours des efforts, permet d'améliorer les capacités d'exercice et la qualité de vie des patients insuffisants respiratoires restrictifs les plus sévères. Malgré les limites technologiques des appareils de VNI bi-pressionnels utilisés actuellement, la VNI corrige l'hypoventilation alvéolaire des patients SOH, cependant les effets sur l'inflammation, la dysfonction endothéliale restent incertains à cours et long terme chez ces sujets obèses.

Mettre en oeuvre un retour d'effort pour un système robotique dédié à la chirurgie mini-invasive impose d'adresser deux difficultés principales. La première est d'ordre métrologique, puisqu'il est technologiquement très difficile de procéder à une mesure directe de l'interaction distale à l'intérieur du patient, tout en respectant les contraintes de stérilité et d'encombrement. La seconde concerne le contrôle d'interactions dont la géométrie et la dynamique sont fortement variables et mal connues (contacts avec des organes, le chirurgien, ou d'autres instruments) dans un contexte particulier où la contrainte cinématique induite par le passage des instruments par un point fixe ne permet pas l'asservissement de toutes les composantes du torseur d'interaction.<br />La réponse apportée à ces questions prend ici la forme d'un système robotique bâti autour :<br />- d'un bras compact de cinématique sphérique ;<br />- d'un capteur d'efforts placé à l'extérieur du patient permettant une estimation fine des interactions distales ;<br />- d'une commande en effort dont la passivité est garantie pour toutes les interactions ; celle-ci est déclinée selon plusieurs modes (retour explicite, commande en impédance, téléopération à retour d'efforts).<br /><br />L'ensemble des propositions méthodologiques est validé de façon systématique sur un prototype de laboratoire développé dans le cadre de ce travail. Les expériences incluent des validations in vivo sur animal, depuis des tâches élémentaires jusqu'à l'utilisation du prototype comme "main gauche" pour une opération de cholécystectomie.

<p>Abstract</p><p>In Oneida Lake, New York, USA, three species of amphipods are present: Hyalella azteca is native, Gammarus fasciatus is invasive and was first observed sometime before 1940 and Echinogammarus ischnus was introduced in 2001 in shallow water. The purpose of this study was to investigate the spatial and temporal abundance of amphipods in Oneida Lake. In the Great Lakes, the invasive E. ischnus has outcompeted G. fasciatus and this was also expected to be occur in Oneida Lake. Quantitative field sampling of transects that extended from the shore to deeper water (3.8 m) at six sites around Oneida Lake showed that the abundance of all amphipod species had a positive correlation to the abundance of zebra mussels (Dreissena polymorpha). Echinogammarus ischnus were observed at low densities (mean, 18 no./m2) in shallow water (<0.6 m) areas with cobbles covered with zebra mussels, whereas just a few individuals were found in deep water. At all depths, G. fasciatus were found at high densities (mean 950 no./m2), and H. azteca were present at low densities (mean 77 no./m2). The main factor limiting E. ischnus and its coexistence with G. fasciatus is the lack of favourable habitat i.e. too few cobble areas and too much Cladophora spp. and other macrophyte species growing in the lake. In addition, exposure of shallow water habitats every fall and winter as a consequence of water level manipulations produces unfavorable habitat for E. ischnus.</p> / <p>Sammanfattning</p><p>I sjön Oneida Lake, New York, USA, finns tre arter av märlkräftor (Amphipoda): Hyalella azteca är naturligt förekommande i sjön, Gammarus fasciatus hittades för första gången någon gång före år 1940 och Echinogammarus ischnus hittades för första gången 2001 på grunt vatten. Syftet med studien var att undersöka märlkräftornas utbredning och abundans över tid i Oneida Lake. I de Stora sjöarna (the Great Lakes) i Nordamerika har den invaderande E. ischnus konkurrerat ut G. fasciatus och samma sak förväntades att finna i Oneida Lake. I fält togs kvantitativa stickprover i transekter från strandlinjen och ut till djupt vatten (3,8 m), dessa visade att samtliga märlkräftsarter hade en positiv abundans korrelation med zebra musslor (Dreissena polymorpha). E. ischnus hittades i låga densiteter (medel 18 st/m2) på stenar täckta med zebra musslor på grunt vatten (<0,6 m) och endast ett fåtal individer hittades på djupt vatten. I Oneida Lake på alla djup hittades G. fasciatus i höga densiteter (medel 950 st/m2) medan H. azteca endast fanns i låga densiteter (medel 77 st/m2). Största anledningen till E. ischnus begränsning till samexistens med G. fasciatus är avsaknaden av gynnade habitat i sjön, det vill säga för få områden med stenar, samt att det växer för mycket alger (Cladophora spp.) och andra växter i sjön vilket missgynnar E. ischnus. Även vattennivåreglering under höst och vinter är ogynnsam för E. ischnus, då habitat på grunt vatten blir exponerande.</p>