The Allium tricoccum Aiton (ramps, aka wild leeks), a native spring ephemeral, is a cultural keystone species in Appalachia, a mountainous physiographic region encompassing 205,000 square miles of the eastern United States. People in Appalachia have long harvested ramps in the wild. However, growing demand for the plant in and outside the region has increased harvesting, resulting in threats to native populations. Agroforestry cultivation techniques and technical support for sustained-yield forest farming practices are needed to conserve ramps and meet increasing demand. Various techniques for assessing suitable production practices for ramps were explored in this dissertation, particularly examining best-suited ramp ecotypes, mycorrhizal treatment, and habitat suitability determination. In the first study, bulbs and seeds from diverse Appalachian locations were gathered and transplanted to a common experimental site to investigate the effects of different ramp ecotypes on growth, survival, and stress responses. Plant characteristics and stress measurements were recorded before transplantation and post-transplantation assessments. Specifically, the study investigated the germination rate of three ramp seed ecotypes and the growth, survival, and stress responses of eight native ramp bulb ecotypes and three commercially obtained seedling samples. Results indicated that above-ground growth, survival, and stress response on the ramp ecotypes differed significantly. The second study explored the impact of mycorrhizae on ramps and was evaluated by assessing the impact of Arbuscular Mycorrhizal Fungi (AMF) inoculation on Allium tricoccum. Four measurements, collectively referred to as parameter categories, were assessed. These included measures of 1) above-ground plant growth: leaf length, and leaf width; 2) stress measurement: transplant stress after a few days of transplant, and photosynthetic performance stress after a year of transplant; 3) survival analysis; and 4) mycorrhizal colonization rate. For each parameter category, three treatment comparison categories were conducted: 1) Positive control treatments: bulbs were planted from their native environment without treatment; 2) Negative controls: bulbs were treated with fungicide before planting to eradicate existing AMF in roots; and 3) The test group: bulbs were inoculated with commercial AMF (Atriva 500). Results indicated that mycorrhizal inoculation could increase ramp leaf length (P≤0.03). However, the impact varied by ecotype, highlighting the importance of considering local environmental conditions and ramp ecotype. Mycorrhizal inoculation did not impact ramp growth at the seedling stage. Mycorrhizal treatment increased the transplanted ramp's survival and stress tolerance (P≤0.001). The third study used multi-criteria decision-making (MCDM), the Analytic Hierarchical Process (AHP), and weighted linear combinations to model suitable habitats for ramps production. Ten habitat criteria were chosen (including five soil properties, three topographic parameters, and two land use properties) to assess the potential for growing ramps in seven counties in Virginia, West Virginia, Pennsylvania, and North Carolina. The percentage of highly suitable areas for ramps production in the studied counties ranges from 21.5% in Haywood County to 49.6% in Macon County. Similarly, moderately suitable areas range from 36.7% in Macon County to 54.5% in Lawrence County. Ground truthing was performed to validate the model. Ramp patch locations within each county were geocoded in the final suitability maps. Existing ramp patches were within the model's estimate of moderate to high site suitability ranges, suggesting the model is valid. Results of the study suggest that site suitability modeling could be useful for producers interested in growing ramps in forest farm settings across Appalachia. / Doctor of Philosophy / The ramp, also known as the wild leek, is an important food, medicinal and cultural resource for the people of Appalachia. However, increasing demand for ramps beyond this region has led to over-harvesting and threatens the plant's native populations. Appropriate cultivation techniques and technical support for sustained-yield forest farming practices are needed to conserve ramps and meet growing demand. This dissertation explores various techniques for assessing suitable production practices for ramps, including examining ramp ecotypes, mycorrhizal treatments, and habitat suitability determination. The first study evaluated the ecotypic variation among ramps collected from different geographic regions and their impact on plant performance. Ramp ecotypes displayed differences in above-ground growth, survival, and stress response. The second study examined the impact of mycorrhizae on ramps and found that mycorrhizal inoculation can increase ramp leaf length and survival and stress tolerance of transplanted ramps. However, this impact varied by ecotype, highlighting the importance of considering local environmental conditions and ramp ecotype. The third study involved developing a model to identify suitable habitats for growing ramps. The model was tested for seven counties across Virginia, West Virginia, Pennsylvania, and North Carolina. The percentage of land predicted as highly suitable for ramps production ranged from 21.5% in Haywood County, NC, to 49.6% in Macon County, NC. Moderately suitable lands ranged from 36.7% in Macon County, NC to 54.5% in Lawrence County, PA. Ground truthing confirmed the model's accuracy as geocoded existing ramp patch locations fell within the estimated suitable ranges. Site suitability modeling could be useful for people interested in growing ramps in forest farm settings across Appalachia. Overall, this research provides insights into best practices for ramp cultivation that help conserve a cultural keystone species and meet the growing demand for ramps.

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Highway safety has been a priority for many years now. A system-wide crash analysis is a practical solution when only a limited budget is available for improving safety of highways. A systematic approach, in contrast to a hotspot analysis, allows for a widespread installation of lower-cost countermeasures across the highway network. This study focuses on the safety evaluation of a particular facility type, urban freeway off-ramps, in terms of its geometric and traffic characteristics. 144 off-ramp segments in Richmond, VA were evaluated based on the crash data available from 2011 to 2015. A statistical model was developed that relates crashes to the geometric and traffic characteristics of each off-ramp segment. A test for independence was performed to identify if a statistically significant difference existed between type of collision and severity of crashes with respect to ramp geometry and traffic control. Significant geometric and traffic variables were then identified from the model and independence test to assist in the selection of low-cost countermeasures. AADTs of both freeways and off-ramps were found to be the most statistically significant variables. Installation of advance warning signs for better traffic management near the freeway diverge area and clearing roadsides of fixed objects to reduce rear-end collisions are low-cost solutions for crashes on urban off-ramps in the study area. The results of this study demonstrate an approach to safety evaluations that could support transportation planners and agencies in identifying system-wide locations to install or apply appropriate low-cost countermeasures. / Master of Science

Gleich einem Etikett dient die N-Glykokosylierung vom Ribosom neu synthetisierter Proteine durch die Oligosaccharyltransferase (OST) bei der kotranslationalen Translokation in das Endoplasmatische Retikulum (ER) als Startpunkt vielschichtiger Prozessierungen. Bisher fehlte der strukturelle Nachweis, dass die OST als mit dem Ribosom assoziierten Membranprotein (RAMP) Bestandteil des auf dem proteinleitenden Kanal, dem Sec61-Komplex, basierenden Translokons ist. In dieser Arbeit berichten wir von der kryoelektronenmikroskopischen 3D-Struktur eines definierten OST-Sec61-Ribosom-Komplexes aus Saccharomyces cerevisiae bei 15,4 Å Auflösung. Dazu wurden die Komponenten (OST, Sec61 und Ribosomen mit naszierender Proteinkette) affinitätschromatographisch gereinigt und das Bindungsverhalten mit 80S-Ribosomen in vitro untersucht. Die OST band mit einer KD von 12,8 nM hochaffin und spezifisch an den bekannten Sec61-Ribosomen-Komplex. Dieser in vitro rekonstituierte trimere Komplex zeigte eine neuartige eng an das Ribosom anschließende Translokonstruktur mit zwei bisher unbekannten ribosomalen Verbindungen, einer einzigen dezentralen porenförmigen Vertiefung und zusätzlichen luminalen Bereichen. Durch das Docken eines Sec61-Homologs in einer alternativen Bindeposition sowie das Docken eines Stt3p-Homologs (der katalytischen Untereinheit der OST) und mit Hilfe der mittels (Kryo-)Negativkontrastierung gewonnenen 3D-Struktur der OST konnten Hybridmodelle erstellt werden. Daraus wurde unter Einbeziehung von bekannten molekularbiologisch gewonnenen Interaktionsdaten das 3D-Modell eines aktiven Ribosomen-gebundenen OST-Sec61-Translokons entwickelt. / Like a label, N-glycosylation by the oligosaccharyltransferase (OST) of newly synthesized proteins emerging from the ribosome while being cotranslationally translocated into the endoplasmic reticulum (ER) provides a starting point for a multitude of processes. Hitherto no structural proof has been presented, that the OST as a ribosome associated membrane protein (RAMP) is a constituent of the translocon, based at its core on the protein conducting channel (Sec61-complex). In this work we report on the 3D-structure of a defined OST-Sec61-ribosome complex from Saccharomyces cerevisiae by cryo-electron microscopy at 15.4 Å resolution. Thereto, the components (OST, Sec61, ribosome nascent chain complexes) have been purified by affinity chromatography and the binding of 80S-ribosomes has been checked in vitro. The OST bound with high affinity by a KD of 12.8 nM specifically to the established Sec61-ribosome complex. This trimeric complex reconstituted in vitro exhibits a new kind of tightly bound ribosomal translocon showing two hitherto unknown connections to the ribosome, a single off-center pore-like indentation and an additional luminal domain. By docking of a Sec61 homologue at an alternative binding position plus the docking of a Stt3p homologue (the catalytic subunit of the OST) and by means of the 3D-structure of the OST using the (cryo-)negative staining technique, hybrid models could be created. Consequently, integrating known interaction data from molecular biology experiments has been used to develop a 3D-model of an active ribosome-bound OST-Sec61-translocon.

Laser-plasma accelerators are of great interest because of their ability to sustain extremely large acceleration gradients, enabling compact accelerating structures. Laser-plasma acceleration is realized by using a high-intensity short pulse laser to drive a large plasma wave or wakefield in an underdense plasma. This thesis considers the effect of axial plasma density upramps on laser wakefield acceleration. Theoretical groundwork shows that tapered plasma channels can be used to mitigate one of the main limitations of laser plasma acceleration, that is, dephasing of an electron beam with respect to the plasma wave. It is shown that it is possible to maintain an electron bunch at constant phase in the longitudinal electric fields of the laser wake field. This leads to an increased energy gain of an electron trapped in the wakefield. The required shape of the density slope is difficult to implement in experiments. Therefore, a linear density ramp is also considered which is predicted to also increase the energy gain beyond that possible in a uniform density plasma. Towards an experimental implementation it was studied how a suitable gas density profile can be established in a capillary. This was done employing simulations using the computational fluid dynamics tool kit OpenFoam and comparing these to measurements of the axial density profile based on Raman scattering. It was demonstrated that a linear density ramp could be established by applying different pressures on the capillary gas inlets. The dependence of the density profile on the capillary parameters, such as, capillary diameter and length and inlet diameter were also studied. The results of the simulations and the measurement showed excellent agreement and demonstrate that approximately linear density ramps can be generated by flowing gas along a capillary of constant cross-section Laser wakefield acceleration in plasmas with longitudinally varying density was investigated in an experiment at the Astra Laser at Rutherford Laboratories. The experiment utilised ionisation injection in order to operate in the mildly non-linear regime of laser-wakefield acceleration. The measured electron energies agree well with the theoretical predictions. It was demonstrated that an increase in the energy gain can be obtained by driving the accelerator in a ramped plasma, the electron spectrum is more narrow and the injected charge increases significantly. Measurements of the X-ray spectrum emitted by the betatron motion of the accelerated electron bunch allowed the transverse radius of the bunch to be deduced. These measurements showed that retrieved electron bunch radius is inversely proportional to the longitudinal density gradient, that is a plasma density upramp (downramp) has a decreased (increased) electron bunch radius.

Ramp metering, one of the most effective solutions for improving motorway traffic flows, is playing increasingly important role in traffic management systems. Because of its capability to handle nonlinear and non-stationary problems, fuzzy logic based ramp metering algorithms have been always considered as an extremely suitable control measures to handle a complex nonlinear traffic system. This thesis proposes a genetic fuzzy approach to design a traffic-responsive ramp control algorithm for an isolated onramp. For a local ramp meter algorithm, the problem could be described as the inflow optimization of on-ramp, based on the evaluation of motorway traffic condition. If the inflow of on-ramp is considered as the decision variable, the ramp control problem could be treated as a nonlinear optimization problem of maximizing the evaluation function. The adaptive genetic fuzzy approach is actually a control approach to maximize the inflow of on-ramp under the restriction of evaluation function. In this thesis, a well-known fuzzy logic based ramp metering algorithms developed by Bogenberger is introduced and implemented with an on-ramp congestion model of Constellation Drive Interchange in a stochastic microscopic traffic simulator, Aimsun. To improve the performance of fuzzy control system, genetic algorithm is applied to tune the parameterized membership function of each fuzzy input to maintain the flow density of motorway blow the estimated congestion density. The performances of the genetic fuzzy logic control ramp metering are compared with FLC (fuzzy logic control) ramp metering by means of the percentage change of TTT (Total Travel Time) based on no control condition in Aimsun. The simulation results show the genetic fuzzy ramp metering has a more significant improvement on TTT and more strong stability to maintain system flow density than FLC ramp metering.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Apesar da importÃncia do saneamento ambiental para o bem-estar do homem e para a conservaÃÃo dos recursos naturais, uma grande parcela da populaÃÃo mundial nÃo tem acesso aos serviÃos bÃsicos de saneamento. A disposiÃÃo no solo hà muitos anos mostra-se como opÃÃo para tratamento e pÃs-tratamento de efluentes domÃsticos, sendo que a recusa por grande parte da populaÃÃo reside da ignorÃncia e da falta de informaÃÃes adequadas quanto Ãs formas de reÃso que podem ser oferecidas. O escoamento superficial mostra-se simples quanto à construÃÃo e operaÃÃo, bem como a produÃÃo vegetal obtida com esse tipo de sistema. Foi testada a grama Tifton 85(Cynodon sp), pois possui grande adaptaÃÃo a condiÃÃes de altas concentraÃÃes de nutriente e umidade, mostrando-se como opÃÃo viÃvel para cultivo em rampas de escoamento superficial. O experimento foi realizaÃÃo no Centro de ReÃso da CAGECE localizado na EstaÃÃo de Tratamento de Efluentes da cidade de Aquiraz, CearÃ. Foram construÃdas trÃs rampas de escoamento superficial com inclinaÃÃes diferentes, 2%, 4% e 6% com 30 metros de comprimento e 10 metros adicionais na rampa de 6% de inclinaÃÃo. O lÃquido aplicado nas rampas era esgoto sanitÃrio tratado, proveniente de lagoa de maturaÃÃo. As taxas de aplicaÃÃo de esgoto testadas foram 0,2m3/m.h, 0,3 m3/m.h e 0,4 m3/m.h. Avaliou-se a capacidade do sistema em remover nutrientes, nitrogÃnio e fÃsforo, bem como matÃria orgÃnica. Com a realizaÃÃo de anÃlises quantitativas foi possÃvel determinar qual inclinaÃÃo permitia maior remoÃÃo e em qual vazÃo de operaÃÃo. Para taxas de 0,2m3/m.h, 0,3 m3/m.h a rampa com 2% de inclinaÃÃo alcanÃou 57,65% e 57,11% de remoÃÃo de matÃria orgÃnica respectivamente. Em termos de remoÃÃo de nitrogÃnio a rampa com 6% teve melhor desempenho. O sistema tambÃm apresentou remoÃÃes significativas de microalgas, avaliados em termos de clorofila-a. Em todos os aspectos analisados, o sistema melhorou a qualidade final do efluente, mostrando-se como alternativa viÃvel, com tÃcnica simples e barata compatÃvel com a realidade econÃmica do nordeste brasileiro

This work investigates how to improve wind power predictions using observational wind speed data. Measurements from ultrasonic anemometers (sonics) are available from five of the 22 wind energy turbines at the analysed wind farm in Beeskow, Germany (52°11’48'N, 14°13’E). In addition, measurements from a vertically pointing Doppler lidar (DL) at the Meteorological Observatory Lindenberg - Richard Aßmann Observatory located at a distance of 6 km from the wind farm are evaluated. The LoadManager® tool, developed by LEMSoftware, Leipzig, is used to perform wind power predictions based on different input data for forecasting horizons of 15 min and 30 min. Though wind power predictions have consistently improved in the last decade, persistent reasons for remaining uncertainties are sudden large changes in wind speed, so-called ramp events. The occurrence of ramp events at the wind farm has been investigated. Results on the seasonality of ramp events and their diurnal cycle are presented for multiple ramp detection thresholds. Ramps were found to be most frequent in March and April and least frequent in November and December. Furthermore, ramp events occur more frequently during the day than during the night and for most ramp detection thresholds up-ramp events are slightly more frequent than down-ramp events. For further analysis, the wind power prediction tool is fed with different wind velocity input data. The reference wind power predictions are based on data from a numerical weather prediction (NWP) model. Power predictions using observed wind speed data (DL, sonics) are compared to these reference predictions and evaluated according to two metrics: (i) the absolute difference between the observed and predicted power generation and (ii) the costs incurred due to necessary balancing services. It was found that, (i) the absolute power deviation can be reduced significantly compared to the reference by using power prediction setups based on sonic data. This improvement is even greater during ramp time steps. Power predictions based on the available DL data do not improve the absolute power deviation for the entire data set, albeit they do provide an improvement during down-ramp events. Considering (ii) incurred balancing costs, all power prediction setups based on observational data reduce the balancing costs compared to the reference. Sonic-based configurations yield 75-80% lower balancing costs than the reference and the DL-based setup results in 20% lower balancing costs. / Diese Arbeit untersucht, wie sich Windleistungsprognosen mit Hilfe von Windmesswerten verbessern lassen. Messungen von Ultraschallanemometern (sonics) an Gondeln von fünf der 22 Windenergieanlagen des untersuchten Windparks Beeskow, Deutschland (52°11’48'N, 14°13’E), sind verfügbar. Weiterhin sind Messungen des vertikalgerichteten Doppler Lidars (DL) am Meteorologischen Observatorium Lindenberg - Richard Aßmann Observatorium des DWD verfügbar, welches sich in einer Entfernung von 6km zum Windpark befindet. Das Programm LoadManager® der Leipziger Firma LEM-Software wird für Windleistungsprognosen mit verschiedenen Eingangsdaten für die Prognosezeiträume +15 min und +30min verwendet. Die Qualität von Windleistungsprognosen hat sich in den letzten zehn Jahren stetig verbessert. Unsicherheiten bleiben z.B. sogenannte Windrampen, schnelle, starke Änderungen der Windgeschwindigkeit. Das Auftreten von Windrampen am Windpark Beeskow wurde untersucht und die Ergebnisse werden für verschiedene Rampengrenzwerte vorgestellt. Am häufigsten treten Windrampen im März und April auf und am seltensten treten sie im November und Dezember auf. Außerdem wurden Windrampen häufiger tagsüber als nachts festgestellt. Für die meisten Rampengrenzwerte wurden etwas mehr Leistungsanstiege ('up-ramps') als Leistungsrückgänge ('down-ramps') gefunden. Für weitere Untersuchungen wurden Windleistungsprognosen mit verschiedenen Windgeschwindigkeitsdatensätzen durchgeführt. Als Referenz gelten Windleistungsprognosen auf Basis von Daten numerischer Wettervorhersagemodelle. Windleistungsprognosen auf Basis von Messwerten (sonics, DL) werden mit dem Referenzmodell verglichen und entsprechend zweier Metriken bewertet: (i) der absoluten Abweichung zwischen der vorhergesagten und beobachteten Stromerzeugung und (ii) der für Abweichungen anfallenden Regelenergiekosten. Die Ergebnisse zeigen, dass (i) die absolute Abweichung verglichen mit der Referenz signifikant reduziert werden kann, in dem man Messwerte von sonics für die Leistungsprognose verwendet. Dabei ist die Verbesserung während Windrampen größer als für den gesamten Datensatz. Windleistungsprognosen auf Basis von DL-Daten zeigen keine Verbesserung der Abweichungen für den gesamten Datensatz, jedoch eine signifikante Verbesserung während Leistungsrückgängen. Betrachtet man (ii) die anfallenden Regelenergiekosten, resultieren alle auf Messwerten basierenden Leistungsprognosen in einer Reduktion der Kosten verglichen mit dem Referenzmodell. Windleistungsprognosen auf Basis der Gondelmessungen reduzieren die Regelenergiekosten um 75-80% und Windleistungsprognosen auf DL-Basis ergeben im Mittel etwa 20% niedrigere Regelenergiekosten.

Merging from on-ramps to mainline traffic is one of the most challenging driving maneuvers on freeways. The challenges are further heightened for older drivers, as they are known to have longer perception-reaction times, larger acceptance gaps, and slower acceleration rates. In this research, VISSIM, a microscopic traffic simulation software, was used to evaluate the influence of the aging drivers on the operations of a typical diamond interchange. First, drivers were recorded on video cameras as they negotiated joining the mainline traffic from an on-ramp acceleration lane at two sites along I-75 in Southwest Florida. Several measures of effectiveness were collected including speeds, gaps, and location of entry to the mainline lanes. This information was used as either model input or for verification purposes. Two VISSIM models were developed for each site – one for the existing conditions and verification, and another for a sensitivity analysis, varying the percentage of older drivers and Level of Service (from A to E), to determine their influence on ramp operational characteristics. According to the results, there was a significant difference in driving behavior between older, middle-aged, and younger drivers, based on the measures of effectiveness analyzed in this study. Additionally, as the level of service and percentage of older adult motorists increased, longer queues were observed with slower speeds on the acceleration lanes and the right-most travel lane of the mainline traffic.