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<p> Thellungiella salsuginea (also known as T. halophila), is an emerging model species for studies of plant tolerance to osmotic stress. Currently, Thellungiella plants originating from two geographical locations are being developed for research. Yukon Thellungiella is native to the saline and alkaline soils of the Yukon Territory, Canada. The seeds in this study were collected at the Takhini Salt-Flats near Whitehorse, YT, a sub-arctic and semi-arid region. Plants from the Yukon have been proposed to be a suitable species to study plant tolerance to salinity, cold temperatures, and water deficits. Shandong Thellungiella is native to the saline coast of north-eastern China in Shandong Province where the climate is temperate and affected by summer monsoons. This plant has been proposed as an ideal model for the study of salt tolerance mechanisms but is reported to show little drought tolerance.</p> <p> An objective of this study was to compare Yukon and Shandong Thellungiella plants with respect to their ability to withstand water deficits. Plants were grown simultaneously in controlled environment chambers where watering was withheld until plants visibly wilted. Wilting occurred at a leaf relative water (RWC) content of about 50-60% and then turgor was restored by re-watering. In a second experiment plants allowed to wilt and recover once were then subjected to a second wilting and recovery cycle. The third experimental approach tested the survival capacity of plants after experiencing a wilting episode where leaf RWC dropped to about 30%.</p> <p> With the first drought simulation treatment, both Yukon and Shandong plants took about 6 days to wilt when watering was stopped. After re-watering and recovery, the Yukon plants subjected to a second drought episode took almost two days longer to wilt while the similarly treated Shandong plants showed no change in the days taken to wilt. This indicates that Yukon plants show improved tolerance to stress after a single exposure to a water deficit. Yukon plants were also able to grow and complete their life cycle following exposure to severe water deficit treatment whereas Shandong plants died. Measurements of solute potential showed that the Yukon plants re-established turgor at a lower solute potential of -2.06 +/- 0.03 MPa following recovery from a second drought treatment suggesting that this plant can undergo osmotic adjustment. No evidence of osmotic adjustment was observed for Shandong Thellungiella.</p> <p> Gas chromatography/mass spectrometry (GC/MS) was used to identify the metabolites associated with Thellungiella leaves recovering from water deficits relative to those from unstressed, well-watered controls. For comparison, metabolite profiles were also prepared from leaves of plants harvested at a Yukon field site during a dry year (2003) and a year of higher than normal rainfall (2005). The data was analyzed to identify treatment/sample-specific patterns using ANOVA to test for significance among quantitative and qualitative changes for individual metabolites. Significant changes were then subjected to hierarchical cluster analysis (HCA) and principal component analysis (PCA). Using ANOVA and HCA, we were able to identify the most likely metabolite candidates contributing to the superior tolerance of Thellungiella, and their linkages between broad spectrums of metabolites. Using PCA we were able to assign clusters to the individual plant treatments for each plant source, and identify the most important components contributing to these clusters. Of the ca 289 components detected, only a small subset of components underwent statistically significant changes in abundance. Most of the drought-stress related changes were attributed to sugars: hexoses and disaccharides. Sugars accumulating in the more drought-tolerant Yukon plants and in a dry field season included fructose, glucose and galactose. Of the sugar alcohols, only myo-inositol showed patterns of interest in view of its enrichment in tissues showing superior tolerance to low water conditions. Similar patterns were also shown by the organic acid, threonic acid.</p> <p> A complementary approach was used to characterize metabolic traits associated with exposure to cold temperatures. In this study, a higher content of proline and citrate distinguished plants exposed to cold temperatures irrespective of whether the plants were in cabinets or in the field. Proline content, however, did not show drought-responsive accumulation under any drought treatment tested. As such, by comparison with the drought-stress data we can identify possible stress-specific signatures among metabolites undergoing changes. The study of stress-responsive traits could help develop a better understanding of plant systems and their response to specific environmental conditions.</p> / Thesis / Master of Science (MSc)

This dissertation brings new causal evidence on three topics in education and health. In the first chapter, I study how in-utero exposure to floods affects the education and health outcomes of individuals. I focus on the 1982-1983 El Niño event in Peru to exploit a natural experiment. I assess the impacts of plausible and exogenous in-utero exposure to excess rainfall on education achievement at adulthood. I find that individuals exposed in-utero to the 1982-1983 El Niño floods, have less chances to have completed primary education at adulthood with different effects by place of residence and gender. In the second chapter, I study how a low-cost face-to-face intervention, that exposed senior-year high school students to female role models affects career preferences and reduces the gender preference gap for STEM programs in Peru in a randomized controlled trial. I find that exposure to role models increased preference for engineering majors only for those girls in the top math ability quartile; and that the effect was stronger for those who reside geographically close to the role models' university. Finally, in the third chapter, I investigate how to optimally allocate students to academic programs. I evaluate external signals of ability transmitted to students by academic probation rules in Peru using a regression discontinuity design. The analysis suggests that academic probation is associated with higher drop-out rates from programs and a deterioration in subsequent academic performance. I conclude that in a society with predominant gender norms, signals of ability could aid to the retention of only qualified students in selected programs with further implications on aggregate productivity and the allocation of talent. / Doctor of Philosophy / This study sought to understand how exposure to different adverse events in life affects individuals' decision choices. I focus on a developing country, Peru, where returns to education are high and investment in human capital can improve individuals' lives. In the first chapter, I study how prenatal exposure to extreme weather conditions (i.e. the 1982-1983 El Niño floods in Peru) affected the education achievement of those individuals when they were older. This adverse and unpredictable event, affecting the evolution of babies while in-utero, during the nine months of gestation, reduced the probability that the exposed individual had completed primary education. In the second chapter, I implement an experiment in the field to understand the effect of the exposure to role models on the reduction of the gender gap in careers that are male dominated such as Science, Technology, Engineering, and Mathematics (STEM). The gender gap in STEM fields is a major cause of concern for policymakers around the world since it not only contributes to talent misallocation but also critically deepens gender-based socioeconomic inequalities. I find that a brief exposure to role models of about 20 minutes increases preferences for engineering majors of high talented female high school students, and I attribute this to inspiration rather than information mechanisms. The evidence suggests that, inspired by role models, high math ability girls had increased self-confidence for succeeding in engineering majors. Finally, in the third chapter I investigate the misallocation of students to academic programs and more specifically the effect of one university policy related to academic probation on attrition rates and subsequent academic performance. Academic probation is a warning received by students failing to make substantial academic progress required for graduation. By receiving academic probation, students get additional information of their capabilities to successfully complete a degree. The analysis suggests that academic probation is associated with higher drop-out rates from programs and a deterioration in subsequent academic performance aiding to the retention of only qualified students in selected fields of study.

In loquat, apex of a current shoot changes from vegetative to reproductive stage during summer, i.e. under high temperature conditions. Indeed, just before floral bud differentiation, a decline in the growth rate due to high temperature takes place. The aim of this work is to study the role of this 'summer rest period' on the apex transition from vegetative to reproductive stage. For this purpose 1) sprouting of secondary shoots was promoted at different times, removing the main shoot, before, during and after floral bud differentiation occurred and 2) groups of trees were shifted to a greenhouse under average maximum temperature not exceeding 25 ° C during different periods from June to October. Floral bud differentiation was evaluated. LEAFY (LFY), APETALA (AP1), TERMINAL FLOWERING 1 (TFL1) and FLOWERING LOCUS T (FT1) expression and hormonal content in abscisic acid (ABA), gibberellins (GAs), indoleacetic acid (IAA) and cytokinins (CKs) were analyzed in bud collected during the summer. Results suggest that the date of shoot apex removal determining floral bud differentiation of new shoots, so that the percentage of the new reproductive shoots reduced with the delaying of apex removal. On the other hand, maximum average temperature not exceeding 25 ° C prevented floral bud differentiation. Buds of the trees under indoors conditons displayed lower expression of identity floral genes EjLFY and EjAP1 than buds of trees grown in field. On the contrary, the floral repressor EjTFL1 and EjFT1 gene expressed higher in buds of the trees grown indoors. Time-course of ABA decreased in buds of trees grown in field during studied period while in buds of trees under greenhouse conditions displayed a growing trend. Time-course of GAs, IAA and CKs concentrations did not show remarkable differences between buds of trees growing under field and indoors conditions. Accordingly, 1) secondary shoots emerged from mid- August are unfitness to flower and 2) maximum average tempertature 25±1 °C during the summer prevents floral bud differentiation, enhances ABA biosynthesis, reduces EjLFY and EjAP1 expression and enhance EjTFL1 expression in the apex. / El níspero japonés diferencia sus yemas durante el verano, después de un periodo de ralentización del crecimiento vegetativo ligado a las altas temperaturas que se conoce como reposo estival. El objetivo de esta tesis fue estudiar la influencia de la parada estival en la diferenciación floral de esta especie. Para ello se diseñó un experimento en el que se forzó la brotación de brotes anticipados eliminado el ápice principal en diferentes fechas entre julio y septiembre, antes, durante y después de la parada estival. Paralelamente se diseñó otro experimento en el que se cambiaron las condiciones climáticas a grupos de árboles manteniéndolos en un invernadero a una temperatura máxima media de 25 °C durante diferentes periodos de diversa duración. Se evaluó la diferenciación floral y se analizó la expresión de los genes relacionados con la floración LEAFY (LFY), APETALA (AP1), TERMINAL FLOWERING 1 (TFL1) and FLOWERING LOCUS T (FT1) y el contenido hormonal en ácido abscisico (ABA), giberelinas (GAs), ácido indolácetico (AIA) y citoquininas (CKs) en yemas terminales muestreadas a lo largo del verano. Los resultados indican que la fecha de brotación modifica la diferenciación floral de los brotes anticipados siendo el porcentaje de brotes reproductivos inversamente proporcional a la fecha de eliminación del meristemo. Del mismo modo unas condiciones de temperatura máxima no superior a 25 °C impidieron la diferenciación floral. Las yemas de los árboles que estuvieron bajo dichas condiciones mantuvieron unos niveles de expresión de los genes de identidad floral, EjLFY y EjAP1, mucho menor que la de los árboles en condiciones de campo. Por el contrario, la expresión del represor EjTFL1 y del gen EjFT1 fue mayor en los árboles en invernadero. Por otro lado, el contenido endógeno de ABA descendió en los árboles situados en el campo durante el periodo de estudio mientras que en los árboles situados en el invernadero tuvo una evolución ascendente. Las concentraciones de GAs, AIA y CKs no mostraron prácticamente diferencias entre los ápices de los árboles mantenidos en campo y en invernadero. De acuerdo con ello, 1) los brotes anticipados surgidos a partir de mitad de agosto son incapaces de florecer y 2) la ausencia de altas temperaturas del verano promueve la acumulación de ABA, aumenta la expresión del gen represor (EjTFL1) y reduce la expresión de los genes de identidad floral (EjLFY y EjAP1) en yemas de níspero impidiendo su diferenciación floral. / El nispro japonés diferència les seus gemmes durant l'estiu, després d'un període d'alentiment del creixement vegetatiu lligat a les altes temperatures que es coneix com repòs estival. L'objectiu d'aquesta Tesi va ser estudiar la influència de la parada estival en la diferenciació floral d'aquesta espècie. Per a això es va dissenyar un experiment en què es va forçar la aparició dels brots anticipats eliminat l'àpex principal en diferents dates entre juliol i setembre, abans, durant i després de l'aturada estival. Paral·lelament es va dissenyar un altre experiment en què es van canviar les condicions climàtiques a grups d'arbres mantenint-los en un hivernacle a una temperatura màxima mitjana de 25 °C durant diferents períodes de diversa durada. Es va avaluar la diferenciació floral i es va analitzar l'expressió dels gens relacionats amb la floració LEAFY (LFY), APETALA (AP1), TERMINAL FLOWERING 1 (TFL1) and FLOWERING LOCUS T (FT1) i el contingut hormonal en àcid abscísic (ABA) , gibberel·lines (GAs), àcid indolacètic (AIA) i citoquinines (CKs) en gemmes terminals mostrejades al llarg de l'estiu. Els resultats indiquen que la data de brotació modifica la diferenciació floral dels brots anticipats i el percentatge de brots reproductius es inversament proporcional a la data d'eliminació del meristema. De la mateixa manera unes condicions de temperatura màxima no superior a 25 ° C varen impedir la diferenciació floral. Les gemmes dels arbres que van estar sota aquestes condicions van mantenir uns nivells d'expressió dels gens d'identitat floral, EjLFY i EjAP1, molt menor que la dels arbres en condicions de camp. Per contra, l'expressió del repressor EjTFL1 i del gen EjFT1 va ser més gran en els arbres en hivernacle. D'altra banda, el contingut endogen d'ABA va baixar en els arbres situats al camp durant el període d'estudi mentre que en els arbres situats a l'hivernacle va tenir una evolució ascendent. Les concentracions de GAs, AIA i CKS no van mostrar pràcticament diferències entre els àpexs dels arbres mantinguts en camp i en hivernacle. D'acord amb això, 1) els brots anticipats sorgits a partir de meitat d'agost són incapaços de florir i 2) l'absència d'altes temperatures de l'estiu promou l'acumulació d'ABA, augmenta l'expressió del gen repressor (EjTFL1) i redueix l'expressió dels gens d'identitat floral (EjLFY i EjAP1) en gemmes de nispro del Japó impedint la seva diferenciació floral. / García Lorca, AL. (2017). Temperature regulating floral bud differentiation in loquat (Eriobotrya japonica Lindl.). Hormonal and genetic aspects [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/79873

Yes / Lake-dwellings in the northern Alpine region are renowned for their extraordinary organic preservation. In addition to organic remains, thousands of ceramic sherds are also recovered. This paper addresses ceramic sherds from the Late Bronze Age site Zürich-Alpenquai, and assesses over 2000 sherds for indications of erosion and abrasion in addition to quantifying sherd size and plotting the spatial distribution of these factors. Recording such wear patterns can provide indications of deposition practices in addition to environmental conditions pre- and post-deposition. In this manner the study of ceramic remains from wetland sites for abrasion can complement environmental studies addressing conditions at the time of artefact deposition, and contribute to discussions of influences for lake-settlement abandonment.

Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Since the construction of the causeway and the jetty during the early 1970’s in Saldanha Bay, various alterations to the coastline in the area of the Langebaan Lagoon mouth were observed. These alterations include the erosion of Langebaan Beach located near the town of Langebaan. An investigation was undertaken to identify the possible impact these structures had on the hydrodynamics and sediment transport of the Saldanha Bay and Langebaan Lagoon systems, focusing on the entrance to the Langebaan Lagoon. A two-dimensional numerical model was implemented for this investigation. The outdated information available for the generation of a bathymetry, which indicated the conditions prior to the erosion of Langebaan Beach, complicated the calibration process. However, calibration of the numerical model was acceptable. Due to the bathymetry not providing an indication on the current situation at the Langebaan Lagoon mouth, the results from the numerical model were approached with caution, providing an overview of the hydrodynamics present in Saldanha Bay and Langebaan Lagoon and would be able to broaden the understanding of the impact the causeway and jetty had on the hydrodynamics and sediment transport of Saldanha Bay and Langebaan Lagoon. Results provided by the sediment transport model only provide an indication on the effect tidal variations and wind forcing have on the bay and lagoon and not realistic total sediment transport rates due to the omission of wave action during the modelling process. Results from the numerical model, based on tidal oscillations and wind forcing only, have indicated that no major impact on the hydrodynamics and sediment transport were experienced due to the construction of the causeway and the jetty. During the investigation of the impact of various extreme water level and extreme wind conditions, it has been observed that a 1 in 100 year wind velocity across the longest fetch towards Langebaan Beach resulted in the greatest velocities prior to the construction of the causeway and the jetty, and after the construction of the causeway and the jetty tidal storms, or storm surge, generated the greatest velocities and thus the most sediment transport in the main channels of the mouth of the Langebaan Lagoon. From this investigation it was recommended that future studies would require an updated survey of the area, to ensure accurate modelling of the conditions as experienced during field surveys. Further recommendations on the investigation of sediment transport were the inclusion of wave action to provide realistic results. Wave action is a fundamental part of sediment transport along the coastline. / AFRIKAANSE OPSOMMING: Sedert die konstruksie van die breekwater en die kaai gedurende die vroeg 1970’s in Saldanhbaai, is verskeie veranderings aan die kuslyn in die gebied van die Langebaan strandmeer mond waargeneem. Hierdie veranderinge sluit in die erodering van Langebaan Strand, geleë naby die dorp van Langebaan. 'n Ondersoek is onderneem om die moontlike impak van die bogenoemde strukture op die hidrodinamika en sedimentvervoer van die Saldanhabaai en die Langebaan strandmeer stelsels, veral die strandmeer se kanale, met die fokus op die ingang na die Langebaan strandmeer te ondersoek. 'n Twee-dimensionele numeriese model is gebruik vir hierdie ondersoek. Die verouderde inligting van die seebodem wat beskikbaar was vir die opwekking van die numeriese model het die kalibrasieproses bemoeilik. Alhoewel hierdie proses bemoeilik is kon ‘n aanvaarbare kalibrasie bereik word. Aangesien die gemodelleerde area en die werklike area nie ooreengestem het nie is resultate van die numeriese model omsigtig benader en die resultate geskik gevind om die kennis oor die moontlike impak wat die breekwater en die kaai op die hidrodinamika en sedimentvervoer van Saldanhabaai en die Langebaan strandmeer het, te verbreed. Resultate uit die sedimentvervoer model verskaf slegs ‘n aanduiding van die sedimentvervoer wat deur gety veranderings en wind gegenereer word. Werklike sediment vervoer sal die effect van golfaksie ook in ag moet neem, wat in hierdie studie uitgesluit is. Golfaksie is van kardinale belang by sediment vervoer langs ‘n kuslyn. Resultate van die numeriese model, gebaseer op gety en wind alleen, het aangedui dat geen groot impak op die hidrodinamika en sedimentvervoer as gevolg van die konstruksie van die breekwater en die kaai in Saldanhabaai ervaar word nie. Gedurende die ondersoek van die impak van verskeie ekstreme watervlak en uiterste windtoestande, is dit opgemerk dat 'n 1 in 100 jaar windsnelheid oor die langste stryklengte na Langebaan Strand gelei het tot die grootste vloei snelhede in die hoofkanale voor die konstruksie van die breekwater en die kaai. Na die konstruksie van die breekwater en die kaai is gevind dat gety storms die grootste snelhede en dus ook die meeste sedimentvervoer gegenereer het by Langebaan Strand. Uit hierdie ondersoek is dit aanbeveel dat toekomstige studies opgedateerde opmetings van die gebied moet uitvoer wat akkurate modellering, gebaseer op die toestande soos in die veld, sal verseker. Verdere aanbevelings oor die ondersoek van sediment vervoer is die modellering van .golfaksie wat van kardinale belang is in sediment vervoer langs ‘n kuslyn en dus meer realistiese resultate sal lewer.

Everglades National Park is a hydro-ecologically significant wetland experiencing salinity ingress over the years. This motivated our study to map water salinity using a spatially weighted optimization model (SWOM); and soil salinity using land cover classes and EC thresholds. SWOM was calibrated and validated at 3-km grids with actual salinity for 1998–2001, and yielded acceptable R2 (0.89-0.92) and RMSE (1.73-1.92 ppt). Afterwards, seasonal water salinity mapping for 1996–97, 2004–05, and 2016 was carried out. For soil salinity mapping, supervised land cover classification was firstly carried out for 1996, 2000, 2006, 2010 and 2015; with the first four providing average accuracies of 82%-94% against existing NLCD classifications. The land cover classes and EC thresholds helped mapping four soil salinity classes namely, the non saline (EC = 0~2 dS/m), low saline (EC = 2~4 dS/m), moderate saline (EC = 4~8 dS/m) and high saline (EC >8 dS/m) areas. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

Thesis (MPhil (Sustainable Development Planning and Management))--University of Stellenbosch, 2007. / This is a technical and financial proposal for a large-scale and complex sustainable development project in Zambia. The sustainable development project is the Copperbelt Environment Project (CEP)1. This proposal aims at developing strategies for addressing sustainability problems of CEP. One objective of the proposed strategies is to raise additional funds to support its activities beyond CEP’s initial project-life. The other is to enhance public participation in CEP, especially of political and traditional leaders. CEP is a project of the Government of the Republic of Zambia (GRZ) created in 2002 to mitigate historical environmental and social liabilities caused by mining after the privatisation of stateowned mines. Furthermore, CEP is charged with the responsibility to improve compliance of ongoing mining operations through enhanced environmental and social regulation. CEP is faced with three key sustainability problems. The first problem relates to the cessation of CEP activities after the end of its conceptual project life span in 2008. If CEP activities cease without an exit strategy to take care of on-going CEP activities, serious environmental and socioeconomic problems are likely to arise in mining areas. The second sustainability problem relates to the financial deficit of CEP. Less than US $60 million of the US $200 million required has been sourced for CEP activities implying a deficit of about US $150 million. Unless the financial deficit is secured, it is unlikely that most historical environmental liabilities will be addressed. It is also unlikely that environmental and social regulation targets of CEP will be attained by the end of its initial life span. The third sustainability problem relates to inadequate public participation in CEP activities. Although public participation in development programmes is a policy and legal requirement in Zambia, it is however very low in CEP. Traditional and political leaders are not using their offices to advance CEP agenda. A hybrid of participatory research/action research, evaluation research, empowerment evaluation and literature reviews research methodologies is proposed to be used to develop the strategies that will address the above problems. In addition, multiple methods of data collection are proposed to be used, including structured and semi-structured individual and group interviews, questionnaires, documentary sources and analysis, plenary and focus group discussions, personal experience, commissioned expert inputs, websites and participation records. The long-term target of the proposed project is to generate in excess of US $900 million for CEP activities by 2025. The proposed project will also utilise the Community-Based Environmental Protection (CBEP) approach and draw on the South African experience on public participation to build the capacity of target groups to take stewardship of environmental problems in their areas. A detailed implementation plan will be developed to serve as the framework for operationalising the proposed strategies. Existing CEP monitoring and evaluation mechanisms will be used to track the implementation plan. A six-man team headed by a team leader is proposed to execute this project proposal. An activitybased budget including a logical framework, timescales for deliverables, coverage areas, target groups, action planning, project goals, stakeholder analysis, time plans for staff and activity schedules are proposed. Depending on the speed and efficiency with which the project proposal and its strategies are implemented, a sustainable solution to poor environmental management in mining areas of Zambia is possible.

This exploratory case study considers the Czech Republic from 1993 thru 2002 by examining two links: first, between transition and the environment.; second, between the environment and human rights. The study examines data from the Czech Ministry of Environment, the European Union, the World Bank, and Freedom House. The purpose of this study is to better understand the Czech Republic and to generate hypotheses that might be used in future cross-national studies. Chapter III provides the underlying theory linking the environment and human rights. Chapters IV, V, and VI discuss the data and the two links and suggest hypotheses for future research. Chapter VII draws conclusions about states in transition, the environment, and human rights and encourages future integrative research.