Mercury (Hg) transport in streams is typically facilitated by dissolved organic matter (DOM), however, the dynamics of Hg and DOM during snowmelt in montane watersheds are poorly understood. Hg transport during snowmelt is widely recognized as a significant source of Hg to downstream lakes and reservoirs, such as Jordanelle Reservoir where fish consumption advisories are in effect due to elevated Hg concentrations in certain species of fish. For this study, total mercury (THg), methylmercury (MeHg), and DOM samples were collected at three sites in the upper Provo River, northern Utah, during the 2016 and 2017 water years. To evaluate Hg and DOM sources, samples were collected from snowpack and ephemeral streams in the watershed. In-situ fluorescent DOM (fDOM) data and other parameters were measured in the river to characterize high-frequency variation in water chemistry. Excitation-emissions matrices (EEMs) were used to determine changes in DOM characteristics during snowmelt. Hg concentrations increased in the upper Provo River from /L during baseflow to >;7 ng/L during the snowmelt period (~April-July), with filtered THg concentrations approximately ~75% of the unfiltered concentrations. In the watershed, filtered THg concentrations ranged from ~0.4 ng/L in snowpack to ~8 ng/L in ephemeral streams. Annual THg loading from the Provo River to Jordanelle Reservoir was approximately 1 kg/yr with ~90% of the flux occurring during the snowmelt period. High correlations between filtered THg and fDOM allowed for the development of a high frequency filtered THg proxy using in-situ fDOM sensors. DOM characteristic during the snowmelt period showed that Hg transport was facilitated by humic substances which was sourced from upland soils. Fractions of filtered methylmercury (MeHg) and filtered THg (filtered MeHG:filtered THg) were ~0.1 during baseflow and reduced to ~0.01 during snowmelt, implying that snowmelt runoff has little impact on the MeHg flux to Jordanelle Reservoir. The results suggest that Hg and DOM are flushed from soils during snowmelt, and that a significant majority of the Hg flux occurs the snowmelt period. Our study has implications for understanding Hg sources and transport mechanisms in other snowmelt dominated watersheds.

A combination of factors including land use change and fire suppression has resulted in the loss of pine savanna habitats across the southeastern U.S., affecting many avian species dependent on these habitats. However, due to the ephemeral nature of the habitat requirements of many pine savanna species (e.g., habitat is only present for a couple of years after a fire), targeted management of such habitats can be challenging. Moreover, the growing numbers of imperiled pine savanna species can make prioritizing management difficult. One potential tool to better inform management of pine savanna species is satellite imagery. Sentinel-2 satellite imagery data provides an instantaneous snapshot of habitat quality at a high resolution and across a large geographic area, which may make it more efficient than traditional, ground-based vegetation surveying. Thus, the objectives of my research were to 1) evaluate the use of remote sensing technology to predict habitat occupancy for pine savanna species, and 2) use satellite imagery-based models to inform multispecies management in a pine savanna habitat. To meet my objectives, I conducted point count surveys and built predictive models for three pine savanna bird species: Bachman's Sparrow (BACS; Peuacea aestivalis), Northern Bobwhite (NOBO; Colinus virginianus), and Red-Cockaded Woodpecker (RCW; Dryobates borealis) across Georgia. I assessed the performance of satellite imagery in predicting habitat occupancy of these pine savanna species and its potential for multispecies management. I found that models created using satellite imagery habitat metric data performed well at predicting the occupancy of all three species as measured by the Area Under the Receiver Operating Characteristic Curve: BACS=0.84, NOBO=0.87, RCW=0.76 (with values between 0.7-1 defined as acceptable or good predictive capacity). For BACS and NOBO, I was able to compare these satellite imagery models to field-based models, and satellite models performed better than those using traditional vegetation survey data (BACS=0.80, NOBO=0.79). Moreover, I found that satellite imagery data provided useful insights into the potential for multispecies management within the pine savanna habitats of Georgia. Finally, I found differences in the habitat selected by BACS, NOBO, and RCW, and that BACS may exhibit spatial variations in habitat use. The results of this study have significant implications for the conservation of pine savanna species, demonstrating that satellite imagery can allow users to build reliable occupancy models and inform multispecies management without intensive vegetation surveying. / Master of Science / Land-use changes have resulted in the disruption of natural disturbances such as fires, resulting in the loss of pine savanna habitats throughout the southeastern U.S. Although many of the species that occupy these habitats are experiencing rapid population declines, habitat for pine savanna species can be challenging to manage. Without reoccurring fire, pine savanna habitat can become unsuitable for obligate species within short periods of time, forcing these species to disperse to newly disturbed habitats. The transient nature of the preferred habitat of pine savanna species makes targeting management for these species difficult, as it can be challenging to locate exactly where occupied habitats exist. Furthermore, as the number of pine savanna species that are declining is large, prioritizing management of these species can be difficult especially given limited conservation funding. One potential tool to better inform the management of pine savanna species is satellite imagery. Satellite imagery can capture habitat information across broad areas, at fine resolutions, and at frequent intervals, potentially making satellite imagery more efficient than conducting field vegetation surveys on the ground for gaining information on habitat suitability. Thus, the objectives of my research were to 1) determine if satellite imagery can effectively predict the habitats occupied by pine savanna species (habitat occupancy), and 2) use satellite imagery-based models to inform the simultaneous management of multiple species (multispecies management) in a pine savanna habitat. To meet these objectives, I conducted surveys and built predictive models for three pine savanna bird species: Bachman's sparrow (BACS; Peuacea aestivalis), Northern Bobwhite (NOBO; Colinus virginianus), and Red-Cockaded Woodpecker (RCW; Dryobates borealis) in Georgia. I found models informed by satellite imagery performed well at predicting habitats occupied for all three species. Furthermore, models developed using satellite imagery performed better at predicting the habitats occupied by pine savanna species than models developed using on the ground vegetation surveys. I also found that satellite imagery data provided useful insights into strategies to manage pine savanna species simultaneously. I found evidence that BACS, NOBO, and RCW may have contrasting habitat needs and that BACS may use habitat differently between sites in Georgia. The results of this study demonstrate that satellite imagery can be used to predict the habitats occupied by pine savanna species and inform multispecies management without surveying vegetation on the ground, which is a more efficient use of time and funding.

The movement and distribution of elephants can be influenced by environmental factors over time (Foley, 2002). Examining how features in the landscape such as vegetation productivity, water sources and anthropogenic activities drive the movement of elephants can help in understanding patterns of movement. It can also help to inform the establishment and alignment of protected areas, wildlife corridors and identification of tourism hotspots as well as policy interventions to manage Human-Elephant Conflict (HEC). The Okavango Panhandle in Botswana is a HEC hotspot and the focus of My study. A number of strategies to address HEC are underway in the area, however one longer term strategy that has been proposed in this area involves provision of artificial water sources to influence elephant movements and keep animals away from fields during the cropping season. However, an improved understanding of how elephants utilize their habitats in relation to natural ephemeral surface water and other factors that influence their movements from dryland habitats to the Okavango Delta resources is needed to inform such management decisions. My study seeks to establish the role of ephemeral surface water on elephant distribution in the eastern Okavango Panhandle, Botswana as well as assess the movement distribution of elephants in relation to the seasonality, proximity and spatial extent of water presence represented by ephemeral surface water. Time series analysis of water extent on ephemeral surface water of the eastern Okavango panhandle will be developed and overlaid with elephant movement datasets. Elephant collar data from 15 elephants (5 males and 10 females) in the eastern Okavango Panhandle, Botswana have been analysed and Home Range (HR) sizes estimated using Kernel Density Estimation (KDE). The relative importance/probability of environmental variables in determining elephants' movement based on the Utilization Distribution (UD) were computed using Generalized Linear Mixed Models (GLMMs). I utilized a remote sensing spectral index, namely the Automated Water Extraction Index (AWEI) to delineate ephemeral surface water in dryland (excluding permanent waters) of the study area. The results reveal that during the wet season, elephants were evenly spread out all over the study area until the early dry season (April-June) when the ephemeral waterholes dried up. Elephants moved southwards towards the permanent waters of the Okavango River, where there are many human settlements and farms. Male HR sizes were found to be bigger than those of female elephants. Wet season (early and late) home range sizes were also bigger when compared to dry season (early and late) HR size. Mean daily distances were computed to investigate the effect of season on elephant daily distances and the distances ranged between 5km and 6.8km in the late wet and in the early wet and late dry season respectively. The Resource Selection Function (RSF) analysis shows that water adjacent sites are preferred over distant ones and both sexes prefer areas with high NDVI, with this preference being more pronounced in males. The seasonal variation of water use is notable in that it affirms the importance of proximity to water for elephants and has implications for their management and HEC. For example, I found that ephemeral surface water has a significant role in influencing elephant spatial use in the area, particularly during the early and late wet season. As ephemeral pans dried and NDVI (vegetation greenness) decreased, elephants started to move closer to the Okavango Delta and consequently human settlements and fields. However, further investigations into the timing of movements away from ephemeral waterholes and the influence of other environmental factors on elephant movements in the area would be needed before any recommendations can be made regarding artificial water provision in this area.

No description available.

Abstract  Background: Online marketing has transformed how businesses engage with consumers, largely through the rise of social media and ephemeral content within. These platforms facilitate direct communication and engagement by providing short-lasting content that captures the consumers’ attention in a quick manner, tapping into consumers’ fear of missing out. Despite increased use of said marketing tactics and content, ephemeral marketing impact on consumer perception and engagement is largely under-researched, specifically with an industry emphasis, in this case the fitness apparel industry. Purpose: The main goal of the study is to find out how Gen Z consumers of the fitness apparel industry perceive and engage with ephemeral marketing, and the variables which have an effect on these. Method: A qualitative method with a deductive approach through two focus groups consisting of Gen Z consumers from Jönköping University. Primary data was analysed through a deductive thematic analysis using a conceptual framework derived from the Elaboration Likelihood Model. Conclusion: A thorough interpretation and analysis of the empirical findings provided a proper understanding of consumers perception and engagement with ephemeral marketing, emphasising the importance of different elements in the ephemeral content. Furthermore, there were new findings regarding the influential factor FOMO, which demonstrated the potential to be an element alongside WOM and eWOM, playing a role in both central and peripheral routes. Thus, a final reconceptualization of the conceptual model is presented.

This thesis analyzes Application Layer security protocols for certificate enrollment and management. EDHOC, Ephemeral Diffie-HellmanOver COSE, is a recently developed key exchange protocol whichis designed to provide authentication and key-exchange functionality with compact message sizes and minimum round-trip-time. The workof this thesis extends the EDHOC protocol with a certificate enrollment functionality, targeting IoT constrained devices and it has been implemented for analysis and evaluation purposes. The main scope of this document is to study the security, performance and scalability (in descendingorder of importance) of enrollment over EDHOC compared to other certificate enrollment protocols. / Detta examensarbete analyserar säkerhetsprotokoll av typen ApplicationLayer för certifikatregistrering och hantering. EDHOC, Ephemeral Diffie-Hellman Over COSE, har implementerats, analyserats och utvärderats. EDHOC är ett nyligen utvecklat Application Layer-protokoll som är utformat för att tillhandahålla autentiserings- och nyckelfunktionsfunktioner med kompakta meddelandestorlekar och minimala rundturstider, inriktat på IoT-begränsade enheter. Huvudområdet för examensarbetet är att studera säkerhet, prestanda och skalbarhet (i fallande ordning av betydelse) hos EDHOC jämfört med andra föreslagna Application Layer-säkerhetsprotokoll som utför certifikatsskrivning.

Boreal landscapes cover a large part of both Sweden and the northern hemisphere. The hydrology of the boreal landscape is complex, with several factors that can affect it in a physical and/or chemical manner. In the Krycklan catchment area, 68km2, located in northern Sweden close to Umeå, data has been collected at several sites giving both stream flow and water chemistry information. In 2017 samples from 34 sites were collected and analysed from ephemeral streams within the Krycklan catchment area for the first time ever.  In this project, data that has been collected from the ephemeral streams will be correlated with data from the perennial streams in the catchment area. There are several hypotheses at the start of this project that suggests that within the ephemeral streams the DOC will be lower, and the CO2 will be the same. The aim of the project is to find out if there are any patterns that differentiates the ephemeral streams from the perennial streams or if there are no patterns at all. Since there is not so much data available for the ephemeral streams, the conclusions that might be reached in this project won’t be completely reliable. However, if interesting patterns are found the project could expand in the future and more samples can be taken to use for more precise analyses. / Boreala landskap täcker en stor del av både Sverige och norra halvklotet. Det boreala landskapets hydrologi är komplext, med flera faktorer som kan påverka det på ett fysiskt och/eller kemiskt vis. I Krycklans avrinningsområde, 68 km2, beläget i norra Sverige nära Umeå, har data samlats in på flera platser som erbjuder data för både flöde och vattenkemi. År 2017 samlades prover från 34 efemära strömmar och analyserades för första gången inom Krycklans avrinningsområde. I det här projektet kommer data som samlats från de efemära strömmarna att korreleras med data från de konstanta vattendragen i avrinningsområdet. Det finns ett par hypoteser i början av detta projekt som tyder på att inom de efemära strömmarna kan DOC halter vara lägre och CO2 halter kommer att vara densamma. Syftet med projektet är att ta reda på om det finns några anmärkningsvärda skillnader mellan de efemära strömmarna och de konstanta vattendragen. Eftersom det inte finns så mycket data tillgänglig för de efemära strömmarna kommer de slutsatser som kan uppnås i detta projekt inte att vara helt tillförlitliga. Om intressanta mönster finns däremot kan projektet expandera i framtiden och fler prover kan tas för att användas för mer exakta analyser.

Made available in DSpace on 2014-07-29T16:28:02Z (GMT). No. of bitstreams: 1 Dissertacao Raul Collantes.pdf: 2251061 bytes, checksum: 6d5dd7bb727958c6f9fe152417c81e66 (MD5) Previous issue date: 2010-04-06 / The present work proposes a theoretical reflection around the photographic images produced by the author between the years 2001 and 2006 during the passing of certain visual effects of a transitory nature that appear in the city. The analysis of images is proceeded by a historical review on urban morphology and iconography; the image of the city; and on a selection of American and European photographers that included the city within their preferred subject matter. In the second part of the article the intention is to be explicit on some of the positions that underlie the fundamental concepts of the author's work, starting with the explanation of the language around the ephemeral and then developing aspects relating to the technical image, an unbreakable element of the photograph. Finally, the study focuses on an interpretative and descriptive analysis, looking at historical, technical, aesthetic and conceptual elements of the most representative images that form part of the author's three thematic exhibitions. At this stage it explores: the embedding in photographic aesthetics of facets of simple and routine urban daily life; the potential of reflection in water on the ground; as well as the dominance of shadows in the contemporary vision of creative photography. / O presente trabalho propõe uma reflexão teórica em torno das imagens fotográficas de produção do autor, feitas entre os anos 2001 e 2006, no decorrer de específicos efeitos visuais de caráter transitório que surgem na cidade. Previamente à análise das imagens se inclui uma revisão histórica sobre a morfologia e iconografia urbana, sobre a imagem da cidade e a obra de uma seleção de fotógrafos americanos e europeus que incluíram a cidade dentro das suas temáticas preferidas. Na segunda parte se busca deixar explícitos alguns posicionamentos sobre temáticas que fundamentam conceitualmente a produção do autor, começando pela explicação sobre a linguagem em torno do efêmero e desenvolvendo aspectos relacionados à imagem técnica como elemento indissolúvel da fotografia. Finalmente o estudo se debruça sobre a análise descritiva e interpretativa, na base de elementos históricos, técnicos, estéticos e conceituais, de imagens representativas que fizeram parte de três exposições temáticas do autor. Nessa fase se explora: a incorporação na estética fotográfica de motivos simples, anódinos e comuns do cotidiano urbano; a potencialidade do reflexo nas poças de água do chão; assim como o domínio das sombras na visão contemporânea de fotografia criadora.

This study aims to establish current levels of narcissistic tendencies among the major Snapchat demographic, 18 to 34-year-olds in the United States. Like the Raskin and Terry 40-item Narcissistic Personality Inventory, commonly referred to as NPI-40, the present survey utilized a smaller variant with 16 items, known as NPI-16, for participants. This study may provide indications for further research and advertising techniques using social media, specifically Snapchat.

Comprendre comment les pratiques agricoles affectent l’assemblage des communautés de plantes adventices dans les parcelles de grandes cultures annuelles est un enjeu majeur en agro-écologie. Les plantes adventices sont supposées partager certaines caractéristiques écologiques qui leur permettent de se maintenir dans les parcelles cultivées malgré les contraintes environnementales exercées par les pratiques agricoles. De plus, l'assemblage des communautés adventices est supposé dépendre d'interactions entre des processus écologiques opérant pendant une année de culture (par exemple : filtre abiotique) et à l'échelle de la succession des années de cultures (par exemple : dispersion temporelle). Les travaux présentés dans cette thèse ont pour but de tester ces deux hypothèses.Premièrement, nous avons comparé les pools d’espèces adventices aux plantes non adventices retrouvés dans les milieux ouverts et non cultivés sur la base de traits fonctionnels pour identifier les caractéristiques écologiques propres aux adventices. Les résultats montrent que les plantes adventices représentent un sous-échantillon des plantes retrouvées plus largement dans les milieux ouverts principalement filtré par les perturbations type travail du sol. Deuxièmement, j'ai proposé des dynamiques de type méta-communautés temporelles pour prédire les patrons de diversité attendus en fonction de l'influence de la dispersion temporelle et des variations temporelles des conditions environnementales sur l'assemblage des communautés. J'ai ensuite testé ces prédictions et quantifié la contribution relative des processus écologiques contemporains et passés sur l’assemblage d’une communauté. Pour ce faire, j'ai utilisé le jeu de données Biovigilance flore qui est un suivi sur une décennie des communautés de plantes adventices observées dans 1400 parcelles cultivées. Mes résultats montrent que l’assemblage d’une communauté de plantes adventices dépend d'interactions entre la dispersion temporelle et les conditions environnementales contemporaines de ladite communauté. De plus, mes travaux suggèrent que les risques d’extinctions des espèces adventices augmentent pour des niveaux de variations temporelles des conditions environnementales forts. Analyser directement la composition des banques de graines adventices me permettrait de valider cette hypothèse. Finalement, mes résultats confirment que l’assemblage des communautés adventices est largement imprévisible. Je propose donc un scénario basé sur la théorie des dynamiques de patches et du priority effect pour expliquer ce phénomène.En conclusion, les travaux présentés dans ce manuscrit nous permettent de mieux comprendre comment les pratiques agricoles interagissent avec des processus écologiques à différentes échelles spatiales et temporelles pour façonner les communautés de plantes adventices. / Understanding how farming practices affect weed community assembly in arable fields is a core challenge of agro-ecology. Weeds are supposed to share particular ecological characteristics that allow them to colonize arable fields despite environmental constrains exert by farming practices. In addition, interactions between ecological processes operating during a cropping season (eg: abiotic filtering) and at the scale of crop succession (eg: temporal dispersal) are supposed to drive weed community assembly in arable fields. These two hypotheses have been tested in my phD work.First, we compared a pool of weed species to a pool of non-weed herbaceous plants based on several functional traits to identify which functional traits and which strategies best characterized weeds. Our result brought evidences that weeds are a subset of non-weed herbaceous plant principally filtered out in arable fields by disturbances such as tillage. Second, I proposed different expected diversity patterns according to the influence of temporal dispersal and temporal variation of environmental conditions within temporal meta-community dynamics. Then I tested these predictions and quantified the respective contribution of contemporary and past ecological processes on weed community assembly. To do so, I used long term weed monitoring Biovigilance Flore dataset. Results showed that weed community assembly relies on complex interactions between temporal dispersal and contemporary environmental conditions. In addition, weed extinction risk seemed to increase for strong temporal variation of environmental conditions. However weed seed bank analyses are needed to confirm this hypothesis. Finally, my results confirmed that weed community assembly is largely unpredictable. I propose that patch dynamics and priority effects may explain this phenomenon.To conclude, the work presented here shade new lights on how farming practices interact with ecological processes across temporal and spatial scales to drive weed community assembly in arable fields.