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Prior to European settlement, black bear (Ursus americanus) were far less abundant in the state of California. Estimates from statewide harvest data indicate the California black bear population has tripled in the last 3 decades. Bears inhabit areas they formally never occurred (e.g., urban environments) and populations that were at historically low densities are now at high densities. Though harvest data are useful and widely used as an index for black bear population size and population demographics statewide, it lacks the ability to produce precise estimates of abundance and density at local scales or account for the numerous bears living in non-hunted areas. As the human population continues to expand into wildlife habitat, we are being forced to confront controversial issues about wildlife management and conservation. Habituated bears living in non-hunted, urban areas have been and continue to be a major concern for wildlife managers and the general public. My objective was to develop DNA-based capture-mark-recapture (CMR) survey techniques in wildland and urban environments in Mono County, California to acquire population size and density at local scales from 2010 to 2012. I also compared population density between the urban and wildland environment. To my knowledge, DNA-based CMR surveys for bears have only been implemented in wildland or rural environments. I made numerous modifications to the techniques used during wildland DNA-based CMR surveys to survey bears in an urban environment. I used a higher density of hair-snares than typically used in wildland studies, non-consumable lures, modified hair-snares for public safety, included the public throughout the entire process, and surveyed in the urban-wildland interface as well as the city center. These methods were efficient and accurate while maintaining human safety. I determined that there is likely a difference in population density between the urban and wildland environments. Population density was 1.6 to 2.5 times higher in the urban study area compared to the wildland study area. Considering the negative impacts urban environments can have on wildland bear populations, this is a serious management concern. The densities I found were similar to those found in other urban and wildland black bear populations. The baseline data acquired from this study can be used as part of a long-term monitoring effort. By surveying additional years, population vital rates such as apparent survival, recruitment, movement, and finite rate of population change can be estimated.

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No description available.

<p>Maritime shipping is the most important mode of transportation for international trade. About 70 to 80 percent of the value traded worldwide moves by sea [1]. An inherent problem in global shipping markets is that non-competitive pricing behavior among carriers is widely believed to raise the cost of freight [2]–[5]. It is also likely that the effects of this problem on international trade flows and welfare are magnified by restricted cabotage reservation schemes. Historically, countries have implemented such policies to prohibit foreign competition in domestic shipping markets. The effects of protection on international goods trade are reasonably well understood. The effects of protection on service trade are less straight-forward. Issues of quality become more important, but they are challenging to measure. Moreover, most of these cabotage reservation schemes ban service imports. Therefore, this makes it complicated to compare domestic and foreign services in the same market, given that service activities are place-specific. </p> <p><br></p> <p>In order to better understand the effect of non-competitive pricing behavior in global shipping markets on international trade flows and the incidence of cabotage reservation schemes in shipping markets, I develop three essays. In the first Essay I focus on quantifying the economic effects of non-competitive pricing behavior in the maritime shipping industry on (1) freight costs, (2) international trade flows, and (3) economic welfare. The research question that I answer is: what share of observed shipping freight charges is attributable to non-competitive pricing behavior in maritime shipping markets? I estimate the maritime shipping mark-ups applying the method of Atkin and Donaldson [6] to U.S. Census import data of shipments moved by sea during the period 2002-2017. I find that freight mark-ups account for approximately one-third of total freight charges in U.S. imports. Carriers’ mark-ups thus represent an equivalent ad valorem tariff of 1.4-2.6 percent. U.S. imports of differentiated products would be 4.2 to 11.6 percent higher if these mark-ups were eliminated. The cost of these mark-ups in terms of economic welfare for U.S. consumers represents an annual reduction of 0.1-0.2 percent of their real income. Carriers also charge higher maritime shipping mark-ups (per kg.) to high-value products, products with a lower elasticity of substitution, and products with higher import tariffs. Imported products from developing countries or from distant countries to the U.S. are also charged with larger tariff equivalent mark-ups.  </p> <p><br></p> <p>In the second Essay I estimate the economic burden placed on Puerto Rico by the Jones Act. Using Lloyd’s List Intelligence (LLI) data to document the supply of shipping services in the U.S. -Puerto Rico shipping market, I find that the Jones Act fleet serving Puerto Rico contains no ships designed for the purpose of moving general cargo or bulk commodities. I then evaluate how this lack of supply of shipping services is a burden on imports of goods that would normally travel by ships of those kinds, modelling Puerto Rico’s import demand in a gravity framework. This exercise indicates that Puerto Rico’s demand for final goods exhibits a greater substitution towards non-U.S. sources among products that tend a) to be shipped by sea, b) to be physically heavy, and c) not to be moved in containers. I then estimate a structural gravity model to quantify the tariff-equivalent trade costs the Jones Act imposes on U.S. shipments. This model yields that the Jones Act represents a tariff equivalent of 30.6 percent on average across products. Finally, I use these estimates to calculate the compensating variation of Jones Act removal. I find that the cost of final expenditure in Puerto Rico would be $1.4 billion (about 1.3 percent) lower per year without the Jones Act. </p> <p><br></p> <p>Finally, in the third Essay I investigate what specifically explains the estimated change in Puerto Rico’s import demand for U.S. products due to the Jones Act. I use detailed data of vessels’ ports-of-call in the Caribbean from LLI to document issues of service quality and availability in maritime shipping services between the U.S. and Puerto Rico during the period 2004-2020, calculating metrics for some quality dimensions (e.g., vessels age, shipping capacity, shipping frequency and more). I also evaluate market conditions such as the concentration level in the market of carriers and shipyard building companies in order to examine the presumed incidence in shipping freight costs. Additionally, I use Puerto Rico’s import data from the Instituto de Estadísticas de Puerto Rico (IEPR) to evaluate how much the Jones Act restrictions affect the mode choice decisions for shipping products between U.S. mainland and Puerto Rico. The research question that I try to answer is: what is the level and evolution of the quality of shipping services provided by Jones Act-compliant vessels in the U.S.-Puerto Rico shipping market? </p>

There is repeated evidence that hybridization is a major contributor to the production of adaptive diversity; however, the evolutionary fate of hybrids in natural populations remains poorly understood. In Heliconius butterflies, hybridization is common and responsible for generating a variety of warning color patterns across the genus. Predator avoidance of warning colorations appears to largely be learned, which drives strong positive frequency-dependent selection. This creates a paradox for hybrid lineages: how do novel hybrid forms manage to establish and persist under such strong selection? In this dissertation, I present a series of studies centered on the selection dynamics of Heliconius hybrid zones, to elucidate how novel adaptive traits establish in nature. Clines across hybrid zones have often been analyzed to estimate selection on ecologically important loci. Here, warning color clines were characterized and compared across multiple transects along a Heliconius hybrid zone in the Guiana Shield. Furthermore, a mark-resight experiment and communal roost observations were completed near the center of this hybrid zone to determine the survival and likelihood of establishment of native and foreign forms. These studies reveal similar survivorship of hybrid and pure color patterns, and specifically demonstrate that a rare putative hybrid form can survive and establish within a hybrid zone. Both hybrids and pure color patterns showed comparable life expectancies in the mark-resight experiment and similar patterns of presence at nocturnal roosts. These results suggest that selection on warning color pattern is relatively weak within the hybrid zone. Analyses of color pattern clines uncovered strong selection bounding the hybrid zone in bi-race areas, while weaker selection was estimated for a tri-race area. In fact, the tri-race area was three times wider than the bi-race areas. Collectively, these studies suggest that the selection dynamics across hybrid zones may play an integral role in the establishment of new adaptive traits, and offers a route by which a reputed hybrid race may have arisen. The investigations within this dissertation also provide a new view of hybrid zone dynamics, and improve our understanding of how hybridization and selection shapes the evolution of biodiversity.

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Umeå är en växande stad som ligger längs norrlandskusten. Kommunen har starka mål och ambitioner för att staden ska växa de närmaste 25 åren. Kommunen planerar att komplettera ett område vid namn Berghem med 80-100 lägenheter. Ett helt nytt kvarter ska bildas på nuvarande naturmark i sluttande terräng. Kvarteret ligger nära Umeå centrum och bara ett stenkast ifrån Berghems eget centrum. Berghem är en av de dyraste stadsdelarna i Umeå att köpa en bostad på och kötiderna är bland de längsta för hyresrätter. Vid byggnation på denna plats behöver många faktorer beaktas. Att anpassa byggnaden efter platsen och dess terräng har varit arbetets stora utmaning och fokus har lagts på förstudiearbetet med en ingående platsanalys över planområdet och dess omgivning. Förstudiearbetet och platsanalysen består bland annat av resonemang kring hur solen påverkar byggnadernas placering, hur omkringliggande byggnader påverkar exploateringsgraden och hur markens terräng inverkar på utformningen. Detta arbete har som syfte att gestalta ett förslag för det nya kvarteret. Visionen har varit att skapa ett kvarter med stark anknytning till omkringliggande natur. / Umeå is a growing city that lies along the coast of Norrland. The municipality has strong goals and ambitions for the city to grow over the next 25 years. The municipality plans to complete an area named Berghem with 80-100 apartments. A new block shall be formed on current natural land on sloping ground. The area is near Umeå city center and just a stone throw away from Berghem’s own center. Berghem is one of the most expensive neighborhoods in Umeå to buy an apartment and queues for rental apartments are among the longest. Building on this area needs a lot of factors to take into account. To adapt the buildings to the area and its terrain has been the works greatest challenge, focus has been placed on the pilot study with a detailed site analysis of the area and its surroundings. Pilot study and site analysis consists among others on reasoning about how the sun affects the placement of the buildings, how the surrounding buildings affects on the rate of exploitation and how soil terrain affecting the composition. This work aims to design concept drawings for the new area. The vision was been to create a neighborhood with strong ties to the surrounding nature.

The digital revolution has introduced several tools for structural engineers in the form of computer programs. These computer tools have partly transformed the role of structural engineers from their performing manual calculations to using different computer programs, evaluating the results, and checking codes.  Advanced computer-based calculation programs are often relied on when dimensioning structural parts. However, these are associated with certain consequences, especially when using black box software, which increases the need for an estimated model.  The purpose of this paper is to examine how the design of a concrete slab is estimated and how the results of such an estimate calculation relate to the results from computer calculations. The research method involves three main steps: gathering facts from references to learn how to design a concrete slab; developing a calculation model; and learning how to use PEPS, which is a type of black box software for performing calculations. In the analysis, PEPS is compared with manual calculations and the following conclusions are drawn based on the results: The estimate dimensioning of an edge-stiffened concrete slab can be simplified by using the equilibrium equation based on the edge beam. Results from this simplified method will differ from results produced by the computer program.  Simplified calculations are used to check the reasonableness of the PEPS results: Although PEPS indicates the cause of the bearing capacity of the concrete slab, the program fails to demonstrate how the results are calculated. / Den digitala revolutionen har fått till följd att det utvecklats en mängd olika datorverktyg som konstruktörer använder i konstruktionsarbetet. Dessa datorverktyg har förändrat konstruktörens roll från att använda handberäkningar till att använda olika dataprogram som hjälper till med utvärdering av resultat och kontroll av koder.  Vid dimensionering av bärverksdelar är det vanligt förekommande att i hög grad förlita sig på avancerade datorbaserade beräkningsprogram. Det finns dock konsekvenser med det, särskilt vid användning av blackbox-mjukvaror, vilket gör att behovet av överslagsberäkning ökar. För att undvika inkorrekt konstruktionsdesign behöver konstruktörer därmed ett sätt att kunna kontrollera rimligheten av de resultat som framkommer med hjälp av dataprogram. Syftet med detta arbete är att undersöka hur konstruktionen platta på mark kan överslagdimensioneras, samt undersöka hur resultaten av sådan överslagsdimensionering förhåller sig till resultat från datorberäkningar med etablerade mjukvaror. Metoden innehåller tre huvudmoment: 1) genomförandet av en litteraturstudie för att lära sig handberäkna grundplattor, 2) framtagningen av en beräkningsmodell för överslagsberäkning samt 3) lära sig använda PEPS som är ett beräkningsprogram som kan användas vid dimensionering av betongplatta. Programmet verkar vara en blackbox-mjukvara. I resultat- och analysdelen jämförs PEPS med handberäkningar och följande slutsatser dras utifrån resultaten: En överslagsdimensionering av kantförstyvad platta på mark kan utföras med hjälp av jämviktsekvation baserad på kantbalken. Resultaten från denna förenklade överlagsmetod skiljer sig från resultaten i själva PEPS programmet. Överslagsberäkningar bör användas för att kontrollera rimligheten för PEPS resultaten. PEPS visar orsaken till bärförmågan i grundplattor, däremot visar programmet inte hur resultaten räknas fram.  Ökningen av bärförmågan hos platta på mark kan ske på olika sätt beroende på lasttyp (linje- och punktlast) samt vilken placering denna last har. Genom att ha en bättre förståelse för konstruktionens verkningssätt är det möjligt att designa platta på mark på ett mer materialeffektivt sätt.

Land contaminated with arsenic is a major problem as arsenic is toxic and poses a major health risk to both humans and animals. There are several remediation methods, both in-situ and ex-situ, to prevent and deal with pollution problems in different ways. In Hjältevad, Eksjö municipality, a leak occurred in an impregnation tank in 1968, in a facility belonging to atelephone company. As a result, the groundwater was contaminated with chromium, copper andarsenic and despite several major remediation measures, arsenic concentrations are still highand new measures are required, of which this study is a part.Previous laboratory tests with soil samples from Hjätevad, both batch and then column tests,showed that zero-valent iron particles (ZVI) in nano and micro-scale proved to be most effectiveunder given conditions to immobilize arsenic. In the present study results from a pilot scaleexperiment with micro-scale ZVI (mZVI) are presented. Before the pilot scale experiment,dynamic groundwater sampling was carried out in Hjältevad, to characterize the aquifer. Also,initial distribution tests with mZVI were conducted. Trial injections were carried out with a slurryof water, mZVI and guar. The latter was added to increased viscosity. The distribution of mZVIwas followed up with measurements of e.g., conductivity and imaging with OPI-VIS. The spreadof mZVI ranged between 0.5–1.5 meters.In the pilot scale experiment, five injection points were used 2 meters apart from each other andsix new groundwater wells were installed after the injection to monitor the effect of mZVI ongroundwater chemistry. Injections were made at 11 different depths in 0.5-meter intervals. Forfour months, measurements of different groundwater parameters were conducted. Smallreductions in arsenic levels were found in two groundwater wells downstream from the injectionpoints, but no reduction in the remaining wells.One reason for the small effect on arsenic concentration could be slow kinetics of the reactionbetween mZVI and water, due to low groundwater temperatures (7–8 °C). Another reason couldbe that the mZVI was not dispersed well enough in the soil due to either the aggregation ofmZVI particles or the heterogeneity of the soil. / Arsenikförorenad mark är ett stort problem då arsenik är toxisk och utgör en stor hälsorisk förbåde människor och djur och bör därför saneras. Det finns flertalet saneringsmetoder både in-situoch ex-situ för att på olika sätt både förebygga och ta itu med en föroreningsproblematik. IHjältevad, Eksjö kommun, skedde ett läckage i en impregneringstank år 1968, i dåvarandeTeleverkets anläggning. Detta förorenade grundvattnet med krom, koppar och arsenik och trotsflera stora saneringsåtgärder var arsenikkoncentrationerna höga och nya åtgärder undersöktes,vilket denna studie är en del av.I ett tidigare arbete genomfördes laborationsförsök med jordprover från Hjätevad, först skak- ochsedan kolonnförsök med lovande resultat där ickesulfiderat mikrojärn visade sig mest verksamtunder givna förutsättningar. I detta examensarbete undersöktes möjligheten att fastlägga arsenik igrundvattenzonen genom att injektera nollvärt järn i mikroskala (mZVI) i ett pilotskaleförsök.Innan pilotskaleförsöket genomfördes även på plats i Hjältevad både dynamiskgrundvattenprovtagning för att få en djupprofil på grundvattenkemin. I ett inledandedistrubitionstest genomfördes provinjektioner av en slurry med mZVI blandad med guar för attge ökad viskositet, vars spridning följdes upp med mätningar av bl.a. konduktivitet och bildermed OPI-VIS. Spridnigen blev mellan 0,5-1,5 meter.I pilotskaleförsöket användes fem injekeringspunkter och sex nya grundvattenrör installeradesefter injekteringen för att följa upp effekten i grundvattnet. Injekteringarna gjordes på 11 olikadjup med ett intervall på 0,5 meter. Effekterna i grundvattnet följdes upp under fyra månadergenom mätningar av pH, EH, As(III), total As och Fe. Små minskningar av arsenikhalterna kundekonstateras i de två provbrunnarna på störst avstånd nedströms från injekteringarna, men ingenminskning i övriga provbrunnar. En orskak att minskningen av arsenikkoncentrationen inte blevstörre kan vara långsam kinetik i reaktionen mellan vatten och mZVI, vilken potentiellt ärtemperaturberoende. När mZVI reagerar med vatten bildas olika järn(hydr)oxider, vilka kanbinda löst arsenik. En annan är orsak kan vara att mZVI inte har spridits tillräckligt bra i markenpå grund av antingen att mZVI-partiklarna klumpat ihop sig eller heterogeniteten i marken.