Inductively coupled plasma mass spectrometry is a well-established technique for the measurement of isotope ratios. Double focussing mass analysers enable increased resolution to be applied to separate spectroscopic interferences, or the use of multi-collector detection techniques for high precision isotope ratio determinations. For the Central Science Laboratory (CSL), trace elements team, methods were developed for Zn and Fe isotope ratio measurements in acid digested faecal samples from a human nutritional study. For Zn, a novel high resolutionlmulticollector combination was employed; for Fe a single collector, high resolution method was used. In both cases, samples from the nutritional study known to contain the analytes in natural isotopic abundance were used to correct for the mass bias. Two independent methods for determining Zn and Fe isotope ratios were used to validate the measurement strategies. The team at CSL are also involved in the authentication of food products. Isotope ratio and elemental concentration data were used to determine the geographical origin of rice samples, and to distinguish between traditional and modem Basmati rice grown in India and Pakistan. NERC Isotope Geosciences Laboratory are primarily concerned with the achievable accuracy and precision of an isotope ratio measurement. Use of a mass bias correction expression appropriate to the ICP-MS instrument is essential for high quality isotope ratio measurements. Cd and Sn were used to study the variation of the mass bias in a double focussing ICP-MS system with time, absolute mass and mass difference. It was proposed that mass bias should be considered as a result of the change in the instrument response with mass, and not a fundamental parameter in its own right. A method for determination of the best mass bias correction model for an individual instrument, through examination of the instrument response function was developed.

Understanding the sources of the dust that forms the extensive loess deposits on the Chinese Loess Plateau is crucial for reconstructing atmospheric circulation patterns and dust pathways. Dust sources are however highly debated, mainly due to the low resolution of many records and the often ambiguous nature of geochemical proxies. The widely used concept of elemental ratios as provenance indicators is based on the idea that the relative abundance of immobile elements remains unaffected by chemical weathering, thereby preserving source signals. High-resolution spatial and temporal records of loess composition were determined for two study sites and three lithostratigraphic units using bulk X-ray fluorescence (XRF) analysis, and independently dated using Optically Stimulated (OSL) and post-IR Infrared Stimulated (pIR-IRSL) Luminescence dating. Four elemental ratios were chosen based on element properties of mobility and grain size, linear correlation strength and the existence of lithostratigraphic trends: Ti/Al, Si/Al, K/Al and Fe/Ti. Potential source signals were detected at both sites, at glacial-interglacial transitions as well as within lithostratigraphic units. Source changes detected within lithostratigraphic units show millennial-scale variability, indicating that abrupt shifts in dust provenance are possible. This implies that millennial-scale variability of the East Asian Monsoon may be related to changes in atmospheric dust content.

Correlated ordinal data typically arise from multiple measurements on a collection of subjects. Motivated by an application in credit risk, where multiple credit rating agencies assess the creditworthiness of a firm on an ordinal scale, we consider multivariate ordinal models with a latent variable specification and correlated error terms. Two different link functions are employed, by assuming a multivariate normal and a multivariate logistic distribution for the latent variables underlying the ordinal outcomes. Composite likelihood methods, more specifically the pairwise and tripletwise likelihood approach, are applied for estimating the model parameters. We investigate how sensitive the pairwise likelihood estimates are to the number of subjects and to the presence of observations missing completely at random, and find that these estimates are robust for both link functions and reasonable sample size. The empirical application consists of an analysis of corporate credit ratings from the big three credit rating agencies (Standard & Poor's, Moody's and Fitch). Firm-level and stock price data for publicly traded US companies as well as an incomplete panel of issuer credit ratings are collected and analyzed to illustrate the proposed framework. / Series: Research Report Series / Department of Statistics and Mathematics

Master of Science / Department of Geology / Matthew Kirk / Groundwater from the High Plains aquifer is vital for food production and a growing human population in the Great Plains region of the United States. Understanding how groundwater quality is changing in response to anthropogenic and natural processes is critical to effectively managing this resource. Our study considers variation in groundwater geochemistry in the Great Bend Prairie aquifer, a portion of the High Plains aquifer in southcentral Kansas. We collected samples during summer 2016 from 24 monitoring wells and compared our results to data collected previously from the same wells from 1979 to 1987. We sampled 13 wells screened in the upper portion of the aquifer (avg. depth 72 ft), 10 wells screened near the aquifer base (avg. depth 141 ft), and one well screened in underlying bedrock. Compared to initial samples, samples we collected tended to have higher total dissolved solids (TDS) and nitrate content, particularly those we collected from the upper aquifer. Compared to initial samples, TDS was 78 mg/L higher in samples we collected from the upper aquifer and 373 mg/L lower in samples we collected from the aquifer base on average. Nitrate exceeded the U.S. standard for public supplies of drinking water (10 mg/L as N) in seven of the samples we collected, compared to only two samples collected previously. Compared to previous samples, nitrate concentrations were 9.5 and 3.9 mg/L as N higher on average in samples collected from the upper aquifer and aquifer base, respectively. Based on a mixing analysis, variation in the salinity of our samples primarily reflects the dilution of natural Permian brines by freshwater recharge throughout the area. However, salinity decreases observed in four samples reflects flushing of initial oil brine contamination over time, salinity increases in two samples may be due to evapotranspiration, and salinity increases in two samples may reflect migration of oil-brine contamination towards the site. Stable nitrogen (15N/14N) and oxygen (18O/16O) isotope ratios in our samples primarily fall within the range typical of nitrification of ammonium-based fertilizers with potential contributions from manure or sewage. In our analysis of the microbial community, we observed groups capable of denitrification, including genera within Nitrospirae, Firmicutes, and Proteobacteria. Despite their presence, our results demonstrate that water quality in the aquifer has degraded over the past 30 to 40 years due to nitrate accumulation.

Seagrass habitats are highly productive ecosystems that support marine food webs and provide essential habitat for a variety of species. Seagrass coverages are declining in abundance worldwide. For southeastern Florida in particular, one of the main causes of the decline is disturbance from dredging and removal of substrate. Seagrass beds at three locations in the vicinity of Port Everglades, Florida were assessed for their trophic contribution to the marine organisms in the area. Seagrasses, algae, invertebrates, and vertebrates from the beds were identified and analyzed for stable carbon and nitrogen isotope ratios to determine their contribution as a food source. Significant differences were found in both δ13C and δ15N between both seagrass species and among the three sites. The δ13C of Johnson’s seagrass Halophila johnsonii ranged from -16.28 to -11.27‰ while shoal grass Halodule wrightii ranged from -15.78 to -13.36‰. The δ15N for H. wrightii were more constrained than those of H. johnsonii, 4.69 to 7.08‰ versus 0.80 to 7.86‰, respectively. Neither seagrass species appeared to be a dominant food source for marine organisms at all three study sites. However, the δ13C and δ15N of both seagrass species, Halophila johnsonii and Halodule wrightii, did fall in the fractionation range of potential consumers, -28.78 to -17.11‰ and 1.96 to 12.63‰, indicating that these animals could be ingesting pieces of seagrass while grazing on epiphytes and other primary producers in the area. Epiphytes found on the seagrass blades appeared to be a greater trophic contributor to local organisms. So while the seagrass species in question may not have been major contributors to the diet of many of the local consumers, the seagrasses nontheless played a vital role as habitat for the epiphytes that did serve as a trophic resource in these communities.

The diploma thesis focuses on finding ways to increase the performance of a selected manufacturing company by the use of benchmarking. The thesis applies theoretical knowledge from literature to the practical level by using analyses. Based on these analyses there are made proposals that contribute to the increase of a business performance.

The stone crab, Menippe mercenaria, supported the third most valuable fishery in Florida in 2016. Declining catch per unit effort (CPUE) and overall negative trend in landings since 2000 have raised concerns among fisherman, researchers, and fishery managers about the resiliency of the fishery. The Florida Fish and Wildlife Research Institute estimated that the Florida stone crab fishery has been overexploited since 1997. Overexploited fisheries, such as the commercial stone crab fishery, risk induced changes in life history parameters, such as age at maturation and reproductive output. In turn, these population-level changes have the potential to reduce the spawning stock biomass and future recruitment to the fishery. The research presented in this dissertation was intended to assess the Florida stone crab fishery stock for: 1) size at sexual maturation in females, 2) size at maturation in males, 3) potential fecundity, modeled as a function of spatial and temporal variables, 4) spawning potential ratios, an index that reveals potential recruitment overfishing, by formulating a per recruit model using the reproductive indices developed in this research, and 5) evaluating the impact of management changes on the spawning stock biomass. The physiological, behavioral, morphological, and functional maturity of female stone crabs were assessed in individuals collected throughout the fished range of the population on the west Florida shelf (Cedar Key – Sawyer Key). Histology was used to determine oocyte maturity, presence of spermatophores, and presence of postovulatory follicles. Decision-tree analysis suggested that 50% of female stone crabs were mature at 43 mm carapace width, when using a combined variable of physiological and behavioral maturity. The decision tree accurately classified 98% of mature females and 85% of immature females. Morphological maturity was assessed using piecewise regression to determine where allometric changes in growth occurred between carapace width and crusher claw length. The transition point between mature and immature females occurred at a carapace width of 66.3 mm. Differences in estimates of size at sexual maturity between morphological and physiological, behavioral, and functional maturity indicate that relative growth of body parts is not a reliable estimate of sexual maturity in stone crabs. Histological analysis revealed that smaller females are contributing to the spawning population more than previously estimated. The corresponding carapace width at which female stone crab claws are vulnerable to harvest, occurs at 78 mm. The new estimates indicated that females contribute to the spawning population 1-2 times prior to vulnerability to the fishery. Continued monitoring of sexual maturity using these methods is recommended to strengthen understanding of the fishery and of interactions between stone crab populations. Two methods were used to assess sexual maturity physiologically and morphologically in male stone crabs collected throughout the range of the fishable population. Histology was used to identify the production of spermatophores in the anterior vas deferens, indicating physiological maturity, and each crab was assigned a maturity stage. Decision-tree analysis suggested that physiological maturity occurred at a carapace width of 34.8 mm, accurately classifying 98.9% of mature males accurately and 72.5% of immature males. Piecewise regression estimated that the allometric relationship between carapace width and crusher claw length changed at a carapace width of 63.1 mm. The difference between physiological and morphological estimates of size at sexual maturity indicates that, like females, changes in male allometric relationships between body parts may not be a reliable indicator of sexual maturity. Large morphometrically mature males may be more successful in mating encounters, but in times of flux in population size structure, morphologically immature, but physiologically mature, males may have more opportunities for successful mating encounters. Carapace width at which male stone crab claws are vulnerable to the fishery occurs at 88 mm, indicating that they are capable of contributing to the reproductive population multiple times prior to vulnerability to the fishery. Multiple factors influencing variability in stone crab batch fecundity were quantified across Florida fishery sites, by implementing a negative binomial model. Fecundity was strongly and positively related to carapace width, and parameter estimates indicated that batch fecundity was on average higher at Pavilion Key (southwest Florida) and Tampa Bay (central Florida), relative to Sawyer Key (south Florida) and Cedar Key (northwest Florida) sites at the northern and southern ends of the study area. Fecundity varied among 2013-2016 and was highly variable among months. In general, the lowest batch fecundity occurred in winter and spring months, while peak batch fecundity occurred in July and August, highlighting the common seasonal trend in crustacean reproductive cycles. Comparison to a 1993-1995 study of fecundity estimates in Tampa Bay, Florida indicated that there was little change in stone crab fecundity between individuals collected in 1993 and 2013. However, this temporal relationship accounts for a small portion of the fished population and may not be reflective of the changes over time across the entire fishery. Although sea surface temperature and ocean color data do not explain the variability in fecundity between sites, I hypothesize that food quality and quantity and fishing effort may play critical role in regionally variable individual reproductive output. I suggest that given the variability in reproductive output and regional fishing practices, that further work be dedicated to identifying critical spawning and recruitment areas to ensure resiliency of the stone crab population. Spawning potential ratios were used to evaluate the impact of alternative biological and management scenarios to the reproductive output in a theoretical stone crab population. The model incorporated the findings of size at maturation and fecundity established in previous chapters, as well as contemporary temperature-dependent declaw mortalities. Spawning potential ratios increased with decreasing size at sexual maturity and were sensitive to past and present estimates of size at sexual maturity, and increasing natural mortality. However, the largest contributor to changes in the fished stock appears to be mortality associated with declawing and releasing stone crabs. We assessed various management scenarios including declaw lengths, vulnerability to capture, and variable season timing and length. Increases in declaw length and size at vulnerability to capture provided moderate protection to the spawning stock. The model estimated that adaptive management regulations which considered the timing and duration of seasonal fishing, based on mean monthly temperatures below 24°C (temperature at which declaw mortality increases), had the potential to greatly reduce mortality, and provided protection to the spawning population. The model was able to examine a wide range of biological and management scenarios; however, more research should be conducted to determine the socioeconomic impact of regulation changes. The Florida stone crab fishery is an amalgamation of unique fishing practices, rich culture, and both regional and economic influence. Evolving fishing practices, conservation initiatives, and environmental conditions have the potential to transform the fishery. Therefore, fisheries managers, scientists, and stakeholders must work cooperatively to ensure the resiliency of the stone crab fishery.

Abstract The Surma basin is a part of the Bengal Basin situated in northeastern Bangladesh. The presence of eight gas fields and one oil field makes this an area that is interesting both economically and geologically. In spite of detailed geological and geophysical investigations, information available on palynostratigraphy and geochemistry for the area is scanty. The aim of the present work was to investigate the palynological assemblages, mineralogy and geochemistry of the Surma Group (SG) sequences in Surma Basin, Bangladesh. Core samples (n = 188) were gathered from the wells following: Patharia well-5, Rashidpur well-1, Atgram well-IX, Habiganj well-1, Kailastila well-1 and Fenchuganj well-2. They were provided by BAPEX (Bangladesh Petroleum Exploration Company). X-ray Fluorescence (XRF), Atomic Absorption Spectrometry (AAS), Loss of Ignition (LOI), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used for geochemical and mineralogical study of shale samples. In the palynological study, the distributions of pollens and spores were determined. For data analysis, SPSS computer programme was used. Palynological assemblages of the Surma Group of sedimentary sequence of Bangladesh include taxa range in age from the lower Miocene to the Upper Miocene which can be potentially used in dating and correlation. The Lower Miocene interval is correlated with the Simsang Palynological Zone IV of Meghalaya, India and the Bengal Palynological Zone (BPZ) V. The Upper Miocene is correlated with the Simsang Palynological Zone IV of Meghalaya, India and the BPZ Zone V of Bengal. They were deposited in two types of paleoenvironments ranging from the brackish type to shallow marine to brackish. The sequence contains reworked palynomorphs of BPZ IV and III namely Meyeripollies naharkotensis, Polypodiesporites Oligocenecus, Palmepollenities Eocencus and ornamented Tricolpate pollen of the Eocene-Oligocene age which are mainly encountered in the lower Miocene sediments indicative of increased tectonic activity in the area. Geochemical ratios (SiO2/ Al2O3, Cu/Zn, Maturity = K2O+ Al2O3/Na2O+MgO, Rb/K2O, K2O/Na2O, Cr/Rb, Zr/Rb, V/Rb, Th/U etc.) were useful for determining grain size, maturity, tectonics and environment of deposition. High Ba enrichment was detected in the Patharia well-5 and showed high surface water productivity and diagenetic mobilisation. Tectonic descrimination was achieved using SiO2 and K2O/Na2O ratio. XRD analysis revealed the minerals kaolinite, illite, chlorite, illite/smectite (I/S) and kaolinite/smectite (K/S) mixed layers. Kaolinite/Smectite here reported for the first time in Bangladesh. Clay mineral analyses provided evidence for diagenesis. Smectite diagenesis and dehydration have contributed to the generation of overpressure in the Bhuban Formation in the Patharia well -5. Geochemical ratios of the present study from the Surma Basin is undoubtedly a powerful technique and can be applied to any sedimentary basin analysis to infer the palaeoenvironment, palaeoclimate and palaeotectonics.

Credit Rating Agencies (CRAs) play a key role in financial markets by helping to reduce informative asymmetry between lenders and investors, on one side, and issuers on the other side, with regard to the creditworthiness of banks or countries. This crucial role has expanded alongside financial globalisation and received an additional boost from Basel II which integrates the ratings of CRAs into the rules for setting weights for credit risk. Ratings adjustment tends to be sticky, lagging behind markets, and often overreact when they do change. This overreaction may have aggravated the recent financial crises, contributing to financial instability and cross-country contagion. Criticism has been especially directed towards the high degree of concentration of the ratings industry. Promotion of competition may require policy action at the international level to encourage the establishment of new agencies and to discover alternative rules or regulatory requirements in order to achieve promising results. The recent growth of Middle Eastern and North African countries (MENA) and their commercial banking system has increased the need of paying widespread attention to this region of the world. This thesis crucially identifies, and estimates, the robust determinants of credit ratings for MENA countries and their commercial banks, incorporating a set of bank level accounting and financial risk factors, as well as country-specific characteristics, including indicators for regulatory, supervision, legal and economic environments. The research contributes, firstly, to the theoretical literature on credit ratings industry by reviewing extant methodologies specifically as they apply to banks and sovereign countries. Secondly, it conducts a systematic, cross-country empirical investigation using panel data econometric methodology for the purpose of estimating MENA countries sovereign and bank credit rating models. Thirdly, it provides tangible and statistically significant evidence on the different factors that determines the estimation of credit ratings and influencing bank's risk. The extant literature reviewed serves as a basis to achieve and develop the research aim, objectives and hypotheses of the thesis. The research then constructs an appropriate panel dataset from different sources, containing bank-level and country-level information for a sample of 108 commercial banks covering 13 MENA countries over the period 2000 - 2012. The methodological framework for estimating credit rating models (linear regression, logit and probit) is also reviewed and the procedures for panel data estimation are implemented using the econometric package STATA (version 13). All relevant data are drawn from public sources including Reuters, Bankscope, IMF and the World Bank. Using the random effects ordered probit and logit methodologies to estimate both sovereign (country) and bank level credit ratings models for the MENA countries, the evidence shows that real GDP growth, capital requirements, restrictions on banking activities and control of corruption all contribute negatively to the sovereign ratings. Furthermore, internal management and organisational requirements is considered as an additional regulatory factor not studied in previous research. The statistically significant and inverse relationship of the latter is considered an important and interesting outcome of MENA countries’ sovereign ratings. On the other hand, GDP per capita, investment (as a percentage of GDP), political stability, government effectiveness and the rule of law all reveal significant and positive impact on the sovereign credit ratings. In general, this research finds that improved macroeconomic conditions are correlated with higher ratings, while greater reserve regulations are correlated with lower ratings. The study also does find the significance of governance and regulatory variables plays a key role into the final credit rating. With regard to the impact on banks’ ratings, the results show that higher return on average assets and equity, larger bank size, more restrictions on bank activities, as well as higher official disciplinary power and higher standards of internal management, will yield higher credit ratings. Apart from having direct and positive impact on banks credit ratings, these variables are important for examining the risk-sharing incentives in MENA countries’ banks. In contrast, the estimation results indicate that net interest margin, net loans to deposits, liquid assets to deposits, capital requirements, deposit insurance scheme, liquidity requirements, unemployment rate and government effectiveness have an inverse and negative impact on banks ratings. In general, this study also finds various financial, macroeconomic, and regulatory effects on banks’ credit ratings. To a much lesser extent than government ratings, various macroeconomic variables also helped predict banks’ ratings, including real GDP growth and the unemployment rate. The thesis concludes by arguing that the combined use of financial and non-financial factors for estimating credit ratings models supports the relevant hypotheses examined and adds value to all stakeholders in improving and obtaining a better quality of credit ratings. This study also demonstrates that a diversity of bank-level and country-level factors influence the MENA sovereign and bank ratings differently, implying that policy makers, regulators alongside rating agencies should distinguish the different environmental factors between nations before any judgment and issuance can be model of the ratings. To conclude, there is no study which exclusively investigates credit rating models for the MENA region exploiting the richness of the data and methodology employed, and the current research aims to fill this gap.

The purpose of this study is to test the relation, if any, between use of fair value measurement and reported performance ratios of the firms and finally its effect on CEO compensation in Sweden. This research aims to contribute knowledge of decision makers about the performance-pay link in Sweden by comparing the changes of CEO compensations across the years, before and after the use of fair value method. In this sense, firms divided in two models of ownership structure: firms with family concentration and firms with dispersed ownership structure. This paper intent to contribute the explanations of existing researches from the USA and China about exponential increase in CEO compensation after the use of fair value method, with the data of Swedish listed companies. The data set of this study was highly dependent of the accessibility of information. In this sense, this research can be contributed with different data set, with more detailed scrutinise of data and in a longer research period. / <p>Acknowledgements</p><p>Having completed this master thesis in Linnaeus University in 2017, I would like to thank several individuals. I would like to start by thanking Andreas Jansson, Associate Professor of Accounting and Logistics at Linnaeus University, who inspired me about the subject and my supervisor Fredrik Karlsson, Senior Lecturer of Accounting and Logistics at Linnaeus University, for his sincere assistance, guidance and immensely valuable criticisms.</p><p>I owe special thanks to Ozan Uyanık for proofreading my paper, for his never-ending support and his whole year patience and endurance at times of stress. Another special thanks to my friends Ayşegül Girgin Ring and Şeniz Yılmaz for their valuable advice in econometrics and statistics.</p>