The major aim of this thesis project was to determine the variables that most explain the elevated mercury concentrations in lake trout (<i>Salvelinus namaycush</i>), a predatory aquatic fish species in some lakes in northwestern Canada. High mercury concentrations in lake trout in other regions have been associated with the biological features of the fish and various chemical and physical aspects of their aquatic ecosystems. Data including lake trout age, length, weight, and stable isotope values, water chemistry, latitude, and lake and watershed area were collected, compiled and then included in statistical analyses of the factors affecting mercury concentration in the muscle of lake trout from a series of lakes from the Mackenzie River Basin (MRB) in the Northwest Territories (NT), Canada. These results are reported in Chapter 2. Fish age and lake surface area were the most important variables affecting mercury concentrations. However mercury concentration in muscle also was significantly (p < 0.05) related to: fish length, weight, and δ13C; watershed area to lake area ratio; and to total mercury concentration in zooplankton and water. These variables were run through best subsets analyses and multiple regressions in order to determine the regression equation most efficiently capable of predicting mercury concentration in lake trout in unstudied lakes in the MRB region. The resulting equation was: log Hg = 0.698 (0.0156 × latitude) + (0.0031 × age) + (0.000535 × length) (0.245 × log lake area) + (0.00675 × watershed area/lake area ratio), r2 = 0.73<p>Small lakes located in the southern NT and dominated by large and/or old lake trout are most likely to have lake trout whose mean mercury concentrations exceed 0.5 μg/g; the guideline for the commercial sale of fish. Latitude may be linked to mean annual temperature (and variables such as duration of ice cover, summer water temperature) while fish age and length may be related in part to fishing pressures and growth rates on these lake populations. In chapter 3, a more in-depth study was undertaken to investigate of role of feeding and relative tropic level in the bioaccumulation of mercury in lake trout. This was accomplished by comparing MRB lake trout population characteristics with those from a series of lakes in northern Alberta and Saskatchewan (NAS). The two population groups were compared with respect to size, age, growth rates, and mercury concentrations. In addition, trophic and mercury biomagnification relationships, as inferred from stable carbon and nitrogen isotope analyses, for the two lake trout populations were compared. Lake trout from the NT exhibited significantly higher mercury concentrations than those from the NAS lakes (p < 0.001). Mercury concentrations in biota (including lake trout, forage fish, benthic invertebrates and zooplankton) were positively and significantly correlated to δ15N values in all lakes in both of the study areas (p < 0.001). Mercury biomagnification in the NT lakes, as estimated from the slope of δ15N versus mercury concentration, was lower than in the NAS lakes. Thus, mercury biomagnifies more slowly in NT lake trout, but because of their greater mean age, reaches higher values than in NAS lakes. Northwest Territory lake trout generally exhibited more negative δ13C values, indicating more pelagic feeding habits than in NAS lakes: higher mercury concentrations previously have been associated with more pelagic feeding. <p>Finally, the relationship between mercury levels and growth rates in lake trout was investigated by comparing NAS and NT lake trout populations. These results are reported in chapter 4. Lake trout from the NT lakes grew at a slower rate (10.4 mm per year) than those from the NAS lakes (35.1 mm per year). Log mercury concentration was inversely correlated (p < 0.001) with growth rate for both lake trout populations; however, growth rate explained more of the variation in mercury level in the NT lakes than in the NAS lakes (NT, r2 = 0.11, p < 0.001; NAS, r2 = 0.03, p = 0.024). However, the correlation between mercury concentration and growth rate in the NAS study area improved when Reindeer Lake, possibly affected by anthropogenic inputs, was removed from the analyses (r = 0.13, p = 0.001). Therefore, lower mercury levels in lake trout are associated with higher growth rates through growth dilution. The higher mercury concentrations in NT lake trout are due not only to the old age of the fish, but to slower growth rates as well.

The major aim of this thesis project was to determine the variables that most explain the elevated mercury concentrations in lake trout (<i>Salvelinus namaycush</i>), a predatory aquatic fish species in some lakes in northwestern Canada. High mercury concentrations in lake trout in other regions have been associated with the biological features of the fish and various chemical and physical aspects of their aquatic ecosystems. Data including lake trout age, length, weight, and stable isotope values, water chemistry, latitude, and lake and watershed area were collected, compiled and then included in statistical analyses of the factors affecting mercury concentration in the muscle of lake trout from a series of lakes from the Mackenzie River Basin (MRB) in the Northwest Territories (NT), Canada. These results are reported in Chapter 2. Fish age and lake surface area were the most important variables affecting mercury concentrations. However mercury concentration in muscle also was significantly (p < 0.05) related to: fish length, weight, and δ13C; watershed area to lake area ratio; and to total mercury concentration in zooplankton and water. These variables were run through best subsets analyses and multiple regressions in order to determine the regression equation most efficiently capable of predicting mercury concentration in lake trout in unstudied lakes in the MRB region. The resulting equation was: log Hg = 0.698 (0.0156 × latitude) + (0.0031 × age) + (0.000535 × length) (0.245 × log lake area) + (0.00675 × watershed area/lake area ratio), r2 = 0.73<p>Small lakes located in the southern NT and dominated by large and/or old lake trout are most likely to have lake trout whose mean mercury concentrations exceed 0.5 μg/g; the guideline for the commercial sale of fish. Latitude may be linked to mean annual temperature (and variables such as duration of ice cover, summer water temperature) while fish age and length may be related in part to fishing pressures and growth rates on these lake populations. In chapter 3, a more in-depth study was undertaken to investigate of role of feeding and relative tropic level in the bioaccumulation of mercury in lake trout. This was accomplished by comparing MRB lake trout population characteristics with those from a series of lakes in northern Alberta and Saskatchewan (NAS). The two population groups were compared with respect to size, age, growth rates, and mercury concentrations. In addition, trophic and mercury biomagnification relationships, as inferred from stable carbon and nitrogen isotope analyses, for the two lake trout populations were compared. Lake trout from the NT exhibited significantly higher mercury concentrations than those from the NAS lakes (p < 0.001). Mercury concentrations in biota (including lake trout, forage fish, benthic invertebrates and zooplankton) were positively and significantly correlated to δ15N values in all lakes in both of the study areas (p < 0.001). Mercury biomagnification in the NT lakes, as estimated from the slope of δ15N versus mercury concentration, was lower than in the NAS lakes. Thus, mercury biomagnifies more slowly in NT lake trout, but because of their greater mean age, reaches higher values than in NAS lakes. Northwest Territory lake trout generally exhibited more negative δ13C values, indicating more pelagic feeding habits than in NAS lakes: higher mercury concentrations previously have been associated with more pelagic feeding. <p>Finally, the relationship between mercury levels and growth rates in lake trout was investigated by comparing NAS and NT lake trout populations. These results are reported in chapter 4. Lake trout from the NT lakes grew at a slower rate (10.4 mm per year) than those from the NAS lakes (35.1 mm per year). Log mercury concentration was inversely correlated (p < 0.001) with growth rate for both lake trout populations; however, growth rate explained more of the variation in mercury level in the NT lakes than in the NAS lakes (NT, r2 = 0.11, p < 0.001; NAS, r2 = 0.03, p = 0.024). However, the correlation between mercury concentration and growth rate in the NAS study area improved when Reindeer Lake, possibly affected by anthropogenic inputs, was removed from the analyses (r = 0.13, p = 0.001). Therefore, lower mercury levels in lake trout are associated with higher growth rates through growth dilution. The higher mercury concentrations in NT lake trout are due not only to the old age of the fish, but to slower growth rates as well.

Ontario cage culture operations produce the majority of farmed rainbow trout in Canada, using a diverse range of management practices that are expected to result in substantial variation in trout performance across the industry. A preliminary survey of performance data was undertaken, resulting in data from 5 commercial sites between 2008 and 2012. Commercial performance was somewhat poorer than expected, particularly for mortality rates, thermal-unit growth coefficients, and economic feed conversion ratios (average weighted values of 12%, 0.165, and 1.36, respectively). Substantial variability in all performance parameters within and across operations suggests that continued production monitoring and benchmarking could be highly valuable for improving the economic sustainability of the sector. For future benchmarking efforts to be effective, improvement and standardization of data collection methods is needed. As such, a number of recommendations are provided to the industry for the refinement and standardization of performance recording protocols used by Ontario producers.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-07-24T17:57:55Z No. of bitstreams: 2 marcos_aurelio_miranda_ferreira.pdf: 1389019 bytes, checksum: f995d3e92e9306d21b85ae68310ebc95 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-07-28T17:59:35Z (GMT) No. of bitstreams: 2 marcos_aurelio_miranda_ferreira.pdf: 1389019 bytes, checksum: f995d3e92e9306d21b85ae68310ebc95 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-28T17:59:35Z (GMT). No. of bitstreams: 2 marcos_aurelio_miranda_ferreira.pdf: 1389019 bytes, checksum: f995d3e92e9306d21b85ae68310ebc95 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A produ??o de novos conhecimentos sobre o crescimento e o ac?mulo de nutrientes ao longo do ciclo de desenvolvimento da planta de batata-doce pode auxiliar no ajuste da aduba??o, no aumento da efici?ncia dos recursos produtivos e, consequentemente, na eleva??o da sua produtividade. Neste sentido, o objetivo do trabalho foi caracterizar o crescimento, determinar a melhor ?poca de colheita e o ac?mulo de nutrientes na cultura da batata-doce. O experimento foi realizado no campus - JK da Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM, em Diamantina ? MG, utilizando o gen?tipo de batata-doce denominado ?Espanhola?. O delineamento adotado foi o de blocos casualizados, com quatro repeti??es. Os tratamentos foram 12 ?pocas de amostragens, realizadas com intervalos de 15 dias, para a coleta de tr?s plantas centrais da parcela. As plantas colhidas foram fracionadas em ra?zes, caule, folhas, e levadas ? estufa de circula??o for?ada para determina??o das respectivas massas secas. A massa seca e a ?rea foliar foram utilizadas para estimativa de ?ndices fisiol?gicos de crescimento. A partir da massa seca, tamb?m foram determinados os teores dos nutrientes. A quantidade de nutriente acumulado foi determinada multiplicando - se a massa seca pelo teor de cada nutriente. Os dados obtidos nas avalia??es de cada caracter?stica foram analisados por meio de regress?o. A planta de batata-doce apresentou maior crescimento entre 75 e 156 dias ap?s o transplantio (DAT). A ?poca de colheita mais adequada varia conforme a finalidade de uso. Para a obten??o de maiores produtividades totais e comerciais de ra?zes, a colheita deve ser realizada aos 180 DAT, enquanto que a parte a?rea (ramas) deve ser colhida entre 60 e 87 DAT. O ac?mulo de nutrientes variou conforme o ?rg?o analisado. A ordem decrescente de ac?mulo de nutrientes pelas ra?zes foi: N > K > Ca > P > Mg > S > Fe > Cu > Zn > Mn; parte a?rea: N > K > Ca > Mg > P > S > Fe > Mn > Zn > Cu; e total da planta (ra?zes + parte a?rea): N > Ca > K > P > Mg > S > Fe > Mn > Cu > Zn, considerando o per?odo de avalia??o de 15 a 180 DAT. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / The production of new knowledge about growth and accumulation of nutrients throughout the development cycle of the sweet potato plant can help adjust fertilization, increase the efficiency of the productive resources and, consequently, increase its productivity. In this sense, the objective of the work was to characterize the growth, determine the best harvesting season and the accumulation of nutrients in the sweet potato crop. The experiment was carried out at the campus - JK of the Federal University of Vales do Jequitinhonha e Mucuri ? UFVJM, in Diamantina - MG, using the sweet potato genotype named Espanhola. A randomized block design with four replications was applied. The treatments were 12 sampling times, conducted at intervals of 15 days for the collection of three central plants of the plot. The plants were harvested and fractionated into roots, stem, leaves, and taken to a forced circulation oven to determine their respective dry masses. The dry mass and leaf area were used to estimate physiological growth rates. The nutrient contents were also determined from the dry mass. The amount of nutrient accumulated was specified by multiplying the dry mass by the content of each nutrient. The data obtained in the evaluations of each characteristic were analyzed by means of regression. The sweet potato plant presented the highest growth between 75 and 156 days after transplanting (DAT). The most suitable harvesting season varies depending on the purpose of its use. In order to obtain the greatest commercial and total yields of roots, the harvest should be performed at 180 (DAT), while the aerial parts (branches) should be harvested between 60 and 87 DAT. The accumulation of nutrients varied in accordance with the organ analyzed. The decreasing order of nutrient accumulation by the roots was: N> K> Ca> P> Mg> S> Fe> Cu> Zn> Mn; Aerial part: N> K> Ca> Mg> S> Fe> Mn> Zn> Cu and total of plant (roots + aerial part): N> Ca> K> P> Mg> S> Fe> Mn> Cu > Zn, considering the evaluation period from 15 to 180 DAT.

No description available.

It is important to evaluate periodic fluctuations in environment or climate recorded through time to better understand the nature of Earth's history as well as to develop ideas about what the future may hold. There exist numerous proxies by which these environmental patterns can be demonstrated and analyzed through various time scales; from sequence stratigraphic bundles of transgressive-regressive cycles that demonstrate eustatic changes in global sea level, to the geochemical composition of a skeleton that records fluctuations in ocean temperature through the life of the biomineralizing organism. This study examines some of the methods by which we can analyze environmental fluctuations recorded at different time scales. The first project examines the methods by which extrabasinal orbital forcing (i.e. Milankovitch cycles) can be tested in the rock record. In order to distinguish these patterns, computer generated carbonate rock records were simulated with the resulting outcrops tested using common methods. These simulations were built upon eustatic sea level fluctuations with periods similar to what has been demonstrated in the rock record, as well as maintaining the many factors that affect the resultant rock composition such as tectonics, subsidence, and erosion. The result demonstrated that substantially large sea level fluctuations, such as those that occur when the planet is in an icehouse condition, are necessary to produce recognizable and preservable patterns that are otherwise overwhelmed by other depositional factors. The second project examines the temporal distribution of the bivalve Semele casali from Ubatuba Bay, Brazil by using amino acid racemization (AAR) calibrated with ¹⁴C radiometric dates. This data set is one of the largest ever compiled and demonstrates that surficial shell assemblages in the area have very long residence times extending back in time 10,000 years. The area has had very little change in sea level and the AAR ratios which are highly temperature dependent could be calibrated across sites varying from 10 to 53 meters in water depth. Long time scales of dated shells provide us with an opportunity to study climate fluctuations such as El Niño southern oscillation. The third project describes a newly developed method for estimating growth rates in organisms using closely related species from similar environments statistically analyzed for error using a jackknife corrected parametric bootstrap. As geochemical analyses get more precise while using less material, data can be collected through the skeleton of a biomineralizing organism, thus revealing information about environmental shifts at scales shorter than a year. For such studies, the rate of growth of an organism has substantial effects on the interpretation of results, and such rates of growth are difficult to ascertain, particularly in fossilized specimens. This method removes the need for direct measures of growth rates and even the most conservative estimates of growth rates are useful in constraining the age ranges of geochemical intra-skeletal studies, thus elucidating the likely time period under analysis. This study assesses the methods by which periodic environmental fluctuations at greatly varying time scales can be used to evaluate our understanding of earth processes using rigorous quantitative strategies. / Ph. D.

Using data from government sources (FRED, BEA, BLS), the thesis explores the underlying reasons for declining U.S. economic growth. A long standing trend of annual 3% growth no longer seems to hold true for the economy. The paper summarizes current theory as to why the growth has slowed and finds new explanations by analyzing the various major industries which make up GDP. The results show that sectoral shifts in employment from high paying industries to low paying industries help to explain a significant portion of the decline in national growth rates. The decline in growth is primarily driven by about ten poor performing states.

The purpose of this paper is to observe and analyze whether the value system and political structure of a nation, gauged through its legal configuration, impacts its response to IMF debt and consequently impacts its GDP growth rates. This paper also analyzes whether involvement in the fund through a loan relationship affects the country’s real interest rate, inflation, exchange rate and import and export volume and whether this relationship is causal in that we can explain a nation’s loan relationship with the Fund through observance of the aforementioned variables. In this paper, we observe 34 emerging markets as defined by Dow Jones in 2010. The general consensus of the literature is that participation in IMF loan programs retards the economic growth of developing economies. In light of this, the contribution of this paper is to illustrate that some of the slowed growth experienced by these countries seeking out IMF debt is explained by their value system and general attitude toward debt. To carry out a comparable analysis we segment and group the emerging markets based on their current credit status with the IMF (as of Oct 2012) as well as by the origin of their legal system, a measure we use to assess their value system with respect to creditor and debt protection laws. We will observe the growth rates that these countries’ economies experience categorized by their involvement with the Fund, the amount of their loan and whether they fully repaid their debt or are currently indebted to the Fund. We will also identify the size and frequency of the loan in order to observe the impact that these variables have on the delayed growth rates that they experience. Furthermore, we will examine the impact on their GDP growth rates, imports of goods and services, inflation, exchange rates and real interest rates. We expect to find that there is not a generic relationship between involvement in a loan relationship with the Fund and GDP growth rates. In other words, having a loan from the IMF does not directly result in delayed growth rates, contrary to popular belief. However, we hypothesize that the legal system of the borrowing countries is an explanatory variable in determining their growth rates, alongside their loan relationship with the Fund. In addition, we expect to find empirical evidence that supports the claim that inappropriate and unmonitored involvement in the Fund can adversely affect emerging markets. Inappropriate and unmonitored involved is measured in this paper by the borrowers creditor and debtor protection laws. We aim to expand the current line of literature by analyzing whether a decline in economic growth prior to completion of an IMF loan program is a generic attribute of all participants or whether these traits are more pronounced in countries with a more unmonitored business and economic legal system.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-02-20T18:25:57Z No. of bitstreams: 1 2017 - F?bio Ferreira Cruvinel.pdf: 1438823 bytes, checksum: 49768f1c89baea668d06d925b16c5e0c (MD5) / Made available in DSpace on 2018-02-20T18:25:57Z (GMT). No. of bitstreams: 1 2017 - F?bio Ferreira Cruvinel.pdf: 1438823 bytes, checksum: 49768f1c89baea668d06d925b16c5e0c (MD5) Previous issue date: 2017-02-21 / CAPES / The pitaya (Hylocereus undatus (Haw.) Britton & Rose) has an exotic shape, pleasant taste, easy digestibility and antioxidant properties, which have given greater demands in the Brazilian market for this fruit in recent years. The production of seedlings is a determining factor for the successful installation of pitaias orchards and the use of phytoregulators such as BAP (6-benzylaminopurine) and organic substrates, such as millipede-compost, in the production of seedlings of this fruit is still little reported. The objective of this work was to analyze the effect of BAP and millipede-compost on the production of pitaia seedlings. Pitaia cuttings from Fazendinha Agroecol?gica - Km 47, in the town of Serop?dica-RJ, were used. The stakes were standardized with 20 cm in length. The experiment with the phytoregulator was conducted in the greenhouse sector of the UFRRJ and the cuttings planted in substrate composed of sand and bovine manure in a ratio of 1: 1 by volume in a completely randomized design (DIC) in a factorial scheme (2X4) with 4 replicates: (2) By immersion and incision made at the apex of cladodes stakes versus (4) four doses of BAP (0, 50, 100 and 150 mg.L-1) were applied. Non-destructive Growth Analysis was performed and the simple correlations were calculated with the climatic data obtained at the Ecologia Automatic Station in Serop?dica-RJ. For the experiment with the millipede compost, the cutting was conducted in pots with three types of substrates: Gongocomposto, Biomix? and sand + bovine manure (1: 1 by volume) in DIC with five replicates. The results showed a linear tendency in number of shoots and quadratic tendency in other parameters (length, fresh and dry weight) evaluated with use of BAP. There was a correlation between the growth rates of the pitaya with the data of Global Solar Radiation of the 19h (22h UTC) period. The use of the gongocomposto showed larger and more vigorous plants of pitaia. / O fruto da pitaieira (Hylocereus undatus (Haw.) Britton & Rose) apresenta forma ex?tica, sabor agrad?vel, f?cil digestibilidade e propriedades antioxidantes, caracter?sticas essas que proporcionaram maiores demandas no mercado brasileiro por essa fruta nos ?ltimos anos. A produ??o de mudas ? um fator determinante para o sucesso da instala??o de pomares de pitaias e o uso de fitorreguladores como o BAP (6-benzilaminopurina) e substratos org?nicos, como o gongocomposto, na produ??o de mudas desta frut?fera ainda ? pouco relatado. O objetivo deste trabalho foi analisar o efeito do BAP e gongocomposto na produ??o de mudas de pitaia. Utilizaram-se estacas de pitaieira proveniente da Fazendinha Agroecol?gica ? Km 47, no munic?pio de Serop?dica-RJ. As estacas foram padronizadas com 20 cm de comprimento. O experimento com o fitorregulador foi conduzido no setor de olericultura da UFRRJ, em casa de vegeta??o e as estacas plantadas em substrato composto por areia e esterco bovino na propor??o 1:1 em volume em Delineamento Inteiramente Casualizado (DIC), com 4 repeti??es, em esquema fatorial (2X4), sendo (2) por imers?o e incis?o feita no ?pice das estacas dos clad?dios versus (4) quatro doses da citocinina BAP (0, 50, 100 e 150 mg.L-1). Foi realizada a An?lise de Crescimento n?o destrutiva e foram calculadas as correla??es simples com os dados clim?ticos obtidos na Esta??o Autom?tica Ecologia em Serop?dica-RJ. Para o experimento com o gongocomposto a estaquia foi conduzida em vasos com tr?s tipos de substratos: Gongocomposto, Biomix? e areia+esterco bovino (1:1 em volume) em DIC com cinco repeti??es. Os resultados mostraram uma tend?ncia linear positiva no n?mero de brota??es e quadr?tica para o incremento de comprimento, peso fresco e seco das brota??es para o uso da citocinina BAP no incremento de. Houve correla??o entre as taxas de crescimento da pitaia com os dados de Radia??o Solar Global do per?odo das 19h (22h UTC). O uso do gongocomposto proporcionou maiores e mais vigorosas mudas de pitaieira.

Leaf photosynthetic measurements using a portable 14Co2 field system were carried out and correlative leaf relative growth rates, RGR, were determined at different leaf positions of three alpine plant species throughout the growing season. Initially there was a period of high leaf RGR associated with a period of increasing photosynthetic activity. Following this stage was a long period of no net change in length of the living leaf. During this period, photosynthetic activity generally increased to a maximum level and then decreased steadily. The final ontogenetic stage was a period of negative leaf RGR denoting leaf senescence which was associated with a marked decline in leaf Co2 uptake. Ontogenetic timing of these alpine species is geared with the surge and decline of individual leaf photosynthetic activity so that one to several leaves operating at near maximal photosynthetic capacity are always maintained during the growing season for each plant. These findings are discussed in relation to their adaptive significance for these species.