Ecology of larval fishes and large zooplankton in the Keweenaw Current region of Lake Superior, with special focus on lake herring, Coregonus artedi

Oyadomari, Jason K Michigan Technological University 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

I assessed the influence of the Keweenaw Current and spring thermal bar on the distribution of larval fishes and large zooplankton in Lake Superior. In 1998 and 1999, samples were collected from inshore (0.2-3.0 km from shore) and offshore (5.0-9.0 km from shore) locations on three transects off the western coast of the Keweenaw Peninsula, Michigan. For larval fishes, density and size distribution patterns of lake herring (Coregonus artedi), rainbow smelt (Osmerus mordax), burbot (Lota lota ), deepwater sculpin (Myoxocephalus thompsoni), and spoonhead sculpin (Cottus ricei) suggest a seasonal inshore to offshore movement. For zooplankton, seasonal warming appeared to be the major factor that limited planktonic catches of the primarily benthic Mysis relicta and Diporeia spp., while simultaneously stimulated growth and reproduction of the cladocerans Daphnia spp., Holopedium gibberum, and Bythotrephes cederstroemi . In contrast, calanoid copepods as a group were abundant throughout the entire sampling season. The greatest abundances of zooplankton were generally encountered offshore, even for the cladocerans, which apparently expanded from inshore to offshore locations with seasonal warming. In 2000, sampling efforts focused on lake herring. Samples were collected from surface waters at 0.1-17.0 km from shore on two transects. Lake herring larvae were also reared in the laboratory from eggs in order to validate the use of otolith microstructure for aging. Increment deposition was not statistically different from a daily rate starting from 28 days after hatching, near the time of yolk-sac absorption, but larvae with lower growth rates could not be aged as accurately. In Lake Superior, lake herring tended to be slightly more abundant, larger, and older at inshore locations, but a dense patch of younger larvae was also encountered 7-13 km from shore. The distribution patterns suggest that larvae were transported by prevailing currents into the study region, possibly from the more productive spawning regions in western Lake Superior. Growth rates were suppressed at offshore locations where temperatures were less than 8°C. These results indicate that lake herring larvae may be transported far distances from spawning concentrations by longshore currents, and water temperatures may largely control their growth.

Log curve amplitude slicing: Visualization of well log amplitudes for paleogeographic reconstruction of the Middle Devonian Traverse Group, Michigan Basin

Wylie, Albert Sidney, Jr Michigan Technological University 2002 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Well log curve shapes and amplitude trends are routinely used to correlate and map formations and reservoirs across petroleum basins or fields. The methods typically employed for correlation and mapping fail, however, to make full use of the vertical resolution of well log curves. A new technique, log curve amplitude slicing (LCAS) facilitates correlation by generating a series of subhorizontal slices through the log curves using sample-by-sample analysis of log curve amplitudes in all wells between two correlative time-surfaces. The slices represent approximate time lines and are relative chronostratigraphic surfaces that can be gridded and contoured to show trends and patterns in log curve amplitudes in map view. When appropriate logs are used (e.g. gamma ray, photoelectric effect, resistivity), the slices show the inferred distribution of lithofacies at the time of deposition. Animation allows visualization of changes in the distribution of lithofacies between successive slices. The log curves can be sliced through the interval of interest from the top-down, from the bottom-up, or proportionally depending upon the sequence stratigraphic interpretation. Application of the LCAS technique facilitates correlation because it highlights trends in log curve amplitudes that are not apparent using traditional methods to display and compare log curves. Gamma ray log data from 199 wells are used in this dissertation to identify the location, relative timing, and extent of significant fine-grained clastic influx into the carbonate/evaporite-dominated Michigan Basin during deposition of the Middle Devonian Traverse Group. LCAS maps are combined with outcrop stratigraphy to reconstruct the depositional history of the Traverse Group and to develop a relative water depth curve for the Michigan Basin during the Middle Devonian. Comparison of the relative water depth curve to a eustatic sea level curve suggests that although sea level fall may have resulted in formation of several Middle Devonian unconformities, sediment supply/production and subsidence/uplift were important factors influencing Middle Devonian deposition in the intracratonic Michigan Basin. Lithofacies patterns observed in LCAS maps at the basin scale coincide with productive Traverse Group carbonate trends and reveal potentially new areas for exploration and exploitation.

Evaluating the long-term effects of logging residue removals in Great Lakes aspen forests

Premer, Michael I Michigan Technological University 2015 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Commercial aspen (Populus spp.) forests of the Great Lakes region are primarily managed for timber products such as pulp fiber and panel board, but logging residues (topwood and non-merchantable bolewood) are potentially important for utilization in the bioenergy market. In some regions, pulp and paper mills already utilize residues as fuel in combustion for heat and electricity, and progressive energy policies will likely cause an increase in biomass feedstock demand. The effects of removing residues, which have a comparatively high concentration of macronutrients, is poorly understood when evaluating long-term site productivity, future timber yields, plant diversity, stand dynamics, and consequently, appropriate silviculture. These practices were evaluated throughout the western Upper Peninsula of Michigan using forest inventory data from harvested stands over the last 45 years. Assessment provided a framework of ecosystem carbon patterns across stand rotation, and comparisons reflected moderate losses in residue-bound carbon pools when captured. However, residue loads exceeded those recommended by established residue retention guidelines even in stands where residues were recovered for bioenergy. Soil nutrient pools exhibited declines under residue removal treatments on coarse textured soils. Aboveground biomass and timber yields did not vary according to residue treatment, and development of the aspen cohort was similar across all soil types, regardless of nutrient levels, an unexpected result. Stand dynamics varied by soil productivity class in the late stages of stand rotation, and imply that encouragement of non-crop trees for ecological purposes does not affect yields of the aspen resource. Predictions based upon historical growth and yield models showed mixed levels of accuracy when compared to observations. Analyses of vegetation communities and multivariate ordination methods revealed temporal patterns in species richness and increased heterogeneity under residue removal treatments. A spatially explicit sampling design was utilized to examine advances in harvesting technology on variance in stand level regeneration, soil nutrients, and residue estimates. Operator and equipment induced patterns in harvesting activity were found to increase residue loads with a concomitant decline in stem density and height growth across a large portion of the regenerating stand. Collectively, these findings suggest that residue removal results in a minor decline in aboveground C stocks, and coarse textured soils may be susceptible to reductions in forest soil nutrient pools. Further, variations in growing conditions at the forest floor due to high residue loads may adversely affect understory vegetation communities. Finally, harvesting equipment, cut-block layout, and residue distribution can influence stand regeneration patterns, and warrants consideration in harvest and silvicultural planning.

Development and characterization of an improved luciferase with applications to in-vitro toxicity testing of high production volume chemicals

Choi, Eileen H. Kim Michigan Technological University 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The objective of this research was to develop an in-vitro system for assessing toxicity of high production volume (HPV) chemicals using North American firefly (P. pyralis) luciferase bioluminescence reaction with adenosine triphosphate (ATP) as an end point. A series of random mutagenesis and colony level screening methods were used to improve enzymatic properties of wild type luciferase. A chloroform resistant mutant luciferase CNBLuc03--06(S239T, D357Y, and A526T) was developed, purified, and characterized. Finally CNBLuc03--06 luciferase was applied to a cell-based assay system for assessing cytotoxicity of HPV chemicals, including chloroform and compared to wild type luciferase for its performance.

Visibly composed, or seeing what we make of our selves on paper and on screen

Wysocki, Anne Frances Michigan Technological University 1999 국내박사

Vibration analysis of constrained layered beams with multiple damping layers

Hao, Min Michigan Technological University 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

With an increasing demand for light, continuous, and high strength structures, multi-layered systems with viscoelastic materials have gained major importance over the years. Viscoelastic layered systems provide a simple and flexible solution for damping vibration of sheet metal panels. They also help to effectively eliminate noise from resonant structures and surfaces. There has been a lot of work done on active and passive layered sandwich beams based on the theoretical models proposed by Kerwin (1959) and extended by Ditaranto (1965), Mead and Markus (1969), and other researchers. This work presents an analytical formulation to predict the stiffness and damping of constrained layered beams that have multiple viscoelastic damping layers. The model was derived for symmetrical setups using variational methods. The equations to evaluate the stiffness and damping were derived in closed form and can be evaluated for different boundary conditions. The complex modulus approach was used to model the elastic and shear modulus of the viscoelastic material. The equations of motion for multi-layer system in this research were compared with Mead's three layer beam model. Equations derived in this dissertation match well with Mead's equation for symmetric system. A parametric analysis has been conducted to study the effects of different parameters on the damping and stiffness of the system under simply supported boundary conditions. In addition, another analytical model was developed for the unsymmetrical setups with two different viscoelastic materials adjacent to each other. Experiments were conducted on simply supported three-layered beams at different temperatures to validate theoretical results. The experimental results show good agreement with the modal frequencies estimated by theory. The first four modes were considered in the computation and experiment validation. The multi-objective optimization procedure to obtain optimum structural and material parameters corresponding to given temperature and frequency range for maximizing system damping and minimizing the system mass was also obtained. Using an illustrative example, it was shown that it is possible to arrive at a configuration that has maximum damping without sacrificing stiffness and weight requirements.

Fishery co-management opportunities between tribal and state agencies: Conflict to collaboration

Holtgren, J. Marty Michigan Technological University 2014 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Over the past 40 years global recognition has occurred for indigenous groups to be represented and have input in how natural resources are managed. This has largely occurred because of how management decisions have consequences to indigenous groups that reach beyond natural resource issues but into cultural, spiritual, social and political elements including sovereignty, legitimacy, justice, equity and empowerment and using indigenous paradigms to meet indigenous needs. In the United States numerous legal agreements have been reached that pair state and tribal agencies into co-management. This project concerns a recent co-management agreement between the State of Michigan and five Native American tribes where each has specific rights and responsibilities for fishery management. Using interview data collected from state and tribal participants and quantitative data from respective fishery agency work plans this Dissertation explores the co-management relationship, how well it is functioning, differences and similarities in participant values, worldviews, and perspectives, priorities for fishery biological assessment and restoration priorities and what the hopes for their co-management relationship. We found there was little understanding between state and tribal participants regarding how they understood each other's priorities for fishery management or the biological assessments and restoration activities they identified should occur. State and tribal participants viewed the fishery resource and the value of science in management differently through unique knowledge systems (Western scientific and indigenous). These knowledge systems likely accounted for the difference we found in how the agencies prioritized biological assessments and restoration activities. The state participants often described broad scale assessments and activities as a priority while tribal participants often described those that occurred near tribal reservations, benefit native species, and promoted treaty protected harvest rights. Participants identified barriers towards successful co-management and they stemmed from legal negotiations and a history of conflict that had hindered personal and professional relationships amongst the agencies. However, even with these barriers participants recognized the value of collaborating for fishery management and proposed how they believed an ideal relationship would and could function. We propose strategies that could assist the groups in realizing a successful co-management institution.

Evaluating northern hardwood management using retrospective analysis and diameter distributions

Pond, Nan C Michigan Technological University 2012 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Northern hardwood management was assessed throughout the state of Michigan using data collected on recently harvested stands in 2010 and 2011. Methods of forensic estimation of diameter at breast height were compared and an ideal, localized equation form was selected for use in reconstructing pre-harvest stand structures. Comparisons showed differences in predictive ability among available equation forms which led to substantial financial differences when used to estimate the value of removed timber. Management on all stands was then compared among state, private, and corporate landowners. Comparisons of harvest intensities against a liberal interpretation of a well-established management guideline showed that approximately one third of harvests were conducted in a manner which may imply that the guideline was followed. One third showed higher levels of removals than recommended, and one third of harvests were less intensive than recommended. Multiple management guidelines and postulated objectives were then synthesized into a novel system of harvest taxonomy, against which all harvests were compared. This further comparison showed approximately the same proportions of harvests, while distinguishing sanitation cuts and the future productive potential of harvests cut more intensely than suggested by guidelines. Stand structures are commonly represented using diameter distributions. Parametric and nonparametric techniques for describing diameter distributions were employed on pre-harvest and post-harvest data. A common polynomial regression procedure was found to be highly sensitive to the method of histogram construction which provides the data points for the regression. The discriminative ability of kernel density estimation was substantially different from that of the polynomial regression technique.

Intramolecular hydrogen bonding network in myo-inositol phosphates

Yang, Ping Michigan Technological University 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

This work describes a theoretical investigation of the leading role that intramolecular hydrogen-bonding network (intra-HBN) can play in the determination of the conformation of myo-inositol 2-monophosphate (Ins(2)P1) and myo-inositol 1,4,5-trisphosphate (Ins(1,4,5)P3). These compounds are members of the inositol phosphate family of compounds which are important participants in the role that phosphates play in biological and environmental chemistry. Additionally, these compounds serve as a model system for compounds having both hydroxyl and phosphate groups, such as RNAs and nucleotides. Special attention was paid to the intra-HBN within their anions and their complexes with the metal cations (Li+, Na +, K+, Mg2+, Ca2+). This allows the investigation of the total electrostatic perturbation to these systems that occur between the phosphate groups, the hydroxyl groups, and their hydrogen bonding network, the solvent and the counter ions. The results from our model systems will help to guide accurate simulations of proteins, RNAs and membrane structures that interact with cations at different pH and in different surrounding medium. The results show that the global minima of Ins(2)P1 and Ins(1,4,5)P 3 at different deprotonation states prefer the 1a/5e structures where the functional group on position 2 is in the axial position with all other five functional groups in the equatorial position. A novel four-center pattern of hydrogen bonding was found to stabilize the system. An intramolecular proton transfer across a low barrier hydrogen bond (LBHB) between a charged phosphate and hydroxyl groups was found. The conformations of the metal inositol phosphate complexes depend on the type of metal cation, deprotonation state, and dielectric environment. Metal ions are involved in the folding of proteins, DNA and RNA and have a special relationship with the phosphate group, PO43-. Particularly appealing is that these cations affect the intramolecular hydrogen bonding network and cause conformational change. This would be the first systematic study of the pH-dependent and solvent-dependent interactions between cations and the phosphate groups/hydrogen bonding network within biological systems. Our results show that both Ca2+ and Mg2+ appear to be unique in how they impose conformational changes in Ins(2)P 1 and Ins(1,4,5)P3 and their deprotonated anions.

Minimizing comminution overgrinding through mathematical modelling

Walqui Pantigoso, Henry Julio Michigan Technological University 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Overgrinding is a critical problem commonly encountered in size reduction circuits. Size reduction is seldom performed without one or more classification stages. In the case of heterogeneous ores, the difference in the classification properties of the ore has been found to greatly influence hydrocyclone performance. A study of an iron ore size reduction circuit processing magnetite identified the presence of a large fraction of fine valuable material in the hydrocyclone undertow feeding a pebble mill. The presence of fine material in the pebble mill feed resulted in reduced mill capacity and wasted energy. Laboratory and plant hydrocyclones experimental work was carried out to evaluate the effect of the difference in classification properties of the components of heterogeneous ores to understand this phenomenon and to develop methods to improve performance. During the experimental work, fine and coarse fish-hooks were observed on the hydrocyclone efficiency curves. Even though both anomalies in the efficiency curves had been previously observed, they had not been observed simultaneously; neither origin of these anomalies is fully understood. The results from the laboratory experiments indicated that the coarse fish-hook occurred due to the difference in size distribution and specific gravity of the components of heterogeneous ores and the operating conditions. Magnetic agglomeration, on the other hand, was responsible for an increase in the size of the fine fish-hook. Reviewing hydrocyclones theory, laminar flow was observed to have been assumed as the normal operating regime for hydrocyclones. The hydrocyclone experimental results indicated that the assumption of laminar flow might be an incorrect assumption for hydrocyclone models, and a correction to Plitt's hydrocyclone model was made to account for non-laminar flow. A second equation adjustment was made to model the coarse fish-hook because current model corrections are focused on fine fish-hooks rather than the coarse fish-hooks. Finally, a model for a size reduction circuit was used to examine an alternative circuit configuration based on the knowledge gained during the project.