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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
381

Filtering service recovery feedback : A Case study research at Handelsbanken, Uppsala city

Nolan, Neil, Rudström, David January 2008 (has links)
<p>Research has shown that companies encourage customers to complain and gather huge amounts of service recovery information, although most of this information isn´t used by the companies. Our purpose with this thesis is to explore what determines the filtering of service recovery feedback, and if possible to identify its underlying reasons. This was accomplished through a qualitative case study at Handelsbanken Uppsala City. Empirical material was mainly collected through interviews with the office manager, frontline employees, and the regional complaints manager. When analyzing the empirical material Tax and Brown model of service recovery was used as an analytical framework.</p><p>The analysis shows that the employees at Handelsbanken Uppsala city aren’t controlled by many guidelines and policies; instead emphasis is put on the independence, trust, and responsibility of each individual employee. This is probably due to the decentralized organization of Handelsbanken and the belief in the employee’s capability to better understand what is of importance to filter, due to their close interaction with customers.</p>
382

Plant responses after drainage and restoration in rich fens

Mälson, Kalle January 2008 (has links)
<p>Rich fens are an important, but threatened, habitat type in the boreal landscape. In this thesis I have examined responses of rich fen vascular plants and bryophytes after drainage and restoration. </p><p>The effects of drainage on the rich fen flora were observed in a long time study and the responses were rapid and drastic. During an initial stage a rapid loss of brown mosses was observed, followed by increases of sedges and early successional bryophytes, and later by an expansion of dominants. Initial effects of hydrological restoration showed that rewetting can promote re-establishment of an ecologically functional rich fen flora, but has to be combined with other treatments, such as mowing or surface disturbance. </p><p>After restoration, re-establishment of locally extinct species may be hampered by dispersal limitations. To test if reintroductions could help to overcome dispersal limitations I performed transplantation studies with four common rich fens bryophytes to a rewetted site. The results showed that the species were able to establish, and that survival and growth were promoted by desiccation protection and liming. </p><p>I further examined competition among three of the most common bryophytes in natural boreal rich fens that usually occur mixed in a mosaic pattern but show small but important microtopographical niche separation. The results indicate similar competitive abilities among the species, and no case of competitative exclusion occurred. The results help to explain the coexistence of these species under natural conditions with microtopographic variation and repeated small scale natural disturbances. </p><p>Restoring a functional flora in drained rich fens is a complex task, which requires understanding of underlying causes of substrate degradation in combination with suitable restoration measures. The thesis suggests how the results can be used in practical restoration work, and also stresses the need for monitoring of restoration experiments over longer time. </p>
383

EMIGRATORY BEHAVIOR OF ARIZONA AND BROWN TROUT AS A MEANS TO REGULATE POPULATION NUMBERS IN RESPONSE TO ENVIRONMENTAL CHANGES (COMPETITION, CARRYING, CAPACITY).

MESICK, CARL FREDERICK. January 1984 (has links)
The hypothesis that Arizona and brown trout regulate their numbers through the emigration of all individuals that are in excess of resources was tested experimentally. Different amounts of food and cover were provided to mixed sizes of trout in artificial stream channels with escape routes. The number of both species of trout that became resident generally varied in direct proportion to the amount of cover present; the numbers that established residency in either species stabilized in response to cover levels within 6 days. Emigratory behavior was much slower in response to food than to cover. The smallest Arizona trout showed the greatest decrease in numbers that established residency after being starved for 10 days; however they did not increase their numbers when food was increased above 30 g/day. Arizona trout over 14 cm SL and brown trout over 11 cm SL showed no change in the number of residents whether they were fed or starved for 69 days. There were consistent numbers of both species within 2 cm size intervals that became resident, suggesting that each size class independently regulates its numbers to its own resources. The small inter-replicate variance in numbers of trout that became resident at different levels of resources supports the hypothesis that Arizona and brown trout use emigration as a behavioral mechanism for self-regulation of numbers. The numbers of trout that became resident in channels with coexisting species were close to those observed in single species tests wherein resources were the same; immigrant brown trout were able to induce emigration in resident Arizona trout whereas immigrant Arizona trout seldom displaced resident brown trout. Therefore, theories concerning self-regulation of population numbers should be expanded to include an interspecific mechanism. Management practices such as stocking programs, habitat manipulation and multi-species fisheries can be ineffective unless the ramifications of population regulation are included in their design.
384

Watery Brown Rot of Vegetables in Arizona

Keener, Paul D. 01 1900 (has links)
No description available.
385

THE UTILIZATION OF INVERTEBRATE DRIFT AS A FOOD SOURCE BY ARIZONA TROUT, (SALMO APACHE) AND BROWN TROUT, (SALMO TRUTTA).

Billings, Rick Marvin. January 1982 (has links)
No description available.
386

Polyamines in Ecklonia maxima and their effects on plant growth.

Papenfus, Heino Benoni. January 2012 (has links)
Kelpak®, a seaweed concentrate (SWC) prepared from the brown seaweed Ecklonia maxima (Osbeck) Papenfuss, improves overall plant mass and fruit yield in a variety of crops. The main active principals isolated from Kelpak® are cytokinins and auxins. Although these compounds are partly responsible for the growth promoting effect observed with Kelpak® application, they do not fully account for the complete effect of Kelpak® treatment. For this reason the focus has turned to polyamines (PAs) which are found in all cells of plants, animals and microorganisms, including eukaryotic algae. Polyamines also have growth promoting effects in plants. A study was carried out to investigate the PA levels in E. maxima and Kelpak® through a biennial cycle and to investigate if the PAs present in Kelpak® may have an effect on root growth, alleviating nutrient deficiency and the transport and accumulation of PAs in plants. To determine the amount of PA in the stipes, fronds and SWC prepared from E. maxima, samples were collected monthly over a two-year period (June 2009-June 2011). Extracts were benzoylated and quantified using a Varian HPLC. Putrescine concentrations ranged from 15.98-54.46 μg.g⁻¹, 6.01-40.46 μg.g⁻¹ and 50.66-220.49 μg.g⁻¹ DW in the stipe, fronds and SWC, respectively. Spermine concentrations ranged from 1.02-35.44 μg.g⁻¹, 1.05-26.92 μg.g⁻¹ and 7.28-118.52 μg.g⁻¹ DW in the stipe, fronds and SWC, respectively. Spermidine concentrations fell below the detection threshold. This is the first report of PAs being detected in a SWC. The seasonal pattern established for the stipe, frond and SWC followed the same trend over a biennial cycle. Polyamines accumulated in the seaweed tissue during periods of active growth and as a stress response elicited by rough wave action. This PA trend was similar to the cytokinin trend reported by MOONEY and VAN STADEN (1984b) for Sargassum heterophyllum which suggests that PAs play an important role in the hormone cascade during active growth. Routine monthly screening of Kelpak® carried out in the Research Centre for Plant Growth and Development indicated that Kelpak® consistently resulted in more rooting in the mung bean bioassay than the IBA control. The potential root promoting effect of PAs were investigated. Individually applied PAs did not increase rooting in the mung bean bioassay, but a synergistic relationship was observed between Put (10⁻³ M) and IBA (10⁻⁴ M). When applied together, rooting increased significantly above Put (10⁻³ M) and IBA (10⁻⁴ M) applied separately. The Put-auxin combination produced a similar number of roots to those treated with Kelpak®. It is possible that the PAs present in Kelpak® have a synergistic effect with auxins present in Kelpak® to promote root development and growth. Several physiological effects of Kelpak® and PAs on plant growth were investigated in a series of pot trials. Kelpak® significantly improved the growth of P- and K-deficient okra seedlings and masked the detrimental effects exerted by P- and K-deficiency. The application of PAs (10⁻⁴ M) significantly improved the seedling vigour index (SVI) of okra seedlings subjected to N-deficiency. The statistical difference was attributed to the N-containing growth regulators and polyamines being degraded and metabolized by the okra seedlings. Polyamine application did not alleviate P- and K-deficiency but increased root growth significantly in seedlings receiving an adequate supply of nutrients. It is likely that the additional PAs supported auxin-mediated root growth. A pot trial with okra plants was conducted to establish if the PAs in Kelpak®, applied as a soil drench or foliar application, are absorbed and translocated in a plant. Plants were also treated with Put, Spm, Spd to establish if PAs can be absorbed and translocated. Once the fruit had matured, plants were harvested and the endogenous PA content quantified by HPLC in the roots, stems and fruits. Applying PAs as a soil drench was not as effective as a foliar spray at increasing the PA content in the different plant parts. Kelpak® treatment (0.4%) did not contribute more PAs in any plant part. Spermidine concentrations were higher, in the various plant parts, than Put or Spm, irrespective of the mode of application. The application of Put, Spd and Spm increased Spd concentrations in the roots. Considering that Spd is the main PA produced in the roots and that exogenously applied PAs are readily converted to Spd, it seems evident that Spd is the preferred PA for long-distance transport in plants. The cytokinins and auxins in Kelpak® play an important role in stimulating growth in plants. It is, however, the totality of different compounds in Kelpak® that gives it its unique growth stimulating ability. Polyamines, occurring within the seaweed contribute to this activity, having an active role in root production and thus increased plant growth. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
387

Studies of metal poor T dwarfs in UKIDSS

Murray, David Nicholas January 2013 (has links)
I have used blue near-infrared colours to select a group of UKIDSS T dwarfs with spectral types later than T4. From amongst these I identify two kinematic halo T-dwarf candi- dates. Blue near-infrared colours have been attributed to collisionally-induced hydrogen absorption, which is enhanced by either high surface gravity or low metallicity. Proper motions are measured and distances estimated, allowing the determination of tangential velocities. U and V components are estimated for our objects by assuming Vrad = 0. From this, ULAS J0926+0835 is found to have U = 62 kms−1 and V = −140 kms−1 and ULAS J1319+1209 is found to have U = 192 kms−1 and V = −92 kms−1. These values are consistent with potential halo membership. However, surprisingly, these are not the bluest objects in the selection. The bluest is ULAS J1233+1219, with J −K = −1.16±0.07, and surprisingly this object is found to have thin disc-like U and V . Our sample also contains Hip 73786B, which I find to be a companion to the star Hip 73786. Hip 73786 is a metal- poor star, with [Fe/H]= −0.3 ± 0.1 and is located at a distance of 19±0.7 pc. U, V,W space velocity components are calculated for Hip 73786A and B, finding that U = −48±7 kms−1, V = −75 ± 4 kms−1 and W = −44 ± 8 kms−1. From the properties of the pri- mary, Hip 73786B is found to be at least 1.6Gyr old. As a metal poor object, Hip 73786B represents an important addition to the sample of known T dwarf benchmarks. Using mid-infrared data from WISE, I also identify T dwarfs with abnormally-red H − W2 and consider possible causes for their extreme colours. In particular I exam- ine three prominent examples of this phenomenon, ULAS J1416+1348B, 2MASS J0939- 2448 and BD+01o 2920B. A plot of spectral type against MW2-magnitude suggests that ULAS J1416+1348B is potentially an unresolved binary, similar to 2MASS J0939-2448. However, the plot also indicates that BD+01o 2920B is not an unresolved binary. I also present new FIRE spectroscopy for ULAS J1416+1348B and 2MASS J0939-2448. These data show that ULAS J1416+1348B has a similar shape to the Y -band spectrum to that of BD+01o 2920B, thus suggesting that the two objects have a similar metallicity, whereas 2MASS J0939-2448 appears to be a more metal-rich object. Using a new parallactic dis- tance, I derive a luminosity of (6.9±0.7)×1020W for ULAS J1416+1348B. I also find a radial velocity of −39 ± 1 kms−1 for this object. The agreement between this and that of the L dwarf SDSS J1416+1348A confirms that these two objects are physically-associated. I also present a set of simulated unresolved binaries; the colours of these systems do not appear to redden significantly with the addition of cooler companions. From this, I suggest that the colours of ULAS J1416+1348B and BD+01o 2920B cannot be solely attributed to any possible unresolved companions; for these two objects, composition and/or surface gravity must be playing a substantial role. Consideration of model predictions provides extra evidence for this argument, showing as it does that high log g and low metallicity can redden H − W2 colours by as much as »0.5mag as compared to a high-metallicity and low log g object of the same effective temperature. I also present kinematics and photometry for several more new candidate low-metallicity T dwarfs. Spectra are also presented, where available. In addition I provide new follow-up JHK spectroscopy for ULAS J0926+0835, ULAS J1233+1219 and ULAS J1319+1209. These new spectra allow full JHK-based spectral typing for these objects.
388

How does parental contribution affect offspring performance in anadromous and resident brown trout, Salmo trutta L.?

Ashton, Jill Caroline January 2010 (has links)
The brown trout, Salmo trutta L., displays one of the most variable and polymorphic life-history strategies of all the salmonids. In some populations, individuals spend their whole life-cycle in the river (freshwater-resident) whereas in others, a varying proportion migrates to sea for variable amounts of time to better feeding conditions before returning to spawn (anadromous). The ‘decision’ if an individual will migrate or not will be determined by the balance of the costs and benefits of following a particular life-history strategy. The balance of these, which do not affect males and females equally, will determine the future success (measured by fitness) of each strategy. This research addresses the influences of parental contribution, mainly maternal effect, of anadromous and freshwater-resident brown trout on offspring performance and subsequent life-history. A partial migratory population of brown trout was studied in the Tadnoll Brook, one of the seven major tributaries on the River Frome. The tributary is classified as a circum-neutral chalk stream, 9.9 km long with a catchment approximately 50 km2. Carbon and nitrogen stable isotope analysis (SIA) was used to quantify maternal reproductive contribution of anadromous and freshwater-resident brown trout to offspring and determine the future success (measured by fitness) in terms of size and time of emergence. A panel of 12 microsatellite loci was used to assign parentage to 0+ parr. Using field data collected over 1.5 years on individual fish, this study tested parental influence on offspring performance in terms of size and growth rate and calculate the reproductive contribution of maternal/paternal anadromous and freshwater-residents. Adult life-history strategy was identified using a combination of results from SIA, PIT tag data and ecological data (body size, temperature). Parr life-history strategy (1+) was inferred using PIT tag detection data. The results of the SIA indicated fry of anadromous females emerged earlier and at a larger size than fry of freshwater-resident females. Parentage assignment of parr was low (28 %), with 8 parr assigned to both parents and 43 assigned to only a single parent. There was no detectable effect of parental life-history on parr size and growth rate, however the raw data may suggest offspring of anadromous parents have an early size advantage but a slower growth compared to offspring of freshwater-resident parents during the first year of the parr stage. Twenty-four percent of the offspring were identified as putative smolts at 2+ and both forms interbred and could produce offspring of each life-history. Estimates of reproductive contribution (SIA and growth) show a higher proportion of anadromous females and males (growth only) contributed to offspring production. The results of this research indicate that the maternal anadromous contribution is higher in the Tadnoll Brook population, affording fitness benefits to their offspring during early ontogeny such as size advantages and emerging at a more profitable time to establish feeding territories. Adult life-history does not appear to influence juvenile (0+ parr) life-history but may have an effect on offspring performance. The presence of both forms in the population suggests the anadromous fitness benefits to offspring may only have an affect during ontogeny and early stages of growth. Then after juveniles reach a size threshold environmental factors influence offspring life-history, resulting in the largest parr with the fastest growth adopting an anadromous life-history.
389

PHYSICAL AND CHEMICAL PROPERTIES OF AEROSOL PARTICLES IN THE TROPOSPHERE: AN APPROACH FROM MICROSCOPY METHODS

Gwaze, Patience 26 February 2007 (has links)
Student Number : 0318623R - PhD thesis - School of Geosciences - Faculty of Science / Physical and chemical properties of atmospheric particles are fundamental but not necessarily easily accessible parameters. Uncertainties in these parameters are responsible for some uncertainties associated with radiative impacts of aerosol particles in global climate models. The uncertainties pertain to limitations of sampling and measurement devices, difficulties in modelling aerosols (source strengths, spatial and temporal variability) and in understanding microphysical and optical properties of aerosol particles. Physical and chemical properties can be obtained at single-particle level by microscopy analyses of individual particles. Using refined analytical and interpretative techniques to derive some of these fundamental properties, aerosol particles collected in various field campaigns and laboratory experiments were investigated using two high resolution microscopes. The particles were collected during the LBA-EUSTACH, Large-Scale Biosphere-Atmosphere Experiment part of European Studies on Trace Gases and Atmospheric Chemistry; SMOCC campaign, Smoke Aerosols, Clouds, Rainfall and Climate; CTBH II, Cape Town Brown Haze II campaign; and a controlled combustion experiment. Microscopy techniques were compared and complemented with conventional techniques to characterise particle sizes, shapes, chemical compositions and mixing states. Particle size distributions were compared between geometric equivalent sizes measured from microscopes and aerodynamic equivalent diameters, while taking into account particle densities. Large differences were found between the particle sizing techniques. Microscopy sizes (3D) were systematically lower than expected, and depended on the relative humidity during particle sampling. Differences were attributed to loss of mass, presumably water adsorbed on particles. Losses were high and could not be accounted for by known humidity growth factors suggesting losses of other volatile compounds adsorbed on particles as well. Findings suggest that there are inherent problems in defining particle sizes with different sizing techniques, despite accounting for humidity growth of particles and particle density. For collected particles, there are mass losses on individual particles, as opposed to particle losses to walls during sampling. These losses will inevitably bias observed mass distributions derived from collected particles and hence their number-size distributions. Relatively young aggregated soot particles from wood combustion were investigated for particle morphology (fractality, specific mass) and dynamic properties. Based on a procedure that has been validated on modelled aggregates, several important parameters to characterise geometry and drag-to-mass relationship of aggregates were derived. Three techniques were used to derive fractal dimension of soot aggregates. Averaged fractal dimension was found to be Df = 1.82 ± 0.08. Dynamic shape factors of soot particles were 1.7 to 2.5 and increasing with mass of aggregates. In the regime 0.2 < Kn < 0.7 (Knudsen number, Kn = 2#21;/dmob) the mobility diameter dmob was observed to be proportional to the radius of gyration with a ratio dmob/2Rg = 0.81 ± 0.07. Specific surface area of aggregates was determined to be 70 ± 10 m2g−1 based on SEM image analysis. These parameters can be used directly in modelling microphysical behaviour of freshly formed soot particles from biomass combustion with fractal dimension of Df ≈ 1.80. Chemical composition and size distributions of particles were investigated on filter samples collected during intense winter brown haze episodes in Cape Town. The sampling technique offered the capability to characterise highly heterogeneous aerosols over a polluted urban environment. Based on morphology and elemental composition, particles were categorised into seven particle groups of: aggregated soot particles, mineral dust, sulphates (SO2− 4 ), sea-salt, tar balls/fly ash, rod-shaped particles associated with soot agglomerates and those that could not be attributed to any of these groups were labelled as ‘others’. Apportionments of chemical species were highly variable both spatially and temporally. These variations indicate lack of lateral mixing and dependence of particle chemical compositions on localised and point sources within the Cape Town area. Sulphate and aggregated soot particles were externally mixed with fractional number concentrations of 0− 82% and 11%−46%, respectively. Aerosol complex refractive indices were derived from the chemical apportionment and particle abundance determined in microscopy analyses. The refractive indices were combined with in-situ measurements of number-size distribution to determine optical properties of aerosols. Single scattering albedo, !0, varied from 0.61 to 0.94 with a mean value of 0.72±0.08. The !0 is much lower than is generally reported in literature, and this was attributed to high concentrations of highly absorbing anthropogenic soot observed in SEM analysis. The mean extinction coefficient #27;ep was 194 ± 195 Mm−1. #27;ep and !0 clearly demonstrated and explained quantitatively the visibility reduction due to particles in the Cape Town atmosphere, reduction observed as the brown haze phenomenon. In all the three case studies, microscopy single particle analysis played a critical role in advancing knowledge of understanding properties of aerosol particles in the atmosphere.
390

Central Control Of Body Fat And Thermoregulation Through Shared And Separate Sympathetic Circuitries And Sensory Feedback

Nguyen, Ngoc Ly 10 May 2017 (has links)
More than 30% of the population suffers from obesity, which increases the risk of death and secondary health problems. Body fat [white adipose tissue (WAT) and brown adipose tissue (BAT)] are innervated and regulated by the sympathetic nervous system (SNS). WAT stores energy, while BAT generates heat for thermoregulation. Fat also has sensory innervations, but the roles of sensory nerves are still being elucidated. Hence, understanding the neuroanatomy of the SNS innervations of fat and the neural regulation of fat metabolism will be valuable for advancing obesity treatment. Using trans-synaptic tract tracers with unique fluorescent proteins, we defined and compared the SNS innervations of visceral fat [mesenteric WAT (MWAT)] and subcutaneous fat [inguinal WAT (IWAT)] and of IWAT and interscapular BAT (IBAT) in Siberian hamsters. MWAT and IWAT have moderately shared SNS innervations within the hindbrain, but separate SNS innervations in rostral regions. In contrast, IWAT and IBAT have relatively separate SNS circuitries throughout the brain yet some overlap in SNS nuclei known to regulate thermogenesis. We tested for the presence of functional coordination between IWAT and IBAT defined by overlap in IWAT SNS and IBAT SNS innervations. When IBAT function was impaired by SNS denervation, IWAT SNS drive, thermogenic activity, and beige adipocyte recruitment increased in cold exposed hamsters likely through coordination with IWAT SNS pathways. Conversely, we found that only SNS drive to IWAT increased during acute food deprivation suggesting that populations of SNS neurons singly innervating each fat depot may contribute to differential SNS drive to fat. Lastly, we demonstrated that IWAT sensory nerves mediate the functional coordination between IWAT and IBAT and the regulation of SNS drive to fat. The absence of IWAT sensory feedback via sensory denervation differentially decreased SNS drive to IBAT and IWAT itself, but not to MWAT, retroperitoneal WAT, and epididymal WAT in cold exposed hamsters. Collectively, the studies in this dissertation provide neuroanatomical evidence of separate and shared SNS brain sites likely receiving sensory signaling and regulating SNS drive to fat, and direct evidence of the roles of SNS and sensory nerves innervating fat to energetic homeostasis and thermoregulation.

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