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Postharvest windthrow and recruitment of large woody debris in riparian buffersBahuguna, Devesh 05 1900 (has links)
Large woody debris (LWD) is an important component of forest ecosystems and provides structural complexity to small streams. Riparian buffers are intended to provide long term supplies of LWD, but post harvest windthrow often occurs. To document the impacts of windthrow in riparian buffers and identify the components needed for small stream LWD recruitment modeling, I sampled 39 small streams at the Malcolm Knapp Research Forest (MKRF) and on Vancouver Island. I took two basic approaches. In the small stream experiment at MKRF a series of small clearcuts were harvested in 1998 in a 70 year old second growth stand. I measured LWD in 10m and 30m buffer treatments, and in the unharvested control. I added samples in mature and old-growth stands for comparison. In the second approach, I retrospectively sampled buffers that were exposed by harvesting from 0-20yrs ago on southwestern and northeastern Vancouver Island. In both studies, all logs greater than 7.5 cm diameter at mid-creek, in decay class 1 to 4 that spanned at least part of stream channel width were measured. There was no significant difference in the number of spanning and in-creek logs in 10m and 30m buffer given the short term monitoring of woody debris in the buffers. The majority of windthrown trees were still suspended above the stream channel years after a windthrow event. The height above stream was negatively correlated with log decay class and the buffer age class. The number of logs was higher in immature stands than mature stands. As the stems per hectare in riparian stands increases, so does the frequency of spanning LWD. The frequency of logs in decay classes 3 and 4 was higher in older buffers, and deciduous LWD decayed more quickly than conifers. Interestingly, the log length was found to be shorter in advance stage of decay. Key elements in a conceptual model of LWD recruitment via windthrow are the geometry of initial log position, log size, species and decay rate.
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Design and synthesis of novel isoelectric buffersLalwani, Sanjiv Kumar Shankerdass 12 April 2006 (has links)
Hydrolytically stable, low- and high-pI isoelectric hydrogel membranes were
prepared from poly(vinyl alcohol) (PVA) as alternatives to polyacrylamide-based
isoelectric membranes that hydrolyze in acidic and basic solutions.
Low-pI membranes were made by attaching an isoelectric buffer of a welldefined
pI value (such as iminodiacetic acid, IDA, aspartic acid, ASP or glutamic acid,
GLU) to the PVA backbone and crosslinking the PVA strands, in situ. The pH in these
membranes does not change significantly with slight variations in the amount of
isoelectric buffer that gets incorporated. The pI values of these membranes were pI is greater then 1.7 but less then 2.0 (IDAPVA), pI is greater then 2.0 but less then 2.6 (ASPPVA) and pI was greater then 2.6 but less then 3.4 (GLUPVA).The membranes were used as anodic membranes in isoelectric trapping (IET) experiments. Sugars, cyclodextrins (CDs), and certain polyhydroxy compounds have pKa
values between 11.5 and 14. Thus, high-pI hydrogels were obtained by incorporating (i)
quaternary ammonium derivatives of Beta-CD (QCDPVA) (ii) quaternary ammonium groups and Beta-CD (CDQPVA) and (iii) quaternary ammonium groups alone (QPVA) into the crosslinked PVA hydrogels. All three membranes had pI values greater than 11 and
served as effective cathodic membranes for the IET of small ampholytic molecules and
proteins. In pH-biased IET, proteins are collected into solutions of isoelectric buffers that set the pH to keep the proteins in a charged state affording high solubility and preventing precipitation. Thus, a series of isoelectric buffers (biasers) with high buffering capacity, high conductivity, and pI values covering the useful pH 2-10 range are needed.
Two sets of such buffers were designed (i) with pI values between the pKa values of two carboxylic acid groups and (ii) with pI values between the pKa values of the conjugate acid form of two amine groups. Six of these buffers were synthesized and their synthesis was optimized. The products were obtained in their pure, isoelectric form and were extensively characterized.
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Postharvest windthrow and recruitment of large woody debris in riparian buffersBahuguna, Devesh 05 1900 (has links)
Large woody debris (LWD) is an important component of forest ecosystems and provides structural complexity to small streams. Riparian buffers are intended to provide long term supplies of LWD, but post harvest windthrow often occurs. To document the impacts of windthrow in riparian buffers and identify the components needed for small stream LWD recruitment modeling, I sampled 39 small streams at the Malcolm Knapp Research Forest (MKRF) and on Vancouver Island. I took two basic approaches. In the small stream experiment at MKRF a series of small clearcuts were harvested in 1998 in a 70 year old second growth stand. I measured LWD in 10m and 30m buffer treatments, and in the unharvested control. I added samples in mature and old-growth stands for comparison. In the second approach, I retrospectively sampled buffers that were exposed by harvesting from 0-20yrs ago on southwestern and northeastern Vancouver Island. In both studies, all logs greater than 7.5 cm diameter at mid-creek, in decay class 1 to 4 that spanned at least part of stream channel width were measured. There was no significant difference in the number of spanning and in-creek logs in 10m and 30m buffer given the short term monitoring of woody debris in the buffers. The majority of windthrown trees were still suspended above the stream channel years after a windthrow event. The height above stream was negatively correlated with log decay class and the buffer age class. The number of logs was higher in immature stands than mature stands. As the stems per hectare in riparian stands increases, so does the frequency of spanning LWD. The frequency of logs in decay classes 3 and 4 was higher in older buffers, and deciduous LWD decayed more quickly than conifers. Interestingly, the log length was found to be shorter in advance stage of decay. Key elements in a conceptual model of LWD recruitment via windthrow are the geometry of initial log position, log size, species and decay rate.
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Postharvest windthrow and recruitment of large woody debris in riparian buffersBahuguna, Devesh 05 1900 (has links)
Large woody debris (LWD) is an important component of forest ecosystems and provides structural complexity to small streams. Riparian buffers are intended to provide long term supplies of LWD, but post harvest windthrow often occurs. To document the impacts of windthrow in riparian buffers and identify the components needed for small stream LWD recruitment modeling, I sampled 39 small streams at the Malcolm Knapp Research Forest (MKRF) and on Vancouver Island. I took two basic approaches. In the small stream experiment at MKRF a series of small clearcuts were harvested in 1998 in a 70 year old second growth stand. I measured LWD in 10m and 30m buffer treatments, and in the unharvested control. I added samples in mature and old-growth stands for comparison. In the second approach, I retrospectively sampled buffers that were exposed by harvesting from 0-20yrs ago on southwestern and northeastern Vancouver Island. In both studies, all logs greater than 7.5 cm diameter at mid-creek, in decay class 1 to 4 that spanned at least part of stream channel width were measured. There was no significant difference in the number of spanning and in-creek logs in 10m and 30m buffer given the short term monitoring of woody debris in the buffers. The majority of windthrown trees were still suspended above the stream channel years after a windthrow event. The height above stream was negatively correlated with log decay class and the buffer age class. The number of logs was higher in immature stands than mature stands. As the stems per hectare in riparian stands increases, so does the frequency of spanning LWD. The frequency of logs in decay classes 3 and 4 was higher in older buffers, and deciduous LWD decayed more quickly than conifers. Interestingly, the log length was found to be shorter in advance stage of decay. Key elements in a conceptual model of LWD recruitment via windthrow are the geometry of initial log position, log size, species and decay rate. / Forestry, Faculty of / Graduate
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VEGETATION STRUCTURE, LIGHT AVAILABILITY, AND SEDIMENT DEPOSITION WITHIN SINKHOLE BUFFERS ASSOCIATED WITH TRACKED AND WHEELED VEHICLE TRAINING AT FORT KNOX, KENTUCKYPattumma, Klairoong 01 August 2011 (has links)
Heavy wheeled and tracked vehicle training has been conducted on portions of the landscape of Fort Knox, Kentucky for approximately 60 years. Fort Knox is located on the Kentucky Karst Plain and sinkholes are dominant features of this area. Sinkholes and karst terrain present an atypical problem in combination with this unique land use, potentially impacting downstream and local terrestrial environment. A study of the training area sinkhole complex was conducted as a first step toward mitigating the impact of military activities and reduces potential problems of sedimentation and water quality degradation. A total of 20 sinkholes within Training Areas 9 and 10 at the Fort Knox Military Reservation were randomly selected to represent the study area. The objective of this study was to determine the relationship between stand structural characteristics, understory light availability and understory vegetation in sinkhole riparian buffers and concentrated flow paths and with the amount of sediment entering sinkholes in the study area. Vegetation data were collected during the growing months of May and June in 2009. All regressions analyses for vegetative structures have r2 values between 0.000 to 0.308 indicating weak to no correlation among the variables. Light availability and percent herbaceous cover showed moderate and weak relationship in buffers (r = 0.547, p = 0.003) and flow paths (r = 0.164, p = 0.245). Sediment gained in splay areas showed no significant relationship to vegetation structure (r = 0.039 to -0.335). The relationship between sediment gained and mean percent herbaceous cover was not significant in flow paths (r = -0.172, p = 0.2341) or buffers (r = 0.130, p = 0.292). While the results of this study suggest the amount of the sediment depositing in the sinkholes was unrelated to observe variation in sinkhole vegetation, the relationship between overstory vegetation and understory vegetation within sinkholes was more noticeable. On site observations strongly suggest that concentrated flow paths were the primary conduits for sedimentation into splay areas. Therefore, management considerations pertaining to training areas should minimize flow paths leading to sinkholes. Best management practices for Fort Knox training areas should integrate these research findings, in addition to current knowledge of riparian buffers and training areas' management requirements.
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Ada code generation support for Google Protocol BuffersEkendahl, Niklas January 2013 (has links)
We now live in an information society where increasingly large volumes of data are exchanged between networked nodes in distributed systems. Recent years have seen a multitude of dierent serialization frameworks released to efficiently handle all this information while minimizing developer effort. One such format is Google Protocol Buers, which has gained additional code generation support for a wide variety of programming languages from third-party developers. Ada is a widely used programming language in safety-critical systems today. However, it lacks support for Protocol Buffers. This limits the use of Protocol Buffers at companies like Saab, where Ada is the language of choice for many systems. To amend this situation Ada code generation support for Protocol Buffers has been developed. The developed solution supports a majority of Protocol Buffers' language constructs, extensions being a notable exception. To evaluate the developed solution, an artificial benchmark was constructed and a comparison was made with GNATColl.JSON. Although the benchmark was artificial, data used by the benchmark followed the same format as an existing radar system. The benchmark showed that if serialization performance is a limiting factor for the radar system, it could potentially receive a significant speed boost from a substitution of serialization framework. Results from the benchmark reveal that Protocol Buffers is about 6 to 8 times faster in a combined serialization/deserialization performance comparison. In addition, the change of serialization format has the added benefit of reducing size of serialized objects by approximately 45%.
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Agricultural conservation buffers for breeding grassland birds in eastern MississippiAdams, Heidi Lynn 30 April 2011 (has links)
Periodic disturbance in CP33 habitat buffers is required to maintain early-successional plant communities for grassland birds. However, effects of disturbance on habitat suitability and nesting success of grassland birds are unknown. Furthermore, the grassland bird community and reproductive performance in CP33 habitat buffers may be influenced by the landscape context (e.g., edge habitat, surrounding land cover). My objectives for this study were to determine how periodic disturbance and the agricultural landscape mosaic influence the breeding grassland bird community in buffers, and how these same factors influence grassland bird nesting success and density in buffers. Data collected during line-transect surveys conducted in CP33 habitat buffers in northeast Mississippi during the 2007-2009 breeding seasons demonstrate periodic disturbance through prescribed burning and light strip-disking does not influence breeding bird diversity or density in buffers. Buffers with woodland at the non-crop edge, however, had the least grassland bird diversity. Dickcissels, one of the most abundant grassland bird species detected in buffers, had a lesser, though non-significant, density in woodland-bordered than in grassland-bordered buffers. I estimated nest success of Dickcissels and Red-winged Blackbirds using maximum likelihood approaches modeling daily survival rates of nests in Program MARK. Analysis results indicated periodic disturbance did not inform models of nest success for either species to an extent requiring inclusion in the best approximating model. Both species, however, had greater nest densities in control and burned buffers than in disked buffers, as well as adjacent to grassland and crop edges. Dickcissel nest success was associated negatively to proximity of developed areas and amount of land cover in crop production, and associated positively with nest height. Red-winged Blackbird nest success decreased with increasing distance from a crop edge and decreasing height of surrounding vegetation, but increased with greater amounts of ground cover. Results from this study will assist land managers with selecting land for enrollment in CP33 that will maximize producers’ conservation goals while minimally impacting crop production, as well as assist with development and refinement of USDA-NRCS Practice Standards, documentation of ecological benefits of federally subsidized conservation practices, and enhancement of wildlife benefits in agriculture-dominated landscapes.
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Feminist Characteristics as Buffers to Suicide Attitudes and IdeationOney, Kimberly Mikich 17 May 2006 (has links)
No description available.
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MODELING AND SIMULATION OF CLOCK DISTRIBUTION NETWORKS USING DELAY-LOCKED LOOPSRAVI, MAHESWARI S. 02 October 2006 (has links)
No description available.
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Utilization of a Dual-Wavelength Dye for the Characterization of pH Buffers under Hydrostatic PressureCallahan, Zachariah P. 09 October 2013 (has links)
No description available.
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