4,704 research outputs found
New diatom taxa from the world’s first marine Bioblitz held in New Zealand: Skeletomastus a new genus, Skeletomastus coelatus nov. comb. and Pleurosigma inscriptura a new species
Diatoms were investigated as part of the world’s first marine Bioblitz held on the south coast of Wellington, New Zealand, in October 2007. Two unusual diatoms were associated with the red alga Herposiphonia ceratoclada. They were examined by light and scanning electron microscopy. The first, previously described as »Cocconeis coelata« Arnott ex Greville, is a thick-ribbed biraphid diatom that appears to have an undular raphe and marginal septum like some Mastogloia species, but it does not have partecta in the valvocopula. Instead it has short marginal ribs that support a pseudoseptum. Its solid lyre and multiseriate striae with cibrate pores could be modifications of similar structures in Aneumastus aksaraiensis Spaulding et al. It typifies the new genus Skeletomastus which appears to be close to both Mastogloia and Aneumastus, hence the name. The second is a proposed new Pleurosigma species, P. inscriptura with naviculoid symmetry and a markedly sigmoid raphe system with deflected ends. It appears bright blue in darkfield illumination which helped us locate it in other samples from theWellington region.We compare it with some other Pleurosigma species and consider their diffraction properties
Esthetic and Recreational Potential of Small Naturalistic Streams Near Urban Areas
The purpose of this study was to find a way to evaluate the esthetic and recreational potential of small streams and their watersheds. Research was limited to naturalistic streams with drainage areas under 100 square miles and located within 25 miles of a city. A methodology, based on some previous work of the U.S. Soil Conservation Service and the principles or concepts of terrain analysis, land use planning, value Judgment philosophy and the economics of outdoor recreation, was developed and applied in detail to two streams (Boone and Jessamine Creeks) near Lexington, Kentucky.
Evaluations were made of the streams\u27 potential for camping (primitive, transient and group), fishing, picnicking, a trail system (hiking, horseback riding, bicycling and auto tour routes), esthetic enjoyment (sightseeing, nature walks and walking for pleasure) and the establishment of natural, scenic and historic areas, Limited applications were also made to two other watersheds and to selected recreation sites on Boone and Jessamine Creeks. Extensions of these case studies resulted in procedures for estimating: visitation to a developed site, future participation demand generated by an urban area and the proportion of that demand that would be satisfied at a specific site, and the economic benefits that would accrue if the sites were developed.
Conclusions reached were: (1) Esthetic and recreational values can be identified, inventoried and used to evaluate a watershed\u27s development potential. (2) The methodology yielded fairly accurate evaluations for most of the recreational activities considered. (3) The case studies revealed that many small stream areas possess medium to high potential for camping, fishing, picnicking, trail system development and some forms of esthetic enjoyment. (4) Visitation estimates were judged to be only approximate due to lack of relevant data on similar existing recreation areas. Estimates of participation demand, acreage requirements and annual benefits were somewhat more reliable.
Suggestions for further research include: (1) Additional applications of the evaluation methodology to streams in other Kentucky urban areas and in states having climatic, topographic and socio-economic conditions different from Kentucky\u27s and (2) A feasibility study of the use of a psychometrics approach to determine personal preferences about outdoor recreation and the preservation of natural areas
Ariel - Volume 7 Number 2
Editors
Mark Dembert
Frank Chervanek
John Lammie
Jim Burke
Curt Cumming
Methods for Controlling Woody Invasian into CRP Fields in Tennessee
Woody cover is an important component of northern bobwhite (Colinus virginianus) habitat; however, some species such as red maple (Acer rubrum) and sweetgum (Liquidambar styraciflua) grow aggressively and may become dominant on unmanaged areas. Six treatments with controls were implemented in a completely randomized design on a Conservation Reserve Program (CRP) old-field planted to tall fescue (Lolium arundinarium) with extensive invasion by sweetgum, red maple, and other woody saplings to determine the most effective method for reducing coverage of woody plants. Treatments included dormant-season burning in March 2004, applications of triclopyr, imazapyr, and glyphosate in July 2004, mowing in August 2004, and growing-season burning in September 2004. Resulting vegetation structure and composition were measured in July 2005. Percentage woody cover was reduced by all treatments (13-50%) except mowing (65.8%, SE=7.0) compared to control (80.4%, SE=7.6). Imazapyr (13.3%, SE=2.6), growing-season burn (14.2%, SE=3.1), and triclopyr (15.8%, SE=3.5) were most effective at reducing woody cover. Percentage cover of desirable legumes (Chamaecrista spp., Desmodium spp., Lespedeza spp.) was greatest in growing-season burn (54.2%, SE=6.7), imazapyr (28.3%, SE=5.9), and dormant-season burn (24.5%, SE=5.2) treatments. Imazapyr increased coverage of blackberry (Rubus spp.), while triclopyr increased coverage of warm- and cool-season grasses. Our results suggest growing-season fire in September was best at reducing woody plants and enhancing habitat for northern bobwhites. Growing-season fire resulted in the greatest coverage of desirable legumes, reduced litter depth, and increased percent bare ground. If burning is not possible, applications of imazapyr or tryclopyr may be suitable alternatives
Leiomyosarcoma of the Inferior Turbinate
We report a case of leiomyosarcoma of the inferior nasal turbinate. The patient, a 68-year-old Caucasian male, presented with 4–6 weeks of epistaxis that was resistant to nasal packing and septal cautery. Upon inspection in the operating room, a small mass was excised from the inferior turbinate. High-power H&E-stained microscopy demonstrated bundles of malignant smooth muscle cells, and immunohistochemical stains were strongly positive for desmin, smooth muscle actin and vimentin, while negative for pankeratin EA1/EA3 and CaM 5.2, suggesting leiomyosarcoma as the diagnosis. Clear margins were obtained at a second surgery. At the time of this writing it is 8 months since his last surgery and he has remained symptom free
Effects of fiber, matrix, and interphase on carbon fiber composite compression strength
The major goal of this project was to obtain basic information on compression failure properties of carbon fiber composites. To do this, we investigated fiber effects, matrix effects, and fiber/matrix interface effects. Using each of nine fiber types, we prepared embedded single-fiber specimens, single-ply specimens, and full laminates. From the single-fiber specimens, in addition to the standard fragmentation test analysis, we were able to use the low crack density data to provide information about the distribution of fiber flaws. The single-ply specimens provided evidence of a correlation between the size of kink band zones and the quality of the interface. Results of the laminate compression experiments mostly agreed with the results from single-ply experiments, although the ultimate compression strengths of laminates were higher. Generally, these experiments showed a strong effect of interfacial properties. Matrix effects were examined using laminates subjected to precracking under mixed-mode loading conditions. A large effect of precracking conditions on the mode 1 toughness of the laminates was found. In order to control the properties of the fiber/matrix interface, we prepared composites of carbon fiber and polycarbonate and subjected these to annealing. The changes in interfacial properties directly correlated with changes in compression strength
A Preliminary Flight Investigation of the Effect of Snaking Oscillations on the Pilots' Opinions of the Flying Qualities of a Fighter Airplane
Northern Bobwhite Survival Related to Movement on a Reclaimed Surface Coal Mine
Reclaimed coal mines represent opportunity to provide large tracts of early succession habitat essential to northern bobwhite (Colinus virginianus) populations. However, little research has been conducted to explore the potential of reclaimed mine sites and examine bobwhite ecology on these unique areas. Reclaimed mines in Kentucky were planted to non-native species, such as sericea lespedeza (Lespedeza cuneata) and tall fescue (Festuca arundinacea), which do not provide suitable structure for northern bobwhite brood-rearing and movement. Fallow disking (in blocks and linear firebreaks) and planting food plots are part of current management efforts to improve food availability and habitat structure for broods. We trapped and radiomarked 266 northern bobwhites between April 2010 and September 2011 on Peabody Wildlife Management Area, a 3,330-ha reclaimed coal mine in western Kentucky, USA to investigate the effects of current management practices on movement and survival. We calculated seasonal daily movement as the Euclidean distance from a location on day 1 to day 2. Breeding season (1 Apr-30 Sep) movement averaged 128 m in 2010 and 147 m in 2011. Daily movement averaged 163 m during the 2010–2011 non-breeding (1 Oct-31 Mar) season. Multiple regression analysis indicated annual food plots, disk blocks, firebreaks, and roads did not explain variation within daily movement regardless of season (R2 0.04). Individual bird/covey, precipitation, hours between locations, and average temperature also poorly explained movement variation. We used Program MARK to model the effect of season, year, mean daily movement, mean distance to annual food plots, disk blocks, firebreaks, and roads on survival. The season (breeding/non-breeding) model explained 81% of the variation in survival, and the year model explained 13%, suggesting management was not driving survival. We do not believe disking should be discontinued, although it did not influence movement, as it can improve vegetation structure important to nest-site selection and broods
Fis Is Essential for Capsule Production in Pasteurella multocida and Regulates Expression of Other Important Virulence Factors
P. multocida is the causative agent of a wide range of diseases of animals, including fowl cholera in poultry and wild birds. Fowl cholera isolates of P. multocida generally express a capsular polysaccharide composed of hyaluronic acid. There have been reports of spontaneous capsule loss in P. multocida, but the mechanism by which this occurs has not been determined. In this study, we identified three independent strains that had spontaneously lost the ability to produce capsular polysaccharide. Quantitative RT-PCR showed that these strains had significantly reduced transcription of the capsule biosynthetic genes, but DNA sequence analysis identified no mutations within the capsule biosynthetic locus. However, whole-genome sequencing of paired capsulated and acapsular strains identified a single point mutation within the fis gene in the acapsular strain. Sequencing of fis from two independently derived spontaneous acapsular strains showed that each contained a mutation within fis. Complementation of these strains with an intact copy of fis, predicted to encode a transcriptional regulator, returned capsule expression to all strains. Therefore, expression of a functional Fis protein is essential for capsule expression in P. multocida. DNA microarray analysis of one of the spontaneous fis mutants identified approximately 30 genes as down-regulated in the mutant, including pfhB_2, which encodes a filamentous hemagglutinin, a known P. multocida virulence factor, and plpE, which encodes the cross protective surface antigen PlpE. Therefore these experiments define for the first time a mechanism for spontaneous capsule loss in P. multocida and identify Fis as a critical regulator of capsule expression. Furthermore, Fis is involved in the regulation of a range of other P. multocida genes including important virulence factors
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