999 resultados para HOLLOW FLANGE SECTION
Resumo:
Geobiota are defined by taxic assemblages (i.e., biota) and their defining abiotic breaks, which are mapped in cross-section to reveal past and future biotic boundaries. We term this conceptual approach Temporal Geobiotic Mapping (TGM) and offer it as a conceptual approach for biogeography. TGM is based on geological cross-sectioning, which creates maps based on the distribution of biota and known abiotic factors that drive their distribution, such as climate, topography, soil chemistry and underlying geology. However, the availability of abiotic data is limited for many areas. Unlike other approaches, TGM can be used when there is minimal data available. In order to demonstrate TGM, we use the well-known area in the Blue Mountains, New South Wales (NSW), south-eastern Australia and show how surface processes such as weathering and erosion affect the future distribution of a Moist Basalt Forest taxic assemblage. Biotic areas are best represented visually as maps, which can show transgressions and regressions of biota and abiota over time. Using such maps, a biogeographer can directly compare animal and plant distributions with features in the abiotic environment and may identify significant geographical barriers or pathways that explain biotic distributions.
Resumo:
The 82nd General Assembly of the Iowa legislature, in Section 26 of Senate File 2420, required the Iowa Department of Transportation (Iowa DOT) to conduct an analysis of TIME-21 funding. Specifically the legislation requires the following: “The department of transportation shall conduct an analysis of the additional revenues necessary to provide at least two hundred million dollars annually to the TIME-21 fund by FY 2011-2012. The analysis shall include but is not limited to the amount of excise tax levied on motor fuel and adjustments that might be made to various fees collected by the department in order to create an appropriate balance of taxes and fees paid by Iowa drivers and out-of-state drivers. The department shall submit a report to the governor and the general assembly on or before December 31, 2008, regarding its analysis.” As a starting point to this analysis, a reassessment of long-range needs and revenues (including the estimated $200 million most critical annual unmet needs) was made. This was done by assessing changing trends in roadway conditions, revenue and construction costs since the original Study of Iowa’s Current Road Use Tax Funds (RUTF) and Future Road Maintenance and Construction Needs was completed December 2006.
Resumo:
The 82nd General Assembly of the Iowa legislature, in Section 26 of Senate File 2420, required the Iowa Department of Transportation (Iowa DOT) to conduct an analysis of TIME-21 funding. Specifically the legislation requires the following: “The department of transportation shall conduct an analysis of the additional revenues necessary to provide at least two hundred million dollars annually to the TIME-21 fund by FY 2011-2012. The analysis shall include but is not limited to the amount of excise tax levied on motor fuel and adjustments that might be made to various fees collected by the department in order to create an appropriate balance of taxes and fees paid by Iowa drivers and out-of-state drivers. The department shall submit a report to the governor and the general assembly on or before December 31, 2008, regarding its analysis.” As a starting point to this analysis, a reassessment of long-range needs and revenues (including the estimated $200 million most critical annual unmet needs) was made. This was done by assessing changing trends in roadway conditions, revenue and construction costs since the original Study of Iowa’s Current Road Use Tax Funds (RUTF) and Future Road Maintenance and Construction Needs was completed December 2006.
Resumo:
Cobalt-labelled motoneuron dendrites of the frog spinal cord at the level of the second spinal nerve were photographed in the electron microscope from long series of ultrathin sections. Three-dimensional computer reconstructions of 120 dendrite segments were analysed. The samples were taken from two locations: proximal to cell body and distal, as defined in a transverse plane of the spinal cord. The dendrites showed highly irregular outlines with many 1-2 microns-long 'thorns' (on average 8.5 thorns per 100 microns 2 of dendritic area). Taken together, the reconstructed dendrite segments from the proximal sites had a total length of about 250 microns; those from the distal locations, 180 microns. On all segments together there were 699 synapses. Nine percent of the synapses were on thorns, and many more close to their base on the dendritic shaft. The synapses were classified in four groups. One third of the synapses were asymmetric with spherical vesicles; one half were symmetric with spherical vesicles; and one tenth were symmetric with flattened vesicles. A fourth, small class of asymmetric synapses had dense-core vesicles. The area of the active zones was large for the asymmetric synapses (median value 0.20 microns 2), and small for the symmetric ones (median value 0.10 microns 2), and the difference was significant. On average, the areas of the active zones of the synapses on thin dendrites were larger than those of synapses on large calibre dendrites. About every 4 microns 2 of dendritic area received one contact. There was a significant difference between the areas of the active zones of the synapses at the two locations. Moreover, the number per unit dendritic length was correlated with dendrite calibre. On average, the active zones covered more than 4% of the dendritic area; this value for thin dendrites was about twice as large as that of large calibre dendrites. We suggest that the larger active zones and the larger synaptic coverage of the thin dendrites compensate for the longer electrotonic distance of these synapses from the soma.
Resumo:
study of channel catfish in the Mississippi River to determine differences in year class abundance and causative factors
