Hydrokinetic canal measurements: inflow velocity, wake flow velocity, and turbulence

DOE Data Explorer

Gunawan, Budi

2014-06-11

The dataset consist of acoustic Doppler current profiler (ADCP) velocity measurements in the wake of a 3-meter diameter vertical-axis hydrokinetic turbine deployed in Roza Canal, Yakima, WA, USA. A normalized hub-centerline wake velocity profile and two cross-section velocity contours, 10 meters and 20 meters downstream of the turbine, are presented. Mean velocities and turbulence data, measured using acoustic Doppler velocimeter (ADV) at 50 meters upstream of the turbine, are also presented. Canal dimensions and hydraulic properties, and turbine-related information are also included.

Effects of water-control structures on hydrologic and water-quality characteristics in selected agricultural drainage canals in eastern North Carolina

USGS Publications Warehouse

Treece, M.W.; Jaynes, M.L.

1994-01-01

November of water into and out of tidally affected canals in eastern North Carolina was documented before and after the installation of water-control structures. Water levels in five of the canals downstream from the water-control structures were controlled primarily by water-level fluctuations in estuarine receiving waters. Water-control structures also altered upstream water levels in all canals. Water levels were lowered upstream from tide gates, but increased upstream from flashboard risers. Both types of water-control structures attenuated the release of runoff following rainfall events, but in slightly different ways. Tide gates appeared to reduce peak discharge rates associated with rainfall, and flashboard risers lengthened the duration of runoff release. Tide gates had no apparent effect on pH, dissolved oxygen, suspended-sediment, or total phosphorus concentrations downstream from the structures. Specific conductance measured from composite samples collected with automatic samples increased downstream of tide gates after installation. Median concentrations of nitrite plus nitrate nitrogen were near the minimum detection level throughout the study; however, the number of observations of concentrations exceeding 0.1 milligram per liter dropped significantly after tide gates were installed. Following tide-gate installation, instantaneous loadings of nitrite plus nitrate nitrogen were significantly reduced at one test site, but this reduction was not observed at the other test site. Loadings of other nutrient species and suspended sediment did not change at the tide-gate test sites after tide-gate installation. Specific conductance was lower in the Beaufort County canals than in the Hyde County canals. Although there was a slight increase in median values at the flashboard-riser sites, the mean and maximum values declined substantially downstream from the risers following installation. This decline of specific conductance in the canals occurred despite a large increase of specific conductance in the tidal creek. Flashboard risers had no significant effect on concentrations of dissolved oxygen, suspended sediment, total ammonia plus organic nitrogen, or phosphorus. Maximum concentrations of ammonia nitrogen were smaller at both test sites after riser installation. In addition, concentrations of nitrite plus nitrate nitrogen exceeding 1.0 milligram per liter rarely occurred at the flashboard-riser test sites following installation of the risers. Median loadings of nitrite plus nitrate nitrogen and total nitrogen decreased at one riser test site following flashboard-riser installation. Tide gates and flashboard risers were associated with reductions in concentrations and export of nitrite plus nitrate nitrogen; however, these changes should be interpreted cautiously because reductions were not observed consistently at every site. The hydrology and baseline water-quality characteristics of the two study areas differ, making comparisons of the effectiveness of the two types of water-control structures difficult to interpret. The effects of water-control structures on the hydrology of the drainage canals are more meaningful than the changes in water quality. Tide gates and flashboard risers altered the hydrologic characteristics of the drainage canals and created an environment favorable for nutrient loss or transformation. Both structures retained agricultural drainage upstream, which increased potential storage for infiltration and reduced the potential for surface runoff, sediment, and nutrient transport, and higher peak outflow rates.

VIEW OF MORTARED ROCK AND CONCRETE INLET TO COUCH LATERAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF MORTARED ROCK AND CONCRETE INLET TO COUCH LATERAL CANAL, UPSTREAM OF COLLINS ROAD. LOOKING NORTH/NORTHEAST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

Evaluation of Streamflow Losses Along the Gunnison River from Whitewater Downstream to the Redlands Canal Diversion Dam, near Grand Junction, Colorado, Water Years 1995-2003

USGS Publications Warehouse

Kuhn, Gerhard; Williams, Cory A.

2004-01-01

In 2003, the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, Upper Colorado River Endangered Fish Recovery Program, Colorado River Water Conservation District, Colorado Division of Water Resources, and Bureau of Reclamation, initiated a study to characterize streamflow losses along a reach of the Gunnison River from the town of Whitewater downstream to the Redlands Canal diversion dam. This describes the methods and results of the study that include: (1) a detailed mass-balance analysis of historical discharge records that were available for the three streamflow-gaging stations along the study reach; and (2) two sets of discharge measurements that were made at the three stations and at four additional locations. Data for these existing streamflow-gaging stations were compiled and analyzed: (1) Gunnison River near Grand Junction (Whitewater station); (2) Gunnison River below Redlands Canal diversion dam (below-Redlands-dam station); and (3) Redlands Canal near Grand Junction (Redlands-Canal station). Data for water years 1995-2003 were used for the mass-balance analysis. Four intermediate sites (M1, M2, M3, and M4) were selected for discharge measurements in addition to the existing stations. The study reach is the approximate 12-mile reach of the Gunnison River from the Whitewater station downstream to the Redlands Canal diversion dam, which is about 3 miles upstream from the confluence with the Colorado River. For the mass-balance analysis, differences between the sum of the annual cumulative daily mean discharge at the two downstream stations and the annual cumulative daily mean discharges at the upstream station ranged from about -8,700 to -69,800 acre-feet (about -.8 to -1.1 percent), indicating that the downstream discharges generally were less than the upstream discharges. Moving 3-day daily mean discharge averages also were computed for each of the three stations to smooth out some of the abrupt differences between the downstream and upstream daily mean discharges. During water years 1995-2002, differences between the downstream and upstream moving 3-day daily mean discharges ranged from about -200 to +100 cubic feet per second (ft3/s) during one-half of each year, but the differences had absolute values as large as about 500 to 1,000 ft3/s during the other one-half of the year. The differences as a percentage of the upstream discharge ranged from 0 to -10 percent within the interquartile range and were as small or large as about -60 to +50. Two sets of discharge measurements were obtained during water year 2003. For measurement set 1 (February 5-6), discharge was measured 5-8 times over a 24-hour period at sites M1-M4, where measured discharges ranged from 527 to 608 ft3/s. Discharge was measured once each day at the Whitewater and below-Redlands-dam stations to verify discharge rating shifts; the Redlands Canal was not in operation at this time, so measurements were not needed at the Redlands-Canal station. Recorded 15-minute (unit) discharges ranged from about 575 to 615 ft3/s at the Whitewater station and from about 560 to 600 ft3/s at the below-Redlands-dam station during the February 5-6 period. Because of the inherent error in discharge measurements (5 percent for measurements rated good), and because the mean discharge at the below-Redlands-dam station, about 580 ft3/s, was only about 2.5 percent smaller than the mean discharge at the Whitewater station, about 595 ft3/s, it is concluded that there was no measurable streamflow loss along the study reach during measurement set 1. For measurement set 2 (May 14-15), discharge in the Gunnison River was about 2,000 ft3/s and increasing because of high-elevation snowmelt. Five discharge measurements were made at site M2 and discharge ranged from 1,668 to 2,117 ft3/s. Measured discharges at the gaging stations were 2,730 ft3/s at the Whitewater station, 1,268 ft3/s at the below-Redlands-dam station, and 819 ft3/s at the

Frequency of second mesiobuccal canal in permanent maxillary first molars using the operating microscope and selective dentin removal: A clinical study.

PubMed

Das, Suroopa; Warhadpande, Manjusha M; Redij, Saurabh A; Jibhkate, N G; Sabir, Husain

2015-01-01

The aim of this study was to investigate whether the combination of operating microscope and selective dentin removal increased the frequency of second mesiobuccal (MB2) canal detection in permanent maxillary first molar teeth. One hundred fifty permanent maxillary first molars indicated for root canal treatment were randomly selected from patients belonging to the age group of 18-45 years irrespective of gender. After access cavity preparation and location of main canals, the MB2 canal orifice was sought in all teeth with an endodontic explorer under direct vision (Stage I), then under magnification with the aid of operating microscope (Stage II) and finally with the combined use of operating microscope and selective dentin removal (Stage III). MB2 canals were detected in 36%, 54% and 72% of the teeth in Stages I-III, respectively. This study demonstrated that dental operating microscope when used along with adjunctive aids such as selective dentin removal/troughing and good clinical knowledge will increase the ability of dental clinician to locate MB2 canals.

Staged electrostatic precipitator

DOEpatents

Miller, Stanley J.; Almlie, Jay C.; Zhuang, Ye

2016-03-01

A device includes a chamber having an air inlet and an air outlet. The device includes a plurality of stages including at least a first stage adjacent a second stage. The plurality of stages are disposed in the chamber and each stage has a plurality of discharge electrodes disposed in an interior region and is bounded by an upstream baffle on an end proximate the air inlet and bounded by a downstream baffle on an end proximate the air outlet. Each stage has at least one sidewall between the upstream baffle and the downstream baffle. The sidewall is configured as a collection electrode and has a plurality of apertures disposed along a length between the upstream baffle and the downstream baffle. The upstream baffle of the first stage is positioned in staggered alignment relative to the upstream baffle of the second stage and the downstream baffle of the first stage are positioned in staggered alignment relative to the downstream baffle of the second stage.

Human factors and tidal influences on water quality of an urban river in Can Tho, a major city of the Mekong Delta, Vietnam.

PubMed

Ozaki, Hirokazu; Co, Thi Kinh; Le, Anh Kha; Pham, Viet Nu; Nguyen, Van Be; Tarao, Mitsunori; Nguyen, Huu Chiem; Le, Viet Dung; Nguyen, Hieu Trung; Sagehashi, Masaki; Ninomiya-Lim, Sachi; Gomi, Takashi; Hosomi, Masaaki; Takada, Hideshige

2014-02-01

In this study, we focused on water quality in an urban canal and the Mekong River in the city of Can Tho, a central municipality of the Mekong Delta region, southern Vietnam. Water temperature, pH, electrical conductivity, BOD5, CODCr, Na(+), Cl(-), NH4 (+)-N, SO4 (2-)-S, NO3 (-)-N, and NO2 (-)-N for both canal and river, and tide level of the urban canal, were monitored once per month from May 2010 to April 2012. The urban canal is subject to severe anthropogenic contamination, owing to poor sewage treatment. In general, water quality in the canal exhibited strong tidal variation, poorer at lower tides and better at higher tides. Some anomalies were observed, with degraded water quality under some high-tide conditions. These were associated with flow from the upstream residential area. Therefore, it was concluded that water quality in the urban canal changed with a balance between dilution effects and extent of contaminant supply, both driven by tidal fluctuations in the Mekong River.

29. VIEW OF THE DIVERSION STRUCTURE PICTURED IN CO43A28 FROM ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

29. VIEW OF THE DIVERSION STRUCTURE PICTURED IN CO-43-A-28 FROM THE CHANNEL OF THE LATERAL, SHOWING THE UPSTREAM FACE OF THE STRUCTURE. - Highline Canal, Sand Creek Lateral, Beginning at intersection of Peoria Street & Highline Canal in Arapahoe County (City of Aurora), Sand Creek lateral Extends 15 miles Northerly through Araphoe County, City & County of Denver, & Adams County to its end point, approximately 1/4 mile Southest of intersectioin of D Street & Ninth Avenue in Adams County (Rocky Mountain Arsenal, Commerce City Vicinity), Commerce City, Adams County, CO

Capacitively coupled and direct-current resistivity surveys of selected reaches of Cozad, Thirty-Mile, Orchard-Alfalfa, Kearney, and Outlet Canals in Nebraska, 2012-13

USGS Publications Warehouse

Hobza, Christopher M.; Burton, Bethany L.; Lucius, Jeffrey E.; Tompkins, Ryan E.

2014-01-01

Understanding the spatial characteristics of leakage from canals is critical to effectively managing and utilizing water resources for irrigation and hydroelectric purposes. Canal leakage in some parts of Nebraska is the primary source of water for groundwater recharge and helps maintain the base flow of streams. Because surface-water supplies depend on the streamflow of the Platte River and the available water stored in upstream reservoirs, water managers seek to minimize conveyance losses, which can include canal leakage. The U.S. Geological Survey, in cooperation with the Central Platte Natural Resources District and Nebraska Public Power District, used capacitively coupled (CC) and direct-current (DC) resistivity techniques for continuous resistivity profiling to map near-surface lithologies near and underlying the Cozad, Thirty-Mile, Orchard-Alfalfa, Kearney, and Outlet Canals. Approximately 84 kilometers (km) of CC-resistivity data were collected along the five canals. The CC-resistivity data were compared with results from continuous sediment cores and electrical conductivity logs. Generally, the highest resistivities were recorded at the upstream reaches of the Cozad, Thirty-Mile, and Orchard-Alfalfa canals where flood-plain deposits of silt and clay mantle coarser channel deposits of sand and gravel. The finer grained deposits gradually thicken with increasing distance away from the Platte River. Consequently, for many surveyed reaches the thickness of fine-grained deposits exceeded the 8-meter depth of investigation. A detailed geophysical investigation along a 5-km reach of the Outlet Canal southwest of North Platte, Nebraska, used CC and DC resistivity to examine the condition of a compacted-core bank structure and characterized other potential controls on areas of focused seepage. CC-resistivity data, collected along the 5-km study reach, were compared with continuous sediment cores and DC-resistivity data collected near a selected seep near Outlet Canal mile post 15.55 along 5 separate profiles. DC-resistivity results were compared to a schematic cross section of the Outlet Canal north embankment that include the original surfaces and modifications to the compacted-core bank structure. Along the canal road south line, there is a transition from high resistivity at land surface to much lower resistivity near the estimated depth of the northern slope of the original compacted-core bank; however, the surveyed elevation of the water surface in the canal also is at this elevation. Along the canal road north line, there is a transition from high resistivity near land surface to lower resistivity at depth. Although the transition is rapid near the estimated depth of the first-modified bank slope, it also is coincident with the groundwater level measured in piezometer PZ-4. Currently (2013), it is unknown if the indicated changes in resistivity at these elevations was the effect of saturation of the underlying sediments or caused by the compacted-core bank.

Phase I of the Kissimmee River restoration project, Florida, USA: impacts of construction on water quality.

PubMed

Colangelo, David J; Jones, Bradley L

2005-03-01

Phase I of the Kissimmee River restoration project included backfilling of 12 km of canal and restoring flow through 24 km of continuous river channel. We quantified the effects of construction activities on four water quality parameters (turbidity, total phosphorus flow-weighted concentration, total phosphorus load and dissolved oxygen concentration). Data were collected at stations upstream and downstream of the construction and at four stations within the construction zone to determine if canal backfilling and construction of 2.4 km of new river channel would negatively impact local and downstream water quality. Turbidity levels at the downstream station were elevated for approximately 2 weeks during the one and a half year construction period, but never exceeded the Florida Department of Environmental Protection construction permit criteria. Turbidity levels at stations within the construction zone were high at certain times. Flow-weighted concentration of total phosphorus at the downstream station was slightly higher than the upstream station during construction, but low discharge limited downstream transport of phosphorus. Total phosphorus loads at the upstream and downstream stations were similar and loading to Lake Okeechobee was not significantly affected by construction. Mean water column dissolved oxygen concentrations at all sampling stations were similar during construction.

75 FR 77762 - Final Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-14

... Flooding source(s) elevation in feet above Communities affected ground [caret] Elevation in meters (MSL... South Monroe Village. Lane. Just upstream of High +5,491 Line Canal. Box Elder Creek Approximately 1,400...,773 downstream of East Arapahoe Road. Goldsmith Gulch West Tributary......... Approximately 400 feet...

2. View of Potomac River at Great Falls looking upstream ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. View of Potomac River at Great Falls looking upstream from Observation Tower. The majestic character of this wild and untrammeled spot is vividly shown. Scanty flow is evidenced by light colored normal water line markings on rock formation. Washington Agueduct Dam is shown in upper portion. Maryland on right and Virginia on left. Natives quoted as saying the water was as low or lower than during the drought conditions of 1930. Mr. Horyduzak, Photographer, 1943. - Potowmack Company: Great Falls Canal & Locks, Great Falls, Fairfax County, VA

Development of the otolith organs and semicircular canals in the Japanese red-bellied newt, Cynops pyrrhogaster

NASA Technical Reports Server (NTRS)

Wiederhold, M. L.; Yamashita, M.; Larsen, K. A.; Batten, J. S.; Koike, H.; Asashima, M.

1995-01-01

The sequence in which the otoliths and semicircular canals and their associated sensory epithelia appear and develop in the newt are described. Three-dimensional reconstruction of serial sections through the otic vesicle of newt embryos from stages 31 through 58 demonstrate the first appearance, relative position and growth of the otoliths. A single otolith is first seen in stage 33 embryos (approximately 9 days old); this splits into separate utricular and saccular otoliths at stage 40 (13 days). The lateral semicircular canal is the first to appear, at stage 41 (14 days). The anterior and posterior canals appear approximately one week later and the vestibular apparatus is essentially fully formed at stage 58 (approximately 5 weeks). The data reported here will serve as ground-based controls for fertilized newt eggs flown on the International Microgravity Laboratory-2 Space Shuttle flight, to investigate the influence of microgravity on the development of the gravity-sensing organs.

20. VIEW LOOKING SOUTHEAST FROM THE SHORE OF THE POTOMAC ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. VIEW LOOKING SOUTHEAST FROM THE SHORE OF THE POTOMAC RIVER AT THE UPSTREAM SIDE OF THE CONTROL GATES AND LOCK FOR THE ARMORY CANAL. - Potomac Power Plant, On West Virginia Shore of Potomac River, about 1 mile upriver from confluence with Shenandoah River, Harpers Ferry, Jefferson County, WV

Floods at Mount Clemens, Michigan

USGS Publications Warehouse

Wiitala, S.W.; Ash, Arlington D.

1962-01-01

The approximate areas inundated during the flood of April 5-6, 1947, by Clinton River, North Branch and Middle Branch of Clinton River, and Harrington Drain, in Clinton Township, Macomb County, Mich., are shown on a topographic map base to record the flood hazard in graphical form. The flood of April 1947 is the highest known since 1934 and probably since 1902. Greater floods are possible, but no attempt was made to define their probable overflow limits.The Clinton River Cut-Off Canal, a flood-relief channel which diverts flow directly into Lake St. Clair from a point about 1500 feet downstream from Gratiot Avenue (about 9 miles upstream from the mouth) has been in operation since October 1951. The approximate limits of overflow that would results from a flood equivalent in discharge to that of April 1947, and occurring with the Cut-Off Canal in operation, are also shown. Although the Cut-Off Canal may reduce the frequency and depth of flooding it will not necessarily eliminate future flooding in the area. Improvements and additions to the drainage systems in the basin, expanding urbanization, new highways, and other cultural changes may influence the inundation pattern of future floods.The preparation of this flood inundation map was financed through a cooperative agreement between Clinton Township, Macomb County, Mich., and the U.S. Geological Survey.Backwater curves used to define the profile for a hypothetical flood on the Clinton River downstream from Moravian Drive, equivalent in discharge to the 1947 flood, but occurring with the present Cut-Off Canal in operation; flood stage established at the gaging station on Clinton River at Mount Clemens; and supplementary floodmark elevations were furnished by the Corps of Engineers.Bench-mark elevations and field survey data, used in the analysis of floods on Harrington Drain, were furnished by the Macomb County Drain Commission.

Method of and apparatus for testing the integrity of filters

DOEpatents

Herman, R.L.

1985-05-07

A method of and apparatus are disclosed for testing the integrity of individual filters or filter stages of a multistage filtering system including a diffuser permanently mounted upstream and/or downstream of the filter stage to be tested for generating pressure differentials to create sufficient turbulence for uniformly dispersing trace agent particles within the airstream upstream and downstream of such filter stage. Samples of the particle concentration are taken upstream and downstream of the filter stage for comparison to determine the extent of particle leakage past the filter stage. 5 figs.

Method of and apparatus for testing the integrity of filters

DOEpatents

Herman, Raymond L [Richland, WA

1985-01-01

A method of and apparatus for testing the integrity of individual filters or filter stages of a multistage filtering system including a diffuser permanently mounted upstream and/or downstream of the filter stage to be tested for generating pressure differentials to create sufficient turbulence for uniformly dispersing trace agent particles within the airstream upstream and downstream of such filter stage. Samples of the particle concentration are taken upstream and downstream of the filter stage for comparison to determine the extent of particle leakage past the filter stage.

Methods of and apparatus for testing the integrity of filters

DOEpatents

Herman, R.L.

1984-01-01

A method of and apparatus for testing the integrity of individual filters or filter stages of a multistage filtering system including a diffuser permanently mounted upstream and/or downstream of the filter stage to be tested for generating pressure differentials to create sufficient turbulence for uniformly dispersing trace agent particles within the airstram upstream and downstream of such filter stage. Samples of the particel concentration are taken upstream and downstream of the filter stage for comparison to determine the extent of particle leakage past the filter stage.

Geochemistry of the suspended sediment in the estuaries of the Mandovi and Zuari rivers, central west coast of India.

PubMed

Kessarkar, Pratima M; Shynu, R; Rao, V Purnachandra; Chong, Feng; Narvekar, Tanuja; Zhang, Jing

2013-05-01

The geochemistry of the suspended particulate matter (SPM) collected during the monsoon was determined to identify the sources of SPM and to understand the physicochemical processes in the Mandovi and Zuari river estuaries. The concentrations of SPM decrease seaward in both estuaries, but are relatively high at bay stations. Kaolinite is the most dominant clay mineral in the upstream of both rivers. Smectite increases seaward in both estuaries and is abundant in the bay. Upstream stations of Mandovi, where ore deposits are stored on the shore, exhibit high Fe, Mn, total rare earth elements (∑REE), and middle REE- and heavy REE-enriched patterns. Channel stations of both estuaries exhibit middle REE- and light REE-enriched patterns, which gradually changed seaward to middle REE- and heavy REE-enriched patterns. Canal stations exhibit the highest concentrations of major and trace metals. High metal/Al ratios occur at stations in the upstream of Zuari and at the confluence of canals in the Mandovi estuary. Enrichment factors of metals indicate that Mn is significantly polluted while other metals are moderately polluted. The δ(13)C and δ(15)N of organic matter indicate that the terrigenous organic matter at the upstream is diluted seaward by marine organic matter. Organic matter at bay stations is largely marine and altered-type. The compositions of SPM are controlled by the particulates from ore dust, the geology of the drainage basins, and the physicochemical processes in the estuaries. Particulates resuspended from the bay are dominated by ore dust, which are advected into the channels of both estuaries during the lull periods of the monsoon.

Effects of lowering interior canal stages on salt-water intrusion into the shallow aquifer in Southeast Palm Beach County, Florida

USGS Publications Warehouse

Land, Larry F.

1975-01-01

Land in southeast Palm Beach County is undergoing a large-scale change in use, from agricultural to residential. To accommodate residential use, a proposal has been made by developers to the Board of the Lake Worth Drainage District to lower the canal stages in the interior part of the area undergoing change. This report documents one of the possible effects of such lowering. Of particular interest to the Board was whether the lower canal stages would cause an increase in salt-water intrusion into the shallow aquifer along the coast. The two main tools used in the investigation were a digital model for aquifer evaluation and an analytical technique for predicting the movement of the salt-water front in response to a change of ground-water flow into the ocean. The method of investigation consisted of developing a digital ground-water flow model for three east-west test strips. They pass through the northern half of municipal well fields in Lake Worth, Delray Beach, and Boca Raton. The strips were first modeled with no change in interior canal stages. Then they were modeled with a change in canal stages of 2 to 4 feet (0.6 to 1.6 metres). Also, two land development schemes were tested. One was for a continuation of the present level of land development, simulated by continuing the present pumpage rates. The second scheme was for land development to continue until the maximum allowable densities were reached, simulated by increasing the pumping rates. The results of the test runs for an east-west strip through Lake Worth show that lowering part of the interior canal water levels 3 feet (1.0 metre), as done in 1961, does not affect the aquifer head or salt-water intrusion along the coastal area of Lake Worth. As a result, no effect in the coastal area would be expected as a result of canal stage lowering in other, interior parts of the study area. Results from the other test runs show that lowering interior canal water levels by as much as 4 feet (1.2 metres) would result in some salt-water intrusion for either land development scheme. Salt-water intrusion is dependent on the location, and amount of water withdrawn, from well fields.

The impact of conjunctive use of canal and tube well water in Lagar irrigated area, Pakistan

NASA Astrophysics Data System (ADS)

Kazmi, Syed Iftikhar; Ertsen, Maurits W.; Asi, Muhammad Rafique

Introduction of the large gravity irrigation system in the Indus Basin in the late 19th century without a drainage system resulted in a rising water table, which resulted in water logging and salinity problems over large areas. In order to cope with the salinity and water logging problem, the Pakistan government initiated installation of 10,000 tube wells in different areas. This not only resulted in the lowering of water table, but also supplemented irrigation. Resulting benefits from the irrigation opportunities motivated framers to install private tube wells. The Punjab area meets 40% of its irrigation needs from groundwater abstraction. Today, farmers apply both surface water flows and groundwater from tube wells, creating a pattern of private and public water control. Sustainable use of groundwater needs proper quantification of the resource and information on processes involved in its recharge and discharge. The field work in the Lagar irrigated area, discussed in this paper, show that within the general picture of conjunctive use of canal water and groundwater, there is a clear spatial pattern between upstream and downstream areas, with upstream areas depending much less on groundwater than downstream areas. The irrigation context in the study area proves to be highly complex, with water users having differential access to canal and tube well water, resulting in different responses of farmers with their irrigation strategies, which in turn affect the salinity and water balances on the fields.

Photographic copy of photograph, photographer unknown, 18 February 1908 (original ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photographic copy of photograph, photographer unknown, 18 February 1908 (original print located at U.S. Bureau of Reclamation Upper Columbia Area Office, Yakima, Washington). "LAKE KACHESS CRIB DAM. TAKEN FROM UPSTREAM SIDE. 4 FEET OF SNOW" - Kachess Dam, 1904 Cascade Canal Company Crib Dam, Kachess River, 1.5 miles north of Interstate 90, Easton, Kittitas County, WA

Production of otoconia in the endolymphatic sac in the Japanese red-bellied newt, Cynops pyrrhogaster: light and transmission electron microscopic study

NASA Technical Reports Server (NTRS)

Gao, W.; Wiederhold, M. L.; Hejl, R.

1998-01-01

The formation of otoconia in the endolymphatic sac (ES) of the larval newt, Cynops pyrrhogaster, has been studied by light and transmission electron microscopy. Some of the epithelial cells of the ES contain an abundance of swollen vesicles, Golgi complexes, rough endoplasmic reticula and ribosomes at the late larval stages 50 and 51, approximately 26-30 days after eggs are laid. Five days later, at stage 52, crystals are present in the vacuoles between the epithelial cells. Serial sections indicate that these vacuoles actually form small canals which lie in the wall and join the lumen of the ES. Reconstruction of the ES shows that several canals are contained in the ES wall. At stage 56, about 72 days after eggs are laid, a large number of otoconia are present in the ES lumen, while the otoconia disappear from the canals. It appears that the otoconia are first produced in the canals and then released to the lumen. Some epithelial cells of the ES are thought to expel the organic and inorganic material to the canals to form the otoconia in situ. The process of formation of the otoconia in the ES is discussed.

Quantitative evaluation of root canal surface roughness after filing with adaptive reciprocating and continuous rotary instruments.

PubMed

Sakhaei Manesh, Vahid; Giacomin, Paul; Stoll, Richard

2017-06-01

Obtaining clean and smooth root canal walls is the ideal clinical outcome of the cleaning and shaping stage in root canal treatment. This study compares the surface roughness of root canal surfaces instrumented with a NiTi filing system with either adaptive reciprocating (AR) or continuous rotation (CR). Root canal cleaning and shaping was carried out on the mesial canals of 24 extracted first molars roots with either AR or CR. Roots were split in half and the surface roughness of their canals was evaluated in 12 three dimensional roughness reconstructions using a scanning electron microscope. Rz (nm) values were calculated in three areas of each reconstruction and analyzed (α = 0.05). Mann-Whitney tests showed that surface roughness was significantly higher overall in the AR group (Rz = 967 ± 250 nm) compared with the CR group (Rz = 739 ± 239 nm; p = 0.044). The roughness values generally increased from apical towards the coronal third in both groups. A less aggressive finishing file or a continuous rotary system to end the cleaning and shaping stage may be beneficial to reduce roughness of the root canal surface. © 2017 Wiley Periodicals, Inc.

Genus Distichopora (Cnidaria, Hydrozoa): from primary cyclosystem to adult pore organisation

NASA Astrophysics Data System (ADS)

Puce, S.; Pica, D.; Brun, F.; Mancini, L.; Bavestrello, G.

2012-09-01

This investigation provides the first detailed description of the growth stages of two Distichopora species showing the formation of a primary cyclosystem and explaining the growth process leading from primary cyclosystem to adult pore organisation. The earliest observed stage is an oval calcareous disc from which, at a later stage, a primary cyclosystem raises up. Then, the addition of new gastropores and dactylopores leads to the pore rows typical of the genus. Using X-ray computed microtomography, we are able to visualise the dense canal network that permeates the coenosteum and envelops the gastropores and the dactylopores in all the observed growth stages. In both species, the thin canals surrounding the gastropores are responsible for the formation of the new gastropores that originate between the old ones, while the thin canals placed on the external side of the dactylopore rows produce the new dactylopores.

33 CFR 207.680 - Willamette River, Oreg.; use, administration, and navigation of canal and locks at Willamette...

Code of Federal Regulations, 2011 CFR

2011-07-01

... and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION... through the locks. The controlling water depth over the intermediate miter sills throughout the locks is 6.5 feet. However, the depth on the sill of the upstream gate at low water is 7.5 feet and over the...

Identification of dissolved organic matter in raw water supply from reservoirs and canals as precursors to trihalomethanes formation.

PubMed

Musikavong, Charongpun; Wattanachira, Suraphong

2013-01-01

The characteristic and quantity of dissolved organic matter (DOM) as trihalomethanes precursors in water from the U-Tapao Basin, Songkhla, Thailand was investigated. The sources of water in the basin consisted of two reservoirs and the U-Tapao canal. The canal receives water discharge from reservoirs, treated and untreated wastewater from agricultural processes, communities and industries. Water downstream of the canal is utilized as a raw water supply. Water samples were collected from two reservoirs, upstream and midstream of the canal, and the raw water supply in the rainy season and summer. The DOM level in the canal water was higher than that of the reservoir water. The highest trihalomethane formation potential (THMFP) was formed in the raw water supply. Fourier-transform infrared peaks of the humic acid were detected in the reservoir and canal waters. Aliphatic hydrocarbon and organic nitrogen were the major chemical classes in the reservoir and canal water characterized by a pyrolysis gas chromatography mass spectrometer. The optimal condition of the poly aluminum chloride (PACl) coagulation was obtained at a dosage of 40 mg/L at pH 7. This condition could reduce the average UV-254 to 57%, DOC to 64%, and THMFP to 42%. In the coagulated water, peaks of O-H groups or H-bonded NH, C˭O of cyclic and acyclic compounds, ketones and quinines, aromatic C˭C, C-O of alcohols, ethers, and carbohydrates, deformation of COOH, and carboxylic acid salts were detected. The aliphatic hydrocarbon, organic nitrogen and aldehydes and ketones were the major chemical classes. These DOM could be considered as the prominent DOM for the water supply plant that utilized PACl as a coagulant.

Predicting the Effects of Man-Made Fishing Canals on Floodplain Inundation - A Modelling Study

NASA Astrophysics Data System (ADS)

Shastry, A. R.; Durand, M. T.; Neal, J. C.; Fernandez, A.; Hamilton, I.; Kari, S.; Laborde, S.; Mark, B. G.; Arabi, M.; Moritz, M.; Phang, S. C.

2016-12-01

The Logone floodplain in northern Cameroon is an excellent example of coupled human-natural systems because of strong couplings between the social, ecological and hydrologic systems. Overbank flow from the Logone River in September and October is essential for agriculture and fishing livelihoods. Fishers dig canals to catch fish during the flood's recession to the river in November and December by installing nets at the intersection of canals and the river. Fishing canals connect the river to natural depressions in the terrain and may serve as a man-made extension of the river drainage network. In the last four decades, there has been an exponential increase in the number of canals which may affect flood hydraulics and the fishery. The goal of this study is to characterize the relationship between the fishing canals and flood dynamics in the Logone floodplain, specifically, parameters of flooding and recession timings and the duration of inundation. To do so, we model the Bara region ( 30 km2) of the floodplain using LISFLOOD-FP, a two-dimensional hydrodynamic model with sub-grid parameterizations of canals. We use a simplified version of the hydraulic system at a grid-cell size of 30-m, using synthetic topography, parameterized fishing canals, and representing fishnets as a combination of weir and mesh screens. The inflow at Bara is obtained from a separate, lower resolution (1-km grid-cell) model forced by daily discharge records obtained from Katoa, located 25-km upstream of Bara. Preliminary results show more canals lead to early recession of flood and a shorter duration of flood inundation. A shorter duration of flood inundation reduces the period of fish growth and will affect fisher catch returns. Understanding the couplings within the system is important for predicting long-term dynamics and the impact of building more fishing canals.

The failures of root canal preparation with hand ProTaper.

PubMed

Bătăiosu, Marilena; Diaconu, Oana; Moraru, Iren; Dăguci, C; Tuculină, Mihaela; Dăguci, Luminiţa; Gheorghiţă, Lelia

2012-07-01

The failures of root canal preparation are due to some anatomical deviation (canal in "C" or "S") and some technique errors. The technique errors are usually present in canal root cleansing and shaping stage and are the result of endodontic treatment objectives deviation. Our study was made on technique errors while preparing the canal roots with hand ProTaper. Our study was made "in vitro" on 84 extracted teeth (molars, premolars, incisors and canines). The canal root of these teeth were cleansed and shaped with hand ProTaper by crown-down technique and canal irrigation with NaOCl(2,5%). The dental preparation control was made by X-ray. During canal root preparation some failures were observed like: canal root overinstrumentation, zipping and stripping phenomenon, discarded and/or fractured instruments. Hand ProTaper represents a revolutionary progress of endodontic treatment, but a deviation from accepted rules of canal root instrumentation can lead to failures of endodontic treatment.

Analysis of chemical contamination within a canal in a Mexican border colonia.

PubMed

Owens, Janel E; Niemeyer, Emily D

2006-04-01

This study examines urban pollution within Derechos Humanos, a colonia popular in Matamoros, Tamaulipas, Mexico. General water quality indicators (coliform bacteria, total dissolved solids, ecologically relevant cations and anions), heavy metals (copper, lead, nickel, zinc, iron and cadmium), and volatile organic compounds (benzene, toluene, ethylbenzene, styrene, and dichlorobenzene and xylene isomers) were quantified within a wastewater canal running adjacent to the community. Water samples were collected at multiple sites along the banks of the canal and evidence of anthropogenic emissions existed at each sampling location. Sample site 2, approximately 10 m upstream of the colonia, contained both the widest range of hazardous pollutants and the greatest number exceeding US Environmental Protection Agency surface water standards. At each sampling location, high concentrations of total coliform (> 10(4) colonies/100 mL sample), lead (ranging from 0.05 to 0.40 mg/L), nickel (levels from 0.21 to 1.45 mg/L), and benzene (up to 9.80 mg/L) were noted.

Effects of tow transit on the efficacy of the Chicago Sanitary and Ship Canal Electric Dispersal Barrier System

USGS Publications Warehouse

Davis, Jeremiah J.; LeRoy, Jessica Z.; Shanks, Matthew R.; Jackson, Patrick Ryan; Engel, Frank; Murphy, Elizabeth; Baxter, Carey L.; McInerney, Michael K.; Barkowski, Nicholas A.

2017-01-01

In 2016, the U.S. Fish and Wildlife Service, U.S. Geological Survey, and U.S. Army Corps of Engineers undertook a field study in the Chicago Sanitary and Ship Canal near Romeoville, Illinois to determine the influence of tow transit on the efficacy of the Electric Dispersal Barrier System (EDBS) in preventing the passage of juvenile fish (total length < 100 millimeters (mm)). Dual-frequency identification sonar data showed that large schools of juvenile fish (mean school size of 120 fish; n = 19) moved upstream and crossed the electric field of an array in the EDBS concurrent with downstream-bound (downbound) loaded tows in 89.5% of trials. Smaller schools of juvenile fish (mean school size of 98 fish; n = 15) moved downstream and crossed the electric field of an array in the EDBS concurrent with upstream-bound (upbound) loaded tows in 73.3% of trials. Observed fish passages through the EDBS were always opposite to the direction of tow movement, and not associated with propeller wash. These schools were not observed to breach the EDBS in the absence of a tow and showed no signs of incapacitation in the barrier during tow passage. Loaded tows transiting the EDBS create a return current of water flowing between the tow and the canal wall that typically travels opposite the direction of tow movement, and cause a decrease in the voltage gradient of the barrier of up to 88%. Return currents and decreases in voltage gradients induced by tow passage likely contributed to the observed fish passage through the EDBS. The efficacy of the EDBS in preventing the passage of small, wild fish is compromised while tows are moving across the barrier system. In particular, downbound tows moving through the EDBS create a pathway for the upstream movement of small fish, and therefore may increase the risk of transfer of invasive fishes from the Mississippi River Basin to the Great Lakes Basin.

Water pollution control technology and strategy for river-lake systems: a case study in Gehu Lake and Taige Canal.

PubMed

Zhang, Yimin; Zhang, Yongchun; Gao, Yuexiang; Zhang, Houhu; Cao, Jianying; Cai, Jinbang; Kong, Xiangji

2011-07-01

The Taoge water system is located in the upstream of Taihu Lake basin and is characterized by its multi-connected rivers and lakes. In this paper, current analyses of hydrology, hydrodynamics and water pollution of Gehu Lake and Taige Canal are presented. Several technologies are proposed for pollution prevention and control, and water environmental protection in the Taihu Lake basin. These included water pollution control integration technology for the water systems of Gehu Lake, Taige Canal and Caoqiao River. Additionally, river-lake water quality and quantity regulation technology, ecological restoration technology for polluted and degraded water bodies, and water environmental integration management and optimization strategies were also examined. The main objectives of these strategies are to: (a) improve environmental quality of relative water bodies, prevent pollutants from entering Gehu Lake and Taige Canal, and ensure that the clean water after the pre-treatment through Gehu Lake is not polluted before entering the Taihu Lake through Taige Canal; (b) stably and efficiently intercept and decrease the pollution load entering the lake through enhancing the river outlet ecological system structure function and water self-purifying capacity, and (c) designate Gehu Lake as a regulation system for water quality and water quantity in the Taoge water system and thus guarantee the improvement of the water quality of the inflow into Taihu Lake.

The failures of root canal preparation with hand ProTaper

PubMed Central

Bătăiosu, Marilena; Diaconu, Oana; Moraru, Iren; Dăguci, C.; Ţuculină, Mihaela; Dăguci, Luminiţa; Gheorghiţă, Lelia

2012-01-01

The failures of root canal preparation are due to some anatomical deviation (canal in “C” or “S”) and some technique errors. The technique errors are usually present in canal root cleansing and shaping stage and are the result of endodontic treatment objectives deviation. Objectives: Our study was made on technique errors while preparing the canal roots with hand ProTaper. Methodology: Our study was made “in vitro” on 84 extracted teeth (molars, premolars, incisors and canines). The canal root of these teeth were cleansed and shaped with hand ProTaper by crown-down technique and canal irrigation with NaOCl(2,5%). The dental preparation control was made by X-ray. Results: During canal root preparation some failures were observed like: canal root overinstrumentation, zipping and stripping phenomenon, discarded and/or fractured instruments. Conclusions: Hand ProTaper represents a revolutionary progress of endodontic treatment, but a deviation from accepted rules of canal root instrumentation can lead to failures of endodontic treatment. PMID:24778848

Problems of drinking water treatment along Ismailia Canal Province, Egypt.

PubMed

Geriesh, Mohamed H; Balke, Klaus-Dieter; El-Rayes, Ahmed E

2008-03-01

The present drinking water purification system in Egypt uses surface water as a raw water supply without a preliminary filtration process. On the other hand, chlorine gas is added as a disinfectant agent in two steps, pre- and post-chlorination. Due to these reasons most of water treatment plants suffer low filtering effectiveness and produce the trihalomethane (THM) species as a chlorination by-product. The Ismailia Canal represents the most distal downstream of the main Nile River. Thus its water contains all the proceeded pollutants discharged into the Nile. In addition, the downstream reaches of the canal act as an agricultural drain during the closing period of the High Dam gates in January and February every year. Moreover, the wide industrial zone along the upstream course of the canal enriches the canal water with high concentrations of heavy metals. The obtained results indicate that the canal gains up to 24.06x10(6) m3 of water from the surrounding shallow aquifer during the closing period of the High Dam gates, while during the rest of the year, the canal acts as an influent stream losing about 99.6x10(6) m3 of its water budget. The reduction of total organic carbon (TOC) and suspended particulate matters (SPMs) should be one of the central goals of any treatment plan to avoid the disinfectants by-products. The combination of sedimentation basins, gravel pre-filtration and slow sand filtration, and underground passage with microbiological oxidation-reduction and adsorption criteria showed good removal of parasites and bacteria and complete elimination of TOC, SPM and heavy metals. Moreover, it reduces the use of disinfectants chemicals and lowers the treatment costs. However, this purification system under the arid climate prevailing in Egypt should be tested and modified prior to application.

Problems of drinking water treatment along Ismailia Canal Province, Egypt*

PubMed Central

Geriesh, Mohamed H.; Balke, Klaus-Dieter; El-Rayes, Ahmed E.

2008-01-01

The present drinking water purification system in Egypt uses surface water as a raw water supply without a preliminary filtration process. On the other hand, chlorine gas is added as a disinfectant agent in two steps, pre- and post-chlorination. Due to these reasons most of water treatment plants suffer low filtering effectiveness and produce the trihalomethane (THM) species as a chlorination by-product. The Ismailia Canal represents the most distal downstream of the main Nile River. Thus its water contains all the proceeded pollutants discharged into the Nile. In addition, the downstream reaches of the canal act as an agricultural drain during the closing period of the High Dam gates in January and February every year. Moreover, the wide industrial zone along the upstream course of the canal enriches the canal water with high concentrations of heavy metals. The obtained results indicate that the canal gains up to 24.06×106 m3 of water from the surrounding shallow aquifer during the closing period of the High Dam gates, while during the rest of the year, the canal acts as an influent stream losing about 99.6×106 m3 of its water budget. The reduction of total organic carbon (TOC) and suspended particulate matters (SPMs) should be one of the central goals of any treatment plan to avoid the disinfectants by-products. The combination of sedimentation basins, gravel pre-filtration and slow sand filtration, and underground passage with microbiological oxidation-reduction and adsorption criteria showed good removal of parasites and bacteria and complete elimination of TOC, SPM and heavy metals. Moreover, it reduces the use of disinfectants chemicals and lowers the treatment costs. However, this purification system under the arid climate prevailing in Egypt should be tested and modified prior to application. PMID:18357626

Cytoskeleton-dependent transport of cytoplasmic particles in previtellogenic to mid-vitellogenic ovarian follicles of Drosophila: time-lapse analysis using video-enhanced contrast microscopy.

PubMed

Bohrmann, J; Biber, K

1994-04-01

In Drosophila oogenesis, several morphogenetic determinants and other developmental factors synthesized in the nurse cells have been shown to accumulate in the oocyte during pre- to mid-vitellogenic stages. However, the mechanisms of the involved intercellular transport processes that seem to be rather selective have not been revealed so far. We have investigated in vitro, by means of video-enhanced contrast time-lapse microscopy, the transport of cytoplasmic particles from the nurse cells through ring canals into the oocyte during oogenesis stages 6-10A. At stage 7, we first observed single particles moving into the previtellogenic oocyte. The particle transfer was strictly unidirectional and seemed to be selective, since only some individual particles moved whereas other particles lying in the vicinity of the ring canals were not transported. The observed transport processes were inhibitable with 2,4-dinitrophenol, cytochalasin B or N-ethylmaleimide, but not with microtubule inhibitors. At the beginning of vitellogenesis (stage 8), the selective translocation of particles through the ring canals became faster (up to 130 nm/second) and more frequent (about 1 particle/minute), whereas during mid-vitellogenesis (stages 9-10A) the velocity and the frequency of particle transport decreased again. Following their more or less rectilinear passage through the ring canals, the particles joined a circular stream of cytoplasmic particles in the oocyte. This ooplasmic particle streaming started at stage 6/7 with velocities of about 80 nm/second and some reversals of direction at the beginning. The particle stream in the oocyte was sensitive to colchicine and vinblastine, but not to cytochalasin B, and we presume that it reflects the rearrangement of ooplasmic microtubules described recently by other authors. We propose that during stages 7-10A, a selective transport of particles into the oocyte occurs through the ring canal along a polarized scaffold of cytoskeletal elements in which microfilaments are involved. This transport might be driven by a myosin-like motor molecule. Either attached to, or organized into, such larger particles or organelles, specific mRNAs and proteins might become selectively transported into the oocyte.

Dynamic Floodplain representation in hydrologic flood forecasting using WRF-Hydro modeling framework

NASA Astrophysics Data System (ADS)

Gangodagamage, C.; Li, Z.; Maitaria, K.; Islam, M.; Ito, T.; Dhondia, J.

2016-12-01

Floods claim more lives and damage more property than any other category of natural disaster in the Continental United States. A system that can demarcate local flood boundaries dynamically could help flood prone communities prepare for and even prevent from catastrophic flood events. Lateral distance from the centerline of the river to the right and left floodplains for the water levels coming out of the models at each grid location have not been properly integrated with the national hydrography dataset (NHDPlus). The NHDPlus dataset represents the stream network with feature classes such as rivers, tributaries, canals, lakes, ponds, dams, coastlines, and stream gages. The NHDPlus dataset consists of approximately 2.7 million river reaches defining how surface water drains to the ocean. These river reaches have upstream and downstream nodes and basic parameters such as flow direction, drainage area, reach slope etc. We modified an existing algorithm (Gangodagamage et al., 2007) to provide lateral distance from the centerline of the river to the right and left floodplains for the flows simulated by models. Previous work produced floodplain boundaries for static river stages (i.e. 3D metric: distance along the main stem, flow depth, lateral distance from river center line). Our new approach introduces the floodplain boundary for variable water levels at each reach with the fourth dimension, time. We use modeled flows from WRF-Hydro and demarcate the right and left lateral boundaries of inundation dynamically by appropriately mapping discharges into hydraulically corrected stages. Backwater effects from the mainstem to tributaries are considered and proper corrections are applied for the tributary inundations. We obtained river stages by optimizing reach level channel parameters using newly developed stream flow routing algorithm. Non uniform inundations are mapped at each NHDplus reach (upstream and downstream nodes) and spatial interpolation is carried out on a normalized digital elevation model (always streams are at zero elevations) to obtain the smooth flood boundaries between adjacent reaches. The validation of the dynamic inundation boundaries is performed using multi-temporal satellite datasets as well as HEC-RAS hydrodynamic model results for selected streams for previous flood events.

Endodontic management of C-shaped root canal system of mandibular first molar by using a modified technique of self-adjusting file system.

PubMed

Helvacioglu-Yigit, Dilek

2015-01-01

C-shaped canal system is a seldom-found root canal anatomy which displays a challenge in all stages of endodontic treatment. According to the literature, this type of canal morphology is not a common finding in the mandibular first molar teeth. This case report presents endodontic management of a mandibular first molar with a C-shaped canal system. Root canal system was cleaned and shaped by nickel-titanium (NiTi) rotary instruments combined with self-adjusting file (SAF). Obturation was performed using warm, vertical condensation combined with the injection of warm gutta-percha. Follow-up examination 12 months later showed that the tooth was asymptomatic. The radiological findings presented no signs of periapical pathology. The clinician must be aware of the occurence and complexity of C-shaped canals in mandibular first molar teeth to perform a successful root canal treatment. The supplementary use of SAF after application of rotary instruments in C-shaped root canals might be a promising approach in endodontic treatment of this type of canal morphology.

Reproductive biology of the Suez Canal spider crab Schizophrys aspera (H. Milne Edwards, 1834: Crustacea: Brachyura: Majidae)

PubMed Central

El-Serehy, Hamed A.; Al-Rasheid, Khaled A.; Ibrahim, Nesreen K.; Al-Misned, Fahad A.

2015-01-01

A reproductive biology study of the spider crab Schizophrys aspera (H. Milne Edwards, 1834) was conducted in the Suez Canal from July 2012 to June 2013. The annual sex ratio (Male:Female) of S. aspera was female biased with values of 1:1.25. Out of the four ovarian development stages of this crab, two stages were observed in the Suez Canal throughout the whole year. The ovigerous crab’s carapace width varied from 28 to 52 mm. This crab species can spawn during most of the year in the canal water, with a peak during late spring and early winter. The fecundity of ovigerous females ranged between 2349 and 13600 eggs with a mean of 5494 ± 1486 eggs. Female crabs that reached sexual maturity exhibited a minimum carapace width varying between 22 and 46 mm, and fifty percentage of all ovigerous females showed a carapace width of 36 mm. PMID:26587008

Reproductive biology of the Suez Canal spider crab Schizophrys aspera (H. Milne Edwards, 1834: Crustacea: Brachyura: Majidae).

PubMed

El-Serehy, Hamed A; Al-Rasheid, Khaled A; Ibrahim, Nesreen K; Al-Misned, Fahad A

2015-11-01

A reproductive biology study of the spider crab Schizophrys aspera (H. Milne Edwards, 1834) was conducted in the Suez Canal from July 2012 to June 2013. The annual sex ratio (Male:Female) of S. aspera was female biased with values of 1:1.25. Out of the four ovarian development stages of this crab, two stages were observed in the Suez Canal throughout the whole year. The ovigerous crab's carapace width varied from 28 to 52 mm. This crab species can spawn during most of the year in the canal water, with a peak during late spring and early winter. The fecundity of ovigerous females ranged between 2349 and 13600 eggs with a mean of 5494 ± 1486 eggs. Female crabs that reached sexual maturity exhibited a minimum carapace width varying between 22 and 46 mm, and fifty percentage of all ovigerous females showed a carapace width of 36 mm.

Ex vivo accuracy of an apex locator using digital signal processing in primary teeth.

PubMed

Leonardo, Mário Roberto; da Silva, Lea Assed Bezerra; Nelson-Filho, Paulo; da Silva, Raquel Assed Bezerra; Lucisano, Marília Pacífico

2009-01-01

The purpose of this study was to evaluate ex vivo the accuracy an electronic apex locator during root canal length determination in primary molars. One calibrated examiner determined the root canal length in 15 primary molars (total=34 root canals) with different stages of root resorption. Root canal length was measured both visually with the placement of a K-file 1 mm short of the apical foramen or the apical resorption bevel, and electronically using an electronic apex locator (Digital Signal Processing). Data were analyzed statistically using the intraclass correlation (ICC) test. Comparing the actual and electronic root canal length measurements in the primary teeth showed a high correlation (ICC=0.95). The Digital Signal Processing apex locator is useful and accurate for apex foramen location during root canal length measurement in primary molars.

Measurement of velocities with an acoustic velocity meter, one side-looking and two upward-looking acoustic Doppler current profilers in the Chicago Sanitary and Ship Canal, Romeoville, Illinois

USGS Publications Warehouse

Oberg, Kevin A.; Duncker, James J.

1999-01-01

In 1998, a prototype 300 kHz, side-looking Acoustic Doppler Current Profiler (ADCP) was deployed in the Chicago Sanitary and Ship Canal (CSSC) at Romeoville, Illinois. Additionally, two upward-looking ADCP's were deployed in the same acoustic path as the side-looking ADCP and in the reach defined by the upstream and downstream acoustic velocity meter (AVM) paths. All three ADCP's were synchronized to the AVM clock at the gaging station so that data were sampled simultaneously. The three ADCP's were deployed for six weeks measuring flow velocities from 0.0 to 2.5 ft/s. Velocities measured by each ADCP were compared to AVM path velocities and to velocities measured by the other ADCP's.

Acceleration induced water removal from ear canals.

NASA Astrophysics Data System (ADS)

Kang, Hosung; Averett, Katelee; Jung, Sunghwan

2017-11-01

Children and adults commonly experience having water trapped in the ear canals after swimming. To remove the water, individuals will shake their head sideways. Since a child's ear canal has a smaller diameter, it requires more acceleration of the head to remove the trapped water. In this study, we theoretically and experimentally investigated the acceleration required to break the surface meniscus of the water in artificial ear canals and hydrophobic-coated glass tubes. In experiments, ear canal models were 3D-printed from a CT-scanned human head. Also, glass tubes were coated with silane to match the hydrophobicity in ear canals. Then, using a linear stage, we measured the acceleration values required to forcefully eject the water from the artificial ear canals and glass tubes. A theoretical model was developed to predict the critical acceleration at a given tube diameter and water volume by using a modified Rayleigh-Taylor instability. Furthermore, this research can shed light on the potential of long-term brain injury and damage by shaking the head to push the water out of the ear canal. This research was supported by National Science Foundation Grant CBET-1604424.

Effectiveness of a redesigned water diversion using rock vortex weirs to enhance longitudinal connectivity for small Salmonids

USGS Publications Warehouse

Martens, Kyle D.; Connolly, Patrick J.

2010-01-01

For nearly 100 years, water diversions have affected fish passage in Beaver Creek, a tributary of the lower Methow River in north-central Washington State. From 2000 to 2004, four dam-style water diversions were replaced with a series of rock vortex weirs (RVWs). The weirs were designed to allow fish passage while maintaining the ability to divert water into irrigation canals. We observed the new appearance of three species (juvenile Chinook salmon Oncorhynchus tshawytscha, juvenile coho salmon O. kisutch, and mountain whitefish Prosopium williamsoni) upstream of the RVWs, indicating successful restoration of longitudinal connectivity. We used passive integrated transponder (PIT) tags and instream PIT tag interrogation systems during 2004–2007 to evaluate upstream passage of small salmonids (<240 mm fork length) through one series of RVWs. We documented 109 upstream passage events by small salmonids through the series of RVWs; most of the events (81%) involved passage of rainbow trout O. mykiss or juvenile steelhead (anadromous rainbow trout). Small rainbow trout or steelhead ranging from 86 to 238 mm (adjusted fork length) were able to pass upstream through the RVWs, although a delay in fish passage at discharges below 0.32 m3/s was detected in comparison with nearby control sections.

Micro-computed tomography visualization of the vestigial alimentary canal in adult oestrid flies.

PubMed

Martín-Vega, D; Garbout, A; Ahmed, F; Ferrer, L M; Lucientes, J; Colwell, D D; Hall, M J R

2018-02-16

Oestrid flies (Diptera: Oestridae) do not feed during the adult stage as they acquire all necessary nutrients during the parasitic larval stage. The adult mouthparts and digestive tract are therefore frequently vestigial; however, morphological data on the alimentary canal in adult oestrid flies are scarce and a proper visualization of this organ system within the adult body is lacking. The present work visualizes the morphology of the alimentary canal in adults of two oestrid species, Oestrus ovis L. and Hypoderma lineatum (de Villiers), with the use of non-invasive micro-computed tomography (micro-CT) and compares it with the highly developed alimentary canal of the blow fly Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae). Both O. ovis and H. lineatum adults showed significant reductions of the cardia and the diameter of the digestive tract, an absence of the helicoidal portion of the midgut typical of other cyclorrhaphous flies, and a lack of crop and salivary glands. Given the current interest in the alimentary canal in adult dipterans in biomedical and developmental biology studies, further understanding of the morphology and development of this organ system in adult oestrids may provide valuable new insights in several areas of research. © 2018 The Royal Entomological Society.

11. Photographic copy of copy of Twin Lakes Outlet Works ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. Photographic copy of copy of Twin Lakes Outlet Works construction drawing dated January 15, 1951. Drawn by W.A. Doe for the Twin Lakes Reservoir and Canal Co. (copy in possession of Bureau of Reclamation, location of original unknown) 'AS CONSTRUCTED' PLANS OF 1949-1950, REHABILITATION OF TWIN LAKES RESERVOIR OUTLET WORKS, DETAILS OF UPSTREAM WING WALLS. - Twin Lakes Dam & Outlet Works, Beneath Twin Lakes Reservoir, T11S, R80W, S22, Twin Lakes, Lake County, CO

Continuous Temperature and Water-Level Data Collected for a Heat Tracer Study on a Selected Reach of Tri-State Canal, Western Nebraska, 2007

USGS Publications Warehouse

Hobza, Christopher M.

2008-01-01

The water supply in parts of the North Platte River Basin in the Nebraska Panhandle has been designated as fully appropriated or over appropriated by the Nebraska Department of Natural Resources. Recent legislation (LB 962) requires the North Platte Natural Resources District and the Nebraska Department of Natural Resources to develop an Integrated Management Plan to balance ground- and surface-water supply and demand within the North Platte Natural Resources District. For a ground-water-flow model to accurately simulate existing or future ground-water and surface-water conditions, accurate estimates of specific input variables such as streambed conductance or canal-seepage rates are required. As of 2008, the values input into ground-water models were estimated on the basis of interpreted lithology from test holes and geophysical surveys. Often, contrasts of several orders of magnitude exist for streambed conductance among the various sediment textures present locally, and thin, near-surface layers of fine sediment can clog the streambed, substantially reducing conductance. To accurately quantify the rates of leakage from irrigation canals and estimate ground-water recharge, the U.S. Geological Survey, in cooperation with the North Platte Natural Resources District, collected continuous temperature and water-level data to use heat as a tracer for a selected reach of Tri-State Canal west of Scottsbluff, Nebraska. Continuous records of subsurface temperature, ground-water level, canal stage, and water temperature, and sediment core data are presented in this report. Subsurface temperature was monitored at four vertical sensor arrays of thermocouples installed at various depths beneath the canal bed from March through September 2007. Canal stage and water temperature were measured from June to September 2007. Ground-water level was recorded continuously in an observation well drilled near the subsurface temperature monitoring site. These data sets were collected for use as inputs for a computer model to estimate the vertical hydraulic conductivity. Before the initiation of flow, diurnal variations in subsurface temperature occurred because of daytime heating and nighttime cooling of bed sediment. Flow in Tri-State Canal was first detected on June 16 at the monitoring site as a disruption in the temperature signal in the shallowest thermocouple in all four vertical sensor arrays. This disruption in the temperature pattern occurred in deeper thermocouples at slightly later times during the rapid infiltration of canal water. The ground-water level began to rise approximately 23 hours after flow was first detected at the monitoring site. Canal stage rose for 7 days until the maximum flow capacity of the canal was approached on June 23, 2007. Measured water temperatures ranged from 18 to 25 degrees Celsius (C) while the canal was flowing near maximum capacity. Small diurnal variations of 1.0 to 1.5 degrees C in water temperature were recorded during this time. Measured ground-water levels rose constantly during the entire irrigation season until levels peaked on September 3, 2007, 3 days after diversions to Tri-State Canal ceased.

Temperature inverted haloclines provide winter warm-water refugia for manatees in southwest Florida

USGS Publications Warehouse

Stith, Bradley M.; Reid, James P.; Langtimm, Catherine A.; Swain, Eric D.; Doyle, Terry J.; Slone, Daniel H.; Decker, Jeremy D.; Soderqvist, Lars E.

2010-01-01

Florida manatees (Trichechus manatus latirostris) overwintering in the Ten Thousand Islands and western Everglades have no access to power plants or major artesian springs that provide warm-water refugia in other parts of Florida. Instead, hundreds of manatees aggregate at artificial canals, basins, and natural deep water sites that act as passive thermal refugia (PTR). Monitoring at two canal sites revealed temperature inverted haloclines, which provided warm salty bottom layers that generally remained above temperatures considered adverse for manatees. At the largest PTR, the warmer bottom layer disappeared unless significant salt stratification was maintained by upstream freshwater inflow over a persistent tidal wedge. A detailed three-dimensional hydrology model showed that salinity stratification inhibited vertical convection induced by atmospheric cooling. Management or creation of temperature inverted haloclines may be a feasible and desirable option for resource managers to provide passive thermal refugia for manatees and other temperature sensitive aquatic species.

Multi-stage fuel cell system method and apparatus

DOEpatents

George, Thomas J.; Smith, William C.

2000-01-01

A high efficiency, multi-stage fuel cell system method and apparatus is provided. The fuel cell system is comprised of multiple fuel cell stages, whereby the temperatures of the fuel and oxidant gas streams and the percentage of fuel consumed in each stage are controlled to optimize fuel cell system efficiency. The stages are connected in a serial, flow-through arrangement such that the oxidant gas and fuel gas flowing through an upstream stage is conducted directly into the next adjacent downstream stage. The fuel cell stages are further arranged such that unspent fuel and oxidant laden gases too hot to continue within an upstream stage because of material constraints are conducted into a subsequent downstream stage which comprises a similar cell configuration, however, which is constructed from materials having a higher heat tolerance and designed to meet higher thermal demands. In addition, fuel is underutilized in each stage, resulting in a higher overall fuel cell system efficiency.

Diagnosis and Diagnostic Imaging of Anal Canal Cancer.

PubMed

Ciombor, Kristen K; Ernst, Randy D; Brown, Gina

2017-01-01

Anal canal cancer is an uncommon malignancy but one that is often curable with optimal therapy. Owing to its unique location, histology, risk factors, and usual presentation, a careful diagnostic approach is warranted. This approach includes an excellent history and physical examination, including digital rectal examination, laboratory data, and comprehensive imaging. Anal cancer staging and formulation of a treatment plan depends on accurate imaging data. Modern radiographic techniques have improved staging quality and accuracy, and a thorough knowledge of anal anatomy is paramount to the optimal multidisciplinary treatment of this disease. Copyright © 2016 Elsevier Inc. All rights reserved.

Geohydrology of the cross-Florida barge canal area, with special reference to the Ocala vicinity

USGS Publications Warehouse

Faulkner, Glen L.

1973-01-01

The Cross-Florida Barge Canal route commences at Palatka on the St. Johns River, about 75 miles upstream from the Atlantic Ocean, and extends 110 miles southwestward across Peninsular Florida into deep water in the Gulf of Mexico near Yankeetown. The canal will be equipped with five locks, each 600 feet long and 84 feet wide, and the channel will be a minimum of 12 feet deep and 150 feet wide. From near Ocala northeastward, the canal channel will replace much of the natural channel of the Oklawaha River, and will be excavated into beds of the so-called shallow sand aquifer of Miocene age and younger, which overlies limestone of the Floridan aquifer. Westward from Ocala, most of the canal will be excavated below the potentiometric surface into limestone and dolomite of the Floridan aquifer. Water levels of Rodman, Eureka, and Inglis Pools will be controlled by dams and spillways with the limited exchange of water between the pools and the aquifers. The water levels in the Summit Pools will fluctuate with the natural changes in the ground-water level of the Floridan aquifer, although the stage of the pool will be controlled partly by the stage held in the Eureka Pool. A dynamic inflow-outflow relationship will exist between the Summit Pool and the Floridan aquifer. The Floridan aquifer in the canal area is 1,000 to 1,200 feet thick and consists of limestone and dolomite of middle Eocene Miocene age, including from older to younger, the Lake City, Avon Park, and Ocala limestones plus permeable sandy, dolomitic limestone in the lower part of the Hawthorn Formation. It is possible that most of the flow to the two major springs in the area occurs in the upper 100 feet or so of the aquifer in the Ocala Limestone. The aquifer is underlain by the Oldsmar limestone of early Eocene age and is overlain by sand, clayey sand, clay and shell beds of Miocene through Holocene age, in thickness from a few feet to 300 feet. The permeable beds overlying the Floridan aquifer constitute the shallow aquifer, while the poorly permeable ones act as confining beds where the Floridan aquifer is under artesian conditions. A north-south line drawn separating the head of Silver Springs on the west from the Oklawaha River on the east marks the approximate western limit of a continuous blanket of materials of Miocene-Pliocene(?) age covering the rocks of the Floridan aquifer. East of the line, much of the aquifer is under artesian conditions, particularly in the Oklawaha River valley, although in some areas east of the valley, direct recharge through thick permeable Miocene-Pliocene(?) sands occurs. West of the line, only scattered remnants of a once continuous Miocene-Pliocene(?) cover remain. Lack of the cover is a result of erosion on the crest and flank of the Ocala Uplift, a broad northwest-southeast trending anticlinal upwarp, the axis of which is crossed by the canal route in the Dunnellon area. Over most of this area the Floridan aquifer is unconfined and receives direct recharge through a cover of a few tens of feet of sand and clayey sand of Quaternary age. Tensional stresses during the structural evolution of the Ocala Uplift produced an intersecting system of fractures and normal faults in rocks of the Floridan aquifer. The fractures and faults are important controls for orientation of solution channels and, therefore, for development of ground-water circulation patterns. When the system surface streams, which once drained the Barge Canal area, eroded the poorly permeable Miocene-Pliocene(?) cover from the flanks of the Ocala Uplift, surface runoff was reduced and precipitation began to directly infiltrate the underlying limestones. Now only principal streams remain, such as the Oklawaha and Withlacoochee Rivers and a few short tributaries, while one of the most highly developed subsurface drainage systems in the world has evolved in cavernous limestone of the Floridan aquifer. Two of the larger freshwater springs in the world now

Geohydrology of the Cross-Florida Barge Canal area, with special reference to the Ocala vicinity

USGS Publications Warehouse

Faulkner, Glen L.

1970-01-01

The Cross-Florida Barge Canal route commences at Palatka on the St. Johns River, about 75 miles upstream from the Atlantic Ocean, and extends 110 miles southwestward across Peninsular Florida into deep water in the Gulf of Mexico near Yankeetown. The canal will be equipped with five locks, each 600 feet long and 84 feet wide, and the channel will be a minimum of 12 feet deep and 150 feet wide. From near Ocala northeastward, the canal channel will replace much of the natural channel of the Oklawaha River, and will be excavated into beds of the so-called shallow sand aquifer of Miocene and younger age, which overlies limestone of the Floridan aquifer. Westward from Ocala most of the canal will be excavated below the potentiometric surface into limestone and dolomite of the Floridan aquifer. Water levels of Rodman, Eureka, and Inglis Pools will be controlled by dams and spillways with limited exchange of water between the pools and the aquifers. The water levels in the Summit Pool will fluctuate with the natural changes in the ground-water level of the Floridan aquifer, although the stage of the pool will be partially controlled by the stage held in the Eureka Pool. A dynamic inflow-outflow relationship will exist between the Sun, nit Pool and the Floridan aquifer. The Floridan aquifer in the canal area is 1,000 to 1,200 feet thick and consists of limestone and dolomite of middle Eocene to Miocene age, including, from older to younger the Lake City, Avon Park and Ocala limestones plus permeable sandy, dolomitic limestone in the lower part of the Hawthorn Formation. It is possible that most of the flow to the two major springs in the area occurs in the upper 100 feet or so of the aquifer in the Ocala Limestone. The aquifer is underlain by the Oldsmar Limestone of early Eocene age and is overlain by sand, clayey sand, clay and shell beds of Miocene through Holocene age, ranging from a few feet to two or three hundred feet thick. The permeable beds overlying the Floridan aquifer constitute the shallow aquifer, while the poorly permeable ones act as confining beds where the Floridan aquifer is under artesian conditions. A north-south line drawn separating the head of Silver Springs on the west from the Oklawaha River on the east marks the approximate westward limit of a continuous blanket of Miocene-Pliocene(?) age materials covering the rocks of the Floridan aquifer. East of the line much of the aquifer is under artesian conditions, particularly in the Oklawaha River valley, although in some areas east of the valley direct recharge through thick permeable Miocene-Pliocene(?) sands occurs. West of the line, only scattered remnants of a once continuous Miocene-Pliocene(?) cover remains. Lack of the cover is a result of erosion on the crest and flanks of the Ocala Uplift, a broad northwest-southeast trending anticlinal upwarp, the axis of which is crossed by the canal route in the Dunnellon area. Over most of this area the Floridan aquifer is unconfined, and receives direct recharge through a cover of a few tens of feet of sand and clayey sand of Quaternary age. Tensional stresses during the structural evolution of the Ocala Uplift produced an intersecting system of fractures and normal faults in rocks of the Florida Aquifer. The fractures and faults are important controls for orientation of solution channels, and, therefore, for development of ground-water circulation patterns. When the system of surface streams which once drained the Barge Canal area eroded the poorly permeable Miocene-Pliocene(?) cover from the flanks of the Ocala Uplift, surface runoff was reduced and precipitation began to directly infiltrate the underlying limestones. Now only principal rivers, such as the Oklawaha and Withlacoochee Rivers, and a few short tributaries remain, while one of the most highly developed subsurface drainage systems in the world has evolved in the cavernous limestones of the Floridan aquifer. Two of the larger fresh water spr

Source identification of Florida Bay's methylmercury problem: Mainland runoff versus atmospheric deposition and in situ production

USGS Publications Warehouse

Rumbold, Darren G.; Evans, David W.; Niemczyk, Sharon; Fink, Larry E.; Laine, Krysten A.; Howard, Nicole; Krabbenhoft, David P.; Zucker, Mark

2011-01-01

The first advisory to limit consumption of Florida Bay fish due to mercury was issued in 1995. Studies done by others in the late 1990s found elevated water column concentrations of both total Hg (THg) and methylmercury (MeHg) in creeks discharging from the Everglades, which had its own recognized mercury problem. To investigate the significance of allochthonous MeHg discharging from the upstream freshwater Everglades, we collected surface water and sediment along two transects from 2000 to 2002. Concentrations of THg and MeHg, ranging from 0.36 ng THg/L to 5.98 ng THg/L and from <0.02 ng MeHg/L to 1.79 ng MeHg/L, were elevated in the mangrove transition zone when compared both to upstream canals and the open waters of Florida Bay. Sediment concentrations ranged from 5.8 ng THg/g to 145.6 ng THg/g and from 0.05 ng MeHg/g to 5.4 ng MeHg/g, with MeHg as a percentage of THg occasionally elevated in the open bay. Methylation assays indicated that sediments from Florida Bay have the potential to methylate Hg. Assessment of mass loading suggests that canals delivering stormwater from the northern Everglades are not as large a source as direct atmospheric deposition and in situ methylation, especially within the mangrove transition zone.

Reservoir and canal system regulation for operation of the Raymond Reservoir Hydro Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, H.D.; Davidson, B.

1995-12-31

In 1989 LIMA Engineering Ltd. of Lethbridge, Alberta, Canada and Tudor Engineering Company of Oakland, California investigated the feasibility of installing a hydroelectric facility for the St. Mary River Irrigation District at Raymond Chute. This chute is a 29.3 m (96 ft) drop structure on the District`s main canal outside of the town of Raymond in southern Alberta. The chute discharges into the east end of Raymond Reservoir, a small regulating reservoir. The engineering team concluded that the project could be made more attractive by combining the drop at Raymond Chute with an additional 17.7 m (58 ft) of headmore » available at the upstream Milk River Ridge Reservoir. The result was the 20 MW Raymond Reservoir Hydro Project which went into commercial operation in May, 1994. Combining these two drops in elevation required the construction of a complete bypass system with a new approach canal and tailrace discharging into the west end of Raymond Reservoir, approximately 5 km (3 miles) west of the Raymond Chute. The system allows up to 56.7 cms (2,000 cfs) to be diverted through the powerhouse and thereby bypass Milk River Ridge Reservoir, Raymond Chute and approximately 6.5 km (4 miles) of canal. No synchronous bypass valve or spill facility was provided at the powerhouse. Rather, a system of rehabilitated or new check structures and controls were provided to automatically transfer flow from the power canal to the original system and thereby maintain a constant pre-set discharge downstream of the powerhouse following load rejections. This constant discharge is essential for meeting downstream irrigation demand.« less

Repeatability and Genotype x Environment Interaction of Intermediate Stage Sugarcane Selection Conducted on Sand and Organic soils

USDA-ARS?s Scientific Manuscript database

The Florida cooperative sugarcane cultivar development program conducts all of its early selection stages on muck (organic) soils at the USDA-ARS Sugarcane Field Station in Canal Point. About 25% of the locations in the final two stages (Stages 3 and 4) are conducted on sand soils, after a reduction...

Life-stage-specific physiology defines invasion extent of a riverine fish

USGS Publications Warehouse

Lawrence, David J.; Beauchamp, David A.; Olden, Julian D.

2015-01-01

Many ecologists have called for mechanism-based investigations to identify the underlying controls on species distributions. Understanding these controls can be especially useful to construct robust predictions of how a species range may change in response to climate change or the extent to which a non-native species may spread in novel environments.Here, we link spatially intensive observations with mechanistic models to illustrate how physiology determines the upstream extent of the aquatic ectotherm smallmouth bass (Micropterus dolomieu) in two headwater rivers.Our results demonstrate that as temperatures become increasingly cold across a downstream to upstream gradient, food consumption in age 0 bass becomes increasingly constrained, and as a result, these fish become growth limited. Sufficient first summer growth of age 0 bass is essential for overwinter survival because young bass must persist from energy reserves accumulated during the summer, and those reserves are determined by body size.Our field data reveal the upstream extent of adult bass reproduction corresponds to a point in the downstream/upstream gradient where cold temperatures impair growth opportunities in young bass. This pattern was repeated in both study streams and explained why bass positioned nests twice as far upstream in the warm compared to the cold stream in the same basin. Placement of spawning nests by adult bass is likely subject to strong evolutionary selection in temperate systems: if bass spawn too far upstream, their young are unlikely to grow large enough to survive the winter. Consumption and growth in older bass (age 3–4) was far less sensitive to temperature. Based on these data, we suggest that temperature-sensitive age 0 bass constrain the upstream distribution limits of bass within temperate streams.In this study, we investigated how temperature-dependent physiology changed through the life history of a species and, in doing so, identified a climate-sensitive life-history stage that likely sets the distributional limits of all other life-history stages. We anticipate the framework developed here could be employed to identify how similar stage-specific environmental sensitivity determines distribution in many other ectothermic species.

Stochastic analyses to identify wellfield withdrawal effects on surface-water and groundwater in Miami-Dade County, Florida.

PubMed

Swain, Eric

2012-12-30

Several stochastic analyses were conducted in Miami-Dade County, Florida, to evaluate the effects of wellfield withdrawal on aquifer water levels, canal stage, and canal flow. Multiyear data for withdrawals at four water-supply wellfields, water levels at the S-121 canal control structure and groundwater head at a nearby monitoring well were used to determine the interrelation between wellfield withdrawals and water levels in the canal and aquifer. A spectral analysis was performed first on the wellfield withdrawals, showing similar patterns of fluctuations, but no well-defined seasonality. In order to compare water-level response with withdrawals at each wellfield, the intercorrelation effects between wellfields was removed through a 'causal chain' approach where the inter-wellfield correlation is used to isolate the wellfield/water-level correlation. Most computed correlations have magnitudes less than 5 percent, but with statistical significance above 90 percent. Results indicate that withdrawals from the wellfields most distant from the canal had no significant correlation to the canal levels. However the highest correlation was not at the wellfield closest to the canal, but at the two wellfields at the intermediate distance that have higher withdrawal rates. The hydraulic interconnectivity of the canal with the rest of the canal network, covering the study area, allows the canal equalizes with all connected canals. This explains why proximity to a particular canal location does not appear to be as important a factor as the withdrawal rate. Groundwater levels are more highly correlated to a wellfield on the same side of the canal, and to pumping wells in the same wellfield on the same side of the canal. This indicates that canals are an effective barrier and source/sink for the groundwater. Further nonlinear correlation analysis indicates that high withdrawal rates disproportionally affect water levels and are the predominant effect on the canal. Published by Elsevier Ltd.

4D Floodplain representation in hydrologic flood forecasting using WRFHydro modeling framework

NASA Astrophysics Data System (ADS)

Gangodagamage, C.; Li, Z.; Adams, T.; Ito, T.; Maitaria, K.; Islam, M.; Dhondia, J.

2015-12-01

Floods claim more lives and damage more property than any other category of natural disaster in the Continental U.S. A system that can demarcate local flood boundaries dynamically could help flood prone communities prepare for and even prevent from catastrophic flood events. Lateral distance from the centerline of the river to the right and left floodplains for the water levels coming out of the models at each grid location have not been properly integrated with the national hydrography dataset (NHDPlus). The NHDPlus dataset represents the stream network with feature classes such as rivers, tributaries, canals, lakes, ponds, dams, coastlines, and stream gages. The NHDPlus dataset consists of approximately 2.7 million river reaches defining how surface water drains to the ocean. These river reaches have upstream and downstream nodes and basic parameters such as flow direction, drainage area, reach slope etc. We modified an existing algorithm (Gangodagamage et al., 2007, 2011) to provide lateral distance from the centerline of the river to the right and left floodplains for the flows simulated by models. Previous work produced floodplain boundaries for static river stages (i.e. 3D metric: distance along the main stem, flow depth, lateral distance from river center line). Our new approach introduces the floodplain boundary for variable water levels with the fourth dimension, time. We use modeled flows from WRFHydro and demarcate the right and left lateral boundaries of inundation dynamically. This approach dynamically integrates with high resolution models (e.g., hourly and ~ 1 km spatial resolution) that are developed from recent advancements in high computational power with ground based measurements (e.g., Fluxnet), lateral inundation vectors (direction and spatial extent) derived from multi-temporal remote sensing data (e.g., LiDAR, WorldView 2, Landsat, ASTER, MODIS), and improved representations of the physical processes through multi-parameterizations. Our approach enhances the normalized (streams are at zero elevations) DEM derived upstream flow routing pathways for stream reaches for given water stages as more and more satellite data become available for various flood inundations. Validation of the inundation boundaries is performed using HEC-RAS hydrodynamic model results for selected streams.

Overt and occult vidian canal involvement in juvenile angiofibroma and its possible impact on recurrence.

PubMed

Thakar, Alok; Hota, Ashutosh; Bhalla, Ashu Seth; Gupta, Siddharth Datta; Sarkar, Chitra; Kumar, Rakesh

2016-04-01

Postexcision residual disease in the vidian canal is speculated to contribute to recurrence in juvenile angiofibroma. We composed a prospective cohort of 16 consecutive patients with juvenile angiofibroma (stages IIA-IIIB). The presurgical vidian canal assessment was done by contrast-enhanced CT (1.2 mm collimation). At surgery after complete tumor excision, the vidian canal tissue was sampled for histology. Postexcision drilling of the vidian canal was done in 8 of 15 patients to remove microscopic residual disease, with a 24 to 48 month follow-up period. Presurgical radiology indicated ipsilateral vidian canal enlargement (≥3 mm)/destruction in 13 of 16 patients. Radiologically occult involvement was documented only by histology in another 1 of 16 patients. Postexcision sampling of the vidian canal noted microscopic residual tumor in 3 of 15 patients. No recurrences were noted in 8 cases (0 of 8) with postexcision drilling of the vidian canal and 2 recurrences in 7 cases (2 of 7) with no drilling (p = .20). Vidian canal involvement in juvenile angiofibroma is almost universal (14 of 16) and may be occult to CT evaluation. The site may harbor microscopic residual tumor after seemingly complete excision. Surgical attention toward it may reduce recurrences. © 2015 Wiley Periodicals, Inc. Head Neck 38: E421-425, 2016. © 2015 Wiley Periodicals, Inc.

Quantifying canal leakage rates using a mass-balance approach and heat-based hydraulic conductivity estimates in selected irrigation canals, western Nebraska, 2007 through 2009

USGS Publications Warehouse

Hobza, Christopher M.; Andersen, Michael J.

2010-01-01

The water supply in areas of the North Platte River Basin in the Nebraska Panhandle has been designated as fully appropriated or overappropriated by the Nebraska Department of Natural Resources (NDNR). Enacted legislation (Legislative Bill 962) requires the North Platte Natural Resources District (NPNRD) and the NDNR to develop an Integrated Management Plan (IMP) to balance groundwater and surface-water supply and demand in the NPNRD. A clear understanding of the groundwater and surface-water systems is critical for the development of a successful IMP. The primary source of groundwater recharge in parts of the NPNRD is from irrigation canal leakage. Because canal leakage constitutes a large part of the hydrologic budget, spatially distributing canal leakage to the groundwater system is important to any management strategy. Surface geophysical data collected along selected reaches of irrigation canals has allowed for the spatial distribution of leakage on a relative basis; however, the actual magnitude of leakage remains poorly defined. To address this need, the U.S. Geological Survey, in cooperation with the NPNRD, established streamflow-gaging stations at upstream and downstream ends from two selected canal reaches to allow a mass-balance approach to be used to calculate daily leakage rates. Water-level and sediment temperature data were collected and simulated at three temperature monitoring sites to allow the use of heat as a tracer to estimate the hydraulic conductivity of canal bed sediment. Canal-leakage rates were estimated by applying Darcy's Law to modeled vertical hydraulic conductivity and either the estimated or measured hydraulic gradient. This approach will improve the understanding of the spatial and temporal variability of canal leakage in varying geologic settings identified in capacitively coupled resistivity surveys. The high-leakage potential study reach of the Tri-State Canal had two streamflow-gaging stations and two temperature monitoring sites along its length. Calculated leakage rates from the mass-balance approach varied from year to year and were generally dependent on local climatic conditions, and the timing and magnitude of the initial seasonal diversion into the Tri-State Canal. Leakage rates ranged from 0.98 meter per day (m/d) on June 22, 2007, to about to 0 m/d during July 2009. Drier conditions generally resulted in higher leakage rates because of reduced flow from Spottedtail Creek, lower groundwater levels near Spottedtail Creek, and no unmeasured flow entering the reach. Of the three years studied (2007-09), 2007 was the driest, and therefore had the highest canal leakage rates. The moderately low leakage potential study reach of Interstate Canal had two streamflow-gaging stations and one temperature monitoring site along its length. Excluding the leakage calculations from early May 2007, leakage rates ranged from 0.08 to 0.7 m/d. Less variability in leakage from year to year indicates that climatic conditions may have less of an effect for Interstate Canal compared to Tri-State Canal. This may be because Interstate Canal was cut into the northern edge of the North Platte alluvial valley and consequently the canal bed is well above the local groundwater table resulting in a constant (1 meter per meter [m/m]) hydraulic gradient. Interstate Canal also does not receive any captured flow that can vary substantially year to year. Two temperature monitoring sites were installed within the high-leakage potential reach of Tri-State Canal. Site TCTEMP1 was established in 2007 where the water table was well below the canal bed surface. The vertical hydraulic conductivity of the poorly sorted sand and gravel beneath site TCTEMP1 was estimated using a calibrated one-dimensional VS2DH model. Using a trial-and-error approach, the best-fit vertical hydraulic conductivity for the site TCTEMP1 model domain was 1.1 m/d. Site TCTEMP2 was established at the mouth of Spottedtail Creek where a shallow

Vertical Load Induced with Twisted File Adaptive System during Canal Shaping.

PubMed

Jamleh, Ahmed; Alfouzan, Khalid

2016-12-01

To evaluate the vertical load induced with the Twisted File Adaptive (TFA; SybronEndo, Orange, CA) system during canal shaping of extracted teeth by comparing it with the Twisted File (TF, SybronEndo), ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), and ProTaper Universal (PTU, Dentsply Maillefer) systems. Fifty-two root canals were shaped using the TFA, TF, PTN, or PTU systems (n = 13 for each system). They were shaped gently according to the manufacturers' instructions. During canal shaping, vertical loads were recorded and shown in 2 directions, apically and coronally directed loads. The vertical peak loads of 3 instrumentation stages were used for comparison. The effects of rotary systems on the mean positive and negative peak loads were analyzed statistically using the Kruskal-Wallis and Mann-Whitney tests at a confidence level of 95%. The overall pattern of the instantaneous loads appeared to increase with the use of successive instruments within the system. During canal shaping in all groups, the apically and coronally directed peak loads ranged from 0.84-7.55 N and 2.16-2.79 N, respectively. There were significant differences in both peak loads among the tested systems at each instrumentation stage. TFA had the lowest apically directed peak loads. In terms of coronally directed peak loads, the TFA and TF had a significantly lower amount of loads developed with their instruments than PTN and PTU. The choice of instrument system had an influence on the loads developed during canal shaping. TFA instruments were associated favorably with the lowest values of peak loads followed by TF, PTN, and PTU. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Toxicity evaluation of natural samples from the vicinity of rice fields using two trophic levels.

PubMed

Marques, Catarina R; Pereira, Ruth; Gonçalves, Fernando

2011-09-01

An ecotoxicological screening of environmental samples collected in the vicinity of rice fields followed a combination of physical and chemical measurements and chronic bioassays with two freshwater trophic levels (microalgae: Pseudokirchneriella subcapitata and Chlorella vulgaris; daphnids: Daphnia longispina and Daphnia magna). As so, water and sediment/soil elutriate samples were obtained from three sites: (1) in a canal reach crossing a protected wetland upstream, (2) in a canal reach surrounded by rice fields and (3) in a rice paddy. The sampling was performed before and during the rice culture. During the rice cropping, the whole system quality decreased comparatively to the situation before that period (e.g. nutrient overload, the presence of pesticides in elutriates from sites L2 and L3). This was reinforced by a significant inhibition of both microalgae growth, especially under elutriates. Contrary, the life-history traits of daphnids were significantly stimulated with increasing concentrations of water and elutriates, for both sampling periods.

The effect of anthropogenic activities to the decrease of water quality

NASA Astrophysics Data System (ADS)

Sidabutar, N. V.; Namara, I.; Hartono, D. M.; Soesilo, T. E. B.

2017-05-01

The raw water in Jakarta is supplied from Jatiluhur Dam, which is distributed pass through West Tarum Canal with an open canal about 70 km long. This water quality does not meet the standard set by the government and heavily polluted by anthropogenic activities along its river. This research uses a quantitative research approach with the mix-method. This research did an in-depth interview with inhabitants along the riverbank about their daily activity. The water along the riverbank is polluted by anthropogenic activities, such as: first: domestic activities (washing, cooking, and bathing), second: littering into the river, and third: discharging waste water from households into the river. This present research measures water quality for parameters pH, temperature, Dissolved Oxygen (DO), Chemical Oxygen Demand (COD), Total Dissolved Solid (TDS), Total Suspended Solid (TSS), and Fecal coliform. In this social segment, it is shown that pH, DO, TDS and Fecal coliformin the downstream part are worse than in the upstream.

Ultrasound follow-up of infantile hypertrophic pyloric stenosis (IHPS) during conservative therapy: ultrasound findings as criteria for diagnosis and cure.

PubMed

Miura, Sachiko; Haku, Eijitsu; Hirai, Toshiko; Marugami, Nagaaki; Itoh, Takahiro; Tanaka, Takehiro; Kichikawa, Kimihiko; Ohishi, Hajime

2008-06-01

During conservative therapy of infantile hypertrophic pyloric stenosis (IHPS) with atropine sulfate, there are many patients who do not achieve normal values of pyloric wall thickness and canal length even though they are clinically cured (vomiting has ceased); an objective criterion for cure has not yet been established. The aim of this study was to examine whether the appearance of pyloric wall stratification can be used as a criterion for cure. Twenty infants with IHPS who were treated conservatively were enrolled. Two of them ultimately required surgery. Ultrasound examinations were done serially and the pyloric wall thickness and canal length were measured. The echogenicity of the pyloric wall and the presence of wall stratification were noted. On admission, all infants satisfied the ultrasound criteria for IHPS and had a heterogeneous pyloric wall without stratification. With conservative therapy, symptoms disappeared, the pyloric wall thickness and the canal length gradually decreased, the echogenicity gradually became homogeneous and hypoechoic, and wall stratification appeared (in most cases before the pyloric wall thickness and the canal length had normalized). The absence of wall stratification suggests that cellular interstitial changes, such as edema or inflammation, are present in the pyloric wall in the acute stage. Pyloric wall stratification was absent during the acute stage, but it appeared after initiation of treatment but before the pyloric wall thickness and the canal length had normalized. The presence of pyloric wall stratification can be used as a criterion for cure; the absence of wall stratification can be added to ultrasound diagnostic criteria for IHPS.

Laser velocimeter measurements of the flow downstream of the Space Shuttle Main Engine high pressure oxidizer turbopump first-stage turbine nozzle

NASA Technical Reports Server (NTRS)

Ferguson, T. V.; Havskjold, G. L.; Rojas, L.

1988-01-01

A laser two-focus velocimeter was used in an open-loop water test facility in order to map the flowfield downstream of the SSME's high-pressure oxidizer turbopump first-stage turbine nozzle; attention was given to the effects of the upstream strut-downstream nozzle configuration on the flow at the rotor inlet, in order to estimate dynamic loads on the first-stage rotor blades. Velocity and flow angles were plotted as a function of circumferential position, and were found to clearly display the periodic behavior of the wake flow field. The influence of the upstream centerbody-supporting struts on the vane nozzle wake pattern was evident.

WRKY23 is a component of the transcriptional network mediating auxin feedback on PIN polarity

PubMed Central

Vasileva, Mina; Sauer, Michael

2018-01-01

Auxin is unique among plant hormones due to its directional transport that is mediated by the polarly distributed PIN auxin transporters at the plasma membrane. The canalization hypothesis proposes that the auxin feedback on its polar flow is a crucial, plant-specific mechanism mediating multiple self-organizing developmental processes. Here, we used the auxin effect on the PIN polar localization in Arabidopsis thaliana roots as a proxy for the auxin feedback on the PIN polarity during canalization. We performed microarray experiments to find regulators of this process that act downstream of auxin. We identified genes that were transcriptionally regulated by auxin in an AXR3/IAA17- and ARF7/ARF19-dependent manner. Besides the known components of the PIN polarity, such as PID and PIP5K kinases, a number of potential new regulators were detected, among which the WRKY23 transcription factor, which was characterized in more detail. Gain- and loss-of-function mutants confirmed a role for WRKY23 in mediating the auxin effect on the PIN polarity. Accordingly, processes requiring auxin-mediated PIN polarity rearrangements, such as vascular tissue development during leaf venation, showed a higher WRKY23 expression and required the WRKY23 activity. Our results provide initial insights into the auxin transcriptional network acting upstream of PIN polarization and, potentially, canalization-mediated plant development. PMID:29377885

Simulated Water-Management Alternatives Using the Modular Modeling System for the Methow River Basin, Washington

USGS Publications Warehouse

Konrad, Christopher P.

2004-01-01

A precipitation-runoff model for the Methow River Basin was used to simulate six alternatives: (1) baseline of current flow, (2) line irrigation canals to limit seepage losses, (3) increase surface-water diversions through unlined canals for aquifer recharge, (4) convert from surface-water to ground-water resources to supply water for irrigation, and (5) reduce tree density in forested headwater catchments, and (6) natural flow. Daily streamflow from October 1, 1959, to September 30, 2001 (water years 1960?2001) was simulated. Lining irrigation canals (alternative 2) increased flows in the Chewuch, Twisp, and the Methow (upstream and at Twisp) Rivers during September because of lower diversion rates, but not in the Methow River near Pateros. Increasing diversions for aquifer recharge (alternative 3) increased streamflow from September into January, but reduced streamflow earlier in the summer. Conversion of surface-water diversions to ground-water wells (alternative 4) resulted in the largest increase in September streamflow of any alternative, but also marginally lower January flows (at most -8 percent in the 90-percent exceedence value). Forest-cover reduction (alternative 5) produced large increases in streamflow during high-flow periods in May and June and earlier onset of high flows and small increases in January streamflows. September streamflows were largely unaffected by alternative 5. Natural streamflow (alternative 6) was higher in September and lower in January than the baseline alternative.

Incidence and survival patterns of rare anal canal neoplasms using the surveillance epidemiology and end results registry.

PubMed

Metildi, Cristina; McLemore, Elisabeth C; Tran, Thuy; Chang, David; Cosman, Bard; Ramamoorthy, Sonia L; Saltzstein, Sidney L; Sadler, Georgia Robins

2013-10-01

Small cell, neuroendocrine tumors, and melanoma of the anus are rare. Limited data exist on the incidence and management for these rare tumors. A large, prospective, population-based database was used to determine incidence and survival patterns of rare anal neoplasms. The Surveillance, Epidemiology and End Results registry was queried to identify patients diagnosed with anal canal neoplasms. Incidence and survival patterns were evaluated with respect to age, sex, race, histology, stage, and therapy. We identified 7078 cases of anal canal neoplasms: melanoma (n = 149), neuroendocrine (n = 61), and small cell neuroendocrine (n = 26). Squamous cell carcinoma (SCC) (n = 6842) served as the comparison group. Anal melanoma (AM) demonstrated the lowest survival rate at 2.5 per cent. Neuroendocrine tumors (NETs) demonstrated similar survival as SCC (10-year survival for regional disease of 25 and 22.3%, respectively). Ten-year survival of small cell NETs resembled AM (5.3 vs 2.5%). Age 60 years or older, sex, black race, stage, and surgery were independent predictors of survival. This study presents the largest patient series of rare anal neoplasms. NETs of the anal canal demonstrate similar survival patterns to SCC, whereas small cell NETs more closely resemble AM. Accurate histologic diagnosis is vital to determine treatment and surgical management because survival patterns can differ among rare anal neoplasms.

Distribution, fate and risk assessment of PAHs in water and sediments from an aquaculture- and shipping-impacted subtropical lake, China.

PubMed

Zeng, Qingfei; Jeppesen, Erik; Gu, Xiaohong; Mao, Zhigang; Chen, Huihui

2018-06-01

The spatial-temporal distribution of polycyclic aromatic hydrocarbons (PAHs), their source, and potential health risks were determined in overlying water and surface sediments from Chinese Lake Guchenghu, adjacent commercial mitten crab ponds and the connected Wushen Canal to assess the contamination profile of the area. The total PAHs concentrations in sediment and water were 86.7-1790 ng g -1 dry weight (dw) and 184-365 ng L -1 in summer and 184-3140 ng g -1 dw and 410-1160 ng L -1 in winter. Two- and 3-ring PAHs were the predominant compounds in water, while PAHs with 4-6 rings dominated in the sediment at both upstream and downstream sites. PAHs concentrations in water and sediment correlated significantly. Diagnostic ratios and positive matrix factorization (PMF) analyses indicated a strong influence of pyrogenic sources, principally biomass combustion and vehicle emission, on the concentrations of PAHs. The distribution, source identification, and mean effects range median quotients (mERMQ) analyses suggested that the most contaminated area was located downstream and upstream of the Wushen Canal, followed by Lake Guchenghu and a commercial crab pond area. From an ecological point of view, PAHs posed a potential risk to drinking water sources as the concentrations exceeded the guideline value of 0.05 μg L -1 . The risk posed by sediment PAHs appeared to be low except for the downstream sites, which showed a low to medium ecotoxicological risk. The total incremental lifetime cancer risks ranged between 10 -7 and 10 -5 , indicating a potential health risk for the local population when exposed to sediment from the area. Copyright © 2018 Elsevier Ltd. All rights reserved.

Assessment of ecosystem response to a temporary water level drawdown and subsequent refilling at Topock Marsh, Arizona—July 2011–October 2014

USGS Publications Warehouse

Daniels, Joan S.; Haegele, Jeanette C.

2017-01-20

Topock Marsh is a 1,637-hectare (4,045-acre) wetland adjacent to the Colorado River near Needles, California, and a main feature of Havasu National Wildlife Refuge (NWR). The U.S. Fish and Wildlife Service, in cooperation with the Bureau of Reclamation, began construction of an infrastructure improvement project in 2010 to increase the efficiency of water use and to help protect the habitats and species found within the Havasu NWR. During construction, normal water delivery from the Colorado River into Topock Marsh through the Inlet Canal was restricted, which resulted in unusually low water elevations  in 2011. The U.S. Geological Survey, commissioned by the U.S. Fish and Wildlife Service, undertook the investigation of the water quality and aquatic flora and fauna during the low water conditions. Subsequently, water elevations in the marsh returned to more normal elevations after the new concrete-lined Fire Break Canal became fully operational in January 2012.The U.S. Geological Survey made 11 field trips to the Havasu NWR between July 2011 and October 2014 to assess the effects of the temporary low water conditions and the change of inflow location (from the Inlet Canal to the Fire Break Canal) on water quality and aquatic habitat. The following conditions were monitored: water quality, sediment and plant chemistry, phytoplankton, zooplankton, aquatic macro-invertebrates, and emergent and submerged aquatic vegetation (SAV). Water-quality and biota data collected during 2013–14 were then compared with data collected during the 2011–12 low water period.Once the new Fire Break Canal became operational and Colorado River water flowed regularly into the marsh, concentrations of several water quality parameters decreased (for example, specific conductance, total dissolved solids, turbidity, chlorophyll a, and total and organic nitrogen), and phytoplankton abundance was reduced at the upstream sampling stations (TP-3, TP-2, and TP-6); the water flow pushed water with higher concentrations of these components downstream (measured at TP-8). The upstream sampling locations in 2013–14 had decreased turbidity, therefore more SAV biomass accumulated, especially in shallow areas with water depths of ≤1.0 meter (≤3.3 feet). However, the furthest downstream station had higher turbidity caused by both the suspension of autochthonous sediment and high phytoplankton density and biovolume. This higher turbidity resulted in minimal SAV growth, especially in the deeper water (>1.0 meter [>3.3 feet]). Emergent vegetation not only survived the low water conditions of 2011, but expanded its areal coverage and subsequently thrived in the higher water elevations. Overall, no immediate critically negative consequences were detected for aquatic fauna or flora that could be attributd unequivocally to the effect of low water levels. Concentrations of nutrient and trace elements in all water samples were below wildlife toxicity thresholds as established by Arizona Department of Environmental Quality. Three nonnative species were discovered shortly after the Fire Break Canal went into operation. Of the three, gizzard shad (Dorosoma cepedianum) and Eurasian watermilfoil (Myriophyllum spicatum) increased substantially in numbers from 2011–14, but quagga mussels (Dreissena bugensis) did not increase. Future monitoring will determine the long-term impact of the new flow regime

Distributed flow estimation and closed-loop control of an underwater vehicle with a multi-modal artificial lateral line.

PubMed

DeVries, Levi; Lagor, Francis D; Lei, Hong; Tan, Xiaobo; Paley, Derek A

2015-03-25

Bio-inspired sensing modalities enhance the ability of autonomous vehicles to characterize and respond to their environment. This paper concerns the lateral line of cartilaginous and bony fish, which is sensitive to fluid motion and allows fish to sense oncoming flow and the presence of walls or obstacles. The lateral line consists of two types of sensing modalities: canal neuromasts measure approximate pressure gradients, whereas superficial neuromasts measure local flow velocities. By employing an artificial lateral line, the performance of underwater sensing and navigation strategies is improved in dark, cluttered, or murky environments where traditional sensing modalities may be hindered. This paper presents estimation and control strategies enabling an airfoil-shaped unmanned underwater vehicle to assimilate measurements from a bio-inspired, multi-modal artificial lateral line and estimate flow properties for feedback control. We utilize potential flow theory to model the fluid flow past a foil in a uniform flow and in the presence of an upstream obstacle. We derive theoretically justified nonlinear estimation strategies to estimate the free stream flowspeed, angle of attack, and the relative position of an upstream obstacle. The feedback control strategy uses the estimated flow properties to execute bio-inspired behaviors including rheotaxis (the tendency of fish to orient upstream) and station-holding (the tendency of fish to position behind an upstream obstacle). A robotic prototype outfitted with a multi-modal artificial lateral line composed of ionic polymer metal composite and embedded pressure sensors experimentally demonstrates the distributed flow sensing and closed-loop control strategies.

Environmental Assessment: Lockport Approach Dike, Stage 2 Repairs, Will County, Illinois

DTIC Science & Technology

1992-03-01

May 1990 with two subsequent events, the most recent in November 1990. In the interest of safety and integrity of project operation , the U.S. Army...and operation . The dike is experiencing ongoing erosion to its canal side due to canal level fluctuations and tow prop wash at the various water levels...Impact Statement, Operation and Maintenance of a Nine-Foot Channel in the Illinols Waterway, From the Junction of the Calumet-Sag Channel and the Chicago

Dynamics of turbidity plumes in Lake Ontario. [Welland Canal and Niagara, Genesee, and Oswego Rivers

NASA Technical Reports Server (NTRS)

Pluhowski, E. J. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Large turbidity features along the 275 km south shore of Lake Ontario were analyzed using LANDSAT-1 images. The Niagara River plume, ranging from 30 to 500 sq km in area is, by far, the largest turbidity feature in the lake. Based on image tonal comparisons, turbidity in the Welland Canal is usually higher than that in any other water course discharging into the lake during the shipping season. Less turbid water enters the lake from the Port Dalhousie diversion channel and the Genesee River. Relatively clear water resulting from the deposition of suspended matter in numerous upstream lakes is discharged by the Niagara and Oswego Rivers. Plume analysis corroborates the presence of a prevailing eastward flowing longshore current along the entire south shore. Plumes resulting from beach erosion were detected in the images. Extensive areas of the south shore are subject to erosion but the most severely affected beaches are situated between Fifty Mile Point, Ontario and Thirty Mile Point, New York along the Rochester embayment, and between Sodus Bay and Nine Mile Point.

Photodynamic therapy with water-soluble phtalocyanines against bacterial biofilms in teeth root canals

NASA Astrophysics Data System (ADS)

Gergova, Raina; Georgieva, Tzvetelina; Angelov, Ivan; Mantareva, Vanya; Valkanov, Serjoga; Mitov, Ivan; Dimitrov, Slavcho

2012-06-01

The study presents the PDT with metal phthalocyanines on biofilms grown in root canals of ten representatives of the Gram-positive and the Gram-negative bacterial species and a fungus Candida albicans which cause aqute teeth infections in root canals.. The extracted human single-root teeth infected for 48 h with microorganisms in conditions to form biofilms of the above pathogens were PDT treated. The stage of biofilm formation and PDT effect of the samples of the teeth were determined by the scaning electron microscopy and with standard microbial tests. The PDT treating procedure included 10 min incubation with the respected phthalocyanine and irradiated with 660 nm Diode laser for 10 min. The most strongly antibacterial activity was achieved with zinc(II) phthalocyanine (ZnPc) against Enterococcus faecalis, Staphylococcus aureus and Moraxella catarrhalis. The other Gram-negative bacteria and Candida albicans were 10-100 times more resistant than the Gram-positive species. The Gram-negative Moraxella catarrhalis and Acinetobacter baumannii were more sensitive than the enterobacteria, but eradication of Pseudomonas aeruginosa in biofilm was insignificant. The influence of the stage of biofilm formation and the initial conditions (bacterial density, photosensitizer concentration and energy fluence of radiation) to the obtained level of inactivation of biofilms was investigated. The PDT with ZnPc photosensitizers show a powerful antimicrobial activity against the most frequent pathogens in endodontic infections and this method for inactivation of pathogens may be used with sucsses for treatment of the bacterial biofilms in the root canals.

Functional consequences of structural differences in stingray sensory systems. Part I: mechanosensory lateral line canals.

PubMed

Jordan, Laura K; Kajiura, Stephen M; Gordon, Malcolm S

2009-10-01

Short range hydrodynamic and electrosensory signals are important during final stages of prey capture in elasmobranchs (sharks, skates and rays), and may be particularly useful for dorso-ventrally flattened batoids with mouths hidden from their eyes. In stingrays, both the lateral line canal and electrosensory systems are highly modified and complex with significant differences on ventral surfaces that relate to feeding ecology. This study tests functional hypotheses based on quantified differences in sensory system morphology of three stingray species, Urobatis halleri, Myliobatis californica and Pteroplatytrygon violacea. Part I investigates the mechanosensory lateral line canal system whereas part II focuses on the electrosensory system. Stingray lateral line canals include both pored and non-pored sections and differ in branching complexity and distribution. A greater proportion of pored canals and high pore numbers were predicted to correspond to increased response to water flow. Behavioral experiments were performed to compare responses of stingrays to weak water jets mimicking signals produced by potential prey at velocities of 10-20 cm s(-1). Bat rays, M. californica, have the most complex and broadly distributed pored canal network and demonstrated both the highest response rate and greater response intensity to water jet signals. Results suggest that U. halleri and P. violacea may rely on additional sensory input, including tactile and visual cues, respectively, to initiate stronger feeding responses. These results suggest that stingray lateral line canal morphology can indicate detection capabilities through responsiveness to weak water jets.

Dissolved-Solids Load in Henrys Fork Upstream from the Confluence with Antelope Wash, Wyoming, Water Years 1970-2009

USGS Publications Warehouse

Foster, Katharine; Kenney, Terry A.

2010-01-01

Annual dissolved-solids load at the mouth of Henrys Fork was estimated by using data from U.S. Geological Survey streamflow-gaging station 09229500, Henrys Fork near Manila, Utah. The annual dissolved-solids load for water years 1970-2009 ranged from 18,300 tons in 1977 to 123,300 tons in 1983. Annual streamflows for this period ranged from 14,100 acre-feet in 1977 to 197,500 acre-feet in 1983. The 25-percent trimmed mean dissolved-solids load for water years 1970-2009 was 44,300 tons per year at Henrys Fork near Manila, Utah. Previous simulations using a SPAtially Referenced Regression On Watershed attributes (SPARROW) model for dissolved solids specific to water year 1991 conditions in the Upper Colorado River Basin predicted an annual dissolved-solids load of 25,000 tons for the Henrys Fork Basin upstream from Antelope Wash. On the basis of computed dissolved-solids load data from Henrys Fork near Manila, Utah, together with estimated annual dissolved-solids load from Antelope Wash and Peoples Canal, this prediction was adjusted to 37,200 tons. As determined by simulations with the Upper Colorado River Basin SPARROW model, approximately 56 percent (14,000 tons per year) of the dissolved-solids load at Henrys Fork upstream from Antelope Wash is associated with the 21,500 acres of irrigated agricultural lands in the upper Henrys Fork Basin.

Chemically Assisted Photocatalytic Oxidation System

NASA Technical Reports Server (NTRS)

Andino, Jean; Wu, Chang-Yu; Mazyck, David; Teixeira, Arthur A.

2009-01-01

The chemically assisted photocatalytic oxidation system (CAPOS) has been proposed for destroying microorganisms and organic chemicals that may be suspended in the air or present on surfaces of an air-handling system that ventilates an indoor environment. The CAPOS would comprise an upstream and a downstream stage that would implement a tandem combination of two partly redundant treatments. In the upstream stage, the air stream and, optionally, surfaces of the air-handling system would be treated with ozone, which would be generated from oxygen in the air by means of an electrical discharge or ultraviolet light. In the second stage, the air laden with ozone and oxidation products from the first stage would be made to flow in contact with a silica-titania photocatalyst exposed to ultraviolet light in the presence of water vapor. Hydroxyl radicals generated by the photocatalytic action would react with both carbon containing chemicals and microorganisms to eventually produce water and carbon dioxide, and ozone from the first stage would be photocatalytically degraded to O2. The net products of the two-stage treatment would be H2O, CO2, and O2.

Morphologic variations of maxillary molars palatal root and the importance of its knowledge for endodontic practice: a case series.

PubMed

Scarparo, Roberta Kochenborger; Pereira, Leticia; Moro, Diana; Grundling, Grasiela; Gomes, Maximiliano; Grecca, Fabiana Soares

2011-03-01

The present report describes and discusses root canal variations in the internal morphology of maxillary molars. Dental internal anatomy is directly related to all the technical stages of the endodontic treatment. Even though, in some situations a typical anatomical characteristics can be faced, and the professional should be able to identify them. This clinical report describes five cases with different pulpar and periapical diagnostics where the endodontic treatment was performed, in which during the treatment the unusual occurrence of two or three canals in the palatal root 'or even two distinct palatal roots' of first and second maxillary molars, were described and important details for achieving treatment success were discussed. The knowledge of tooth internal anatomy must be considered during clinical and radiographic examinations. This should be valued not only to find atypical canals but also to enable calcified canals cleaning and shaping, once they are frequently omitted during endodontic therapy. Anatomic variations can occur in any tooth, and palatal roots of maxillary first and second molars are no exception. The complexity of the root canal system and the importance of identifying its internal anatomy for planning endodontic treatment increase the chances of success.

Climate-induced trends in predator–prey synchrony differ across life-history stages of an anadromous salmonid

USGS Publications Warehouse

Bell, Donovan A.; Kovach, Ryan; Vulstek, Scott C.; Joyce, John E.; Tallmon, David A.

2017-01-01

Differential climate-induced shifts in phenology can create mismatches between predators and prey, but few studies have examined predator–prey mismatch across multiple life-history stages. We used long-term data from a warming stream with shifting salmonid migration timings to quantify intra-annual migration synchrony between predatory Dolly Varden (Salvelinus malma) and Pacific salmon prey and examined how predator–prey synchrony has been influenced by climate change. We demonstrate that Dolly Varden have become increasingly mismatched with spring downstream migrations of abundant pink salmon (Oncorhynchus gorbuscha) juveniles. However, Dolly Varden have remained matched with fall upstream migrations of spawning Pacific salmon, including coho (Oncorhynchus kisutch), sockeye (Oncorhynchus nerka), and pink salmon. Downstream predator–prey migration synchrony decreased over time and with higher temperatures, particularly with pink salmon. In contrast, upstream migration synchrony was temporally stable and increased with rising temperatures. Differing trends in Dolly Varden predator–prey synchrony may be explained by the direct use of salmon to cue upstream migration, but not downstream migration. Overall, we show that climate change can have differing impacts on predator–prey synchrony across life-history stages.

Spatiotemporal change of phosphorous speciation and concentration in stormwater in the St. Lucie Estuary watershed, South Florida.

PubMed

Li, Liguang; He, Zhenli; Li, Zhigang; Li, Suli; Wan, Yongshan; Stoffella, Peter J

2017-04-01

Phosphorous (P) concentration in stormwater runoff varies at different spatial and temporal scales. Excessive P loading from agriculture system into the St. Lucie Estuary (SLE) contributed to water quality deterioration in southern Indian River Lagoon. This study examines the spatial and temporal shifts of different P forms in runoff and storm water under different land use, water management, and rainfall conditions. Storm water samplings were conducted monthly between April 2013 and December 2014 in typical farmland and along the waterway (Canal C-24) that connects lands to the SLE. Concentrations of different P forms and related water quality variables were measured. Approximately 89% of the collected water samples contained total P (TP) concentrations exceeding the total maximum daily load (TMDL) level (0.081 mg L -1 ). Concentrations of different P forms declined from agricultural field furrows to the canal and then increased from the upstream to the downstream in the canal where urban activities dominated land use. Total dissolved P (TDP) was the predominant form of TP, followed by PO 4 -P. Speciation and concentrations of P varied with sites and sampling times, but were significantly higher in the summer months (from June to September) than in the winter. Water pH explained ∼20% of TP variation. Spatiotemporal variations of P concentrations and compositions provide a data-based guide for development of best management practices (BMPs) to minimize P export from the SLE watershed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Resolution of sensory ambiguities for gaze stabilization requires a second neural integrator

NASA Technical Reports Server (NTRS)

Green, Andrea M.; Angelaki, Dora E.

2003-01-01

The ability to simultaneously move in the world and maintain stable visual perception depends critically on the contribution of vestibulo-ocular reflexes (VORs) to gaze stabilization. It is traditionally believed that semicircular canal signals drive compensatory responses to rotational head disturbances (rotational VOR), whereas otolith signals compensate for translational movements [translational VOR (TVOR)]. However, a sensory ambiguity exists because otolith afferents are activated similarly during head translations and reorientations relative to gravity (i.e., tilts). Extra-otolith cues are, therefore, necessary to ensure that dynamic head tilts do not elicit a TVOR. To investigate how extra-otolith signals contribute, we characterized the temporal and viewing distance-dependent properties of a TVOR elicited in the absence of a lateral acceleration stimulus to the otoliths during combined translational/rotational motion. We show that, in addition to otolith signals, angular head position signals derived by integrating sensory canal information drive the TVOR. A physiological basis for these results is proposed in a model with two distinct integration steps. Upstream of the well known oculomotor velocity-to-position neural integrator, the model incorporates a separate integration element that could represent the "velocity storage integrator," whose functional role in the oculomotor system has so far remained controversial. We propose that a key functional purpose of the velocity storage network is to temporally integrate semicircular canal signals, so that they may be used to extract translation information from ambiguous otolith afferent signals in the natural and functionally relevant bandwidth of head movements.

Antibacterial Properties Associated with Chitosan Nanoparticle Treatment on Root Dentin and 2 Types of Endodontic Sealers.

PubMed

Del Carpio-Perochena, Aldo; Kishen, Anil; Shrestha, Annie; Bramante, Clovis Monteiro

2015-08-01

The aim of this study was to evaluate the efficacy of carboxymethyl chitosan (CMCS) and chitosan nanoparticles (CNps) to inactivate bacteria and prevent biofilm formation at sealer-dentin interfaces. The study was divided into 3 stages: first stage, the experiment was conducted to analyze the antibacterial properties of CMCS in different formulations against biofilms; second stage, direct-contact and membrane-restricted methods were used to evaluate the antibacterial properties of an epoxy resin (ThermaSeal Plus; Dentsply Tulsa Dental, Tulsa, OK) and calcium silicate (MTA Fillapex; Angelus SA, Londrina, PR, Brazil) based-sealers with or without CNps; and third stage, biofilm formation at the sealer dentin interfaces of root dentin treated with CMCS and filled with gutta-percha and CNp incorporated sealer were analyzed after 1- and 4-week aging periods. The samples were treated and filled as follows: (1) distilled water: unaltered sealer (control group), (2) CMCS: sealer+CNps (CMCS group), and (3) CMCS/rose bengal: sealer+CNps (CMCS/RB group). Enterococcus faecalis was used to infect all the samples. Microbiological and microscopic analyses were used to assess the antibacterial characteristics. CMCS-based treatments effectively killed bacteria adherent on root dentin (P < .05). The addition of CNps to ThermaSeal enhanced its antibacterial ability by direct-contact and membrane-restricted tests (P < .05). The CNp incorporation significantly increased the antibacterial efficacy of root canal sealers even after a 4-week aging time (P < .05). This study highlighted the ability of CMCS to disinfect root canal dentin and inhibit bacterial adhesion. CNps in root canal sealers are capable of maintaining their antibacterial activity even after prolonged aging. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Methods to quantify seepage beneath Levee 30, Miami-Dade County, Florida

USGS Publications Warehouse

Sonenshein, R.S.

2001-01-01

A two-dimensional, cross-sectional, finite-difference, ground-water flow model and a simple application of Darcy?s law were used to quantify ground-water flow (from a wetlands) beneath Levee 30 in Miami-Dade County, Florida. Geologic and geophysical data, vertical seepage data from the wetlands, canal discharge data, ground-water-level data, and surface-water-stage data collected during 1995 and 1996 were used as boundary conditions and calibration data for the ground-water flow model and as input for the analytical model. Vertical seepage data indicated that water from the wetlands infiltrated the subsurface, near Levee 30, at rates ranging from 0.033 to 0.266 foot per day when the gates at the control structures along Levee 30 canal were closed. During the same period, stage differences between the wetlands (Water Conservation Area 3B) and Levee 30 canal ranged from 0.11 to 1.27 feet. A layer of low-permeability limestone, located 7 to 10 feet below land surface, restricts vertical flow between the surface water in the wetlands and the ground water. Based on measured water-level data, ground-water flow appears to be generally horizontal, except in the direct vicinity of the canal. The increase in discharge rate along a 2-mile reach of the Levee 30 canal ranged from 9 to 30 cubic feet per second per mile and can be attributed primarily to ground-water inflow. Flow rates in Levee 30 canal were greatest when the gates at the control structures were open. The ground-water flow model data were compared with the measured ground-water heads and vertical seepage from the wetlands. Estimating the horizontal ground-water flow rate beneath Levee 30 was difficult owing to the uncertainty in the horizontal hydraulic conductivity of the main flow zone of the Biscayne aquifer. Measurements of ground-water flows into Levee 30 canal, a substantial component of the water budget, were also uncertain, which lessened the ability to validate the model results. Because of vertical flows near Levee 30 canal and a very low hydraulic gradient east of the canal, a simplified Darcian approach simulated with the ground-water flow model does not accurately estimate the horizontal ground-water flow rate. Horizontal ground-water flow rates simulated with the ground-water flow model (for a 60-foot-deep by 1-foot-wide section of the Biscayne aquifer) ranged from 150 to 450 cubic feet per day west of Levee 30 and from 15 to 170 cubic feet per day east of Levee 30 canal. Vertical seepage from the wetlands, within 500 feet of Levee 30, generally accounted for 10 to 15 percent of the total horizontal flow beneath the levee. Simulated horizontal ground-water flow was highest during the wet season and when the gates at the control structures were open.

Early irrigation systems in southeastern Arizona: the ostracode perspective

NASA Astrophysics Data System (ADS)

Palacios-Fest, Manuel R.; Mabry, Jonathan B.; Nials, Fred; Holmlund, James P.; Miksa, Elizabeth; Davis, Owen K.

2001-10-01

For the first time, the Early Agricultural Period (1200 BC-150 AD) canal irrigation in the Santa Cruz River Valley, southeastern Arizona, is documented through ostracode paleoecology. Interpretations based on ostracode paleoecology and taphonomy are supported by anthropological, sedimentological, geomorphological, and palynological information, and were used to determine the environmental history of the northern Tucson Basin during the time span represented by the sequence of canals at Las Capas (site AZ AA:12:753 ASM). We also attempt to elucidate based on archaeological artifacts if the Hohokam or a previous civilization built the canals. Between 3000 and 2400 radiocarbon years BP, at least three episodes of canal operation are defined by ostracode assemblages and pollen records. Modern (mid-late 20th century) canals supported no ostracodes, probably because of temporally brief canal operation from local wells. Three stages of water management are well defined during prehistoric canal operation. Ostracode faunal associations indicate that prehistoric peoples first operated their irrigation systems in a simple, 'opportunistic' mode (diversion of ephemeral flows following storms), and later in a complex, 'functional' mode (carefully timed diversions of perennial flows). The geomorphological reconstruction indicates that these canals had a minimum length of 1.1 km, and were possibly twice as long. The hydraulic reconstruction of these canals suggests that they had similar gradients (0.05-0.1%) to later prehistoric canals in the same valley. Discharges were also respectable. When flowing at bank-full, the largest canal provided an acre-foot of water in about 2.3 h; when flowing half-full (probably a more realistic assumption), it produced an acre-foot of water in about 8.6 h. Palynological records of the oldest canals (here identified as Features 3 and 4; 3000-2500 years BP) indicate they were used temporarily, since riparian vegetation did not grow consistently in the area. The presence of maize (Zea sp.) pollen in the canals confirms agricultural use of the canal water. However, a low percentage of maize and weed pollen suggests limited agricultural activity in this location, consistent with the lithostratigraphy, granulometry, and ostracode paleoecology. Agricultural fields were probably located downstream of this site. Ostracode assemblages show patterns consistent with the opportunistic or functional water control method, hence proving their value as indicators of human activity and environmental change. The transition from opportunistic to functional modes of canal operation indicates the increasing complexity of the social structure in the Santa Cruz Valley during the San Pedro Phase (1200-800 BC) of the Early Agricultural Period.

Apical extrusion of debris during the preparation of oval root canals: a comparative study between a full-sequence SAF system and a rotary file system supplemented by XP-endo finisher file.

PubMed

Kfir, Anda; Moza-Levi, Rotem; Herteanu, Moran; Weissman, Amir; Wigler, Ronald

2018-03-01

The purpose of this study was to assess the amount of apically extruded debris during the preparation of oval canals with either a rotary file system supplemented by the XP-endo Finisher file or a full-sequence self-adjusting file (SAF) system. Sixty mandibular incisors were randomly assigned to two groups: group A: stage 1-glide path preparation with Pre-SAF instruments. Stage 2-cleaning and shaping with SAF. Group B: stage 1-glide path preparation with ProGlider file. Stage 2-cleaning and shaping with ProTaper Next system. Stage 3-Final cleaning with XP-endo Finisher file. The debris extruded during each of the stages was collected, and the debris weights were compared between the groups and between the stages within the groups using t tests with a significance level set at P < 0.05. The complete procedure for group B resulted in significantly more extruded debris compared to group A. There was no significant difference between the stages in group A, while there was a significant difference between stage 2 and stages 1 and 3 in group B, but no significant difference between stages 1 and 3. Both instrumentation protocols resulted in extruded debris. Rotary file followed by XP-endo Finisher file extruded significantly more debris than a full-sequence SAF system. Each stage, in either procedure, had its own contribution to the extrusion of debris. Final preparation with XP-endo Finisher file contributes to the total amount of extruded debris, but the clinical relevance of the relative difference in the amount of apically extruded debris remains unclear.

Compartment-based hydrodynamics and water quality modeling of a northern Everglades wetland, Florida, USA

USGS Publications Warehouse

Wang, Hongqing; Meselhe, Ehab A.; Waldon, Michael G.; Harwell, Matthew C.; Chen, Chunfang

2012-01-01

The last remaining large remnant of softwater wetlands in the US Florida Everglades lies within the Arthur R. Marshall Loxahatchee National Wildlife Refuge. However, Refuge water quality today is impacted by pumped stormwater inflows to the eutrophic and mineral-enriched 100-km canal, which circumscribes the wetland. Optimal management is a challenge and requires scientifically based predictive tools to assess and forecast the impacts of water management on Refuge water quality. In this research, we developed a compartment-based numerical model of hydrodynamics and water quality for the Refuge. Using the numerical model, we examined the dynamics in stage, water depth, discharge from hydraulic structures along the canal, and exchange flow among canal and marsh compartments. We also investigated the transport of chloride, sulfate and total phosphorus from the canal to the marsh interior driven by hydraulic gradients as well as biological removal of sulfate and total phosphorus. The model was calibrated and validated using long-term stage and water quality data (1995-2007). Statistical analysis indicates that the model is capable of capturing the spatial (from canal to interior marsh) gradients of constituents across the Refuge. Simulations demonstrate that flow from the eutrophic and mineral-enriched canal impacts chloride and sulfate in the interior marsh. In contrast, total phosphorus in the interior marsh shows low sensitivity to intrusion and dispersive transport. We conducted a rainfall-driven scenario test in which the pumped inflow concentrations of chloride, sulfate and total phosphorus were equal to rainfall concentrations (wet deposition). This test shows that pumped inflow is the dominant factor responsible for the substantially increased chloride and sulfate concentrations in the interior marsh. Therefore, the present day Refuge should not be classified as solely a rainfall-driven or ombrotrophic wetland. The model provides an effective screening tool for studying the impacts of various water management alternatives on water quality across the Refuge, and demonstrates the practicality of similarly modeling other wetland systems. As a general rule, modeling provides one component of a multi-faceted effort to provide technical support for ecosystem management decisions.

[Subtemporal approach according to house versus Wigand in intrameatal CPA tumors type A].

PubMed

Schipper, J; Maier, W; Laszig, R

2004-10-01

The subtemporal approach is indicated in intrameatal CPA tumors type A in order to preserve hearing. The exploration of the inner auditory canal for tumor exposure varies. It reaches from a locally limited uncovering of the bony inner auditory canal to a complete removal of the surrounding bony bed with the circular skeletization (360 degrees ) according to Wigand of the 7 (th) and 8 (th) nerve. Concerning the preservation of the function of the cranial nerve as well as an avoidable hyperelevation of the temporal cerebral lobe with a possible consecutive organic brain syndrome, both approaches have often been discussed controversially. In a quality assurance analysis, we examined patients suffering from a unilateral, intrameatally limited CPA tumor type A in tumor stages 1 to 5. The functions of the 7 (th) and 8 (th) cranial nerves were assessed according to the consensus conference "Systems for reporting results in acoustic neuroma", Tokyo, November 2001, under consideration of the recommendations of the "American Academy of Otolaryngology, Head and Neck Surgery -- Committee on hearing and equilibrium guidelines for the evaluation of hearing preservation in acoustic neuroma", 1995, as well as indications for a possible organic brain syndrome. The results then were compared to current literature. 37 patients with an intrameatal confined CPA tumor after subtemporal tumor exstirpation were evaluated. In these patients, the inner auditory canal was only exposed in the area of the bony tectum (90 degrees - 120 degrees ) adjusted to the volume of the tumor, as described by House: 1 patient with tumor stage 1, 2 patients stage 2, 12 patients stage 3, 16 patients stage 4 and 6 patients with a tumor stage 5. The N. VII was anatomically preserved in 100 %. Immediately after surgery the function of N. VII was assessed in 32 % of the cases as stage I, 43 % stage II, 3 % stage IIIa, 14 % stage IIIb, 3 % stage IV, 0 % stage V, 5 % stage VI. All patients in stage VI had a restricted function of N. VII in stage II or IIIa already before surgery. N. VIII could be preserved anatomically in 78 % of the cases. 1 to 6 months postoperatively the hearing was at stage A in 10 % of the cases, at 25 % in stage B, 33 % in stage C, 16 % in stage D, 5 % in stage E and 11 % in stage F. One patient demonstrated signs of a possible organic brain syndrome postoperatively even after 12 months of latency (headache, unsteady walking, attention disorders). When comparing own data with the clinical results from literature, no differences can be found concerning the function of the 7 (th) and 8 (th) cranial nerves. There are no data concerning the incidence of a potential organic brain syndrome. The advantage of the House method is a noticeably reduced drilling time as well as possibly a reduced elevation of the temporal cerebral lobes. The Wigand method, however, allows a better overview and is needed for extrameatally growing tumors anyway.

Quantifying seepage using heat as a tracer in selected irrigation canals, Walker River Basin, Nevada, 2012 and 2013

USGS Publications Warehouse

Naranjo, Ramon C.; Smith, David W.

2016-11-16

The Walker River is an important source of water for western Nevada. The river provides water for agriculture and recharge to local aquifers used by several communities. Farmers began diverting water from the Walker River in the 1860s to support growing agricultural development. Over time, the reduced inflows into Walker Lake from upstream reservoirs and diversions have resulted in 170 feet of lake level decline and increased dissolved-solids concentrations to levels that threaten aquatic ecosystems, including survival of Lahonton cutthroat trout, a native species listed in the Endangered Species Act. Investigations of the water-budget components in the Walker River Basin have revealed uncertainty in the recharge to aquifers from irrigation canals. To address this need, the U.S. Geological Survey conducted an extensive field study from March 2012 through October 2013 to quantify seepage losses in selected canals in the Smith Valley, Mason Valley, and Walker Lake Valley irrigation areas.The seepage rates estimated for the 2012 and 2013 irrigation seasons in the Smith Valley transect sites (Saroni and Plymouth canals) ranged between 0.01 to 2.5 feet per day (ft/d) (0.01 to 0.68 cubic feet per second per mile [ft3/s-mi]). From 2012 to 2013, the average number of days the canals had flowing water decreased from 190 to 125 due to drier climate and lack of water available for diversion from the Walker River. The nearly 50-percent reductions in volumetric loss rates between 2012 and 2013 were associated with less than average diversions into canals from the Walker River and reductions in infiltration rates following routine canal maintenance.Models developed for the Saroni canal in 2012 were recalibrated in 2013 to evaluate changes in seepage as a result of siltation. Just prior to the 2012 irrigation season, nearly the entire length of the canal was cleared of vegetation and debris to improve flow conveyance. In 2013, following the first year of maintenance, a 90-percent reduction in seepage was observed at one of the transect sites. The removal of sediment-clogged layers during canal maintenance may have more profound effects on seepage rates beyond what was observed at the transect sites. The seepage rates for the Saroni canal in 2012 ranged from 0.02 to 1.6 ft/d (0.03 to 0.4 ft3/s-mi). The total seepage loss in the Saroni canal for the 2012 and 2013 irrigation seasons was estimated to be 1,100 and 590 acre-feet (acre-ft), respectively.Seepage rates on the Plymouth canal in Smith Valley in 2012 were among the lowest, ranging from 0.01 to 0.2 ft/d (0.01 to 0.1 ft3/s-mi). In 2013, the seepage rate on the Plymouth canal was similar to 2012; however, the volumetric loss was reduced by 50 percent due to the 50-percent reduction in number of canal flow days. Lower rates of seepage on the Plymouth canal for the 2012 and 2013 irrigation seasons were estimated to be 210 and 130 acre-ft, respectively.The seepage rates estimated for the 2012 and 2013 irrigation seasons in the Mason Valley transect sites (Fox, Mickey, and Campbell ditches) ranged from 0.1 to 3.3 ft/d (0.2 to 1.3 ft3/s-mi). The influence of water-table declines on seepage was observed at the Mickey and Campbell ditches. In 2012, the estimated seepage on the Mickey ditch was 1.6 ft/d during a period when the water-table altitude was at or above the canal altitude. Following extensive declines in the water table, the hydraulic gradient increased between the canal and the shallow aquifer, thereby increasing the seepage rates to 3.2 ft/d in 2013. During the period of hydraulic disconnection, seepage rates increased to 9.5 ft/d during intermittent periods of canal flow. For the Mickey ditch, the seepage loss in 2013 was 1.5 times the rate estimated in 2012 despite the canal having 45 days less flow. Similarly, the Campbell ditch seepage loss increased slightly from 660 to 700 acre-ft, a factor of 1.1, with 49 days less flow. The seepage loss for the Fox ditch did not exhibit significant year to year variability. The annual seepage loss estimated for 2012 and 2013 in the Fox ditch was 2,100 and 2,200 acre-ft, respectively.The seepage rates estimated for the 2013 irrigation season in the Walker Lake Valley transect sites (Schurz Lateral Canals 1A and 2A, and Canal 2) ranged from 0.7 to 0.9 ft/d (0.4 to 1.3 ft3/s-mi). In Walker Lake Valley, diversions into Lateral Canals 1A and 2A during the 2013 irrigation season were highly intermittent, a characteristic common of lateral diversions. The annual estimated seepage loss in Walker Lake Valley ranged between 50 and 725 acre-ft among the transect sites.

Passive control of discrete-frequency tones generated by coupled detuned cascades

NASA Astrophysics Data System (ADS)

Sawyer, S.; Fleeter, S.

2003-07-01

Discrete-frequency tones generated by rotor-stator interactions are of particular concern in the design of fans and compressors. Classical theory considers an isolated flat-plate cascade of identical uniformly spaced airfoils. The current analysis extends this tuned isolated cascade theory to consider coupled aerodynamically detuned cascades where aerodynamic detuning is accomplished by changing the chord of alternate rotor blades and stator vanes. In a coupled cascade analysis, the configuration of the rotor influences the downstream acoustic response of the stator, and the stator configuration influences the upstream acoustic response of the rotor. This coupled detuned cascade unsteady aerodynamic model is first applied to a baseline tuned stage. This baseline stage is then aerodynamically detuned by replacing alternate rotor blades and stator vanes with decreased chord airfoils. The nominal aerodynamically detuned stage configuration is then optimized, with the stage acoustic response decreased 13 dB upstream and 1 dB downstream at the design operating condition. A reduction in the acoustic response of the optimized aerodynamically detuned stage is then demonstrated over a range of operating conditions.

[A case of a geriatric patient with stage IV anal canal cancer showing complete response to chemoradiation therapy].

PubMed

Kuroda, Masatoshi; Hirai, Ryuji; Ikeda, Eiji; Tsuji, Hisashi; Takagi, Shoji; Yamano, Toshihisa; Yoshitomi, Seiji

2012-11-01

We present a case in which chemoradiation therapy was effective in a geriatric patient with Stage IV anal canal cancer. The patient is an 81-year-old woman who complained of proctorrhagia and anal pain. She was referred to us by her family doctor who suspected rectal cancer. Tumors as large as 6.5 cm in diameter mainly on the right side of the rectum as well as 2 palpable enlarged lymph nodes on the right inguinal area, were found during the initial physical examination. Squamous cell carcinoma was elevated to 16 ng/mL. A CT scan revealed that irregularly shaped masses as large as 7 cm in diameter were externally exposed on the right side of the rectum along with enlarged lymph nodes on the right inguinal area and metastasis at S7 lesion in the liver. Squamous cell carcinoma was diagnosed from biopsy results. Due to her age, the chemotherapy regimen was S-1+CDDP with radiation therapy and 4-port irradiation (50.4 Gy) of the primary tumor, interior of the pelvis, and inguinal lymph nodes. Partial response was observed upon completion of treatment, and complete response was obtained after 6 months. She is currently an outpatient taking S-1: 60 mg/day orally. There is no indication of cancer recurrence after 1 year and 3 months, and she continues to visit an outpatient clinic for regular follow-ups. These results demonstrate the effectiveness of chemoradiation therapy for geriatric patients with Stage IV anal canal cancer.

A feasibility and optimization study to determine cooling time and burnup of advanced test reactor fuels using a nondestructive technique

NASA Astrophysics Data System (ADS)

Navarro, Jorge

The goal of this study presented is to determine the best available nondestructive technique necessary to collect validation data as well as to determine burnup and cooling time of the fuel elements on-site at the Advanced Test Reactor (ATR) canal. This study makes a recommendation of the viability of implementing a permanent fuel scanning system at the ATR canal and leads to the full design of a permanent fuel scan system. The study consisted at first in determining if it was possible and which equipment was necessary to collect useful spectra from ATR fuel elements at the canal adjacent to the reactor. Once it was establish that useful spectra can be obtained at the ATR canal, the next step was to determine which detector and which configuration was better suited to predict burnup and cooling time of fuel elements nondestructively. Three different detectors of High Purity Germanium (HPGe), Lanthanum Bromide (LaBr3), and High Pressure Xenon (HPXe) in two system configurations of above and below the water pool were used during the study. The data collected and analyzed were used to create burnup and cooling time calibration prediction curves for ATR fuel. The next stage of the study was to determine which of the three detectors tested was better suited for the permanent system. From spectra taken and the calibration curves obtained, it was determined that although the HPGe detector yielded better results, a detector that could better withstand the harsh environment of the ATR canal was needed. The in-situ nature of the measurements required a rugged fuel scanning system, low in maintenance and easy to control system. Based on the ATR canal feasibility measurements and calibration results, it was determined that the LaBr3 detector was the best alternative for canal in-situ measurements; however, in order to enhance the quality of the spectra collected using this scintillator, a deconvolution method was developed. Following the development of the deconvolution method for ATR applications, the technique was tested using one-isotope, multi-isotope, and fuel simulated sources. Burnup calibrations were perfomed using convoluted and deconvoluted data. The calibrations results showed burnup prediction by this method improves using deconvolution. The final stage of the deconvolution method development was to perform an irradiation experiment in order to create a surrogate fuel source to test the deconvolution method using experimental data. A conceptual design of the fuel scan system is path forward using the rugged LaBr 3 detector in an above the water configuration and deconvolution algorithms.

Origins and delineation of saltwater intrusion in the Biscayne aquifer and changes in the distribution of saltwater in Miami-Dade County, Florida

USGS Publications Warehouse

Prinos, Scott T.; Wacker, Michael A.; Cunningham, Kevin J.; Fitterman, David V.

2014-01-01

Intrusion of saltwater into parts of the shallow karst Biscayne aquifer is a major concern for the 2.5 million residents of Miami-Dade County that rely on this aquifer as their primary drinking water supply. Saltwater intrusion of this aquifer began when the Everglades were drained to provide dry land for urban development and agriculture. The reduction in water levels caused by this drainage, combined with periodic droughts, allowed saltwater to flow inland along the base of the aquifer and to seep directly into the aquifer from the canals. The approximate inland extent of saltwater was last mapped in 1995. An examination of the inland extent of saltwater and the sources of saltwater in the aquifer was completed during 2008–2011 by using (1) all available salinity information, (2) time-series electromagnetic induction log datasets from 35 wells, (3) time-domain electromagnetic soundings collected at 79 locations, (4) a helicopter electromagnetic survey done during 2001 that was processed, calibrated, and published during the study, (5) cores and geophysical logs collected from 8 sites for stratigraphic analysis, (6) 8 new water-quality monitoring wells, and (7) analyses of 69 geochemical samples. The results of the study indicate that as of 2011 approximately 1,200 square kilometers (km2) of the mainland part of the Biscayne aquifer were intruded by saltwater. The saltwater front was mapped farther inland than it was in 1995 in eight areas totaling about 24.1 km2. In many of these areas, analyses indicated that saltwater had encroached along the base of the aquifer. The saltwater front was mapped closer to the coast than it was in 1995 in four areas totaling approximately 6.2 km2. The changes in the mapped extent of saltwater resulted from improved spatial information, actual movement of the saltwater front, or a combination of both. Salinity monitoring in some of the canals in Miami-Dade County between 1988 and 2010 indicated influxes of saltwater, with maximum salinities ranging from 1.4 to 32 practical salinity units (PSU) upstream of the salinity control structures. Time-series electromagnetic induction log data from monitoring wells G–3601, G–3608, and G–3701, located adjacent to the Biscayne, Snapper Creek, and Black Creek Canals, respectively, and upstream of the salinity control structures, indicated shallow influxes of conductive water in the aquifer that likely resulted from leakage of brackish water or saltwater from these canals. The determination that saltwater influxes were recent is supported by the similarity in the oxygen and hydrogen stable isotope composition in samples from the Snapper Creek Canal, 1.6 kilometers (km) inland of a salinity control structure, and in samples from well G–3608, which is adjacent to the canal, as well as by the relative ages of the water sampled from well G–3608 and other wells open to the aquifer below the saltwater interface. Historical and recent salinity information from the Card Sound Road Canal, monitoring well FKS8 located adjacent to the canal, and the 2001 helicopter electromagnetic survey indicated that saltwater may occasionally leak from this canal as far inland as 15 km. This leakage may be prevented or reduced by a salinity control structure that was installed in May 2010. Saltwater also may have leaked from the Princeton Canal. Results of geochemical sampling and analysis indicate a close correspondence between droughts and saltwater intrusion. Tritium/helium-3 apparent (piston-flow) ages determined from samples of saltwater with chloride concentrations of about 1,000 milligrams per liter (mg/L) or greater generally corresponded to a period during which droughts were frequent. Comparison of average daily air temperatures in Miami, Florida, with estimates of recharge temperatures determined from the dissolved gas composition in water samples indicated that saltwater likely entered the aquifer in April or early May when water levels are typically at their lowest during the year. Conversely, most of the samples of freshwater with chloride concentrations less than about 1,000 mg/L indicate recharge temperatures corresponding to air temperatures in mid to late May when rainfall and water levels in the aquifer increase, and the piston-flow ages of these samples correspond to wet years. The piston-flow ages of freshwater samples generally were younger than ages of samples of saltwater. Saltwater samples that were depleted in boron, magnesium, potassium, sodium, and sulfate, and enriched in calcium relative to the concentrations theoretically produced by freshwater/seawater mixing, generally were found to be associated with areas where saltwater had recently intruded. The calcium to (bicarbonate + sulfate) molar ratios (Ca/(HCO3+SO4)) of these samples generally were greater than 1. Saltwater samples from some of the monitoring wells, however, indicated little or no enrichment or depletion of these ions relative to the theoretical freshwater/seawater mixing line, and the Ca/(HCO3+SO4) molar ratios of these samples generally were less than 1. Results indicated that aquifer materials are approaching equilibrium with seawater at these well locations.

Dams and Intergovernmental Transfers

NASA Astrophysics Data System (ADS)

Bao, X.

2012-12-01

Gainers and Losers are always associated with large scale hydrological infrastructure construction, such as dams, canals and water treatment facilities. Since most of these projects are public services and public goods, Some of these uneven impacts cannot fully be solved by markets. This paper tried to explore whether the governments are paying any effort to balance the uneven distributional impacts caused by dam construction or not. It showed that dam construction brought an average 2% decrease in per capita tax revenue in the upstream counties, a 30% increase in the dam-location counties and an insignificant increase in downstream counties. Similar distributional impacts were observed for other outcome variables. like rural income and agricultural crop yields, though the impacts differ across different crops. The paper also found some balancing efforts from inter-governmental transfers to reduce the unevenly distributed impacts caused by dam construction. However, overall the inter-governmental fiscal transfer efforts were not large enough to fully correct those uneven distributions, reflected from a 2% decrease of per capita GDP in upstream counties and increase of per capita GDP in local and downstream counties. This paper may shed some lights on the governmental considerations in the decision making process for large hydrological infrastructures.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jager, Yetta; Forsythe, Patrick S.; McLaughlin, Robert L.

The majority of large North American rivers are fragmented by dams that interrupt migrations of wide-ranging fishes like sturgeons. Reconnecting habitat is viewed as an important means of protecting sturgeon species in U.S. rivers because these species have lost between 5% and 60% of their historical ranges. Unfortunately, facilities designed to pass other fishes have rarely worked well for sturgeons. The most successful passage facilities were sized appropriately for sturgeons and accommodated bottom-oriented species. For upstream passage, facilities with large entrances, full-depth guidance systems, large lifts, or wide fishways without obstructions or tight turns worked well. However, facilitating upstream migrationmore » is only half the battle. Broader recovery for linked sturgeon populations requires safe round-trip passage involving multiple dams. The most successful downstream passage facilities included nature-like fishways, large canal bypasses, and bottom-draw sluice gates. We outline an adaptive approach to implementing passage that begins with temporary programs and structures and monitors success both at the scale of individual fish at individual dams and the scale of metapopulations in a river basin. The challenge will be to learn from past efforts and reconnect North American sturgeon populations in a way that promotes range expansion and facilitates population recovery.« less

Identifying wells downstream from Laguna Dam that yield water that will be replaced by water from the Colorado River, Arizona and California

USGS Publications Warehouse

Owen-Joyce, Sandra J.

2000-01-01

This report summarizes a comprehensive study and development of the method documented in Owen-Joyce and others (2000). That report and one for the area upstream from Laguna Dam (Wilson and Owen-Joyce, 1994) document the accounting-surface method to identify wells that yield water that will be replaced by water from the Colorado River. Downstream from Laguna Dam, the Colorado River is the source for nearly all recharge to the river aquifer. The complex surface-water and ground-water system that exists in the area is, in part, the result of more than 100 years of water-resources development. Agriculture is the principal economy and is possible only with irrigation. The construction and operation of canals provides the means to divert and distribute Colorado River water to irrigate agricultural lands on the flood plains and mesas along the Colorado and Gila Rivers, in Imperial and Coachella Valleys, and in the area upstream from Dome along the Gila River. Water is withdrawn from wells for irrigation, dewatering, and domestic use. The area downstream from Laguna Dam borders additional areas of agricultural development in Mexico where Colorado River water also is diverted for irrigation.

Reconnecting fragmented sturgeon populations in North American rivers

USGS Publications Warehouse

Jager, Henriette; Parsley, Michael J.; Cech, Joseph J. Jr.; McLaughlin, R.L.; Forsythe, Patrick S.; Elliott, Robert S.

2016-01-01

The majority of large North American rivers are fragmented by dams that interrupt migrations of wide-ranging fishes like sturgeons. Reconnecting habitat is viewed as an important means of protecting sturgeon species in U.S. rivers because these species have lost between 5% and 60% of their historical ranges. Unfortunately, facilities designed to pass other fishes have rarely worked well for sturgeons. The most successful passage facilities were sized appropriately for sturgeons and accommodated bottom-oriented species. For upstream passage, facilities with large entrances, full-depth guidance systems, large lifts, or wide fishways without obstructions or tight turns worked well. However, facilitating upstream migration is only half the battle. Broader recovery for linked sturgeon populations requires safe “round-trip” passage involving multiple dams. The most successful downstream passage facilities included nature-like fishways, large canal bypasses, and bottom-draw sluice gates. We outline an adaptive approach to implementing passage that begins with temporary programs and structures and monitors success both at the scale of individual fish at individual dams and the scale of metapopulations in a river basin. The challenge will be to learn from past efforts and reconnect North American sturgeon populations in a way that promotes range expansion and facilitates population recovery.

Tumor Stage-Related Role of Radiotherapy in Patients with an External Auditory Canal and Middle Ear Carcinoma.

PubMed

Choi, Jinhyun; Kim, Se-Heon; Koh, Yoon Woo; Choi, Eun Chang; Lee, Chang Geol; Keum, Ki Chang

2017-01-01

The purpose of this study was to evaluate the clinical outcomes of patients treated with radiotherapy (RT) for a carcinoma of the external auditory canal (EAC) and middle ear. The records of 32 patients who received RT from 1990 to 2013 were reviewed retrospectively. The Pittsburgh classification was used to stage all the cancers (early stage, T1/T2 [n=12]; advanced stage, T3/T4 or N positive [n=20]). Twenty-one patients (65.6%) were treated with postoperative RT and 11 patients (34.4%) were treated with definitive RT. The median radiation doses for postoperative and definitive RT were 60 Gy and 64.8 Gy, respectively. Chemotherapy was administered to seven patients (21.9%). The 5-year overall survival and disease-free survival rates for all patients were 57% and 52%, respectively. The disease control rates for the patients with early stage versus advanced stage carcinomawere 55.6% (5/9) and 50% (6/12) in the postoperative RT group and 66.7% (2/3) and 37.5% (3/8) in the definitive RT group, respectively. Overall, 15 cases (14 patients, 46.7%) experienced treatment failure; these failures were classified as local in four cases, regional in one case, and distant in 10 cases. The median follow-up period after RT was 51 months (range, 7 to 286 months). Patients with early stage carcinoma achieved better outcomes when definitive RT was used. Advanced stage carcinoma patients experienced better outcomes with postoperative RT. The high rate of distant failure after RT, with or without surgery, reflected the lack of a consensus regarding the best therapeutic approach for treating carcinoma of the EAC and middle ear.

Broadband Noise of Fans - With Unsteady Coupling Theory to Account for Rotor and Stator Reflection/Transmission Effects

NASA Technical Reports Server (NTRS)

Hanson, Donald B.

2001-01-01

This report examines the effects on broadband noise generation of unsteady coupling between a rotor and stator in the fan stage of a turbofan engine. Whereas previous acoustic analyses treated the blade rows as isolated cascades, the present work accounts for reflection and transmission effects at both blade rows by tracking the mode and frequency scattering of pressure and vortical waves. The fan stage is modeled in rectilinear geometry to take advantage of a previously existing unsteady cascade theory for 3D perturbation waves and thereby use a realistic 3D turbulence spectrum. In the analysis, it was found that the set of participating modes divides itself naturally into "independent mode subsets" that couple only among themselves and not to the other such subsets. This principle is the basis for the analysis and considerably reduces computational effort. It also provides a simple, accurate scheme for modal averaging for further efficiency. Computed results for a coupled fan stage are compared with calculations for isolated blade rows. It is found that coupling increases downstream noise by 2 to 4 dB. Upstream noise is lower for isolated cascades and is further reduced by including coupling effects. In comparison with test data, the increase in the upstream/downstream differential indicates that broadband noise from turbulent inflow at the stator dominates downstream noise but is not a significant contributor to upstream noise.

Predictors of Nonadherence to NCCN Guideline Recommendations for the Management of Stage I Anal Canal Cancer.

PubMed

Kole, Adam J; Stahl, John M; Park, Henry S; Khan, Sajid A; Johung, Kimberly L

2017-03-01

Background: Definitive chemoradiotherapy (CRT) is recommended by the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Anal Carcinoma for all patients with stage I anal canal cancer. Because these patients were not well represented in clinical trials establishing CRT as standard therapy, it is unclear whether NCCN recommendations are being closely followed for stage I disease. This study identified factors that predict for NCCN Guideline-concordant versus NCCN Guideline-discordant care. Methods: Using the National Cancer Data Base, we identified patients diagnosed with anal canal carcinoma from 2004 to 2012 who received concurrent CRT (radiotherapy [RT] 45.0-59.4 Gy with multiagent chemotherapy), RT alone (45.0-59.4 Gy), or surgical procedure alone (local tumor destruction, tumor excision, or abdominoperineal resection). Demographic and clinicopathologic factors were analyzed using the chi-square test and logistic regression modeling. Results: A total of 1,082 patients with histologically confirmed stage I anal cancer were identified, among whom 665 (61.5%) received CRT, 52 (4.8%) received RT alone, and 365 (33.7%) received only a surgical procedure. Primary analyses were restricted to patients receiving CRT or excision alone, as these were most common. Multivariable analysis identified factors independently associated with reduced odds of CRT receipt: low versus intermediate/high tumor grade (adjusted odds ratio [AOR], 0.21; 95% CI, 0.14-0.29; P <.001), tumor size <1 cm vs 1 to 2 cm (AOR, 0.24; 95% CI, 0.17-0.35; P <.001), age ≥70 versus 50 to 69 years (AOR, 0.36; 95% CI, 0.24-0.54; P <.001), male sex (AOR, 0.63; 95% CI, 0.45-0.90; P =.009), and treatment at an academic versus a non-academic facility (AOR, 0.58; 95% CI, 0.41-0.81; P =.002). Conclusions: Despite the NCCN recommendation of CRT for stage I anal cancer, at least one-third of patients appear to be receiving guideline-discordant management. Excision alone is more common for patients who are elderly, are male, have small or low-grade tumors, or were evaluated at academic facilities. Copyright © 2017 by the National Comprehensive Cancer Network.

Investigation on centrifugal impeller in an axial-radial combined compressor with inlet distortion

NASA Astrophysics Data System (ADS)

Li, Du; Yang, Ce; Zhao, Ben; Zhou, Mi; Qi, Mingxu; Zhang, Jizhong

2011-12-01

Assembling an axial rotor and a stator at centrifugal compressor upstream to build an axial-radial combined compressor could achieve high pressure ratio and efficiency by appropriate size augment. Then upstream potential flow and wake effect appear at centrifugal impeller inlet. In this paper, the axial-radial compressor is unsteadily simulated by three-dimensional Reynolds averaged Navier-Stokes equations with uniform and circumferential distorted total pressure inlet condition to investigate upstream effect on radial rotor. The results show that span-wise nonuniform total pressure distribution is generated and radial and circumferential combined distortion is formed at centrifugal rotor inlet. The upstream stator wake deflects to rotor rotation direction and decreases with blade span increases. Circumferential distortion causes different separated flow formations at different pitch positions. The tip leakage vortex is suppressed in centrifugal blade passages. Under distorted inlet condition, flow direction of centrifugal impeller leading edge upstream varies evidently near hub and shroud but varies slightly at mid-span. In addition, compressor stage inlet distortion produces remarkable effect on blade loading of centrifugal blade both along chordwise and pitchwise.

Two-stage removal of an impacted foreign body with an epoxied anchor.

PubMed

Isaacson, Glenn

2003-09-01

A stone impacted in a child's external auditory canal had defied all conventional means of removal. It was extracted successfully after attachment of a specially formed metal anchor with epoxy glue. The technique of and rationale for this approach are discussed.

Temperature and water-quality conditions of the Patuxent River estuary, Maryland, January 1966 through December 1967

USGS Publications Warehouse

Cory, Robert L.; Nauman, Jon W.

1970-01-01

The effect of power plant cooling water in raising natural water temperatures at a location near the power plant on the Patuxent River estuary is clearly evident from thermograph records. Surface temperature at a station 333 m (1,000 ft) downstream from the discharge canal was raised an average of about 4 C, and at times by as much as 8 C. Temperature rises were greatest during the winter. Infrared imagery showed that elevated surface temperatures could be detected about 5.5 km (3 nautical miles) upstream at flood tide. Temperature profiles obtained from airborne radiation equipment revealed a complicated surface temperature pattern and also showed the effects of density differences and wind action on the steam-electric station (S.E.S.) effluent plume. Mean annual salinity for a 5-year period (1963–1967) was highest in 1966, about 12.3 ‰, and lowest in 1967, about 9.9‰. Dissolved oxygen values for 1966–1967 ranged from 3.2 to 15.6 mg/l, and saturation ranged from 55 to 152%. Turbidity levels were inversely related to salinity, with the highest annual, mean of 28 JCU (Jackson Candle Units) occurring in 1967, the lowest salinity year. The extreme tide range was 2.1 m (6.7 ft); mean water levels at the Patuxent Bridge were highest in summer and lowest in winter. Water stages are more affected by wind speed and direction than by flow in the river.

LH2 pump component development testing in the electric pump room at test cell C inducer no. 1

NASA Technical Reports Server (NTRS)

Andrews, F. X.; Brunner, J. J.; Kirk, K. G.; Mathews, J. P.; Nishioka, T.

1972-01-01

The characteristics of a turbine pump for use with the nuclear engine for rocket vehicles are discussed. It was determined that the pump will be a two stage centrifugal pump with both stages having backswept impellers and an inducer upstream of the first stage impeller. The test program provided demonstration of the ability of the selected design to meet the imposed requirements.

Entrainment, retention, and transport of freely swimming fish in junction gaps between commercial barges operating on the Illinois Waterway

USGS Publications Warehouse

Davis, Jeremiah J.; Jackson, P. Ryan; Engel, Frank; LeRoy, Jessica Z.; Neeley, Rebecca N.; Finney, Samuel T.; Murphy, Elizabeth A.

2016-01-01

Large Electric Dispersal Barriers were constructed in the Chicago Sanitary and Ship Canal (CSSC) to prevent the transfer of invasive fish species between the Mississippi River Basin and the Great Lakes Basin while simultaneously allowing the passage of commercial barge traffic. We investigated the potential for entrainment, retention, and transport of freely swimming fish within large gaps (> 50 m3) created at junction points between barges. Modified mark and capture trials were employed to assess fish entrainment, retention, and transport by barge tows. A multi-beam sonar system enabled estimation of fish abundance within barge junction gaps. Barges were also instrumented with acoustic Doppler velocity meters to map the velocity distribution in the water surrounding the barge and in the gap formed at the junction of two barges. Results indicate that the water inside the gap can move upstream with a barge tow at speeds near the barge tow travel speed. Water within 1 m to the side of the barge junction gaps was observed to move upstream with the barge tow. Observed transverse and vertical water velocities suggest pathways by which fish may potentially be entrained into barge junction gaps. Results of mark and capture trials provide direct evidence that small fish can become entrained by barges, retained within junction gaps, and transported over distances of at least 15.5 km. Fish entrained within the barge junction gap were retained in that space as the barge tow transited through locks and the Electric Dispersal Barriers, which would be expected to impede fish movement upstream.

A computational fluid dynamics modeling study of guide walls for downstream fish passage

USGS Publications Warehouse

Mulligan, Kevin; Towler, Brett; Haro, Alexander J.; Ahlfeld, David P.

2017-01-01

A partial-depth, impermeable guidance structure (or guide wall) for downstream fish passage is typically constructed as a series of panels attached to a floating boom and anchored across a water body (e.g. river channel, reservoir, or power canal). The downstream terminus of the wall is generally located nearby to a fish bypass structure. If guidance is successful, the fish will avoid entrainment in a dangerous intake structure (i.e. turbine intakes) while passing from the headpond to the tailwater of a hydroelectric facility through a safer passage route (i.e. the bypass). The goal of this study is to determine the combination of guide wall design parameters that will most likely increase the chance of surface-oriented fish being successfully guided to the bypass. To evaluate the flow field immediately upstream of a guide wall, a parameterized computational fluid dynamics model of an idealized power canal was constructed in © ANSYS Fluent v 14.5 (ANSYS Inc., 2012). The design parameters investigated were the angle and depth of the guide wall and the average approach velocity in the power canal. Results call attention to the importance of the downward to sweeping flow ratio and demonstrate how a change in guide wall depth and angle can affect this important hydraulic cue to out-migrating fish. The key findings indicate that a guide wall set at a small angle (15° is the minimum in this study) and deep enough such that sweeping flow dominant conditions prevail within the expected vertical distribution of fish approaching the structure will produce hydraulic conditions that are more likely to result in effective passage.

Adaptive Management of Environmental Flows: Using Irrigation Infrastructure to Deliver Environmental Benefits During a Large Hypoxic Blackwater Event in the Southern Murray-Darling Basin, Australia

NASA Astrophysics Data System (ADS)

Watts, Robyn J.; Kopf, R. Keller; McCasker, Nicole; Howitt, Julia A.; Conallin, John; Wooden, Ian; Baumgartner, Lee

2018-03-01

Widespread flooding in south-eastern Australia in 2010 resulted in a hypoxic (low dissolved oxygen, DO) blackwater (high dissolved carbon) event affecting 1800 kilometres of the Murray-Darling Basin. There was concern that prolonged low DO would result in death of aquatic biota. Australian federal and state governments and local stakeholders collaborated to create refuge areas by releasing water with higher DO from irrigation canals via regulating structures (known as `irrigation canal escapes') into rivers in the Edward-Wakool system. To determine if these environmental flows resulted in good environmental outcomes in rivers affected by hypoxic blackwater, we evaluated (1) water chemistry data collected before, during and after the intervention, from river reaches upstream and downstream of the three irrigation canal escapes used to deliver the environmental flows, (2) fish assemblage surveys undertaken before and after the blackwater event, and (3) reports of fish kills from fisheries officers and local citizens. The environmental flows had positive outcomes; mean DO increased by 1-2 mg L-1 for at least 40 km downstream of two escapes, and there were fewer days when DO was below the sub-lethal threshold of 4 mg L-1 and the lethal threshold of 2 mg L-1 at which fish are known to become stressed or die, respectively. There were no fish deaths in reaches receiving environmental flows, whereas fish deaths were reported elsewhere throughout the system. This study demonstrates that adaptive management of environmental flows can occur through collaboration and the timely provision of monitoring results and local knowledge.

Streamflow and Endangered Species Habitat in the Lower Isleta Reach of the Middle Rio Grande

USGS Publications Warehouse

Bovee, Ken D.; Waddle, Terry J.; Spears, J. Mark

2008-01-01

San Acacia Dam is located in a reach of the Rio Grande that has been designated as critical habitat for two endangered species, the Rio Grande silvery minnow (Hybognathus amarus) and the southwestern willow flycatcher (Empidonax traillii extimus). Under present operations, the Rio Grande upstream from the dam is used to convey irrigation water to the Socorro main canal at San Acacia Dam. In order to increase operational flexibility and improve irrigation delivery efficiency, the 'Bernardo Siphon' has been proposed to intercept up to 150 cubic feet per second from the Lower San Juan Riverside Drain on the east side of the Rio Grande and transport it under the river into a drainage canal on the west side. Irrigation deliveries to the Socorro main canal would be conveyed by way of the drainage canal rather than the Rio Grande. The objective of this study was to provide the Bureau of Reclamation (BOR) and other stakeholders with a tool to evaluate the effects of different operational modes of the Bernardo siphon on habitat for H. amarus and E. t. extimus in this section of river. We used a two-dimensional hydraulic simulation model to simulate hydraulic conditions for a range of discharges at three study sites in the Rio Grande between the proposed siphon location and San Acacia Dam. Suitable habitat characteristics were defined for H. amarus by consensus of a panel of experts and for E. t. extimus on the basis of a study conducted in 2003 by BOR. Habitat suitability maps for each targeted life stage and simulated discharge were constructed using a Geographic Information System (ArcGIS) and the results compiled into tables relating discharge to areas of suitable habitat. A separate analysis was conducted to calculate an index of connectivity among habitat patches at low flows. A hydrologic model was constructed to synthesize flows, by reach, without the siphon, which was used as a baseline for comparison with similarly-synthesized discharges with the siphon under different operating rules. Results from the hydrologic time series were combined with the discharge-habitat relations to develop habitat time series models, statistics, and scoring metrics for comparisons of alternative rules of operation for the Bernardo siphon. Suitable habitat for H. amarus was defined as areas having suitable hydraulic conditions alone and as areas having suitable hydraulics in association with large woody debris. Suitable hydraulic habitat for adults was maximized at discharges between 40 and 80 cubic feet per second, and declined rapidly at discharges larger than 150 cubic feet per second. When large woody debris was included in the definition of suitable habitat, discharges between 40 and 200 cubic feet per second provided maximum suitable habitat for adults. Juvenile hydraulic habitat was maximized at discharges between 20 and 80 cubic feet per second, and hydraulic habitat associated with large woody debris was largest at flows between 40 and 150 cubic feet per second. Nesting habitat area for E. t. extimus increased monotonically at discharges larger than 5 ft3/s, but decreased rapidly below that flow.

A feasibility and optimization study to determine cooling time and burnup of advanced test reactor fuels using a nondestructive technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Navarro, Jorge

2013-12-01

The goal of this study presented is to determine the best available non-destructive technique necessary to collect validation data as well as to determine burn-up and cooling time of the fuel elements onsite at the Advanced Test Reactor (ATR) canal. This study makes a recommendation of the viability of implementing a permanent fuel scanning system at the ATR canal and leads3 to the full design of a permanent fuel scan system. The study consisted at first in determining if it was possible and which equipment was necessary to collect useful spectra from ATR fuel elements at the canal adjacent tomore » the reactor. Once it was establish that useful spectra can be obtained at the ATR canal the next step was to determine which detector and which configuration was better suited to predict burnup and cooling time of fuel elements non-destructively. Three different detectors of High Purity Germanium (HPGe), Lanthanum Bromide (LaBr3), and High Pressure Xenon (HPXe) in two system configurations of above and below the water pool were used during the study. The data collected and analyzed was used to create burnup and cooling time calibration prediction curves for ATR fuel. The next stage of the study was to determine which of the three detectors tested was better suited for the permanent system. From spectra taken and the calibration curves obtained, it was determined that although the HPGe detector yielded better results, a detector that could better withstand the harsh environment of the ATR canal was needed. The in-situ nature of the measurements required a rugged fuel scanning system, low in maintenance and easy to control system. Based on the ATR canal feasibility measurements and calibration results it was determined that the LaBr3 detector was the best alternative for canal in-situ measurements; however in order to enhance the quality of the spectra collected using this scintillator a deconvolution method was developed. Following the development of the deconvolution method for ATR applications the technique was tested using one-isotope, multi-isotope and fuel simulated sources. Burnup calibrations were perfomed using convoluted and deconvoluted data. The calibrations results showed burnup prediction by this method improves using deconvolution. The final stage of the deconvolution method development was to perform an irradiation experiment in order to create a surrogate fuel source to test the deconvolution method using experimental data. A conceptual design of the fuel scan system is path forward using the rugged LaBr3 detector in an above the water configuration and deconvolution algorithms.« less

Efficacy of xylene and passive ultrasonic irrigation on remaining root filling material during retreatment of anatomically complex teeth.

PubMed

Cavenago, B C; Ordinola-Zapata, R; Duarte, M A H; del Carpio-Perochena, A E; Villas-Bôas, M H; Marciano, M A; Bramante, C M; Moraes, I G

2014-11-01

To evaluate the volume of remaining filling material in the mesial root canals of mandibular molars after root canal retreatment with different procedures performed sequentially. The mesial root canals of 12 human first mandibular molars were instrumented using the BioRace system until a size 25, .06 taper instrument. The mesial roots were filled with gutta-percha and AH-Plus using a vertical compaction technique. The specimens were scanned using microcomputed tomography with a voxel size of 16.8 μm before and after the retreatment procedures. To remove the filling material, the root canals were enlarged until the size 40, .04 taper instrument. The second step was to irrigate the root canals with xylene in the attempt to clean the root canals with paper points. In the third step, the passive ultrasonic irrigation technique (PUI) was performed using 2.5% sodium hypochlorite. The initial and residual filling material volume (mm(3) ) after each step was evaluated from the 0.5 to 6.5 mm level. The obtained data were expressed in terms of percentage of residual filling material. Statistical analysis was performed using the Friedman test (P < 0.05). All specimens had residual filling materials after all retreatment procedures. Passive ultrasonic irrigation enhanced the elimination of residual filling material in comparison with the mechanical stage at the 0.5-2.5 mm and 4.5-6.5 mm levels (P < 0.05). No significant difference was found between xylene and PUI methods. Filling materials were not completely removed by any of the retreatment procedures. The use of xylene and PUI after mechanical instrumentation enhanced removal of materials during endodontic retreatment of anatomically complex teeth. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Relative position of the atrioventricular canal determines the electrical activation of developing reptile ventricles.

PubMed

Gregorovicova, Martina; Sedmera, David; Jensen, Bjarke

2018-04-19

Squamate reptiles appear to lack the specialized His/Purkinje system that enables the cardiac ventricle to be activated from apex to base as in mammals and birds. Instead, activation may simply spread from where the atrioventricular canal connects to the base. Gja5 , which encodes Cx40 that allows fast impulse propagation, was expressed throughout the ventricles of developing anole lizards. Activation was optically recorded in developing corn snake and central bearded dragon. Early embryonic ventricles were broad in shape, and activation propagated from the base to the right. Elongated ventricles of later stages were activated from base to apex. Before hatching, the snake ventricle developed a cranial extension on the left and activation now propagated from the base to the caudal apex and the cranial extension. In squamate reptiles, the pattern of electrical activation of the cardiac ventricle is dependent the position of the atrioventricular canal and the shape of the ventricle. © 2018. Published by The Company of Biologists Ltd.

[Modern concepts of etiology, pathogenesis and treatment approaches to endo-perio lesions].

PubMed

Grudianov, A I; Makeeva, M K; Piatgorskaia, N V

2013-01-01

A combination ofperiodontitis and pulp or periapical tissues inflammation in one tooth is known as endo-periodontal lesions. Such kind of lesion is serious problem of modern dentistry. It was found that pathogenic microflora of periodontal pocket and root canal of tooth with eno-perio lesion is almost the equal and consist of anaerobic microorganisms. Pathogenic effects have not only microorganisms but also their life products. Apical foramen, lateral and additional canals are physiological ways for pathogens migration. Inflammatory processes in these structures complicate each other. Lack of information among dentists about treatment possibilities of endo-perio lesions is a main reasons of extraction such kind of teeth. Simultaneous elimination of pathogens both from periodontal pocket and root canal is a key factor for effective treatment. Periodontal status is main factor for prognosis of tooth with endo-perio lesion, because of it treatment of endo-perio lesions should consist of two stages: infection elimination and regeneration of tooth-supported structures.

Effect of Wildfire on Hydrological Processes in a Monoculture Invasive Grass Catchment within the Panama Canal Watershed

NASA Astrophysics Data System (ADS)

Regina, J. A.; Ogden, F. L.

2014-12-01

Hydrological processes in the humid tropics are poorly understood and an important topic when it comes to watershed management in the seasonal tropics. The Smithsonian Tropical Research Institute, Panama Canal Watershed Experiment, Agua Salud Project, seeks to understand these processes and quantify the long-term effects of different land cover and uses across the Panama Canal Watershed. One question posed by this project concerns the hydrologic role of fire in tropical environments. Within the Panama Canal Watershed, fire has seen widespread use among agriculturalists. This study focused on a monoculture invasive grass (Saccharum spontaneum) catchment. Specifically, the effects of significant wildfire events on hydrological processes in the catchment were analyzed. The catchment is within Panama's protected Soberania National Park, which is part of the greater Panama Canal Watershed. Installed instrumentation includes a rain gauge cluster, a two-stage v-notch weir, atmometer and an assortment of meteorological and automated geochemical sampling systems. Spatial, rainfall, runoff and ET data across the catchment is available from 2009-2013. Various hydrologic characteristics, such as runoff ratio, peak flow per unit area, time to peak, runoff duration, and leaf area index, from before and after the events were compared. These characteristics are related to rates of ground water recharge and the occurrence of flash floods. This study provides a baseline from which the potential impacts of fire on hydrological processes in tropical environments can be analyzed.

Apparatus for measuring the decontamination factor of a multiple filter air-cleaning system

DOEpatents

Ortiz, John P.

1986-01-01

An apparatus for measuring the overall decontamination factor of first and second filters located in a plenum. The first filter separates the plenum's upstream and intermediate chambers. The second filter separates the plenum's intermediate and downstream chambers. The apparatus comprises an aerosol generator that generates a challenge aerosol. An upstream collector collects unfiltered aerosol which is piped to first and second dilution stages and then to a laser aerosol spectrometer. An intermediate collector collects challenge aerosol that penetrates the first filter. The filtered aerosol is piped to the first dilution stage, diluted, and then piped to the laser aerosol spectrometer which detects single particles. A downstream collector collects challenge aerosol that penetrates both filters. The twice-filtered aerosol is piped to the aerosol spectrometer. A pump and several valves control the movement of aerosol within the apparatus.

Apparatus for measuring the decontamination factor of a multiple filter air-cleaning system

DOEpatents

Ortiz, J.P.

1985-07-03

An apparatus for measuring the overall decontamination factors of first and second filters located in a plenum. The first filter separates the plenum's upstream and intermediate chambers. The second filter separates the plenum's intermediate and downstream chambers. The apparatus comprises an aerosol generator that generates a challenge aerosol. An upstream collector collects unfiltered aerosol which is piped to first and second dilution stages and then to a laser aerosol spectrometer. An intermediate collector collects challenge aerosol that penetrates the first filter. The filtered aerosol is piped to the first dilution stage, diluted, and then piped to the laser aerosol spectrometer which detects single particles. A downstream collector collects challenge aerosol that penetrates both filters. The twice-filtered aerosol is piped to the aerosol spectrometer. A pump and several valves control the movement of aerosol within the apparatus.

Rainfall, discharge, and water-quality data during stormwater monitoring, H-1 storm drain, Oahu, Hawaii, July 1, 2009, to June 30, 2010

USGS Publications Warehouse

Presley, Todd K.; Jamison, Marcael T.J.

2010-01-01

Storm runoff water-quality samples were collected as part of the State of Hawaii Department of Transportation Stormwater Monitoring Program. The program is designed to assess the effects of highway runoff and urban runoff collected by the H-1 storm drain on the Manoa-Palolo Drainage Canal. This report summarizes rainfall, discharge, and water-quality data collected between July 1, 2009, and June 30, 2010. As part of this program, rainfall and continuous discharge data were collected at the H-1 storm drain. During the year, sampling strategy and sample processing methods were modified to improve the characterization of the effects of discharge from the storm drain on the Manoa-Palolo Drainage Canal. During July 1, 2009, to February 1, 2010, samples were collected from only the H-1 storm drain. Beginning February 2, 2010, samples were collected simultaneously from the H-1 storm drain and the Manoa-Palolo Drainage Canal at a location about 50 feet upstream of the discharge point of the H-1 storm drain. Three storms were sampled during July 1, 2009, to June 30, 2010. All samples were collected using automatic samplers. For the storm of August 12, 2009, grab samples (for oil and grease, and total petroleum hydrocarbons) and a composite sample were collected. The composite sample was analyzed for total suspended solids, nutrients, and selected dissolved and total (filtered and unfiltered) trace metals (cadmium, chromium, nickel, copper, lead, and zinc). Two storms were sampled in March 2010 at the H-1 storm drain and from the Manoa-Palolo Drainage Canal. Two samples were collected during the storm of March 4, 2010, and six samples were collected during the storm of March 8, 2010. These two storms were sampled using the modified strategy, in which discrete samples from the automatic sampler were processed and analyzed individually, rather than as a composite sample, using the simultaneously collected samples from the H-1 storm drain and from the Manoa-Palolo Drainage Canal. The discrete samples were analyzed for some or all of the following constituents: total suspended solids, nutrients, oil and grease, and selected dissolved (filtered) trace metals (cadmium, chromium, nickel, copper, lead, and zinc). Five quality-assurance/quality-control samples were analyzed during the year. These samples included one laboratory-duplicate, one field-duplicate, and one matrix-spike sample prepared and analyzed with the storm samples. In addition, two inorganic blank-water samples, one sample at the H-1 storm drain and one sample at the Manoa-Palolo Drainage Canal, were collected by running the blank water (water purified of all inorganic constituents) through the sampling and processing systems after cleaning automatic sampler lines to verify that the sampling lines were not contaminated.

Effect of low-head lock and dam structures on migration and spawning of American shad and striped bass in the Cape Fear River, North Carolina

USGS Publications Warehouse

Smith, Joseph A.; Hightower, Joseph E.

2012-01-01

Anadromous fish populations within the Cape Fear River, North Carolina, have declined substantially since the late 1800s. Three low-head lock-and-dam (LD) structures on the river (LD-1–3) contributed to this decline by limiting access to upstream spawning habitat. We used egg sampling and sonic telemetry to examine the effects of the LD structures on migration and spawning activity of American shad Alosa sapidissima and striped bassMorone saxatilis. Egg distribution and stage of development suggested that most of the American shad spawning took place downstream from the lowermost structure, LD-1. The predicted mean density of stage-1 American shad eggs at a water temperature of 21°C was 895 eggs/1,000 m3 (95% credible interval [CI] = 800–994) below LD-1; 147 eggs/1,000 m3 (95% CI = 103–197) below LD-2; and 32 eggs/1,000 m3 (95% CI = 17–49) below the uppermost structure, LD-3. The probability of capturing a stage-1 American shad egg was strongly dependent on water temperature and hour of egg collection. Transmitter detections for 20 sonic-tagged American shad and 20 striped bass in 2008 showed that for both species, the majority of fish moved upstream of LD-1; 35% of American shad and 25% of striped bass migrated upstream of LD-3. Based on passage rates at the three LD structures, American shad would be expected to be most abundant downstream of LD-1 and upstream of LD-3. For striped bass, the river section between LD-2 and LD-3 had the highest egg collections and highest predicted proportion of the run. In combination, these results demonstrate that the locking program provides some access to historical spawning habitat, although further improvements in fish passage could benefit both species.

Reconnecting fragmented sturgeon populations in North American rivers

DOE PAGES

Jager, Yetta; Forsythe, Patrick S.; McLaughlin, Robert L.; ...

2016-02-24

The majority of large North American rivers are fragmented by dams that interrupt migrations of wide-ranging fishes like sturgeons. Reconnecting habitat is viewed as an important means of protecting sturgeon species in U.S. rivers because these species have lost between 5% and 60% of their historical ranges. Unfortunately, facilities designed to pass other fishes have rarely worked well for sturgeons. The most successful passage facilities were sized appropriately for sturgeons and accommodated bottom-oriented species. For upstream passage, facilities with large entrances, full-depth guidance systems, large lifts, or wide fishways without obstructions or tight turns worked well. However, facilitating upstream migrationmore » is only half the battle. Broader recovery for linked sturgeon populations requires safe round-trip passage involving multiple dams. The most successful downstream passage facilities included nature-like fishways, large canal bypasses, and bottom-draw sluice gates. We outline an adaptive approach to implementing passage that begins with temporary programs and structures and monitors success both at the scale of individual fish at individual dams and the scale of metapopulations in a river basin. The challenge will be to learn from past efforts and reconnect North American sturgeon populations in a way that promotes range expansion and facilitates population recovery.« less

Multipurpose Rotating Rake Arrays for Integrated Inlet and Fan Stage Performance Measurement

NASA Technical Reports Server (NTRS)

Wolter, John D.

2017-01-01

Low-pressure-ratio fan stage performance measurement requires precise measurement of conditions upstream and downstream of the fan stage. This presentation will discuss the rotating rake arrays used for the recent Boundary Layer Ingesting Inlet-Distortion-Tolerant Fan experiment in the NASA Glenn 8 by 6 foot wind tunnel. To achieve precise measurements, simulations of the rake sampling from pre-test CFD (Computerized Fluid Dynamics) solutions were used to optimize the number and locations of rake instruments.

Earth Observations taken by the Expedition 25 crew

NASA Image and Video Library

2010-09-30

ISS025-E-005504 (30 Sept. 2010) --- Syr Dar’ya River floodplain in Kazakhstan, central Asia is featured in this image photographed by an Expedition 25 crew member on the International Space Station. Central Asia’s most important cotton-growing region is concentrated in the floodplain of the Syr Dar’ya, and is irrigated by water from the river. The floodplain is shown here as a tangle of twisting meanders and loops (center). The darkest areas are brushy vegetation along the present course (filled with blue-green water); wisps of vegetation are also visible along flanking swampy depressions, or sloughs. An older floodplain appears as an area of more diffuse dark vegetation (upper left), where a pattern of relict meander bends is overlain by a rectangular pattern of cotton fields. The straight channel of a new diversion canal—one of sixteen from this point downstream—can be seen along the east bank of the river. The older floodplain area is fed from the Chardara Reservoir immediately upstream (not shown). Half the river flow is controlled from reservoirs, and half from direct water take-off from canals. By contrast with the intensive agricultural use of water shown here, upstream water control in the mountain valleys is oriented more toward power generation. The river flows for a total distance of 2,200 kilometers from the Tien Shan Mountains westward and northwestward to the Aral Sea—the dying waterbody at the low point of the basin far to the northwest. Withdrawals of water from the river for agriculture have continued for many decades. Although the Syr Dar’ya is the second largest river flowing into the sea, its discharge is not very large. As such, it has been easily depleted, with none of its water today reaching the Aral Sea. Control of the river is vested in the Syr Dar’ya Basin Water Organization run by nations with territory in the Syr Dar’ya basin. Some of the organization’s main efforts are accurate gauging of water use along the river course, and repair of canals to reduce widespread water loss by leakage.

A coupled surface-water and ground-water flow model (MODBRANCH) for simulation of stream-aquifer interaction

USGS Publications Warehouse

Swain, Eric D.; Wexler, Eliezer J.

1996-01-01

Ground-water and surface-water flow models traditionally have been developed separately, with interaction between subsurface flow and streamflow either not simulated at all or accounted for by simple formulations. In areas with dynamic and hydraulically well-connected ground-water and surface-water systems, stream-aquifer interaction should be simulated using deterministic responses of both systems coupled at the stream-aquifer interface. Accordingly, a new coupled ground-water and surface-water model was developed by combining the U.S. Geological Survey models MODFLOW and BRANCH; the interfacing code is referred to as MODBRANCH. MODFLOW is the widely used modular three-dimensional, finite-difference ground-water model, and BRANCH is a one-dimensional numerical model commonly used to simulate unsteady flow in open- channel networks. MODFLOW was originally written with the River package, which calculates leakage between the aquifer and stream, assuming that the stream's stage remains constant during one model stress period. A simple streamflow routing model has been added to MODFLOW, but is limited to steady flow in rectangular, prismatic channels. To overcome these limitations, the BRANCH model, which simulates unsteady, nonuniform flow by solving the St. Venant equations, was restructured and incorporated into MODFLOW. Terms that describe leakage between stream and aquifer as a function of streambed conductance and differences in aquifer and stream stage were added to the continuity equation in BRANCH. Thus, leakage between the aquifer and stream can be calculated separately in each model, or leakages calculated in BRANCH can be used in MODFLOW. Total mass in the coupled models is accounted for and conserved. The BRANCH model calculates new stream stages for each time interval in a transient simulation based on upstream boundary conditions, stream properties, and initial estimates of aquifer heads. Next, aquifer heads are calculated in MODFLOW based on stream stages calculated by BRANCH, aquifer properties, and stresses. This process is repeated until convergence criteria are met for head and stage. Because time steps used in ground-water modeling can be much longer than time intervals used in surface- water simulations, provision has been made for handling multiple BRANCH time intervals within one MODFLOW time step. An option was also added to BRANCH to allow the simulation of channel drying and rewetting. Testing of the coupled model was verified by using data from previous studies; by comparing results with output from a simpler, four-point implicit, open-channel flow model linked with MODFLOW; and by comparison to field studies of L-31N canal in southern Florida.

Sugarcane Genotype Selection on Muck and Sand Soils in Florida — a Case for Dedicated Environments

USDA-ARS?s Scientific Manuscript database

Traditionally, the cooperative sugarcane (Saccharum spp.) breeding program located at Canal Point has selected genotypes exclusively on muck soils in the early to middle stages of the program. Only about 0.20% of genotypes are ever tested on sand, resulting in the possibility that many sand-adapted ...

Sugarcane Genotype Selection on Muck and Sand Soils in Florida — a Case for Dedicated Environments

USDA-ARS?s Scientific Manuscript database

Traditionally, the cooperative sugarcane breeding program at Canal Point, Florida has selected genotypes exclusively on muck soils in the early to middle stages of the program, resulting in the possibility that many genotypes adapted to sand soils are discarded. The objective of this study was to de...

Screening for sugarcane brown rust in first clonal stage of the Canal Point sugarcane breeding program

USDA-ARS?s Scientific Manuscript database

Sugarcane (Saccharum spp.) brown rust (caused by Puccinia melanocephala H. & P. Sydow) was first reported in the United States in 1978 and is still one of great challenges for sugarcane production. A better understanding of sugarcane genotypic variation in response to brown rust will help optimize b...

[Specific features of digestive function development in larvae of some salmonid fish].

PubMed

Ershova, T S; Volkova, I V; Zaĭtseva, V F

2004-01-01

We studied the activities of digestive enzymes responsible for the digestion of food carbohydrate and protein components in plant-eating fish at various stages of larval development. The activities of all digestive enzymes tend to rise during larval development. Species specific features of the alimentary canal functioning have been described.

Integration of Canal and Otolith Inputs by Central Vestibular Neurons Is Subadditive for Both Active and Passive Self-Motion: Implication for Perception

PubMed Central

Carriot, Jerome; Jamali, Mohsen; Brooks, Jessica X.

2015-01-01

Traditionally, the neural encoding of vestibular information is studied by applying either passive rotations or translations in isolation. However, natural vestibular stimuli are typically more complex. During everyday life, our self-motion is generally not restricted to one dimension, but rather comprises both rotational and translational motion that will simultaneously stimulate receptors in the semicircular canals and otoliths. In addition, natural self-motion is the result of self-generated and externally generated movements. However, to date, it remains unknown how information about rotational and translational components of self-motion is integrated by vestibular pathways during active and/or passive motion. Accordingly, here, we compared the responses of neurons at the first central stage of vestibular processing to rotation, translation, and combined motion. Recordings were made in alert macaques from neurons in the vestibular nuclei involved in postural control and self-motion perception. In response to passive stimulation, neurons did not combine canal and otolith afferent information linearly. Instead, inputs were subadditively integrated with a weighting that was frequency dependent. Although canal inputs were more heavily weighted at low frequencies, the weighting of otolith input increased with frequency. In response to active stimulation, neuronal modulation was significantly attenuated (∼70%) relative to passive stimulation for rotations and translations and even more profoundly attenuated for combined motion due to subadditive input integration. Together, these findings provide insights into neural computations underlying the integration of semicircular canal and otolith inputs required for accurate posture and motor control, as well as perceptual stability, during everyday life. PMID:25716854

An uncertainty analysis of the flood-stage upstream from a bridge.

PubMed

Sowiński, M

2006-01-01

The paper begins with the formulation of the problem in the form of a general performance function. Next the Latin hypercube sampling (LHS) technique--a modified version of the Monte Carlo method is briefly described. The essential uncertainty analysis of the flood-stage upstream from a bridge starts with a description of the hydraulic model. This model concept is based on the HEC-RAS model developed for subcritical flow under a bridge without piers in which the energy equation is applied. The next section contains the characteristic of the basic variables including a specification of their statistics (means and variances). Next the problem of correlated variables is discussed and assumptions concerning correlation among basic variables are formulated. The analysis of results is based on LHS ranking lists obtained from the computer package UNCSAM. Results fot two examples are given: one for independent and the other for correlated variables.

Cancer of the Anal Canal: Diagnosis, Staging and Follow-Up with MRI.

PubMed

Durot, Carole; Dohan, Anthony; Boudiaf, Mourad; Servois, Vincent; Soyer, Philippe; Hoeffel, Christine

2017-01-01

Although a rare disease, anal cancer is increasingly being diagnosed in patients with risk factors, mainly anal infection with the human papilloma virus. Magnetic resonance imaging (MRI) with external phased-array coils is recommended as the imaging modality of choice to grade anal cancers and to evaluate the response assessment after chemoradiotherapy, with a high contrast and good anatomic resolution of the anal canal. MRI provides a performant evaluation of size, extent and signal characteristics of the anal tumor before and after treatment, as well as lymph node involvement and extension to the adjacent organs. MRI is also particularly helpful in the assessment of complications after treatment, and in the diagnosis for relapse of the diseases.

Modeling the combined influence of host dispersal and waterborne fate and transport on pathogen spread in complex landscapes

PubMed Central

Lu, Ding; McDowell, Julia Z.; Davis, George M.; Spear, Robert C.; Remais, Justin V.

2012-01-01

Environmental models, often applied to questions on the fate and transport of chemical hazards, have recently become important in tracing certain environmental pathogens to their upstream sources of contamination. These tools, such as first order decay models applied to contaminants in surface waters, offer promise for quantifying the fate and transport of pathogens with multiple environmental stages and/or multiple hosts, in addition to those pathogens whose environmental stages are entirely waterborne. Here we consider the fate and transport capabilities of the human schistosome Schistosoma japonicum, which exhibits two waterborne stages and is carried by an amphibious intermediate snail host. We present experimentally-derived dispersal estimates for the intermediate snail host and fate and transport estimates for the passive downstream diffusion of cercariae, the waterborne, human-infective parasite stage. Using a one dimensional advective transport model exhibiting first-order decay, we simulate the added spatial reach and relative increase in cercarial concentrations that dispersing snail hosts contribute to downstream sites. Simulation results suggest that snail dispersal can substantially increase the concentrations of cercariae reaching downstream locations, relative to no snail dispersal, effectively putting otherwise isolated downstream sites at increased risk of exposure to cercariae from upstream sources. The models developed here can be applied to other infectious diseases with multiple life-stages and hosts, and have important implications for targeted ecological control of disease spread. PMID:23162675

Proposal of a new radiological classification system for spinal meningiomas as a descriptive tool and surgical guide.

PubMed

Bayoumi, Ahmed B; Laviv, Yosef; Yokus, Burhan; Efe, Ibrahim E; Toktas, Zafer Orkun; Kilic, Turker; Demir, Mustafa K; Konya, Deniz; Kasper, Ekkehard M

2017-11-01

1) To provide neurosurgeons and radiologists with a new quantitative and anatomical method to describe spinal meningiomas (SM) consistently. 2) To provide a guide to the surgical approach needed and amount of bony resection required based on the proposed classification. 3) To report the distribution of our 58 cases of SM over different Stages and Subtypes in correlation to the surgical treatment needed for each case. 4) To briefly review the literature on the rare non-conventional surgical corridors to resect SM. We reviewed the literature to report on previously published cohorts and classifications used to describe the location of the tumor inside the spinal canal. We reviewed the cases that were published prior showing non-conventional surgical approaches to resect spinal meningiomas. We proposed our classification system composed of Staging based on maximal cross-sectional surface area of tumor inside canal, Typing based on number of quadrants occupied by tumor and Subtyping based on location of the tumor bulk to spinal cord. Extradural and extra-spinal growth were also covered by our classification. We then applied it retrospectively on our 58 cases. 12 articles were published illustrating overlapping terms to describe spinal meningiomas. Another 7 articles were published reporting on 23 cases of anteriorly located spinal meningiomas treated with approaches other than laminectomies/laminoplasties. 4 Types, 9 Subtypes and 4 Stages were described in our Classification System. In our series of 58 patients, no midline anterior type was represented. Therefore, all our cases were treated by laminectomies or laminoplasties (with/without facetectomies) except a case with a paraspinal component where a costotransversectomy was needed. Spinal meningiomas can be radiologically described in a precise fashion. Selection of surgical corridor depends mainly on location of tumor bulk inside canal. Copyright © 2017 Elsevier B.V. All rights reserved.

Mitomycin-C- or Cisplatin-Based Chemoradiotherapy for Anal Canal Carcinoma: Long-Term Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olivatto, Luis O., E-mail: olivatto@inca.gov.b; Cabral, Vania; Rosa, Arthur

2011-02-01

Purpose: To evaluate the long-term efficacy of concurrent radiotherapy with mitomycin-C (MMC)-based or cisplatin (CP)-based combinations in a cohort of patients with locally advanced anal canal carcinoma. Methods and Materials: Between 1988 and 2000, 179 patients with locally advanced anal canal carcinoma were treated at the Instituto Nacional de Cancer with two cycles of chemotherapy during Weeks 1 and 5 of radiotherapy. 5-Fluorouracil (750 mg/m{sup 2} 120-hour infusion or 1,000 mg/m{sup 2} 96-hour infusion) plus CP (100 mg/m{sup 2}) on the first day of each cycle or MMC (10-15 mg/m{sup 2}) on the first day of Cycle 1 was administeredmore » concurrent with radiotherapy (total dose, 55-59.4 Gy). Of the 179 patients, 60% were included from a randomized trial initiated at the Instituto Nacional de Cancer in 1991 that compared concurrent chemoradiotherapy with MMC vs. CP. Results: The median follow-up for the whole chemoradiotherapy group was 83 months. The median patient age was 58 years, 57% had Stage T3-T4 tumors, and 35% had N-positive disease. The 5-year cumulative colostomy rate was not significantly different between the CP group (22%) and MMC group (29%; p = .28). The actuarial 10-year overall survival and disease-free survival rate for the CP group was 54% and 49% and for the MMC group was 52% and 53%, respectively (p = .32 and p = .92, respectively). On multivariate analysis, male gender (p = .042) and advanced Stage T3-T4 disease (p <.0001) were statistically significant for worse disease-free survival. Stage T3-T4 (p = .039) and N+ (p = .039) disease remained independently significant for overall survival. Conclusion: Long-term follow-up has confirmed the good results of chemoradiotherapy with CP plus 5-fluorouracil, which seem to provide results equivalent to those with MMC plus 5-fluorouracil.« less

Detailed study of water quality, bottom sediment, and biota associated with irrigation drainage in the Klamath Basin, California and Oregon, 1990-92

USGS Publications Warehouse

Dileanis, Peter D.; Schwarzbach, S.E.; Bennett, Jewel

1996-01-01

The effect of irrigation drainage on the water quality and wildlife of the Klamath Basin in California and Oregon was evaluated during 1990-92 as part of the National Irrigation Water Quality Program of the U.S. Department of the Interior. The study focused on land serviced by the Bureau of Reclamation Klamath Project, which supplies irrigation water to agricultural land in the Klamath Basin and the Lost River Basin. The Tule Lake and Lower Klamath National Wildlife Refuges, managed by the U.S. Fish and Wildlife Service, are in the study area. These refuges provide critical resting and breeding habitat for waterfowl on the Pacific flyway and are dependent on irrigation drainwater from upstream agriculture for most of their water supply. Water-quality characteristics throughout the study area were typical of highly eutrophic systems during the summer months of 1991 and 1992. Dissolved-oxygen concentrations and pH tended to fluctuate each day in response to diurnal patterns of photosynthesis, and frequently exceeded criteria for protection of aquatic organisms. Nitrogen and phosphorus concentrations were generally at or above threshold levels characteristic of eutrophic lakes and streams. At most sites the bulk of dissolved nitrogen was organically bound. Elevated ammonia concentrations were common in the study area, especially down- stream of drain inputs. High pH of water increased the toxicity of ammonia, and concentrations exceeded criteria at sites upstream and downstream of irrigated land. Concentrations of ammonia in samples from small drains on the Tule Lake refuge leaseland were higher than those measured in the larger, integrating drains at primary monitoring sites. The mean ammonia concentration in leaseland drains [1.21 milligrams per liter (mg/L)] was significantly higher than the mean concentration in canals delivering water to the leaseland fields (0.065 mg/L) and higher than concentrations reported to be lethal to Daphnia magna (median lethal concentration of 0.66 mg/L). Dissolved- oxygen concentrations also were lower, and Daphnia survivability measured during in situ bioassays was correspondingly lower in the leaseland drains than in water delivery canals. In static laboratory bioassays, water samples collected at the primary monitoring sites caused toxicity in up to 78 percent of Lemna minor tests, in up to 49 percent of Xenopus laevis tests, in 17 percent and 8 percent of Hyalella azteca and Pimephales promelas tests, respectively, and 0 percent in Daphnia magna tests. In situ exposure at the sites caused mortality in more than 83 percent of Pimephales tests and in more than 41 percent of Daphnia and Hyalella tests. Much of the observed toxicity appears to have been caused by low dissolved oxygen, high pH, and ammonia. Although water in the study area was toxic to a variety of organisms, no statistically significant differences in the degree of toxicity between sites were observed above or below irrigated agricultural land in any of the bioassays. Pesticides were frequently detected in water samples collected at the monitoring sites during the 1991 and 1992 irrigation seasons. Among the most frequently detected compounds were the herbicides simazine, metribuzin, EPTC, and metolachlor and the insecticide terbufos. All the insecticides detected were at concentrations substantially below acute toxicity values reported for aquatic organisms. The herbicide acrolein has been used extensively in the basin to manage aquatic plant growth in irrigation canals and drains. The concentration of acrolein was monitored in a canal near Tule Lake after an application in order to evaluate the potential for the pesticide to be transported to refuge waters. Although acrolein concentrations were toxic to fish in the channels adjacent to Tule Lake, very little of the canal water entered the refuge during the monitoring period. Organochlorine pesticide concentrations in 25 surficial sediment samples collected in 1990 were below bas

Endodontic-periodontic bifurcation lesions: a novel treatment option.

PubMed

Lin, Shaul; Tillinger, Gabriel; Zuckerman, Offer

2008-05-01

The purpose of this preliminary clinical report is to suggest a novel treatment modality for periodontal bifurcation lesions of endodontic origin. The study consisted of 11 consecutive patients who presented with periodontal bifurcation lesions of endodontic origin (endo-perio lesions). All patients were followed-up for at least 12 months. Treatment included calcium hydroxide with iodine-potassium iodide placed in the root canals for 90 days followed by canal sealing with gutta-percha and cement during a second stage. Dentin bonding was used to seal the furcation floor to prevent the ingress of bacteria and their by-products to the furcation root area through the accessory canals. A radiographic examination showed complete healing of the periradicular lesion in all patients. Probing periodontal pocket depths decreased to 2 to 4 mm (mean 3.5 mm), and resolution of the furcation involvement was observed in post-operative clinical evaluations. The suggested treatment of endo-perio lesions may result in complete healing. Further studies are warranted. This treatment method improves both the disinfection of the bifurcation area and the healing process in endodontically treated teeth considered to be hopeless.

Endo-periodontal lesion--endodontic approach.

PubMed

Jivoinovici, R; Suciu, I; Dimitriu, B; Perlea, P; Bartok, R; Malita, M; Ionescu, C

2014-01-01

Endo-perio lesions might be interdependent because of the vascular and anatomic connections between the pulp and the periodontium. The aim of this study is to emphasise that primary endodontic lesion heals after a proper instrumentation, disinfection and sealing of the endodontic space. The primary endodontic lesion with a secondary periodontal involvement first requires an endodontic therapy and, in the second stage, a periodontal therapy. The prognosis is good, with an adequate root canal treatment; it depends on the severity of the periodontal disease, appropriate healing time and the response to the treatment. A correct diagnosis is sometimes difficult; an accurate identification of the etiologic factors is important for an adequate treatment. Primary perio-endo lesion may heal after a proper disinfection and sealing of the endodontic system, the one-year follow-up radiograph showing bonny repair. Invasive periodontal procedures should be avoided at that moment. The microorganisms and by-products from the infected root canal may cross accessory and furcal canals and determine sinus tract and loss of attachment. In both clinical cases presented in this article, successful healing was obtained after a proper disinfection and sealing of the endodontic system.

Relation of drainage problems to high ground-water levels, Coconut Grove area, Oahu, Hawaii

USGS Publications Warehouse

Swain, L.A.; Huxel, C.J.

1971-01-01

Purpose and Scope In 1969, hydrologic data-collection sites were established in and around the Coconut Grove area for the purpose of measuring directly the relationship between rainfall, runoff, ground-water levels, the level of water in Kawainui Swamp and the canals, and tidal fluctuations. The primary objective was to identify the causes of the occurrence and persistence of flooding and to gain data on which to base recommendations for remedial action. The scope of the study included establishing and operating flow and stage-recording gages on the Swamp, Kawainui Canal, and the inner canal; periodic and repeated measurements of ground-water level in test borings throughout the residential area; collection and analysis of soil and construction borings made for engineering purposes; the assembly and analysis of all available data relating surface and subsurface flow conditions, and the development of conclusions as to the causes and means to alleviate the flooding. This report summarizes the information collected from October 1969 to June 1971, includes analysis of the data, and discusses the probable causes of flooding.

Improvement of urban water environment of Kaohsiung City, Taiwan, by ecotechnology.

PubMed

Yang, Lei

2012-01-01

Kaohsiung City is the second largest city in Taiwan and suffers from serious floods during the wet season, but it also badly needs water during the dry season. As economic development advances and pollutants increase, water pollution and shortage of water resources become issues of concern for local people in Kaohsiung. A project has been proposed by the city government and executed by the authors to establish a system of sustainable water management in urban areas. In this system, the Caogong Canals, irrigation channels which were established 170 years ago during the Ching Dynasty of China and are still used today for irrigation, were renovated to bring stable and clean water to the urban areas. It is planned to pump clean water into the canal from a river near the city. In this project, 12 constructed wetland systems, functioning as wetland parks, stormwater storage tanks or eco-detention ponds, were built in the city, and the Caogong Canals are planned to connect all these urban constructed wetlands in the second stage of the project.

Control of the actin cytoskeleton in root hair development.

PubMed

Pei, Weike; Du, Fei; Zhang, Yi; He, Tian; Ren, Haiyun

2012-05-01

The development of root hair includes four stages: bulge site selection, bulge formation, tip growth, and maturation. The actin cytoskeleton is involved in all of these stages and is organized into distinct arrangements in the different stages. In addition to the actin configuration, actin isoforms also play distinct roles in the different stages. The actin cytoskeleton is regulated by actin-binding proteins, such as formin, Arp2/3 complex, profilin, actin depolymerizing factor, and villin. Some upstream signals, i.e. calcium, phospholipids, and small GTPase regulate the activity of these actin-binding proteins to produce the proper actin configuration. We constructed a working model on how the actin cytoskeleton is controlled by actin-binding proteins and upstream signaling in root hair development based on the current literature: at the tip of hairs, actin polymerization appears to be facilitated by Arp2/3 complex that is activated by small GTPase, and profilin that is regulated by phosphatidylinositol 4,5-bisphosphate. Meanwhile, actin depolymerization and turnover are likely mediated by villin and actin depolymerizing factor, which are stimulated by calcium. At the shank, actin cables are produced by formin and villin. Under the complicated interaction, the actin cytoskeleton is controlled spatially and temporally during root hair development. © 2012 Elsevier Ireland Ltd. All rights reserved.

Fuel injection staged sectoral combustor for burning low-BTU fuel gas

DOEpatents

Vogt, Robert L.

1981-01-01

A high-temperature combustor for burning low-BTU coal gas in a gas turbine is described. The combustor comprises a plurality of individual combustor chambers. Each combustor chamber has a main burning zone and a pilot burning zone. A pipe for the low-BTU coal gas is connected to the upstream end of the pilot burning zone; this pipe surrounds a liquid fuel source and is in turn surrounded by an air supply pipe; swirling means are provided between the liquid fuel source and the coal gas pipe and between the gas pipe and the air pipe. Additional preheated air is provided by counter-current coolant air in passages formed by a double wall arrangement of the walls of the main burning zone communicating with passages of a double wall arrangement of the pilot burning zone; this preheated air is turned at the upstream end of the pilot burning zone through swirlers to mix with the original gas and air input (and the liquid fuel input when used) to provide more efficient combustion. One or more fuel injection stages (second stages) are provided for direct input of coal gas into the main burning zone. The countercurrent air coolant passages are connected to swirlers surrounding the input from each second stage to provide additional oxidant.

Fuel injection staged sectoral combustor for burning low-BTU fuel gas

DOEpatents

Vogt, Robert L.

1985-02-12

A high-temperature combustor for burning low-BTU coal gas in a gas turbine is described. The combustor comprises a plurality of individual combustor chambers. Each combustor chamber has a main burning zone and a pilot burning zone. A pipe for the low-BTU coal gas is connected to the upstream end of the pilot burning zone: this pipe surrounds a liquid fuel source and is in turn surrounded by an air supply pipe: swirling means are provided between the liquid fuel source and the coal gas pipe and between the gas pipe and the air pipe. Additional preheated air is provided by counter-current coolant air in passages formed by a double wall arrangement of the walls of the main burning zone communicating with passages of a double wall arrangement of the pilot burning zone: this preheated air is turned at the upstream end of the pilot burning zone through swirlers to mix with the original gas and air input (and the liquid fuel input when used) to provide more efficient combustion. One or more fuel injection stages (second stages) are provided for direct input of coal gas into the main burning zone. The countercurrent air coolant passages are connected to swirlers surrounding the input from each second stage to provide additional oxidant.

Groundwater Surface Water Interactions in a Gold-Mined Dredged Floodplain of the Merced River

NASA Astrophysics Data System (ADS)

Sullivan, L.; Conklin, M. H.; Ghezzehei, T. A.

2012-12-01

The Merced River, originating in the Sierra Nevada, California, drains a watershed with an area of ~3,305 km2. Merced River has been highly altered due to diversions, mechanically dredged mining, and damming. A year of groundwater-surface water interactions were studied to elucidate the hydrological connection between the Main Canal, an unlined canal that contains Merced River water flows parallel to the river with an average elevation of 89m, the highly conductive previously dredged floodplain, and the Merced River with an average elevation of 84m. Upstream of the study reach, located in an undredged portion, of the floodplain are two fish farms that have been operating for approximately 40 years. This study reach has been historically important for salmon spawning and rearing, where more than 50% of the Chinook salmon of the Merced River spawn. Currently salmon restoration is focusing gravel augmentation and adding side channel and ignoring groundwater influences. Exchanges between the hyporheic and surrounding surface, groundwater, riparian, and alluvial floodplain habitats occur over a wide range of spatial and temporal scales. Pressure transducers were installed in seven wells and four ponds located in the dredged floodplain. All wells were drilled to the Mehrten Formation, a confining layer, and screened for last 3m. These groundwater well water levels as well as the surface water elevations of the Main Canal and the Merced River were used to determine the direction of sublateral surface flows using Groundwater Vistas as a user interface for MODFLOW. The well and pond waters and seepage from the river banks were sampled for anion/cation, dissolved organic carbon, total nitrogen, total iron, and total dissolved iron concentrations to determine water sources and the possibility of suboxic water. Field analysis indicated that water in all wells and ponds exhibit low dissolved oxygen, high conductivity rates, and oxidation/reduction potentials that switched from oxidizing to reductive during the course of the monitoring. Chemical analysis indicates that there are three sources of water for this floodplain: the Merced River and Main Canal, (which are chemically very similar), the waters from the fish hatchery, and precipitation. The well closest to the fish hatcheries had C:N ratio of 1:1, highly carbon-limited system. MODFLOW particle tracer experiments were performed, results indicate that that travel time between the Main Canal and Merced River are approximately 10-15 years. The hydraulic gradient set up by the groundwater connection between Main Canal and the Merced River, insures that any effluent released by the fish farms will be transported to the Merced River. Conclusions of the study are that the waters that seep from the Main Canal to the Merced River in this area can be sub-oxic, which is not conducive to salmon spawning and are detrimental to the developing salmonid embryo. Due to the causal connections between the hydrological system of the Merced River floodplain and the riverine system, habitat rehabilitation must target not only the surface water but also important subsurface hydrological components.

A method for aircraft afterburner combustion without flameholders

NASA Astrophysics Data System (ADS)

Birmaher, Shai

2009-12-01

State of the art aircraft afterburners employ spray bars to inject fuel and flameholders to stabilize the combustion process. Such afterburner designs significantly increase the length (and thus weight), pressure losses, and observability of the engine. This thesis presents a feasibility study of a compact 'prime and trigger' (PAT) afterburner concept that eliminates the fuel spray bars and flameholders and, thus, eliminates the above-mentioned problems. In this concept, afterburner fuel is injected just upstream or in between the turbine stages. As the fuel travels through the turbine stages, it evaporates, mixes with the bulk flow, and undergoes some chemical reactions without any significant heat release, a process referred to as 'priming'. Downstream of the turbine stages, combustion could take place through autoignition. However, if fuel autoignition does not occur or if autoignition does not produce a combustion zone that is stable and highly efficient, then a low power pilot, or 'trigger', can be used to control the combustion process. The envisioned trigger for the PAT concept is a jet of product gas from ultra-rich hydrocarbon/air combustion that is injected through the afterburner liner. This 'partial oxidation' (POx) gas, which consists mostly of H2, CO, and diluents, rapidly produces radicals and heat that accelerate the autoignition of the primed mixture and, thus, provide an anchor point for the afterburner combustion process. The objective of this research was to demonstrate the feasibility of the PAT concept by showing that (1) combustion of fuel injected within or upstream of turbine stages can occur only downstream of the turbine stages, and (2) the combustion zone is compact, stable and efficient. This was accomplished using two experimental facilities, a developed theoretical model, and Chemkin simulations. The first facility, termed the Afterburner Facility (AF), simulated the bulk flow temperature, velocity and O2 content through a turbojet combustor, turbine stage and afterburner. To model the PAT concept, Jet-A was injected upstream of the simulated turbine stage and a H2 jet was used to trigger the primed Jet-A combustion process downstream of the turbine stage. H2 was used because POx gas was not available for experiments. The second facility, termed the Propane Autoignition Combustor (PAC), was essentially a scaled-down, simplified version of the AF. The PAC experiments focused on the trigger stage of the PAT concept, using H 2 in lieu of POx gas and employing measurement techniques that were in some ways more detailed than in the AF experiments. The developed model simulated the physics of fuel priming in the AF and predicted the Jet-A autoignition location. It was used to predict and interpret the AF results and to study the feasibility of the PAT concept at pressures outside the AF operating range. Finally, the Chemkin simulations were used to examine the effect of several POx gas compositions on the Jet-A/vitiated-air autoignition process; to compare the POx and H2 triggers; and to explore several reasons for why POx gas and H2 are suitable trigger mechanisms. he experimental, theoretical, and numerical results obtained in this investigation indicated that the PAT concept provides a feasible approach to afterburner combustion. The experiments in the AF showed that the ignition delay of Jet-A is sufficiently long to allow fuel injection within turbine stages without significant heat release upstream of the afterburner. In the AF experiments without the H2 trigger, Jet-A combustion was achieved through autoignition; however, the autoignition combustion zone exhibited large axial fluctuations and low combustion efficiency. The H2 trigger was able to shift the combustion zone upstream, make it more compact, reduce fluctuations in its axial position, and raise the combustion efficiency to nearly 100%. The PAC experiments also showed that a H2 trigger can shift the combustion zone upstream, make it more compact, and increase the combustion efficiency. The PAC results were obtained with lower O 2 content and higher equivalence ratios than in the AF. Therefore, the combined AF and PAC results suggested that the PAT concept is feasible over a wide range of operating conditions. The developed model showed good agreement with the AF results. It also predicted that the PAT concept is feasible at bulk flow pressures outside the AF operating range. Finally, the Chemkin results showed that both the H2 and POx gas triggers can significantly reduce the ignition delay time of primed Jet-A/vitiated air mixtures. Thus, POx gas is a suitable trigger for the PAT concept and should be tested in future experimental investigations.

[Treatment tactics of hemorroidal disease stage III-IV].

PubMed

Goncharuk, R A; Stegniĭ, K V; Krekoten', A A; Grossman, S S; Sarychev, V A

2013-01-01

The Miligan-Morgan's operation has long been considered to be the "golden standard" of hemorrhoids' stage I-III treatment. The invention of distal branches of the upper rectal artery' suture ligation with mucopexia and lifting of the anal canal mucosa discovered new possibilities for hemorrhoids surgery, though there are still some questions considering long-term results. 151 cases of recurrence within 1-6 months were analyzed. The use of CT-angiography with 3D reconstruction of the upper rectal artery allowed to chose the operative technique more relevant and thus improve the treatment results.

The impact of anaemia on treatment outcome in patients with squamous cell carcinoma of anal canal and anal margin.

PubMed

Oblak, Irena; Cesnjevar, Monika; Anzic, Mitja; Hadzic, Jasna But; Ermenc, Ajra Secerov; Anderluh, Franc; Velenik, Vaneja; Jeromen, Ana; Korosec, Peter

2016-03-01

Radiochemotherapy is the main treatment for patients with squamous cell carcinoma of the anal canal. Anaemia is reported to have adverse effect on survival in cancer patients. The aim of the study was to evaluate the influence of anaemia on radiochemotherapy treatment outcome in patients with squamous cell carcinoma of the anal canal. One hundred consecutive patients with histologically confirmed squamous cell carcinoma of the anal canal were treated radically with 3-dimensional conformal or intensity-modulated radiation therapy followed by brachytherapy or external beam radiotherapy boost and with concurrent mitomycin C and 5-fluorouracil. The influence on survival of pre-treatment, mean on-treatment and end-of-treatment haemoglobin (Hb) concentrations was studied. The 5-year locoregional control, disease free survival, disease specific survival and overall survival rates for all patients were 72%, 71%, 77% and 62%, respectively. In univariate analysis, patients with pre-treatment and end-of-treatment Hb > 120 g/L survived statistically significantly better compared to patients with Hb ≤ 120 g/L. Patients with mean on-treatment Hb > 120 g/L only had statistically significant better locoregional control and overall survival than patients with Hb ≤ 120 g/L. In multivariate analysis, independent prognostic factors were pre-treatment Hb (> 120 g/L vs. ≤ 120 g/L) for overall survival (hazard ratio [HR] = 0.419, 95% confidence interval [CI] = 0.190-0.927, p = 0.032) and stage (I & II vs. III) for disease specific (HR = 3.523, 95% CI = 1.375-9.026, p = 0.009) and overall survival (HR = 2.230, 95% CI = 1.167-4.264, p = 0.015). The pre-treatment, mean on-treatment and end-of-treatment Hb concentration > 120 g/L carried better prognosis for patients for with squamous cell carcinoma of the anal canal treated with radiochemotherapy. The pre-treatment Hb > 120 g/L was an independent prognostic factor for overall survival of patients with anal canal cancer.

Effect of retained fractured instruments on tooth resistance to vertical fracture with or without attempt at removal.

PubMed

Madarati, A A; Qualtrough, A J E; Watts, D C

2010-11-01

To investigate the effect of retained fractured endodontic instruments on root strength and to evaluate the effectiveness of several root filling materials in reinforcing roots that had undergone unsuccessful attempt at removal of fractured instruments. Seventy five mandibular premolar roots were divided into five groups. In group A (control), canals were prepared to a size F5-ProTaper instrument and filled with gutta-percha and TubliSeal sealer fragments. In the experimental groups (B, C, D and E), 4 mm of F5-ProTaper instruments were fractured in the apical one-third of the canal and then treated as follows: in group B, the fragments were left in situ without attempt at removal, and canals were filled with gutta-percha and TubliSeal sealer (GP No Removal). In groups C, D and E, an attempt at removal of the fragment was simulated by preparing a staging platform coronal to the fragment using modified Gates Glidden burs (No 2-5). Canals in group C were filled with gutta-percha and TubliSeal sealer (GP Removal), group D filled with Resilon (Resilon Removal) and group E with mineral trioxide aggregate (MTA Removal). Roots then underwent vertical fracture. Data were analysed using the one-way anova at P<0.05. Roots in the GP Removal group had significantly lower values for mean force for fracture (404.9 N). There was no significant difference between the control group and GP No Removal (765.2 and 707.8, respectively). Resilon Removal and MTA Removal groups (577.3 and 566.6 N) were not significantly different from the GP No Removal group. Leaving fractured instruments in the apical one-third of the canal does not appear to affect the resistance of the root to vertical fracture; Resilon and MTA appear to compensate for root dentine loss that occurred as a consequence of attempts at retrieval of fractured instruments when used as canal filling materials. © 2010 International Endodontic Journal.

Simulation of the water-table altitude in the Biscayne Aquifer, southern Dade County, Florida, water years 1945-89

USGS Publications Warehouse

Merritt, M.L.

1995-01-01

A digital model of the flow system in the highly permeable surficial aquifer of southern Dade County, Florida, was constructed for the purposes of better understanding processes that influence the flow system and of supporting the construction of a subregional model of the transport of brackish water from a flowing artesian well. Problems that needed resolution in this endeavor included the development of methods to represent the influence of flowing surface water in seasonally inundated wetlands and the influence of a network of controlled canals developed in stages during the simulation time period (water years 1945-89). An additional problem was the general lack of natural aquifer boundaries near the boundaries of the study area. The model construction was based on a conceptual description of the Biscayne aquifer developed from the results of previous U.S. Geological Survey investigations. Modifications were made to an existing three- dimensional finite-difference simulator of ground- water flow to enable an upper layer of the grid to represent seasonally occurring overland sheetflow in a series of transient simulations of water levels from 1945 to 1989. A rewetting procedure was developed for the simulator that permitted resaturation of cells in this layer when the wet season recurred. An "equivalent hydraulic conductivity" coefficient was assigned to the overland flow layer that was analogous, subject to various approximations, to the use of the Manning equation. The surficial semiconfining peat and marl layers, levees, canals, and control structures were also represented as part of the model grid with the appropriate choices of hydraulic coefficient values. For most of the Biscayne aquifer grid cells, the value assigned to hydraulic conductivity for model calibration was 30,000 feet per day and the value assigned to porosity was 20 percent. Boundary conditions were specified near data sites having long-term records of surface-water stages or water-table altitudes, and modifications to the simulator permitted the specification of time- varying pressures at boundary grid cells. Rainfall data from a station in Homestead generally were used as an areally uniform rainfall specification throughout the modeled region. Maximum evapotranspiration rates ranged seasonally from a minimum of 0.08 inch per day in January to a maximum of 0.21 inch per day between June and October. Shallow-root and deep-root zone depths for the evaportranspiration calculation were 3 and 20 feet in the coastal ridge and were 0.10 and 5 feet in the glades regions where peat and marl covers occurred. Results of sensitivity analyses indicated that the simulations of stages and water levels were relatively unresponsive to 50 percent changes in aquifer hydraulic conductivity, porosity, and the equivalent hydraulic conductivity of overland flow. However, 20 percent changes in rainfall and maximum evapotranspiration rates produced significantly different water levels, as did interchange of coastal ridge and glades deep-root zone (extinction) depths. Water levels were simulated very well at most measurement sites. Sensitivity analyses illustrated the significant influence of the uncontrolled agricultural drainage canals on pre- 1968 regional water levels and the further influence of Black Creek Canal in draining a region of high water after 1961. Other analyses indicated that the flood-control system of 1968-82 lowered peak water levels in the affected region by as much as 1.5 feet in the wet summers of 1968, 1969, and 1981, and that Levee 67 Extended channeled flows from the S-12 spillway structures and raised overland flow stages in Shark River Slough. Hypothetical scenarios of well-field pumping in the vicinity of Levee 31N indicated that the pumping induced a significant amount of recharge from the adjacent borrow canal, the degree of which depended on the distance between the canal and the well field. The computed ratio of evapotranspiration to ra

[Carcinoma of the uterine cervical canal. Staging and biometric assessment with magnetic resonance].

PubMed

Fischetti, S G; Politi, G; Lomeo, E; Garozzo, G; Di Leo, S; Nuciforo, G

1994-10-01

In uterine cervical canal carcinoma, the current clinical FIGO criteria often fail not only to differentiate stage IA2 from stage IB but also to demonstrate possible parametrial involvement. Moreover, the analysis of tumor volume and of the depth of neoplastic stromal invasion is not very reliable. The authors investigated MR accuracy in the definition of such variables: to this purpose, 24 patients with histologically confirmed endocervical adenocarcinoma were submitted to MRI, which was performed with an 0.5-T superconductive magnet. Sagittal and oblique transverse or sometimes coronal SE images, oriented so as to be perpendicular to longitudinal cervical major axis were obtained with T2 weighting (TR 1800 ms, TE 25-90 ms). MR data were correlated with pathologic findings. MR accuracy in demonstrating parametrial involvement was 92%, its sensitivity was 86% and specificity 97%. Volumetric MR data showed a high correlation (r = 0.970) with those derived from pathologic findings. In 92% of cases stromal invasion exceeded 5 mm. MRI, thanks to its high accuracy, should be included in diagnostic pretreatment protocols, even though FIGO criteria do not require it yet, especially in the presence of an endocervical adenocarcinoma. Moreover, the accurate definition of tumor volume can allow less extensive surgery with the same survival rates and fewer complications, which are frequently observed after radical hysterectomy.

ELIMINATION OF INTRACANAL INFECTION IN DOGS' TEETH WITH INDUCED PERIAPICAL LESIONS AFTER ROTARY INSTRUMENTATION: INFLUENCE OF DIFFERENT CALCIUM HYDROXIDE PASTES

PubMed Central

Soares, Janir Alves; Leonardo, Mário Roberto; da Silva, Léa Assed Bezerra; Tanomaru, Mário; Ito, Izabel Yoko

2006-01-01

The aim of this study was to evaluate the antiseptic efficacy of rotary instrumentation associated with calcium hydroxide-based pastes prepared with different vehicles and antiseptics. Chronic periapical lesions were experimentally induced in 72 premolar root canals of four dogs. Under controlled asepsis, after initial microbiological sampling (A1), the root canals were instrumented using the ProFile system in conjunction with 5.25% sodium hypochlorite and the intracanal medication was placed. Four experimental groups were formed according to the pastes used: group 1- Calen (n=18), group 2- Calen+CPMC (n=20), group 3- Ca(OH)2 p.a.+ anaesthetic solution (n=16) and group 4- Ca(OH)2 p.a.+ 2% chlorhexidine digluconate (n=18). After 21 days, the pastes were removed; the canals were emptied and 96 hours later a second microbiological sample was obtained (A2). The incidence of positive microbiological cultures and the number of cfus in stages A1 and A2 were compared statistically by the Wilcoxon test while the influence of the different treatments in intracanal infection was evaluated by Kruskal-Wallis test at 5% significance level (p<0.05). Large numbers of strict and facultative anaerobes, and viridans group streptococci were found in 100% of root canals of A1 samples. Among A2 samples, all treatments showed significant reduction of cfus and positive cultures (p<0.05), but only groups 3 and 4 showed 100% of root canals free of microorganisms. Rotary instrumentation plus NaOCl 5.25% associated with intracanal medication produced a drastic reduction or elimination of intracanal microbiota, whose performance was not influenced by the nature of the vehicle or the antiseptic added to the Ca(OH)2 p.a. PMID:19089068

Moving domain computational fluid dynamics to interface with an embryonic model of cardiac morphogenesis.

PubMed

Lee, Juhyun; Moghadam, Mahdi Esmaily; Kung, Ethan; Cao, Hung; Beebe, Tyler; Miller, Yury; Roman, Beth L; Lien, Ching-Ling; Chi, Neil C; Marsden, Alison L; Hsiai, Tzung K

2013-01-01

Peristaltic contraction of the embryonic heart tube produces time- and spatial-varying wall shear stress (WSS) and pressure gradients (∇P) across the atrioventricular (AV) canal. Zebrafish (Danio rerio) are a genetically tractable system to investigate cardiac morphogenesis. The use of Tg(fli1a:EGFP) (y1) transgenic embryos allowed for delineation and two-dimensional reconstruction of the endocardium. This time-varying wall motion was then prescribed in a two-dimensional moving domain computational fluid dynamics (CFD) model, providing new insights into spatial and temporal variations in WSS and ∇P during cardiac development. The CFD simulations were validated with particle image velocimetry (PIV) across the atrioventricular (AV) canal, revealing an increase in both velocities and heart rates, but a decrease in the duration of atrial systole from early to later stages. At 20-30 hours post fertilization (hpf), simulation results revealed bidirectional WSS across the AV canal in the heart tube in response to peristaltic motion of the wall. At 40-50 hpf, the tube structure undergoes cardiac looping, accompanied by a nearly 3-fold increase in WSS magnitude. At 110-120 hpf, distinct AV valve, atrium, ventricle, and bulbus arteriosus form, accompanied by incremental increases in both WSS magnitude and ∇P, but a decrease in bi-directional flow. Laminar flow develops across the AV canal at 20-30 hpf, and persists at 110-120 hpf. Reynolds numbers at the AV canal increase from 0.07±0.03 at 20-30 hpf to 0.23±0.07 at 110-120 hpf (p< 0.05, n=6), whereas Womersley numbers remain relatively unchanged from 0.11 to 0.13. Our moving domain simulations highlights hemodynamic changes in relation to cardiac morphogenesis; thereby, providing a 2-D quantitative approach to complement imaging analysis.

Upstream Design and 1D-CAE

NASA Astrophysics Data System (ADS)

Sawada, Hiroyuki

Recently, engineering design environment of Japan is changing variously. Manufacturing companies are being challenged to design and bring out products that meet the diverse demands of customers and are competitive against those produced by rising countries(1). In order to keep and strengthen the competitiveness of Japanese companies, it is necessary to create new added values as well as conventional ones. It is well known that design at the early stages has a great influence on the final design solution. Therefore, design support tools for the upstream design is necessary for creating new added values. We have established a research society for 1D-CAE (1 Dimensional Computer Aided Engineering)(2), which is a general term for idea, methodology and tools applicable for the upstream design support, and discuss the concept and definition of 1D-CAE. This paper reports our discussion about 1D-CAE.

Innervation of the cow's inner ear derived from micro-computed tomography

NASA Astrophysics Data System (ADS)

Costeur, Loic; Mennecart, Bastien; Khimchenko, Anna; Müller, Bert; Schulz, Georg

2017-09-01

The innervation of the inner ear has been thoroughly investigated in humans and in some animal models such as the guinea pig, the rabbit, the cat, the dog, the rat, the pig and some monkeys. Ruminant inner ears are still poorly known and their innervation was never investigated despite its potential interest in phylogenetic reconstructions. Following earlier works on the ontogeny of the cow's ear, we expand our understanding of this structure by reconstructing the fine innervation pattern of the inner ear of the cow in two ontogenetic stages, at 7 months gestation and at an adult age. Since we work on dry skeletal specimens, only the endocast of the innervation inside the petrosal bone was reconstructed up to the internal acoustic meatus. The paths of the facial and vestibulocochlear nerves could be reconstructed together with that of the spiral ganglion canal. The nerves have a very fibrous pattern. The bony cavities of the ampular and utricular branches of the vestibulocochlear nerve could also be reconstructed. Our observations confirm that not all bony structures are present in foetal stages since the branch of cranial nerve VII is not visible on the foetus but very broad on the adult stage. The fibrous pattern within the modiolus connecting the spiral canal to the cochlear nerve is also less dense than in the adult stage. The shape of the branch of cranial nerve VII is very broad in the cow ending in a large hiatus Fallopii; this, together with the above-mentioned particularities, could constitute relevant observations for phylogenetical purposes when more data will be made available.

Shifting patterns of nitrogen excretion and amino acid catabolism capacity during the life cycle of the sea lamprey (Petromyzon marinus).

PubMed

Wilkie, Michael P; Claude, Jaime F; Cockshutt, Amanda; Holmes, John A; Wang, Yuxiang S; Youson, John H; Walsh, Patrick J

2006-01-01

The jawless fish, the sea lamprey (Petromyzon marinus), spends part of its life as a burrow-dwelling, suspension-feeding larva (ammocoete) before undergoing a metamorphosis into a free swimming, parasitic juvenile that feeds on the blood of fishes. We predicted that animals in this juvenile, parasitic stage have a great capacity for catabolizing amino acids when large quantities of protein-rich blood are ingested. The sixfold to 20-fold greater ammonia excretion rates (J(Amm)) in postmetamorphic (nonfeeding) and parasitic lampreys compared with ammocoetes suggested that basal rates of amino acid catabolism increased following metamorphosis. This was likely due to a greater basal amino acid catabolizing capacity in which there was a sixfold higher hepatic glutamate dehydrogenase (GDH) activity in parasitic lampreys compared with ammocoetes. Immunoblotting also revealed that GDH quantity was 10-fold and threefold greater in parasitic lampreys than in ammocoetes and upstream migrant lampreys, respectively. Higher hepatic alanine and aspartate aminotransferase activities in the parasitic lampreys also suggested an enhanced amino acid catabolizing capacity in this life stage. In contrast to parasitic lampreys, the twofold larger free amino acid pool in the muscle of upstream migrant lampreys confirmed that this period of natural starvation is accompanied by a prominent proteolysis. Carbamoyl phosphate synthetase III was detected at low levels in the liver of parasitic and upstream migrant lampreys, but there was no evidence of extrahepatic (muscle, intestine) urea production via the ornithine urea cycle. However, detection of arginase activity and high concentrations of arginine in the liver at all life stages examined infers that arginine hydrolysis is an important source of urea. We conclude that metamorphosis is accompanied by a metabolic reorganization that increases the capacity of parasitic sea lampreys to catabolize intermittently large amino acid loads arising from the ingestion of protein rich blood from their prey/hosts. The subsequent generation of energy-rich carbon skeletons can then be oxidized or retained for glycogen and fatty acid synthesis, which are essential fuels for the upstream migratory and spawning phases of the sea lamprey's life cycle.

A Notch-dependent transcriptional hierarchy promotes mesenchymal transdifferentiation in the cardiac cushion.

PubMed

Chang, Alex C Y; Garside, Victoria C; Fournier, Michele; Smrz, Justin; Vrljicak, Pavle; Umlandt, Patricia; Fuller, Megan; Robertson, Gordon; Zhao, Yongjun; Tam, Angela; Jones, Steven J M; Marra, Marco A; Hoodless, Pamela A; Karsan, Aly

2014-07-01

Valvuloseptal defects are the most common congenital heart defects. Notch signaling-induced endothelial-to-mesenchymal transition (EMT) in the atrioventricular canal (AVC) cushions at murine embryonic day (E)9.5 is a required step during early valve development. Insights to the transcriptional network that is activated in endocardial cells (EC) during EMT and how these pathways direct valve maturation are lacking. We show that at E11.5, AVC-EC retain the ability to undergo Notch-dependent EMT when explanted on collagen. EC-Notch inhibition at E10.5 blocks expression of known mesenchymal genes in E11.5 AVC-EC. To understand the genetic network and AVC development downstream of Notch signaling beyond E9.5, we constructed Tag-Seq libraries corresponding to different cell types of the E11.5 AVC and atrium in wild-type mice and in EC-Notch inhibited mice. We identified 1,400 potential Notch targets in the AVC-EC, of which 124 are transcription factors (TF). From the 124 TFs, we constructed a transcriptional hierarchy and identify 10 upstream TFs within the network. We validated 4 of the upstream TFs as Notch targets that are enriched in AVC-EC. Functionally, we show these 4 TFs regulate EMT in AVC explant assays. These novel signaling pathways downstream of Notch are potentially relevant to valve development. © 2014 Wiley Periodicals, Inc.

Sensitivity of the downward to sweeping velocity ratio to the bypass flow percentage along a guide wall for downstream fish passage

USGS Publications Warehouse

Mulligan, Kevin; Towler, Brett; Haro, Alexander J.; Ahlfeld, David P.

2017-01-01

Partial-depth impermeable guidance structures (or guide walls) are used as a method to assist in the downstream passage of fish at a hydroelectric facility. However, guide walls can result in a strong downward velocity causing the approaching fish to pass below the wall and into the direction of the turbine intakes. The objective of this study was to describe how the ratio of the vertical velocity to the sweeping velocity magnitude changes along the full length and depth of a guide wall under a wide range of bypass flow percentages within a power canal. This paper focused on two guide wall configurations, each set at an angle of 45 ° to the approaching flow field and at a depth of 10 and 20 ft (3.05 and 6.10 m). The hydraulic conditions upstream of each guide wall configuration were shown to be impacted by a change in the bypass flow percentage, not only near the bypass but also at upstream sections of the guide wall. Furthermore, the effect of changing the bypass flow percentage was similar for both guide wall depths. In both cases, the effect of increasing the bypass flow percentage was magnified closer to the bypass and deeper in the water column along the guide wall.

Spawning chronology, nest site selection and nest success of smallmouth bass during benign streamflow conditions

USGS Publications Warehouse

Dauwalter, D.C.; Fisher, W.L.

2007-01-01

We documented the nesting chronology, nest site selection and nest success of smallmouth bass Micropterus dolomieu in an upstream (4th order) and downstream (5th order) reach of Baron Fork Creek, Oklahoma. Males started nesting in mid-Apr. when water temperatures increased to 16.9 C upstream, and in late-Apr. when temperatures increased to 16.2 C downstream. Streamflows were low (77% upstream to 82% downstream of mean Apr. streamflow, and 12 and 18% of meanjun. streamflow; 47 and 55 y of record), and decreased throughout the spawning period. Larger males nested first upstream, as has been observed in other populations, but not downstream. Upstream, progeny in 62 of 153 nests developed to swim-up stage. Downstream, progeny in 31 of 73 nests developed to swim-up. Nesting densities upstream (147/km) and downstream (100/km) were both higher than any densities previously reported. Males selected nest sites with intermediate water depths, low water velocity and near cover, behavior that is typical of smallmouth bass. Documented nest failures resulted from human disturbance, angling, and longear sunfish predation. Logistic exposure models showed that water velocity at the nest was negatively related and length of the guarding male was positively related to nest success upstream. Male length and number of degree days were both positively related to nest success downstream. Our results, and those of other studies, suggest that biological factors account for most nest failures during benign (stable, low flow) streamflow conditions, whereas nest failures attributed to substrate mobility or nest abandonment dominate when harsh streamflow conditions (spring floods) coincide with the spawning season.

Comparison of the South Florida Natural System Model with Pre-canal Everglades Hydrology Estimated from Historical Sources

USGS Publications Warehouse

McVoy, Christopher; Park, Winifred A.; Obeysekera, Jayantha

1996-01-01

Preservation and restoration of the remaining Everglades ecosystem is focussed on two aspects: improving upstream water quality and improving 'hydropatterns' - the timing, depth and flow of surface water. Restoration of hydropatterns requires knowledge of the original pre-canal drainage conditions as well as an understanding of the soil, topo-graphic, and vegetation changes that have taken place since canal drainage began in the 1880's. The Natural System Model (NSM), developed by the South Florida Water Management District (SFWMD) and Everglades National Park, uses estimates of pre-drainage vegetation and topography to estimate the pre-drainage hydrologic response of the Everglades. Sources of model uncertainty include: (1) the algorithms, (2) the parameters (particularly those relating to vegetation roughness and evapotranspiration), and (3) errors in the assumed pre-drainage vegetation distribution and pre-drainage topography. Other studies are concentrating on algorithmic and parameter sources of uncertainty. In this study we focus on the NSM output -- predicted hydropattern -- and evaluate this by comparison with all available direct and indirect information on pre-drainage hydropatterns. The unpublished and published literature is being searched exhaustively for observations of water depth, flow direction, flow velocity and hydroperiod, during the period prior and just after drainage (1840-1920). Additionally, a comprehensive map of soils in the Everglades region, prepared in the 1940's by personnel from the University of Florida Agricultural Experiment Station, the U.S. Soil Conservation Service, the U.S. Geological Survey, and the Everglades Drainage District, is being used to identify wetland soils and to infer the spatial distribution of pre-drainage hydrologic conditions. Detailed study of this map and other early soil and vegetation maps in light of the history of drainage activities will reveal patterns of change and possible errors in the input to the NSM. Changes in the wetland soils are important because of their effects on topography (soil subsidence) and in their role as indicators of hydropattern.

Cyclic aggradation and downcutting, fluvial response to volcanic activity, and calibration of soil-carbonate stages in the western Grand Canyon, Arizona

USGS Publications Warehouse

Lucchitta, Ivo; Curtis, Garniss H.; Davis, Marie E.; Davis, Sidney W.; Turrin, Brent

2000-01-01

In the western Grand Canyon, fluvial terraces and pediment surfaces, both associated with a Pleistocene basalt flow, document Quaternary aggradation and downcutting by the Colorado River, illuminate the river's response to overload and the end of overload, and allow calibration of soil-carbonate stages and determination of downcutting rates. Four downcutting-aggradation cycles are present. Each begins with erosion of older deposits to form a new river channel in which a characteristic suite of deposits is laid down. The current cycle (I) started ~700 yr B.P. The oldest (IV) includes the 603,000 ± 8000 to 524,000 ± 7000 yr Black Ledge basalt flow, emplaced when the river channel was ~30 m higher than it is now. The flow is overlain by basalt-cobble gravel and basalt sand. Soils reach the stage V level of carbonate development. Calibrated ages for soil stages are Stage V, ~525,000 yr; stage IV, <525,000 yr, ≥250,000 yr; stage III, <250,000 yr, ≥100,000 yr. The monolithologic basalt sand beds represent overloading by volcanic ash produced by an eruption 30-50 km upstream. The basalt-cobble beds signal breaching and rapid destruction of lava dams and erosion of flows. These deposits show that the Colorado River responds to overload by aggrading vigorously during the overload and then downcutting equally vigorously when the overload ends. The overall downcutting rate for the interval studied is 1.6 cm/1000 yr, much lower than rates upstream. The current downcutting rate, 11-14 m/1000 yr, likely is a response both to the end of late Pleistocene and early Holocene overload and to the reduction of sediment supply caused by Glen Canyon Dam.

Use of acoustic technology to define hydraulic characteristics of an estuary near the Mississippi Gulf Coast

USGS Publications Warehouse

Van Wilson, K.

2004-01-01

An Acoustic Doppler Current Profiler (ADCP) was used on the Jourdan River at Interstate Highway 10 near Kiln, Mississippi, in 1996 to measure three-dimensional velocity vectors and water depths and in 1998, in combination with a global positioning system, to define channel bathymetry in the vicinity of the bridge. During a 25-hour period on September 19-20, 1996, 117 consecutive measurements of stage and discharge were obtained throughout a complete tidal cycle. These measurements were obtained during the time of year when headwater flows were minimal, and, therefore, the tidal-affected flow conditions were noticeable. The stage ranged from only 0.7 to 2.8 ft above sea level, but discharge ranged from 3,980 ft3/s flowing upstream to 5,580 ft 3/s flowing downstream. The average discharge during the 25-hour period was only 80 ft3/s flowing downstream. By using the ADCP, full downstream flow, bi-directional flow, and full upstream flow conditions were identified. If conventional measurement techniques had been used, the bi-directional flow conditions could not have been detected since flow direction would have been based on what was seen at the water surface. These measurements were used to define the lower range of the stage-storage-volume relation inland of the highway. On June 10, 1998, the ADCP, in combination with a global positional system, was used to define channel bathymetry for the river reach from about 3,500 ft upstream to about 2,500 ft downstream of the bridge. The bathymetry was compared to past soundings obtained in the vicinity of the bridge; as much as 18 ft of total scour was indicated to have occurred at a bridge pier. Copyright ASCE 2004.

Genotype x Harvest Date Analysis Reveals Late Sugar Phenotypes in Stage 2 of the Canal Point Sugarcane Cultivar Development Program

USDA-ARS?s Scientific Manuscript database

Florida’s sugarcane harvest season ranges from late October through early April. Commercial harvesting schedules can, however, be adversely affected by weather conditions that prevent entry of heavy equipment in the fields. The El Niño rainy season of 2015-2016 was such an example, where record rain...

[Treatment of cervical intraepithelial neoplasia using the CO2 laser].

PubMed

Trejo Solorzano, O; González Iñiguez, R

1991-04-01

The use of laser therapy in CIN, is a practical method that has revolutionized the treatment of a very common pathology, that is the cervical neoplasia in its early stages. 86 patients with different stages of cervical intraepithelial neoplasia, were studied. Patients in groups I (45 patients) y II (28 patients), were submitted to a vaporization crater of the whole transformation zone because of having the cervical canal free of lesion. In group III (13 patients), a cylinder of the cervix was done to perform histological study, whether the cervical canal was compromised or not. The cytology control results for group I were excellent; from (45 patients) who came to 3-month check-up 79.1% of the whole presented negative II. For group II (28 patients), in first pap smear two patients (7.1%) had CIN, the rest of smears were reported 66% negative II, and in the 30.6% negative I. For the group III 14.2% (5 patients) of the whole had abnormal results, the rest of the smears 73.5% of the results reported negative II. The incidence of failure for this procedure is similar to that of hysterectomy with the same therapeutic goal .

Best practices: Product category rule creation and use

EPA Science Inventory

Benefits of life cycle-based claims For most products, the majority of impact occurs upstream or downstream of product use . Single-stage claims for products (e.g., recycled content; energy efficient) don’t capture the relevance of that attribute in life-cycle environmental per...

Pilot project for a hybrid road-flooding forecasting system on Squaw Creek.

DOT National Transportation Integrated Search

2014-09-01

A network of 25 sonic stage sensors were deployed in the Squaw Creek basin upstream from Ames Iowa to determine : if the state-of-the-art distributed hydrological model CUENCAS can produce reliable information for all road crossings : including those...

Generation of forerunner electron beam during interaction of ion beam pulse with plasma

NASA Astrophysics Data System (ADS)

Hara, Kentaro; Kaganovich, Igor D.; Startsev, Edward A.

2018-01-01

The long-time evolution of the two-stream instability of a cold tenuous ion beam pulse propagating through the background plasma with density much higher than the ion beam density is investigated using a large-scale one-dimensional electrostatic kinetic simulation. The three stages of the instability are investigated in detail. After the initial linear growth and saturation by the electron trapping, a portion of the initially trapped electrons becomes detrapped and moves ahead of the ion beam pulse forming a forerunner electron beam, which causes a secondary two-stream instability that preheats the upstream plasma electrons. Consequently, the self-consistent nonlinear-driven turbulent state is set up at the head of the ion beam pulse with the saturated plasma wave sustained by the influx of the cold electrons from upstream of the beam that lasts until the final stage when the beam ions become trapped by the plasma wave. The beam ion trapping leads to the nonlinear heating of the beam ions that eventually extinguishes the instability.

Photographic copy of drawing by Modjeski and Masters, Engineers of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photographic copy of drawing by Modjeski and Masters, Engineers of the proposed Huey P. Long Bridge Widening. Original drawing located in the office of Modjeski and Masters, Consulting Engineers at 1055 St. Charles Avenue, New Orleans, LA. 70130. JUNE 30, 2004 DRAWING OF THE PROPOSED HUEY P. LONG BRIDGE WIDENING, U.S. 90, MAIN BRIDGE SUPERSTRUCTURE, SHOWING SEQUENCE OF CONSTRUCTION – 13, STAGE 1 AND STAGE 2 – PHASE 1 AND STAGE 2 – PHASE 2. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

MICROSCOPIC METABOLISM OF CALCIUM IN BONE. IV. Ca$sup 45$ DEPOSITION AND GROWTH RATE IN CANINE OSTEONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marshall, J.H.; Jowsey, J.; Rowland, R.E.

1959-02-01

The Ca/sup 45/ content of individual osteons in three dogs given single intravenous injections has been measured autoradiographically and correlated with osteon canal diameter measured from microradiographs. An osteon was found to contain up to 10/sup -6/ of the injected activity, its total activity per unit length being approximately proportional to the square of its canal diameter at the time of injection. The activities observed at 12 hours or 2 weeks after injection divided by the corresponding time integral of the blood specific activity yield an accretion rate for calcium at each canal diameter such that the half-diameter time formore » the canal of an average forming osteon in a rather wide distnibution is 3 plus or minus 1 weeks, which is consistent with direct observations of osteon growth. It is concluded that the intense concentrations or in vivo-deposited Ca/sup 45/ which we have observed in canine osteons 12 hours or more after injection are due to accretion of calcium in appositional growth at approximately the specific activity measured in the large veins. The nature of the Ca/sup 45/ uptake in osteons which have completed or arrested appositional growth before injection cannot be inferred from the present data, but such uptake is here of an order of magnitude less than that due to appositional growth. Comparison of calculated blood flow with observed osteon growth rate indieates that an osteon in the early stages of appositiona« less

General Dental Practitioners’ Concept towards Using Radiography and Apex-Locators in Endodontics

PubMed Central

Raoof, Maryam; Heidaripour, Maryam; Shahravan, Arash; Haghani, Jahangir; Afkham, Arash; Razifar, Mahsa; Mohammadizadeh, Sakineh

2014-01-01

Introduction: Despite being the gold standard as well as a routine technique in endodontics, radiographic working length (WL) determination owns many drawbacks. Electronic apex-locators (EALs) are recommended to complement radiographies. The aim of this study was to evaluate the perceptions of Iranian general dental practitioners (GDPs) towards using radiography and EAL. Methods and Materials: Three hundred and ninety one GDPs attending the 53th Iranian Dental Association Congress completed a questionnaire focusing on the use of radiography and EALs during the various stages of root canal treatment. The data was analyzed with the chi-square test with the level of significance set at 0.05. The results were then calculated as frequencies and percentages. Results: More than half of the GDPs reported using radiographs as the sole method for WL determination. A total of 30.4% of the practitioners were using the combined approach during root canal therapy of a single-rooted tooth, while 38.9% used this method in multi-rooted teeth. Approximately half of the respondents would not order follow-up radiographies after root canal treatment. Conclusion: Radiography continues to be the most common method for WL determination in Iran. PMID:25386209

Persistent apical periodontitis associated with a calcifying odontogenic cyst.

PubMed

Estrela, C; Decurcio, D A; Silva, J A; Mendonça, E F; Estrela, C R A

2009-06-01

To report a case of calcifying odontogenic cyst (COC) that was suggestive of apical periodontitis adjacent to the roots of the maxillary incisor teeth. Tooth 21 presented with clinical and radiographic signs of secondary infection, a post within the root canal and substantial internal tooth destruction; it was scheduled for endodontic surgery. Teeth 12 and 22 were root filled following the placement of a calcium hydroxide intracanal dressing for 21 days. Three attempts at root canal disinfection in tooth 11 were unsuccessful, and a persistent purulent drainage precluded completion of root canal treatment. Surgical enucleation of the periapical lesion was undertaken and the tissues submitted for histopathological examination. A diagnosis of COC was established based on the microscopic analysis. COC is an unusual benign lesion that represents 2% of all odontogenic lesions. Depending on the stage of development, it can mimic a large lesion associated with apical periodontitis and should therefore be considered in the differential diagnosis. In the case of COC, the definitive diagnosis can only be made with histopathological analysis. Persistent apical periodontitis may be of nonendodontic origin. * Histological examination is essential to establish the cause of persistent apical periodontitis. * Calcifying odontogenic cyst can mimic apical periodontitis.

Endo-periodontal lesion – endodontic approach

PubMed Central

Jivoinovici, R; Suciu, I; Dimitriu, B; Perlea, P; Bartok, R; Malita, M; Ionescu, C

2014-01-01

Endo-perio lesions might be interdependent because of the vascular and anatomic connections between the pulp and the periodontium. The aim of this study is to emphasise that primary endodontic lesion heals after a proper instrumentation, disinfection and sealing of the endodontic space. The primary endodontic lesion with a secondary periodontal involvement first requires an endodontic therapy and, in the second stage, a periodontal therapy. The prognosis is good, with an adequate root canal treatment; it depends on the severity of the periodontal disease, appropriate healing time and the response to the treatment. A correct diagnosis is sometimes difficult; an accurate identification of the etiologic factors is important for an adequate treatment. Primary perio-endo lesion may heal after a proper disinfection and sealing of the endodontic system, the one-year follow-up radiograph showing bonny repair. Invasive periodontal procedures should be avoided at that moment. The microorganisms and by-products from the infected root canal may cross accessory and furcal canals and determine sinus tract and loss of attachment. In both clinical cases presented in this article, successful healing was obtained after a proper disinfection and sealing of the endodontic system. PMID:25713618

Method and apparatus for producing synthesis gas

DOEpatents

Hemmings, John William; Bonnell, Leo; Robinson, Earl T.

2010-03-03

A method and apparatus for reacting a hydrocarbon containing feed stream by steam methane reforming reactions to form a synthesis gas. The hydrocarbon containing feed is reacted within a reactor having stages in which the final stage from which a synthesis gas is discharged incorporates expensive high temperature materials such as oxide dispersed strengthened metals while upstream stages operate at a lower temperature allowing the use of more conventional high temperature alloys. Each of the reactor stages incorporate reactor elements having one or more separation zones to separate oxygen from an oxygen containing feed to support combustion of a fuel within adjacent combustion zones, thereby to generate heat to support the endothermic steam methane reforming reactions.

Requirements, model and prototype for a multi-utility locational and security information hub.

DOT National Transportation Integrated Search

2015-11-01

This project lays the foundation for building an exchange hub for locational and security data and risk assessment of potential excavation work. It acts primarily at 2 stages: upstream of the mark-out process, as a decision support tool to help strea...

Long-term morphological evolution of a morphologically active man-made stream in the Netherlands

NASA Astrophysics Data System (ADS)

Eekhout, J.; Hoitink, T.

2010-12-01

Around 1770, a straight artificial canal (Gelderns-Nierskanaal) has been constructed between the River Niers and the River Meuse, crossing the border between Germany and the Netherlands, with the purpose of reducing flood risk in the downstream reaches of the River Niers. Whereas the German part of the canal is kept straight throughout time, the Dutch part was left unprotected and developed into a morphodynamically active stream featuring a meandering planform. The current planform and in-channel morphology are analyzed using airborne LiDAR data and historical topographic maps. Around the turn of the 18th century, the first attempts were made to make detailed topographic maps. From this time on, at least 16 topographic maps of the area around the stream were made. With the use of these historical topographic maps, a reconstruction is made of the planimetric shape of the stream over a period of 240 years. The LiDAR data show old meander belts at several places around the stream. Those belts compare well with the topographic maps. The sinuosity increases from upstream to downstream. This could be a consequence of the valley slope, where the upper part is flat and the slope increases in downstream direction. Besides, the LiDAR data show that erosion resulted in an incised valley, with dimensions to 50 m in width and 6 m in depth. Both the datasets are combined to make an estimate of the historical sediment budget of the stream.

Use of lubricant gel to shorten the second stage of labor during vaginal delivery.

PubMed

Aquino, Carmen Imma; Saccone, Gabriele; Troisi, Jacopo; Zullo, Fulvio; Guida, Maurizio; Berghella, Vincenzo

2018-05-27

Vaginal application of lubricant during labor has been studied to shorten the length of the second stage of labor. To evaluate whether vaginal application of lubricant shortens the second stage of labor. Electronic databases were searched from their inception until February 2018. No restrictions for language or geographic location were applied. Randomized controlled trials (RCTs) comparing the use of lubricant of the vaginal canal (ie intervention group) with a control group (ie no lubricant) in pregnant women with singleton gestation and cephalic presentation undergoing spontaneous vaginal delivery at term. Trials on other interventions that might impact second stage of labor (pushing methods, perineal massage, Ritgen's maneuver, etc.) were not included. All analyses were done using an intention-to-treat approach. The primary outcome was the length of the second stage of labor. Pooled analysis was performed using the random-effects model of DerSimonian and Laird to produce summary treatment effects in terms of mean difference (MD) with 95% confidence interval (CI). Three RCTs including 512 women evaluating the effect of lubricant application during labor were included in the meta-analysis. All trials included pregnant women with singleton gestations in cephalic presentation at term undergoing spontaneous vaginal delivery. One trial included only nulliparous women, while the other two included both nulliparous and multiparous women. Lubricant application started in the first stage before the active phase of labor, and was done intermittently by the midwife or the physician. A sterile gel was applied into the vaginal canal manually or with an applicator. All trials used water-soluble gel. The quantity of gel used was about 2-5 ml for each vaginal examination. There were no statistically significant differences, comparing women who received lubricant gel during labor with those who did not, in the lengths of second stage of labor (MD -7.11 minutes, 95% CI -15.60-1.38), of the first stage of labor, or of the active phase of the first stage of labor. No between-group differences were noticed in the risk of perineal lacerations, mode of delivery, and in the neonatal outcomes. Vaginal application of lubricant during labor does not reduce the length of the second stage of labor in pregnant women with singleton gestations undergoing an attempt at spontaneous vaginal delivery at term.

Biocorrosion of Endodontic Files through the Action of Two Species of Sulfate-reducing Bacteria: Desulfovibrio desulfuricans and Desulfovibrio fairfieldensis.

PubMed

Heggendorn, Fabiano Luiz; Gonçalves, Lucio Souza; Dias, Eliane Pedra; de Oliveira Freitas Lione, Viviane; Lutterbach, Márcia Teresa Soares

2015-08-01

This study assessed the biocorrosive capacity of two bacteria: Desulfovibrio desulfuricans and Desulfovibrio fairfieldensis on endodontic files, as a preliminary step in the development of a biopharmaceutical, to facilitate the removal of endodontic file fragments from root canals. In the first stage, the corrosive potential of the artificial saliva medium (ASM), modified Postgate E medium (MPEM), 2.5 % sodium hypochlorite (NaOCl) solution and white medium (WM), without the inoculation of bacteria was assessed by immersion assays. In the second stage, test samples were inoculated with the two species of sulphur-reducing bacteria (SRB) on ASM and modified artificial saliva medium (MASM). In the third stage, test samples were inoculated with the same species on MPEM, ASM and MASM. All test samples were viewed under an infinite focus Alicona microscope. No test sample became corroded when immersed only in media, without bacteria. With the exception of one test sample between those inoculated with bacteria in ASM and MASM, there was no evidence of corrosion. Fifty percent of the test samples demonstrated a greater intensity of biocorrosion when compared with the initial assays. Desulfovibrio desulfuricans and D. fairfieldensis are capable of promoting biocorrosion of the steel constituent of endodontic files. This study describes the initial development of a biopharmaceutical to facilitate the removal of endodontic file fragments from root canals, which can be successfully implicated in endodontic therapy in order to avoiding parendodontic surgery or even tooth loss in such events.

Closure of the vertebral canal in human embryos and fetuses.

PubMed

Mekonen, Hayelom K; Hikspoors, Jill P J M; Mommen, Greet; Kruepunga, Nutmethee; Köhler, S Eleonore; Lamers, Wouter H

2017-08-01

The vertebral column is the paradigm of the metameric architecture of the vertebrate body. Because the number of somites is a convenient parameter to stage early human embryos, we explored whether the closure of the vertebral canal could be used similarly for staging embryos between 7 and 10 weeks of development. Human embryos (5-10 weeks of development) were visualized using Amira 3D ® reconstruction and Cinema 4D ® remodelling software. Vertebral bodies were identifiable as loose mesenchymal structures between the dense mesenchymal intervertebral discs up to 6 weeks and then differentiated into cartilaginous structures in the 7th week. In this week, the dense mesenchymal neural processes also differentiated into cartilaginous structures. Transverse processes became identifiable at 6 weeks. The growth rate of all vertebral bodies was exponential and similar between 6 and 10 weeks, whereas the intervertebral discs hardly increased in size between 6 and 8 weeks and then followed vertebral growth between 8 and 10 weeks. The neural processes extended dorsolaterally (6th week), dorsally (7th week) and finally dorsomedially (8th and 9th weeks) to fuse at the midthoracic level at 9 weeks. From there, fusion extended cranially and caudally in the 10th week. Closure of the foramen magnum required the development of the supraoccipital bone as a craniomedial extension of the exoccipitals (neural processes of occipital vertebra 4), whereas a growth burst of sacral vertebra 1 delayed closure until 15 weeks. Both the cranial- and caudal-most vertebral bodies fused to form the basioccipital (occipital vertebrae 1-4) and sacrum (sacral vertebrae 1-5). In the sacrum, fusion of its so-called alar processes preceded that of the bodies by at least 6 weeks. In conclusion, the highly ordered and substantial changes in shape of the vertebral bodies leading to the formation of the vertebral canal make the development of the spine an excellent, continuous staging system for the (human) embryo between 6 and 10 weeks of development. © 2017 Anatomical Society.

A retrospective case-control analysis of the outpatient expenditures for western medicine and dental treatment modalities in CKD patients in Taiwan.

PubMed

Huang, Ren-Yeong; Lin, Yuh-Feng; Kao, Sen-Yeong; Shieh, Yi-Shing; Chen, Jin-Shuen

2014-01-01

To determine if expenditures for dentistry (DENT) correlate with severity of chronic kidney disease (CKD). A total of 10,457 subjects were enrolled from January 2008 to December 2010, divided into three groups: healthy control (HC) group (n = 1,438), high risk (HR) group (n = 3,392), and CKD group (n = 5,627). Five stages were further categorized for the CKD group. OPD utilization and expenditures for western medicine (WM), DENT, and TCM (traditional Chinese medicine) were analyzed retrospectively (2000-2008) using Taiwan's National Health Insurance Research Database. Three major areas were analyzed among groups CKD, HR and HC in this study: 1) demographic data and medical history; 2) utilization (visits/person/year) and expenditures (9-year cumulative expenditure, expenditure/person/year) for OPD services in WM, DENT, and TCM; and 3) utilization and expenditures for dental OPD services, particularly in dental filling, root canal and periodontal therapy. OPD utilization and expenditures of WM increased significantly for the CKD group compared with the HR and HC groups, and increased steadily along with the severity of CKD stages. However, overall DENT and TCM utilization and expenditures did not increase for the CKD group. In comparison among different CKD stages, the average expenditures and utilization for DENT including restorative filling and periodontal therapy, but not root canal therapy, showed significant decreases according to severity of CKD stage, indicating less DENT OPD utilization with progression of CKD. Patients with advanced CKD used DENT OPD service less frequently. However, the connection between CKD and DENT service utilization requires further study.

Comparative Analysis of Crack Propagation in Roots with Hand and Rotary Instrumentation of the Root Canal -An Ex-vivo Study.

PubMed

Kumari, Manju Raj; Krishnaswamy, Manjunath Mysore

2016-07-01

Success of any endodontic treatment depends on strict adherence to 'endodontic triad'. Preparation of root canal system is recognized as being one of the most important stages in root canal treatment. At times, we inevitably end up damaging root dentin which becomes a Gateway for infections like perforation, zipping, dentinal cracks and minute intricate fractures or even vertical root fractures, thereby resulting in failure of treatment. Several factors may be responsible for the formation of dentinal cracks like high concentration of sodium hypochlorite, compaction methods and various canal shaping methods. To compare and evaluate the effects of root canal preparation techniques and instrumentation length on the development of apical root cracks. Seventy extracted premolars with straight roots were mounted on resin blocks with simulated periodontal ligaments, exposing 1-2 mm of the apex followed by sectioning of 1mm of root tip for better visualization under stereomicroscope. The teeth were divided into seven groups of 10 teeth each - a control group and six experimental groups. Subgroup A & B were instrumented with: Stainless Steel hand files (SS) up to Root Canal Length (RCL) & (RCL -1 mm) respectively; sub group C & D were instrumented using ProTaper Universal (PTU) up to RCL and (RCL -1mm) respectively; subgroup E & F were instrumented using ProTaper Next (PTN) up to RCL & (RCL -1 mm) respectively. Stereomicroscopic images of the instrumentation sequence were compared for each tooth. The data was analyzed statistically using descriptive analysis by 'Phi' and 'Cramers' test to find out statistical significance between the groups. The level of significance was set at p< 0.05 using SPSS software. Stainless steel hand file group showed most cracks followed by ProTaper Universal & ProTaper Next though statistically not significant. Samples instrumented up to 1mm short of working length (RCL-1mm) showed lesser number of cracks. All groups showed cracks formation, the stainless steel group being the highest. Working 1mm short of apex reduces the incidence of crack formation.

The impact of anaemia on treatment outcome in patients with squamous cell carcinoma of anal canal and anal margin

PubMed Central

Cesnjevar, Monika; Anzic, Mitja; Hadzic, Jasna But; Ermenc, Ajra Secerov; Anderluh, Franc; Velenik, Vaneja; Jeromen, Ana; Korosec, Peter

2016-01-01

Background Radiochemotherapy is the main treatment for patients with squamous cell carcinoma of the anal canal. Anaemia is reported to have adverse effect on survival in cancer patients. The aim of the study was to evaluate the influence of anaemia on radiochemotherapy treatment outcome in patients with squamous cell carcinoma of the anal canal. Patients and methods One hundred consecutive patients with histologically confirmed squamous cell carcinoma of the anal canal were treated radically with 3-dimensional conformal or intensity-modulated radiation therapy followed by brachytherapy or external beam radiotherapy boost and with concurrent mitomycin C and 5-fluorouracil. The influence on survival of pre-treatment, mean on-treatment and end-of-treatment haemoglobin (Hb) concentrations was studied. Results The 5-year locoregional control, disease free survival, disease specific survival and overall survival rates for all patients were 72%, 71%, 77% and 62%, respectively. In univariate analysis, patients with pre-treatment and end-of-treatment Hb > 120 g/L survived statistically significantly better compared to patients with Hb ≤ 120 g/L. Patients with mean on-treatment Hb > 120 g/L only had statistically significant better locoregional control and overall survival than patients with Hb ≤ 120 g/L. In multivariate analysis, independent prognostic factors were pre-treatment Hb (> 120 g/L vs. ≤ 120 g/L) for overall survival (hazard ratio [HR] = 0.419, 95% confidence interval [CI] = 0.190–0.927, p = 0.032) and stage (I & II vs. III) for disease specific (HR = 3.523, 95% CI = 1.375–9.026, p = 0.009) and overall survival (HR = 2.230, 95% CI = 1.167–4.264, p = 0.015). Conclusions The pre-treatment, mean on-treatment and end-of-treatment Hb concentration > 120 g/L carried better prognosis for patients for with squamous cell carcinoma of the anal canal treated with radiochemotherapy. The pre-treatment Hb > 120 g/L was an independent prognostic factor for overall survival of patients with anal canal cancer. PMID:27069457

[Morphology of III stage larvae of Angiostrongylus cantonensis in Pomacea canaliculata].

PubMed

Zhang, Chao-Wei; Zhou, Xiao-Nong; Lv, Shan; Zhang, Yi; Liu, He-Xiang

2008-06-30

To observe the morphologic characteristics of III stage larvae of Angiostrongylus cantonensis from Pomacea canaliculata. P. canaliculata, the intermediate host snail of A. cantonensis, was infected with I stage larvae of A. cantonensis in laboratory. After 61 days, III stage larvae of A. cantonensis were harvested from snail's lungs and muscle of head-foot, followed by HE stain to observe morphological characteristics. The whole body of III stage larva was curling with obtuse head. Its pharyngeal canal extends from the buccal hole on the top of the head to the intestines at the pharyngeal intestine joint place, with apex cauda and clear anal tube. The tegument of the III stage larva was eosin-stained, with a transparent sheath outside of tegument. Some of the larvae cauda showed in circular cylinder, and some larvae presented ventral gland with two very short uterine which used to be the feature only showed in early IV stage larva. Morphologically characteristics of the III stage larvae is helpful to better understand the life-cycle and the control of A. cantonensis.

Environmental characteristics of the Mandovi-Zuari estuarine system in Goa

NASA Astrophysics Data System (ADS)

Qasim, S. Z.; Sen Gupta, R.

1981-11-01

Two rivers, the Mandovi and the Zuari, with their interconnecting canal, form an estuarine system in Goa on the west coast of India. Physical, chemical and biological features of this estuary are adapted to a seasonal rhythm induced by the annual cycle of the monsoon. Heavy precipitation and land runoff from June to September bring about large changes in temperature, salinity, flow pattern, dissolved oxygen and nutrients when the estuary becomes freshwater dominated. The monsoon season (July-September) is followed by a recovery period during the post-monsoon season (October-January) and thereafter a stable period of the pre-monsoon season (February-May) when the estuary becomes marine dominated. During the pre-monsoon (dry) season, the water in the estuarine system remains well mixed and the intrusion of salt water is felt as far as 65 km upstream in both the rivers; but during the monsoon season the rivers become stratified and a salt wedge is formed in each river which extends up to about 10 km upstream in the Mandovi and 12 km in the Zuari. The flow of the estuarine system is regulated by the entry of seawater with the incoming tide through Zuari which reaches Mandovi through the canal. The flow is reversed during the outgoing tide when the estuarine system is flushed. Dilution factors in both the estuaries are similar and vary from 1·2 to 8; highest values occur during the pre-monsoon season. Two shoals/sand bars occur permanently in Mandovi (Aguada Bay) close to a ramp-like inlet to the sea. This inlet poses no navigational problems for about 9 months during the dry season; but for a 3-month period during the monsoon, the waterway becomes hazardous and is closed to boat traffic. Heavy swell and intense wave activity lead to the transfer of sediments into the navigational inlet and the calm season brings the materials back to their original position with practically no overall change in the bathymetry of the bay. The oxygen cycle in the estuarine system is closely related to seasonal changes in temperature and bears an inverse relationship with salinity. In both the estuaries, the sulphate/chlorinity relationship remains uniform and similar to that of the sea except during the monsoon months when the relationship gets disturbed. Changes in phosphorus, nitrogen and silicon are largely regulated by rainfall and land runoff. There is no significant difference in the phytoplankton counts between Mandovi and Zuari which follow a rhythm similar to that of nitrate. Zooplankton biomass is higher in Zuari because of its greater marine influence. No seasonal variation was observed in the density of microflora in the two rivers. Bacterial counts were higher in the lower reaches of the estuarine system and decreased upstream. From its environmental features, the estuarine system can be classified as a tide-dominated coastal plain estuary.

Shock-turbulence interaction in core-collapse supernovae

NASA Astrophysics Data System (ADS)

Abdikamalov, Ernazar; Zhaksylykov, Azamat; Radice, David; Berdibek, Shapagat

2016-10-01

Nuclear shell burning in the final stages of the lives of massive stars is accompanied by strong turbulent convection. The resulting fluctuations aid supernova explosion by amplifying the non-radial flow in the post-shock region. In this work, we investigate the physical mechanism behind this amplification using a linear perturbation theory. We model the shock wave as a one-dimensional planar discontinuity and consider its interaction with vorticity and entropy perturbations in the upstream flow. We find that, as the perturbations cross the shock, their total turbulent kinetic energy is amplified by a factor of ˜2, while the average linear size of turbulent eddies decreases by about the same factor. These values are not sensitive to the parameters of the upstream turbulence and the nuclear dissociation efficiency at the shock. Finally, we discuss the implication of our results for the supernova explosion mechanism. We show that the upstream perturbations can decrease the critical neutrino luminosity for producing explosion by several per cent.

Single-stage evaluation of highly-loaded high-Mach-number compressor stages 5. Data and performance of baseline, corner-blow wall suction and combined corner blow wall suction stator

NASA Technical Reports Server (NTRS)

Nikkanen, J. P.; Brooky, J. P.

1972-01-01

A single-stage compressor with a rotor tip speed of 1600 ft/sec and a 0.5 hub tip ratio was used to investigate the effects of several stator endwall treatment methods on stage range and performance. These endwall treatment methods consisted of stator corner-blow, annular wall suction upstream of stator leading edge, and combined corner-blow and annular wall suction. The overall stage performance with corner blow was essentially the same as the baseline performance. The performance for the annular wall suction and the combined corner-blow and wall suction showed a reduction in peak efficiency of 2.5 percentage points compared to the baseline data.

Purifying fluoride-contaminated water by a novel forward osmosis design with enhanced flux under reduced concentration polarization.

PubMed

Pal, Madhubonti; Chakrabortty, Sankha; Pal, Parimal; Linnanen, Lassi

2015-08-01

For purifying fluoride-contaminated water, a new forward osmosis scheme in horizontal flat-sheet cross flow module was designed and investigated. Effects of pressure, cross flow rate, draw solution and alignment of membrane module on separation and flux were studied. Concentration polarization and reverse salt diffusion got significantly reduced in the new hydrodynamic regime. This resulted in less membrane fouling, better solute separation and higher pure water flux than in a conventional module. The entire scheme was completed in two stages-an upstream forward osmosis for separating pure water from contaminated water and a downstream nanofiltration operation for continuous recovery and recycle of draw solute. Synchronization of these two stages of operation resulted in a continuous, steady-state process. From a set of commercial membranes, two polyamide composite membranes were screened out for the upstream and downstream filtrations. A 0.3-M NaCl solution was found to be the best one for forward osmosis draw solution. Potable water with less than 1% residual fluoride could be produced at a high flux of 60-62 L m(-2) h(-1) whereas more than 99% draw solute could be recovered and recycled in the downstream nanofiltration stage from where flux was 62-65 L m(-2) h(-1).

Analysis of C. elegans VIG-1 expression.

PubMed

Shin, Kyoung-Hwa; Choi, Boram; Park, Yang-Seo; Cho, Nam Jeong

2008-12-31

Double-stranded RNA (dsRNA) induces gene silencing in a sequence-specific manner by a process known as RNA interference (RNAi). The RNA-induced silencing complex (RISC) is a multi-subunit ribonucleoprotein complex that plays a key role in RNAi. VIG (Vasa intronic gene) has been identified as a component of Drosophila RISC; however, the role VIG plays in regulating RNAi is poorly understood. Here, we examined the spatial and temporal expression patterns of VIG-1, the C. elegans ortholog of Drosophila VIG, using a vig-1::gfp fusion construct. This construct contains the 908-bp region immediately upstream of vig-1 gene translation initiation site. Analysis by confocal microscopy demonstrated GFP-VIG-1 expression in a number of tissues including the pharynx, body wall muscle, hypodermis, intestine, reproductive system, and nervous system at the larval and adult stages. Furthermore, western blot analysis showed that VIG-1 is present in each developmental stage examined. To investigate regulatory sequences for vig-1 gene expression, we generated constructs containing deletions in the upstream region. It was determined that the GFP expression pattern of a deletion construct (delta-908 to -597) was generally similar to that of the non-deletion construct. In contrast, removal of a larger segment (delta-908 to -191) resulted in the loss of GFP expression in most cell types. Collectively, these results indicate that the 406-bp upstream region (-596 to -191) contains essential regulatory sequences required for VIG-1 expression.

Measurement of airfoil heat transfer coefficients on a turbine stage

NASA Technical Reports Server (NTRS)

Dring, R. P.; Blair, M. F.

1984-01-01

The primary basis for heat transfer analysis of turbine airfoils is experimental data obtained in linear cascades. A detailed set of heat transfer coefficients was obtained along the midspan of a stator and a rotor in a rotating turbine stage. The data are to be compared to standard analyses of blade boundary layer heat transfer. A detailed set of heat transfer coefficients was obtained along the midspan of a stator located in the wake of a full upstream turbine stage. Two levels of inlet turbulence (1 and 10 percent) were used. The analytical capability will be examined to improve prediction of the experimental data.

Comparative Evaluation of Physical Surface Changes and Incidence of Separation in Rotary Nickel-Titanium Instruments: An in Vitro SEM Study

PubMed Central

Kaul, Rudra; Farooq, Riyaz; Kaul, Vibhuti; Khateeb, Shafayat Ullah; Purra, Aamir Rashid; Mahajan, Roopali

2014-01-01

Introduction: The aim of the present study was to comparatively evaluate the physical surface changes and incidence of separation in rotary nickel-titanium (NiTi) instruments using scanning electron microscope (SEM). Methods and Materials: A total number of 210 freshly extracted human maxillary and mandibular first molars were selected and distributed between three groups. Three different systems of rotary NiTi instruments, namely ProFile (PF), RaCe (RC) and Twisted File (TF), were used to prepare the canals using crown-down technique. All instruments were evaluated by means of SEM with 500× and 1500× magnifications, at four different stages; before use, after preparation of 7 and 14 canals and after instrument separation. Photomicrographs were also taken. The data was analyzed using the Kruskal-Wallis test and the level of significance was set at 0.001. It was found that H (HAT matrix) was 15.316 with 2 degrees of freedom. Moreover the various groups were compared using the Student-Newman-Keuls test with P<0.05 and it was found that all groups were significantly different. Results: RC showed the maximum wear of the surface followed by TF (P<0.05). PF showed the minimum wear except for its tip. There was no correlation between electropolishing and file fracture. Insignificant difference was observed in the mean number of canals shaped by PF and TF before their separation. Conclusion: Clinically, TF performance was superior, followed by PF then RC. RC fracture rate was the greatest after preparing the least number of canals. PMID:25031595

Study of the areas and thicknesses of mesiobucal root canals prepared by three endodontic techniques.

PubMed

Constante, Isa Geralda Teixeira; Davidowicz, Harry; Barletta, Fernando Branco; de Moura, Abilio Albuquerque Maranhão

2007-01-01

The purpose of this study was to compare, in vitro, by means of computerized analysis of digital radiographic images, the anatomic alterations produced in the mandibular molar tooth dentinal walls of mesiobucal canals with severe curvature by three different endodontic techniques: Progressive Preparation, Staged and Serial Preparation. A selection was made of 45 extracted, human, mandibular molars, with root curvatures greater than 25 degrees. They were divided into three groups for every technique studied, which were then sub-divided into three sub-groups in accordance with the position of the curvature along the root: cervical, median or apical. After access surgery and tooth length determination, the canals were filled with 100% Barium Sulphate radiological contrast and the teeth were then radiographed with a direct digital radiography system, using a special apparatus capable of keeping the samples in the same spatial position during the different radiographic takes. After the above-mentioned endodontic techniques had been performed, the teeth were again filled with Barium sulphate and were also radiographed under the same previously mentioned conditions. The pre- and post-operative digital images were then analyzed in two computerized programs, AutoCAD 2004 and CorelDraw 10, to assess, respectively, the areas and the horizontal alterations which occurred in the internal and external walls of the root canals. The results indicated that although no significant differences among the techniques were shown in the statistical analysis, in a descriptive analysis the Progressive Preparation technique was shown to be more regular, uniform and effective.

Thermally integrated staged methanol reformer and method

DOEpatents

Skala, Glenn William; Hart-Predmore, David James; Pettit, William Henry; Borup, Rodney Lynn

2001-01-01

A thermally integrated two-stage methanol reformer including a heat exchanger and first and second reactors colocated in a common housing in which a gaseous heat transfer medium circulates to carry heat from the heat exchanger into the reactors. The heat transfer medium comprises principally hydrogen, carbon dioxide, methanol vapor and water vapor formed in a first stage reforming reaction. A small portion of the circulating heat transfer medium is drawn off and reacted in a second stage reforming reaction which substantially completes the reaction of the methanol and water remaining in the drawn-off portion. Preferably, a PrOx reactor will be included in the housing upstream of the heat exchanger to supplement the heat provided by the heat exchanger.

An Eco-hydrologic Assessment of Small Experimental Catchments with Various Land Uses within the Panama Canal Watershed: Agua Salud Project

NASA Astrophysics Data System (ADS)

Crouch, T. D.; Ogden, F. L.; Stallard, R. F.; Smithsonian Tropical Research Institute, Panama Canal Watershed Experiment, Agua Salud Project

2010-12-01

Hydrological processes in the humid tropics are poorly understood and an important topic when it comes to water management in the seasonal tropics. The Smithsonian Tropical Research Institute, Panama Canal Watershed Experiment, Agua Salud Project, seeks to understand these processes and quantify the long-term effects of different land cover and uses across the Panama Canal Watershed. One of the project’s main objectives is to understand how reforestation effects seasonal stream flows. To meet this objective, a baseline characterization of hydrology on the small catchment scale is being assessed across different land uses typical in rural Panama. The small experimental catchments are found within Panama’s protected Soberania National Park and the adjacent headwaters of the Agua Salud and Mendoza Rivers, all of which are part of the greater Panama Canal Watershed. The land uses being monitored include a variety of control catchments as well as treated pasture sites. The catchments used for this study include a mature old regrowth forest, a 50% deforested or mosaic regrowth site, an active pasture and a monoculture invasive grass site (saccharum spontaneum) as experimental controls and two treated catchments that were recently abandoned pastures converted to teak and native species timber plantations. Installed instrumentation includes a network of rain gauges, v-notched weirs, atmometers, an eddy covariance system and an assortment of meteorological and automated geochemical sampling systems. Spatial, rainfall, runoff and ET data across these six geologically and topographically similar catchments are available from 2009 and 2010. Classic water balance and paired catchment techniques were used to compare the catchments on an annual, seasonal, and event basis. This study sets the stage for hydrologic modeling and for better understanding the effects of vegetation and land-use history on rainfall-runoff processes for the Agua Salud Project and Panama Canal Watershed Experiment.

The diagnosis and conservative treatment of a complex type 3 dens invaginatus using cone beam computed tomography (CBCT) and 3D plastic models.

PubMed

Kfir, A; Telishevsky-Strauss, Y; Leitner, A; Metzger, Z

2013-03-01

To investigate the use of 3D plastic models, printed from cone beam computed tomography (CBCT) data, for accurate diagnosis and conservative treatment of a complex case of dens invaginatus. A chronic apical abscess with a draining sinus tract was diagnosed during the treatment planning stage of orthodontic therapy. Radiographic examination revealed a large radiolucent area associated with an invaginated right maxillary central incisor, which was found to contain a vital pulp. The affected tooth was strategic in the dental arch. Conventional periapical radiographs provided only partial information about the invagination and its relationship with the main root canal and with the periapical tissues. A limited-volume CBCT scan of the maxilla did not show evidence of communication between the infected invagination and the pulp in the main root canal, which could explain the pulp vitality. A novel method was adopted to allow for instrumentation, disinfection and filling of the invagination, without compromising the vitality of the pulp in the complex root canal system. The CBCT data were used to produce precise 3D plastic models of the tooth. These models facilitated the treatment planning process and the trial of treatment approaches. This approach allowed the vitality of the pulp to be maintained in the complex root canal space of the main root canal whilst enabling the healing of the periapical tissues. Even when extensive periapical pathosis is associated with a tooth with type III dens invaginatus, pulp sensibility tests should be performed. CBCT is a diagnostic tool that may allow for the management of such teeth with complex anatomy. 3D printed plastic models may be a valuable aid in the process of assessing and planning effective treatment modalities and practicing them ex vivo before actually performing the clinical procedure. Unconventional technological approaches may be required for detailed treatment planning of complex cases of dens invaginatus. © 2012 International Endodontic Journal. Published by Blackwell Publishing Ltd.

Moving Domain Computational Fluid Dynamics to Interface with an Embryonic Model of Cardiac Morphogenesis

PubMed Central

Lee, Juhyun; Moghadam, Mahdi Esmaily; Kung, Ethan; Cao, Hung; Beebe, Tyler; Miller, Yury; Roman, Beth L.; Lien, Ching-Ling; Chi, Neil C.; Marsden, Alison L.; Hsiai, Tzung K.

2013-01-01

Peristaltic contraction of the embryonic heart tube produces time- and spatial-varying wall shear stress (WSS) and pressure gradients (∇P) across the atrioventricular (AV) canal. Zebrafish (Danio rerio) are a genetically tractable system to investigate cardiac morphogenesis. The use of Tg(fli1a:EGFP)y1 transgenic embryos allowed for delineation and two-dimensional reconstruction of the endocardium. This time-varying wall motion was then prescribed in a two-dimensional moving domain computational fluid dynamics (CFD) model, providing new insights into spatial and temporal variations in WSS and ∇P during cardiac development. The CFD simulations were validated with particle image velocimetry (PIV) across the atrioventricular (AV) canal, revealing an increase in both velocities and heart rates, but a decrease in the duration of atrial systole from early to later stages. At 20-30 hours post fertilization (hpf), simulation results revealed bidirectional WSS across the AV canal in the heart tube in response to peristaltic motion of the wall. At 40-50 hpf, the tube structure undergoes cardiac looping, accompanied by a nearly 3-fold increase in WSS magnitude. At 110-120 hpf, distinct AV valve, atrium, ventricle, and bulbus arteriosus form, accompanied by incremental increases in both WSS magnitude and ∇P, but a decrease in bi-directional flow. Laminar flow develops across the AV canal at 20-30 hpf, and persists at 110-120 hpf. Reynolds numbers at the AV canal increase from 0.07±0.03 at 20-30 hpf to 0.23±0.07 at 110-120 hpf (p< 0.05, n=6), whereas Womersley numbers remain relatively unchanged from 0.11 to 0.13. Our moving domain simulations highlights hemodynamic changes in relation to cardiac morphogenesis; thereby, providing a 2-D quantitative approach to complement imaging analysis. PMID:24009714

Method and apparatus for advanced staged combustion utilizing forced internal recirculation

DOEpatents

Rabovitser, Iosif K.; Knight, Richard A.; Cygan, David F.; Nester, Serguei; Abbasi, Hamid A.

2003-12-16

A method and apparatus for combustion of a fuel in which a first-stage fuel and a first-stage oxidant are introduced into a combustion chamber and ignited, forming a primary combustion zone. At least about 5% of the total heat output produced by combustion of the first-stage fuel and the first-stage oxidant is removed from the primary combustion zone, forming cooled first-stage combustion products. A portion of the cooled first-stage combustion products from a downstream region of the primary combustion zone is recirculated to an upstream region of primary combustion zone. A second-stage fuel is introduced into the combustion chamber downstream of the primary combustion zone and ignited, forming a secondary combustion zone. At least about 5% of the heat from the secondary combustion zone is removed. In accordance with one embodiment, a third-stage oxidant is introduced into the combustion chamber downstream of the secondary combustion zone, forming a tertiary combustion zone.

Life state response to environmental crisis: the case of the Love Canal, Niagara Falls, New York

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masters, S.K.

1986-01-01

This thesis explored the differences between two life stages - young and old - in perceiving and responding to man-made environmental disaster, as well as the support resources utilized to cope with disaster - personal, familial/friendship, and organizational. Because of the characteristics of man-made environmental disaster, and because of the different conditions of life and constructions of reality of older and younger families, it was expected that definitions of the situation would vary by life stage and locus of control - authoritative and personal. The research took place in the Love Canal neighborhood of Niagara Falls, New York. Fifty-eight familiesmore » were interviewed in the fall of 1978, and thirty-nine of these families were reinterviewed in the spring of 1979. Interviews were tape recorded, transcribed, and coded. The data were presented in contingency tables and interview excerpts. The interview schedules elicited information of perception of impact, responses to impact, and the utilization of support resources. In an authoritative locus of control situation, the major findings were that both older and younger families perceived impact, that older families were slightly less disrupted, that younger families relied on organizational and familial/friendship support resources, and that older families relied on familial/friendship support resources.« less

Calculation of pressure drop in the developmental stages of the medaka fish heart and microvasculature

NASA Astrophysics Data System (ADS)

Chakraborty, Sreyashi; Vlachos, Pavlos

2016-11-01

Peristaltic contraction of the developing medaka fish heart produces temporally and spatially varying pressure drop across the atrioventricular (AV) canal. Blood flowing through the tail vessels experience a slug flow across the developmental stages. We have performed a series of live imaging experiments over 14 days post fertilization (dpf) of the medaka fish egg and cross-correlated the red blood cell (RBC) pattern intensities to obtain the two-dimensional velocity fields. Subsequently we have calculated the pressure field by integrating the pressure gradient in the momentum equation. Our calculations show that the pressure drop across the AV canal increases from 0.8mm Hg during 3dpf to 2.8 mm Hg during 14dpf. We have calculated the time-varying wall shear stress for the blood vessels by assuming a spatially constant velocity magnitude in each vessel. The calculated wall shear stress matches the wall shear stress sensed by human endothelial cells (10-12 dyne/sq. cm). The pressure drop per unit length of the vessel is obtained by doing a control volume analysis of flow in the caudal arteries and veins. The current results can be extended to investigate the effect of the fluid dynamic parameters on the vascular and cardiac morphogenesis.

Continuous measurements of water surface height and width along a 6.5km river reach for discharge algorithm development

NASA Astrophysics Data System (ADS)

Tuozzolo, S.; Durand, M. T.; Pavelsky, T.; Pentecost, J.

2015-12-01

The upcoming Surface Water and Ocean Topography (SWOT) satellite will provide measurements of river width and water surface elevation and slope along continuous swaths of world rivers. Understanding water surface slope and width dynamics in river reaches is important for both developing and validating discharge algorithms to be used on future SWOT data. We collected water surface elevation and river width data along a 6.5km stretch of the Olentangy River in Columbus, Ohio from October to December 2014. Continuous measurements of water surface height were supplemented with periodical river width measurements at twenty sites along the study reach. The water surface slope of the entire reach ranged from during 41.58 cm/km at baseflow to 45.31 cm/km after a storm event. The study reach was also broken into sub-reaches roughly 1km in length to study smaller scale slope dynamics. The furthest upstream sub-reaches are characterized by free-flowing riffle-pool sequences, while the furthest downstream sub-reaches were directly affected by two low-head dams. In the sub-reaches immediately upstream of each dam, baseflow slope is as low as 2 cm/km, while the furthest upstream free-flowing sub-reach has a baseflow slope of 100 cm/km. During high flow events the backwater effect of the dams was observed to propagate upstream: sub-reaches impounded by the dams had increased water surface slopes, while free flowing sub-reaches had decreased water surface slopes. During the largest observed flow event, a stage change of 0.40 m affected sub-reach slopes by as much as 30 cm/km. Further analysis will examine height-width relationships within the study reach and relate cross-sectional flow area to river stage. These relationships can be used in conjunction with slope data to estimate discharge using a modified Manning's equation, and are a core component of discharge algorithms being developed for the SWOT mission.

Distribution of spawning activity by anadromous fishes in an atlantic slope drainage after removal of a low-head dam

USGS Publications Warehouse

Burdick, S.M.; Hightower, J.E.

2006-01-01

In 1998, the Quaker Neck Dam was removed from the Neuse River near Goldsboro, North Carolina, restoring access to more than 120 km of potential main-stem spawning habitat and 1,488 km of potential tributary spawning habitat to anadromous fishes. We used plankton sampling and standardized electrofishing to examine the extent to which anadromous fishes utilized this restored spawning habitat in 2003 and 2004. Evidence of spawning activity was detected upstream of the former dam site for three anadromous species: American shad Alosa sapidissima, hickory shad A. mediocris, and striped bass Morone saxatilis. The percentages of eggs and larvae collected in the restored upstream habitat were greater in 2003, when spring flows were high, than in 2004. River reaches where spawning occurred were estimated from egg stage and water velocity data. Spawning of American shad and striped bass occurred primarily in main-stem river reaches that were further upstream during the year of higher spring flows. Hickory shad generally spawned in downstream reaches and in tributaries above and below the former dam site. These results demonstrate that anadromous fishes will take advantage of upper basin spawning habitat restored through dam removal as long as instream flows are adequate to facilitate upstream migration.

Generation of forerunner electron beam during interaction of ion beam pulse with plasma

DOE PAGES

Hara, Kentaro; Kaganovich, Igor D.; Startsev, Edward A.

2018-01-01

The long-time evolution of the two-stream instability of a cold tenuous ion beam pulse propagating through the background plasma with density much higher than the ion beam density is investigated using a large-scale one-dimensional electrostatic kinetic simulation. The three stages of the instability are investigated in detail. After the initial linear growth and saturation by the electron trapping, a portion of the initially trapped electrons becomes detrapped and moves ahead of the ion beam pulse forming a forerunner electron beam, which causes a secondary two-stream instability that preheats the upstream plasma electrons. Consequently, the self-consistent nonlinear-driven turbulent state is setmore » up at the head of the ion beam pulse with the saturated plasma wave sustained by the influx of the cold electrons from upstream of the beam that lasts until the final stage when the beam ions become trapped by the plasma wave. Finally, the beam ion trapping leads to the nonlinear heating of the beam ions that eventually extinguishes the instability.« less

Generation of forerunner electron beam during interaction of ion beam pulse with plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hara, Kentaro; Kaganovich, Igor D.; Startsev, Edward A.

The long-time evolution of the two-stream instability of a cold tenuous ion beam pulse propagating through the background plasma with density much higher than the ion beam density is investigated using a large-scale one-dimensional electrostatic kinetic simulation. The three stages of the instability are investigated in detail. After the initial linear growth and saturation by the electron trapping, a portion of the initially trapped electrons becomes detrapped and moves ahead of the ion beam pulse forming a forerunner electron beam, which causes a secondary two-stream instability that preheats the upstream plasma electrons. Consequently, the self-consistent nonlinear-driven turbulent state is setmore » up at the head of the ion beam pulse with the saturated plasma wave sustained by the influx of the cold electrons from upstream of the beam that lasts until the final stage when the beam ions become trapped by the plasma wave. Finally, the beam ion trapping leads to the nonlinear heating of the beam ions that eventually extinguishes the instability.« less

3. ELEVATION. FROM SOUTH WITH CANAL PRISM. Canal Road ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. ELEVATION. FROM SOUTH WITH CANAL PRISM. - Canal Road Bridge, Canal Road spanning Delaware Canal Diversion, Locks 22 & 23 in Delaware Canal State Park in Williams Township, Raubsville, Northampton County, PA

Mandibular first and second molars with three mesial canals: a case series

PubMed Central

Aminsobhani, Mohsen; Bolhari, Behnam; Shokouhinejad, Noushin; Ghorbanzadeh, Abdollah; Ghabraei, Sholeh; Rahmani, Mohamad Bagher

2010-01-01

Adequate cleaning, shaping and filling of the root canal system are mandatory for successful root canal treatment. Thorough knowledge of root canal morphology and unusual anatomy of the tooth is critical for the practitioner. The occurrence and location of the third mesial canal (Middle Mesial Canal) in mandibular first and second molars in relation to other two mesial canals that were treated in private practice were studied. In 27 clinical cases, the presence of a middle mesial canal was demonstrated. The third canal was located in the middle of the distance between the mesiobuccal and mesiolingual canals. This canal configuration was found in six second lower molars and twenty one first molars. Middle mesial canal in all of our cases joined to mesiobuccal or mesiolingual canals. None of the teeth consisted of three independent canals with three apical foramina. In conclusion, every attempt should be made to find and treat all root canals of a tooth. PMID:24778681

Stochastic resonance in the synaptic transmission between hair cells and vestibular primary afferents in development.

PubMed

Flores, A; Manilla, S; Huidobro, N; De la Torre-Valdovinos, B; Kristeva, R; Mendez-Balbuena, I; Galindo, F; Treviño, M; Manjarrez, E

2016-05-13

The stochastic resonance (SR) is a phenomenon of nonlinear systems in which the addition of an intermediate level of noise improves the response of such system. Although SR has been studied in isolated hair cells and in the bullfrog sacculus, the occurrence of this phenomenon in the vestibular system in development is unknown. The purpose of the present study was to explore for the existence of SR via natural mechanical-stimulation in the hair cell-vestibular primary afferent transmission. In vitro experiments were performed on the posterior semicircular canal of the chicken inner ear during development. Our experiments showed that the signal-to-noise ratio of the afferent multiunit activity from E15 to P5 stages of development exhibited the SR phenomenon, which was characterized by an inverted U-like response as a function of the input noise level. The inverted U-like graphs of SR acquired their higher amplitude after the post-hatching stage of development. Blockage of the synaptic transmission with selective antagonists of the NMDA and AMPA/Kainate receptors abolished the SR of the afferent multiunit activity. Furthermore, computer simulations on a model of the hair cell - primary afferent synapse qualitatively reproduced this SR behavior and provided a possible explanation of how and where the SR could occur. These results demonstrate that a particular level of mechanical noise on the semicircular canals can improve the performance of the vestibular system in their peripheral sensory processing even during embryonic stages of development. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Treatment and Prognosis of Squamous Cell Carcinoma of the External Auditory Canal and Middle Ear: A Multi-Institutional Retrospective Review of 87 Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogawa, Kazuhiko; Nakamura, Katsumasa; Hatano, Kazuo

Purpose: To examine the relative roles of surgery, radiotherapy, and chemotherapy in the management of patients with squamous cell carcinomas of the external auditory canal and middle ear. Methods and Materials: The records of 87 patients with histologically confirmed squamous cell carcinoma who were treated between 1984 and 2005 were reviewed. Fifty-three patients (61%) were treated with surgery and radiotherapy (S + RT group) and the remaining 34 patients with radiotherapy alone (RT group). Chemotherapy was administered in 34 patients (39%). Results: The 5-year actuarial overall and disease-free survival (DFS) rates for all patients were 55% and 54%, respectively. Onmore » univariate analysis, T stage (Stell's classification), treatment modality, and Karnofsky performance status had significant impact on DFS. On multivariate analysis, T stage and treatment modality were significant prognostic factors. Chemotherapy did not influence DFS. The 5-year DFS rate in T1, T2, and T3 patients was 83%, 45%, and 0 in the RT group (p < 0.0001) and 75%, 75%, and 46% in the S + RT group (p = 0.13), respectively. The 5-year DFS rate in patients with negative surgical margins, those with positive margins, and those with macroscopic residual disease was 83%, 55%, and 38%, respectively (p = 0.007). Conclusions: Radical radiotherapy is the treatment of choice for early-stage (T1) diseases, whereas surgery (negative surgical margins if possible) with radiotherapy is recommended as the standard care for advanced (T2-3) disease. Further clarification on the role of chemotherapy is necessary.« less

Spatial orientation of semicircular canals and afferent sensitivity vectors in pigeons

NASA Technical Reports Server (NTRS)

Dickman, J. D.

1996-01-01

Rotational head motion in vertebrates is detected by the semicircular canal system, whose innervating primary afferent fibers carry information about movement in specific head planes. The semicircular canals have been qualitatively examined over a number of years, and the canal planes have been quantitatively characterized in several animal species. The present study first determined the geometric relationship between individual semicircular canals and between the canals and the stereotactic head planes in pigeons. Stereotactic measurements of multiple points along the circumference of the bony canals were taken, and the measured points fitted with a three-dimensional planar surface. Direction normals to the plane's surface were calculated and used to define angles between semicircular canal pairs. Because of the unusual shape of the anterior semicircular canals in pigeons, two planes, a major and a minor, were fitted to the canal's course. Calculated angle values for all canals indicated that the horizontal and posterior semicircular canals are nearly orthogonal, but the anterior canals have substantial deviations from orthogonality with other canal planes. Next, the responses of the afferent fibers that innervate each of the semicircular canals to 0.5 Hz sinusoidal rotation about an earth-vertical axis were obtained. The head orientation relative to the rotation axis was systematically varied so that directions of maximum sensitivity for each canal afferent could be determined. These sensitivity vectors were then compared with the canal plane direction normals. The afferents that innervated specific semicircular canals formed homogeneous clusters of sensitivity vectors in different head planes. The horizontal and posterior afferents had average sensitivity vectors that were largely co-incident with the innervated canal plane direction normals. Anterior canal afferents, however, appeared to synthesize contributions from the major and minor plane components of the bony canal structure to produce a resultant sensitivity vector that was positioned between the canal planes. Calculated angles between the average canal afferent sensitivity vectors revealed that direction orthogonality is preserved at the afferent signal level, even though deviations from canal plane orthogonality exist.

Relations between total phosphorus and orthophosphorus concentrations and rainfall, surface-water discharge, and groundwater levels in Big Cypress Seminole Indian Reservation, Florida, 2014–16

USGS Publications Warehouse

McBride, W. Scott; Sifuentes, Dorothy F.

2018-02-06

The Seminole Tribe of Florida (the Tribe) is partnering with the U.S. Environmental Protection Agency to develop a numeric phosphorus criterion for the 52,000-acre Big Cypress Seminole Indian Reservation (BCSIR), which is located downgradient of the Everglades Agricultural Area, and of other public and private lands, in southeastern Hendry County and northwestern Broward County in southern Florida. The U.S. Geological Survey (USGS), in cooperation with the Tribe, used water-quality data collected between October 2014 and September 2016 by the Tribe and the South Florida Water Management District (SFWMD), along with data from rainfall gages, surface-water stage and discharge gages, and groundwater monitoring wells, to (1) examine the relations between local hydrology and measured total phosphorus (TP) and orthophosphorus (OP) concentrations and (2) identify explanatory variables for TP concentrations. Of particular concern were conditions when TP exceeded 10 parts per billion (ppb) (0.01 milligram per liter [mg/L]) given that the State of Florida and the Miccosukee Tribe of Indians Alligator Alley Reservation (located downstream of the BCSIR) have adopted a 10-ppb maximum TP criterion for surface waters.From October 2014 to September 2016, the Tribe collected 47–52 samples at each of nine water-quality sites for analysis of TP and OP, except at one site where 28 samples were collected. For all sites sampled, concentrations of TP (as phosphorus [P]) ranged from less than 0.002 mg/L (2 ppb) to a maximum of nearly 0.50 mg/L (500 ppb), whereas concentrations of OP (as P), the reactive form of inorganic phosphorus readily absorbed by plants and (or) abiotically absorbed, ranged from less than 0.003 mg/L (3 ppb) to a maximum of 0.24 mg/L (240 ppb). The median and interquartile ranges of concentrations of TP and OP in the samples collected in 2014–16 by the Tribe were similar to the median and interquartile ranges of concentrations in samples collected by the SFWMD at nearby sites during the same period. Differences in concentrations can likely be explained by differences in sample collection methods, sampling locations, sample collection time, and the hydrology during sampling or by the number of samples collected. A major limitation of this study was the short duration of sample collection, which covers a limited range of hydrologic conditions within the BCSIR.The effect of surface-water and groundwater hydrologic conditions on TP and OP concentrations was assessed by using rainfall data and surface-water stage and discharge records. The highest TP and OP concentrations occurred during peak surface-water flows in the canals following long dry periods. Concentrations of TP and OP increased internal to the BCSIR in the western half of the BCSIR during wet periods, but increased concentrations tended to lag behind rainfall events, likely because control structures upstream of sampling sites do not release flows until the water levels in the canals reach predetermined levels. This pattern may indicate that bed sediments in the canals contain high concentrations of phosphorus that becomes resuspended during high flows or that phosphorus salts that had accumulated on dry land during dry periods are carried into the canals by runoff. The largest TP spikes usually occurred at the beginning of high-flow events, but then quickly tapered off even when flows remained high.Groundwater flows were assessed in the BCSIR by using groundwater level observations from two preexisting USGS monitoring well clusters, each characterized by a shallow well installed in the surficial aquifer system and a deeper well installed in the intermediate aquifer system. Groundwater levels were evaluated with respect to surface-water levels and discharge in the BCSIR during the period of surface-water sampling. During dry conditions water levels in canals were often higher than groundwater levels in the surficial aquifer, indicating the potential for surface water to recharge the surficial aquifer. During wetter conditions, this trend reversed, and there was potential for shallow groundwater discharge into the canals.From October 2014 to September 2016, concentrations of TP tended to decrease as surface-water inflows moved across the BCSIR from north to south. In both the western and eastern halves of the reservation, the mean concentration of TP was lower in the surface-water outflows from the BCSIR than in the inflows. The mean concentration of TP in the inflows to the western reservation was 0.04 mg/L (40 ppb), whereas the mean concentration of TP in the outflows was 0.03 mg/L (30 ppb). In the eastern reservation, the mean concentration of TP in the inflows was 0.07 mg/L (70 ppb), whereas the mean concentration of TP in the outflows was 0.04 mg/L (40 ppb).TP and OP concentrations were evaluated relative to other water-quality parameters, including turbidity, suspended solids, nitrate plus nitrite, dissolved oxygen, pH, and specific conductance, to determine if any relations existed between TP and other variables. Weak relations were indicated for turbidity and suspended solids at two sites, which indicates that there may be a relation of increased TP to mobilization of sediment.

Transport across Schlemm's canal endothelium and the blood-aqueous barrier.

PubMed

Braakman, Sietse T; Moore, James E; Ethier, C Ross; Overby, Darryl R

2016-05-01

The majority of trabecular outflow likely crosses Schlemm's canal (SC) endothelium through micron-sized pores, and SC endothelium provides the only continuous cell layer between the anterior chamber and episcleral venous blood. SC endothelium must therefore be sufficiently porous to facilitate outflow, while also being sufficiently restrictive to preserve the blood-aqueous barrier and prevent blood and serum proteins from entering the eye. To understand how SC endothelium satisfies these apparently incompatible functions, we examined how the diameter and density of SC pores affects retrograde diffusion of serum proteins across SC endothelium, i.e. from SC lumen into the juxtacanalicular tissue (JCT). Opposing retrograde diffusion is anterograde bulk flow velocity of aqueous humor passing through pores, estimated to be approximately 5 mm/s. As a result of this relatively large through-pore velocity, a mass transport model predicts that upstream (JCT) concentrations of larger solutes such as albumin are less than 1% of the concentration in SC lumen. However, smaller solutes such as glucose are predicted to have nearly the same concentration in the JCT and SC. In the hypothetical case that, rather than micron-sized pores, SC formed 65 nm fenestrae, as commonly observed in other filtration-active endothelia, the predicted concentration of albumin in the JCT would increase to approximately 50% of that in SC. These results suggest that the size and density of SC pores may have developed to allow SC endothelium to maintain the blood-aqueous barrier while simultaneously facilitating aqueous humor outflow. Copyright © 2016 Elsevier Ltd. All rights reserved.

Performance of a 1.57 pressure-ratio transonic fan stage with a screen-induced 90 deg circumferential inlet flow distortion

NASA Technical Reports Server (NTRS)

Sanger, N. L.

1976-01-01

A transonic fan stage having a design pressure ratio of 1.57 was tested with a 90 degree circumferential distortion imposed on the inlet flow. The rotor diameter was approximately 50.8 cm, and the design pressure ratio was 1.60 at a tip speed of 425 m/sec. Overall performance at 70 and 100 percent of design speed showed a loss of stall pressure ratio and flow range at design speed and no significant loss in stall pressure ratio at 70 percent of design speed. Detailed flow measurements are presented to show the rotor-upstream flow interactions and the attenuation and amplification properties through the stage.

Inlet flow distortion in turbomachinery. I - Comparison of theory and experiment in a transonic fan stage. II - A parameter study

NASA Technical Reports Server (NTRS)

Seidel, B. S.; Matwey, M. D.; Adamczyk, J. J.

1980-01-01

In the present paper, a semi-actuator-disk theory is reviewed that was developed previously for the distorted inflow to a single-stage axial-flow compressor. Flow distortion occurs far upstream; it may be a distortion in stagnation temperature, stagnation pressure, or both. Losses, quasi-steady deviation angles, and reference incidence correlations are included in the analysis, and both subsonic and transonic relative Mach numbers are considered. The theory is compared with measurements made in a transonic fan stage, and a parameter study is carried out to determine the influence of solidity on the attenuation of distortions in stagnation pressure and stagnation temperature.

Neural differentiation of caudal cell mass (secondary neurulation) in chick embryos: Hamburger and Hamilton Stages 16-45.

PubMed

Yang, Hee-Jin; Wang, Kyu-Chang; Chi, Je G; Lee, Myung-Sook; Lee, Yun-Jin; Kim, Seung-Ki; Cho, Byung-Kyu

2003-04-14

In an attempt to understand the events in the secondary neurulation in embryonic stage, we investigated morphological changes in the tail bud of normal developing chick embryos. Hamburger and Hamilton stage 16-45 embryos were harvested and processed for light microscopic studies. The secondary neural tube is formed by aggregation of the caudal cell mass. Cells are arranged into a cord-like mass (medullary cord), which is continuous with the primary neural tube. Multiple small cavities develop in the medullary cord, and these cavities coalesce into one single lumen. The process of coalescence is completed by stage 35, and the whole neural tube is transformed into one tube with a single continuous lumen. At this stage, the terminal portion of the neural tube is bulged dorsally. Thereafter, the caudal portion of the neural tube regresses, and the proximal portion develops into normal spinal cord. Transient occlusion of the central canal was observed at stage 40 in one sample. The sequence of events elucidated in this study can be used as base-line data for experiments concerning congenital malformations involving secondary neurulation.

Influence of forest and rangeland management on anadromous fish habitat in Western North America: habitat requirements of anadromous salmonids.

Treesearch

D.W. Reiser; T.C. Bjornn

1979-01-01

Habitat requirements of anadromous and some resident salmonid fishes have been described for various life stages, including upstream migration of adults, spawning, incubation, and juvenile rearing. Factors important in the migration of adults are water temperature, minimum water depth, maximum water velocity, turbidity, dissolved oxygen, and...

Irrigant flow during photon-induced photoacoustic streaming (PIPS) using Particle Image Velocimetry (PIV).

PubMed

Koch, Jon D; Jaramillo, David E; DiVito, Enrico; Peters, Ove A

2016-03-01

This study aimed to compare fluid movements generated from photon-induced photoacoustic streaming (PIPS) and passive ultrasonic irrigation (PUI). Particle Image Velocimetry (PIV) was performed using 6-μm melamine spheres in water. Measurement areas were 3-mm-long sections of the canal in the coronal, midroot and apical regions for PIPS (erbium/yttrium-aluminium garnet (Er:YAG) laser set at 15 Hz with 20 mJ), or passive ultrasonic irrigation (PUI, non-cutting insert at 30% unit power) was performed in simulated root canals prepared to an apical size #30/0.04 taper. Fluid movement was analysed directly subjacent to the apical ends of ultrasonic insert or fiber optic tips as well as at midroot and apically. During PUI, measured average velocities were around 0.03 m/s in the immediate vicinity of the sides and tip of the ultrasonic file. Speeds decayed to non-measureable values at a distance of about 2 mm from the sides and tip. During PIPS, typical average speeds were about ten times higher than those measured for PUI, and they were measured throughout the length of the canal, at distances up to 20 mm away. PIPS caused higher average fluid speeds when compared to PUI, both close and distant from the instrument. The findings of this study could be relevant to the debriding and disinfecting stage of endodontic therapy. Irrigation enhancement beyond needle irrigation is relevant to more effectively eradicate microorganisms from root canal systems. PIPS may be an alternative approach due to its ability to create high streaming velocities further away from the activation source compared to ultrasonic activation.

Environmental pollution, chromosomes, and health

NASA Astrophysics Data System (ADS)

Bell, Peter M.

In mid-May, 1980, President Carter declared a state of emergency at the Love Canal area, near Niagara Falls, New York. The reason for this was for the U.S. to underwrite the relocation costs ($3-5 million) of some 2500 residents who, according to a report by the EPA (Environmental Protection Agency) may have suffered damaged chromosomes. These injuries were apparently caused by contact with toxic wastes that had been dumped in the area in the years prior to development for housing.That the toxic compounds exist in the Love Canal and Niagara Falls subsurface zones, including public water supplies, appears to be established fact. That the residents of the Love Canal area suffered chromosomal damage may be established fact as well. Whether or not these two findings can be linked to ill health of the residents is another matter. Recently, the EPA report has been described as having ‘close to zero scientific significance,’ and has been ‘discredited’(Science, 208, 123a, 1980). The reasons for this disparity go beyond differences of opinion, beyond possible inadequacies of the EPA study, and even beyond problems that probably will arise from future studies, including those now in the planning stages. The problem is that even if victims have easily recognizable injuries from toxic substances (injury that apparently has not occurred to Love Canal residents), medical science usually cannot show a causal relationship. Even chromosomal damage is, at best, difficult to interpret. In ideal studies of significant populations and control groups, the association of toxic chemical to chromosome damage and to cancer and birth defects is indirect and, up to now, has been shown to have little or no significance to an individual member of the exposed population.

2. CANAL BOAT ENTERING THE DELAWARE CANAL FROM OF THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. CANAL BOAT ENTERING THE DELAWARE CANAL FROM OF THE LEHIGH RIVER. BOATS COULD BE FERRIED ACROSS THE DELAWARE RIVER TO THE MORRIS CANAL BY A CABLE SUPPORTED TROLLEY. - Morris Canal, Phillipsburg, Warren County, NJ

Root Canal Morphology and Configuration of 118 Mandibular First Molars by Means of Micro-Computed Tomography: An Ex Vivo Study.

PubMed

Wolf, Thomas Gerhard; Paqué, Frank; Zeller, Maximilian; Willershausen, Brita; Briseño-Marroquín, Benjamín

2016-04-01

The aim of this study was to investigate the root canal system morphology of the mandibular first molar by means of micro-computed tomography. The root canal configuration, foramina, and accessory canals frequency of 118 mandibular first molars were investigated by means of micro-computed tomography and 3-dimensional software imaging. A 4-digit system describes the root canal configuration from the coronal to apical thirds and the main foramina number. The most frequent root canal configurations in mesial root were 2-2-2/2 (31.4%), 2-2-1/1 (15.3%), and 2-2-2/3 (11.9%); another 24 different root canal configurations were observed in this root. A 1-1-1/1 (58.5%), 1-1-1/2 (10.2%), and 16 other root canal configurations were observed in the distal root. The mesiobuccal root canal showed 1-4 foramina in 24.6%, and the mesiolingual showed 1-3 foramina in 28.0%. One connecting canal between the mesial root canals was observed in 30.5% and 2 in 3.4%. The distolingual root canal showed 1-4 foramina in 23.7%, whereas a foramen in the distobuccal root canal was rarely detected (3.4%). The mesiobuccal, mesiolingual, and distolingual root canals showed at least 1 accessory canal (14.3, 10.2, and 4.2%, respectively), but the distobuccal had none. The root canal configuration of mandibular first molars varies strongly. According to our expectations, both the mesial and distal roots showed a high number of morphologic diversifications. The root canal system of the mesial root showed more root canal configuration variations, connecting and accessory canals than the distal root. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Planer orientation of the bilateral semicircular canals in dizzy patients.

PubMed

Aoki, Sachiko; Takei, Yasuhiko; Suzuki, Kazufumi; Masukawa, Ai; Arai, Yasuko

2012-10-01

Recent development of 3-dimensional analysis of eye movement enabled to detect the eye rotation axis, which is used to determine the responsible semicircular canal(s) in dizzy patients. Therefore, the knowledge of anatomical orientation of bilateral semicircular canals is essential, as all 6 canals influence the eye movements. Employing the new head coordinate system suitable for MR imaging, we calculated the angles of semicircular canal planes of both ears in 11 dizzy patients who had normal caloric response in both ears. The angles between adjacent canal pairs were nearly perpendicular in both ears. The angle between the posterior canal planes and head sagittal plane was 51° and significantly larger the angle between the anterior canal planes and head sagittal plane, which was 35°. The angle between the horizontal canal plane and head sagittal plane was almost orthogonal. Pairs of contralateral synergistic canal planes were not parallel, forming 10° between right and left horizontal canal planes, 17° between right anterior and left posterior canal planes and 19° between the right posterior and left anterior canal planes. Our measurement of the angles of adjacent canal pairs and the angle between each semicircular canal and head sagittal plane coincided with those of previous reports obtained from CT images and skull specimens. However, the angles between contralateral synergistic canal planes were more parallel than those of previous reports. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Improving a stage forecasting Muskingum model by relating local stage and remote discharge

NASA Astrophysics Data System (ADS)

Barbetta, S.; Moramarco, T.; Melone, F.; Brocca, L.

2009-04-01

Following the parsimonious concept of parameters, simplified models for flood forecasting based only on flood routing have been developed for flood-prone sites located downstream of a gauged station and at a distance allowing an appropriate forecasting lead-time. In this context, the Muskingum model can be a useful tool. However, critical points in hydrological routing are the representation of lateral inflows contribution and the knowledge of stage-discharge relationships. As regards the former, O'Donnell (O'Donnell, T., 1985. A direct three-parameter Muskingum procedure incorporating lateral inflow, Hydrol. Sci. J., 30[4/12], 479-496) proposed a three-parameter Muskingum procedure assuming the lateral inflows proportional to the contribution entering upstream. Using this approach, Franchini and Lamberti (Franchini, M. & Lamberti, P., 1994. A flood routing Muskingum type simulation and forecasting model based on level data alone, Water Resour. Res., 30[7], 2183-2196) presented a simple model Muskingum type to provide forecast water levels at the downstream end by selecting a routing time interval and, hence, a forecasting lead-time allowing to express the forecast stage as a function of only observed quantities. Moramarco et al. (Moramarco, T., Barbetta, S., Melone, F. & Singh, V.P., 2006. A real-time stage Muskingum forecasting model for a site without rating curve, Hydrol. Sci. J., 51[1], 66-82) enhanced the modeling scheme incorporating a procedure for adapting the parameter linked to lateral inflows. This last model, called STAFOM (STAge FOrecasting Model), was also extended to a two connected river branches schematization in order to improve significantly the forecasting lead-time. The STAFOM model provided satisfactory results for most of the analysed flood events observed in different river reaches in the Upper-Middle Tiber River basin in Central Italy. However, the analysis highlighted that the stage forecast should be enhanced when sudden modifications occur in the upstream and downstream hydrographs recorded in real-time. Moramarco et al. (Moramarco, T., Barbetta, S., F. Melone, F. & Singh, V.P., 2005. Relating local stage and remote discharge with significant lateral inflow, J. Hydrol. Engng ASCE, 10[1], 58-69) showed that for any flood condition at ends of a river reach, a direct proportionality between the upstream and downstream mean velocity can be found. This insight was the basis for developing the Rating Curve Model (RCM) that allows to also accommodate significant lateral inflow contributions, permitting, without using a flood routing procedure and without the need of a rating curve at a local site, to relate the local hydraulic conditions with those at a remote gauged section. Therefore, to improve the STAFOM performance mainly for highly varying flood conditions, the model has been here modified by coupling it with a procedure based on the RCM approach. Several flood events occurred along different equipped river reaches of the Upper Tiber River basin have been used as case study. Results showed that the new model, named STAFOM-RCM, apart from to improve the stage forecast accuracy in terms of error on peak stage, Nash-Sutcliffe efficiency coefficient and the coefficient of persistence, allowed to use a larger lead time thus avoiding the two-river branches cascade schematization where fluctuations in stage forecasting occur more frequently.

27. VIEW OF TWIN FALLS MAIN CANAL HEADGATE WITH CANAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

27. VIEW OF TWIN FALLS MAIN CANAL HEADGATE WITH CANAL BRIDGE IN DISTANCE; LOOKING SOUTHWEST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

Transitions in early embryonic atrioventricular valvular function correspond with changes in cushion biomechanics that are predictable by tissue composition.

PubMed

Butcher, Jonathan T; McQuinn, Tim C; Sedmera, David; Turner, Debi; Markwald, Roger R

2007-05-25

Endocardial cushions are critical to maintain unidirectional blood flow under constantly increasing hemodynamic forces, but the interrelationship between endocardial cushion structure and the mechanics of atrioventricular junction function is poorly understood. Atrioventricular (AV) canal motions and blood velocities of embryonic chicks at Hamburger and Hamilton (HH) stages 17, 21, and 25 were quantified using ultrasonography. Similar to the embryonic zebrafish heart, the HH17 AV segment functions like a suction pump, with the cushions expanding in a wave during peak myocardial contraction and becoming undetectable during the relaxation phase. By HH25, the AV canal contributes almost nothing to the piston-like propulsion of blood, but the cushions function as stoppers apposing blood flow with near constant thickness. Using a custom built mesomechanical testing system, we quantified the nonlinear pseudoelastic biomechanics of developing AV cushions, and found that both AV cushions increased in effective modulus between HH17 and HH25. Enzymatic digestion of major structural constituent collagens or glycosaminoglycans resulted in distinctly different stress-strain curves suggestive of their individual contributions. Mixture theory using histologically determined volume fractions of cells, collagen, and glycosaminoglycans showed good prediction of cushion material properties regardless of stage and cushion position. These results have important implications in valvular development, as biomechanics may play a larger role in stimulating valvulogenic events than previously thought.

Premalignant Lesions of the Anal Canal and Squamous Cell Carcinoma of the Anal Canal

PubMed Central

Poggio, Juan Lucas

2011-01-01

Squamous cell carcinoma of the anus (SCCA) is a rare tumor. However, its incidence has been increasing in men and women over the past 25 years worldwide. Risk factors associated with this cancer are those behaviors that predispose individuals to human papillomavirus (HPV) infection and immunosuppression. Anal cancer is generally preceded by high-grade anal intraepithelial neoplasia (HGAIN), which is most prevalent in human immunodeficiency virus-positive men who have sex with men. High-risk patients may benefit from screening. The most common presentation is rectal bleeding, which is present in nearly 50% of patients. Twenty percent of patients have no symptoms at the time of presentation. Clinical staging of anal cancer requires a digital rectal exam and a positron emission tomography/computed tomography scan of the chest, abdomen, and pelvis. Endorectal/endoanal ultrasound appears to add more-specific staging information when compared with digital rectal examination alone. Treatment of anal cancer prior to the 1970s involved an abdominoperineal resection. However, the current standard of care for localized anal cancer is concurrent chemoradiation therapy, primarily because of its sphincter-saving and colostomy-sparing potential. Studies have addressed alternative chemoradiation regimens to improve the standard protocol of fluorouracil, misogynic, and radiation, but no alternative regimen has proven superior. Surgery is reserved for those patients with residual disease or recurrence. PMID:22942800

From lake to estuary, the tale of two waters: a study of aquatic continuum biogeochemistry.

PubMed

Julian, Paul; Osborne, Todd Z

2018-01-25

The balance of fresh and saline water is essential to estuarine ecosystem function. Along the fresh-brackish-saline water gradient within the C-43 canal/Caloosahatchee River Estuary (CRE), the quantity, timing and distribution of water, and associated water quality significantly influence ecosystem function. Long-term trends of water quality and quantity were assessed from Lake Okeechobee to the CRE between May 1978 and April 2016. Significant changes to monthly flow volumes were detected between the lake and the estuary which correspond to changes in upstream management. and climatic events. Across the 37-year period, total phosphorus (TP) flow-weighted mean (FWM) concentration significantly increased at the lake; meanwhile, total nitrogen (TN) FMW concentrations significantly declined at both the lake and estuary headwaters. Between May 1999 and April 2016, TN, TP, and total organic carbon (TOC), ortho-P, and ammonium conditions were assessed within the estuary at several monitoring locations. Generally, nutrient concentrations decreased from upstream to downstream with shifts in TN/TP from values > 20 in the freshwater portion, ~ 20 in the estuarine portion, and < 20 in the marine portion indicating a spatial shift in nutrient limitations along the continuum. Aquatic productivity analysis suggests that the estuary is net heterotrophic with productivity being negatively influenced by TP, TN, and TOC likely due to a combination of effects including shading by high color dissolved organic matter. We conclude that rainfall patterns, land use, and the resulting discharges of runoff drive the ecology of the C-43/CRE aquatic continuum and associated biogeochemistry rather than water management associated with Lake Okeechobee.

Polychlorinated biphenyls in adult black bass and yellow perch were not associated with their reproductive success in the upper Hudson River, New York, USA.

PubMed

Maceina, Michael J; Sammons, Steven M

2013-07-01

Although production and use of polychlorinated biphenyls (PCBs) ceased nearly 35 yr ago, questions still remain concerning the potential chronic effects these compounds may have on wild fish, including their reproductive success. In the upper Hudson River, New York, USA, fish were exposed to PCBs primarily from 2 manufacturing plants located approximately 320 km upstream of New York City, New York, from the 1940s to 1977. The authors collected yellow perch (Perca flavescens), smallmouth bass (Micropterus dolomieu), and largemouth bass (M. salmoides) using electrofishing, measured PCBs in these adults, and estimated abundance and size of their offspring at age 1 yr (age-1 fish). Fish were collected annually from 2004 to 2009 from 1 control site upstream of the PCB discharge sites and from 2 sites downstream from where PCBs were released. These sites (pools) are separated by a series of dams, locks, and canals. Muscle tissue wet weight PCB and lipid-based PCB concentrations in adults in the 2 PCB exposure pools averaged approximately 1 to 3 µg/g and 100 to 500 µg/g, respectively. Age-1 abundances were not related to adult PCB concentrations but were inversely related to river flow. Size of age-1 fish was slightly greater at the PCB-exposure sites. Levels of PCBs in yellow perch, largemouth bass, and smallmouth bass in the upper Hudson River did not impair or reduce recruitment or reproductive success. Copyright © 2013 SETAC.

Experimental investigation of sound generation by a protuberance in a laminar boundary layer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kobayashi, M.; Asai, M.; Inasawa, A.

2014-08-15

Sound radiation from a two-dimensional protuberance glued on the wall in a laminar boundary layer was investigated experimentally at low Mach numbers. When the protuberance was as high as the boundary-layer thickness, a feedback-loop mechanism set in between protuberance-generated sound and Tollmien-Schlichting (T-S) waves generated by the leading-edge receptivity to the upstream-propagating sound. Although occurrence of a separation bubble immediately upstream of the protuberance played important roles in the evolution of instability waves into vortices interacting with the protuberance, the frequency of tonal vortex sound was determined by the selective amplification of T-S waves in the linear instability stage upstreammore » of the separation bubble and was not affected by the instability of the separation bubble.« less

Vestibular development in marsupials and monotremes

PubMed Central

Ashwell, Ken W S; Shulruf, Boaz

2014-01-01

The young of marsupials and monotremes are all born in an immature state, followed by prolonged nurturing by maternal lactation in either a pouch or nest. Nevertheless, the level of locomotor ability required for newborn marsupials and monotremes to reach the safety of the pouch or nest varies considerably: some are transferred to the pouch or nest in an egg (monotremes); others are transferred passively by gravity (e.g. dasyurid marsupials); some have only a horizontal wriggle to make (e.g. peramelid and didelphid marsupials); and others must climb vertically for a long distance to reach the maternal pouch (e.g. diprotodontid marsupials). In the present study, archived sections of the inner ear and hindbrain held in the Bolk, Hill and Hubrecht collections at the Museum für Naturkunde, Berlin, were used to test the relationship between structural maturity of the vestibular apparatus and the locomotor challenges that face the young of these different mammalian groups. A system for staging different levels of structural maturity of the vestibular apparatus was applied to the embryos, pouch young and hatchlings, and correlated with somatic size as indicated by greatest body length. Dasyurids are born at the most immature state, with the vestibular apparatus at little more than the otocyst stage. Peramelids are born with the vestibular apparatus at a more mature state (fully developed semicircular ducts and a ductus reuniens forming between the cochlear duct and saccule, but no semicircular canals). Diprotodontids and monotremes are born with the vestibular apparatus at the most mature state for the non-eutherians (semicircular canals formed, maculae present, but vestibular nuclei in the brainstem not yet differentiated). Monotremes and marsupials reach the later stages of vestibular apparatus development at mean body lengths that lie within the range of those found for laboratory rodents (mouse and rat) reaching the same vestibular stage. PMID:24298911

A semelparous fish continues upstream migration when exposed to alarm cue, but adjusts movement speed and timing

USGS Publications Warehouse

Luhring, Thomas M; Meckley, Trevor D.; Johnson, Nicholas S.; Siefkes, Michael J.; Hume, John B.; Wagner, C. Michael

2016-01-01

Animals make trade-offs between predation risk and pursuit of opportunities such as foraging and reproduction. Trade-offs between antipredator behaviours and foraging are well suited to manipulation in laboratory and field settings and have generated a vast compendium of knowledge. However, much less is known about how animals manage trade-offs between predation risk and pursuit of reproductive opportunities in the absence of the confounding effects of foraging. In the present study, we investigated how the nonfeeding migratory life stage of sea lamprey, Petromyzon marinus, responds to odour from dead conspecifics (a cue that induces avoidance behaviours in laboratory and field studies). We released groups of PIT-tagged sea lamprey 65 m from the shore of Lake Michigan or 287 m upstream in Carp Lake River and used antennas to detect their movements in the river. As the breeding season progressed, sea lamprey initiated upstream movement earlier and were more likely to enter the river. Sea lamprey that began the night in Lake Michigan entered Carp Lake River at higher rates and accelerated upstream when exposed to high concentrations of alarm cue, consistent with animals attempting to minimize time spent in risky areas. Sea lampreys that began the night in the river delayed upstream movement when exposed to alarm cue, consistent with animals sheltering and gathering information about a source of risk. We attribute this context-specific reaction to alarm cue to differences in perceived vulnerability to predation in sheltered positions in the river versus exposed positions in the lake. Once in the river, the vast majority of sea lamprey moved upstream independent of alarm cue or Julian date. Although life-history-induced time and energy budgets place rigid constraints on the direction of migration, sea lamprey attend to predation risk by modifying movement timing and speed.

Design and performance of a 427-meter-per-second-tip-speed two-stage fan having a 2.40 pressure ratio

NASA Technical Reports Server (NTRS)

Cunnan, W. S.; Stevans, W.; Urasek, D. C.

1978-01-01

The aerodynamic design and the overall and blade-element performances are presented of a 427-meter-per-second-tip-speed two-stage fan designed with axially spaced blade rows to reduce noise transmitted upstream of the fan. At design speed the highest recorded adiabatic efficiency was 0.796 at a pressure of 2.30. Peak efficiency was not established at design speed because of a damper failure which terminated testing prematurely. The overall efficiencies, at 60 and 80 percent of design speed, peaked at approximately 0.83.

Photographic copy of drawing by Modjeski and Masters, Engineers of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photographic copy of drawing by Modjeski and Masters, Engineers of the proposed Huey P. Long Bridge Widening. Original drawing located in the office of Modjeski and Masters, Consulting Engineers at 1055 St. Charles Avenue, New Orleans, LA. 70130. JUNE 30, 2004 DRAWING OF THE PROPOSED HUEY P. LONG BRIDGE WIDENING, U.S. 90, MAIN BRIDGE SUPERSTRUCTURE, SHOWING SEQUENCE OF CONSTRUCTION – 16, STAGE 5 (PLACEMENT OF NEW DECK AND FLOOR SYSTEM) AND STAGE 6. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

Photographic copy of drawing by Modjeski and Masters, Engineers of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photographic copy of drawing by Modjeski and Masters, Engineers of the proposed Huey P. Long Bridge Widening. Original drawing located in the office of Modjeski and Masters, Consulting Engineers at 1055 St. Charles Avenue, New Orleans, LA. 70130. JUNE 30, 2004 DRAWING OF THE PROPOSED HUEY P. LONG BRIDGE WIDENING, U.S. 90, MAIN BRIDGE SUPERSTRUCTURE, SHOWING SEQUENCE OF CONSTRUCTION – 14, STAGE 3 – PHASE 1 AND STAGE 3 – PHASE 2. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

Photographic copy of drawing by Modjeski and Masters, Engineers of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photographic copy of drawing by Modjeski and Masters, Engineers of the proposed Huey P. Long Bridge Widening. Original drawing located in the office of Modjeski and Masters, Consulting Engineers at 1055 St. Charles Avenue, New Orleans, LA. 70130. JUNE 30, 2004 DRAWING OF THE PROPOSED HUEY P. LONG BRIDGE WIDENING, U.S. 90, MAIN BRIDGE SUPERSTRUCTURE, SHOWING SEQUENCE OF CONSTRUCTION – 15, STAGE 4 AND STAGE 5 (DECK AND FLOOR SYSTEM REMOVAL). - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

Two-stage bulk electron heating in the diffusion region of anti-parallel symmetric reconnection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Le, Ari Yitzchak; Egedal, Jan; Daughton, William Scott

2016-10-13

Electron bulk energization in the diffusion region during anti-parallel symmetric reconnection entails two stages. First, the inflowing electrons are adiabatically trapped and energized by an ambipolar parallel electric field. Next, the electrons gain energy from the reconnection electric field as they undergo meandering motion. These collisionless mechanisms have been described previously, and they lead to highly structured electron velocity distributions. Furthermore, a simplified control-volume analysis gives estimates for how the net effective heating scales with the upstream plasma conditions in agreement with fully kinetic simulations and spacecraft observations.

Experimental analysis of the flow in a two stage axial compressor at off-design conditions

NASA Astrophysics Data System (ADS)

Massardo, Aristide; Satta, Antonio

1987-05-01

The experimental analysis of the flow that develops in a two-stage axial flow compressor at off-design conditions is presented. The measurements are performed upstream, between, and downstream of the four blade rows of the compressor. The analysis shows the off-design effects on the local conditions of the flow field. Low-energy flow zones are identified, and the development of annulus-boundary-layer, secondary, and tip-clearance flows is shown. The tip-clearance flows are also present in the stator rows with various outlying conditions (stationary or rotating hub).

Risk Factors for Birth Canal Lacerations in Primiparous Women

PubMed Central

Mikolajczyk, Rafael T.; Zhang, Jun; Troendle, James; Chan, Linda

2013-01-01

Lacerations of the birth canal are common side effects of vaginal birth. They are potentially preventable. Although serious long-term consequences have been identified for severe perineal lacerations, less attention has been paid to lacerations in other locations and how the risk factors vary for different lacerations. We analyzed a dataset including 1009 primiparous women with singleton pregnancies and vaginal deliveries, and we examined risk factors for third- and fourth-degree perineal lacerations and periurethral, vaginal, and labial lacerations using logistic regression analysis. Large fetal size (≥ 3500 g) substantially increased the risk of perineal (odd ratio [OR], 3.8; 95% confidence interval [CI], 1.8 to 7.9) and periurethral (OR, 2.3; 95% CI, 1.0 to 5.0) lacerations but not other types of lacerations. Episiotomy had no impact on perineal lacerations (OR 0.9) but had very strong protective effects for other lacerations (OR 0.1). Prolonged second stage of labor (>120 minutes) increased the risk of perineal and vaginal lacerations but reduced the risk for periurethral lacerations. Instrumental deliveries were significant risk factors for third- and fourth-degree perineal lacerations, with by far the strongest effect for low forceps (OR 25.0 versus <3 for outlet forceps, outlet vacuum, and low vacuum). We concluded that separating different birth canal lacerations is critical in identifying risk factors and potential preventive strategies. PMID:18509884

Risk factors for birth canal lacerations in primiparous women.

PubMed

Mikolajczyk, Rafael T; Zhang, Jun; Troendle, James; Chan, Linda

2008-05-01

Lacerations of the birth canal are common side effects of vaginal birth. They are potentially preventable. Although serious long-term consequences have been identified for severe perineal lacerations, less attention has been paid to lacerations in other locations and how the risk factors vary for different lacerations. We analyzed a dataset including 1009 primiparous women with singleton pregnancies and vaginal deliveries, and we examined risk factors for third- and fourth-degree perineal lacerations and periurethral, vaginal, and labial lacerations using logistic regression analysis. Large fetal size (> or = 3500 g) substantially increased the risk of perineal (odd ratio [OR], 3.8; 95% confidence interval [CI], 1.8 to 7.9) and periurethral (OR, 2.3; 95% CI, 1.0 to 5.0) lacerations but not other types of lacerations. Episiotomy had no impact on perineal lacerations (OR 0.9) but had very strong protective effects for other lacerations (OR 0.1). Prolonged second stage of labor (> 120 minutes) increased the risk of perineal and vaginal lacerations but reduced the risk for periurethral lacerations. Instrumental deliveries were significant risk factors for third- and fourth-degree perineal lacerations, with by far the strongest effect for low forceps (OR 25.0 versus < 3 for outlet forceps, outlet vacuum, and low vacuum). We concluded that separating different birth canal lacerations is critical in identifying risk factors and potential preventive strategies.

C-shaped root canal in a maxillary first molar: a case report.

PubMed

Yilmaz, Z; Tuncel, B; Serper, A; Calt, S

2006-02-01

This case report presents an unusual C-shaped root canal system in a maxillary first molar tooth. Although C-shaped root canals are most frequently seen in the mandibular second molar, they may also appear in maxillary molars. A literature search revealed only a few case reports of C-shaped root canal systems in maxillary molars. The present case describes a C-shaped canal in the buccal root of a maxillary first molar. The endodontic access cavity displayed two canal orifices, one leading to the canal system in the buccal root, the other into the palatal root canal system. In the buccal root, what appeared to be the mesial and distal canals joined to form a single C-shaped canal. --Careful examination of radiographs and the internal anatomy of teeth is essential.-- The location and morphology of root canals should be identified at high magnification under the microscope.

Functional morphology of mouthparts and digestive system during larval development of the cleaner shrimp Lysmata amboinensis (de Man, 1888).

PubMed

Tziouveli, Vasiliki; Bastos Gomes, Giana; Bastos-Gomez, Giana; Bellwood, Orpha

2011-09-01

Mouthpart and alimentary canal development was examined in Lysmata amboinensis larvae using scanning electron microscopy and histology. The gross morphological features of external mouthparts and internal digestive tract structures of larvae at different developmental stages indicate that ingestive and digestive capabilities are well developed from early on. With increasing age of the larvae the mouthpart appendages increased in size, the hepatopancreas in tubular density and the midgut in length. The density of setae and robustness of teeth and spines of individual structures increased. The most pronounced changes from early to late stage larvae involved formation of pores on the paragnaths and labrum, transformation of the mandibular spine-like teeth to molar cusps, development of the filter press in the proventriculus and of infoldings in the previously straight hindgut. The results suggest that early stage L. amboinensis larvae may benefit from soft, perhaps gelatinous prey, whereas later stages are better equipped to handle larger, muscular or more fibrous foods. 2011 Wiley-Liss, Inc.

Shaping ability of NT Engine and McXim rotary nickel-titanium instruments in simulated root canals. Part 1.

PubMed

Thompson, S A; Dummer, P M

1997-07-01

The aim of this study was to determine the shaping ability of NT Engine and McXim nickel-titanium rotary instruments in simulated root canals. In all, 40 canals consisting of four different shapes in terms of angle and position of curvature were prepared by a combination of NT Engine and McXim instruments using the technique recommended by the manufacturer. Part 1 of this two-part report describes the efficacy of the instruments in terms of preparation time, instrument failure, canal blockages, loss of canal length and three-dimensional canal form. Overall, the mean preparation time for all canals was 6.01 min, with canal shape having a significant effect (P < 0.01) on the speed of preparation. One instrument fractured and only four instruments deformed, with most of the failures occurring in canals with curves which began 12 mm from the orifice, that is, in short acute curves. None of the canals became blocked with debris. Following preparation, 20 canals retained their original working length but 19 lost length and one gained in length; there were significant differences (P < 0.05) between the canal shapes in terms of mean loss of distance and in the category of distance change. Apical stops as determined from intracanal impressions were present in 37 of the canals; 16 were judged to be of good quality and 21 of poor quality. The canals were found to be smooth in the apical half of the canal in 33 specimens and in the coronal half of 39 specimens. All canals had good taper characteristics and 35 had good flow characteristics. Under the conditions of this study, NT Engine and McXim instruments prepared canals rapidly, with few deformations, no canal blockages and with minimal change in working length. The three-dimensional form of the canals demonstrated good flow and taper characteristics.

Self-preservation of turbulent wakes

NASA Technical Reports Server (NTRS)

Mehta, Jayesh M.

1989-01-01

The present experiment has ascertained the development of the wake flow behind NASA GA(W)-1 airfoils, showing that, in the far wake, the mean velocity profiles exhibit self-similar behavior irrespective of the upstream boundary layer's character. It is noted, however, that the processes by means of which different wakes reach the asymptotic stage can be very different for different types of wake generators.

Estuarine Larval Development and Upstream Post-Larval Migration of Freshwater Shrimps in Two Tropical Rivers of Puerto Rico

Treesearch

Jonathan P. Benstead; James G. March; Catherine M. Pringle

2000-01-01

Migratory freshwater shrimps represent important links between the headwaters and estuaries of many tropical rivers. These species exhibit amphidromous life cycles in which larvae are released by females in upper reaches of rivers; first stage (i.e., newly hatched) larvae drift passively to coastal environments where they develop and metamorphose into postlarvae...

Expression and Distribution of Arylsulfatase B are Closely Associated with Neuron Death in SOD1 G93A Transgenic Mice.

PubMed

Zhang, Jie; Liang, Huiting; Zhu, Lei; Gan, Weiming; Tang, Chunyan; Li, Jiao; Xu, Renshi

2018-02-01

The known proteins only explained the partial pathogenesis of amyotrophic lateral sclerosis (ALS). Therefore, this study aimed to search the novel proteins possibly involved in ALS. In this study, we analyzed the expression and distribution of the candidate protein arylsulfatase B (ARSB) in the different segments, anatomic regions, and neural cells of spinal cord at the different stages of the wild-type and [Cu/Zn] superoxide dismutase 1 (SOD1) G93A transgenic mice using the fluorescent immunohistochemistry and the western blot. The results revealed that the ARSB was extensively expressed and distributed in the entire spinal cord; the expression and distribution of ARSB was significantly different in the different regions of spinal cord, the anterior horn of gray matter (AHGM) was significantly more than that in the posterior horn of gray matter (PHGM) and significantly more than that in the central canal, and ARSB was mainly distributed in the microglia and neuron cells in the wild-type mice. The expression of ARSB significantly increased in other anatomic regions besides the thoracic PHGM, significantly decreased at the progression stage, occurred in the redistribution from the AHGM and the PHGM to the central canal at the onset and progression stages, and no any alteration of ARSB expression and distribution occurred between the different neural cells in the SOD1 G93A mice compared with the wild-type mice. The increase of ARSB expression and distribution followed with the increased of neuron death. Our data suggested that the abnormal expression and distribution of ARSB were closely associated with the neuron death in the SOD1 G93A transgenic mice.

Endodontic management of maxillary first molar with atypical canal morphology: Report of three cases

PubMed Central

Sherwani, Osama Adeel Khan; Kapoor, Bhumika; Sharma, Rajat; Mishra, Surendra Kumar

2016-01-01

Maxillary first molar with three roots and 3–4 canals is a common occurrence. However, extreme variations in their canal morphology have been reported ranging from one single canal and one root to as many as eight root canals. This article presents three cases of successful endodontic management of maxillary first molars with atypical canal morphologies, thus highlighting the fact that variations do occur and an endodontist should always be aware of aberrancies in root canal system apart from the knowledge of normal root canal anatomy. PMID:27994427

Man-made climatic changes in the Ganges basin

NASA Astrophysics Data System (ADS)

Adel, Miah M.

2002-06-01

Climate data pertaining to the Ganges basin in Bangladesh were analysed to find any climatic changes in the wake of the upstream water diversion by the Farakka Barrage. Whereas the diversions have been continuing from at least 30 international rivers upstream of Bangladesh, the diversion from the Ganges is the best known and has a wider coverage than all other diversions. The diversion reduced the Ganges' discharge through the delta by about 60% from a pre-diversion average value of 1932 m3 s-1, decreased water availability in flood plains, ponds, canals, and ditches by about 50%, dropped the groundwater table, and caused changes in surface features. It took about 5 years of diversions beyond the test run year of 1975 for the environment to react to set 1981 as the baseline year. During the post-baseline era: (1) heating degree days and cooling degree days were respectively 1.33 and 1.44 times more than their counterparts during the pre-baseline era; (2) the summertime and wintertime average temperatures were respectively 1 °C more and 0.5 °C less than the corresponding values during the pre-baseline era; (3) the mode 32 °C of summertime maximum temperatures was 1 °C higher and occurred 414 times more, and the mode 25 °C of wintertime temperature was 1 °C less and occurred 17 times less than the corresponding quantities during the pre-baseline era; (4) the average value of maximum relative humidity has increased by more than 2% and that of minimum relative humidity has dropped by the same amount; (5) the mode 95% and 70% of maximum and minimum relative humidity values have occurred 1322 times and 84 times more respectively than their pre-baseline counterparts; and (6) the frequency for 100 mm or more rainfall and the monthly average rainfalls have dropped by about 50% and 30% respectively. The solution to the climatic changes lies in the restoration of the virgin Ganges flow, dredging of the Ganges and its distributaries to remove shoals and siltation, and re-excavation of canals for water discharge to depleted surface water bodies to re-establish the lost wetland ecosystems. The findings are useful for climate modellers to predict the climatic changes due to changes in surface features, for policy makers of governments of riparian countries constructing dams/barrages on international rivers for unilateral diversion of water, and for donor agencies who finance such projects.

The buccohypophyseal canal is an ancestral vertebrate trait maintained by modulation in sonic hedgehog signaling

PubMed Central

2013-01-01

Background The pituitary gland is formed by the juxtaposition of two tissues: neuroectoderm arising from the basal diencephalon, and oral epithelium, which invaginates towards the central nervous system from the roof of the mouth. The oral invagination that reaches the brain from the mouth is referred to as Rathke’s pouch, with the tip forming the adenohypophysis and the stalk disappearing after the earliest stages of development. In tetrapods, formation of the cranial base establishes a definitive barrier between the pituitary and oral cavity; however, numerous extinct and extant vertebrate species retain an open buccohypophyseal canal in adulthood, a vestige of the stalk of Rathke’s pouch. Little is currently known about the formation and function of this structure. Here we have investigated molecular mechanisms driving the formation of the buccohypophyseal canal and their evolutionary significance. Results We show that Rathke’s pouch is located at a boundary region delineated by endoderm, neural crest-derived oral mesenchyme and the anterior limit of the notochord, using CD1, R26R-Sox17-Cre and R26R-Wnt1-Cre mouse lines. As revealed by synchrotron X-ray microtomography after iodine staining in mouse embryos, the pouch has a lobulated three-dimensional structure that embraces the descending diencephalon during pituitary formation. Polarisfl/fl; Wnt1-Cre, Ofd1-/- and Kif3a-/- primary cilia mouse mutants have abnormal sonic hedgehog (Shh) signaling and all present with malformations of the anterior pituitary gland and midline structures of the anterior cranial base. Changes in the expressions of Shh downstream genes are confirmed in Gas1-/- mice. From an evolutionary perspective, persistence of the buccohypophyseal canal is a basal character for all vertebrates and its maintenance in several groups is related to a specific morphology of the midline that can be related to modulation in Shh signaling. Conclusion These results provide insight into a poorly understood ancestral vertebrate structure. It appears that the opening of the buccohypophyseal canal depends upon Shh signaling and that modulation in this pathway most probably accounts for its persistence in phylogeny. PMID:23537390

Evidence for Recent Activity on the Chatham Strait Fault from Seismic Reflection and GPS Modeling, Southeastern Alaska

NASA Astrophysics Data System (ADS)

Conrad, J. E.; Brothers, D. S.; Elliott, J.; Haeussler, P. J.

2016-12-01

Chatham Strait and its northern extension, Lynn Canal, form the southern end of the Denali fault system, which arcs across southern Alaska and the Yukon Territory. Paleozoic rocks are offset by 180 km across Chatham Strait, confirming a history of significant dextral faulting. Tertiary volcanic rocks on either side of the fault, dated on one side at 28 Ma, have been interpreted as a piercing point indicating post-Oligocene movement. Historical seismic activity is low along the length of Chatham Strait fault (CSF), but the prominent geomorphological expression of the CSF continues to invite the idea that the fault is active and carries some component of modern plate motion, linking to the Eastern Denali fault at the northern end of Lynn Canal. In 2015, the USGS collected high-frequency chirp and multichannel seismic (MCS) reflection profiles in Lynn Canal, in order to image evidence of deformation related to offset along the CSF. During the Last Glacial Maximum, Lynn Canal was completely filled with ice, which mostly removed older sediments and left an irregular but freshly scraped bedrock surface upon deglaciation. MCS profiles image a sequence of younger onlapping sediments that thicken from about 150 m in the north part of the study area to over 250 m in the south. These sediments record the transition from an initial outwash phase with rapid deposition during early stages of deglaciation to deposition in current open-water conditions in depths of 275-325 m that span the last 12,000-14,000 years. Seismic reflection profiles show only minor and localized faulting in these sediments, and there is no evidence of any continuous deformation along the axis of Lynn Canal that would suggest significant offset along the CSF. Fault models constrained by GPS data allow, but do not require, a maximum slip rate of about 2-3 mm/yr along the CSF; higher slip rates on the CSF result in significant misfit to GPS data in the surrounding region. Overall, our results suggest that slip rates may be <1 mm/yr, and it is plausible that the CSF has no current activity.

The buccohypophyseal canal is an ancestral vertebrate trait maintained by modulation in sonic hedgehog signaling.

PubMed

Khonsari, Roman H; Seppala, Maisa; Pradel, Alan; Dutel, Hugo; Clément, Gaël; Lebedev, Oleg; Ghafoor, Sarah; Rothova, Michaela; Tucker, Abigael; Maisey, John G; Fan, Chen-Ming; Kawasaki, Maiko; Ohazama, Atsushi; Tafforeau, Paul; Franco, Brunella; Helms, Jill; Haycraft, Courtney J; David, Albert; Janvier, Philippe; Cobourne, Martyn T; Sharpe, Paul T

2013-03-28

The pituitary gland is formed by the juxtaposition of two tissues: neuroectoderm arising from the basal diencephalon, and oral epithelium, which invaginates towards the central nervous system from the roof of the mouth. The oral invagination that reaches the brain from the mouth is referred to as Rathke's pouch, with the tip forming the adenohypophysis and the stalk disappearing after the earliest stages of development. In tetrapods, formation of the cranial base establishes a definitive barrier between the pituitary and oral cavity; however, numerous extinct and extant vertebrate species retain an open buccohypophyseal canal in adulthood, a vestige of the stalk of Rathke's pouch. Little is currently known about the formation and function of this structure. Here we have investigated molecular mechanisms driving the formation of the buccohypophyseal canal and their evolutionary significance. We show that Rathke's pouch is located at a boundary region delineated by endoderm, neural crest-derived oral mesenchyme and the anterior limit of the notochord, using CD1, R26R-Sox17-Cre and R26R-Wnt1-Cre mouse lines. As revealed by synchrotron X-ray microtomography after iodine staining in mouse embryos, the pouch has a lobulated three-dimensional structure that embraces the descending diencephalon during pituitary formation. Polaris(fl/fl); Wnt1-Cre, Ofd1(-/-) and Kif3a(-/-) primary cilia mouse mutants have abnormal sonic hedgehog (Shh) signaling and all present with malformations of the anterior pituitary gland and midline structures of the anterior cranial base. Changes in the expressions of Shh downstream genes are confirmed in Gas1(-/-) mice. From an evolutionary perspective, persistence of the buccohypophyseal canal is a basal character for all vertebrates and its maintenance in several groups is related to a specific morphology of the midline that can be related to modulation in Shh signaling. These results provide insight into a poorly understood ancestral vertebrate structure. It appears that the opening of the buccohypophyseal canal depends upon Shh signaling and that modulation in this pathway most probably accounts for its persistence in phylogeny.

Surgical treatment of cholesteatoma: a comparison of three techniques.

PubMed

Toner, J G; Smyth, G D

1990-07-01

The debate regarding the surgical technique for the management of cholesteatoma still continues. The resolution of this issue will only come with the study of the long term results of well controlled series. In this paper long term follow-up on three groups of patients is reported. The groups underwent combined approach tympanoplasty (CAT), mastoid tympanoplasty with obliteration (MOT), and modified radical mastoidectomy (MRM) respectively for cholesteatoma. The factors studied included frequency of required review, condition of the external canal/cavity, and hearing status. The meatal cross-sectional areas and cavity volumes were also measured for the MRM and MOT groups. Analysis of the data showed no significant difference between the groups in either frequency of review or cavity status. The hearing results showed an initial improvement in all groups, however, over the prolonged follow-up period the air conduction threshold gradually increased. In conclusion this data supports the view that a one-stage canal wall down procedure provides maximum long term patient benefit.

Canal transportation after root canal instrumentation: a comparative study with computed tomography.

PubMed

Hartmann, Mateus Silveira Martins; Barletta, Fernando Branco; Camargo Fontanella, Vânia Regina; Vanni, José Roberto

2007-08-01

This in vitro study used computed tomography (CT) to compare the occurrence of canal transportation in the apical third of mesiobuccal canals in maxillary molars instrumented with 3 techniques. Sixty teeth were assigned to 3 groups (n = 20), and the root canals were instrumented as follows: Group 1, hand instrumentation with K-files; Group 2, K-files coupled to an oscillatory system powered by an electric engine; Group 3, ProTaper NiTi rotary system powered by an electric engine. To compare the canal transportation produced by the different techniques, preinstrumentation and postinstrumentation 3-dimensional CT images were obtained from root cross-sections of the region located 3 mm short of the apical foramen of each root canal. The CT scans were exported to Adobe Photoshop software, and the initial and final images were superimposed to detect the root canal wall differences between them. Canal transportation was measured by the distance between the prepared canal center and the anatomic canal center. The manual technique produced lesser canal transportation (0.10 mm) than the oscillatory and rotary techniques (0.37 and 0.22 mm, respectively); this difference was statistically significant (P=.021). All studied techniques produced canal transportation.

Upstream migration of Pacific lampreys in the John Day River, Oregon: Behavior, timing, and habitat use

USGS Publications Warehouse

Robinson, T. Craig; Bayer, J.M.

2005-01-01

Adult Pacific lamprey migration and habitat preferences for over-winter holding and spawning, and larval rearing in tributaries to the Columbia River are not well understood. The John Day River is one such tributary where larval and adult stages of this species have been documented, and its free-flowing character provided the opportunity to study migration of Pacific lampreys unimpeded by passage constraints. Forty-two adult Pacific lampreys were captured in the John Day River near its mouth during their upstream migration. Pacific lampreys were surgically implanted with radio transmitters and released onsite, and tracked by fixed-site, aerial, and terrestrial telemetry methods for nearly one year. Adults moved upstream exclusively at night, with a mean rate of 11.1 ?? 6.3 km/day. They halted upstream migration by September, and held a single position for approximately six months in the lateral margins of riffles and glides, using boulders for cover. More than half of Pacific lampreys resumed migration in March before ending movement in early May. Pacific lampreys that resumed migration in spring completed a median of 87% of their upstream migration before over-winter holding. Upon completing migration. Pacific lampreys briefly held position before beginning downstream movement at the end of May. Though not directly observed, halting migration and movement downstream were likely the result of spawning and death. Gains in adult Pacific lamprey passage through the Columbia River hydrosystem and tributaries may be made by improvements that would expedite migration during spring and summer and increase the quantity and variety of cover and refuge opportunities. ?? 2005 by the Northwest Scientific Association. All rights reserved.

The giant mottled eel, Anguilla marmorata, uses blue-shifted rod photoreceptors during upstream migration.

PubMed

Wang, Feng-Yu; Fu, Wen-Chun; Wang, I-Li; Yan, Hong Young; Wang, Tzi-Yuan

2014-01-01

Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. Anguilla marmorata, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity and opsin gene expression of A. marmorata during upstream migration. Microspectrophotometry analysis revealed that the tropical eel possesses a duplex retina with rod and cone photoreceptors. The λmax of rod cells are 493, 489, and 489 nm in glass, yellow, and wild eels, while those of cone cells are 508, and 517 nm in yellow, and wild eels, respectively. Unlike European and American eels, Asian eels exhibited a blue-shifted pattern of rod photoreceptors during upstream migration. Quantitative gene expression analyses of four cloned opsin genes (Rh1f, Rh1d, Rh2, and SWS2) revealed that Rh1f expression is dominant at all three stages, while Rh1d is expressed only in older yellow eel. Furthermore, sequence comparison and protein modeling studies implied that a blue shift in Rh1d opsin may be induced by two known (N83, S292) and four putative (S124, V189, V286, I290) tuning sites adjacent to the retinal binding sites. Finally, expression of blue-shifted Rh1d opsin resulted in a spectral shift in rod photoreceptors. Our observations indicate that the giant mottled eel is color-blind, and its blue-shifted scotopic vision may influence its upstream migration behavior and habitat choice.

160. Photocopy of drawing (taken from Twin Falls Canal Company ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

160. Photocopy of drawing (taken from Twin Falls Canal Company Field Book #361 #86, page 1). SCALE DRAWING, CANAL HEADGATES AND CANAL SURVEY, 'A' LINE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

14. MAIN CANAL CANAL CHECKGATES, JUST BELOW DARK CANYON ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. MAIN CANAL - CANAL CHECKGATES, JUST BELOW DARK CANYON SIPHON, VIEW TO NORTHEAST - Carlsbad Irrigation District, Main Canal, 4 miles North to 12 miles Southeast of Carlsbad, Carlsbad, Eddy County, NM

Limitations of navigation through Nubaria canal, Egypt.

PubMed

Samuel, Magdy G

2014-03-01

Alexandria port is the main Egyptian port at the Mediterranean Sea. It is connected to the Nile River through Nubaria canal, which is a main irrigation canal. The canal was designed to irrigate eight hundred thousand acres of agricultural lands, along its course which extends 100 km. The canal has three barrages and four locks to control the flow and allow light navigation by some small barges. Recently, it was decided to improve the locks located on the canal. More than 40 million US$ was invested in these projects. This decision was taken to allow larger barges and increase the transported capacity through the canal. On the other hand, navigation through canals and restricted shallow waterways is affected by several parameters related to both the channel and the vessel. Navigation lane width as well as vessel speed and maneuverability are affected by both the channel and vessel dimensions. Moreover, vessel dimensions and speed will affect the canal stability. In Egypt, there are no guide rules for navigation through narrow and shallow canals such Nubaria. This situation threatens the canal stability and safety of navigation through it. This paper discussed the characteristics of Nubaria canal and the guide rules for navigation in shallow restricted water ways. Dimensions limitation for barges navigating through Nubaria canal is presented. New safe operation rules for navigation in Nubaria canal are also presented. Moreover, the implication of navigation through locks on canal discharge is estimated.

7. View north at back (canal side) of culvert inlet, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. View north at back (canal side) of culvert inlet, with canal bank completely removed. Background to foreground: back of inlet headwall with tops of high inlet barrels exposed; vertical transition wall between high inlet barrels and low, interior, inlet barrels; tops of low interior barrels; vertical heartening planks and low cutoff wall at site of former canal edge of canal bank; dewatered canal bed and plank sheathing on top of culvert barrels beneath canal bed. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ

Detection of Mesiobuccal Canal in Maxillary Molars and Distolingual Canal in Mandibular Molars by Dental CT: A Retrospective Study of 100 Cases

PubMed Central

Rathi, Sushma; Patil, Jayaprakash; Jaju, Prashant P.

2010-01-01

Objective. To detect presence of MB2 canal in maxillary molars and distolingual canal in mandibular molars by Dental CT. Material and Methods. A retrospective study of 100 Dental CTs was done. Axial and paraxial images obtained were used to assess the presence of MB2 canal in maxillary molars and distolingual canal in mandibular molars. Results. The youngest patient was of 11 years while the eldest patient was of 77 years. Males were 58 in number and females were 42 in number. MB2 canals were present in 57 patients and distolingual canal was present in 18 patients. Maximum MB2 canals were present in age group between 51 and 60 years, while distolingual canals were present in age group of 21–30 years. Conclusion. Dental CT allows adequate visualization of variation in root canal morphology and can be important diagnostic tool for successful endodontic therapy. PMID:20613946

Comparison of canal transportation in simulated curved canals prepared with ProTaper Universal and ProTaper Gold systems

PubMed Central

Muniz, Brenda Leite; Pires, Frederico; Belladonna, Felipe Gonçalves; Neves, Aline Almeida; Souza, Erick Miranda; De-Deus, Gustavo

2016-01-01

Objectives The purpose of this study was to assess the ability of ProTaper Gold (PTG, Dentsply Maillefer) in maintaining the original profile of root canal anatomy. For that, ProTaper Universal (PTU, Dentsply Maillefer) was used as reference techniques for comparison. Materials and Methods Twenty simulated curved canals manufactured in clear resin blocks were randomly assigned to 2 groups (n = 10) according to the system used for canal instrumentation: PTU and PTG groups, upto F2 files (25/0.08). Color stereomicroscopic images from each block were taken exactly at the same position before and after instrumentation. All image processing and data analysis were performed with an open source program (FIJI). Evaluation of canal transportation was obtained for two independent canal regions: straight and curved levels. Student's t test was used with a cut-off for significance set at α = 5%. Results Instrumentation systems significantly influenced canal transportation (p < 0.0001). A significant interaction between instrumentation system and root canal level (p < 0.0001) was found. PTU and PTG systems produced similar canal transportation at the straight part, while PTG system resulted in lower canal transportation than PTU system at the curved part. Canal transportation was higher at the curved canal portion (p < 0.0001). Conclusions PTG system produced overall less canal transportation in the curved portion when compared to PTU system. PMID:26877984

ProTaper rotary instrument fracture during root canal preparation: a comparison between rotary and hybrid techniques.

PubMed

Farid, Huma; Khan, Farhan Raza; Rahman, Munawar

2013-03-01

This study aimed to compare the frequency of ProTaper rotary instrument fracture with rotary (conventional) and hybrid (rotary and hand files) canal preparation techniques. Secondary objectives were to determine whether there was an association of ProTaper file fracture with the canal curvature and to compare the mean time required for canal preparation in the two techniques. An in vitro experiment was conducted on 216 buccal canals of extracted maxillary and mandibular first molars. After creating an access cavity and a glide path for each canal, a periapical radiograph was taken and the canal curvature was measured with Schneider's technique. The canals were then randomly divided into Group A (rotary technique) and Group B (hybrid technique). The length of ProTaper files were measured before and after each canal preparation. Time taken for each canal preparation was recorded. A total of seven ProTaper files fractured in Group A (P=0.014) in canals with a curvature >25 degrees (P<0.001). The mean time taken for preparation of the root canals was 104.04 sec (± 55.7 sec) in Group A versus 122.88 sec (± 41.67 sec) in Group B (P=0.007). In the teeth studied, the hybrid technique of root canal preparation with ProTaper rotary files, although time consuming, was safer in canals having a curvature greater than 25 degrees.

179. Photocopy of Photograph, Twin Falls Canal Company, Bisbee Photo, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

179. Photocopy of Photograph, Twin Falls Canal Company, Bisbee Photo, September, 1912. Photographer unknown. VIEW OF LOW LINE CANAL, TWIN FALLS COUNTY; VIEW OF LOW LINE CANAL IN PETE LINK'S FIELD. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

[Rehabilitation and algodystrophies].

PubMed

Simon, L; Blotman, F; Leroux, J L; Claustre, J; Azema, M J; Brun-Meyer, M

1982-12-01

Based on 20 years experience, and a personal series of 272 cases of reflex dystrophy (84 cases involving upper limbs, 188 cases involving lower limbs) admitted under a rheumatology unit equipped with all the available techniques of rehabilitative medicine, the authors stress the value of well conducted functional rehabilitation which, even alone, can obtain excellent results in the treatment of this disease, whatever the stage. The authors detail the modalities of this treatment. A local intra-articular or intra-canal injection of corticosteroids permits pain-free physiotherapy. The mobilisation of the lower limb is an urgent priority. Non-aggressive physiotherapeutic techniques should be adapted to the stage and the site of reflex dystrophy. Hydrokinesitherapy and the adaptation of craft techniques to occupational therapy also play an important part.

Micro-CT analyses of apical enlargement and molar root canal complexity.

PubMed

Markvart, M; Darvann, T A; Larsen, P; Dalstra, M; Kreiborg, S; Bjørndal, L

2012-03-01

To compare the effectiveness of two rotary hybrid instrumentation techniques with focus on apical enlargement in molar teeth and to quantify and visualize spatial details of instrumentation efficacy in root canals of different complexity. Maxillary and mandibular molar teeth were scanned using X-ray microcomputed tomography. Root canals were prepared using either a GT/Profile protocol or a RaCe/NiTi protocol. Variables used for evaluation were the following: distance between root canal surfaces before and after preparation (distance after preparation, DAP), percentage of root canal area remaining unprepared and increase in canal volume after preparation. Root canals were classified according to size and complexity, and consequences of unprepared portions of narrow root canals and intraradicular connections/isthmuses were included in the analyses. One- and two-way anova were used in the statistical analyses. No difference was found between the two techniques: DAP(apical-third) (P = 0.590), area unprepared(apical-third) (P = 0.126) and volume increase(apical-third) (P = 0.821). Unprepared root canal area became larger in relation to root canal size and complexity, irrespective of the technique used. Percentage of root canal area remaining unprepared was significantly lower in small root canals and complex systems compared to large root canals. The isthmus area per se contributed with a mean of 17.6%, and with a mean of 25.7%, when a narrow root canal remained unprepared. The addition of isthmuses did not significantly alter the ratio of instrumented to unprepared areas at total root canal level. Distal and palatal root canals had the highest level of unprepared area irrespective of the two instrumentation techniques examined. © 2011 International Endodontic Journal.

A cone-beam computed tomography study of maxillary first permanent molar root and canal morphology in a Chinese population.

PubMed

Zheng, Qing-hua; Wang, Yao; Zhou, Xue-dong; Wang, Qian; Zheng, Guang-ning; Huang, Ding-ming

2010-09-01

This study evaluated root and canal morphology of permanent maxillary first molars in a Chinese population using cone-beam computed tomography scanning. The sample included 775 cone-beam computed tomography images of maxillary first molars; 627 of the subjects had unilateral qualifying molars and 74 had bilateral qualifying molars. The following observations were made: (1) frequency of root and canal numbers, (2) frequency of additional canals in the mesiobuccal root by sex, age, and tooth position, and (3) unilateral and bilateral occurrence of additional canals in the mesiobuccal root. Fused roots were present in 2.71% of unilateral qualifying molars. Multiple canals were present in the following frequencies: two canals in 0.31%, three canals in 47.21%, four canals in 50.40%, five canals in 1.75%, and six canals in 0.31% of teeth. Additional canals were detected in 52.24% of mesiobuccal roots, 1.12% of distobuccal roots, and 1.76% of palatal roots. Patients aged 20 to 30 years showed a higher prevalence of additional mesiobuccal root canals. This prevalence did not differ with sex and tooth position. Most (71.11%) of the additional mesiobuccal root canals in subjects with bilateral qualifying molars were symmetric. Cone-beam computed tomography scanning is an effective method for studying external and internal dental morphology. The root and canal configurations of maxillary first molars in this Chinese population were consistent with previously reported data. More attention should be given to the detection of additional canals in patients between 20 and 30 years of age. These data may facilitate successful endodontic treatment. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Evaluation of Root Canal Configuration of Mandibular First Molars in a Palestinian Population by Using Cone-Beam Computed Tomography: An Ex Vivo Study

PubMed Central

Mukhaimer, Raed Hakam

2014-01-01

Aim. The purpose of this study was to investigate the number of canals and variations in root canal configuration in the mandibular permanent first molar teeth of a Palestinian population using cone-beam computed tomography (CBCT). Methods. A sample of 320 extracted double-rooted mandibular permanent first molars from Palestinian population was collected for this study and scanned with CBCT scanner. The following observations were made: number of root canals per root and canal configuration in each root based on Vertucci's classification. Results. Of the 320 mandibular first molars analyzed, 174 (54.4%) had three canals, 132 teeth (41.3%) had four canals, and only four teeth had two canals. The most common canal configuration in the mesial roots was Vertucci type IV (53.8%) followed by type II (38.8%). In the distal roots, the most prevalent canal configuration was Vertucci type I (57.5%) followed by type II ( 22.5%) and type III (10.6%). Conclusion. Our results showed that the number of canals and canal configuration in Palestinian population were consistent with previously reported data. The present study also indicates that CBCT is helpful as a diagnostic tool for the investigation of root canal morphology. PMID:27379321

8. BLACK RIVER CANAL LOOKING DOWN CANAL WITH LATERAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. BLACK RIVER CANAL - LOOKING DOWN CANAL WITH LATERAL TURNOUT NO. 1 ON THE RIGHT. VIEW TO THE SOUTHEAST - Carlsbad Irrigation District, Black River Canal, 15 miles Southeast of Carlsbad near Malaga, Carlsbad, Eddy County, NM

[Root canal treatment of mandibular first premolar with 4 root canals: a case report].

PubMed

Liu, Xin-yang; Zhan, Fu-Liang

2015-10-01

The mandibular first premolar can be considered one of the most challenging teeth to treat, due to the complexity of its root canal morphology and increased incidence of multiple canals. A case of endodontic treatment of a mandibular first premolar exhibiting a total of 4 distinct root canals and 4 apical foramina was described. Anatomic variation of root canal morphology should be considered in endodontic treatment to ensure a favorable healing outcome, and its identification could be enhanced by careful examination using a dental operating microscope. Obturation of root canals using a warm vertical compaction technique with a highly-radiopaque root canal sealer, such as AH Plus, after careful ultrasonic activated irrigation might allow the flow of sealer into the narrowed but unprepared part of the canal, thereby facilitating optimum chemo-mechanical debridement of the root canal system.

A simplified technique of orthograde MTA obturation on the elected canals of posterior teeth: Two case reports.

PubMed

Wahengbam, Brucelee; Wahengbam, Pragya; Tikku, Aseem Prakash

2014-01-01

This article suggests a simplified technique of orthograde MTA obturation in less accessible canal(s) of posteriors teeth without using costly ultrasonics or specialised carrier. Essentially few finger pluggers, absorbent points and a simple canal projection method were used. The orifice(s) of the elected canal(s) to be obturated with MTA were projected onto the external occlusal surface for easy delivery and predictive instrumentation. The idea was based on 'easy access', 'working one canal with one mix at one time', 'thorough condensation' and 'removal of excess moisture'. In case I, palatal canal of tooth no. 2 with gross apical perforation and suspected VRF was obturated with MTA. And in Case II, tooth no. 19 presented with incomplete furcal fracture extending into the canal was obturated with MTA in all 3 canals unitarily. Dense homogenous MTA obturation was achieved and both cases healed uneventfully.

Endodontic management of middle mesial canal of the mandibular molar

PubMed Central

Sundaresh, K J; Srinivasan, Raghu; Mallikarjuna, Rachappa; Rajalbandi, Sandeep

2013-01-01

Thorough knowledge of root canal morphology and unusual anatomy of the tooth is critical for successful endodontic treatment. Although the most common configuration is two roots and three root canals, mandibular molars might have many different combinations. In the literature, it is less described about three mesial canals and two distal canals in mandibular second molars, indicating a rare anatomical configuration. A case of unusual root canal morphology is presented to demonstrate anatomical variations in mandibular molars. Endodontic therapy was performed in a mandibular second molar with five separate canals, three mesial and two distal. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure. In conclusion, every attempt should be made to find and treat all root canals of a tooth. PMID:23349182

Flood-inundation maps for the West Branch Susquehanna River near the Boroughs of Lewisburg and Milton, Pennsylvania

USGS Publications Warehouse

Roland, Mark A.; Hoffman, Scott A.

2014-01-01

Digital flood-inundation maps for an approximate 8-mile reach of the West Branch Susquehanna River from approximately 2 miles downstream from the Borough of Lewisburg, extending upstream to approximately 1 mile upstream from the Borough of Milton, Pennsylvania, were created by the U.S. Geological Survey (USGS) in cooperation with the Susquehanna River Basin Commission (SRBC). The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict the estimated areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage 01553500, West Branch Susquehanna River at Lewisburg, Pa. In addition, the information has been provided to the Susquehanna River Basin Commission (SRBC) for incorporation into their Susquehanna Inundation Map Viewer (SIMV) flood warning system (http://maps.srbc.net/simv/). The National Weather Service (NWS) forecasted peak-stage information (http://water.weather.gov/ahps) for USGS streamgage 01553500, West Branch Susquehanna River at Lewisburg, Pa., may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. Calibration of the model was achieved using the most current stage-discharge relations (rating number 11.1) at USGS streamgage 01553500, West Branch Susquehanna River at Lewisburg, Pa., a documented water-surface profile from the December 2, 2010, flood, and recorded peak stage data. The hydraulic model was then used to determine 26 water-surface profiles for flood stages at 1-foot intervals referenced to the streamgage datum ranging from 14 feet (ft) to 39 ft. Modeled flood stages, as defined by NWS, include Action Stage, 14 ft; Flood Stage, 18 ft; Moderate Flood Stage, 23 ft; and Major Flood Stage, 28 ft. Geographic information system (GIS) technology was then used to combine the simulated water-surface profiles with a digital elevation model (DEM) derived from light detection and ranging (lidar) data to delineate the area flooded at each water level. The availability of these maps, along with World Wide Web information regarding current stage from USGS streamgages and forecasted stream stages from the NWS, provide emergency management personnel and residents with information that is critical for flood response activities, such as evacuations and road closures, as well as for post-flood recovery efforts.

TANDEM: a two-stage approach to maximize interpretability of drug response models based on multiple molecular data types.

PubMed

Aben, Nanne; Vis, Daniel J; Michaut, Magali; Wessels, Lodewyk F A

2016-09-01

Clinical response to anti-cancer drugs varies between patients. A large portion of this variation can be explained by differences in molecular features, such as mutation status, copy number alterations, methylation and gene expression profiles. We show that the classic approach for combining these molecular features (Elastic Net regression on all molecular features simultaneously) results in models that are almost exclusively based on gene expression. The gene expression features selected by the classic approach are difficult to interpret as they often represent poorly studied combinations of genes, activated by aberrations in upstream signaling pathways. To utilize all data types in a more balanced way, we developed TANDEM, a two-stage approach in which the first stage explains response using upstream features (mutations, copy number, methylation and cancer type) and the second stage explains the remainder using downstream features (gene expression). Applying TANDEM to 934 cell lines profiled across 265 drugs (GDSC1000), we show that the resulting models are more interpretable, while retaining the same predictive performance as the classic approach. Using the more balanced contributions per data type as determined with TANDEM, we find that response to MAPK pathway inhibitors is largely predicted by mutation data, while predicting response to DNA damaging agents requires gene expression data, in particular SLFN11 expression. TANDEM is available as an R package on CRAN (for more information, see http://ccb.nki.nl/software/tandem). m.michaut@nki.nl or l.wessels@nki.nl Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Single-rooted maxillary first molar with a single canal: endodontic retreatment.

PubMed

de la Torre, Francisco; Cisneros-Cabello, Rafael; Aranguren, José Luis; Estévez, Roberto; Velasco-Ortega, Eugenio; Segura-Egea, Juan José

2008-12-01

This case report presents an unusual root canal system in a maxillary first molar tooth: a single canal in a single root. The endodontic access cavity displayed only 1 canal orifice. This case demonstrated that: 1) clinicians must have adequate knowledge about root canal morphology and its variations; 2) the location and morphology of root canals should be identified radiologically before the root canal treatment; and 3) careful examination of radiographs and the internal anatomy of teeth is essential.

Response of the Rio Grande and shallow ground water in the Mesilla Bolson to irrigation, climate stress, and pumping

USGS Publications Warehouse

Walton, J.; Ohlmacher, G.; Utz, D.; Kutianawala, M.

1999-01-01

The El Paso-Ciudad Juarez metropolitan area obtains its water from the Rio Grande and intermontane-basin aquifers. Shallow ground water in this region is in close communications with the surface water system. A major problem with both systems is salinity. Upstream usage of the water in the Rio Grande for irrigation and municipalities has led to concentration of soluble salts to the point where the surface water commonly exceeds drinking water standards. Shallow ground water is recharged by surface water (primarily irrigation canals and agricultural fields) and discharges to surface water (agricultural drains) and deeper ground water. The source of water entering the Rio Grande varies seasonally. During the irrigation season, water is released from reservoirs and mixes with the return flow from irrigation drains. During the non-irrigation season (winter), flow is from irrigation drains and river water quality is indicative of shallow ground water. The annual cycle can be ascertained from the inverse correlation between ion concentrations and discharge in the river. Water-quality data indicate that the salinity of shallow ground water increases each year during a drought. Water-management strategies in the region can affect water quality. Increasing the pumping rate of water-supply wells will cause shallow ground water to flow into the deeper aquifers and degrade the water quality. Lining the canals in the irrigation system to stop water leakage will lead to water quality degradation in shallow ground water and, eventually, deep ground water by removing a major source of high quality recharge that currently lowers the salinity of the shallow ground water.

[Continuous observation of canal aberrations in S-shaped simulated root canal prepared by hand-used ProTaper files].

PubMed

Xia, Ling-yun; Leng, Wei-dong; Mao, Min; Yang, Guo-biao; Xiang, Yong-gang; Chen, Xin-mei

2009-08-01

To observe the formation of canal aberrations in S-shaped root canals prepared by every file of hand-used ProTaper. Fifteen S-shaped simulated resin root canals were selected. Each root canal was prepared by every file of hand-used ProTaper following the manufacturer instruction. The images of canals prepared by S1, S2, F1, F2 and F3 were taken and stored, which were divided into group S1, S2, F1, F2 and F3. One image of canal unprepared was superposed with the images of the same root canal in these five groups respectively to observe the types and number of canal aberrations, which included unprepared area, danger zone, ledge, elbow, zip and perforation. SPSS12.0 software pakage was used for Fisher's exact probabilities in 2x2 table. Unprepared area decreased following preparation by every file of ProTaper, but it still existed when the canal preparation was finished. The incidence of danger zone, elbow and zip in group F1 was 15/15, 11/15, 4/15, respectively, which was significantly higher than that in group S2(2/15,0,0) (P<0.001). Ledge appeared after prepared by F2, and increased sharply in group F3. None perforation was found in all groups. The incidence of canal aberrations begins to increase after prepared by finishing files of ProTaper.The presence of unprepared area suggests that it is essential to rinse canal abundantly during complicated canal preparation and canal antisepsis after preparation.

9. BLACK RIVER CANAL CANAL (RIGHT), DISCHARGE GATE (BACKGROUND), ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. BLACK RIVER CANAL - CANAL (RIGHT), DISCHARGE GATE (BACKGROUND), FARMER'S TURNOUT (LEFT), AND LATERAL NO. 14 (FOREGROUND). VIEW TO SOUTHEAST - Carlsbad Irrigation District, Black River Canal, 15 miles Southeast of Carlsbad near Malaga, Carlsbad, Eddy County, NM

Cleaning and shaping curved root canals: Mtwo vs ProTaper instruments, a lab comparison.

PubMed

Kuzekanani, Maryam; Walsh, Laurence J; Yousefi, Mohammad Ali

2009-01-01

The purpose of this study was to compare root canal preparation in curved canals in molar teeth with the rotary NiTi Mtwo and ProTaper systems in terms of canal shape and smear layer. Mesiobuccal canals of 60 molar teeth with angles of curvature between 25 and 35 degrees were prepared with a torque controlled low speed engine; 30 canals for each system. Each individual instrument was used to prepare four root canals and the time required for preparation was recorded. Standardized radiographs were taken before and following instrumentation and used to determine changes in canal curvature. There was no significant difference in preparation time between the two systems. No instruments separated during use. The Mtwo system gave a statistically smaller change in canal curvature and thus was better for maintaining the original shape of the root canal, with less transportation (P less than 0.05). The greatest difference was seen for maxillary molar teeth. When prepared root canals were examined by SEM there was no difference between the two systems at the coronal, middle or apical thirds. Overall, the results of this study suggest that Mtwo instruments are preferable for situations where canals are curved, particularly for maxillary molars.

Shaping ability of ProFile.04 Taper Series 29 rotary nickel-titanium instruments in simulated root canals. Part 1.

PubMed

Thompson, S A; Dummer, P M

1997-01-01

The aim of this study was to determine the shaping ability of ProFile.04 Taper Series 29 nickel-titanium instruments in simulated canals. A total of 40 simulated root canals made up of four different shapes in terms of angle and position of curvature were prepared by ProFile instruments using a step-down approach. Part 1 of this two-part report describes the efficacy of the instruments in terms of preparation time, instrument failure, canal blockages, loss of canal length and three-dimensional canal form. The time necessary for canal preparation was not influenced significantly by canal shape. No instrument fractures occurred but a total of 52 instruments deformed. Size 6 instruments deformed the most followed by sizes 5, 3 and 4. Canal shape did not influence significantly instrument deformation. None of the canals became blocked with debris and loss of working distance was on average 0.5 mm or less. Intracanal impressions of canal form demonstrated that most canals had definite apical stops, smooth canal walls and good flow and taper. Under the conditions of this study, ProFile.04 Taper Series 29 rotary nickel-titanium instruments prepared simulated canals rapidly and created good three-dimensional form. A substantial number of instruments deformed but it was not possible to determine whether this phenomenon occurred because of the nature of the experimental model or through an inherent design weakness in the instruments.

Infrastructure performance of irrigation canal to irrigation efficiency of irrigation area of Candi Limo in Mojokerto District

NASA Astrophysics Data System (ADS)

Kisnanto, S.; Hadiani, R. R. R.; Ikhsan, C.

2018-03-01

Performance is a measure of infrastructure success in delivering the benefits corresponding it’s design implementation. Debit efficiency is a comparison between outflow debit and inflow debit. Irrigation canal performance is part of the overall performance aspects of an irrigation area. The greater of the canal performance will be concluded that the canal is increasingly able to meet the planned benefits, need to be seen its comparison between the performance and debit efficiency of the canal. The existing problems in the field that the value of the performance of irrigation canals are not always comparable to the debit efficiency. This study was conducted to describe the relationship between the performance of the canal to the canal debit efficiency. The study was conducted at Candi Limo Irrigation Area in Mojokerto Disctrict under the authority of Pemerintahan Provinsi Jawa Timur. The primary canal and secondary canal are surveyed to obtain data. The physical condition of the primary and secondary canals into the material of this study also. Primary and secondary canal performance based on the physical condition in the field. Measurement inflow and outflow debit into the data for the calculation of the debit efficiency. The instrument used in this study such as the current meter for debit measurements in the field as a solution when there is a building measure in the field were damaged, also using the meter and the camera. Permen PU No.32 is used to determine the value of the performance of the canal, while the efficiency analysis to calculate a comparison value between outflow and inflow debit. The process of data running processing by performing the measurement and calculation of the performance of the canal, the canal debit efficiency value calculation, and display a graph of the relationship between the value of the performance with the debit efficiency in each canal. The expected results of this study that the performance value on the primary canal in the range of 0 to 100 % with debit efficiency value in the range of 0 to 100 %, while for the secondary canal 1 has a performance range between 0 to 100% with efficiency ranges between 0 to 100%, the performance of the secondary canals 2 ranges between 0 to 100% with efficiencies ranging from 0 to 100%, the secondary canal 3 performance ranges between 0 to 100% efficiency ranges between 0 to 100%, the secondary canal 4 performance ranges between 0 to 100% efficiency ranges between 0 to 100% and secondary canals 5 performance ranges between 0 to 100% efficiency ranges between 0 to 100%. For the tendency to expect from the performance and efficiency of the debit canal can have a proportional clockwise or counterclockwise, which amount can be random. The tendency to be graphed the relationship between performance and efficiency of the debit of each segment studied canal.

Panama Canal : a new course for the canal

DOT National Transportation Integrated Search

1999-01-01

While the Panama Canal provides significant time savings, passage through this narrow waterway presents a host of challenges. Soon all canal pilots will have a new tool in their efforts to safely guide vessels through this difficult canal: a Communic...

7. O'BRIAN CANAL After its bifurcation with the DenverHudson Canal, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. O'BRIAN CANAL After its bifurcation with the Denver-Hudson Canal, flowing into Barr Lake through a protected eagle nesting area - O'Brian Canal, South Platte River Drainage Area Northest of Denver, Brighton, Adams County, CO

Materiel Testing in the Tropics (6th Ed)

DTIC Science & Technology

1979-04-01

ceramics Test methodology Panama Canal Zone Textiles Plastics Tropic Test Center Protective coatings Tropical animals 20. (cont) of Materiel Testing in...Canal Zone . .. 1-3 D Materiel Testing in the Panama Canal Zone . . . . . . . ... . 1-5 E Canal Zone Environment--Brief Overview .. .. .... ...... 1-6...trapped there, and by the heavy biomass of the canopy itself. E. CANAL ZONE ENVIRONMENT--BRIEF OVERVIEW The Canal Zone (see frontispiece) bisects the

28. VIEW FROM IMMEDIATELY DOWNSTREAM OF TWIN FALLS MAIN CANAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

28. VIEW FROM IMMEDIATELY DOWNSTREAM OF TWIN FALLS MAIN CANAL HEADWORKS WITH CANAL BRIDGE IN DISTANCE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paller, M.; Blas, S.

The upper portion of Lower Three Runs includes several ponds, reservoirs, and canals that were formerly used as a cooling system for nuclear production reactors. This area was divided into nine exposure areas (EAs) for the assessment of environmental contamination resulting from past reactor operations and other industrial processes. A tiered screening process identified several contaminants of potential concern including aluminum, cyanide, lead, manganese, mercury, DDD, DDE, and DDT. Risks posed by these contaminants to ecological receptors (river otter, belted kingfisher, raccoon, and blue heron) were assessed using contaminant exposure models that estimated contaminant intake resulting from ingestion of food,more » water, and sediment/ soil and compared these intakes with toxicity reference values (TRVs). The contaminant exposure models showed that the TRVs were not exceeded in the otter model, exceeded by aluminum in EA 7 (Pond 2 and associated canals) in the raccoon model, and exceeded by mercury in EAs 2, 3 (Pond B), 6 (Par Pond), and 8 (Ponds 4 and 5 and Canal to Pond C) in both the kingfisher and blue heron models. Hazard quotients (total exposure dose divided by the TRV) were 2.8 for aluminum and 1.7- 3.6 for mercury. The primary route of exposure for aluminum was the ingestion of soil, and the primary route of exposure for mercury was the ingestion of mercury contaminated fish. Elevated levels of mercury in fish were at least partly the result of the aerial deposition of mercury onto Lower Three Runs and its watershed. The atmospheric deposition of mercury creates pervasive contamination in fish throughout the Savannah River basin. Another possible source of mercury was the discharge of mercury contaminated Savannah River water into the Lower Three Runs cooling ponds and canals during previous years of reactor operation. This contamination originated from industries located upstream of the SRS. The aluminum exceedance for the raccoon was likely the result of naturally high aluminum levels in SRS soils rather than SRS operations. Aluminum exceedances have previously been observed in relatively undisturbed background locations as well as areas affected by SRS operations. Aluminum exceedances are more likely with the raccoon than the other receptors because it consumes more soil as a result of its feeding habits. Sensitivity analysis showed that model uncertainty can be reduced by adequate sampling of key variables (e.g., fish and sediments). Although sediment samples were collected from all EAs, fish samples were not collected from three EAs and some analytes (pesticides and cyanide) were not measured in fish. Water-to-fish concentration ratios were used to estimate contaminant levels in fish when direct measurements from fish were unavailable; however, such estimates are potentially less accurate than direct measurements.« less

FAT1 cadherin acts upstream of Hippo signalling through TAZ to regulate neuronal differentiation.

PubMed

Ahmed, Abdulrzag F; de Bock, Charles E; Lincz, Lisa F; Pundavela, Jay; Zouikr, Ihssane; Sontag, Estelle; Hondermarck, Hubert; Thorne, Rick F

2015-12-01

The Hippo pathway is emerging as a critical nexus that balances self-renewal of progenitors against differentiation; however, upstream elements in vertebrate Hippo signalling are poorly understood. High expression of Fat1 cadherin within the developing neuroepithelium and the manifestation of severe neurological phenotypes in Fat1-knockout mice suggest roles in neurogenesis. Using the SH-SY5Y model of neuronal differentiation and employing gene silencing techniques, we show that FAT1 acts to control neurite outgrowth, also driving cells towards terminal differentiation via inhibitory effects on proliferation. FAT1 actions were shown to be mediated through Hippo signalling where it activated core Hippo kinase components and antagonised functions of the Hippo effector TAZ. Suppression of FAT1 promoted the nucleocytoplasmic shuttling of TAZ leading to enhanced transcription of the Hippo target gene CTGF together with accompanying increases in nuclear levels of Smad3. Silencing of TAZ reversed the effects of FAT1 depletion thus connecting inactivation of TAZ-TGFbeta signalling with Hippo signalling mediated through FAT1. These findings establish FAT1 as a new upstream Hippo element regulating early stages of differentiation in neuronal cells.

The transmission of symmetric 40 Gb/s TWDM-based NG-PON2 utilizing delay interferometer (DI) for RSOA bandwidth enhancement

NASA Astrophysics Data System (ADS)

Bindhaiq, Salem; Zulkifli, Nadiatulhuda; Supa'at, AbuSahmah M.

2016-07-01

Time and wavelength-division multiplexed passive optical network (TWDM-PON) has been finally selected as the pragmatic solution for the next-generation passive optical network stage 2 (NG-PON2). In this paper, we propose a symmetric 40 Gb/s TWDM-PON system with low cost reflective semiconductor optical amplifier (RSOA) for both downstream and upstream directions. A single bi-pass delay interferometer (DI), deployed in the optical line terminal (OLT), is used to enhance the poor performance of the RSOA with respect to the low bandwidth induced by laser chirp. With the help of the 40 GHz free spectrum range (FSR) DI, we show a successful transmission of the proposed work through simulation study where an aggregate capacity of 40 Gb/s is transported over 40 km transmission distance with 32 splits. The TWDM-PON system at BER of 10-6 has shown a minimum receiver sensitivity of -22.78 dBm and -22.71 dBm for both downstream and upstream, respectively with maximum power penalty of 2 dB for downstream channel and 2.39 dB for upstream channel.

Three-dimensional analysis of the Pratt and Whitney alternate design SSME fuel turbine

NASA Technical Reports Server (NTRS)

Kirtley, K. R.; Beach, T. A.; Adamczyk, J. J.

1991-01-01

The three dimensional viscous time-mean flow in the Pratt and Whitney alternate design space shuttle main engine fuel turbine is simulated using the average passage Navier-Stokes equations. The migration of secondary flows generated by upstream blade rows and their effect on the performance of downstream blade rows is studied. The present simulation confirms that the flow in this two stage turbine is highly three dimensional and dominated by the tip leakage flow. The tip leakage vortex generated by the first blade persists through the second blade and adversely affects its performance. The greatest mixing of the inlet total temperature distortion occurs in the second vane and is due to the large leakage vortex generated by the upstream rotor. It is assumed that the predominant spanwise mixing mechanism in this low aspect ratio turbine is the radial transport due to the deterministically unsteady vortical flow generated by upstream blade rows. A by-product of the analysis is accurate pressure and heat loads for all blade rows under the influence of neighboring blade rows. These aero loads are useful for advanced structural analysis of the vanes and blades.

Low-carbon, low-water scenarios with life cycle water factors for ES&T paper

EPA Pesticide Factsheets

The dataset includes all data used in the creation of figures and graphs in the paper: Scenarios for low carbon and low water electric power plant operations: implications for upstream water use. Data includes regional electricity mixes, full life cycle water use, and water use for each life cycle stage. These encompass a range of scenarios out to 2050, and should not be used as predictions, forecasts or official baselines. The scenarios and results are for research purposes only, and do not represent current or future U.S. EPA policies or regulations.This dataset is associated with the following publication:Dodder , R., J. Barnwell , and W. Yelverton. Scenarios for low carbon and low water electric power plant operations: implications for upstream water use. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA, 50(21): 11460-11470, (2016).

Prevalence of the middle mesial canal in non surgical root canal treated mandibular first and second molars in a local military population

DTIC Science & Technology

2016-06-13

unless the clinician is careful to identify it. Missing this canal can contribute to a sequelae of persistent disease that may require the retreatment of...likelihood of finding MM canals. This is likely due to the fact that root canal retreatments are done on an older patient at a higher rate in the...canal. However, missing a canal can lead to continued pain and discomfort to the patient and other sequelae that may require nonsurgical retreatment

Submarine Alkalic Lavas Around the Hawaiian Hotspot; Plume and Non-Plume Signatures Determined by Noble Gases

NASA Astrophysics Data System (ADS)

Hanyu, T.; Clague, D. A.; Kaneoka, I.; Dunai, T. J.; Davies, G. R.

2004-12-01

Noble gas isotopic ratios were determined for submarine alkalic volcanic rocks distributed around the Hawaiian islands to constrain the origin of such alkalic volcanism. Samples were collected by dredging or using submersibles from the Kauai Channel between Oahu and Kauai, north of Molokai, northwest of Niihau, Southwest Oahu, South Arch and North Arch volcanic fields. Sites located downstream from the center of the hotspot have 3He/4He ratios close to MORB at about 8 Ra, demonstrating that the magmas erupted at these sites had minimum contribution of volatiles from a mantle plume. In contrast, the South Arch, located upstream of the hotspot on the Hawaiian Arch, has 3He/4He ratios between 17 and 21 Ra, indicating a strong plume influence. Differences in noble gas isotopic characteristics between alkalic volcanism downstream and upstream of the hotspot imply that upstream volcanism contains incipient melts from an upwelling mantle plume, having primitive 3He/4He. In combination with lithophile element isotopic data, we conclude that the most likely source of the upstream magmatism is depleted asthenospheric mantle that has been metasomatised by incipient melt from a mantle plume. After major melt extraction from the mantle plume during production of magmas for the shield stage, the plume material is highly depleted in noble gases and moderately depleted in lithophile elements. Partial melting of the depleted mantle impregnated by melts derived from this volatile depleted plume source may explain the isotopic characteristics of the downstream alkalic magmatism.

Root canal preparation of mandibular molars with 3 nickel-titanium rotary instruments: a micro-computed tomographic study.

PubMed

Zhao, Dan; Shen, Ya; Peng, Bin; Haapasalo, Markus

2014-11-01

The aim of this study was to describe the canal shaping properties of ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Universal (PTU; Dentsply Tulsa Dental Specialties, Johnson City, TN), and WaveOne (Dentsply Maillefer) nickel-titanium instruments in mandibular first molars by using micro-computed tomographic (micro-CT) scanning. A total of 36 maxillary first molars with 2 separate mesial canals and 1 distal canal were selected and scanned preoperatively and postoperatively by using micro-CT scanning with a voxel size of 30 μm. Canals were prepared with PTU, PTN, and WaveOne systems under hypochlorite irrigation. The volume of the untreated canal; the volume of dentin removed after preparation; the amount of the uninstrumented area; and the transportation to the coronal, middle, and apical thirds of canals were measured. The preparation time and instrument failure were also recorded. Instrumentation of canals increased their volume and surface area. The distal canals had a significantly higher proportion of unprepared surfaces than mesial canals (P < .05). The PTN system produced less transportation than the WaveOne and PTU systems in the apical third of the mesial canals (P < .05). There was no significant difference on apical transportation in distal canals among the 3 instrument systems. Instrumentation with WaveOne was significantly faster than with the other 2 instruments (P < .05). The PTN, PTU, and WaveOne instruments shaped root canals in mandibular first molars in vitro without significant shaping errors. The curved canals prepared using PTN had less apical transportation than the canals prepared using WaveOne and PTU. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Canal Transportation and Centering Ability of ProTaper and SafeSider in Preparation of Curved Root Canals: A CBCT Evaluation

PubMed Central

Delgoshayi, Negar; Abbasi, Mansoure; Bakhtiar, Hengameh; Sakhdari, Shirin; Ghannad, Setareh; Ellini, Mohammad Reza

2018-01-01

Introduction: Maintaining the original central canal path is an important parameter in efficient root canal preparation. Instruments causing minimal changes in original canal path are preferred for this purpose. This study sought to compare canal transportation and centering ability of ProTaper and SafeSider instruments in curved mesiobuccal root canals of mandibular first molars using cone beam computed tomography (CBCT). Methods and Materials : In this experimental study, 30 mesiobuccal root canals of extracted human mandibular first molars with 20° to 40° curvature were randomly divided into two groups (n=15). After mounting in putty, preoperative CBCT scans were obtained of teeth. Root canals in group A were shaped using S1, S2, F1 and F2 of ProTaper system. Root canals in group B were instrumented to size 25 using SafeSider system according to the manufacturers’ instructions. Postoperative CBCT scans were then obtained. The distance between the external root surface and internal canal wall was measured at the mesial and distal at 1, 3 and 7 mm from the apex. The values measured on primary and secondary CBCT scans were compared to assess possible changes in original central canal path and canal transportation. Data were compared using the t-test and repeated measure ANOVA. Results: ProTaper and SafeSider were significantly different in terms of canal transportation and centering ability, and ProTaper was significantly superior to SafeSider in this respect (P<0.001). Conclusion: ProTaper (in contrast to SafeSider) is well capable of maintaining the original central canal path with the least amount of transportation. PMID:29707022

First Branchial Cleft Fistula Associated with External Auditory Canal Stenosis and Middle Ear Cholesteatoma

PubMed Central

Abdollahi fakhim, Shahin; Naderpoor, Masoud; Mousaviagdas, Mehrnoosh

2014-01-01

Introduction: First branchial cleft anomalies manifest with duplication of the external auditory canal. Case Report: This report features a rare case of microtia and congenital middle ear and canal cholesteatoma with first branchial fistula. External auditory canal stenosis was complicated by middle ear and external canal cholesteatoma, but branchial fistula, opening in the zygomatic root and a sinus in the helical root, may explain this feature. A canal wall down mastoidectomy with canaloplasty and wide meatoplasty was performed. The branchial cleft was excised through parotidectomy and facial nerve dissection. Conclusion: It should be considered that canal stenosis in such cases can induce cholesteatoma formation in the auditory canal and middle ear. PMID:25320705

First branchial cleft fistula associated with external auditory canal stenosis and middle ear cholesteatoma.

PubMed

Abdollahi Fakhim, Shahin; Naderpoor, Masoud; Mousaviagdas, Mehrnoosh

2014-10-01

First branchial cleft anomalies manifest with duplication of the external auditory canal. This report features a rare case of microtia and congenital middle ear and canal cholesteatoma with first branchial fistula. External auditory canal stenosis was complicated by middle ear and external canal cholesteatoma, but branchial fistula, opening in the zygomatic root and a sinus in the helical root, may explain this feature. A canal wall down mastoidectomy with canaloplasty and wide meatoplasty was performed. The branchial cleft was excised through parotidectomy and facial nerve dissection. It should be considered that canal stenosis in such cases can induce cholesteatoma formation in the auditory canal and middle ear.

Experimental investigation on laser-induced plasma ignition of hydrocarbon fuel in scramjet engine at takeover flight conditions

NASA Astrophysics Data System (ADS)

Li, Xipeng; Liu, Weidong; Pan, Yu; Yang, Leichao; An, Bin

2017-09-01

Laser-induced plasma ignition of an ethylene fuelled cavity is successfully conducted in a model scramjet engine combustor with dual cavities. The simulated flight condition corresponds to takeover flight Mach 4, with isolator entrance Mach number of 2.1, the total pressure of 0.65 MPa and stagnation temperature of 947 K. Ethylene is injected 35 mm upstream of cavity flameholder from four orifices with 2-mm-diameter. The 1064 nm laser beam, from a Q-switched Nd:YAG laser source running at 10 Hz and 940 mJ per pulse, is focused into cavity for ignition. High speed photography is used to capture the transient ignition process. The laser-induced gas breakdown, flame kernel generation and propagation are all recorded and ensuing stable supersonic combustion is established in cavity. The highly ionized plasma zone is almost round at starting, and then the surface of the flame kernel is wrinkled severely in 150 μs after the laser pulse due to the strong turbulence flow in cavity. The flame kernel is found rotating anti-clockwise and gradually moves upstream as the entrainment of circulation flow in cavity. The flame is stabilized at the corner of the cavity for about 200 μs, and then spreads from leading edge to trailing edge via the under part of shear layer to fully fill the entire cavity. The corner recirculation zone of cavity is of great importance for flame spreading. Eventually, a cavity shear-layer stabilized combustion is established in the supersonic flow roughly 2.9 ms after the laser pulse. Both the temporal evolution of normalized chemiluminescence intensity and normalized flame area show that the entire ignition process can be divided into four stages, which are referred as turbulent dissipation stage, combustion enhancement stage, reverting stage and combustion stabilization stage. The results show promising potentials of laser induced plasma for ignition in real scramjets.

A comparison of instrumentation using Naviflex and Profile nickel-titanium engine-driven rotary instruments.

PubMed

Ottosen, S R; Nicholls, J I; Steiner, J C

1999-06-01

This study was designed to compare the changes in canal configuration resulting from instrumentation by either Profile or Naviflex instruments. Forty mesial canals in extracted human molar teeth were embedded and sectioned at two root levels. Reassembled teeth were instrumented with a modified crown-down technique as described in the Profile training video for Profile files and in a similar manner for Naviflex instruments. Superimposed pre- and postinstrumented cross-sectional root images were projected, traced, and scanned into a computer for analysis. Canal movement, in relation to the furca, and canal area change were recorded. The results showed no significant difference in canal center movement or canal area change between the Profile or Naviflex groups. The degree of canal curvature had no effect on canal center movement or canal area change.

Retrospective Study of Root Canal Configurations of Mandibular Third Molars Using CBCT- Part-II.

PubMed

Somasundaram, Pavithra; Rawtiya, Manjusha; Wadhwani, Shefali; Uthappa, Roshan; Shivagange, Vinay; Khan, Sheeba

2017-06-01

Abnormal root canal morphologies of third molars can be diagnostically and technically challenging during root canal treatment. The aim of this retrospective study was to investigate the root and canal morphology of mandibular third molars in Central India population by using Cone Beam Computed Tomography (CBCT) analysis. CBCT images of 171 mandibular third molars were observed and data regarding number of roots, number of canals, Vertucci's classification in each root, prevalence of C shaped canal, gender and topographical relation of morphology in mandibular third molar was statistically evaluated. Majority of mandibular third molars had two roots (84.2%) and three canals (64.3%). Most mesial root had Vertucci Type II (55.6%) and Vertucci Type IV (22.2%), distal root had Type I canals (87.5%). Over all prevalence of C shaped canals in mandibular third molars was 9.4%. There was a high prevalence of two rooted mandibular third molars with three canals.

Endodontic management of maxillary first molar with seven root canals diagnosed using Cone Beam Computed Tomography scanning

PubMed Central

Raghavendra, Srinidhi Surya; Hindlekar, Ajit Narayan; Desai, Niranjan Nanasaheb; Vyavahare, Nishant Kishor; Napte, Bandu Devrao

2014-01-01

The main objective of root canal treatment is thorough cleaning and shaping of the entire pulp space and its complete filling with an inert filling material. A major cause of post-treatment disease is the inability to locate, debride or adequately fill all canals of the root canal system. The form, configuration, and number of root canals in the maxillary first molars have been discussed for more than half a century. Maxillary first molars commonly present with three roots and three canals, with a second mesiobuccal canal (MB2) also present. With the advent of improved magnification there are reports of multiple root canals in the maxillary first molars. Nonsurgical endodontic therapy of a left maxillary first molar with three roots and seven root canals was successfully performed under a dental operating microscope. The diagnosis of multiple root canals was confirmed with the help of Cone Beam Computed Tomography (CBCT) images. PMID:25565745

Retrospective Study of Root Canal Configurations of Mandibular Third Molars Using CBCT- Part-II

PubMed Central

Somasundaram, Pavithra; Wadhwani, Shefali; Uthappa, Roshan; Shivagange, Vinay; Khan, Sheeba

2017-01-01

Introduction Abnormal root canal morphologies of third molars can be diagnostically and technically challenging during root canal treatment. Aim The aim of this retrospective study was to investigate the root and canal morphology of mandibular third molars in Central India population by using Cone Beam Computed Tomography (CBCT) analysis. Materials and Methods CBCT images of 171 mandibular third molars were observed and data regarding number of roots, number of canals, Vertucci’s classification in each root, prevalence of C shaped canal, gender and topographical relation of morphology in mandibular third molar was statistically evaluated. Results Majority of mandibular third molars had two roots (84.2%) and three canals (64.3%). Most mesial root had Vertucci Type II (55.6%) and Vertucci Type IV (22.2%), distal root had Type I canals (87.5%). Over all prevalence of C shaped canals in mandibular third molars was 9.4%. Conclusion There was a high prevalence of two rooted mandibular third molars with three canals. PMID:28764294

8. VIEW SHOWING THE DEMOSSING OF GRAND CANAL LOCATION UNKNOWN. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. VIEW SHOWING THE DEMOSSING OF GRAND CANAL LOCATION UNKNOWN. AT TEAM OF HORSES ON OPPOSITE BANKS OF THE CANAL DRAG A CHAIN BETWEEN THEM ALONG THE BOTTOM OF THE CANAL, WHICH PULLS THE MOSS AND WEEDS LOOSE. THE PLANS THEN FLOAT DOWN THE CANAL AND ARE CAUGHT IN A SCREEN AND REMOVED. Photographer unknown, 1923 - Grand Canal, North side of Salt River, Tempe, Maricopa County, AZ

Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography

PubMed Central

Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

2015-01-01

Background Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Material/Methods Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. Results ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Conclusions Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal. PMID:26092929

Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography.

PubMed

Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

2015-06-20

Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal.

Micro-computed tomography evaluation of the preparation of long oval root canals in mandibular molars with the self-adjusting file.

PubMed

Paqué, Frank; Peters, Ove A

2011-04-01

The aim of this study was to assess the shaping potential of a novel nickel-titanium instrument, the self-adjusting file (SAF), in long oval root canals in distal roots in mandibular molars. Twenty mandibular molars with long oval distal root canals were selected and scanned preoperatively and postoperatively by using micro-computed tomography at an original resolution of 20 μm. Canals were shaped with the SAF, three-dimensionally reconstructed, and evaluated for volume, surface area, canal transportation, and prepared surface. Data were statistically contrasted by using paired t tests and regression analysis. Preoperatively, canal volume was 7.73 ± 2.13 mm(3), and canal area was 42.83 ± 8.14 mm(2). Volumes and surface areas increased significantly (P < .001) by 4.84 ± 1.73 mm(3) and 3.34 ± 1.73 mm(2), respectively, and no gross preparation errors were detected. Unprepared canal surface varied between individual canals, and mean unprepared surface was 23.5% ± 8.9%. Prepared areas were significantly larger compared with rotary canal preparation done in a previous study. Canal transportation scores were higher in the coronal root canal third (106 ± 50 μm) compared with the apical third (81 ± 49 μm). In vitro, preparation of long oval-shaped root canals in mandibular molars with the SAF was effective and safe. Moreover, shapes generated with the SAF were more complete compared with rotary canal preparation. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Saphenous and Infrapatellar Nerves at the Adductor Canal: Anatomy and Implications in Regional Anesthesia.

PubMed

Anagnostopoulou, Sofia; Anagnostis, George; Saranteas, Theodosios; Mavrogenis, Andreas F; Paraskeuopoulos, Tilemachos

2016-01-01

Conflicting data exist regarding the anatomical relationship of the saphenous and infrapatellar nerves at the adductor canal and the location of the superior foramen of the canal. Therefore, the authors performed a cadaveric study to detail the relationship and course of the saphenous and infrapatellar nerves and the level of the superior foramen of the canal. The adductor canal and subsartorial compartment were dissected in 17 human cadavers. The distance between the superior foramen of the canal and the mid-distance (MD) between the base of the patella and the anterior superior iliac crest were measured; the course of the saphenous and infrapatellar nerves and the level of origin of the infrapatellar branch were detailed. In 13 of 17 specimens, the superior foramen of the adductor canal was distal to the MD (mean, 6.5 cm); in the remaining specimens, it was proximal to the MD. In 12 of 17 specimens, the infrapatellar branch exited the canal separately from the saphenous nerve; in the remaining specimens, it originated caudally to the canal. In all dissections, the infrapatellar branch had a constant course in close proximity to the saphenous nerve within the canal and between the sartorious muscle and femoral artery caudally to the canal. Most commonly, the superior foramen of the adductor canal is located caudally to the MD; the infrapatellar branch originates from the saphenous nerve within the canal and has a constant course in close proximity to the saphenous nerve. These observations should be considered for regional anesthesia techniques at the adductor canal. Copyright 2016, SLACK Incorporated.

Middle mesial canals in mandibular molars: incidence and related factors.

PubMed

Nosrat, Ali; Deschenes, Raney J; Tordik, Patricia A; Hicks, M Lamar; Fouad, Ashraf F

2015-01-01

Although the internal anatomy of mandibular molars has been extensively studied, information about middle mesial (MM) canals is limited. The primary aim of this retrospective study was to evaluate the incidence of MM canals in mandibular first and second molars. The secondary aim was to correlate the incidence of MM canals with variables of molar type, sex, age, ethnicity, and presence of a second distal canal. All mature permanent first and second mandibular molars treated from August 2012 to May 2014 were included in the analysis. After completion of root canal instrumentation in all main canals, the clinician inspected the isthmus area of the mesial root using the dental operating microscope. If there was a catch point in this area with a file or explorer, the operator spent more time attempting to negotiate an MM canal. Seventy-five mandibular first and second molars were treated during the specified period. Fifteen (20%) teeth had negotiable MM canals. The incidence of MM canals was 32.1% in patients ≤ 20 years old, 23.8% in patients 21-40 years old, and 3.8% in patients > 40 years. Analysis of data revealed a significant difference in the distribution of MM canals among different age groups (P < .05). The differences in the distribution of MM canals based on sex, ethnicity, molar type, and presence of a second distal canal were not significant. The incidence of negotiable MM canals overall and their frequency of identification in younger patients were higher than in previous reports. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Impact of cross-sectional root canal shape on filled canal volume and remaining root filling material after retreatment.

PubMed

Rechenberg, D K; Paqué, F

2013-06-01

To assess the impact of cross-sectional root canal shape (CSRCS) on the canal volume that can be filled and the root filling material that remains following a subsequent retreatment procedure. A total of 15 extracted two-rooted human maxillary premolars and 15 mandibular first molars were used. Both root canals in the premolars (N = 30) and the distal root canal in the molars (N = 15) were prepared using ProFile instruments and filled by lateral compaction using gutta-percha and AH Plus sealer. Canals were later retreated using the last ProFile used for instrumentation followed by two ProFiles of increasing size. Teeth were viewed in a μCT scanner before and after each treatment step. Defined and validated threshold levels were used to differentiate empty root canal volumes, root dentine and root filling materials from each other. CSRCS was defined as the averaged ratio between bucco-lingual and mesio-distal canal diameter (round ≤ 1, oval 1-2, long oval 2-4 and flattened ≥ 4), determined for each 1 mm over the total root length. Data were averaged between the two canals in premolars, only the distal canals were assessed in molars. Parametric and non-parametric tests were used to statistically compare the data, alpha = 0.01. Canals in premolars had a round CSRCS after preparation (1.0 ± 0.0), whereas distal counterparts in molars were oval (1.6 ± 0.5). Significantly (P < 0.01) more canal volume could be filled, and significantly less filling material remained after retreatment in premolars compared with mandibular molar distal canals. There was a high correlation between CSRCS, filled canal volume and remaining filling material. The endodontic procedures under investigation were significantly influenced by the cross-sectional root canal shape. © 2012 International Endodontic Journal. Published by Blackwell Publishing Ltd.

Root anatomy and canal configuration of the permanent mandibular first molar: a systematic review.

PubMed

de Pablo, Oliver Valencia; Estevez, Roberto; Péix Sánchez, Manuel; Heilborn, Carlos; Cohenca, Nestor

2010-12-01

The main goal of endodontic therapy is to prevent or heal apical periodontitis. However, root canal anatomy might present a clinical challenge directly related to the treatment outcome. The purpose of this study was to review published literature related to root anatomy and root canal configuration of the permanent mandibular first molar. An exhaustive search was undertaken to identify published literature related to the root anatomy and root canal morphology of the permanent mandibular first molar by using key words. The search of the MEDLINE database included all publications from 1966-May 2010. Selected articles were then obtained and reviewed. Data evaluated and summarized in the data sheet included methodology, population, number of teeth per study (power), number of root canals, type of root canal configuration, and identification of number of apical foramina. Forty-one studies were identified including a total of 18,781 teeth. The incidence of a third root was 13% and was strongly correlated with the ethnicity of the studied population. Three canals were present in 61.3%, 4 canals in 35.7%, and 5 canals in approximately 1%. Root canal configuration of the mesial root revealed 2 canals in 94.4% and 3 canals in 2.3%. The most common canal system configuration was Vertucci type IV (52.3%), followed by type II (35%). Root canal configuration of the distal root revealed type I configuration in 62.7%, followed by types II (14.5%) and IV (12.4%). The presence of isthmus communications averaged 54.8% on the mesial and 20.2% on the distal root. The number of roots on the mandibular first molar is directly related to ethnicity. Root canal morphology and configuration might present the clinician with a complex anatomy requiring more diagnostic approaches, access modifications, and clinical skills to successfully localize, negotiate, disinfect, and seal the root canal system. Crown Copyright © 2010. Published by Elsevier Inc. All rights reserved.

88. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

88. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF FILER, IDAHO; WEST VIEW OF CANAL AND GATES. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

97. POINT SPILL, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

97. POINT SPILL, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY NORTHWEST OF MURTAUGH, IDAHO; OVERALL WEST VIEW FROM CANAL SIDE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

149. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

149. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER DAM; CLOSE-UP OF MAIN CANAL GATES, SOUTH VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

91. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

91. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF FILER, IDAHO; NORTHEAST VIEW OF CANAL AND GATES. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

89. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

89. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF FILER, IDAHO; OUTLET SIDE OF CANAL, SOUTHWEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

3. Dundee Canal looking northwest from north of Dundee Textile ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. Dundee Canal looking northwest from north of Dundee Textile Company Mill - Dundee Canal Industrial Historic District, Beginning at George Street in Passaic & extending north along Dundee Canal approximately 1.2 miles to Canal headgates opposite East Clifton Avenue in Clifton, Passaic, Passaic County, NJ

Intermittency Models and Spot Measurements

NASA Technical Reports Server (NTRS)

Ashworth, D. A.

2007-01-01

Experimental work at the University of Oxford Osney Lab has demonstrated characteristics of the late-stage transition process by the use of thin-film heat transfer gauges. The development of turbulent spots has been observed in a range of environments, including flat plates, turbine blade cascade tests and wake-passing experiments. These results were taken at Mach/Reynolds numbers and gas-to-wall temperature ratios representative of gas turbines. Analyses of the spot characteristics are consistent with measurements taken in low speed experiments, and support the Schubauer and Klebanoff type of turbulent spots. The addition of simulated wakes from upstream stages has been observed to be primarily superpositional for these tests.

Disinfection of Contaminated Canals by Different Laser Wavelengths, while Performing Root Canal Therapy

PubMed Central

Asnaashari, Mohammad; Safavi, Nassimeh

2013-01-01

Removal of smear layer and disinfection of canals are important objectives of teeth root canal cleaning. In order to achieve this purpose, rinsing substances, intra canal drugs as well as ultrasound are used. Today, use of laser to remove smear layer and to disinfect root canals has increasingly attracted the attentions. Till now different lasers such as CO2, Nd:YAG, Er:YAG, Er,Cr:YSGG have been used for debris and smear removal from the canals. Numerous studies have shown that Er:YAG is the most appropriate laser for intra canal debris and smear removal. In addition different laser wavelengths have been used directly or as an adjunctive to disinfect canals. Laser light can penetrate areas of canals where irrigating and disinfecting solutions cannot reach, like secondary canals and deep dentinal tubules and also can eliminate microorganisms. Different studies have confirmed the penetration of Nd:YAG laser in deep dentin and reduction of microorganisms penetration. But studies on comparison of antibacterial effects of Nd:YAG laser with sodium hypochlorite showed effectiveness of both, with a better effect for sodium hypochlorite. Studies performed in relation with anti-microbial effects of Diode laser with various parameters show that this laser can be effective in reducing intra canal bacterial count and penetration in the depth of 500 microns in dentin. In studies performed on Diode laser in combination with canal irrigating solutions such as sodium hypochlorite and oxygenated water better results were obtained. Although studies on disinfection by the Erbium laser family show that use of this laser alone can be effective in disinfecting canals, studies evaluating the disinfecting effects of this laser and different concentrations of sodium hypochlorite show that the latter alone is more effective in disinfecting canals. And better results were obtained when Erbium laser was used in combination with sodium hypochlorite irrigating solution in canals. Results of the aforementioned articles indicate that this laser is effective in combination with a rinsing solution such as sodium hypochlorite. Results from studies including several types of the different Er:YAG, Ho:YAG, Nd:YAG, Er,Cr:YSGG lasers in disinfecting canals showed that all wavelengths used in disinfection for different thicknesses of dentin were efficacious without damaging thermal effect. Considering that use of different lasers in canals can be accompanied with temperature increase which can sometimes lead to damages to teeth and surrounding tissues, thus the use of photochemical phenomenon for elimination of microorganisms have attracted attention of many researchers. Studies in this field imply the efficacy of this method in reducing canal bacterial count and recommend its use as an adjunctive after biomechanical preparation of canals. Results from performed studies show removal of intra canal debris and smear layer by different lasers and particularly the Erbium laser family. Furthermore various laser wavelengths, particularly of Diode and Nd:YAG lasers can be effective in reducing intra canal microbial count. Maximum effect is obtained when laser light is used in canals in combination with sodium hypochlorite irrigating substance in appropriate concentration. Therefore use of laser energy can improve success rate of root canal treatments. PMID:25606301

123. MCMULLEN CREEK, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

123. MCMULLEN CREEK, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; SOUTH VIEW OF THE CREEK EMPTYING INTO THE HIGH LINE CANAL. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

189. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

189. Photocopy of drawing, Twin Falls Canal Company, date unknown. ROCK CREEK CROSSING, LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

94. CEDAR DRAW SPILL, LOW LINE CANAL, TWIN FALLS COUNTY ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

94. CEDAR DRAW SPILL, LOW LINE CANAL, TWIN FALLS COUNTY SOUTH OF FILER, IDAHO; CLOSE-UP OF GATES FROM THE CANAL SIDE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

131. FORKS DIVERSION, HIGH LINE AND LOW LINE CANALS, TWIN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

131. FORKS DIVERSION, HIGH LINE AND LOW LINE CANALS, TWIN FALLS COUNTY, SOUTH OF HANSEN, IDAHO; INLET SIDE OF LOW LINE CANAL, WEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

75 FR 39632 - Regulated Navigation Area; Gulf Intracoastal Waterway, Inner Harbor Navigation Canal, Harvey...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-12

..., Algiers Canal, New Orleans, LA; Correction ACTION: Interim rule; Correction. SUMMARY: In the Federal... Area; Gulf Intracoastal Waterway, Inner Harbor Navigation Canal, Harvey Canal, Algiers Canal, New Orleans, LA into the Code of Federal Regulations. That publication contained an error in the DATES section...

Endodontic management of mesiobuccal-2 canal in four-rooted and five-canalled mandibular third molar.

PubMed

Garg, Amit Kumar; Bhardwaj, Anuj; Mantri, Vijay R; Agrawal, Neha

2014-05-01

A case of unusual Root morphology is presented to demonstrate anatomic variations in mandibular third molar. The most common configuration of mandibular third molar is two Roots and three canals; however they may have many different combinations. Endodontic treatment was performed in mandibular third molar having aberrant anatomy. Four Root canal orifices were located with the aid of dental operating microscope (DOM) and three separate Roots were diagnosed with radiographs. Spiral computed tomography (SCT) showed the presence of an extra canal and extra Root, indicating a rare anatomic configuration. Looking for additional canals and Roots are important part of successful endodontics, as the knowledge of their existence enable clinicians to treat a case successfully that otherwise might end in failure. The use of DOM and SCT in this case greatly contributed toward making a confirmatory diagnosis and successful endodontic treatment of four-rooted and five-canalled mandibular third molar. Variation in Root canal anatomy is very common. Knowledge of these variations is very essential for successful Root canal outcome, inability to do so can lead to missed canals and failures. Hence, thorough knowledge of Root canal anatomy and advances in diagnostic aids are essential.

INTERNAL ROOT MORPHOLOGY IN MANDIBULAR FIRST PERMANENT MOLARS IN A KENYAN POPULATION.

PubMed

Muriithi, N J; Maina, S W; Okoth, J; Gathece, L W

2012-05-01

To determine the internal root morphology and gender variations in mandibular first permanent molars in a Kenyan population. In vitro descriptive cross sectional study. School of Dental Sciences, University of Nairobi The mesial root of mandibular first molars had two canals in 96.3% of the teeth in both males and females and-type IV canal configuration was most prevalent in the mesial root. The distal root of the mandibular first molar had one canal in 57.7% of the teeth in males and females. There were significant gender variations in the number of canals and canal configurations in the distal root. Two canals were more prevalent in females (53.6%) compared to males (30.4%) and a single canal was more frequent in males (69.6%) compared to females (46.4%) (P=0.001). Canal types 1, 11 and IV were the most frequent in the mandibular distal root. The gender variation in the frequency of canal types I, II and IV in the distal root was statistically significant (P=0.001). Most of the mandibular first molars have three canals (56%). Two canals in the distal root are more frequent among females (53.6%) compared to males (30.4%).

Earth observations taken during STS-98 mission

NASA Image and Video Library

2001-02-07

STS098-712-091 (7-20 February 2001) --- The forested area of the Panama Canal Zone can be seen near the center of this north-looking image, photographed with a 70mm handheld camera from the Earth-orbiting Space Shuttle Atlantis. (NOTE: The image should be oriented with Panama running horizontally and the majority of the clouds at the top). The Panama Canal Zone extends 5 miles (8 kilometers) on either side of the Panama Canal. The forested zone acts as a buffer for the canal to help prevent erosion and sediment from clogging the canal. Most of the countryside on both sides of the Canal Zone has been deforested to make way for large ranches and the raising of cattle. Though some sedimentation is occurring, dredging of the canal keeps the passage clear. The Panama Canal is 40 miles (64 kilometers) long including dredged approach channels at each end. With the Caribbean Sea covering the upper portion of the image and the Pacific Ocean covering the lower portion of the image, the canal traverses the Isthmus of Panama in a northwest to southeast direction. Gatun Lake, one of the largest artificial lakes in the world, is visible at the north end of the Canal Zone. Panama City (light-colored grayish area) is discernible to the right of the canal at its southern entrance from the Pacific Ocean. In 1996, 15,000 ships traveled through the canal, an average of 42 ships per day. Passage through the canal requires 7 to 8 hours.

Cone-beam computed tomography as advanced diagnostic aid in endodontic treatment of molars with multiple canals: Two case reports

PubMed Central

Kamble, Amit Pralhad; Pawar, Rohini Rangarao; Mattigatti, Sudha; Mangala, T. M.; Makandar, Saleem

2017-01-01

The purpose of these case reports is to emphasize the importance of knowledge regarding the root canal morphology and current diagnostic aids one should have as both of these important factors going to affect the prognosis of the endodontic treatment. These two case reports describe the maxillary and mandibular first molars with multiple canals. After clinical and radiographic diagnosis, additional help of cone-beam computed tomography (CBCT) of mandibular molar has been taken to evaluate the morphology and canal pattern; while maxillary molar was evaluated using CBCT scan to evaluate the canal configuration and obturation. In CBCT evaluation, the mandibular molar was diagnosed with six separated canals with three mesial and three distal canals and with radix paramolaris and radix entomolaris. The maxillary molar had five canals with three mesiobuccal (MB) canals. Both molars were instrumented with conventional hand and rotary file systems and obturated by conventional lateral compaction method. The axial images from CBCT show Vertucci Type VIII canal pattern in both roots of first mandibular molars and in MB root of maxillary first molar Sert and Bayirli Type XVIII canal configuration and no accessory canal in distobuccal and palatal root. With the recent innovations in diagnostic and operating aids, we can come across many variations in the root canal morphology of both mandibular and maxillary teeth, especially multi-rooted one (i.e., molars), and the knowledge of which leads to successful endodontic treatment with an excellent prognosis. PMID:29259367

Internal carotid arterial canal size and scaling in Euarchonta: Re-assessing implications for arterial patency and phylogenetic relationships in early fossil primates.

PubMed

Boyer, Doug M; Kirk, E Christopher; Silcox, Mary T; Gunnell, Gregg F; Gilbert, Christopher C; Yapuncich, Gabriel S; Allen, Kari L; Welch, Emma; Bloch, Jonathan I; Gonzales, Lauren A; Kay, Richard F; Seiffert, Erik R

2016-08-01

Primate species typically differ from other mammals in having bony canals that enclose the branches of the internal carotid artery (ICA) as they pass through the middle ear. The presence and relative size of these canals varies among major primate clades. As a result, differences in the anatomy of the canals for the promontorial and stapedial branches of the ICA have been cited as evidence of either haplorhine or strepsirrhine affinities among otherwise enigmatic early fossil euprimates. Here we use micro X-ray computed tomography to compile the largest quantitative dataset on ICA canal sizes. The data suggest greater variation of the ICA canals within some groups than has been previously appreciated. For example, Lepilemur and Avahi differ from most other lemuriforms in having a larger promontorial canal than stapedial canal. Furthermore, various lemurids are intraspecifically variable in relative canal size, with the promontorial canal being larger than the stapedial canal in some individuals but not others. In species where the promontorial artery supplies the brain with blood, the size of the promontorial canal is significantly correlated with endocranial volume (ECV). Among species with alternate routes of encephalic blood supply, the promontorial canal is highly reduced relative to ECV, and correlated with both ECV and cranium size. Ancestral state reconstructions incorporating data from fossils suggest that the last common ancestor of living primates had promontorial and stapedial canals that were similar to each other in size and large relative to ECV. We conclude that the plesiomorphic condition for crown primates is to have a patent promontorial artery supplying the brain and a patent stapedial artery for various non-encephalic structures. This inferred ancestral condition is exhibited by treeshrews and most early fossil euprimates, while extant primates exhibit reduction in one canal or another. The only early fossils deviating from this plesiomorphic condition are Adapis parisiensis with a reduced promontorial canal, and Rooneyia and Mahgarita with reduced stapedial canals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Shaping ability of NT Engine and McXim rotary nickel-titanium instruments in simulated root canals. Part 2.

PubMed

Thompson, S A; Dummer, P M

1997-07-01

The aim of this laboratory-based study was to determine the shaping ability of NT Engine and McXim nickel-titanium rotary instruments in simulated root canals. A total of 40 canals with four different shapes in terms of angle and position of curve were prepared with NT Engine and McXim instruments, using the technique recommended by the manufacturer. Part 2 of this report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and overall postoperative shape. Pre- and postoperative images of the canals were taken using a video camera attached to a computer with image analysis software. The pre- and postoperative views were superimposed to highlight the amount and position of material removed during preparation. No zips, elbows, perforations or danger zones were created during preparation. Forty-two per cent of canals had ledges on the outer aspect of the curve, the majority of which (16 out of 17) occurred in canals with short acute curves. There were significant differences (P < 0.001) between canal shapes in terms of the incidence of ledges. There were highly significant differences (P < 0.001) between the canal shapes in total canal width at specific points along the canal length and in the amount or resin removed from the inner and outer aspects of the curve. The direction of canal transportation at the end-point of preparation was most frequently towards the outer aspect of the curve, especially in canals with 40 degrees curves. At the beginning of the curve, transportation in the majority of canals was towards the inner aspect of the curve. Mean absolute transportation was less than 0.03 mm throughout the curve and towards the end-point, with significant differences between canal shapes occurring at the apex (P < 0.05) and at the beginning of the curve (P < 0.001). Under the conditions of this study, NT Engine and McXim rotary nickel-titanium instruments created no aberrations other than ledges and produced only minimal transportation. The overall shape of canals was good.

Use of a highly transparent zebrafish mutant for investigations in the development of the vertebrate auditory system (Conference Presentation)

NASA Astrophysics Data System (ADS)

Wisniowiecki, Anna M.; Mattison, Scott P.; Kim, Sangmin; Riley, Bruce; Applegate, Brian E.

2016-03-01

Zebrafish, an auditory specialist among fish, offer analogous auditory structures to vertebrates and is a model for hearing and deafness in vertebrates, including humans. Nevertheless, many questions remain on the basic mechanics of the auditory pathway. Phase-sensitive Optical Coherence Tomography has been proven as valuable technique for functional vibrometric measurements in the murine ear. Such measurements are key to building a complete understanding of auditory mechanics. The application of such techniques in the zebrafish is impeded by the high level of pigmentation, which develops superior to the transverse plane and envelops the auditory system superficially. A zebrafish double mutant for nacre and roy (mitfa-/- ;roya-/- [casper]), which exhibits defects for neural-crest derived melanocytes and iridophores, at all stages of development, is pursued to improve image quality and sensitivity for functional imaging. So far our investigations with the casper mutants have enabled the identification of the specialized hearing organs, fluid-filled canal connecting the ears, and sub-structures of the semicircular canals. In our previous work with wild-type zebrafish, we were only able to identify and observe stimulated vibration of the largest structures, specifically the anterior swim bladder and tripus ossicle, even among small, larval specimen, with fully developed inner ears. In conclusion, this genetic mutant will enable the study of the dynamics of the zebrafish ear from the early larval stages all the way into adulthood.

Human-induced hydrological changes and sinkholes in the gypsum karst of Lesina Marina area (Foggia Province, Italy)

NASA Astrophysics Data System (ADS)

Fidelibus, M. D.; Gutierrez, F.; Spilotro, G.

2009-04-01

The Lesina Lagoon is located in the East-West-trending northern cost of Gargano (southern Italy). The lagoon is fed by springs draining the northern side of the Gargano Mesozoic carbonate aquifer and is connected with the sea by three channels, including the 2.2 km long Acquarotta Canal with a N-S orientation. The sea-side mouth of this canal was frequently clogged by sand accumulation. In 1927, the path of the northern section of this canal was changed to improve the water exchange between the lagoon and the Adriatic Sea for environmental and fish-farming purposes. The new portion of the canal, 8.5 m wide and 1.5 m deep, was excavated in evaporite bedrock and in a small outcrop of igneous rocks situated in the coast that inhibits sand accumulation. The Acquarotta Canal conveys water in both directions depending on the relative water levels of the lagoon and the sea. Initially the reach of the canal dug in gypsum was lined with concrete, which was replaced in 1993 by gabions for scenery improvement. The northern reach of the canal is dug in Upper Triassic gypsiferous sediments of the Burano Anhydrite Formation. The evaporite bedrock is mantled by unconsolidated deposits a few meters thick, largely made up of loose sand. The exposures found in the banks of the canal and in some sinkholes reveal that the gypsum has a high density of dissolutional conduits and cavities. Locally, it also shows open fractures and brecciated structure (crackle, mosaic and chaotic packbreccias) caused by dissolution-induced collapse processes. These voids, either of solutional or mechanical origin, are partially filled with detrital sediments derived from the mantling deposits. These features seem to correspond to a paleokarst, probably developed at several depths controlled by different and much lower sea level stands during the Quaternary. The construction Acquarotta Canal has caused significant changes in the local hydrology. According to the piezometric series recorded at several points distributed over a large area around the canal and the results of numerical simulations, the main hydrological changes include: (1) Incorporation of new boundary conditions. The groundwater flow, previously controlled by the oscillating sea level and by the lagoon level, has been altered introducing a line of minimum potential along the canal. The water level in the canal oscillates according to the variations in the levels of the sea and the lagoon. (2) The gypsum bedrock that behaves as an anisotropic aquifer, is drained by a channel in which the flow, essentially controlled by the tidal regime, discharges two times a day towards the sea and towards the lagoon. (3) The canal that works as a drainage trench, has caused the lowering of the water table. The local distortion of the piezometric surface has modified the flow direction and increased the gradient and flow rate. At the flanks of the canal, the groundwater that used to flow towards the sea, now has been captured by the excavation and circulates towards the canal. The sense of this flow is influenced by the piezometric changes caused by the tidal variations. (4) As a consequence of the lowering of the water table (of the order of a few decimetres) near the banks of the canal, slow subhorizontal phreatic flows have been replaced by more rapid downward vadose flows. These hydrological changes have induced the reactivation-acceleration of internal erosion and collapse processes leading to the generation of a large number of sinkholes in the vicinity of the canal. The lowering in the water table involves an increase in the effective weight of the sediments previously situated in the saturated zone due to the loss of buoyancy. Additionally, downward vadose flows and more rapid water circulation in the saturated zone towards the canal favour the flushing out of the sediments filling voids and the downward migration of cover material towards the underlying paleokarst. Most likely the continuous oscillations of the piezometric level and the associated bidirectional changes of the groundwater flow in the vicinity of the canal play a relevant role in the internal erosion processes. The low cohesion of the sandy cover determines to a great extent the high speed at which suffosion processes and the generation-enlargement of sinkholes are taking place. Subsidence activity has affected the canal since its construction. To our knowledge, the first account of a sinkhole occurrence in the adjacent area corresponds to an official report dating back to 1990. The great majority of the sinkholes are located within the canal and on two relatively narrow bands situated on its flanks. The sinkholes tend to form clusters and alignments with a prevalent N145E orientation. The Lesina Marina residential area, whose construction in the western side of the canal started around 1980, is currently suffering from subsidence damage, including the occurrence of collapse sinkholes in streets, destruction of pathways and cracking of walls. Boreholes and geophysical surveys performed in the area reveal the presence of abundant cavities up to 9 m in height, cave fills and collapse breccias in the strongly karstified bedrock. Most of the depressions can be classified as cover suffosion and collapse sinkholes generated by the downward migration of the loose sandy cover through voids in the bedrock. The lack of basal support caused by piping may lead to the gradual settlement of the cover and/or its collapse through the development of failure planes. These sinkholes are typically less than 1 m across and 2-3 m deep at the initial stages. However, they typically grow very rapidly by mass wasting processes acting on their edges until they reach the repose angle of the detrital mantle. Consequently, clusters of small sinkholes tend to evolve into a smaller number of large depressions up to 20 m meters across resulting from the coalescence of several dolines. Some sinkholes are related to the breakdown of cavities situated within the bedrock. These bedrock and cover collapse sinkholes are generally deeper reaching up to 7 m in depth. Detailed surveys carried out in 1999, 2005 and 2007 indicate that the area affected by sinkholes is increasing exponentially. These data indicate that the subsidence area has increased at a mean rate of 1000 m2/year between 1999 and 2007. The spatio-temporal evolution pattern of the phenomenon strongly suggests that subsidence will affect to a progressively larger area in the future. Given the proximity of some buildings to rapidly growing sinkhole clusters, it seems highly probable that some structures will be severely damaged by subsidence. Restoring the original hydrological situation would help to reduce the sinkhole hazard. However, the rapid increase that is undergoing the rock mass permeability due to the reactivation of the paleokarst may hamper the effectiveness of this measure.

Multi-temporal surveys for microplastic particles enabled by a novel and fast application of SWIR imaging spectroscopy - Study of an urban watercourse traversing the city of Berlin, Germany.

PubMed

Schmidt, L Katharina; Bochow, Mathias; Imhof, Hannes K; Oswald, Sascha E

2018-08-01

Following the widespread assumption that a majority of ubiquitous marine microplastic particles originate from land-based sources, recent studies identify rivers as important pathways for microplastic particles (MPP) to the oceans. Yet a detailed understanding of the underlying processes and dominant sources is difficult to obtain with the existing accurate but extremely time-consuming methods available for the identification of MPP. Thus in the presented study, a novel approach applying short-wave infrared imaging spectroscopy for the quick and semi-automated identification of MPP is applied in combination with a multitemporal survey concept. Volume-reduced surface water samples were taken from transects at ten points along a major watercourse running through the South of Berlin, Germany, on six dates. After laboratory treatment, the samples were filtered onto glass fiber filters, scanned with an imaging spectrometer and analyzed by image processing. The presented method allows to count MPP, classify the plastic types and determine particle sizes. At the present stage of development particles larger than 450 μm in diameter can be identified and a visual validation showed that the results are reliable after a subsequent visual final check of certain typical error types. Therefore, the method has the potential to accelerate microplastic identification by complementing FTIR and Raman microspectroscopy. Technical advancements (e.g. new lens) will allow lower detection limits and a higher grade of automatization in the near future. The resulting microplastic concentrations in the water samples are discussed in a spatio-temporal context with respect to the influence (i) of urban areas, (ii) of effluents of three major Berlin wastewater treatment plants discharging into the canal and (iii) of precipitation events. Microplastic concentrations were higher downstream of the urban area and after precipitation. An increase in microplastic concentrations was discernible for the wastewater treatment plant located furthest upstream though not for the other two. Copyright © 2018 Elsevier Ltd. All rights reserved.

The success rate of bupivacaine and lidocaine as anesthetic agents in inferior alveolar nerve block in teeth with irreversible pulpitis without spontaneous pain.

PubMed

Parirokh, Masoud; Yosefi, Mohammad Hosein; Nakhaee, Nouzar; Abbott, Paul V; Manochehrifar, Hamed

2015-05-01

Achieving adequate anesthesia with inferior alveolar nerve blocks (IANB) is of great importance during dental procedures. The aim of the present study was to assess the success rate of two anesthetic agents (bupivacaine and lidocaine) for IANB when treating teeth with irreversible pulpitis. Sixty volunteer male and female patients who required root canal treatment of a mandibular molar due to caries participated in the present study. The inclusion criteria included prolonged pain to thermal stimulus but no spontaneous pain. The patients were randomly allocated to receive either 2% lidocaine with 1:80,000 epinephrine or 0.5% bupivacaine with 1:200,000 epinephrine as an IANB injection. The sensitivity of the teeth to a cold test as well as the amount of pain during access cavity preparation and root canal instrumentation were recorded. Results were statistically analyzed with the Chi-Square and Fischer's exact tests. At the final step, fifty-nine patients were included in the study. The success rate for bupivacaine and lidocaine groups were 20.0% and 24.1%, respectively. There was no significant difference between the two groups at any stage of the treatment procedure. There was no difference in success rates of anesthesia when bupivacaine and lidocaine were used for IANB injections to treat mandibular molar teeth with irreversible pulpitis. Neither agent was able to completely anesthetize the teeth effectively. Therefore, practitioners should be prepared to administer supplemental anesthesia to overcome pain during root canal treatment.

Conventional root canal therapy of C-shaped mandibular second molar. A case report.

PubMed

Lynn, Evan A

2006-11-01

The C-shaped root canal system and treatment implications were first described by Cooke and Cox in 1979. C-shaped canals are most frequently found in mandibular second molars, but they can occur in any mandibular molar, and they have been reported in maxillary molars as well. C-shaped mandibular molars are characterized by a C-shaped groove that connects one or more root canals. This groove can occur anywhere along the root canal system, making it difficult to diagnose and treat. A C-shaped root canal system may appear completely normal at the level of the pulp chamber but can begin to manifest itself in the middle or apical one-third. Furthermore, C-shaped canals are challenging if not impossible to predict radiographically. C-shaped canals in mandibular second molars are found most frequently in the Chinese population, with reports showing up to a 31.5% incidence, as compared to an approximate 7% incidence in the general population. This case report demonstrates an incidence of a C-shaped canal that was unable to be detected radiographically and which contained three separate root canals that communicated in the apical one-third of the root canal system. Canal orifices were located approximately 2 mm below the level of the CEJ, which is in agreement with a recent micro-computed tomography study of C-shaped mandibular molars that found 98% of all C-shaped molars studied had orifices located 1 mm to 3 mm below the CEJ. The CT study also found that all C-shaped canals contained fused roots and confirmed previous findings that the C-shape configuration varies greatly throughout the length of the canal.

Root canal volume change and transportation by Vortex Blue, ProTaper Next, and ProTaper Universal in curved root canals

PubMed Central

2018-01-01

Objectives The aim of this study was to compare root canal volume change and canal transportation by Vortex Blue (VB; Dentsply Tulsa Dental Specialties), ProTaper Next (PTN; Dentsply Maillefer), and ProTaper Universal (PTU; Dentsply Maillefer) nickel-titanium rotary files in curved root canals. Materials and Methods Thirty canals with 20°–45° of curvature from extracted human molars were used. Root canal instrumentation was performed with VB, PTN, and PTU files up to #30.06, X3, and F3, respectively. Changes in root canal volume before and after the instrumentation, and the amount and direction of canal transportation at 1, 3, and 5 mm from the root apex were measured by using micro-computed tomography. Data of canal volume change were statistically analyzed using one-way analysis of variance and Tukey test, while data of amount and direction of transportation were analyzed using Kruskal-Wallis and Mann-Whitney U test. Results There were no significant differences among 3 groups in terms of canal volume change (p > 0.05). For the amount of transportation, PTN showed significantly less transportation than PTU at 3 mm level (p = 0.005). VB files showed no significant difference in canal transportation at all 3 levels with either PTN or PTU files. Also, VB files showed unique inward transportation tendency in the apical area. Conclusions Other than PTN produced less amount of transportation than PTU at 3 mm level, all 3 file systems showed similar level of canal volume change and transportation, and VB file system could prepare the curved canals without significant shaping errors. PMID:29487834

Craniopharyngeal canal and its spectrum of pathology.

PubMed

Abele, T A; Salzman, K L; Harnsberger, H R; Glastonbury, C M

2014-04-01

The craniopharyngeal canal is a rare, well-corticated defect through the midline of the sphenoid bone from the sellar floor to the anterosuperior nasopharyngeal roof. We reviewed a series of craniopharyngeal canals to determine a system of classification that might better our understanding of this entity, highlight the range of associated pathologic conditions, and optimize patient treatment. Available MR imaging, CT, and clinical data (from 1989-2013) of 29 patients (10 female, 15 male, 4 unknown; median age, 4 years; age range, 1 day-65 years) with craniopharyngeal canals were retrospectively examined. Qualitative assessment included orthotopic or ectopic adenohypophysis and the presence of a tumor and/or cephalocele. The midpoint anteroposterior diameter was measured. Clinical and imaging data were evaluated for pituitary dysfunction and accompanying anomalies. Craniopharyngeal canals were qualitatively separated into 3 types: incidental canals (type 1); canals with ectopic adenohypophysis (type 2); and canals containing cephaloceles (type 3A), tumors (type 3B), or both (type 3C), including pituitary adenoma, craniopharyngioma, dermoid, teratoma, and glioma. Quantitative evaluation showed a significant difference (P < .0001) in the anteroposterior diameters of type 1 canals (median, 0.8; range, 0.7-1.1 mm), type 2 canals (median, 3.9, range, 3.5-4.4 mm), and type 3 canals (median, 9.0; range, 5.9-31.0 mm) imparting small, medium, and large descriptors. Canals with cephaloceles all contained an ectopic adenohypophysis. The craniopharyngeal canals were associated with pituitary dysfunction (6/29) and congenital anomalies (8/29). Accurate diagnosis and classification of craniopharyngeal canals are valuable to characterize lesions requiring surgery, identify patients with potential pituitary dysfunction, and avoid iatrogenic hypopituitarism or CSF leak during surgical resection of nasopharyngeal masses.

[Scanning electron microscopy investigation of canal cleaning after canal preparation with nickel titanium files].

PubMed

Brkanić, Tatjana; Ivana, Stojsin; Vukoje, Karolina; Zivković, Slavoljub

2010-01-01

Root canal preparation is the most important phase of endodontic procedure and it consists of adequate canal space cleaning and shaping. In recent years, rotary instruments and techniques have gained importance because of the great efficacy, speed and safety of the preparation procedure. The aim of this research was to investigate the influence of different NiTi files on the canal wall cleaning quality, residual dentine debris and smear layer. The research was conducted on extracted human teeth in vitro conditions. Teeth were divided in 7 main groups depending on the kind of instruments used for root canal preparation: ProTaper, GT, ProFile, K-3, FlexMaster, hand ProTaper and hand GT. Root canal preparation was accomplished by crown-down technique. Prepared samples were assessed on scanning electron microscopy JEOL, JSM-6460 LV. The evaluation of dentine debris was done with 500x magnification, and the evaluation of smear layer with 1,000 times magnification. Quantitive assessment of dentine debris and smear layer was done according to the criteria of Hulsmann. The least amount of debris and smear layer has been found in canals shaped with ProFile instruments, and the largest amount in canals shaped with FlexMaster instruments. Canal cleaning efficacy of hand GTand ProTaperfiles has been similar to cleaning efficacy of rotary NiTi files. Statistic analysis has shown a significant difference in amount of dentine debris and smear layer on the canal walls between sample groups. shaped with different instruments. Completely clean canals have not been found in any tested group of instruments. The largest amount of debris and smear layer has been found in the apical third of all canals. The design and the type of endodontic instruments influence the efficacy of the canal cleaning.

Micro-Computed Tomography Analysis of the Root Canal Morphology of Palatal Roots of Maxillary First Molars.

PubMed

Marceliano-Alves, Marília; Alves, Flávio Rodrigues Ferreira; Mendes, Daniel de Melo; Provenzano, José Claudio

2016-02-01

A thorough knowledge of root canal anatomy is critical for successful root canal treatments. This study evaluated the internal anatomy of the palatal roots of maxillary first molars with micro-computed tomography (microCT). The palatal roots of extracted maxillary first molars (n = 169) were scanned with microCT to determine several anatomic parameters, including main canal classification, lateral canal occurrence and location, degree of curvature, main foramen position, apical constriction presence, diameters 1 and 2 mm from the apex and 1 mm from the foramen, minor dentin thickness in those regions, canal volume, surface area, and convexity. All canals were classified as Vertucci type I. The cross sections were oval in 61% of the canals. Lateral canals were found in 25% of the samples. The main foramen did not coincide with the root apex in 95% of the cases. Only 8% of the canals were classified as straight. Apical constriction was identified in 38% of the roots. The minor and major canal diameters and minor dentin thickness were decreased near the apex. The minor dentin thickness 1 mm from the foramen was 0.82 mm. The palatal canals exhibited a volume of 6.91 mm(3) and surface area of 55.31 mm(2) and were rod-shaped. The root canals of the palatal roots were classified as type I. However, some factors need to be considered during the treatment of these roots, including the frequent ocurrence of moderate/severe curvatures, oval-shaped cross-sections, and lateral canals, noncoincidence of the apical foramen with the root apex, and absence of apical constriction in most cases. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The Kra Canal: An Analysis of a Foreign Policy Alternative for the United States Navy in the Indian Ocean

DTIC Science & Technology

1975-03-01

construction and operation of the canal. The minimal advantages offered by the canal over the existing passages through the Malay Peninsula-Indonesian...was analyzed with respect to the advantages and costs that would result from U.S. participa- tion in the construction and operation of the canal. The...Present Status of the Canal -------------- 28 3. Motivating Factors for the Canal ..........- 31 4. Construction ----------------------------- 34 5

Dorello's Canal for Laymen: A Lego-Like Presentation.

PubMed

Ezer, Haim; Banerjee, Anirban Deep; Thakur, Jai Deep; Nanda, Anil

2012-06-01

Objective Dorello's canal was first described by Gruber in 1859, and later by Dorello. Vail also described the anatomy of Dorello's canal. In the preceding century, Dorello's canal was clinically important, in understanding sixth nerve palsy and nowadays it is mostly important for skull base surgery. The understanding of the three dimensional anatomy, of this canal is very difficult to understand, and there is no simple explanation for its anatomy and its relationship with adjacent structures. We present a simple, Lego-like, presentation of Dorello's canal, in a stepwise manner. Materials and Methods Dorello's canal was dissected in five formalin-fixed cadaver specimens (10 sides). The craniotomy was performed, while preserving the neural and vascular structures associated with the canal. A 3D model was created, to explain the canal's anatomy. Results Using the petrous pyramid, the sixth nerve, the cavernous sinus, the trigeminal ganglion, the petorclival ligament and the posterior clinoid, the three-dimensional structure of Dorello's canal was defined. This simple representation aids in understanding the three dimensional relationship of Dorello's canal to its neighboring structures. Conclusion Dorello's canal with its three dimensional structure and relationship to its neighboring anatomical structures could be reconstructed using a few anatomical building blocks. This method simplifies the understanding of this complex anatomical structure, and could be used for teaching purposes for aspiring neurosurgeons, and anatomy students.

Dorello's Canal for Laymen: A Lego-Like Presentation

PubMed Central

Ezer, Haim; Banerjee, Anirban Deep; Thakur, Jai Deep; Nanda, Anil

2012-01-01

Objective Dorello's canal was first described by Gruber in 1859, and later by Dorello. Vail also described the anatomy of Dorello's canal. In the preceding century, Dorello's canal was clinically important, in understanding sixth nerve palsy and nowadays it is mostly important for skull base surgery. The understanding of the three dimensional anatomy, of this canal is very difficult to understand, and there is no simple explanation for its anatomy and its relationship with adjacent structures. We present a simple, Lego-like, presentation of Dorello's canal, in a stepwise manner. Materials and Methods Dorello's canal was dissected in five formalin-fixed cadaver specimens (10 sides). The craniotomy was performed, while preserving the neural and vascular structures associated with the canal. A 3D model was created, to explain the canal's anatomy. Results Using the petrous pyramid, the sixth nerve, the cavernous sinus, the trigeminal ganglion, the petorclival ligament and the posterior clinoid, the three-dimensional structure of Dorello's canal was defined. This simple representation aids in understanding the three dimensional relationship of Dorello's canal to its neighboring structures. Conclusion Dorello's canal with its three dimensional structure and relationship to its neighboring anatomical structures could be reconstructed using a few anatomical building blocks. This method simplifies the understanding of this complex anatomical structure, and could be used for teaching purposes for aspiring neurosurgeons, and anatomy students. PMID:23730547

ROUTING DEMAND CHANGES TO USERS ON THE WM LATERAL CANAL WITH SACMAN

USDA-ARS?s Scientific Manuscript database

Most canals have either long travel times or insufficient in-canal storage to operate on-demand. Thus, most flow changes must be routed through the canal. Volume compensation has been proposed as a method for easily applying feedforward control to irrigation canals. SacMan (Software for Automated Ca...

2. View looking northeast; Dundee Canal headgates and guardlock in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. View looking northeast; Dundee Canal headgates and guardlock in foreground, Dundee Dam and Passaic River in background - Dundee Canal Industrial Historic District, Beginning at George Street in Passaic & extending north along Dundee Canal approximately 1.2 miles to Canal headgates opposite East Clifton Avenue in Clifton, Passaic, Passaic County, NJ

ACHP | News

Science.gov Websites

Search skip specific nav links Home arrow News arrow March 7, 2014 C&O Canal Trust, C&O Canal along the 184.5-mile Chesapeake & Ohio (C&O) Canal, received the Advisory Council on Historic . The Canal Quarters program was created and operates through a partnership with the C&O Canal

Inverse solution of ear-canal area function from reflectance

PubMed Central

Rasetshwane, Daniel M.; Neely, Stephen T.

2011-01-01

A number of acoustical applications require the transformation of acoustical quantities, such as impedance and pressure that are measured at the entrance of the ear canal, to quantities at the eardrum. This transformation often requires knowledge of the shape of the ear canal. Previous attempts to measure ear-canal area functions were either invasive, non-reproducible, or could only measure the area function up to a point mid-way along the canal. A method to determine the area function of the ear canal from measurements of acoustic impedance at the entrance of the ear canal is described. The method is based on a solution to the inverse problem in which measurements of impedance are used to calculate reflectance, which is then used to determine the area function of the canal. The mean ear-canal area function determined using this method is similar to mean ear-canal area functions measured by other researchers using different techniques. The advantage of the proposed method over previous methods is that it is non- invasive, fast, and reproducible. PMID:22225043

Influence of operator experience on canal preparation time when using the rotary Ni-Ti ProFile system in simulated curved canals.

PubMed

Mesgouez, C; Rilliard, F; Matossian, L; Nassiri, K; Mandel, E

2003-03-01

The aim of this study was to determine the influence of operator experience on the time needed for canal preparation when using a rotary nickel-titanium (Ni-Ti) system. A total of 100 simulated curved canals in resin blocks were used. Four operators prepared a total of 25 canals each. The operators included practitioners with prior experience of the preparation technique, and practitioners with no experience. The working length for each instrument was precisely predetermined. All canals were instrumented with rotary Ni-Ti ProFile Variable Taper Series 29 engine-driven instruments using a high-torque handpiece (Maillefer, Ballaigues, Switzerland). The time taken to prepare each canal was recorded. Significant differences between the operators were analysed using the Student's t-test and the Kruskall-Wallis and Dunn nonparametric tests. Comparison of canal preparation times demonstrated a statistically significant difference between the four operators (P < 0.001). In the inexperienced group, a significant linear regression between canal number and preparation time occurred. Time required for canal preparation was inversely related to operator experience.

Characterization of sediment transport upstream and downstream from Lake Emory on the Little Tennessee River near Franklin, North Carolina, 2014–15

USGS Publications Warehouse

Huffman, Brad A.; Hazell, William F.; Oblinger, Carolyn J.

2017-09-06

Federal, State, and local agencies and organizations have expressed concerns regarding the detrimental effects of excessive sediment transport on aquatic resources and endangered species populations in the upper Little Tennessee River and some of its tributaries. In addition, the storage volume of Lake Emory, which is necessary for flood control and power generation, has been depleted by sediment deposition. To help address these concerns, a 2-year study was conducted in the upper Little Tennessee River Basin to characterize the ambient suspended-sediment concentrations and suspended-sediment loads upstream and downstream from Lake Emory in Franklin, North Carolina. The study was conducted by the U.S. Geological Survey in cooperation with Duke Energy. Suspended-sediment samples were collected periodically, and time series of stage and turbidity data were measured from December 2013 to January 2016 upstream and downstream from Lake Emory. The stage data were used to compute time-series streamflow. Suspended-sediment samples, along with time-series streamflow and turbidity data, were used to develop regression models that were used to estimate time-series suspended-sediment concentrations for the 2014 and 2015 calendar years. These concentrations, along with streamflow data, were used to compute suspended-sediment loads. Selected suspended-sediment samples were collected for analysis of particle-size distribution, with emphasis on high-flow events. Bed-load samples were also collected upstream from Lake Emory.The estimated annual suspended-sediment loads (yields) for the upstream site for the 2014 and 2015 calendar years were 27,000 short tons (92 short tons per square mile) and 63,300 short tons (215 short tons per square mile), respectively. The annual suspended-sediment loads (yields) for the downstream site for 2014 and 2015 were 24,200 short tons (75 short tons per square mile) and 94,300 short tons (292 short tons per square mile), respectively. Overall, the suspended-sediment load at the downstream site was about 28,300 short tons greater than the upstream site over the study period.As expected, high-flow events (the top 5 percent of daily mean flows) accounted for the majority of the sediment load; 80 percent at the upstream site and 90 percent at the downstream site. A similar relation between turbidity (the top 5 percent of daily mean turbidity) and high loads was also noted. In general, when instantaneous streamflows at the upstream site exceeded 5,000 cubic feet per second, increased daily loads were computed at the downstream site. During low to moderate flows, estimated suspended-sediment loads were lower at the downstream site when compared to the upstream site, which suggests that sediment deposition may be occurring in the intervening reach during those conditions. During the high-flow events, the estimated suspended-sediment loads were higher at the downstream site; however, it is impossible to say with certainty whether the increase in loading was due to scouring of lake sediment, contributions from the additional source area, model error, or a combination of one or more of these factors. The computed loads for a one-week period (December 24–31, 2015), during which the two largest high-flow events of the study period occurred, were approximately 52 percent of the 2015 annual sediment load (36 percent of 2-year load) at the upstream site and approximately 72 percent of the 2015 annual sediment load (57 percent of 2-year load) at the downstream site. Six bedload samples were collected during three events; two high-flow events and one base-flow event. The contribution of bedload to the total sediment load was determined to be insignificant for sampled flows. In general, streamflows for long-term streamgages in the study area were below normal for the majority of the study period; however, flows during the last 3 months of the study period were above normal, including the extreme events during the last week of the study period.

A comparative evaluation of the increase in root canal surface area and canal transportation in curved root canals by three rotary systems: A cone-beam computed tomographic study

PubMed Central

Prasanthi, Nalam NVD; Rambabu, Tanikonda; Sajjan, Girija S; Varma, K Madhu; Satish, R Kalyan; Padmaja, M

2016-01-01

Aim: The aim of this study was to measure the increase in root canal surface area and canal transportation after biomechanical preparation at 1, 3, and 5 mm short of the apex with three different rotary systems in both continuous rotary and reciprocating rotary motions. Materials and Methods: Sixty freshly extracted human mandibular molars with mesial root canal curvatures between 20° and 30° were included in the study. Teeth were randomly distributed into three groups (n = 20). Biomechanical preparations were done in all the mesial canals. In Group 1, instrumentation was done with ProTaper universal rotary files, Group 2, with K3XF rotary files, and Group 3, with LSX rotary files. Each group was further subdivided into subgroups A and B (n = 10) where instrumentation was done by continuous rotary and reciprocating rotary techniques, respectively. Increase in root canal surface area and canal transportation was measured using the preoperative and postoperative cone-beam computed tomography scans. Statistical Analysis: The data were analyzed by one-way ANOVA followed by Tukey pairwise multiple comparison tests. Results: Increase in root canal surface area was significantly more (P < 0.05) in ProTaper and K3XF groups when compared to LSX group. Canal transportation was significantly more (P < 0.05) in ProTaper group when compared to K3XF and LSX groups. There was no significant difference (P > 0.05) in increase of root canal surface area and canal transportation between continuous rotary and reciprocating rotary techniques for ProTaper Universal, K3XF and LSX groups. Conclusion: LSX rotary system showed minimal increase of root canal surface area and minimal canal transportation when compared to ProTaper and K3XF rotary systems. PMID:27656062

Levels of pesticides residues in the White Nile water in the Sudan.

PubMed

Nesser, Gibreel A A; Abdelbagi, Azhari O; Hammad, Ahmed Mohammed Ali; Tagelseed, Mirghani; Laing, Mark D

2016-06-01

Twenty-two commonly used pesticides were monitored during autumn, winter, and summer of 2004-2005 in 27 water samples from three sites along the White Nile in Sudan (former Sudan). Sites were selected to reflect pesticides gathered from drainage canals in central Sudan and from upstream sources. Collected samples were extracted and subjected to gas chromatographic analysis. Pesticides levels were measured in nanograms per liter. Pesticides residues were detected in 96 % of the samples with a total residue burden of 4132.6 ng L(-1), and an overall mean concentration and range of 50.99 and not detected-1570 ng L(-1), respectively. Ororganochlorines were the most frequently detected contaminants, which were found in 70 % of the samples, causing a total burden of 2852.8 ng L(-1), followed by pyrethroids 15 % of the samples, with a total burden of 926.5 ng L(-1). The tested herbicides were detected in ˂4 % of the samples with a total burden of 353.3 ng L(-1), while organophosphorus levels were below the detection limit. The most frequent contaminants were the following: heptachlor and its epoxide (52 % of samples), followed by DDTs (dichlorodiphenyltrichloroethanes) (DDT and DDE, in 19 % of the samples), cypermethrin and fenvalerate (in 11 % of the samples), and pendimethalin (in <4 % of the samples). Residues of hexachlorocyclohexane (HCH) isomers (α, β, γ and δ), endosulfan (α and β), p, p-DDD, λ cyhalothrin, deltamethrin, and oxyfluorfen were not detected in the analyzed samples. Generally, levels were least in autumn, and followed by summer and winter. Sources of contamination might include agricultural lands in central Sudan and upstream sources. Both recent and old contaminations were indicated.

Canal preparation with nickel-titanium or stainless steel instruments without the risk of instrument fracture: preliminary observations.

PubMed

Yared, Ghassan

2015-02-01

This report introduces a novel technique that allows a safe and predictable canal negotiation, creation of a glide path and canal preparation with reciprocating nickel-titanium or stainless steel engine-driven instruments in canals where the use of rotary and the newly developed reciprocating instruments is contraindicated. In this novel technique, the instruments are used in reciprocating motion with very small angles. Hand files are not used regardless of the complexity of the canal anatomy. It also allows achieving predictable results in canal negotiation and glide path creation in challenging canals without the risk of instrument fracture.

Endodontic management of a mandibular first molar with six root canal systems.

PubMed

Jain, Dilip; Reddy, Smitha; Venigalla, Bhuvan Shome; Kamishetty, Shekhar

2015-01-01

Internal anatomy of pulp is complex. The first mandibular molars typically have two roots, one mesial with two root canals and another distal root, which contains one or two canals. A 20-year-old female patient reported with intermittent pain and incomplete root canal treatment in left lower back region since 1-week. Refined access cavity revealed initially two canals in mesial and two canals in the distal root. With operating microscope and cone beam computerized tomography, two additional canals (L-mesio-buccal and B-mesio-lingual) were identified in mesial root. One-year follow-up showed patient was asymptomatic and complete healing of periapical radiolucency.

Canal preparation with nickel-titanium or stainless steel instruments without the risk of instrument fracture: preliminary observations

PubMed Central

2015-01-01

This report introduces a novel technique that allows a safe and predictable canal negotiation, creation of a glide path and canal preparation with reciprocating nickel-titanium or stainless steel engine-driven instruments in canals where the use of rotary and the newly developed reciprocating instruments is contraindicated. In this novel technique, the instruments are used in reciprocating motion with very small angles. Hand files are not used regardless of the complexity of the canal anatomy. It also allows achieving predictable results in canal negotiation and glide path creation in challenging canals without the risk of instrument fracture. PMID:25671218

Streamflow and water quality of the Grand Calumet River, Lake County, Indiana, and Cook County, Illinois, October 1984

USGS Publications Warehouse

Crawford, Charles G.; Wangsness, David J.

1987-01-01

A diel (24-hour) water-quality survey was done to investigate the sources of dry-weather waste inputs attributable to other than permitted point-source effluent and to evaluate the waste-load assimilative capacity of the Grand Calumet River, Lake County, Indiana, and Cook County, Illinois, in October 1984. Flow in the Grand Calumet River consists almost entirely of municipal and industrial effluents which comprised more than 90% of the 500 cu ft/sec flow observed at the confluence of the East Branch Grand Calumet River and the Indiana Harbor Ship Canal during the study. At the time of the study, virtually all of the flow in the West Branch Grand Calumet River was municipal effluent. Diel variations in streamflow of as much as 300 cu ft/sec were observed in the East Branch near the ship canal. The diel variation diminished at the upstream sampling sites in the East Branch. In the West Branch, the diel variation in flow was quite drastic; complete reversals of flow were observed at sampling stations near the ship canal. Average dissolved-oxygen concentrations at stations in the East Branch ranged from 5.7 to 8.2 mg/L and at stations in the West Branch from 0.8 to 6.6 mg/L. Concentrations of dissolved solids, suspended solids, biochemical-oxygen demand, ammonia, nitrite, nitrate, and phosphorus were substantially higher in the West Branch than in the East Branch. In the East Branch, only the Indiana Stream Pollution Control Board water-quality standards for total phosphorus and phenol were exceeded. In the West Branch, water-quality standards for total ammonia, chloride, cyanide, dissolved solids, fluoride, total phosphorus, mercury, and phenol were exceeded and dissolved oxygen was less than the minimum allowable. Three areas of significant differences between cumulative effluent and instream chemical-mass discharges were identified in the East Branch and one in the West Branch. The presence of unidentified waste inputs in the East Branch were indicated by differences in the chemical-mass discharges at three sites. Elevated suspended solids, biochemical-oxygen demand, and ammonia chemical-mass discharges at Columbia Avenue indicated the presence of a source of what may have been untreated sewage to the West Branch during the survey. (Author 's abstract)

Model simulations of potential contribution of the proposed Huangpu Gate to flood control in the Lake Taihu basin of China

NASA Astrophysics Data System (ADS)

Zhang, Hanghui; Liu, Shuguang; Ye, Jianchun; Yeh, Pat J.-F.

2017-10-01

The Lake Taihu basin (36 895 km2), one of the most developed regions in China located in the hinterland of the Yangtze River Delta, has experienced increasing flood risk. The largest flood in history occurred in 1999 with a return period estimate of 200 years, considerably larger than the current capacity of the flood defense with a design return period of 50 years. Due to its flat saucer-like terrain, the capacity of the flood control system in this basin depends on flood control infrastructures and peripheral tidal conditions. The Huangpu River, an important river of the basin connecting Lake Taihu upstream and Yangtze River estuaries downstream, drains two-fifths of the entire basin. Since the water level in the Huangpu River is significantly affected by the high tide conditions in estuaries, constructing an estuary gate is considered an effective solution for flood mitigation. The main objective of this paper is to assess the potential contributions of the proposed Huangpu Gate to the flood control capacity of the basin. To achieve this goal, five different scenarios of flooding conditions and the associated gate operations are considered by using numerical model simulations. Results of quantitative analyses show that the Huangpu Gate is effective for evacuating floodwaters. It can help to reduce both peak values and duration of high water levels in Lake Taihu to benefit surrounding areas along the Taipu Canal and the Huangpu River. The contribution of the gate to the flood control capacity is closely associated with its operation modes and duration. For the maximum potential contribution of the gate, the net outflow at the proposed site is increased by 52 %. The daily peak level is decreased by a maximum of 0.12 m in Lake Taihu, by maxima of 0.26-0.37 and 0.46-0.60 m in the Taipu Canal and the Huangpu River, respectively, and by 0.05-0.39 m in the surrounding areas depending on the local topography. It is concluded that the proposed Huangpu Gate can reduce flood risk in the Lake Taihu basin, especially in those low-lying surrounding areas along the Taipu Canal and the Huangpu River significantly, which is of great benefit to the flood management in the basin and the Yangtze River Delta.

Cone-beam computed tomography analysis of curved root canals after mechanical preparation with three nickel-titanium rotary instruments

PubMed Central

Elsherief, Samia M.; Zayet, Mohamed K.; Hamouda, Ibrahim M.

2013-01-01

Cone beam computed tomography is a 3-dimensional high resolution imaging method. The purpose of this study was to compare the effects of 3 different NiTi rotary instruments used to prepare curved root canals on the final shape of the curved canals and total amount of root canal transportation by using cone-beam computed tomography. A total of 81 mesial root canals from 42 extracted human mandibular molars, with a curvature ranging from 15 to 45 degrees, were selected. Canals were randomly divided into 3 groups of 27 each. After preparation with Protaper, Revo-S and Hero Shaper, the amount of transportation and centering ability that occurred were assessed by using cone beam computed tomography. Utilizing pre- and post-instrumentation radiographs, straightening of the canal curvatures was determined with a computer image analysis program. Canals were metrically assessed for changes (surface area, changes in curvature and transportation) during canal preparation by using software SimPlant; instrument failures were also recorded. Mean total widths and outer and inner width measurements were determined on each central canal path and differences were statistically analyzed. The results showed that all instruments maintained the original canal curvature well with no significant differences between the different files (P = 0.226). During preparation there was failure of only one file (the protaper group). In conclusion, under the conditions of this study, all instruments maintained the original canal curvature well and were safe to use. Areas of uninstrumented root canal wall were left in all regions using the various systems. PMID:23885273

An in vitro evaluation of the degree of pulp tissue dissolution through different root canal irrigation protocols.

PubMed

Amato, Massimo; Pantaleo, Giuseppe; Abtellatif, Dina; Blasi, Andrea; Gagliani, Massimo; Iandolo, Alfredo

2018-01-01

The aim of this study is to evaluate in vitro , using artificial lateral canals, the rate of dissolution of the pulp tissue through different protocols of canal irrigation. One hundred artificial canals provided with lateral canals have been used. Each lateral canal was filled with pulp tissue and calibrated to 0.002 mg. All canals were irrigated using five different protocols. Five groups have been used for the experiment: Group A, distilled water (control); Group B, preheated NaOCl; Group C, NaOCl heated inside the canal; Group D, NaOCl ultrasonically activated; and Group E, NaOCl heated inside the canal with ultrasonic activation. All samples were weighed through professional microbalance in three different phases: before insertion of the pulp tissue into the lateral canal, after insertion of the pulp tissue and, finally, after different protocols of irrigation. A statistical analysis with Kruskal-Wallis test and Mann-Whitney test was performed. The partial dissolution of the pulp tissue inside the artificial lateral canal occurs only using the protocol with NaOCl heated inside the canal with ultrasonic activation. Other irrigation protocols are not able to dissolve the pulp tissue. The main objective of endodontic therapy is the removal of damaged tissues and bacteria. Modern literature highlights that it is impossible to remove all the pulp tissues and bacteria from the whole endodontic space. Hence, to achieve excellence and get positive results in the short and long term, it is necessary to use techniques and technologies that may increase the degree of root canal detersion.

Analysis of Resin-Dentin Interface Morphology and Bond Strength Evaluation of Core Materials for One Stage Post-Endodontic Restorations

PubMed Central

Bitter, Kerstin; Gläser, Christin; Neumann, Konrad; Blunck, Uwe; Frankenberger, Roland

2014-01-01

Purpose Restoration of endodontically treated teeth using fiber posts in a one-stage procedure gains more popularity and aims to create a secondary monoblock. Data of detailed analyses of so called “post-and-core-systems” with respect to morphological characteristics of the resin-dentin interface in combination with bond strength measurements of fiber posts luted with these materials are scarce. The present study aimed to analyze four different post-and-core-systems with two different adhesive approaches (self-etch and etch-and-rinse). Materials and Methods Human anterior teeth (n = 80) were endodontically treated and post space preparations and post placement were performed using the following systems: Rebilda Post/Rebilda DC/Futurabond DC (Voco) (RB), Luxapost/Luxacore Z/Luxabond Prebond and Luxabond A+B (DMG) (LC), X Post/Core X Flow/XP Bond and Self Cure Activator (Dentsply DeTrey) (CX), FRC Postec/MultiCore Flow/AdheSE DC (Ivoclar Vivadent) (MC). Adhesive systems and core materials of 10 specimens per group were labeled using fluorescent dyes and resin-dentin interfaces were analyzed using Confocal Laser Scanning Microscopy (CLSM). Bond strengths were evaluated using a push-out test. Data were analyzed using repeated measurement ANOVA and following post-hoc test. Results CLSM analyses revealed significant differences between groups with respect to the factors hybrid layer thickness (p<0.0005) and number of resin tags (p = 0.02; ANOVA). Bond strength was significantly affected by core material (p = 0.001), location inside the root canal (p<0.0005) and incorporation of fluorescent dyes (p = 0.036; ANOVA). CX [7.7 (4.4) MPa] demonstrated significantly lower bond strength compared to LC [14.2 (8.7) MPa] and RB [13.3 (3.7) MPa] (p<0.05; Tukey HSD) but did not differ significantly from MC [11.5 (3.5) MPa]. Conclusion It can be concluded that bond strengths inside the root canal were not affected by the adhesive approach of the post-and-core-system. All systems demonstrated homogenous hybrid layer formation and penetration into the dentinal tubules in spite of the complicating conditions for adhesion inside the root canal. PMID:24586248

Acetylcholinesterase inhibition and gill lesions in Rasbora caverii, an indigenous fish inhabiting rice field associated waterbodies in Sri Lanka.

PubMed

Wijeyaratne, W M D N; Pathiratne, Asoka

2006-10-01

The present study was aimed at applying condition factor (CF), brain acetylcholinesterase (AChE) and gill histology as biomarkers for detecting possible exposure/effect induced by pesticides in fish residing rice field associated waterbodies in Sri Lanka. Biomarkers of an indigenous fish, Rasbora caverii collected from five sampling sites including canals near rice fields, a river and a reservoir (the reference site) were evaluated at four sampling stages covering pesticide application periods during rice cultivation season in 2004. Results indicated that CF of the fish did not show significant alterations regardless of the sampling sites or sampling stages. Site specific differences in AChE activities of the fish were not evident either prior to application of pesticides or at 7 days after Paraquat application to the rice fields. Two days after the application of a mixture of Fenthion and Phenthoate to the rice fields, AChE activity of the fish collected from canals near rice fields was significantly depressed (65-75%) compared to the fish in the reference site. The activities remain depressed to 50-56% even at 65 days after the insecticides application. Laboratory studies showed that prior exposure of R. caverii to Paraquat (2 microg l(-1), 7 days) enhanced the extent of inhibition of brain AChE activity induced by Fenthion (3 microg l(-1)) or a mixture of Fenthion (3 microg l(-1)) and Phenthoate (5 microg l(-1)). Gills of fish collected from canals near rice fields exhibited abnormal multiple divisions at the tips of some secondary lamellae in addition to hyperplasia, hypertrophy and club shaped deformities. Results indicate that application of pesticides in rice culture could manifest a threat to native fish populations residing rice field associated waterbodies. The response of brain AChE and histological changes in the gills of R. caverii allowed differentiating sampling sites after insecticide applications to the rice fields. Hence, R. caverii may be considered as a surrogate species in ecotoxicological risk evaluation of agrochemicals in the region.

Sacramento Metropolitan Area, California

DTIC Science & Technology

1992-02-01

restriction would apply to virtually all of West Sacramento. Future conditions in the bypass areas are expected to remain essentially the same. During...frequency, the stage-frequency curve in the study area essentially becomes flat because of the large storage volume behind upstream levee breaches. This curve...and 400-year flood plains are also essentially the same (15 to 16 feet) because of the following: 1) the flood volume for each event is sufficient to

Context view, looking southwest along the WelltonMohawk Canal. The wasteway ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Context view, looking southwest along the Wellton-Mohawk Canal. The wasteway is marked by the white posts on either side of the access road. The pipe across the canal safely carries storm runoff over the canal and is not part of Wasteway No. 1 - Wellton-Mohawk Irrigation System, Wasteway No. 1, Wellton-Mohawk Canal, North side of Wellton-Mohawk Canal, bounded by Gila River to North & the Union Pacific Railroad & Gila Mountains to south, Wellton, Yuma County, AZ

[A mandibular second molar with three mesial roots: report of one case].

PubMed

Zhang, Ping

2010-02-01

A case of unusual root canal morphology was presented to demonstrate anatomic variations in mandibular second molars. This case report presented the endodontic therapy of a mandibular second molar with three canals in the mesial root. A mesial middle canal was found between the mesiobuccal and mesiolingual canals. This report indicated the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise to fail.

Comparison Of Pre-Operative Curvature With Postoperative Curvature In Root Canals Treated With K-3 Rotary Systems.

PubMed

Nagi, Sana Ehsen; Khan, Farhan Raza

2017-01-01

With root canal treatment, the organic debris and micro-organisms from pulp space is removed and an ideal canal preparation is achieved that is conducive of hermetic obturation. The purpose of this study was to correlate the pre-operative canal curvature with the postoperative curvature in human extracted teeth prepared with K-3 rotary systems. The root canal preparation was carried out on extracted human molars and premolars using K-3 endodontic rotary files. A pre and post-operative image of the teeth using digital radiograph were taken in order to compare pre and post-operative canal curvature. The images were saved in an images retrieval system (Gendex software, USA). Change in the canal curvature was measured using the software measuring tool (Vixwin software, USA). Student paired t-test and Pearson correlation test was applied at 0.05 level of significance. There is a statistically significant difference between pre-operative and post-operative canal curvature (p-value <0.001) and a strong positive correlation (91% correlation) between pre-operative and post-operative canal curvature in teeth prepared with the K-3 rotary files. A significant difference between pre and post instrumentation curvature was found. Degree of canal curvature was not correlated with time taken for canal preparation.

Your baby in the birth canal

MedlinePlus

... lie; Fetal attitude; Fetal descent; Fetal station; Cardinal movements; Labor-birth canal; Delivery-birth canal ... are used to describe your baby's position and movement through the birth canal. FETAL STATION Fetal station ...

Water Environment Evolution along the China Grand Canal

NASA Astrophysics Data System (ADS)

Mao, F.; Wu, Y. X.; Yang, B. F.; Li, X. J.

2014-03-01

The China Grand Canal is one of the earliest canals in the world, having lasted for nearly 3000 years. Even its section canals have a rich history, such as the North-South Grand Canal that was established during the Sui Dynasty, whereas the Beijing-Hangzhou Canal was excavated during the Yuan Dynasty and the east line of the South-to-North Water Diversion. As one of the longest in the world, the China Grand Canal's total length is over 3500 kilometers. This length includes the navigable, unnavigable, and underground sections. Making the best use of situations and according to local conditions, the Chinese people harmoniously constructed the Beijing-Hangzhou Canal with nature. Tens of millions of workers took nearly 3000 years to complete the great shipping system. Navigable sections still exist for up to 900 kilometers and the volume of freight traffic is approximately 300 million tons. The canal remains the main logistical channel of the North-to-South Coal Transportation, South-to-North Water Diversion, and resources circulation. To date, China is promoting the success of heritage application. Part of these efforts is the declaration of the China Grand Canal as a World Cultural Heritage by 2014. In addition, the east route of the South-to-North Water Transfer project is planned to be navigable by 2016. The ancient Beijing-Hangzhou Grand Canal will usher in the new ecological civilization and cultural revival along the canal. This paper presents technical methods of water environment evolution research on the river system, river, and water quality along the Beijing-Hangzhou Canal through the integration of historical literature and modern remote sensing image data. The study carried out water environment investigation and analysis along the Beijing-Hangzhou canal by using ETM, SPOT image data, and GPS measurement data. Spatial and temporal evolution characteristics and regulations of the Beijing-Hangzhou Grand Canal regional water environment in the span of 3000 years were obtained. As a key national cultural relic, candidate of the world cultural heritage, and route of the South-to-North Water Diversion, the China Great Canal is a worthy subject of a study. Results presented in this paper therefore have high realistic significance.

158. Photocopy of transit book (taken from Twin Falls Canal ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

158. Photocopy of transit book (taken from Twin Falls Canal Company Transit Book #404T, Page 3, #46, Division One). START OF MAIN CANAL SURVEY, TWIN FALLS COUNTY, MILNER, IDAHO. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

177. Photocopy of Photograph, Twin Falls Canal Company, Bisbee Photo, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

177. Photocopy of Photograph, Twin Falls Canal Company, Bisbee Photo, September, 1912. Photographer unknown. COTTONWOOD FLUME, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; SOUTH VIEW FROM UPPER SIDE. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

46 CFR 69.7 - Vessels transiting the Panama and Suez Canals.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Vessels transiting the Panama and Suez Canals. 69.7... MEASUREMENT OF VESSELS MEASUREMENT OF VESSELS General § 69.7 Vessels transiting the Panama and Suez Canals. (a... Canal must be measured and certificated under the Arab Republic of Egypt Suez Canal Authority Rules of...

7. 'FLOW IN CANAL NO. 1, A JOINTLY USED CANAL, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. 'FLOW IN CANAL NO. 1, A JOINTLY USED CANAL, ON MAY 22 WHEN 210 SECOND FEET OF WATER WAS FLOWING. THIS WAS LATER INCREASED TO 240 SECOND FEET FOR A NUMBER OF DAYS TO SATISFY THE DEMANDS OF THE DRY GULCH COMPANY.' 1925 - Irrigation Canals in the Uinta Basin, Duchesne, Duchesne County, UT

Silicone infusion tubing instead of Hunter rods for two-stage zone 2 flexor tendon reconstruction in a resource-limited surgical environment.

PubMed

Kibadi, K; Moutet, F

2017-10-01

The authors describe their experience using silicone infusion tubing in place of Hunter rods for two-stage zone 2 flexor tendon reconstruction in a resource-limited surgical environment. This case report features a 47-year-old, right-handed man who had no active PIP and DIP joint flexion in four fingers of the right hand 5 months after an injury. During the first repair stage, the A2 and A4 pulleys were reconstructed using an extensor retinaculum graft. An infusion tube was inserted instead of Hunter rods. During the second stage, formation of a digital neo-canal around the infusion tubing was observed. The infusion tubing was removed and replaced with a palmaris longus tendon graft according to the conventional technique. Physiotherapy and rehabilitation followed surgery. At 6 months, very significant progress had been made with complete recovery of PIP and DIP flexion in the four fingers. Copyright © 2017 SFCM. Published by Elsevier Masson SAS. All rights reserved.

[Shaping ability of multi-taper nickel-titanium files in simulated resin curved root canal].

PubMed

Luo, Hong-Xia; Huang, Ding-Ming; Jia, Liu-He; Luo, Shi-Gao; Gao, Xiao-Jie; Tan, Hong; Zhou, Xue-Dong

2006-08-01

To compare the shaping ability of ISO standard stainless steel K files and multi-taper ProTaper nickel-titanium files in simulated resin curved root canals. METHODS Thirty simulated resin root canals were randomly divided into three groups and prepared by stainless steel K files, hand ProTaper, rotary ProTaper, respectively. The amount of material removed from inner and outer wall and canal width after canal preparation was measured, while the canal curvature before and after canal preparation and canals aberrations were recorded. The stainless steel K files removed more material than hand ProTaper and rotary ProTaper at the outer side of apex and inner side of curvature (P < 0.05). The mean degree of straightening in stainless steel K files group was significantly bigger than in ProTaper group (P < 0.05). The canals prepared by ProTaper had no evident aberration. The shaping ability of ProTaper is better than stainless steel K files.

Accumulation of 1-deoxynojirimycin in silkworm, Bombyx mori L.

PubMed

Yin, Hao; Shi, Xin-qin; Sun, Bo; Ye, Jing-jing; Duan, Zu-an; Zhou, Xiao-ling; Cui, Wei-zheng; Wu, Xiao-feng

2010-04-01

1-deoxynojirimycin (1-DNJ) contents in the silkworm, Bombyx mori, at different developmental stages and tissues were investigated by using reverse-phase high-performance liquid chromatography. The 1-DNJ contents of silkworm larvae change significantly with their developmental stages. The male larvae showed higher accumulation efficiency of 1-DNJ than the females and also a significant variation was observed among the silkworm strains. The present results show that tissue distribution of 1-DNJ was significantly higher in blood, digestive juice, and alimentary canal, but no 1-DNJ was observed in the silkgland. Moreover, 1-DNJ was not found in silkworms fed with artificial diet that does not contain mulberry leaf powder. This proves that silkworms obtain 1-DNJ from mulberry leaves; they could not synthesize 1-DNJ by themselves. The accumulation and excretion of 1-DNJ change periodically during the larval stage. There was no 1-DNJ in the newly-hatched larvae and 1-DNJ was mainly accumulated during the early and middle stages of every instar, while excreted at later stages of larval development. Further, it is possible to extract 1-DNJ from the larval feces and it is optimal to develop the 1-DNJ related products for diabetic auxiliary therapy.

3. August, 1971. VIEW ALONG CANAL SHOWING BORDER PATH AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. August, 1971. VIEW ALONG CANAL SHOWING BORDER PATH AND BRIDGE FOR INSPECTION - ABOUT ONE MILE FROM CANAL HEAD. - Hurricane Irrigation Canal, State Route 15 Vicinity, Hurricane, Washington County, UT

Mandibular first premolar with four canals.

PubMed

Du, Yi; Lee, Angeline H C; Zhang, Chengfei

2013-02-01

A case of endodontic treatment of a mandibular first premolar exhibiting a total of four distinct root canals and four apical foramina is described. This occurrence in mandibular first premolar has rarely been reported in the endodontic literature. Endodontic treatment that considers the anatomic variation of root canal morphology is important to ensure a favorable healing outcome, and its identification could be enhanced by careful examination using a dental operating microscope. Obturation of root canals using a warm vertical compaction technique with a highly-radiopaque root canal sealer, such as AH Plus, after careful ultrasonic activated irrigation with ethylenediaminetetraacetic acid might allow the flow of sealer into the narrowed but unprepared part of the canal. This offers valuable adjuncts for the successful negotiation of calcified main canals, thereby facilitating optimum chemo-mechanical debridement of the root canal system. © 2013 Blackwell Publishing Asia Pty Ltd.

A mandibular third molar with three mesial roots: a case report.

PubMed

Plotino, Gianluca

2008-02-01

Although its most common configuration is 2 roots and 3 root canals, mandibular molars might have many different combinations. A case of unusual root canal morphology is presented to demonstrate anatomic variations in mandibular molars. Endodontic therapy was performed in a mandibular third molar with 3 separate mesial roots. The appearance of the pulp chamber floor revealed 4 separate canal orifices. Radiographically the 4 root canals ended in their own distinct foramen. Many reports deal with 3 orifices or 3 independent canals in the mesial root, but none described 3 mesial canals in 3 separate mesial roots, indicating a rare anatomic configuration. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure.

[Comparative study of root canal morphology of mandibular first premolar by micro-CT and radio visio graphy].

PubMed

Li, Xiangjie; Liu, Na; Liu, Rui; Dong, Zhengmou; Liu, Luchuan; Deng, Manjing

2012-02-01

To compare the consistency of root canal configuration types of mandibular first premolar by using micro-CT and radio visio graphy (RVG). One hundred extracted mandibular first premolars with complete dental root and apex which received no endodontic treatment were randomly selected. Each tooth was radiographed with RVG through a buccolingual and mesiodistal direction, and then scanned with micro-CT and reconstructed. The classifications of the root canal types according to Vertucci's type with the two methods were compared. The canal patterns were classified as type I (67%), type III (3%), type V (18%), type VII (2%), additional type (10%) with micro-CT and canal patterns as type I (71%), type III (2%), type V (23%), type VII (1%), additional type (3%) with RVG. 63% of teeth showed one canal in both micro-CT and RVG. Only 25% of teeth were diagnosed as complex canal by the same canal type in both micro-CT and RVG. The Kappa value between micro-CT and RVG was 0.541 which suggested that the two kinds of methods had intermediate consistency. 82.8% of the premolars with root groove had two or more than two canals. Although RVG can basically reflect the root canal system type of the mandibular first premolars in vitro, it offers poor accuracy images to complex root canals. Micro-CT three-dimensional images could clearly and precisely display the root canal system morphology of the mandibular first pre-molars in vitro.

Root Canal Anatomy and Morphology of Mandibular First Molars in a Selected Iranian Population: An In Vitro Study

PubMed Central

Mohammadzadeh Akhlaghi, Nahid; Khalilak, Zohreh; Vatanpour, Mehdi; Mohammadi, Saman; Pirmoradi, Sakineh; Fazlyab, Mahta; Safavi, Kamran

2017-01-01

Introduction: The aim of this study was to evaluate root canal anatomy of mandibular first molars (MFM) in a selected Iranian Population using clearing technique. Methods and Materials: A total of 150 extracted MFMs were cleared. The root canal morphology (including the root numbers and root length) and the anatomy of the root canal system (including is the number and type of canals based on Vertucci’s classification, canal curvature according to Schneider's method and the presence of isthmus) was evaluated using the buccolingual and mesiodistal parallel x-rays and stereomicroscope. The data were analyzed using the chi-square test. Results: Two and three roots were present in 96.7% and 33% of the teeth, respectively (P=0.0001). All the teeth (100%) had two canals in the mesial root, while 61.3% of the samples had one distal root canal (P=0.006). The root canal configuration in the mesial canal included type IV (55.3%) and type II (41.3%) (P=0.0001). In doubled-canalled distal roots, 68.8% and 24.3% were type II and type IV, respectively (P=0.0001). Isthmii were observed in 44.6% of mesial and 27.3% of distal roots (P=0.0001). Conclusion: The notable prevalence of type IV configuration in both roots of mandibular first molars, presence of isthmus and root curvature, necessitates the careful negotiation and cleaning of all accessible canal spaces. PMID:28179932

Root canal irrigants

PubMed Central

Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

2010-01-01

Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were ‘root canal irrigants’ and ‘endodontic irrigants.’ The reference lists of each article were manually checked for additional articles of relevance. PMID:21217955

Northeastern Florida Bay estuarine creek data, water years 1996-2000

USGS Publications Warehouse

Hittle, Clinton D.; Zucker, Mark A.

2004-01-01

From October 1995 to September 2000 (water years 1996-2000), continuous 15-minute stage, water velocity, salinity, and water temperature data were collected at seven estuarine creeks that flow into northeastern Florida Bay. These creeks include West Highway Creek, Stillwater Creek, Trout Creek, Mud Creek, Taylor River, Upstream Taylor River, and McCormick Creek. Discharge was computed at 15-minute intervals using mean water velocity and the cross-sectional area of the channel. Fifteen-minute unit values are presented for comparison of the quantity, quality, timing, and distribution of flows through the creeks. Revised discharge estimation formulas are presented for three noninstrumented sites (East Highway Creek, Oregon Creek and Stillwater Creek) that utilize an improved West Highway discharge rating. Stillwater Creek and Upstream Taylor River were originally noninstrumented sites; both were fully instrumented in 1999. Discharge rating equations are presented for these sites and were developed using a simple linear regression.

Psychiatric disorders: The psychiatrist's contribution to sport.

PubMed

Currie, Alan; Johnston, Allan

2016-12-01

Athletes experience a range of mental health problems with at least an equivalent prevalence to the general population. This chapter explores the psychiatrist's role in sport, along a pathway of mental healthcare from 'upstream' prevention, screening, and early detection of mental stress to 'downstream' assessment, treatment, rehabilitation, and recovery from mental illness. At each stage on this pathway the psychiatrist has a broad spectrum of bio-psycho-social strategies to employ in clinical practice. Upstream, the importance of psychological resilience is described along with the concept of mental 'pre-habilitation' (a term usually associated with the prevention of physical injury). Alongside these preventative measures, early detection is improved by education, increased awareness, and by the use of effective mental health screening measures. Further downstream ready access to psychiatric expertise and good collaboration between the psychiatrist and the world of sport improve access to treatment, delivery of that treatment, rehabilitation, and return to sport during recovery.

A stele-enriched gene regulatory network in the Arabidopsis root

PubMed Central

Brady, Siobhan M; Zhang, Lifang; Megraw, Molly; Martinez, Natalia J; Jiang, Eric; Yi, Charles S; Liu, Weilin; Zeng, Anna; Taylor-Teeples, Mallorie; Kim, Dahae; Ahnert, Sebastian; Ohler, Uwe; Ware, Doreen; Walhout, Albertha J M; Benfey, Philip N

2011-01-01

Tightly controlled gene expression is a hallmark of multicellular development and is accomplished by transcription factors (TFs) and microRNAs (miRNAs). Although many studies have focused on identifying downstream targets of these molecules, less is known about the factors that regulate their differential expression. We used data from high spatial resolution gene expression experiments and yeast one-hybrid (Y1H) and two-hybrid (Y2H) assays to delineate a subset of interactions occurring within a gene regulatory network (GRN) that determines tissue-specific TF and miRNA expression in plants. We find that upstream TFs are expressed in more diverse cell types than their targets and that promoters that are bound by a relatively large number of TFs correspond to key developmental regulators. The regulatory consequence of many TFs for their target was experimentally determined using genetic analysis. Remarkably, molecular phenotypes were identified for 65% of the TFs, but morphological phenotypes were associated with only 16%. This indicates that the GRN is robust, and that gene expression changes may be canalized or buffered. PMID:21245844

Magnitude and frequency of flooding on the Myakka River, Southwest Florida

USGS Publications Warehouse

Hammett, K.M.; Turner, J.F.; Murphy, W.R.

1978-01-01

Increasing numbers of urban and agricultural developments are being located on waterfront property in the Myakka River flood plain in southwest Florida. Under natural conditions, a large depression, Tatum Sawgrass, was available as a flood storage area in the upper Myakka River basin. Construction of dikes across the lower part of Tatum Sawgrass has restricted use of the depression for temporary storage of Myakka River flood water overflow, and has resulted in increased flood-peak discharges and flood heights in downstream reaches of the Myakka River. The difference between natural and diked condition flood-peak discharges and flood heights is presented to illustrate the effects of the dikes. Flood-peak discharges, water-surface elevations and flood profiles also are provided for diked conditions. Analytical procedures used to evaluate diking effects are described in detail. The study reach includes Myakka River main stem upstream from U.S. Highway 41, near Myakka Shores in Sarasota County, to State Road 70 near Myakka City in Manatee County (including Tatum Sawgrass and Clay Gully), and Blackburn Canal from Venice By-Way to Myakka River. (Woodard-USGS)

Simulation of 3-D viscous compressible flow in multistage turbomachinery by finite element methods

NASA Astrophysics Data System (ADS)

Sleiman, Mohamad

1999-11-01

The flow in a multistage turbomachinery blade row is compressible, viscous, and unsteady. Complex flow features such as boundary layers, wake migration from upstream blade rows, shocks, tip leakage jets, and vortices interact together as the flow convects through the stages. These interactions contribute significantly to the aerodynamic losses of the system and degrade the performance of the machine. The unsteadiness also leads to blade vibration and a shortening of its life. It is therefore difficult to optimize the design of a blade row, whether aerodynamically or structurally, in isolation, without accounting for the effects of the upstream and downstream rows. The effects of axial spacing, blade count, clocking (relative position of follow-up rotors with respect to wakes shed by upstream ones), and levels of unsteadiness may have a significance on performance and durability. In this Thesis, finite element formulations for the simulation of multistage turbomachinery are presented in terms of the Reynolds-averaged Navier-Stokes equations for three-dimensional steady or unsteady, viscous, compressible, turbulent flows. Three methodologies are presented and compared. First, a steady multistage analysis using a a-mixing- plane model has been implemented and has been validated against engine data. For axial machines, it has been found that the mixing plane simulation methods match very well the experimental data. However, the results for a centrifugal stage, consisting of an impeller followed by a vane diffuser of equal pitch, show flagrant inconsistency with engine performance data, indicating that the mixing plane method has been found to be inappropriate for centrifugal machines. Following these findings, a more complete unsteady multistage model has been devised for a configuration with equal number of rotor and stator blades (equal pitches). Non-matching grids are used at the rotor-stator interface and an implicit interpolation procedure devised to ensure continuity of fluxes across. This permits the rotor and stator equations to be solved in a fully- coupled manner, allowing larger time steps in attaining a time-periodic solution. This equal pitch approach has been validated on the complex geometry of a centrifugal stage. Finally, for a stage configuration with unequal pitches, the time-inclined method, developed by Giles (1991) for 2-D viscous compressible flow, has been extended to 3-D and formulated in terms of the physical solution vector U, rather than Q, a non-physical one. The method has been evaluated for unsteady flow through a rotor blade passage of the power turbine of a turboprop.

150. Photocopy of drawing (taken from Twin Falls Canal Company ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

150. Photocopy of drawing (taken from Twin Falls Canal Company Surveyor's Book #363, Page 42, entitled, 'Diversion Tunnels', located in Twin Falls Canal Company office, Twin Falls, Idaho). PLAN OF DIVERSION TUNNELS, MILNER DAM. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

180. Photocopy of Photograph, Twin Falls Canal Company. E. Pettygro, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

180. Photocopy of Photograph, Twin Falls Canal Company. E. Pettygro, Photographer, date unknown. BLASTING TWIN FALLS CANAL, TWIN FALLS COUNTY; BLASTING COTTONWOOD AREA TO REPLACE FLUME BY RUNNING HIGH LINE THROUGH SOLID ROCK. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

Canal switch and re-entry phenomenon in benign paroxysmal positional vertigo: difference between immediate and delayed occurrence.

PubMed

Dispenza, F; DE Stefano, A; Costantino, C; Rando, D; Giglione, M; Stagno, R; Bennici, E

2015-04-01

This prospective study was designed to evaluate the differences between immediate and delayed canal re-entry of otoliths after therapeutic manoeuvres in patients with benign paroxysmal positional vertigo (BPPV). A total of 196 patients with BPPV were visited and 127 matched our inclusion criteria. The mean age was 54.74 years. The horizontal semicircular canal (HSC) was involved in 30 cases and the posterior semicircular canal (PSC) in 97 patients. Patients with hearing loss in the ear affected by BPPV have a more recurrent form, compared to those with normal hearing. An immediate canal re-entry was recorded in 3 patients with HSC BPPV, all with geotropic nystagmus. In 7 patients with PSC BPPV, the immediate canal re-entry was detected and the delayed form was noted in 5 patients. The patients with the delayed canal re-entry underwent more than 2 previous manoeuvres. The canal re-entry was not related to the manoeuvre performed. The timing of the Dix-Hallpike test to verify the resolution of the BPPV had a significant role in immediate canal re-entry. A recurrence in the follow-up at least one month after treatment was recorded in 20 patients and was more frequent in patients that had canal re-entry. The canal re-entry or canal switch is a clinical entity that should be kept in mind of the neurotologist when approaching BPPV patients. It is important to distinguish it from recurrence when delayed and from manoeuvre failure when immediate. The timing of manoeuvre performing, in particular the final verification test after therapeutic sessions, is important to prevent the immediate reflux of particles into canals.

Interrelationships in the Variability of Root Canal Anatomy among the Permanent Teeth: A Full-Mouth Approach by Cone-Beam CT

PubMed Central

Peters, Ove A.; Maury, Elisabeth; Telmon, Norbert; Georgelin-Gurgel, Marie; Maret, Delphine

2016-01-01

Objectives In endodontic practice, clinicians should be aware of possible root canal anatomic variations. The aim of this study was to assess using CBCT acquisitions regarding whether one root canal anatomy of a tooth is associated with a specific anatomy of another tooth. Methods A total of 106 CBCT acquisitions were obtained using a CBCT scanner with 200μm voxel size. Numbers of roots and canals of the entire dentition were described. Bivariate analyses and logistic regressions were conducted to explore root canal anatomy on one tooth according to age, gender, jaw, side and the others teeth. Multiple correspondence analysis (MCA) was performed to correlate the different numbers of canals profiles. Results A total of 2424 teeth were analyzed. Independently from the other variables, the presence of an additional root canal on a mandibular incisor increases the risk of having an additional root canal on a mandibular premolar (OR [95%] 3.7 [1.0;13.2]). The mandibular molar variability increases in women compared to men (OR [95%] 0.4 [0.1; 0.9]). MCA showed correspondence between 2-canals maxillary incisor and canines and 5-canals maxillary molars, and some correlation between additional canal on maxillary and mandibular premolars. Conclusions Although CBCT examinations are conducted in the first intention of making a diagnosis or prognostic evaluation, medium FOV acquisitions could be used as an initial database thus furnishing preliminary evaluations and information. In endodontic practice, clinicians should be aware of possible root canal anatomic variations. The visualization of all canals is considered essential in endodontic therapy. The use of multi-correspondence analysis for statistics in endodontic research is a new approach as a prognostic tool. PMID:27764246

Lock No. 1 St. Lucie Canal. Upper gate structure, masonry ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Lock No. 1- St. Lucie Canal. Upper gate structure, masonry plan- masonry elevations. - St. Lucie Canal, St. Lucie Lock No. 1, St. Lucie, Cross State Canal, Okeechobee Intracoastal Waterway, Stuart, Martin County, FL

2. BLACK RIVER CANAL SUPPLY FROM END OF MAIN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. BLACK RIVER CANAL - SUPPLY FROM END OF MAIN CANAL TO BLACK RIVER. VIEW TO SOUTHWEST - Carlsbad Irrigation District, Black River Canal, 15 miles Southeast of Carlsbad near Malaga, Carlsbad, Eddy County, NM

Dundee Canal Industrial Historic District, Beginning at George Street in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Dundee Canal Industrial Historic District, Beginning at George Street in Passaic & extending north along Dundee Canal approximately 1.2 miles to Canal headgates opposite East Clifton Avenue in Clifton, Passaic, Passaic County, NJ

A randomized, blinded study of canal wall up versus canal wall down mastoidectomy determining the differences in viewing middle ear anatomy and pathology.

PubMed

Hulka, G F; McElveen, J T

1998-09-01

Canal wall down and intact canal wall tympanomastoidectomy represent two surgical approaches to middle ear pathology. The authors hypothesize that there is a difference in the ability to view structures in the middle ear between these two methods. Depending on the individual, many surgeons have used the two different techniques of intact canal wall and canal wall down tympanomastoidectomy for approaching the middle ear. However, opinions conflict as to which approach provides the best visualization of different locations in the middle ear. This study prospectively evaluated temporal bones to determine the differences in visualizing structures of the middle ear using these two approaches. Twelve temporal bones underwent a standardized canal wall down tympanomastoidectomy using a reversible canal wall down technique. All bones were viewed in two dissections: intact canal wall and canal wall down preparations. Four points previously had been marked on each temporal bone in randomly assigned colors. These points include the sinus tympani, posterior crus of stapes, lateral epitympanum, and the Eustachian tube orifice. An observer blinded to the purpose of the study, color, and number of locations recorded the color and location of marks observed within the temporal bones. Randomized bones of two separate settings were viewed such that each bone was viewed in both the canal wall down and the intact canal wall preparations. A significant difference was noted in the ability to observe middle ear pathology between the intact canal wall versus canal wall down tympanomastoidectomy, with the latter showing superiority (p < 0.001). Of the four subsites, the sinus tympani, posterior crus of stapes, and lateral epitympanum were observed more frequently with the canal wall down. There was no significant difference in the ability to observe the Eustachian tube orifice between the two techniques. Statistical analysis shows good reproducibility and randomization of this study. The canal wall down tympanomastoidectomy allowed for superior viewing of the three locations, sinus tympanic, posterior crus of stapes, and lateral at the tympanum, as they were marked in the study. This study shows the potential for improved visualization via the canal wall down tympanomastoidectomy. A significant amount of literature written by individuals and otology group practices is available retrospectively comparing the advantages and disadvantages of intact canal wall versus canal wall down mastoidectomy procedures for approaching middle ear pathology. In the interest of objectively evaluating the differences between these two approaches, we have studied temporal bones in a prospective randomized, blinded study comparing the two. Twelve bones were used and observed twice, once in each of 2 sessions. All bones were viewed in two dissections: intact canal wall and canal wall down mastoidectomy. Four points were marked on each temporal bone in three different colors applied in a randomized order to eliminate observer expectation. The four points marked include sinus tympani, posterior crus of the stapes footplate, lateral epitympanum, and Eustachian tube orifice. Both intact canal wall and canal wall down bones were provided randomly to the observer at each viewing session. Before the observer was allowed to see the dissections, those requiring replacement of the canal for the first session of the study had this done in a method using native posterior bony canal. Temporal bones were presented to an expert otologist in a randomized fashion with each temporal bone being placed in a temporal bone bowl holder and specialized framework, allowing for rotation and repositioning approximating the experience in an operating room setting. For each temporal bone, the observer filled in a questionnaire describing his or her observations by denoting both location and color of marks observed. (ABSTRACT TRUNCATED)

Root and Root Canal Morphology of Human Third Molar Teeth.

PubMed

Mohammadi, Zahed; Jafarzadeh, Hamid; Shalavi, Sousan; Bandi, Shilpa; Patil, Shankargouda

2015-04-01

Successful root canal treatment depends on having comprehensive information regarding the root(s)/canal(s) anatomy. Dentists may have some complication in treatment of third molars because the difficulty in their access, their aberrant occlusal anatomy and different patterns of eruption. The aim of this review was to review and address the number of roots and root canals in third molars, prevalence of confluent canals in third molars, C-shaped canals, dilaceration and fusion in third molars, autotransplantation of third molars and endodontic treatment strategies for third molars.

The role of rice fields, fish ponds and water canals for transmission of fish-borne zoonotic trematodes in aquaculture ponds in Nam Dinh Province, Vietnam.

PubMed

Madsen, Henry; Dung, Bui Thi; The, Dang Tat; Viet, Nguyen Khue; Dalsgaard, Anders; Van, Phan Thi

2015-12-08

Fish-borne zoonotic trematodes (FZT), such as Clonorchis sinensis, Opistorchis viverini (Opisthorchiidae) and intestinal trematodes of the family Heterophyidae, constitute a public health hazard in Vietnam and infections with these trematodes has been linked to consumption of raw or undercooked fish from aquaculture. The FZT transmission pathways, however, are more complicated than just the presence of intermediate snail hosts in aquaculture ponds as ponds may exchange water with surrounding habitats such as rice fields and irrigation canals and thereby these surrounding habitats may be a source of snails and cercariae and contribute to FZT infection in cultured fish. This is a longitudinal descriptive study on selected farms (n = 30) in Nam Dinh Province which is endemic for FZT. At each farm, we sampled one pond, a small irrigation canal used to supply the pond with water, and a nearby rice field. At each of these three sites, we estimated the density of the FZT intermediate snail hosts and determined their trematode infection status. Comparative analysis was performed for the prevalence and density of FZT infections in fish and snails. Species of the Thiaridae, and most notably Melanoides tuberculata, the most important host species for FZT belonging to the Heterophyidae, were particularly abundant in ponds and small canals, i.e. M. tuberculata was found in 27 ponds and 13 small canals. Bithynia fuchsiana, a potential host for both Heterophyidae and Opisthorchiidae, was rarely found in fish ponds but common in rice fields. A total of 12 types of cercariae were found in the snails and pleurolophocercous cercariae, primarily FZT, constituted about 40 % of all cercarial infections. The fish species cultured were mainly carp species and Haplorchis pumilio was the dominating trematode species infecting fish. Clonorchis spp. were not recorded in any of the ponds. FZT transmission to fish was intense during the summer period (May-June to November) but less intense during the winter months (December-January) partly because cercarial emergence ceases due to the low temperature. Our findings highlight the complexity of FZT transmission within aquaculture farm settings and suggest that efforts to control these infections must take a holistic approach using interventions against all stages of the transmission cycle.

Influence of irrigation regimens on the adherence of Enterococcus faecalis to root canal dentin.

PubMed

Kishen, Anil; Sum, Chee-Peng; Mathew, Shibi; Lim, Chwee-Teck

2008-07-01

Enterococcus faecalis is frequently associated with post-treatment endodontic infections. Because adherence of bacteria to a substrate is the earliest stage in biofilm formation, eliciting the factors that links adherence of this bacterium to dentin would help in understanding its association with treatment-failed root canals. This investigation aimed to study the effects of endodontic irrigants on the adherence of E. faecalis to dentin. The bacteria adherence assay was conducted by using fluorescence microscopy, and the adhesion force was measured by using atomic force microscopy. There were significant increases in adherence and adhesion force after irrigation of dentin with ethylenediaminetetraacetic acid (EDTA), whereas sodium hypochlorite (NaOCl) reduced it. With the use of chlorhexidine (CHX), the force of adhesion increased, but the adherence assay showed a reduction in the number of adhering bacteria. The irrigation regimen of EDTA, NaOCl, and CHX resulted in the least number of adhering E. faecalis cells. This study highlighted that chemicals that alter the physicochemical properties of dentin will influence the nature of adherence, adhesion force, and subsequent biofilm formation of E. faecalis to dentin.

Installation Restoration Program. Phase 2. Confirmation/Quantification. Stage 2. Volume 1. Luke Air Force Base, Arizona.

DTIC Science & Technology

1988-06-15

equipped with an oil/water separator. Separated oil would be collected for reuse or proper disposal, and water would be piped to the Sewage Treatment...1940’s. The STP is located on Glendale Avenue, approximately 2 miles east of the Main Base, and adjacent to the Agua Fria River as shown in Figure 1-7...flow. The effluent from the STP is discharged into a canal that flows into lagoons in the dry Agua Fria River bed. The treated efflu- ent is routinely

Endodontic photodynamic therapy ex vivo

PubMed Central

Ng, Raymond; Singh, Fiza; Papamanou, Despoina A.; Song, Xiaoqing; Patel, Chitrang; Holewa, Colleen; Patel, Niraj; Klepac-Ceraj, Vanja; Fontana, Carla R.; Kent, Ralph; Pagonis, Tom C.; Stashenko, Philip P.; Soukos, Nikolaos S.

2010-01-01

Objective To evaluate the anti-microbial effects of photodynamic therapy (PDT) on infected human teeth ex vivo. Materials and Methods Fifty-two freshly extracted teeth with pulpal necrosis and associated periradicular radiolucencies were obtained from 34 subjects. Twenty-six teeth with 49 canals received chemomechanical debridement (CMD) with 6% NaOCl and twenty-six teeth with 52 canals received CMD plus PDT. For PDT, root canal systems were incubated with methylene blue (MB) at concentration of 50 µg/ml for 5 minutes followed by exposure to red light at 665 nm with an energy fluence of 30 J/cm2. The contents of root canals were sampled by flushing the canals at baseline and following CMD alone or CMD+PDT and were serially diluted and cultured on blood agar. Survival fractions were calculated by counting colony-forming units (CFU). Partial characterization of root canal species at baseline and following CMD alone or CMD+PDT was performed using DNA probes to a panel of 39 endodontic species in the checkerboard assay. Results The Mantel-Haenszel chi-square test for treatment effects demonstrated the better performance of CMD+PDT over CMD (P=0.026). CMD+PDT significantly reduced the frequency of positive canals relative to CMD alone (P=0.0003). Following CMD+PDT, 45 of 52 canals (86.5%) had no CFU as compared to 24 of 49 canals (49%) treated with CMD (canal flush samples). The CFU reductions were similar when teeth or canals were treated as independent entities. Post-treatment detection levels for all species were markedly lower for canals treated by CMD+PDT than were for those treated by CMD alone. Bacterial species within dentinal tubules were detected in 17/22 (77.3%) and 15/29 (51.7%) of canals in the CMD and CMD+PDT group, respectively (P= 0.034). Conclusion Data indicate that PDT significantly reduces residual bacteria within the root canal system, and that PDT, if further enhanced by technical improvements, holds substantial promise as an adjunct to CMD. PMID:21238805

A study on FlexMaster : a Ni-Ti rotary engine driven system for root canal preparation.

PubMed

Alam, M S; Bashar, A K; Begumr, J A; Kinoshita, J I

2006-07-01

In the present study, the effectiveness of recently introduced rotary Nickel Titanium FlexMaster engine driven system was evaluated for cleaning and shaping of root canals in extracted human teeth and compared with that done by the Nickel Titanium Flexofile hand instruments. A total of 40 root canals from 36 extracted mandibular and maxillary teeth with curvature ranging between 20 and 30 degree were divided into two groups, consisting 20 canals in each. FlexMaster instrumentation was done in 20 canals, using crown-down technique and manual filing with Flexofile was done in other 20 canals, using conventional and step-back techniques. 5.25% sodium hypochlorite (NaOCl) solution and 17% ethelene di-amine tetra-acetic acid (EDTA) were used alternatively for irrigation after canal preparation by each instrument size. Time needed for canal preparation of individual canal was recorded. A procedural error such as instrument breakage was also noted. After preparation, all the roots were cut longitudinally by using diamond burs in turbine handpiece and examined under scanning electron microscope. Apical region was quantified for debris and smear layer based on a 5-score numerical evaluation scale. The data established for scoring the debris and smear layer and preparation time of individual canal were analyzed statistically using the Mann-Whitney U test. Completely cleaned root canals were not found with any of the two instruments and none of the instruments maintained the original canal uniformity and regular dentine surface. Because significantly less debris was found in the apical region using the manual filing technique (p< 0.05). Thus the flexmaster system was found to produce less cleaner root canal walls than manual technique. Only one FlexMaster finishing file sized 30 was separated in the apical region during preparation of 30 degree curved canal. The time taken by FlexMaster was significantly better (p< 0.01) than that of hand instruments.

Prevalence of Apical Periodontitis in Endodontically Treated Premolars and Molars with Untreated Canal: A Cone-beam Computed Tomography Study.

PubMed

Karabucak, Bekir; Bunes, Alf; Chehoud, Christel; Kohli, Meetu R; Setzer, Frank

2016-04-01

The purpose of this retrospective cohort study was to evaluate the incidence of missed canals in endodontically treated teeth in the Greater Philadelphia area patient population and to evaluate the effect of untreated canals on endodontic outcome. A total of 1397 cone-beam computed tomography (CBCT) volumes taken from January 2013 to July 2015 were investigated. Limited view CBCT images were taken with Kodak 9000 3D System field of view at voxel size, 76 μm or Morita Veraviewpocs 3D F40 field of view at voxel size, 125 μm. All root canal-treated premolars and molars were included in the study. Unfilled canals appearing from cementoenamel junction to apex including splitting from a main canal at coronal, mid, or apical third were defined as missed-untreated canal. A periapical lesion was diagnosed when disruption of the lamina dura was detected and the low density area associated with the radiographic apex was at least twice the width of the periodontal ligament space. The overall incidence of missed canals was 23.04%. The incidence of missed canals per tooth was highest in tooth #14 at 46.5% and tooth #3 at 41.3%. The incidence of missed canals was highest in the upper molars at 40.1% and lowest in the upper premolars at 9.5%. There was a significant difference in lesion prevalence when a canal was missed-untreated (P < .05). Teeth with a missed canal were 4.38 times more likely to be associated with a lesion. Limited field-of-view CBCT should be examined before any endodontic retreatment to identify missed canals. This knowledge would not only help clinicians to locate missed canals clinically but would also help in deciding the surgical approach. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Instrument separation analysis of multi-used ProTaper Universal rotary system during root canal therapy.

PubMed

Wu, Jintao; Lei, Gang; Yan, Ming; Yu, Yan; Yu, Jinhua; Zhang, Guangdong

2011-06-01

The purpose of this study was to identify the influential factors responsible for clinical instrument separation of reused ProTaper Universal rotary instruments (Dentsply Maillefer, Ballaigues, Switzerland). Six thousand one hundred fifty-four root canals in 2,654 teeth were prepared using ProTaper Universal files in endodontic clinics. Separation incidence was determined based on the number of treated teeth or canals. Data were collected including the size of fractured instrument, the length and location of a broken segment within the root canal, and the curvature of canal. The chi-square test and independent samples t test were used to determine the statistical significance. The overall instrument separation incidences were 2.6% according to the number of teeth and 1.1% according to the canal number, respectively. Separation incidences according to the number of teeth or canals were significantly higher (P < .05) in molars than those in premolars or anterior teeth. Because of its largest diameter, F3 file presented the highest separation incidence according to the number of teeth (1.0%) or canals (0.4%); 47.5% instrument separation of mandibular molars and 61.5% instrument separation of maxillary molars happened in the mesiobuccal canals. Moreover, 91.4% fragments were located in the apical third of root canals, and 54.2% instrument separation occurred in severely curved canals. There was a significant difference (P < .05) in the mean fracture length between shaping (2.42 ± 0.73 mm) and finishing files (3.32 ± 0.73 mm). Separation incidence according to the canal number is more reliable than that according to the number of teeth because of the variable canal number in different teeth. The tooth type, rotary file size, canal location, and anatomy were correlated with the instrument separation of reused ProTaper Universal files. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Regulation of drainage canals on the groundwater level in a typical coastal wetlands

NASA Astrophysics Data System (ADS)

Liu, Qiang; Mou, Xia; Cui, Baoshan; Ping, Fan

2017-12-01

Activities related to reclamation alter wetland hydrological regimes and inevitably cause changes to groundwater level, which can result in the ecological degradation of coastal wetlands. Decreasing the groundwater level by the construction of drainage canals is an approach that has been widely used to control levels of root zone soil salinity as well as to protect freshwater wetlands or to expand agricultural land area in coastal wetlands. In this study, we assessed the influences of different drainage canal designs on the groundwater level using the Visual MODFLOW (VMOD) interface. We also provided an optimized drainage canal design suitable for the Yellow River Delta (YRD). Results showed that: (i) the groundwater level decreased in areas close to drainage canals, while only negligible effects were found on the groundwater level in areas with no drainage canals; (ii) the influence of drainage canals on the groundwater level decreased as distance increased; and (iii) a drainage canal network design of a depth of 5 m, with canal configuration of north-south direction and canal spacing of 1000 m was more effective in reducing the groundwater level in the study area. Our findings indicated that changes in groundwater level by the construction of drainage canals could help in our understanding of how groundwater influences freshwater wetlands and also aid in maintaining the integrity of coastal wetlands.

Quantitative three-dimensional analysis of root canal curvature in maxillary first molars using micro-computed tomography.

PubMed

Lee, Jong-Ki; Ha, Byung-Hyun; Choi, Jeong-Ho; Heo, Seok-Mo; Perinpanayagam, Hiran

2006-10-01

In endodontic therapy, access and instrumentation are strongly affected by root canal curvature. However, the few studies that have actually measured curvature are mostly from two-dimensional radiographs. The purpose of this study was to measure the three-dimensional (3D) canal curvature in maxillary first molars using micro-computed tomography (microCT) and mathematical modeling. Extracted maxillary first molars (46) were scanned by microCT (502 image slices/tooth, 1024 X 1024 pixels, voxel size of 19.5 x 19.5 x 39.0 microm) and their canals reconstructed by 3D modeling software. The intersection of major and minor axes in the canal space of each image slice were connected to create an imaginary central axis for each canal. The radius of curvature of the tangential circle was measured and inverted as a measure of curvature using custom-made mathematical modeling software. Root canal curvature was greatest in the apical third and least in the middle third for all canals. The greatest curvatures were in the mesiobuccal (MB) canal (0.76 +/- 0.48 mm(-1)) with abrupt curves, and the least curvatures were in the palatal (P) canal (0.38 +/- 0.34 mm(-1)) with a gradual curve. This study has measured the 3D curvature of root canals in maxillary first molars and reinforced the value of microCT with mathematical modeling.

Functional Implications of Ubiquitous Semicircular Canal Non-Orthogonality in Mammals

PubMed Central

Berlin, Jeri C.; Kirk, E. Christopher; Rowe, Timothy B.

2013-01-01

The ‘canonical model’ of semicircular canal orientation in mammals assumes that 1) the three ipsilateral canals of an inner ear exist in orthogonal planes (i.e., orthogonality), 2) corresponding left and right canal pairs have equivalent angles (i.e., angle symmetry), and 3) contralateral synergistic canals occupy parallel planes (i.e., coplanarity). However, descriptions of vestibular anatomy that quantify semicircular canal orientation in single species often diverge substantially from this model. Data for primates further suggest that semicircular canal orthogonality varies predictably with the angular head velocities encountered in locomotion. These observations raise the possibility that orthogonality, symmetry, and coplanarity are misleading descriptors of semicircular canal orientation in mammals, and that deviations from these norms could have significant functional consequences. Here we critically assess the canonical model of semicircular canal orientation using high-resolution X-ray computed tomography scans of 39 mammal species. We find that substantial deviations from orthogonality, angle symmetry, and coplanarity are the rule for the mammals in our comparative sample. Furthermore, the degree to which the semicircular canals of a given species deviate from orthogonality is negatively correlated with estimated vestibular sensitivity. We conclude that the available comparative morphometric data do not support the canonical model and that its overemphasis as a heuristic generalization obscures a large amount of functionally relevant variation in semicircular canal orientation between species. PMID:24260256

26. DETAIL OF HEADGATE HOIST MACHINERY, TWIN FALLS MAIN CANAL. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

26. DETAIL OF HEADGATE HOIST MACHINERY, TWIN FALLS MAIN CANAL. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

Endodontic management of radix paramolaris with six canals: a clinical case report.

PubMed

Acharya, N; Singh, A; Samant, P S; Gautam, V

2013-01-01

Endodontic therapy of mandibular molars is a challenging task due to its varied root canal morphology. A mandibular first molar with additional buccal root (Radix paramolaris) and additional distolingual root (Radix Entomolaris) is an example of its varied anatomy. A successful management of atypical root canal configurations is an important aspect in determining the success rate of root canal therapy. The detail knowledge of the root morphology and canal anatomy allows the clinician for accurate location of the extra roots and canals and accordingly the refinement of the access cavity for the stress free entry of complex anatomy. Hence, for a successful root canal therapy, clinician must be aware of the external and internal anatomic variations .The aim of this clinical case report is to present and describe the unusual presence of two separate mesial roots and six root canals in mandibular first molar, detected during routine endodontic therapy.

Development of a Rotating Rake Array for Boundary-Layer-Ingesting Fan-Stage Measurements

NASA Technical Reports Server (NTRS)

Wolter, John D.; Arend, David J.; Hirt, Stefanie M.; Gazzaniga, John A.

2017-01-01

The recent Boundary-Layer-Ingesting Inlet/Distortion Tolerant Fan wind tunnel experiment at NASA Glenn Research Center's 8- by 6-foot Supersonic Wind Tunnel (SWT) examined the performance of a novel inlet and fan stage that was designed to ingest the vehicle boundary layer in order to take advantage of a predicted overall propulsive efficiency benefit. A key piece of the experiment's instrumentation was a pair of rotating rake arrays located upstream and downstream of the fan stage. This paper examines the development of these rake arrays. Pre-test numerical solutions were sampled to determine placement and spacing for rake pressure and temperature probes. The effects of probe spacing and survey density on the repeatability of survey measurements was examined. These data were then used to estimate measurement uncertainty for the adiabatic efficiency.

Development of a Rotating Rake Array for Boundary-Layer-Ingesting Fan-Stage Measurements

NASA Technical Reports Server (NTRS)

Wolter, John D.; Arend, David J.; Hirt, Stefanie M.; Gazzaniga, John A.

2017-01-01

The recent Boundary-Layer-Ingesting Inlet/Distortion Tolerant Fan wind tunnel experiment at NASA Glenn Research Center's 8-foot by 6-foot supersonic wind tunnel examined the performance of a novel inlet and fan stage that was designed to ingest the vehicle boundary layer in order to take advantage of a predicted overall propulsive efficiency benefit. A key piece of the experiment's instrumentation was a pair of rotating rake arrays located upstream and downstream of the fan stage. This paper examines the development of these rake arrays. Pre-test numerical solutions were sampled to determine placement and spacing for rake pressure and temperature probes. The effects of probe spacing and survey density on the repeatability of survey measurements was examined. These data were then used to estimate measurement uncertainty for the adiabatic efficiency.

154. Photocopy of transit book (taken from Twin Falls Canal ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

154. Photocopy of transit book (taken from Twin Falls Canal Company Surveyor's Transit Book #405T, Page 2, #46 Division One). STATEMENT OF SIGHT-SETTING FOR 1903 SURVEY TO ALIGN SOUTH SIDE CANAL, TWIN FALLS COUNTY, MILNER, IDAHO. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

28. MAIN CANAL Photographic copy of historic photo, July ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

28. MAIN CANAL - Photographic copy of historic photo, July 18, 1906 (original print located at the Carlsbad Irrigation District offices, Carlsbad, New Mexico) J.J. Lubken, photographer 'LOOKING SOUTH FROM STATION 413, ON THE MAIN CANAL, SHOWING THE REMODLING SIC OF THE OLD PECOS VALLEY IRRIGATING CANAL' - Carlsbad Irrigation District, Main Canal, 4 miles North to 12 miles Southeast of Carlsbad, Carlsbad, Eddy County, NM

The effect of four different irrigation systems in the removal of a root canal sealer.

PubMed

Grischke, J; Müller-Heine, A; Hülsmann, M

2014-09-01

The aim of this study was to compare the efficiency of sonic, ultrasonic, and hydrodynamic devices in the removal of a root canal sealer from the surface and from simulated irregularities of root canals. Fifty-three root canals with two standardized grooves in the apical and coronal parts of longitudinally split roots were covered with AH Plus root canal sealer. Compared were the effects of (control) syringe irrigation, (1) CanalBrush, (2) passive ultrasonic irrigation, (3) EndoActivator, and (4) RinsEndo on the removal of the sealer. The specimens were divided into four groups (N = 12) and one control group (N = 5) via randomization. The amount of remaining sealer in the root canal irregularities was evaluated under a microscope using a 4-grade scoring system, whereas the remaining sealer on the root canal surface was evaluated with a 7-grade scoring system. Passive ultrasonic irrigation is more effective than the other tested irrigation systems or syringe irrigation in removing sealer from root canal walls (p < 0.01). None of the techniques had a significant effect on cleaning the lateral grooves. Within the limitations of this study protocol ultrasonic irrigation shows a superior effect on sealer removal from the root canal surface during endodontic retreatment. Cleaning of lateral grooves seems not to be possible with one of the techniques investigated. Incomplete removal of root canal sealer during re-treatment may cause treatment failure. Passive Ultrasonic irrigation seems to be the most effective system to remove sealer from a root canal.

Radiographic study of the mandibular retromolar canal: an anatomic structure with clinical importance.

PubMed

von Arx, Thomas; Hänni, Andrea; Sendi, Pedram; Buser, Daniel; Bornstein, Michael M

2011-12-01

The retromolar canal is an anatomic structure of the mandible with clinical importance. This canal branches off from the mandibular canal behind the third molar and travels to the retromolar foramen in the retromolar fossa. The retromolar canal might conduct accessory innervation to the mandibular molars or contain an aberrant buccal nerve. Patients referred for panoramic radiography were consecutively enrolled, provided a limited cone-beam computed tomography (CBCT) scan had also been taken in the area of interest. Radiographs were retrospectively screened for the presence of a retromolar canal, and linear measurements (distance to second molar, height, width) were taken. One hundred twenty-one sides in 100 patients were evaluated (100 unilateral and 21 bilateral cases). A total of 31 retromolar canals were identified with CBCT (25.6%). Only 7 of these canals were also seen on the corresponding panoramic radiographs. The existence of a retromolar canal was not statistically related to gender or side. With regard to the linear measurements, the mean distance from the retromolar canal to the second molar was 15.16 mm (±2.39 mm), the mean height of the canal was 11.34 mm (±2.36 mm), and the mean width was 0.99 mm (±0.31 mm). This radiographic study documents a frequency of 25% for the presence of a retromolar canal. The clinician is advised to preserve this anatomic variation when performing surgery in the retromolar area and to consider additional locoregional anesthesia in the case of failed mandibular block anesthesia. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Simulation of the effects of proposed tide gates on circulation, flushing, and water quality in residential canals, Cape Coral Florida

USGS Publications Warehouse

Goodwin, Carl R.

1991-01-01

Decades of dredging and filling of Florida's low-lying coastal wetlands have produced thousands of miles of residential tidal canals and adjacent waterfront property. Typically, these canals are poorly flushed, and over time, accumulated organic-rich bottom materials, contribute to an increasingly severe degraded water quality. One-dimensional hydrodynamic and constituent-transport models were applied to two dead-end canal systems to determine the effects of canal system interconnection using tide gates on water circulation and constituent flushing. The model simulates existing and possible future circulation and flushing conditions in about 29 miles of the approximately 130 miles of tidally influenced canals in Cape Coral, located on the central west coast of peninsular Florida. Model results indicate that tidal water-level differences between the two canal systems can be converted to kinetic energy, in the form of increased water circulation, but the use of one-way tide gate interconnections. Computations show that construction of from one to four tide gates will cause replacement of a volume of water equivalent to the total volume of canals in both systems in 15 to 9 days, respectively. Because some canals flush faster than others, 47 and 21 percent of the original canal water will remain in both systems 50 days after start of operation of one and four tide gates, respectively. Some of the effects that such increased flushing are expected to have include reduced density stratification and associated dissolved-oxygen depletion in canal bottom waters, increased localized reaeration, and more efficient discharge of stormwater runoff entering the canals.

Clinical, parasitological and immunological features of canal cleaners hyper-exposed to Schistosoma mansoni in the Sudan

PubMed Central

SATTI, M Z; SULAIMAN, S M; HOMEIDA, M M A; YOUNIS, S A; GHALIB, H W

1996-01-01

The present work was a longitudinal study on Schistosoma mansoni infection in occupationally hyperexposed canal cleaners in the Sudan and the influence of therapy on the parasitological and humoral immune parameters. Chronically infected canal cleaners (n = 28) were more resistant to reinfection (Fisher's exact test, P < 0.05) than newly recruited canal cleaners (n = 17). Chronically infected canal cleaners had a significantly higher degree of Symmers' fibrosis (χ2 = 19.1, P < 0.0001), significantly larger portal vein diameter (P < 0.05) and enlarged spleen (χ2 = 4.2, P < 0.05) than recently infected, newly recruited canal cleaners. ELISA was used to detect IgG, IgA and IgM in response to whole worm homogenate (WWH) and cercarial homogenate (CH). Chronically infected canal cleaners had significantly higher IgG to WWH antigen than newly recruited canal cleaners and normally exposed individuals (P < 0.05), while both chronically infected and newly recruited canal cleaners had higher IgG levels to CH antigen than normally exposed individuals (P < 0.05). The newly recruited canal cleaners had a significantly higher IgM level to CH antigen than chronically infected canal cleaners (P < 0.05). The IgG level to WWH antigen increased significantly after treatment in newly recruited canal cleaners and normally exposed individuals (P < 0.05). The IgA level to CH antigen increased significantly after treatment in the chronically infected group (P < 0.05). Comparison of the serological parameters between the different study groups with regards to infection and treatment is discussed. PMID:9099926

[Root canal treatment of mandibular second premolar tooth with taurodontism].

PubMed

Vujasković, Mirjana; Karadzić, Branislav; Miletić, Vesna

2008-01-01

Taurodontism is a morphoanatomical change in the shape of a tooth. An enlarged body of a tooth with smaller than usual roots is a characteristic feature. Internal tooth anatomy correlates with this appearance, which means that a taurodontal tooth has a large pulp chamber and apically positioned furcations. This dental anomaly may be associated with different syndromes and congenital discoders. The case report presents the patient of a rare case of taurodontism in the mandibular second premolar with chronic periodontitis. Endodontic treatment was performed after dental history and clinical examination. Special care is required in all segments of endodontic treatment of a taurodontal tooth from the identification orifice, canal exploration, determining working length, cleaning and shaping and obturation of the root canal. Precurved K-file was used for canal exploration and location of the furcation. One mesial and one distal canal with the buccal position were identified in the apical third of the root canal. The working lengths of two canals were determined by radiographic interpretation with two K-files in each canal and verified with the apex locator. During canal instrumentation, the third canal was located in the disto-lingual position. The working length of the third canal was established using the apex locator. Thorough knowledge of tooth anatomy and its variations can lead to lower percentage of endodontic failure. Each clinical case involving these teeth should be investigated carefully, clinically and radiographically to detect additional root canals. High quality radiographs from different angles and proper instrumentarium improve the quality of endodontic procedure.

Use of cone-beam computed tomography to evaluate root and canal morphology of mandibular first and second molars in Turkish individuals

PubMed Central

Sekerci, Ahmet E.; Dinçer, Asiye N.; Cayabatmaz, Muhammed; Zorba, Yahya O.

2013-01-01

Objective: The aim of this study was to investigate the root and canal morphology of mandibular first and second molars in a Turkish population by using cone beam computed tomography (CBCT). Study design: CBCT images of mandibular first (n = 823) and second molar (n = 925) teeth from 605 Turkish patients were analyzed. The root canal configurations were classified according to the method of Vertucci. Results: The majority of mandibular molars (95.8% of first molars, 85.4% of second molars) had two separate roots; however, three roots were identified in 2.06% of first molars and 3.45% of second molars. C-shaped canals occurred 0.85% of first molars and 4.1% of second molars. Three canals were found in 79.9% of first molars and 72.8% of second molars. Most distal roots had a simple type I configuration, whereas mesial roots had more complex canal systems, with more than one canal. The most common root morphology of first and second molars is the two rooted morphology with three canals. Both the mesial and distal roots showed wide variations in canal anatomy with type IV and type I canal configuration predominating in the mesial and distal roots, respectively. Conclusion: Vertucci type I and IV canal configurations were the most prevalent in the distal and mesial roots, respectively, of both the mandibular first and second permanent molar teeth. Key words:Cone-beam CT, Turkish, mandibular molars, root and canal morphology. PMID:23524421

30. VIEW OF TWIN FALLS MAIN CANAL FROM BRIDGE LOOKING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

30. VIEW OF TWIN FALLS MAIN CANAL FROM BRIDGE LOOKING WEST DOWNSTREAM. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

24. TWIN FALLS MAIN CANAL HEADWORKS, DOWNSTREAM LOOKING TOWARD THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

24. TWIN FALLS MAIN CANAL HEADWORKS, DOWNSTREAM LOOKING TOWARD THE EAST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

Morphometric study of the lumbar spinal canal in the Korean population.

PubMed

Lee, H M; Kim, N H; Kim, H J; Chung, I H

1995-08-01

The anatomic dimensions of the vertebral body and spinal canal of the lumbar spine were analyzed in Koreans. To determine the normal dimension of the lumbar spinal canal in Koreans, to determine whether there are any racial differences in the morphometry of the lumbar spinal canal, and to provide criteria for diagnosing spinal stenosis in the Far Eastern Asian. Some radiologic and anatomic studies have been conducted regarding the size of the lumbar spinal canal of whites and blacks in western and African countries. One-thousand-eight-hundred measurements were performed on the transverse and sagittal diameters of vertebral bodies and spinal canals using complete sets of 90 lumbar vertebrae. The mean mid-sagittal diameter of the lumbar spinal canal in the Korean population was less than that measured in white and African populations, but there was no significant differences between the Korean, white, and African populations regarding the transverse diameter of the lumbar spinal canal. The mid-sagittal diameter of the lumbar spinal canal is narrowest in the Far Eastern Asian population; the radiologic criteria of spinal stenosis should be reconsidered for these people.

[Shaping ability of two nickel-titanium rotary systems in simulated S-shaped canals].

PubMed

Luo, Hong-xia; Huang, Ding-ming; Zhang, Fu-hua; Tan, Hong; Zhou, Xue-dong

2008-01-01

To evaluate the shaping ability of two nickel-titanium rotary systems (ProTaper and Hero642) in simulated S-shaped canals. Thirty simulated S-shaped canals were randomly divided into three groups and prepared by ProTaper, Hero642, ProTaper combined with Hero642 respectively. All the canals were scanned before and after instrumentation, and the amount of material removed in the inner and outer wall and the canal width after instrumentation were measured with a computer image analysis program. There was significant difference in the amount of material removed at the inner side of apical curvature and outer side of apex between ProTaper combined with Hero642 and ProTaper files (P < 0.05) at the same tip size. The inner and outer wall of the canals were evenly prepared by ProTaper combined with Hero642, and the taper of canals were better than those prepared by Hero642. ProTaper combined with Hero 642 had better shaping ability to maintain the original shape and could create good taper canals in the simulated S-shaped canal model.

Endodontic treatment of mandibular molars with atypical root canal anatomy: reports of 4 cases.

PubMed

Chauhan, Raju; Singh, Shweta

2015-01-01

The variations in root canal anatomy of multirooted teeth represent a continuous challenge to endodontic diagnosis and treatment. Although the most common configuration of mandibular molars is one containing 2 roots and 3 root canals, there are many different combinations. Very rarely, an additional third (supernumerary) root is seen. When it is located distolingually to the main distal root, this third root is called radix entomolaris (RE), and when it is located mesiobuccally to the mesial root, it is called radix paramolaris (RP). Variations of root canal systems need not always be in the form of extra roots or extra canals. Single roots with single canals can also occur. A general dentist should be aware of these unusual root canal morphologies in mandibular molars for the success of endodontic treatment. These case reports describe the root canal treatment of a case of RE in the mandibular first molar, 2 rare cases of RP (1 each in the mandibular first and second molars), and a mandibular second molar with a single root and root canal.

Modelling the vestibular head tilt response.

PubMed

Heibert, D; Lithgow, B

2005-03-01

This paper attempts to verify the existence of potentially diagnostically significant periodic signals thought to exist in recordings of neural activity originating from the vestibular nerve, following a single tilt of the head. It then attempts to find the physiological basis of this signal, in particular focusing on the mechanical response of the vestibular system. Simple mechanical models of the semi circular canals having angular velocities applied to them were looked at. A simple single canal model was simulated using CFX software. Finally, a simple model of all three canals with elastic duct walls and a moving cupula was constructed. Pressure waves within the canals were simulated using water hammer or pressure transient theory. In particular, it was investigated whether pressure waves within the utricle following a square pulse angular velocity applied to the canal(s) may be responsible for quasi-periodic oscillatory signals. The simulations showed that there are no pressure waves resonating within the canals following a square pulse angular velocity applied to the canal(s). The results show that the oscillatory signals are most likely not mechanical in origin. It was concluded that further investigation is required.

Maxillary molars with morphologic variations of the palatal root canals: a report of four cases.

PubMed

Holderrieth, Silke; Gernhardt, Christian Ralf

2009-07-01

The purpose of this article was to show the importance of the knowledge of the anatomy of root canals. Unusual root and root canal morphologies associated with both buccal roots of upper molars have been recorded in several studies in the literature. However, scientific information focusing on variations of the palatal root is rare. In this report, four cases are presented involving the root canal treatment of maxillary first and second molars with unusual morphologic configurations of the palatal root canals. During root canal treatment, type IV and V configurations as defined by Vertucci of the palatal canals of two first and two second maxillary molars were identified. After mechanical instrumentation, the canals were obturated. Radiologic and clinical re-evaluation showed no signs of inflammation. This report describes and discusses the possibility of different root and canal variations of the maxillary molars from a clinical point of view. Anatomic variations can occur in any tooth, and palatal roots of maxillary first and second molars are no exception. Therefore, careful examination of radiographs and internal anatomy of teeth is essential.

Promoted ignition of oxygen regulators

NASA Technical Reports Server (NTRS)

Newton, Barry E.; Langford, Richard K.; Meyer, Gene R.

1989-01-01

An investigation has been conducted of the ignition-containment capability of 12 oxygen regulators contaminated by various levels of hydrocarbon oils and subjected to promoted ignition. The regulators inlets were pressurized to 15.2 MPa with gaseous oxygen, and the oil was ignited by an electrical arc located upstream of the test article inlet port; the flame was allowed to propagate with the oxygen flow throughout the regulator internal cavities. The resulting reactions, which ranged in character from complete containment of the promoted ignition for one two-stage regulator to extensive burning and explosive energy release for several other (both single- and double-stage) regulators, indicate the need to prevent oil from being introduced into regulators.

Promoted ignition of oxygen regulators

NASA Astrophysics Data System (ADS)

Newton, Barry E.; Langford, Richard K.; Meyer, Gene R.

An investigation has been conducted of the ignition-containment capability of 12 oxygen regulators contaminated by various levels of hydrocarbon oils and subjected to promoted ignition. The regulators inlets were pressurized to 15.2 MPa with gaseous oxygen, and the oil was ignited by an electrical arc located upstream of the test article inlet port; the flame was allowed to propagate with the oxygen flow throughout the regulator internal cavities. The resulting reactions, which ranged in character from complete containment of the promoted ignition for one two-stage regulator to extensive burning and explosive energy release for several other (both single- and double-stage) regulators, indicate the need to prevent oil from being introduced into regulators.

Vane clocking effects in an embedded compressor stage

NASA Astrophysics Data System (ADS)

Key, Nicole Leanne

The objective of this research was to experimentally investigate the effects of vane clocking, the circumferential indexing of adjacent vane rows with similar vane counts, in an embedded compressor stage. Experiments were performed in the Purdue 3-Stage Compressor, which consists of an IGV followed by three stages. The IGV, Stator 1, and Stator 2 have identical vane counts of 44, and the effects of clocking were studied on Stage 2. The clocking configuration that located the upstream vane wake on the Stator 2 leading edge was identified with total pressure measurements at the inlet to Stator 2 and confirmed with measurements at the exit of Stator 2. For both loading conditions, the total temperature results showed that there was no measurable change associated with vane clocking in the amount of work done on the flow. At design loading, the change in stage efficiency with vane clocking was 0.27 points between the maximum and minimum efficiency clocking configurations. The maximum efficiency configuration was the case where the Stator 1 wake impinged on the Stator 2 leading edge. This condition produced a shallower and thinner Stator 2 wake compared to the clocking configuration that located the wake in the middle of the Stator 2 passage. By locating the Stator 1 wake at the leading edge, it dampened the Stator 2 boundary layer response to inlet fluctuations associated with the Rotor 2 wakes. At high loading, the change in Stage 2 efficiency increased to 1.07 points; however, the maximum efficiency clocking configuration was the case where the Stator 1 wake passed through the middle of the downstream vane passage. At high loading, the flow physics associated with vane clocking were different than at design loading because the location of the Stator 1 wake fluid on the Stator 2 leading edge triggered a boundary layer separation on the suction side of Stator 2 producing a wider and deeper wake. Vane clocking essentially affects the amount of interaction between the upstream vane wake and the boundary layer of the downstream vane. Whether this dampens the adverse effects of the rotor wakes or triggers boundary layer separation will depend on the flow conditions such as Reynolds number, turbulence intensity, and pressure gradient (vane loading), to name a few.

Shock Tube and Ballistic Range Facilities at NASA Ames Research Center

DTIC Science & Technology

2010-04-01

in gun performance and launching techniques enabled Mach numbers over 10 to be realized at flight-relevant Reynolds numbers. Although the SSFF...contoured nozzle produced an accelerating supersonic flow with a concomitant exponential decay in density. A two-stage light gas gun fired models upstream...km/s, or Mach 50. Such extreme conditions could not be met by a counterflow facility consisting of the highest performance light gas gun and a

50 CFR 226.219 - Critical habitat for the Southern Distinct Population Segment of North American Green Sturgeon...

Code of Federal Regulations, 2010 CFR

2010-10-01

... River at 37°58′22″ N./121°34′40″ W.); Sand Mound Slough (all reaches upstream from 37°58′37″ N./121°37... sills and shelves, cobble and gravel, or hard clean sand, with interstices or irregular surfaces to... survival of all life stages. (iv) Water quality. Water quality, including temperature, salinity, oxygen...

22. TWIN FALLS MAIN CANAL HEADWORKS WITH MILNER DAM IN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

22. TWIN FALLS MAIN CANAL HEADWORKS WITH MILNER DAM IN DISTANCE; LOOKING EAST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

23. TWIN FALLS MAIN CANAL HEADWORKS WITH MILNER DAM IN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. TWIN FALLS MAIN CANAL HEADWORKS WITH MILNER DAM IN DISTANCE; LOOKING NORTHEAST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

14. VIEW OF WESTERN CANAL AT THE SALT RIVER PROJECT'S ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. VIEW OF WESTERN CANAL AT THE SALT RIVER PROJECT'S KYRENE STEAM POWER PLANT, TEMPE. THE WESTERN CANAL BEGINS TO TURN NORTH AT THIS POINT, AND DIVERTS WATER TO THE HIGHLINE PUMP PLANT AND THE KYRENE LATERAL. THE KYRENE PLANT INLET (LEFT-CENTER) ALSO DIVERTS CANAL WATER FOR PLANT OPERATION AND COOLING. - Western Canal, South side of Salt River between Tempe, Phoenix & Mesa, Mesa, Maricopa County, AZ

Effect of diode laser and ultrasonics with and without ethylenediaminetetraacetic acid on smear layer removal from the root canals: A scanning electron microscope study.

PubMed

Amin, Khalid; Masoodi, Ajaz; Nabi, Shahnaz; Ahmad, Parvaiz; Farooq, Riyaz; Purra, Aamir Rashid; Ahangar, Fayaz Ahmad

2016-01-01

To evaluate the effect of diode laser and ultrasonics with and without ethylenediaminetetraacetic acid (EDTA) on the smear layer removal from root canals. A total of 120 mandibular premolars were decoronated to working the length of 12 mm and prepared with protaper rotary files up to size F3. Group A canals irrigated with 1 ml of 3% sodium hypochlorite (NaOCl) followed by 3 ml of 3% NaOCl. Group B canals irrigated with 1 ml of 17% EDTA followed by 3 ml of 3% NaOCl. Group C canals lased with a diode laser. Group D canals were initially irrigated with 0.8 ml of 17% EDTA the remaining 0.2 ml was used to fill the root canals, and diode laser application was done. Group E canals were irrigated with 1 ml distilled water with passive ultrasonic activation, followed by 3 ml of 3% NaOCl. Group F canals were irrigated with 1 ml EDTA with passive ultrasonic activation, followed by 3 ml of 3% NaOCl. Scanning electron microscope examination of canals was done for remaining smear layer at coronal middle and apical third levels. Ultrasonics with EDTA had the least smear layer scores. Diode laser alone performed significantly better than ultrasonics.

An in vitro study to find the incidence of mesiobuccal 2 canal in permanent maxillary first molars using three different methods.

PubMed

Vasundhara, V; Lashkari, Krishna Prasada

2017-01-01

In-vitro study was done to evaluate the incidence of MB2 canals using three different methods (CBCT, CLINICAL ANALYSIS AND DENTAL LOUPES) and to compare the efficacy of the three methods in identifying the incidence of MB2 canals in maxillary permanent first molars. The study sample consisted of 120 extracted intact permanent maxillary molars. These extracted teeth were subjected to CBCT. Later the teeth were access opened with naked eye to find the incidence of MB2 canal, and then the teeth were visualised under dental loupe to locate MB2 canal if they were missed under naked eye. Results was statistically analysed by Mc Nemar's tests with Bonferroni correction, Chi square test and Cochran's Q test. CBCT showed high incidence (68.3%) of MB2 canal in maxillary first molars and it showed to be a reliable method in detecting MB2 canal. When compared to dental loupe (52.5%) and naked eye (25%), the dental loupe improved the detection of MB2 canal. Within the parameter of this study in detecting the incidence of MB2 canal, using CBCT dental loupes and naked eye, detection of MB2 canal was significantly higher with CBCT followed by dental loupe and least with naked eye.

Atmospheric mercury footprints of nations.

PubMed

Liang, Sai; Wang, Yafei; Cinnirella, Sergio; Pirrone, Nicola

2015-03-17

The Minamata Convention was established to protect humans and the natural environment from the adverse effects of mercury emissions. A cogent assessment of mercury emissions is required to help implement the Minamata Convention. Here, we use an environmentally extended multi-regional input-output model to calculate atmospheric mercury footprints of nations based on upstream production (meaning direct emissions from the production activities of a nation), downstream production (meaning both direct and indirect emissions caused by the production activities of a nation), and consumption (meaning both direct and indirect emissions caused by final consumption of goods and services in a nation). Results show that nations function differently within global supply chains. Developed nations usually have larger consumption-based emissions than up- and downstream production-based emissions. India, South Korea, and Taiwan have larger downstream production-based emissions than their upstream production- and consumption-based emissions. Developed nations (e.g., United States, Japan, and Germany) are in part responsible for mercury emissions of developing nations (e.g., China, India, and Indonesia). Our findings indicate that global mercury abatement should focus on multiple stages of global supply chains. We propose three initiatives for global mercury abatement, comprising the establishment of mercury control technologies of upstream producers, productivity improvement of downstream producers, and behavior optimization of final consumers.

Decreased levels of matrix metalloproteinase-2 in root-canal exudates during root canal treatment.

PubMed

Pattamapun, Kassara; Handagoon, Sira; Sastraruji, Thanapat; Gutmann, James L; Pavasant, Prasit; Krisanaprakornkit, Suttichai

2017-10-01

To determine the matrix metalloproteinase-2 (MMP-2) levels in root-canal exudates from teeth undergoing root-canal treatment. The root-canal exudates from six teeth with normal pulp and periradicular tissues that required intentional root canal treatment for prosthodontic reasons and from twelve teeth with pulp necrosis and asymptomatic apical periodontitis (AAP) were sampled with paper points for bacterial culture and aspirated for the detection of proMMP-2 and active MMP-2 by gelatin zymography and the quantification of MMP-2 levels by ELISA. By gelatin zymography, both proMMP-2 and active MMP-2 were detected in the first collection of root-canal exudates from teeth with pulp necrosis and AAP, but not from teeth with normal pulp, and their levels gradually decreased and disappeared at the last collection. Consistently, ELISA demonstrated a significant decrease in MMP-2 levels in the root-canal exudates of teeth with pulp necrosis and AAP following root canal procedures (p<0.05). Furthermore, the MMP-2 levels were significantly lower in the negative bacterial culture than those in the positive bacterial culture (p<0.001). The levels of MMP-2 in root-canal exudates from teeth with pulp necrosis and AAP were gradually reduced during root canal procedures. Future studies are required to determine if MMP-2 levels may be used as a biomolecule for the healing of apical lesions, similar to the clinical application of MMP-8 as a biomarker. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bony pelvic canal size and shape in relation to body proportionality in humans.

PubMed

Kurki, Helen K

2013-05-01

Obstetric selection acts on the female pelvic canal to accommodate the human neonate and contributes to pelvic sexual dimorphism. There is a complex relationship between selection for obstetric sufficiency and for overall body size in humans. The relationship between selective pressures may differ among populations of different body sizes and proportions, as pelvic canal dimensions vary among populations. Size and shape of the pelvic canal in relation to body size and shape were examined using nine skeletal samples (total female n = 57; male n = 84) from diverse geographical regions. Pelvic, vertebral, and lower limb bone measurements were collected. Principal component analyses demonstrate pelvic canal size and shape differences among the samples. Male multivariate variance in pelvic shape is greater than female variance for North and South Africans. High-latitude samples have larger and broader bodies, and pelvic canals of larger size and, among females, relatively broader medio-lateral dimensions relative to low-latitude samples, which tend to display relatively expanded inlet antero-posterior (A-P) and posterior canal dimensions. Differences in canal shape exist among samples that are not associated with latitude or body size, suggesting independence of some canal shape characteristics from body size and shape. The South Africans are distinctive with very narrow bodies and small pelvic inlets relative to an elongated lower canal in A-P and posterior lengths. Variation in pelvic canal geometry among populations is consistent with a high degree of evolvability in the human pelvis. Copyright © 2013 Wiley Periodicals, Inc.

Measurement of the percentage of root filling in oval-shaped canals obturated with Thermafil Obturators and Beefill 2in1: In vitro study

PubMed Central

Collado-Castellanos, Nicolás; Alegre-Domingo, Teresa; Dolz-Solsona, María; Faus-Matoses, Vicente

2015-01-01

Background The aim of the study was to measure the percentage of root canal fillings in long oval canals obturated with thermoplasticized gutta-percha techniques, Beefill 2in1® and Thermafil Obturators®. Material and Methods Fifty four mandibular incisors were selected after bucco-lingual and mesio-distal radiographs showed at 5 mm from apex an internal long:short diameter ≥2. Teeth were instrumented with Protaper Universal and divided in two groups of 27. Group 1 was obturated with Thermafil Obturators® and group 2 with Beefill 2in1®. Two horizontal sections were cut at 5 and 7 mm from the apex and photographed in a stereo-microscope. The total area of the canal and filled canal in cross-sections were measured with AutoCad and the percentages of gutta-percha-sealer and voids in the canal were obtained. Results Both systems achieved high percentage of filled canal, Thermafil 96.8% and Beefill 2in1 98.9%. The percentages of voids in both groups were very low. No significant differences were found between the two groups . The percentage obtained at 5 and 7 mm from the apex in both groups showed no significant difference. Conclusions The percentages of filled canal (gutta-percha-sealer) were high and these two thermoplasticized techniques are suitable for long oval canals obturation. Key words:Long oval canal, oval canal, thermoplasticized obturation. PMID:26155350

Measurement of the percentage of root filling in oval-shaped canals obturated with Thermafil Obturators and Beefill 2in1: In vitro study.

PubMed

Faus-Llácer, Vicente; Collado-Castellanos, Nicolás; Alegre-Domingo, Teresa; Dolz-Solsona, María; Faus-Matoses, Vicente

2015-04-01

The aim of the study was to measure the percentage of root canal fillings in long oval canals obturated with thermoplasticized gutta-percha techniques, Beefill 2in1® and Thermafil Obturators®. Fifty four mandibular incisors were selected after bucco-lingual and mesio-distal radiographs showed at 5 mm from apex an internal long:short diameter ≥2. Teeth were instrumented with Protaper Universal and divided in two groups of 27. Group 1 was obturated with Thermafil Obturators® and group 2 with Beefill 2in1®. Two horizontal sections were cut at 5 and 7 mm from the apex and photographed in a stereo-microscope. The total area of the canal and filled canal in cross-sections were measured with AutoCad and the percentages of gutta-percha-sealer and voids in the canal were obtained. Both systems achieved high percentage of filled canal, Thermafil 96.8% and Beefill 2in1 98.9%. The percentages of voids in both groups were very low. No significant differences were found between the two groups . The percentage obtained at 5 and 7 mm from the apex in both groups showed no significant difference. The percentages of filled canal (gutta-percha-sealer) were high and these two thermoplasticized techniques are suitable for long oval canals obturation. Key words:Long oval canal, oval canal, thermoplasticized obturation.

Deviations of Mesial Root Canals of Mandibular First Molar Teeth at the Apical Third: A Micro-computed Tomographic Study.

PubMed

Keles, Ali; Keskin, Cangül

2018-06-01

The present study aimed to quantitatively analyze apical foramen deviations of mesial root canals of mandibular first molar teeth by means of micro-computed tomographic (micro-CT) imaging. Micro-CT images of the mesial roots of 109 mandibular first molar teeth with independent mesiobuccal (MB) and mesiolingual (ML) root canals were analyzed. The deviations of the apical foramina of the MB, ML, and middle mesial root canals from the anatomic apex were measured. The vertical distance between the apical foramina of each mesial root canal in relation to each other was also calculated. The distances from the apical foramina of the MB, ML, and middle mesial root canals to the anatomic apex of the mesial root were up to 2.51 mm, 3.21 mm, and 5.67 mm, respectively. There was no significant difference between the deviations of MB and ML root canals from each other (P > .05). The middle mesial root canal showed the greatest deviation compared with the MB and ML canals (P < .05). The apical foramina of mesial root canals of mandibular first molar teeth showed greater variations from each other and anatomic apices than previously reported. Clinically, the use of electronic apex locators for the detection of minor apical foramen of each mesial root canal is of the utmost important. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Morphometrics of the Southern Green Stink Bug [Nezara viridula (L.) (Hemiptera: Pentatomidae)] Stylet Bundle.

PubMed

Esquivel, J F; Droleskey, R E; Ward, L A; Harvey, R B

2018-03-29

The southern green stink bug, Nezara viridula (L.) (Hemiptera: Pentatomidae), is a cosmopolitan pest of high-value cash crops, including cotton (Gossypium hirsutum L.; Malvales: Malvaceae). The pest can ingest and transmit disease-causing bacterial and fungal pathogens of cotton. We hypothesized that the size of the food canal may contribute to selective transmission, as observed in previous reports. The objective of this study was to examine food canal size and other morphometric parameters of the southern green stink bug stylet bundle at two locations (labium and head) to improve our understanding of factors that may contribute to pathogen transmission. For the food canal, females possessed significantly larger canals than males, major axes were significantly longer than minor axes, and canal sizes were numerically higher at the labium compared with the head. For salivary canal, mean axes lengths were similar between sexes and the head and labium. For both food and salivary canals, axes lengths were longer and area was larger at the labium compared with the head. These findings indicate the presence of a "funnel effect" with canals becoming narrower proximally. Sex and location significantly affected the size of the intact stylet bundle. Results indicate the food canal size was not a factor affecting previously observed selective passive transmission. Major and minor axes measurements, coupled with morphological observations of canal shapes and observed "funnel effect" in the food and salivary canals, improve our understanding of the hemipteran stylet bundle and its relationship with the insect's internal morphology.

Comparison of preparation of curved root canals with Hyflex CM and Revo-S rotary nickel-titanium instruments.

PubMed

Bürklein, S; Börjes, L; Schäfer, E

2014-05-01

To compare the shaping ability of three different nickel-titanium rotary instruments during the preparation of curved root canals in extracted teeth. A total of 60 root canals with curvatures ranging between 25° and 35° were divided into three groups of 20 canals. Based on radiographs taken prior to instrumentation, the groups were balanced with respect to the angle and the radius of canal curvature. Canals were prepared to a final apical size of 35 using Mtwo, Hyflex CM, and Revo-S. Using pre- and post-instrumentation radiographs, straightening of the canal curvatures was determined with a computer image analysis program. Preparation time, changes of working length and instrument failures were also recorded. These data were analysed statistically using anova and Student-Newman-Keuls test. During preparation, no file fractured. Mtwo and Hyflex CM maintained the original canal curvature significantly better than Revo-S (P < 0.05). Instrumentation with Mtwo and Hyflex CM was significantly faster than with Revo-S and resulted in less loss of working length (P < 0.05), whilst no significant differences were obtained between Mtwo and Hyflex CM (P > 0.05). Under the conditions of this study, Mtwo and Hyflex CM respected the original canal curvature well and were safe to use. The use of Revo-S instruments required more time to prepare the curved canals and resulted in more pronounced canal straightening compared with Mtwo and Hyflex CM. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Ex Vivo Comparison of Mtwo and RaCe Rotary File Systems in Root Canal Deviation: One File Only versus the Conventional Method.

PubMed

Aminsobhani, Mohsen; Razmi, Hasan; Nozari, Solmaz

2015-07-01

Cleaning and shaping of the root canal system is an important step in endodontic therapy. New instruments incorporate new preparation techniques that can improve the efficacy of cleaning and shaping. The aim of this study was to compare the efficacy of Mtwo and RaCe rotary file systems in straightening the canal curvature using only one file or the conventional method. Sixty mesial roots of extracted human mandibular molars were prepared by RaCe and Mtwo nickel-titanium (NiTi) rotary files using the conventional and only one rotary file methods. The working length was 18 mm and the curvatures of the root canals were between 15-45°. By superimposing x-ray images before and after the instrumentation, deviation of the canals was assessed using Adobe Photoshop CS3 software. Preparation time was recorded. Data were analyzed using three-way ANOVA and Tukey's post hoc test. There were no significant differences between RaCe and Mtwo or between the two root canal preparation methods in root canal deviation in buccolingual and mesiodistal radiographs (P>0.05). Changes of root canal curvature in >35° subgroups were significantly more than in other subgroups with smaller canal curvatures. Preparation time was shorter in one file only technique. According to the results, the two rotary systems and the two root canal preparation methods had equal efficacy in straightening the canals; but the preparation time was shorter in one file only group.

Identification of possible factors impacting dental students' ability to locate MB2 canals in maxillary molars.

PubMed

Park, Ellen; Chehroudi, Babak; Coil, Jeffrey M

2014-05-01

This study examined the effect of the access size and straight-line path of access on third-year dental students' ability to locate a second mesiobuccal (MB2) canal in maxillary first and second molars. One hundred and six third-year dental students at one Faculty of Dentistry performed simulated root canal treatment with the aid of 2x magnification loupes on extracted teeth. A postgraduate endodontic student subsequently made a reasonable search for an untreated MB2 canal with the aid of a dental operating microscope. The mesiobuccal roots were then sectioned horizontally for determination of the canal configuration. The dental students were able to treat an MB2 canal in 15.8 percent of the teeth, but this was not associated with satisfactory access criteria. The postgraduate endodontic student identified an MB2 canal in 54.7 percent of the remaining tooth samples excluding those where the MB2 canal was found by the dental students; this represented 94.3 percent of those teeth confirmed by horizontal sectioning of the root to have an MB2 canal. The postgraduate student troughed, on average, 2.6 mm before negotiating the MB2 canal. As satisfactory access criteria and straight-line path of access did not correlate with the dental students' ability to find a second mesiobuccal canal, this result has important implications for educational goals with respect to endodontic treatment of maxillary molar teeth.

An original micro-CT study and meta-analysis of the internal and external anatomy of maxillary molars - implications for endodontic treatment.

PubMed

Tomaszewska, Iwona M; Jarzębska, Anna; Skinningsrud, Bendik; Pękala, Przemysław A; Wroński, Sebastian; Iwanaga, Joe

2018-05-07

The aim of this work was to conduct a radiological micro-CT study and meta-analysis to determine the morphological features of the root canal anatomy of the maxillary molars. The radiological study included micro-CT scans of 110 maxillary first molars and 98 maxillary second molars. To identify articles eligible for inclusion in our meta-analysis, PubMed, Embase, and Web of Science were search comprehensively. The following data were extracted: study type (cadaveric, intraoperative or imaging), Vertucci types of canal configuration, presence/number of canals, roots, apical foramina, apical deltas, and inter-canal communications. The mesiobuccal root was the most variable with respect to canal configuration, type I being the most common configuration followed by type II and type IV. Type I was the most common canal configuration in the distobuccal and palatal root. Regarding the number of canals in the maxillary first and second molars, one canal was most prevalent in all roots of the three molars, except for the mesiobuccal root of maxillary first molar, in which two canals were most prevalent. The most prevalent number of roots in all maxillary molars was three. Knowledge of endodontic anatomy determines the parameters of root canal treatment and significantly affects the probability of success. It is therefore especially important to know the morphology of the root canal system in order to perform endodontic treatment correctly. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

148. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

148. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER DAM; HEADGATES AT INLET, SOUTHWEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

98. SHOESTRING, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY NORTHWEST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

98. SHOESTRING, TWIN FALLS MAIN CANAL, TWIN FALLS COUNTY NORTHWEST OF MURTAUGH, IDAHO; PROFILE VIEW, SOUTH. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

16. VIEW OF HIGHLINE CANAL PIPELINE OUTLET, SHOWING THE OUTLET, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

16. VIEW OF HIGHLINE CANAL PIPELINE OUTLET, SHOWING THE OUTLET, A GROUNDWATER PUMP (LEFT), AND THE SOUTH BRANCH OF THE CANAL (FOREGROUND), August 1989 - Highline Canal & Pumping Station, South side of Salt River between Tempe, Phoenix & Mesa, Tempe, Maricopa County, AZ

2. VIEW SOUTH, GENERAL VIEW SHOWING CANAL, CANAL SPILLWAY ON ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. VIEW SOUTH, GENERAL VIEW SHOWING CANAL, CANAL SPILLWAY ON LEFT, DRAIN GATE GATEHOUSE IN DISTANCE - Norwich Water Power Company, West bank of Shetucket River beginning opposite Second Street & extending .8 mile northward, Greenville section, Norwich, New London County, CT

Canalolithiasis of the superior semicircular canal: an anomaly in benign paroxysmal vertigo.

PubMed

Schratzenstaller, Bruno; Wagner-Manslau, Carola; Strasser, Gerhard; Arnold, Wolfgang

2005-10-01

According to the canalolithiasis theory, benign paroxysmal vertigo (BPPV) is caused by gravity-dependent movements of otoconial debris that collects in the endolymph of the posterior semicircular canal. Other parts of the vestibular organ are rarely affected, and it is mainly the horizontal canal that is affected by this atypical form of BPPV. Canalolithiasis of the superior semicircular canal must be considered an anomaly because the superior semicircular canal is the highest point of the vestibular organ and debris normally cannot collect in this special location. Until now, BPPV of the superior canal has mainly been dealt with theoretically in the literature. The authors present three patients with canalolithiasis of the superior semicircular canal and offer direct proof of the condition using high-resolution 3D MRI.

Endodontic management of permanent mandibular molars with 6 root canals: report of 3 cases.

PubMed

Malhotra, Amit; Ahlawat, Jyoti; Bansal, Chirag; Tahiliani, Divya

2016-01-01

Aberrations in the internal dental anatomy present challenges for clinicians performing endodontic therapy. These challenges have been partly resolved in recent years by a more comprehensive knowledge of root canal anatomy as well as advancements in the endodontic armamentarium. The aim of this case series is to describe successful root canal treatment, under magnification, in 3 cases of mandibular first molars with 6 root canals. Two of these teeth had 2 roots (mesial and distal) with 3 canals in each root; the third tooth had 3 root canals located mesially and 3 present distally as well as a radix entomolaris. A distal root with 3 canals is rare; however, it is important to look for such anatomical variations to ensure successful endodontic therapy.

Middle mesial canal of the permanent mandibular first molars: an anatomical challenge directly related to the outcome of endodontic treatment.

PubMed

Perlea, Paula; Nistor, Cristina Coralia; Imre, Marina; Gheorghiu, Irina Maria; Iliescu, Alexandru Andrei

2017-01-01

To effectively clean and shape the mandibular permanent first molars it is mandatory to understand in detail their complex internal anatomy. The middle mesial canal is an additional canal located between the usual mesiobuccal and mesiolingual canals in the mesial root of mandibular first molars. The incidence of the middle mesial canal, its relationship with main canals of the mesial root and the possibility for it to be negotiated is an important practical issue in endodontics. To identify the presence of this canal is mandatory. Accordingly, a modified endodontic access, the use of the operating microscope and periapical radiographs in two different horizontal projections are indicated to enhance the long-term favorable outcome of the endodontic treatment.

Temporal and Spatial Variation of Chemical Water Quality in a Contour Canal.

NASA Astrophysics Data System (ADS)

Swanson, L. A.; Lunn, R. J.

2004-12-01

Chemical water quality is a highly variable aspect of any water body. Historically numerous researchers have investigated the chemical variability of rivers, streams and wetlands, artificial water bodies such as canals have been largely neglected. Canals are typically hydraulically characterised by low flows and a lack of mixing processes. This can potentially lead to significant spatial variability in water chemistry, and as a result many canals in the UK regularly fail water quality targets at specific locations. Recent changes to UK legislation, following the European Water Framework Directive (2000/60/EC), have resulted in canals being subject to achieving `good ecological status'. In the case of canals, what constitutes `good ecological status' is largely unknown and little expertise is available since historically canal management has not been driven by chemical and ecological quality targets. Consequently, there is an urgent need for new research to determine the main factors influencing canal water quality and their ecological status. This research presents results from a study based on a UK contour canal, the Union Canal in central Scotland. The Union Canal typically demonstrates spatially and temporally variable levels of dissolved oxygen (DO) and orthophosphate (PO4-P): simultaneously, seasonal and diel fluctuations of DO and PO4-P are pronounced at a small number of locations. During 1995, minimum levels of DO along the canal length ranged from 9mgl-1 in Edinburgh to as low as 2mgl-1 approximately 20kms away, this then rose again to 8mgl-1 after a further distance of 2km. These acutely low levels of DO are coupled with events of excessive PO4-P up to 0.235mgl-1:10 times greater than those normally found in rivers, causing localised eutrophication and extensive fish kills. To determine the cause of the `hot spots' of poor water quality found on the Union Canal, simultaneous investigations of the hydraulic regime, spatial and temporal water quality variation and the canal's biological status were carried out. Velocity metering in the canal identified extremely low flow rates ~0.15m3s-1. A tracer testing procedure for the canal's low flow conditions was designed and implemented which identified a lack of rapid dispersion processes with D~0.133m3s-1. Water quality sampling consisted of a year-long programme of high frequency temporal and spatial sampling along the canal length. Observations demonstrate significant variability, with widely differing measurements of DO as little as 5m apart. In addition, spot samples of water quality taken from individual incoming field drains showed PO4-P concentrations up to 2mgl-1, with a predominance of nutrient bound clay and silt sediments that ultimately settle on the canal bed. Due to low dispersion rates, residence times for pollutants are long and field drains, in combination with navigational activity, may well be one of the primary causes of raised nutrient levels at some locations. This research has shown that canal water quality is highly spatially and temporally variable; far in excess of the variability normally found in river systems. This is mainly determined by a lack of hydraulic mixing and the presence of small quantities of incoming runoff water of very low quality. Whilst low in volume, incoming sediment from the drains appears to strongly influence the nearby canal water quality. These results have important consequences both for future monitoring strategies of canals and management of their gradual ecological improvement.

Comparison among manual instruments and PathFile and Mtwo rotary instruments to create a glide path in the root canal preparation of curved canals.

PubMed

Alves, Vanessa de Oliveira; Bueno, Carlos Eduardo da Silveira; Cunha, Rodrigo Sanches; Pinheiro, Sérgio Luiz; Fontana, Carlos Eduardo; de Martin, Alexandre Sigrist

2012-01-01

Nickel-titanium rotary instruments reduce procedural errors and the time required to finish root canal preparation. The goal of this study was to evaluate the occurrences of apical transportation and canal aberrations produced with different instruments used to create a glide path in the preparation of curved root canals, namely manual K-files (Dentsply Maillefer, Ballaigues, Switzerland) and PathFile (Dentsply Maillefer) and Mtwo (Sweden and Martina, Padua, Italy) nickel-titanium rotary files. The mesial canals of 45 mandibular first and second molars (with curvature angles between 25° and 35°) were selected for this study. The specimens were divided randomly into 3 groups with 15 canals each, and canal preparation was performed by an endodontist using #10-15-20 K-type stainless steel manual files (group M), #13-16-19 PathFile rotary instruments (group PF), and #10-15-20 Mtwo rotary instruments (group MT). The double digital radiograph technique was used, pre- and postinstrumentation, to assess whether apical transportation and/or aberration in root canal morphology occurred. The initial and final images of the central axis of the canals were compared by superimposition through computerized analysis and with the aid of magnification. The specimens were analyzed by 3 evaluators, whose calibration was checked using the Kendall agreement test. No apical transportation or aberration in root canal morphology occurred in any of the teeth; therefore, no statistical analysis was conducted. Neither the manual instruments nor the PathFile or Mtwo rotary instruments used to create a glide path had any influence on the occurrence of apical transportation or produced any canal aberration. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Micro-computed tomographic analysis of the root canal morphology of the distal root of mandibular first molar.

PubMed

Filpo-Perez, Carolina; Bramante, Clovis Monteiro; Villas-Boas, Marcelo Haas; Húngaro Duarte, Marco Antonio; Versiani, Marco Aurélio; Ordinola-Zapata, Ronald

2015-02-01

The aim of this study was to evaluate the morphologic aspects of the root canal anatomy of the distal root of a mandibular first molar using micro-computed tomographic analysis. One-hundred distal roots of mandibular first molars were scanned using a micro-computed tomographic device at an isotropic resolution of 19.6 μm. The percentage frequency distribution of the morphologic configuration of the root canal was performed according to the Vertucci classification system. Two-dimensional parameters (area, perimeter, roundness, aspect ratio, and major and minor diameters) and the cross-sectional shape of the root canal were analyzed in the apical third at every 1-mm interval from the main apical foramen in roots presenting Vertucci types I and II configurations (n = 79). Data were statistically compared using the Kruskal-Wallis and Dunn tests with a significance level set at 5%. Seventy-six percent of the distal roots had a single root canal. Two, three, and four canals were found in 13%, 8%, and 3% of the sample, respectively. In 13 specimens, the configuration of the root canal did not fit into Vertucci's classification. Overall, 2-dimensional parameter values significantly increased at the 3-mm level (P < .05). The prevalence of oval canals was higher at the 1-mm level and decreased at the 5-mm level in which long oval and flattened canals were more prevalent. The distal roots of the mandibular first molars showed a high prevalence of single root canals. The prevalence of long oval and flattened canals increased in the coronal direction. In 13% of the samples, canal configurations that were not included in Vertucci's configuration system were found. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Endodontic shaping performance using nickel-titanium hand and motor ProTaper systems by novice dental students.

PubMed

Tu, Ming-Gene; Chen, San-Yue; Huang, Heng-Li; Tsai, Chi-Cheng

2008-05-01

Preparing a continuous tapering conical shape and maintaining the original shape of a canal are obligatory in root canal preparation. The purpose of this study was to compare the shaping performance in simulated curved canal resin blocks of the same novice dental students using hand-prepared and engine-driven nickel-titanium (NiTi) rotary ProTaper instruments in an endodontic laboratory class. Twenty-three fourth-year dental students attending China Medical University Dental School prepared 46 simulated curved canals in resin blocks with two types of NiTi rotary systems: hand and motor ProTaper files. Composite images were prepared for estimation. Material removed, canal width and canal deviation were measured at five levels in the apical 4 mm of the simulated curved canals using AutoCAD 2004 software. Data were analyzed using Wilcoxon's rank-sum test. The hand ProTaper group cut significantly wider than the motor rotary ProTaper group in the outer wall, except for the apical 0 mm point. The total canal width was cut significantly larger in the hand group than in the motor group. There was no significant difference between the two groups in centering canal shape, except at the 3 mm level. These findings show that the novice students prepared the simulated curved canal that deviated more outwardly from apical 1 mm to 4 mm using the hand ProTaper. The ability to maintain the original curvature was better in the motor rotary ProTaper group than in the hand ProTaper group. Undergraduate students, if following the preparation sequence carefully, could successfully perform canal shaping by motor ProTaper files and achieve better root canal geometry than by using hand ProTaper files within the same teaching and practicing sessions.

Comparison of canal transportation and centering ability of rotary protaper, one shape system and wave one system using cone beam computed tomography: An in vitro study

PubMed Central

Tambe, Varsha Harshal; Nagmode, Pradnya Sunil; Abraham, Sathish; Patait, Mahendra; Lahoti, Pratik Vinod; Jaju, Neha

2014-01-01

Aim: The aim of the present study was to compare the canal transportation and centering ability of Rotary ProTaper, One Shape and Wave One systems using cone beam computed tomography (CBCT) in curved root canals to find better instrumentation technique for maintaining root canal geometry. Materials and Methods: Total 30 freshly extracted premolars having curved root canals with at least 10 degrees of curvature were divided into three groups of 10 teeth each. All teeth were scanned by CBCT to determine the root canal shape before instrumentation. In Group 1, the canals were prepared with Rotary ProTaper files, in Group 2 the canals were prepared with One Shape files and in Group 3 canals were prepared with Wave One files. After preparation, post-instrumentation scan was performed. Pre-instrumentation and post-instrumentation images were obtained at three levels, 3 mm apical, 3 mm coronal and 8 mm apical above the apical foramen were compared using CBCT software. Amount of transportation and centering ability were assessed. The three groups were statistically compared with analysis of variance and Tukey honestly significant. Results: All instruments maintained the original canal curvature with significant differences between the different files. Data suggested that Wave One files presented the best outcomes for both the variables evaluated. Wave One files caused lesser transportation and remained better centered in the canal than One Shape and Rotary ProTaper files. Conclusion: The canal preparation with Wave One files showed lesser transportation and better centering ability than One Shape and ProTaper. PMID:25506145

Morphology of mandibular first molars analyzed by cone-beam computed tomography in a Korean population: variations in the number of roots and canals.

PubMed

Kim, Sin-Young; Kim, Bom Sahn; Woo, Jein; Kim, Yemi

2013-12-01

The aim of this study was to determine the root and canal morphology of the mandibular first molars in a Korean population of Mongolian origin by retrospective analysis of a large number of cone-beam computed tomography (CBCT) images. A total of 976 subjects with bilateral mandibular first molars were examined by using in vivo CBCT methods. The number and configuration of roots, the number of root canals, and the canal configuration based on Vertucci's classification were determined. Overall, 25.82% of examined molars had 3 roots, 73.51% had 2 roots, and 0.67% had 1 root. The incidence of fourth canal was 50.36%. A right-sided predominance was noted for extra distal roots (P < .001), whereas a left-sided predominance was observed for extra distal canals (P < .001). No significant sex-related differences were shown for their prevalence. The bilateral prevalence rate was 69.13% for extra distal roots and 78.08% for extra distolingual (DL) canals. In the mesial roots, type IV canal was the most frequent (76.86% for 2-rooted molars and 72.96% for 3-rooted molars). In the distal roots, type l was the most common (66.62% for 2-rooted molars and 99.40%-100% for 3-rooted molars). The incidence of 2 canals in distobuccal roots, first reported in this study, was 0.15%. Among mandibular first molars, there is a high prevalence of a separate DL root and/or a separate DL canal, and such molars commonly have 4 canals in the Korean population. CBCT is a useful tool for determining root and canal morphology. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Exploiting the potential of free software to evaluate root canal biomechanical preparation outcomes through micro-CT images.

PubMed

Neves, A A; Silva, E J; Roter, J M; Belladona, F G; Alves, H D; Lopes, R T; Paciornik, S; De-Deus, G A

2015-11-01

To propose an automated image processing routine based on free software to quantify root canal preparation outcomes in pairs of sound and instrumented roots after micro-CT scanning procedures. Seven mesial roots of human mandibular molars with different canal configuration systems were studied: (i) Vertucci's type 1, (ii) Vertucci's type 2, (iii) two individual canals, (iv) Vertucci's type 6, canals (v) with and (vi) without debris, and (vii) canal with visible pulp calcification. All teeth were instrumented with the BioRaCe system and scanned in a Skyscan 1173 micro-CT before and after canal preparation. After reconstruction, the instrumented stack of images (IS) was registered against the preoperative sound stack of images (SS). Image processing included contrast equalization and noise filtering. Sound canal volumes were obtained by a minimum threshold. For the IS, a fixed conservative threshold was chosen as the best compromise between instrumented canal and dentine whilst avoiding debris, resulting in instrumented canal plus empty spaces. Arithmetic and logical operations between sound and instrumented stacks were used to identify debris. Noninstrumented dentine was calculated using a minimum threshold in the IS and subtracting from the SS and total debris. Removed dentine volume was obtained by subtracting SS from IS. Quantitative data on total debris present in the root canal space after instrumentation, noninstrumented areas and removed dentine volume were obtained for each test case, as well as three-dimensional volume renderings. After standardization of acquisition, reconstruction and image processing micro-CT images, a quantitative approach for calculation of root canal biomechanical outcomes was achieved using free software. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

6. View southwest, culvert inlet with canal bank completely removed. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. View southwest, culvert inlet with canal bank completely removed. Left to right: back of headwall; tops of high inlet barrels; vertical transition wall between high inlet barrels and low, interior, inlet barrels; tops of low interior barrels; vertical heartening planks and low cutoff wall along former edge of canal bank; dewatered canal bed. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ

Endodontic management of contralateral mandibular first molars with six root canals

PubMed Central

Bhargav, Kambhampati; Sirisha, Kantheti; Jyothi, Mandava; Boddeda, Mohan Rao

2017-01-01

The knowledge of variations in root canal morphology is essential for a successful endodontic outcome. Contralateral mandibular molar with six root canals is a rare entity. Root canal treatment of mandibular molars with aberrant canal configuration can be diagnostically and technically challenging. While dealing with variant mandibular molars, mishaps may happen. This case report describes variations in contralateral mandibular molars and also an endodontic mishap while managing them. PMID:29259369

The Overexpression of TDP-43 Protein in the Neuron and Oligodendrocyte Cells Causes the Progressive Motor Neuron Degeneration in the SOD1 G93A Transgenic Mouse Model of Amyotrophic Lateral Sclerosis.

PubMed

Lu, Yi; Tang, Chunyan; Zhu, Lei; Li, Jiao; Liang, Huiting; Zhang, Jie; Xu, Renshi

2016-01-01

The recent investigation suggested that the TDP-43 protein was closely related to the motor neuron degeneration in amyotrophic lateral sclerosis (ALS), but the pathogenesis contributed to motor neuron degeneration largely remained unknown. Therefore, we detected the alteration of TDP-43 expression and distribution in the adult spinal cord of the SOD1 G93A transgenic mouse model for searching the possible pathogenesis of ALS. We examined the TDP-43 expression and distribution in the different anatomic regions, segments and neural cells in the adult spinal cord at the different stages of the SOD1 wild-type and G93A transgenic model by the fluorescent immunohistochemical technology. We revealed that the amount of TDP-43 positive cell was cervical>lumbar>thoracic segment, that in the ventral horn was more than that in the dorsal horn, a few of TDP-43 protein sparsely expressed and distributed in the other regions, the TDP-43 protein weren't detected in the white matter and the central canal. The TDP-43 protein was mostly expressed and distributed in the nuclear of neuron cells and the cytoplasm of oligodendrocyte cells of the gray matter surrounding the central canal of spinal cord by the granular shape in the SOD1 wild-type and G93A transgenic mice. The amount of TDP-43 positive cell significantly increased at the onset and progression stages of ALS following with the increase of neuron death in spinal cord, particularly in the ventral horn of cervical segment at the progression stage. Our results suggested that the overexpression of TDP-43 protein in the neuron and oligodendrocyte cell causes the progressive motor neuron degeneration in the ALS-like mouse model.

Anatomic study on mental canal and incisive nerve canal in interforaminal region in Chinese population.

PubMed

Xu, Yun; Suo, Ning; Tian, Xiufen; Li, Fei; Zhong, Guangxin; Liu, Xiaoran; Bao, Yongxing; Song, Tao; Tian, Hua

2015-08-01

This study was aimed to detect the positions of mental canal and incisive nerve canal as well as the prolongation of mandibular canal in interforaminal region in Chinese population to supply the reference data of the surgical safe zone in chin for clinicians. A total of 80 formalin-fixed semi-mandibles of Chinese adult cadavers were dissected, the positions and courses of mental canal and incisive nerve canal as well as the prolongation of mandibular canal in interforaminal region were measured. The mental foramina were present in all cases (100 %), and most of them were located below 2nd premolar (58.75 %). Accessory mental foramina were observed in 5 %. The anterior end of mandibular canal, extending along the course of 7.37 ± 1.10 mm above the lower border of mandible to interforaminal region about 3.54 ± 0.70 mm medial to the mental foramen, most often ended below between the two premolars (73.75 %), where it continued as the incisive nerve canal (100 %) and the mental canal (96.25 %). Mental canal, with the wall formed by compact bone, being 2.60 ± 0.60 mm in diameter and 4.01 ± 1.20 mm in length, opened into mental foramen. Incisive nerve canal, with the wall formed by thin compact bone and/or partly or completely by spongy bone, being 1.76 ± 0.27 mm in diameter and 24.87 ± 2.23 mm in length, extended to the incisor region along the course of 9.53 ± 1.43 mm above the lower border of mandible, and most often ended below the lateral incisor (70.00 %). This research recommended for chin operations in Chinese population: the surgical safe zone could be set in the region about over 4 mm anterior to the mental foramen, and over 12 mm above inferior border of mandible for anterior alveolar surgery, or within 9 mm above inferior border of mandible for genioplasty.

A reconstructed computerized tomographic comparison of Ni-Ti rotary GT files versus traditional instruments in canals shaped by novice operators.

PubMed

Gluskin, A H; Brown, D C; Buchanan, L S

2001-09-01

The aim of this study was to compare the effects of preparation with conventional stainless steel Flexofiles and Gates Glidden burs versus nickel-titanium GT rotary files in the shaping of mesial root canals of extracted mandibular molars. A total of 54 canals from 27 mesial roots of mandibular molar teeth were prepared using one of two methods by novice dental students. One canal in each root was prepared by a crown-down approach. utilizing stainless steel Flexofiles and Gates Glidden burs. The other canal was prepared using nickel-titanium GT rotary files in a crown-down fashion as recommended by the manufacturer. Preoperative CT scans of each root were recorded and 50 canal specimens were available for postoperative comparisons. Following canal shaping, postoperative scans were superimposed on the original images. Changes in canal area, canal transportation and thickness of remaining root structure at strategic levels of the root were analyzed. The time taken for each method was also noted. At the coronal and mid-root coronal one-third sections, the rotary GT files produced a significantly smaller postoperative canal area (P < 0.05). In the mid-root sections there was significantly less transportation of the root canal toward the furcation, and less thinning of the root structure with GT files compared to the stainless steel files (P < 0.05). Overall, there was greater conservation of structure coronally and more adequate shape in the mid-root level. The GT rotary technique was significantly faster than the stainless steel hand-held file technique (P < 0.0001). Two GT instruments fractured during the study. Under the conditions of this study, novice dental students were able to prepare curved root canals with Ni-Ti GT rotary files with less transportation and greater conservation of tooth structure, compared to canals prepared with hand instruments. The rotary technique was significantly faster.

[In vitro comparison of root canal preparation with step-back technique and GT rotary file--a nickel-titanium engine driven rotary instrument system].

PubMed

Krajczár, Károly; Tóth, Vilmos; Nyárády, Zoltán; Szabó, Gyula

2005-06-01

The aim of the authors' study was to compare the remaining root canal wall thickness and the preparation time of root canals, prepared either with step-back technique, or with GT Rotary File, an engine driven nickel-titanium rotary instrument system. Twenty extracted molars were decoronated. Teeth were divided in two groups. In Group 1 root canals were prepared with step-back technique. In Group 2 GT Rotary File System was utilized. Preoperative vestibulo-oral X-ray pictures were taken from all teeth with radiovisiograph (RVG). The final preparations at the mesiobuccal canals (MB) were performed with size #30 and palatinal/distal canals with size #40 instruments. Postoperative RVG pictures were taken ensuring the preoperative positioning. The working time was measured in seconds during each preparation. The authors also assessed the remaining root canal wall thickness at 3, 6 and 9 mm from the radiological apex, comparing the width of the canal walls of the vestibulo-oral projections on pre- and postoperative RVG pictures both mesially and buccally. The ratios of the residual and preoperative root canal wall thickness were calculated and compared. The largest difference was found at the MB canals of the coronal and middle third level of the root, measured on the distal canal wall. The ratio of the remaining dentin wall thickness at the coronal and the middle level in the case of step-back preparation was 0.605 and 0.754, and 0.824 and 0.895 in the cases of GT files respectively. The preparation time needed for GT Rotary File System was altogether 68.7% (MB) and 52.5% (D/P canals) of corresponding step-back preparation times. The use of GT Rotary File with comparison of standard step-back method resulted in a shortened preparation time and excessive damage of the coronal part of the root canal could be avoided.

Prevalence and morphometric analysis of three-rooted mandibular first molars in a Brazilian subpopulation

PubMed Central

Rodrigues, Clarissa Teles; de Oliveira-Santos, Christiano; Bernardineli, Norberti; Duarte, Marco Antonio Hungaro; Bramante, Clovis Monteiro; Minotti-Bonfante, Paloma Gagliardi; Ordinola-Zapata, Ronald

2016-01-01

ABSTRACT The knowledge of the internal anatomy of three-rooted mandibular molars may help clinicians to diagnose and plan the root canal treatment in order to provide adequate therapy when this variation is present. Objectives: To determine the prevalence of three-rooted mandibular molars in a Brazilian population using cone beam computed tomography (CBCT) and to analyze the anatomy of mandibular first molars with three roots through micro-CT. Material and Methods: CBCT images of 116 patients were reviewed to determine the prevalence of three-rooted first mandibular molars in a Brazilian subpopulation. Furthermore, with the use of micro-CT, 55 extracted three-rooted mandibular first molars were scanned and reconstructed to assess root length, distance between canal orifices, apical diameter, Vertucci's classification, presence of apical delta, number of foramina and furcations, lateral and accessory canals. The distance between the orifice on the pulp chamber floor and the beginning of the curvature and the angle of canal curvature were analyzed in the distolingual root. Data were compared using the Kruskal-Wallis test (α=0.05). Results: The prevalence of three-rooted mandibular first molars was of 2.58%. Mesial roots showed complex distribution of the root canal system in comparison to the distal roots. The median of major diameters of mesiobuccal, mesiolingual and single mesial canals were: 0.34, 0.41 and 0.60 mm, respectively. The higher values of major diameters were found in the distobuccal canals (0.56 mm) and the lower diameters in the distolingual canals (0.29 mm). The lowest orifice distance was found between the mesial canals (MB-ML) and the highest distance between the distal root canals (DB-DL). Almost all distal roots had one root canal and one apical foramen with few accessory canals. Conclusions: Distolingual root generally has short length, severe curvature and a single root canal with low apical diameter. PMID:27812625

The ability of Reciproc instruments to reach full working length without glide path preparation: a clinical retrospective study.

PubMed

Bartols, Andreas; Robra, Bernt-Peter; Walther, Winfried

2017-01-01

Reciproc instruments are the only contemporary root canal instruments where glide path preparation is no longer strictly demanded by the manufacturer. As the complete preparation of root canals is associated with success in endodontic treatment we wanted to assess the ability and find predictors for Reciproc instruments to reach full working length (RFWL) in root canals of maxillary molars in primary root canal treatment (1°RCTx) and retreatment (2°RCTx) cases. This retrospective study evaluated 255 endodontic treatment cases of maxillary molars. 180 were 1°RCTx and 75 2°RCTx. All root canals were prepared with Reciproc instruments. The groups were compared and in a binary logistic regression model predictors for RFWL were evaluated. A total of 926 root canals were treated with Reciproc without glide path preparation. This was possible in 885 canals (95.6%). In 1°RCTx cases 625 of 649 (96.3%) canals were RFWL and in 2°RCTx cases 260 of 277 (93.9%). In second and third mesiobuccal canals (MB2/3) 90 out of 101 (89.1%) were RFWL with Reciproc in 1°RCTx and in the 2°RCTx treatment group 49 out of 51 cases (96.1%). In mesio-buccal (MB1) canals "2°RCTx" was identified as negative predictor for RFWL (OR 0.24 (CI [0.08-0.77])). In MB2/3 canals full working length was reached less often (OR 0.04 (CI [0.01-0.31])) if the tooth was constricted and more often if MB2/3 and MB1 canals were convergent (OR 4.60 (CI [1.07-19.61])). Using Reciproc instruments, the vast majority of root canals in primary treatment and retreatment cases can be prepared without glide path preparation.

109. CEDAR DRAW SPILL, LOW LINE CANAL, TWIN FALLS COUNTY, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

109. CEDAR DRAW SPILL, LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF FILER, IDAHO; OVERALL VIEW LOOKING WEST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

95. CEDAR DRAW SPILL, LOW LINE CANAL, TWIN FALLS COUNTY ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

95. CEDAR DRAW SPILL, LOW LINE CANAL, TWIN FALLS COUNTY SOUTH OF FILER, IDAHO; OVERALL VIEW LOOKING EAST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

110. ROCK CREEK SIPHON, LOW LINE CANAL, TWIN FALLS COUNTY, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

110. ROCK CREEK SIPHON, LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; INLET SIDE WEST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

90. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

90. CEDAR DRAW SPILL, HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF FILER, IDAHO; CLOSE-UP OF GATES. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

112. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

112. ROCK CREEK SIPHON LOW LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY IDAHO; OUTLET SIDE, EAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

93. ROCK CREEK SIPHON, LOW LINE CANAL, TWIN FALLS COUNTY ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

93. ROCK CREEK SIPHON, LOW LINE CANAL, TWIN FALLS COUNTY SOUTH OF KIMBERLY, IDAHO; OVERALL NORTHEAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

147. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

147. TWIN FALLS MAIN CANAL DIVERSION, TWIN FALLS COUNTY, MILNER, IDAHO; VIEW OF MAIN HEADGATES, EAST VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

124. MCMULLEN CREEK HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

124. MCMULLEN CREEK HIGH LINE CANAL, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; OVERALL SOUTH VIEW OF DRAW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

188. Photocopy of drawing, Twin Falls Canal Company, date unknown. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

188. Photocopy of drawing, Twin Falls Canal Company, date unknown. DETAILS OF GATE RAISING MECHANISM, NO COUNTY; BLUEPRINT. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

3D Computer aided treatment planning in endodontics.

PubMed

van der Meer, Wicher J; Vissink, Arjan; Ng, Yuan Ling; Gulabivala, Kishor

2016-02-01

Obliteration of the root canal system due to accelerated dentinogenesis and dystrophic calcification can challenge the achievement of root canal treatment goals. This paper describes the application of 3D digital mapping technology for predictable navigation of obliterated canal systems during root canal treatment to avoid iatrogenic damage of the root. Digital endodontic treatment planning for anterior teeth with severely obliterated root canal systems was accomplished with the aid of computer software, based on cone beam computer tomography (CBCT) scans and intra-oral scans of the dentition. On the basis of these scans, endodontic guides were created for the planned treatment through digital designing and rapid prototyping fabrication. The custom-made guides allowed for an uncomplicated and predictable canal location and management. The method of digital designing and rapid prototyping of endodontic guides allows for reliable and predictable location of root canals of teeth with calcifically metamorphosed root canal systems. The endodontic directional guide facilitates difficult endodontic treatments at little additional cost. Copyright © 2016. Published by Elsevier Ltd.

Shaping ability of nickel-titanium rotary instruments in curved root canals.

PubMed

Talati, Ali; Moradi, Saeed; Forghani, Maryam; Monajemzadeh, Ali

2013-01-01

Disinfection and subsequent obturation of the root canal space require adequate mechanical enlargement of the canals. The purpose of this in vitro study was to compare the shaping ability of Mtwo, RaCe and Medin rotary instruments during the preparation of curved root canals. Sixty mesiobuccal root canals of mandibular molars with severe curvatures between 25-35(°) and radius of 4-9 mm were randomly divided into three groups of 20 canals each. Using pre- and post-instrumentation radiographs, straightening of the canal and the apical transportation were determined with AutoCAD software. The data were analyzed using Chi square, analysis of variance, and post-hoc tests and the significance level was set at P<0.05. Mtwo instruments maintained the canal curvature significantly better than Race and Medin instruments (P<0.05). There was significant difference between the rotary instruments for iatrogenic transportation of the major foramen (P>0.05). Under the conditions of this in vitro study, Mtwo instruments seemed superior to the two other rotary instruments.

Study of mastoid canals and grooves in north karnataka human skulls.

PubMed

Hadimani, Gavishiddappa Andanappa; Bagoji, Ishwar Basavantappa

2013-08-01

This study was undertaken to observe the frequency of mastoid canals and grooves in north Karnataka dry human skulls. 100 dry human skulls of unknown age and sex from the department of Anatomy were selected and observed for the present study. The mastoid regions of dry skulls were observed for the presence of mastoid canals and grooves, if any. A metallic wire was passed through the canal for its confirmation and then the length was measured. The Mastoid canals were present in 53% of the total 100 skulls observed either bilaterally or unilaterally. Mastoid grooves were present in 18% of the total skulls (100) observed. Double mastoid canal was found in 01% of total skull studied and both Mastoid canals & Mastoid grooves together were present in 02% of the total skulls (100) observed. The knowledge of mastoid canals and grooves is very important for otolaryngologists and neurosurgeons. Because they contain an arterial branch of occipital artery with its accompanying vein which is liable to injury resulting into severe bleeding.

Microbial profile of root canals of primary teeth with pulp necrosis and periradicular lesion.

PubMed

Triches, Thaisa Cezária; de Figueiredo, Luciene Cristina; Feres, Magda; de Freitas, Sérgio Fernando Torres; Zimmermann, Gláucia Santos; Cordeiro, Mabel Mariela Rodríguez

2014-01-01

The purpose of this study was to assess the microbial content of root canals of human primary teeth with pulp necrosis and periradicular lesion. Microbial samples were collected from 24 canals of children treated at a pediatric dentistry clinic. Microbiological identification was performed using checker-board DNA-DNA hybridization for 40 different bacteria. Data were analyzed per canal based on the mean count and frequency of each bacterial species. Detectable levels of bacterial species were observed for 35 probes (88%). The most frequent bacteria were Fusobacterium nucleatum sp. nucleatum, Fusobacterium periodonticum, Prevotella melaninogenica, Prevotella nigrescens, and Prevotella intermedia. Facultative species were identified in 20 root canals (83%), anaerobic species were identified in 24 root canals (100%), and aerobic species in 18 root canals (75%). Black-pigmented bacilli were found in 23 samples (96%). The number of different bacterial species detected per canal ranged from five to 33. Endodontic infection in primary teeth with pulp necrosis and periradicular lesion is multimicrobial, including aerobic, facultative, and anaerobic micro-organisms.

Anthropometry of external auditory canal by non-contactable measurement.

PubMed

Yu, Jen-Fang; Lee, Kun-Che; Wang, Ren-Hung; Chen, Yen-Sheng; Fan, Chun-Chieh; Peng, Ying-Chin; Tu, Tsung-Hsien; Chen, Ching-I; Lin, Kuei-Yi

2015-09-01

Human ear canals cannot be measured directly with existing general measurement tools. Furthermore, general non-contact optical methods can only conduct simple peripheral measurements of the auricle and cannot obtain the internal ear canal shape-related measurement data. Therefore, this study uses the computed tomography (CT) technology to measure the geometric shape of the ear canal and the shape of the ear canal using a non-invasive method, and to complete the anthropometry of external auditory canal. The results of the study show that the average height and width of ear canal openings, and the average depth of the first bend for men are generally longer, wider and deeper than those for women. In addition, the difference between the height and width of the ear canal opening is about 40% (p < 0.05). Hence, the circular cross-section shape of the earplugs should be replaced with an elliptical cross-section shape during manufacturing for better fitting. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Probing the correlation of neuronal loss, neurofibrillary tangles, and cell death markers across the Alzheimer's disease Braak stages: a quantitative study in humans.

PubMed

Theofilas, Panos; Ehrenberg, Alexander J; Nguy, Austin; Thackrey, Julia M; Dunlop, Sara; Mejia, Maria B; Alho, Ana T; Paraizo Leite, Renata Elaine; Rodriguez, Roberta Diehl; Suemoto, Claudia K; Nascimento, Camila F; Chin, Marcus; Medina-Cleghorn, Daniel; Cuervo, Ana Maria; Arkin, Michelle; Seeley, William W; Miller, Bruce L; Nitrini, Ricardo; Pasqualucci, Carlos Augusto; Filho, Wilson Jacob; Rueb, Udo; Neuhaus, John; Heinsen, Helmut; Grinberg, Lea T

2018-01-01

Clarifying the mechanisms connecting neurofibrillary tangle (NFT) neurotoxicity to neuronal dysfunction in humans is likely to be pivotal for developing effective treatments for Alzheimer's disease (AD). To model the temporal progression of AD in humans, we used a collection of brains with controls and individuals from each Braak stage to quantitatively investigate the correlation between intraneuronal caspase activation or macroautophagy markers, NFT burden, and neuronal loss, in the dorsal raphe nucleus and locus coeruleus, the earliest vulnerable areas to NFT accumulation. We fit linear regressions with each count as outcomes, with Braak score and age as the predictors. In progressive Braak stages, intraneuronal active caspase-6 positivity increases both alone and overlapping with NFTs. Likewise, the proportion of NFT-bearing neurons showing autophagosomes increases. Overall, caspases may be involved in upstream cascades in AD and are associated with higher NFTs. Macroautophagy changes correlate with increasing NFT burden from early AD stages. Copyright © 2017 Elsevier Inc. All rights reserved.

Research on the infiltration processes of lawn soils of the Babao River in the Qilian Mountain.

PubMed

Li, GuangWen; Feng, Qi; Zhang, FuPing; Cheng, AiFang

2014-01-01

Using a Guelph Permeameter, the soil water infiltration processes were analyzed in the Babao River of the Qilian Mountain in China. The results showed that the average soil initial infiltration and the steady infiltration rates in the upstream reaches of the Babao River are 1.93 and 0.99 cm/min, whereas those of the middle area are 0.48 cm/min and 0.21 cm/min, respectively. The infiltration processes can be divided into three stages: the rapidly changing stage (0-10 min), the slowly changing stage (10-30 min) and the stabilization stage (after 30 min). We used field data collected from lawn soils and evaluated the performances of the infiltration models of Philip, Kostiakov and Horton with the sum of squared error, the root mean square error, the coefficient of determination, the mean error, the model efficiency and Willmott's index of agreement. The results indicated that the Kostiakov model was most suitable for studying the infiltration process in the alpine lawn soils.

Root canal morphology and variations in mandibular second molar teeth of an Indian population: an in vivo cone-beam computed tomography analysis.

PubMed

Pawar, Ajinkya Mansing; Pawar, Mansing; Kfir, Anda; Singh, Shishir; Salve, Prashant; Thakur, Bhagyashree; Neelakantan, Prasanna

2017-12-01

This study aims to investigate the root canal morphology of permanent mandibular second molars of an Indian population in vivo using cone-beam computed tomography (CBCT) images. CBCT images (n = 983; males = 489, females = 494) of untreated, completely developed permanent mandibular second molar teeth were examined. CBCT scans were acquired as part of diagnosis and treatment planning for treatments unrelated to the present study. The number of roots and root canals were recorded. Canal configuration was classified based on Vertucci's and Fan's classifications. The most common configuration was two-root (79.35%) and three-root canals (53.50%). The incidence of three-rooted molars was 7.53%, whereas 13.12% of the studied teeth studied have fused roots with C-shaped canals. The predominant canal morphology in the mesial roots was Vertucci's type IV (45.17%), followed by type II (32.55%), type I (7.23%), type V (1.02%), and type III (0.91%). The distal root in contrast showed type I (61.14%) as the predominant canal configuration, followed by type II (18.21%) and type IV (7.53%). The incidence of three-rooted molars was higher in males (n = 55; 5.59%) than in females (n = 19; 1.94%) (p < 0.01). The canals in the extra roots exhibited type I (100%) root canal morphology. In teeth with C-shaped root canal (13.12%), the variations in the coronal, middle, and apical third ranged from C1 to C4. Root canal systems of the mesial roots of mandibular second molars of the study population demonstrated a high degree of variability. While three roots were rare, there was a sexual predisposition. Fused roots with C-shaped canals were rare and demonstrated significant variations from the coronal to apical third. Root canal morphology can demonstrate variations based on race and sex of patients. Clinicians must always consider the possible variations to ensure successful endodontic treatment.

Endodontic photodynamic therapy ex vivo.

PubMed

Ng, Raymond; Singh, Fiza; Papamanou, Despina A; Song, Xiaoqing; Patel, Chitrang; Holewa, Colleen; Patel, Niraj; Klepac-Ceraj, Vanja; Fontana, Carla R; Kent, Ralph; Pagonis, Tom C; Stashenko, Philip P; Soukos, Nikolaos S

2011-02-01

The objective of this study was to evaluate the antimicrobial effects of photodynamic therapy (PDT) on infected human teeth ex vivo. Fifty-two freshly extracted teeth with pulpal necrosis and associated periradicular radiolucencies were obtained from 34 subjects. Twenty-six teeth with 49 canals received chemomechanical debridement (CMD) with 6% NaOCl, and 26 teeth with 52 canals received CMD plus PDT. For PDT, root canal systems were incubated with methylene blue (MB) at concentration of 50 μg/mL for 5 minutes, followed by exposure to red light at 665 nm with an energy fluence of 30 J/cm(2). The contents of root canals were sampled by flushing the canals at baseline and after CMD alone or CMD+PDT and were serially diluted and cultured on blood agar. Survival fractions were calculated by counting colony-forming units (CFUs). Partial characterization of root canal species at baseline and after CMD alone or CMD+PDT was performed by using DNA probes to a panel of 39 endodontic species in the checkerboard assay. The Mantel-Haenszel χ(2) test for treatment effects demonstrated the better performance of CMD+PDT over CMD (P = .026). CMD+PDT significantly reduced the frequency of positive canals relative to CMD alone (P = .0003). After CMD+PDT, 45 of 52 canals (86.5%) had no CFUs as compared with 24 of 49 canals (49%) treated with CMD (canal flush samples). The CFU reductions were similar when teeth or canals were treated as independent entities. Post-treatment detection levels for all species were markedly lower for canals treated by CMD+PDT than they were for those treated by CMD alone. Bacterial species within dentinal tubules were detected in 17 of 22 (77.3%) and 15 of 29 (51.7%) canals in the CMD and CMD+PDT groups, respectively (P = .034). Data indicate that PDT significantly reduces residual bacteria within the root canal system, and that PDT, if further enhanced by technical improvements, holds substantial promise as an adjunct to CMD. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Earth Observations taken by the Expedition 18 Crew

NASA Image and Video Library

2009-01-31

ISS018-E-024949 (31 Jan. 2009) --- The All-American Canal, the largest irrigation canal in the world and a key landmark along the California-Mexico border, is featured in this image photographed by an Expedition 18 crewmember on the International Space Station. This image captures about 15 kilometers of the important infrastructure corridor just west of Yuma, AZ. The prominent dark line crossing the image is the Canal which is crossed, in this view, by Interstate Highway 8. The canal carries 740.6 cubic meters (26,155 cubic feet) of water per second from the Colorado River westward to support the intensive agriculture of California?s Imperial Valley to the northwest, and to nine cities including San Diego, CA. The canal system is the Imperial Valley?s only source of water, and allows irrigation of more than 2,000 square kilometers (500,000 acres) of agricultural fields. The Coachella Canal, one of four main branch canals, leads water north to Imperial Valley. This section of the canal requires constant maintenance. Approximately 68,000 acre-feet of water per year are lost by seepage from the All-American Canal - especially where the canal crosses the great Algodones Dune Field, a portion of which is visible extending from top to bottom in the center of the image. Additionally, dune sand is constantly blown to the southeast, and into the canal. As part of California?s Colorado River Water Use Plan, 37 kilometers (23 miles) of the canal is being lined to prevent water loss by seepage. A recently opened sector parallels the old canal (right) and new lined sectors are under construction (bright lines, center). Engineers have sited new sections of the canal to avoid the worst areas of dune-sand invasion, so that the new configuration will be significantly cheaper to maintain and operate. A new road crosses the dunes and marks the US?Mexico border as part of border fence construction efforts. The margin of the Colorado River floodplain in Mexico is just visible two kilometers south of the border (lower left corner). This floodplain is Mexico?s equivalent of the Imperial Valley in terms of its enormous irrigated agricultural production.

Efficacy of ultrasonic activation of NaOCl and orange oil in removing filling material from mesial canals of mandibular molars with and without isthmus

PubMed Central

Barreto, Mirela Sangoi; da Rosa, Ricardo Abreu; Santini, Manuela Favarin; Cavenago, Bruno Cavalini; Duarte, Marco Antônio Húngaro; Bier, Carlos Alexandre Souza; Só, Marcos Vinícius Reis

2016-01-01

ABSTRACT Objectives The aim of this study was to evaluate the volume of remaining filling material after passive ultrasonic irrigation (PUI) of sodium hypochlorite (NaOCl) and orange oil in mesial canals of mandibular molars, with and without isthmus. Material and Methods Thirty mesial roots of mandibular molars were divided according to the presence or absence of isthmus. Canals were prepared and filled (Micro-CT #1). Filling was removed using rotary instruments, and specimens were sub-divided into three groups according to the irrigation procedures: Conventional – conventional irrigation with NaOCl, PUI/NaOCl – PUI of NaOCl (three activations, 20 seconds each), and PUI/orange oil – PUI of orange oil (Micro-CT#2). Specimens were enlarged using the X2 and X3 ProTaper Next instruments and submitted to the same irrigation protocols (Micro-CT #3). Results No differences were found between the experimental groups in each stage of assessment (P>0.05). The volume of residual filling material was similar to those in Micro-CT #2 and Micro-CT #3, but lower than those observed in Micro-CT #1 (P<0.05). When groups were pooled according to the presence or absence of an isthmus, volume of residual filling material was higher in specimens presenting isthmus (P<0.05). Conclusions PUI of NaOCl or orange oil did not improve filling removal. Isthmus consists in an anatomical obstacle that impairs the removal of filling material. PMID:26200525

The success rate of bupivacaine and lidocaine as anesthetic agents in inferior alveolar nerve block in teeth with irreversible pulpitis without spontaneous pain

PubMed Central

Yosefi, Mohammad Hosein; Nakhaee, Nouzar

2015-01-01

Objectives Achieving adequate anesthesia with inferior alveolar nerve blocks (IANB) is of great importance during dental procedures. The aim of the present study was to assess the success rate of two anesthetic agents (bupivacaine and lidocaine) for IANB when treating teeth with irreversible pulpitis. Materials and Methods Sixty volunteer male and female patients who required root canal treatment of a mandibular molar due to caries participated in the present study. The inclusion criteria included prolonged pain to thermal stimulus but no spontaneous pain. The patients were randomly allocated to receive either 2% lidocaine with 1:80,000 epinephrine or 0.5% bupivacaine with 1:200,000 epinephrine as an IANB injection. The sensitivity of the teeth to a cold test as well as the amount of pain during access cavity preparation and root canal instrumentation were recorded. Results were statistically analyzed with the Chi-Square and Fischer's exact tests. Results At the final step, fifty-nine patients were included in the study. The success rate for bupivacaine and lidocaine groups were 20.0% and 24.1%, respectively. There was no significant difference between the two groups at any stage of the treatment procedure. Conclusions There was no difference in success rates of anesthesia when bupivacaine and lidocaine were used for IANB injections to treat mandibular molar teeth with irreversible pulpitis. Neither agent was able to completely anesthetize the teeth effectively. Therefore, practitioners should be prepared to administer supplemental anesthesia to overcome pain during root canal treatment. PMID:25984478

The life history of Pleurogenoides malampuzhensis sp. nov. (Digenea: Pleurogenidae) from amphibious and aquatic hosts in Kerala, India.

PubMed

Brinesh, R; Janardanan, K P

2014-06-01

The life-cycle stages of Pleurogenoides malampuzhensis sp. nov. infecting the Indian bullfrog Hoplobatrachus tigerinus (Daudin) and the skipper frog Euphlyctis cyanophlyctis (Schneider) occurring in irrigation canals and paddy fields in Malampuzha, which forms part of the district of Palakkad, Kerala, are described. The species is described, its systematic position discussed and compared with the related species, P. gastroporus (Luhe, 1901) and P. orientalis (Srivastava, 1934). The life-cycle stages, from cercaria to egg-producing adult, were successfully established in the laboratory. Virgulate xiphidiocercariae emerged from the snail Digoniostoma pulchella (Benson). Metacercariae are found in muscle tissues of dragonfly nymphs and become infective to the frogs within 22 days. The pre-patent period is 20 days. Growth and development of both metacercariae and adults are described.

Novel navigation technique for the endodontic treatment of a molar with pulp canal calcification and apical pathology.

PubMed

Shi, Xilin; Zhao, Shiyong; Wang, Weidong; Jiang, Qianzhou; Yang, Xuechao

2018-04-01

Apical periodontitis, the inflammation of periapical tissue, commonly requires root canal treatment to achieve apical healing. However, if it is accompanied by pulp canal calcification, the treatment becomes complicated, and locating the root canal can be challenging. This case report describes a novel approach for treating a molar with pulp canal calcification and apical pathology. Due to the risk of perforation during treatment, a digitally printed template was used to assist in accurately locating the root canal. After six months, the patient was asymptomatic and the periradicular radiolucency was gradually reducing in size. © 2017 Australian Society of Endodontology Inc.

Unusual Root Canal Irrigation Solutions.

PubMed

Mohammadi, Zahed; Jafarzadeh, Hamid; Shalavi, Sousan; Kinoshita, Jun-Ichiro

2017-05-01

Microorganisms and their by-products play a critical role in pulp and periradicular pathosis. Therefore, one of the main purposes of root canal treatment is disinfection of the entire system of the canal. This aim may be obtained using mechanical preparation, chemical irrigation, and temporary medication of the canal. For this purpose, various irrigation solutions have been advocated. Common root canal irrigants, such as sodium hypochlorite, chlorhexidine, and a mixture of tetracycline, acid, and detergent have been extensively reviewed. The aim of this review was to address the less common newer root canal irrigation solutions, such as citric acid, maleic acid, electrochemically activated water, green tea, ozonated water, and SmearClear.

Bilateral presence of two root canals in maxillary central incisors: A rare case study.

PubMed

Kavitha, M; Gokul, Kannan; Ramaprabha, B; Lakshmi, Amudha

2014-04-01

Success in root canal treatment is achieved after thorough cleaning and shaping followed by complete obturation of the canal system. Therefore, endodontic therapy requires specific and complete knowledge of the internal and external dental anatomy, and its variations in presentation. The internal anatomy of the maxillary central incisor is well-known and usually presents one root canal system. This case report describes an endodontic treatment of traumatized both maxillary central incisors with two canal systems. Knowledge of dental anatomy is fundamental for proper endodontic practice. When root canal treatment is performed, the clinician should be aware that both external and internal anatomy may be abnormal.

Maxillary First Molars with 2 Distobuccal Canals: A Case Series.

PubMed

Fogel, Howard M; Cunha, Rodrigo Sanches

2017-11-01

An appreciation of the anatomic complexity of the root canal system is essential at every step of endodontic treatment. Endodontic treatment of teeth with unusual root canal anatomy presents a unique challenge. Eight patients underwent nonsurgical root canal treatment of 3-rooted maxillary first molars in a specialty endodontic private practice. Four cases of Weine type II and 4 cases of Weine type III canal configurations in the distobuccal root of maxillary first molars were presented.This article highlighted an uncommon anatomic variation of 2 canals in the distobuccal root of the maxillary first molar. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Root and canal morphology of mandibular third molars in an Iranian population.

PubMed

Kuzekanani, Maryam; Haghani, Jahangir; Nosrati, Hossein

2012-01-01

A through knowledge of the root canal morphology is required for successful endodontic ther-apy. The aim of this study was to investigate the root and canal morphology of mandibular third molars in Kerman, a prov-ince in southeast of Iran. One-hundred-fifty extracted mandibular third molars were collected randomly from different dental clinics in Kerman. The root canal anatomy and morphology of each tooth was carefully studied using a clearing tech-nique. Root number and morphology, number of canals per root, root canal configuration according to Vertucci classifica-tion, and incidence of dilacerated roots and C-shaped canals in mandibular third molars were evaluated under stereomicro-scope with ×2 to ×3 magnifications. From the total of 150 mandibular third molars studied, 21% had one root. The majority of teeth (73%) had two roots. 5.5% of the teeth had three roots. The incidence of C-shaped canal was 3.5% in this study and 8% of the teeth had at least one dilacerated root. Although root canal anatomy and morphology of mandibular third molars is very variable having two roots seems to be the normal anatomy for these teeth.

Eye size and visual acuity influence vestibular anatomy in mammals.

PubMed

Kemp, Addison D; Christopher Kirk, E

2014-04-01

The semicircular canals of the inner ear detect head rotations and trigger compensatory movements that stabilize gaze and help maintain visual fixation. Mammals with large eyes and high visual acuity require precise gaze stabilization mechanisms because they experience diminished visual functionality at low thresholds of uncompensated motion. Because semicircular canal radius of curvature is a primary determinant of canal sensitivity, species with large canal radii are expected to be capable of more precise gaze stabilization than species with small canal radii. Here, we examine the relationship between mean semicircular canal radius of curvature, eye size, and visual acuity in a large sample of mammals. Our results demonstrate that eye size and visual acuity both explain a significant proportion of the variance in mean canal radius of curvature after statistically controlling for the effects of body mass and phylogeny. These findings suggest that variation in mean semicircular canal radius of curvature among mammals is partly the result of selection for improved gaze stabilization in species with large eyes and acute vision. Our results also provide a possible functional explanation for the small semicircular canal radii of fossorial mammals and plesiadapiforms. Copyright © 2014 Wiley Periodicals, Inc.

Definition and endodontic treatment of dilacerated canals: a survey of Diplomates of the American Board of Endodontics.

PubMed

Dastmalchi, Nafiseh; Kazemi, Zeinab; Hashemi, Siroos; Peters, Ove A; Jafarzadeh, Hamid

2011-01-01

To gather data from Diplomates of the American Board of Endodontics regarding treatment of dilacerated canals. A questionnaire addressing definition, endodontic treatment procedures and prognosis was constructed and distributed via e-mail to 708 Diplomates of the American Board of Endodontics. Data from 150 respondents, a 21% response rate, were collected by using a Web-based interface. For statistical analysis, Chi-square tests were used. More than 25% of respondents believed that a dilacerated root should have a curvature > 40°. One-visit treatment is the best therapeutic approach and transportation is the most likely complication in preparation of these canals. A crown-down technique, watch-winding motion and a master apical file # 25 are the best choices for preparation of these canals. Any warm obturation technique is preferred over lateral compaction by most respondents. A crown-down technique for root canal preparation and a thermoplastic obturation technique are recommended for canals whose curvature is more than 40°. The prognosis of the treatment of these canals is judged not lower than normal canals. Crown-down technique and thermoplastic obturation are recommended for dilacerated canals.

Evaluation of the root and canal morphology of mandibular permanent molars in a south-eastern Turkish population using cone-beam computed tomography

PubMed Central

Nur, Bilge Gulsum; Ok, Evren; Altunsoy, Mustafa; Aglarci, Osman Sami; Colak, Mehmet; Gungor, Enes

2014-01-01

Objective: The aim of this retrospective study was to determine the root and canal morphology of the mandibular first and second permanent molars in a Turkish population using cone-beam computed tomography (CBCT). Materials and Methods: CBCT images of mandibular first (n = 966) and second molar (n = 1165) teeth from 850 Turkish patients were evaluated. The root canal configurations were classified according to the method of Vertucci. The data were analyzed by Pearson's Chi-square test. Results: The majority of mandibular molars were two rooted with three canals; however, three roots were identified in 0.05% of the first molars and 0.01% of the second molars, and 100% of the additional root canals were of type I configuration. Mesial roots had more complex canal systems with more than one canal, whereas most distal roots had a type I configuration. Conclusions: Within the limitations of this study, it can be concluded that CBCT scanning provides supplemental information about the root canal configurations of mandibular molars in a Turkish population. This study may help clinicians in the root canal treatment of mandibular molars. PMID:24966763

Effect of finishing instrumentation using NiTi hand files on volume, surface area and uninstrumented surfaces in C-shaped root canal systems.

PubMed

Amoroso-Silva, P; Alcalde, M P; Hungaro Duarte, M A; De-Deus, G; Ordinola-Zapata, R; Freire, L G; Cavenago, B C; De Moraes, I G

2017-06-01

To assess the effect of 90°-oscillatory instrumentation with hand files on several morphological parameters (volume, surface area and uninstrumented surface) in C-shaped root canals after instrumentation using a single-file reciprocation system (Reciproc; VDW, Munich, Germany) and a Self-Adjusting File System (SAF; ReDent Nova, Ra'anana, Israel). Twenty mandibular second molars with C-shaped canals and C1 canal configurations were divided into two groups (n = 10) and instrumented with Reciproc and SAF instruments. A size 30 NiTi hand K-file attached to a 90°-oscillatory motion handpiece was used as final instrumentation in both groups. The specimens were scanned using micro-computed tomography after all procedures. Volume, surface area increase and uninstrumented root canal surface were analysed using CTAn software (Bruker-microCT, Kontich, Belgium). Also, the uninstrumented root canal surface was calculated for each canal third. All values were compared between groups using the Mann-Whitney test and within groups using the Wilcoxon's signed-rank test. Instrumentation with Reciproc significantly increased canal volume compared with instrumentation with SAF. Additionally, the canal volumes were significantly increased after 90°-oscillatory instrumentation (between and within group comparison; (P < 0.05)). Regarding the increase in surface area after all instrumentation protocols, statistical analysis only revealed significant differences in the within groups comparison (P < 0.05). Reciproc and SAF instrumentation yielded an uninstrumented root canal surface of 28% and 34%, respectively, which was not significantly different (P > 0.05). Final oscillatory instrumentation significantly reduced the uninstrumented root canal surface from 28% to 9% (Reciproc) and from 34% to 15% (SAF; P < 0.05). The apical and middle thirds exhibited larger uninstrumented root canal surfaces after the first instrumentation that was significantly reduced after oscillatory instrumentation (P < 0.05). The Reciproc and SAF system were associated with similar morphological parameters after instrumentation of mandibular second molars with C-shaped canals except for a higher canal volume increase in the Reciproc group compared to the SAF. Furthermore, the final use of 90°-oscillatory instrumentation using NiTi hand files significantly decreased the uninstrumented canal walls that remained after Reciproc and SAF instrumentation. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.