The effect of deer management on the abundance of Ixodes ricinus in Scotland.

PubMed

Gilbert, L; Maffey, G L; Ramsay, S L; Hester, A J

2012-03-01

The management of wildlife hosts for controlling parasites and disease has a history of mixed success. Deer can be important hosts for ticks, such as Ixodes ricinus, which is the primary vector of disease-causing zoonotic pathogens in Europe. Deer are generally managed by culling and fencing for forestry protection, habitat conservation, and commercial hunting, and in this study we test whether these deer management methods can be useful for controlling ticks, with implications for tick-borne pathogens. At different spatial scales and habitats we tested the hypotheses that tick abundance is reduced by (1) culling deer and (2) deer exclusion using fencing. We compared abundance indices of hosts and questing I. ricinus nymphs using a combination of small-scale fencing experiments on moorland, a large-scale natural experiment of fenced and unfenced pairs of forests, and cross-sectional surveys of forest and moorland areas with varying deer densities. As predicted, areas with fewer deer had fewer ticks, and fenced exclosures had dramatically fewer ticks in both large-scale forest and small-scale moorland plots. Fencing and reducing deer density were also associated with higher ground vegetation. The implications of these results on other hosts, pathogen prevalence, and disease risk are discussed. This study provides evidence of how traditional management methods of a keystone species can reduce a generalist parasite, with implications for disease risk mitigation.

Comparing Habitat Suitability and Connectivity Modeling Methods for Conserving Pronghorn Migrations

PubMed Central

Poor, Erin E.; Loucks, Colby; Jakes, Andrew; Urban, Dean L.

2012-01-01

Terrestrial long-distance migrations are declining globally: in North America, nearly 75% have been lost. Yet there has been limited research comparing habitat suitability and connectivity models to identify migration corridors across increasingly fragmented landscapes. Here we use pronghorn (Antilocapra americana) migrations in prairie habitat to compare two types of models that identify habitat suitability: maximum entropy (Maxent) and expert-based (Analytic Hierarchy Process). We used distance to wells, distance to water, NDVI, land cover, distance to roads, terrain shape and fence presence to parameterize the models. We then used the output of these models as cost surfaces to compare two common connectivity models, least-cost modeling (LCM) and circuit theory. Using pronghorn movement data from spring and fall migrations, we identified potential migration corridors by combining each habitat suitability model with each connectivity model. The best performing model combination was Maxent with LCM corridors across both seasons. Maxent out-performed expert-based habitat suitability models for both spring and fall migrations. However, expert-based corridors can perform relatively well and are a cost-effective alternative if species location data are unavailable. Corridors created using LCM out-performed circuit theory, as measured by the number of pronghorn GPS locations present within the corridors. We suggest the use of a tiered approach using different corridor widths for prioritizing conservation and mitigation actions, such as fence removal or conservation easements. PMID:23166656

Comparing habitat suitability and connectivity modeling methods for conserving pronghorn migrations.

PubMed

Poor, Erin E; Loucks, Colby; Jakes, Andrew; Urban, Dean L

2012-01-01

Terrestrial long-distance migrations are declining globally: in North America, nearly 75% have been lost. Yet there has been limited research comparing habitat suitability and connectivity models to identify migration corridors across increasingly fragmented landscapes. Here we use pronghorn (Antilocapra americana) migrations in prairie habitat to compare two types of models that identify habitat suitability: maximum entropy (Maxent) and expert-based (Analytic Hierarchy Process). We used distance to wells, distance to water, NDVI, land cover, distance to roads, terrain shape and fence presence to parameterize the models. We then used the output of these models as cost surfaces to compare two common connectivity models, least-cost modeling (LCM) and circuit theory. Using pronghorn movement data from spring and fall migrations, we identified potential migration corridors by combining each habitat suitability model with each connectivity model. The best performing model combination was Maxent with LCM corridors across both seasons. Maxent out-performed expert-based habitat suitability models for both spring and fall migrations. However, expert-based corridors can perform relatively well and are a cost-effective alternative if species location data are unavailable. Corridors created using LCM out-performed circuit theory, as measured by the number of pronghorn GPS locations present within the corridors. We suggest the use of a tiered approach using different corridor widths for prioritizing conservation and mitigation actions, such as fence removal or conservation easements.

Use of remote sensing techniques to determine the effects of grazing on vegetation cover and dune elevation at assateague island national seashore: Impact of horses

USGS Publications Warehouse

De Stoppelaire, G. H.; Gillespie, T.W.; Brock, J.C.; Tobin, G.A.

2004-01-01

The effects of grazing by feral horses on vegetation and dune topography at Assateague Island National Seashore were investigated using color-infrared imagery, lidar surveys, and field measurements. Five pairs of fenced and unfenced plots (300 m2) established in 1993 on sand flats and small dunes with similar elevation, topography, and vegetation cover were used for this study. Color-infrared imagery from 1998 and field measurements from 2001 indicated that there was a significant difference in vegetation cover between the fenced and unfenced plot-pairs over the study period. Fenced plots contained a higher percentage of vegetation cover that was dominated by American beachgrass (Ammophila breviligulata). Lidar surveys from 1997, 1999, and 2000 showed that there were significant differences in elevation and topography between fenced and unfenced plot-pairs. Fenced plots were, on average, 0.63 m higher than unfenced plots, whereas unfenced plots had generally decreased in elevation after establishment in 1993. Results demonstrate that feral horse grazing has had a significant impact on dune formation and has contributed to the erosion of dunes at Assateague Island. The findings suggest that unless the size of the feral horse population is reduced, grazing will continue to foster unnaturally high rates of dune erosion into the future. In order to maintain the natural processes that historically occurred on barrier islands, much larger fenced exclosures would be required to prevent horse grazing. ?? 2004 Springer Science+Business Media, Inc.

Monitoring surface albedo change with Landsat

NASA Technical Reports Server (NTRS)

Otterman, J.

1977-01-01

A pronounced decrease of the surface albedo (reflectivity) has been observed in an area in the Northern Sinai, fenced-in in the summer of 1974. Analysis of the Landsat Multispectral Scanner System digital data from an April 1977 pass indicates a reduction in the albedo in the exclosure by 13%, as compared to the outside, which continues to be subjected to overgrazing and anthropogenic pressures. The reduction of reflectivity is approximately the same in all the spectral bands, and is therefore attributable to accumulation of dead plants and plant debris, and not directly to live vegetation.

An experimental test of whether habitat corridors affect pollen transfer.

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

Townsend, Patricia A.; Levey, Douglas J.

Abstract. Negative effects of habitat fragmentation are thought to be diminished when habitat patches are joined by a corridor. A key assumption is that corridors facilitate exchange rates of organisms between otherwise isolated patches. If the organisms are pollinators, corridors may be important for maintaining genetically viable populations of the plants that they pollinate. We tested the hypothesis that corridors increase the movement of insect pollinators into patches of habitat and thereby increase pollen transfer for two species of plants, one pollinated by butterflies (Lantana camara) and the other by bees and wasps (Rudbeckia hirta). We worked in an experimentalmore » landscape consisting of 40 greater than or equal to 1-ha patches of early-successional habitat in a matrix of forest. Within each of eight experimental units, two patches were connected by a corridor (150 X 25 m), and three were not. Patch shape varied to control for the area added by the presence of a corridor. Differences in patch shape also allowed us to test alternative hypotheses of how corridors might function. The Traditional Corridor Hypothesis posits that corridors increase immigration and emigration by functioning as movement conduits between patches. The Drift Fence Hypothesis posits that corridors function by ‘‘capturing’’ organisms dispersing through the matrix, redirecting them into associated habitat patches. Using fluorescent powder to track pollen, we found that pollen transfer by butterflies between patches connected by a corridor was significantly higher than between unconnected patches (all values mean plus or minus 1 SE: 59% plus or minus 9.2% vs. 25% plus or minus 5.2% of flowers receiving pollen). Likewise, pollen transfer by bees and wasps was significantly higher between connected patches than between unconnected patches (30% plus or minus 4.2% vs. 14.5% plus or minus 2.2%). These results support the Traditional Corridor Hypothesis. There was little support, however, for the Drift Fence Hypothesis. To generalize our results to a larger scale, we measured the probability of pollen transfer by butterflies as a function of distance along a 2000 X 75 m corridor. Pollen transfer probability exponentially declined with respect to distance and successfully predicted pollen transfer probability on the scale of our previous experiment. These results suggest that corridors facilitate pollen transfer in fragmented landscapes.« less

Bozeman Pass post-fencing wildlife monitoring.

DOT National Transportation Integrated Search

2010-12-01

The Bozeman Pass transportation corridor between Bozeman and Livingston, Montana, includes Interstate 90 (I-90), frontage roads, : and a railroad. The highway was a suspected barrier and hazard to animal movement in the Bozeman Pass area, which is co...

Ungulate browsers promote herbaceous layer diversity in logged temperate forests

USGS Publications Warehouse

Faison, Edward K.; DeStefano, Stephen; Foster, David R.; Motzkin, Glenn; Rapp, Josh

2016-01-01

Ungulates are leading drivers of plant communities worldwide, with impacts linked to animal density, disturbance and vegetation structure, and site productivity. Many ecosystems have more than one ungulate species; however, few studies have specifically examined the combined effects of two or more species on plant communities. We examined the extent to which two ungulate browsers (moose [Alces americanus]) and white-tailed deer [Odocoileus virginianus]) have additive (compounding) or compensatory (opposing) effects on herbaceous layer composition and diversity, 5–6 years after timber harvest in Massachusetts, USA. We established three combinations of ungulates using two types of fenced exclosures – none (full exclosure), deer (partial exclosure), and deer + moose (control) in six replicated blocks. Species composition diverged among browser treatments, and changes were generally additive. Plant assemblages characteristic of closed canopy forests were less abundant and assemblages characteristic of open/disturbed habitats were more abundant in deer + moose plots compared with ungulate excluded areas. Browsing by deer + moose resulted in greater herbaceous species richness at the plot scale (169 m2) and greater woody species richness at the subplot scale (1 m2) than ungulate exclusion and deer alone. Browsing by deer + moose resulted in strong changes to the composition, structure, and diversity of forest herbaceous layers, relative to areas free of ungulates and areas browed by white-tailed deer alone. Our results provide evidence that moderate browsing in forest openings can promote both herbaceous and woody plant diversity. These results are consistent with the classic grazing-species richness curve, but have rarely been documented in forests.

Deer presence rather than abundance determines the population density of the sheep tick, Ixodes ricinus, in Dutch forests.

PubMed

Hofmeester, Tim R; Sprong, Hein; Jansen, Patrick A; Prins, Herbert H T; van Wieren, Sipke E

2017-09-19

Understanding which factors drive population densities of disease vectors is an important step in assessing disease risk. We tested the hypothesis that the density of ticks from the Ixodes ricinus complex, which are important vectors for tick-borne diseases, is determined by the density of deer, as adults of these ticks mainly feed on deer. We performed a cross-sectional study to investigate I. ricinus density across 20 forest plots in the Netherlands that ranged widely in deer availability to ticks, and performed a deer-exclosure experiment in four pairs of 1 ha forest plots in a separate site. Ixodes ricinus from all stages were more abundant in plots with deer (n = 17) than in plots without deer (n = 3). Where deer were present, the density of ticks did not increase with the abundance of deer. Experimental exclosure of deer reduced nymph density by 66% and adult density by 32% within a timeframe of two years. In this study, deer presence rather than abundance explained the density of I. ricinus. This is in contrast to previous studies and might be related to the relatively high host-species richness in Dutch forests. This means that reduction of the risk of acquiring a tick bite would require the complete elimination of deer in species rich forests. The fact that small exclosures (< 1 ha) substantially reduced I. ricinus densities suggests that fencing can be used to reduce tick-borne disease risk in areas with high recreational pressure.

Herbivory and Competition of Tibetan Steppe Vegetation in Winter Pasture: Effects of Livestock Exclosure and Plateau Pika Reduction

PubMed Central

Harris, Richard B.; Wenying, Wang; Badinqiuying; Smith, Andrew T.

2015-01-01

Rangeland degradation has been identified as a serious concern in alpine regions of western China on the Qinghai-Tibetan plateau (QTP). Numerous government-sponsored programs have been initiated, including many that feature long-term grazing prohibitions and some that call for eliminating pastoralism altogether. As well, government programs have long favored eliminating plateau pikas (Ochotona curzoniae), assumed to contribute to degraded conditions. However, vegetation on the QTP evolved in the presence of herbivory, suggesting that deleterious effects from grazing are, to some extent, compensated for by reduced plant-plant competition. We examined the dynamics of common steppe ecosystem species as well as physical indicators of rangeland stress by excluding livestock and reducing pika abundance on experimental plots, and following responses for 4 years. We established 12 fenced livestock exclosures within pastures grazed during winter by local pastoralists, and removed pikas on half of these. We established paired, permanent vegetation plots within and outside exclosures and measured indices of erosion and biomass of common plant species. We observed modest restoration of physical site conditions (reduced bare soil, erosion, greater vegetation cover) with both livestock exclusion and pika reduction. As expected in areas protected from grazing, we observed a reduction in annual productivity of plant species avoided by livestock and assumed to compete poorly when protected from grazing. Contrary to expectation, we observed similar reductions in annual productivity among palatable, perennial graminoids under livestock exclusion. The dominant grass, Stipa purpurea, displayed evidence of density-dependent growth, suggesting that intra-specific competition exerted a regulatory effect on annual production in the absence of grazing. Complete grazing bans on winter pastures in steppe habitats on the QTP may assist in the recovery of highly eroded pastures, but may not increase annual vegetative production. PMID:26208005

Herbivory and Competition of Tibetan Steppe Vegetation in Winter Pasture: Effects of Livestock Exclosure and Plateau Pika Reduction.

PubMed

Harris, Richard B; Wenying, Wang; Badinqiuying; Smith, Andrew T; Bedunah, Donald J

2015-01-01

Rangeland degradation has been identified as a serious concern in alpine regions of western China on the Qinghai-Tibetan plateau (QTP). Numerous government-sponsored programs have been initiated, including many that feature long-term grazing prohibitions and some that call for eliminating pastoralism altogether. As well, government programs have long favored eliminating plateau pikas (Ochotona curzoniae), assumed to contribute to degraded conditions. However, vegetation on the QTP evolved in the presence of herbivory, suggesting that deleterious effects from grazing are, to some extent, compensated for by reduced plant-plant competition. We examined the dynamics of common steppe ecosystem species as well as physical indicators of rangeland stress by excluding livestock and reducing pika abundance on experimental plots, and following responses for 4 years. We established 12 fenced livestock exclosures within pastures grazed during winter by local pastoralists, and removed pikas on half of these. We established paired, permanent vegetation plots within and outside exclosures and measured indices of erosion and biomass of common plant species. We observed modest restoration of physical site conditions (reduced bare soil, erosion, greater vegetation cover) with both livestock exclusion and pika reduction. As expected in areas protected from grazing, we observed a reduction in annual productivity of plant species avoided by livestock and assumed to compete poorly when protected from grazing. Contrary to expectation, we observed similar reductions in annual productivity among palatable, perennial graminoids under livestock exclusion. The dominant grass, Stipa purpurea, displayed evidence of density-dependent growth, suggesting that intra-specific competition exerted a regulatory effect on annual production in the absence of grazing. Complete grazing bans on winter pastures in steppe habitats on the QTP may assist in the recovery of highly eroded pastures, but may not increase annual vegetative production.

Vegetation response of a dry shrubland community to feral goat management on the island of Moloka‘i, Hawai‘i

USGS Publications Warehouse

Jacobi, James D.; Stock, Jonathan

2017-12-14

The Hawaiian Islands are well known for their unique ecosystem assemblages that have a high proportion of endemic flora and fauna. However, since human colonization of this archipelago—starting with the arrival of Polynesian sailors approximately 1,200 years ago, and particularly following western contact in 1778—thousands of non-native species have been introduced to the Islands and many of these alien species have had severe impacts on the native ecosystems. Particularly damaging to these ecosystems are large mammals, including goats (Capra hircus), pigs (Sus scrofa), cattle (Bos taurus), deer (Axis axis and Odocoileus hemionus), and sheep (Ovis spp.), which are collectively referred to here as ungulates; they cause extensive damage to the native vegetation by their browsing, grazing, and trampling. Similar impacts have been documented elsewhere, including New Zealand and many other island ecosystems.Previous studies in Hawai‘i have utilized fenced exclosures to assess the impacts of feral or wild ungulates on vegetation and the recovery potential for the native plant communities by comparing plant community composition, structure, and cover inside the fenced area (without ungulates) over time to the vegetation condition outside of the protection of the fence. In some cases, the native vegetation recovered once the animals were removed. However, in other situations alien plants were more competitive and dominated the revegetation process after the impacts of ungulates had been reduced or eliminated.This report describes the response of a highly degraded lowland dry habitat plant community located on the south slope of east Moloka‘i, Hawai‘i, to reduction of browsing and grazing impacts caused by feral goats. For this study, vegetation response inside a fenced exclosure was compared to vegetation change in the area outside of the fence that was still accessible to goats. This study is part of the larger U.S. Geological Survey Ridge-to-Reef (USGS-R2R) research project conducted between 2008 and 2014 to better understand the magnitude of, and factors responsible for, increased erosion on Moloka‘i. The upslope erosion has resulted in heavy sedimentation of the near-shore coral reef ecosystem on the leeward side of the island. The project area and adjacent lands are managed by the East Moloka‘i Watershed Partnership (EMoWP) to restore the vegetation and reduce erosion on the leeward side of the island.Specific questions addressed in this vegetation change study include:How does the vegetation composition, structure, and cover respond to different population levels of feral goats in this area?Are there plant species that can be used as indicators of different population levels of goats?Can native plants recover and become dominant again with the reduction or elimination of goats from this area?Are there invasive plant species that respond favorably to reduction of goat populations and could result in additional management threats to this area over time?How does the succession of vegetation following goat control relate to the original composition and structure of the plant communities that were formerly found in this area?

Response of predators to Western Sandpiper nest exclosures

USGS Publications Warehouse

Niehaus, Amanda C.; Ruthrauff, Daniel R.; McCaffery, Brian J.

2004-01-01

In 2001, predator exclosures were used to protect nests of the Western Sandpiper (Calidris mauri) in western Alaska. During the exclosure experiment, nest contents in exclosures had significantly higher daily survival rates than control nests, however, late in the study predators began to cue in on exclosures and predate the nest contents. An Arctic Fox (Alopex lagopus) dug under one exclosure and took the newly hatched chicks, and Long-tailed Jaegers (Stercorarius longicaudus) learned to associate exclosures with active nests and repeatedly visited them. The jaegers attempted to gain access to exclosed nests and pursued adult sandpipers as they emerged from the exclosures. The exclosures were removed to reduce potential mortality to adult and young sandpipers, but subsequently, post-exclosure nests had lower daily survival rates than controls during the same time period. Predation of post-exclosure eggs and chicks highlighted the lasting influence of the exclosure treatment on offspring survival because predators probably remembered nest locations. Researchers are urged to use caution when considering use of predator exclosures in areas where jaegers occur.

High Arctic lemmings remain reproductively active under predator-induced elevated stress.

PubMed

Fauteux, Dominique; Gauthier, Gilles; Berteaux, Dominique; Palme, Rupert; Boonstra, Rudy

2018-04-12

Non-consumptive effects of predation have rarely been assessed in wildlife populations even though their impact could be as important as lethal effects. Reproduction of individuals is one of the most important demographic parameters that could be affected by predator-induced stress, which in turn can have important consequences on population dynamics. We studied non-consumptive effects of predation on the reproductive activity (i.e., mating and fertilization) of a cyclic population of brown lemmings exposed to intense summer predation in the Canadian High Arctic. Lemmings were live-trapped, their reproductive activity (i.e., testes visible in males, pregnancy/lactation in females) assessed, and predators were monitored during the summers of 2014 and 2015 within a 9 ha predator-reduction exclosure delimited by a fence and covered by a net, and on an 11 ha control area. Stress levels were quantified non-invasively with fecal corticosterone metabolites (FCM). We found that FCM levels of lemmings captured outside the predator exclosure (n = 50) were 1.6 times higher than inside (n = 51). The proportion of pregnant/lactating adult females did not differ between the two areas, nor did the proportion of adult scrotal males. We found that lemmings showed physiological stress reactions due to high predation risk, but had no sign of reduced mating activity or fertility. Thus, our results do not support the hypothesis of reproductive suppression by predator-induced stress.

Effects of environmental change on plant species density: Comparing predictions with experiments

USGS Publications Warehouse

Gough, L.; Grace, J.B.

1999-01-01

Ideally, general ecological relationships may be used to predict responses of natural communities to environmental change, but few attempts have been made to determine the reliability of predictions based on descriptive data. Using a previously published structural equation model (SEM) of descriptive data from a coastal marsh landscape, we compared these predictions against observed changes in plant species density resulting from field experiments (manipulations of soil fertility, flooding, salinity, and mammalian herbivory) in two areas within the same marsh. In general, observed experimental responses were fairly consistent with predictions. The largest discrepancy occurred when sods were transplanted from high- to low-salinity sites and herbivores selectively consumed a particularly palatable plant species in the transplanted sods. Individual plot responses to some treatments were predicted more accurately than others. Individual fertilized plot responses were not consistent with predictions (P > 0.05), nor were fenced plots (herbivore exclosures; R2 = 0.15) compared to unfenced plots (R2 = 0.53). For the remaining treatments, predictions reasonably matched responses (R2 = 0.63). We constructed an SEM for the experimental data; it explained 60% of the variance in species density and showed that fencing and fertilization led to decreases in species density that were not predicted from treatment effects on community biomass or observed disturbance levels. These treatments may have affected the ratio of live to dead biomass, and competitive exclusion likely decreased species density in fenced and fertilized plots. We conclude that experimental validation is required to determine the predictive value of comparative relationships derived from descriptive data.

Vegetation species diversity inside and outside exclosures in sagebrush, salt desert shrub, and aspen communities

Treesearch

W. A. Laycock; Dale Bartos

1999-01-01

Vegetation was sampled inside and outside eight exclosures in salt desert shrub and sagebrush vegetation types in Southwestern Wyoming and eight exclosures in aspen vegetation in southern Utah. Only species richness has been examined thus far. Five of the eight Wyoming exclosures had an average of 11% more plant species present outside the exclosure than inside.

Effects of private-land use, livestock management, and human tolerance on diversity, distribution, and abundance of large african mammals.

PubMed

Kinnaird, Margaret F; O'brien, Timothy G

2012-12-01

Successful conservation of large terrestrial mammals (wildlife) on private lands requires that landowners be empowered to manage wildlife so that benefits outweigh the costs. Laikipia County, Kenya, is predominantly unfenced, and the land uses in the area allow wide-ranging wildlife to move freely between different management systems on private land. We used camera traps to sample large mammals associated with 4 different management systems (rhinoceros sanctuaries, no livestock; conservancies, intermediate stocking level; fenced ranches, high stocking level; and group ranches, high stocking level, no fencing, pastoralist clan ownership) to examine whether management and stocking levels affect wildlife. We deployed cameras at 522 locations across 8 properties from January 2008 through October 2010 and used the photographs taken during this period to estimate richness, occupancy, and relative abundance of species. Species richness was highest in conservancies and sanctuaries and lowest on fenced and group ranches. Occupancy estimates were, on average, 2 and 5 times higher in sanctuaries and conservancies as on fenced and group ranches, respectively. Nineteen species on fenced ranches and 25 species on group ranches were considered uncommon (occupancy < 0.1). The relative abundance of most species was highest or second highest in sanctuaries and conservancies. Lack of rights to manage and utilize wildlife and uncertain land tenure dampen many owners' incentives to tolerate wildlife. We suggest national conservation strategies consider landscape-level approaches to land-use planning that aim to increase conserved areas by providing landowners with incentives to tolerate wildlife. Possible incentives include improving access to ecotourism benefits, forging agreements to maintain wildlife habitat and corridors, resolving land-ownership conflicts, restoring degraded rangelands, expanding opportunities for grazing leases, and allowing direct benefits to landowners through wildlife harvesting. . © 2012 Society for Conservation Biology.

Bird exclosures for branches and whole trees.

Treesearch

Robert W. Campbell; Torolf R. Torgersen; Steven C. Forrest; Lorna C. Youngs

1981-01-01

Two types of lightweight, portable bird exclosures are described. One is for individual branches or branch tips; the other is for whole trees up to 9 m tall. Several alternative configurations and uses of these exclosures are discussed.

Identifying impediments to long-distance mammal migrations.

PubMed

Seidler, Renee G; Long, Ryan A; Berger, Joel; Bergen, Scott; Beckmann, Jon P

2015-02-01

In much of the world, the persistence of long-distance migrations by mammals is threatened by development. Even where human population density is relatively low, there are roads, fencing, and energy development that present barriers to animal movement. If we are to conserve species that rely on long-distance migration, then it is critical that we identify existing migration impediments. To delineate stopover sites associated with anthropogenic development, we applied Brownian bridge movement models to high-frequency locations of pronghorn (Antilocapra americana) in the Greater Yellowstone Ecosystem. We then used resource utilization functions to assess the threats to long-distance migration of pronghorn that were due to fences and highways. Migrating pronghorn avoided dense developments of natural gas fields. Highways with relatively high volumes of traffic and woven-wire sheep fence acted as complete barriers. At crossings with known migration bottlenecks, use of high-quality forage and shrub habitat by pronghorn as they approached the highway was lower than expected based on availability of those resources. In contrast, pronghorn consistently utilized high-quality forage close to the highway at crossings with no known migration bottlenecks. Our findings demonstrate the importance of minimizing development in migration corridors in the future and of mitigating existing pressure on migratory animals by removing barriers, reducing the development footprint, or installing crossing structures. © 2014 Society for Conservation Biology.

Riparian livestock exclosure research in the western United States: a critique and some recommendations.

PubMed

Sarr, Daniel A

2002-10-01

Over the last three decades, livestock exclosure research has emerged as a preferred method to evaluate the ecology of riparian ecosystems and their susceptibility to livestock impacts. This research has addressed the effects of livestock exclusion on many characteristics of riparian ecosystems, including vegetation, aquatic and terrestrial animals, and geomorphology. This paper reviews, critiques, and provides recommendations for the improvement of riparian livestock exclosure research. Exclosure-based research has left considerable scientific uncertainty due to popularization of relatively few studies, weak study designs, a poor understanding of the scales and mechanisms of ecosystem recovery, and selective, agenda-laden literature reviews advocating for or against public lands livestock grazing. Exclosures are often too small (<50 ha) and improperly placed to accurately measure the responses of aquatic organisms or geomorphic processes to livestock removal. Depending upon the site conditions when and where livestock exclosures are established, postexclusion dynamics may vary considerably. Systems can recover quickly and predictably with livestock removal (the "rubber band" model), fail to recover due to changes in system structure or function (the "Humpty Dumpty" model), or recover slowly and remain more sensitive to livestock impacts than they were before grazing was initiated (the "broken leg" model). Several initial ideas for strengthening the scientific basis for livestock exclosure research are presented: (1) incorporation of meta-analyses and critical reviews. (2) use of restoration ecology as a unifying conceptual framework; (3) development of long-term research programs; (4) improved exclosure placement/ design; and (5) a stronger commitment to collection of pretreatment data.

Species richness inside and outside long-term exclosures

Treesearch

W. A. Laycock; D. L. Bartos; K. D. Klement

2004-01-01

Recent environmental literature contains claims that livestock grazing has caused reduction in species diversity on Western rangelands. Data of species richness (number of species) is presented from inside and outside 24 long-term exclosures in Montana, Utah, and Wyoming. For the average of all exclosures there was no difference between species richness inside and...

Results of deer exclosure studies in northeastern Pennsylvania

Treesearch

E.L. Shafer; T. J. Grisez; Ed Sowa

1961-01-01

To demonstrate how deer browsing affects natural tree seedling and sprout reproduction, two groups of deer exclosures were established in the Pocono Mountains of northeastern Pennsylvania. Study of these exclosures after seven growing seasons confirms what other studies elsewhere have found: that when deer are too numerous for their natural food supply, it is...

Potential effects of the United States-Mexico border fence on wildlife.

PubMed

Flesch, Aaron D; Epps, Clinton W; Cain, James W; Clark, Matt; Krausman, Paul R; Morgart, John R

2010-02-01

Security infrastructure along international boundaries threatens to degrade connectivity for wildlife. To explore potential effects of a fence under construction along the U.S.-Mexico border on wildlife, we assessed movement behavior of two species with different life histories whose regional persistence may depend on transboundary movements. We used radiotelemetry to assess how vegetation and landscape structure affect flight and natal dispersal behaviors of Ferruginous Pygmy-Owls (Glaucidium brasilianum), and satellite telemetry, gene-flow estimates, and least-cost path models to assess movement behavior and interpopulation connectivity of desert bighorn sheep (Ovis canadensis mexicana). Flight height of Pygmy-Owls averaged only 1.4 m (SE 0.1) above ground, and only 23% of flights exceeded 4 m. Juvenile Pygmy-Owls dispersed at slower speeds, changed direction more, and had lower colonization success in landscapes with larger vegetation openings or higher levels of disturbance (p < or = 0.047), which suggests large vegetation gaps coupled with tall fences may limit transboundary movements. Female bighorn sheep crossed valleys up to 4.9 km wide, and microsatellite analyses indicated relatively high levels of gene flow and migration (95% CI for F(ST)=0.010-0.115, Nm = 1.9-24.8, M =10.4-15.4) between populations divided by an 11-km valley. Models of gene flow based on regional topography and movement barriers suggested that nine populations of bighorn sheep in northwestern Sonora are linked by dispersal with those in neighboring Arizona. Disruption of transboundary movement corridors by impermeable fencing would isolate some populations on the Arizona side. Connectivity for other species with similar movement abilities and spatial distributions may be affected by border development, yet mitigation strategies could address needs of wildlife and humans.

Pine hollow exclosures: Effect of browsing on an aspen community sprayed with 2,4-D

Treesearch

Dale L. Bartos; Roy O. Harniss

1990-01-01

The Pine Hollow aspen (Populus tremuloides) exclosures on the Ashley National Forest in eastern Utah were sampled in 1984, 19 years after they were established. The effects of 2,4-D, wildlife, and cattle on plant succession were evaluated. Two exclosures were used to protect the sprayed area from (1) all animal use and (2) only livestock use. A third sprayed area was...

Grande Ronde Basin Fish Habitat Enhancement Project, Annual Report 2002-2003.

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

McGowan, Vance

On July 1, 1984 the Bonneville Power Administration and the Oregon Department of Fish and Wildlife entered into an agreement to initiate fish habitat enhancement work in the Joseph Creek subbasin of the Grande Ronde River Basin in northeast Oregon. In July of 1985 the Upper and Middle Grande Ronde River, and Catherine Creek subbasins were included in the intergovernmental contract, and on March 1, 1996 the Wallowa River subbasin was added. The primary goal of 'The Grande Ronde Basin Fish Habitat Enhancement Project' is to create, protect, and restore riparian and instream habitat for anadromous salmonids, thereby maximizing opportunitiesmore » for natural fish production within the basin. This project provided for implementation of Program Measure 703 (C)(1), Action Item 4.2 of the Northwest Power Planning Council's Columbia River Basin Fish and Wildlife Program (NPPC, 1987), and continues to be implemented as offsite mitigation for mainstem fishery losses caused by the Columbia River hydro-electric system. All work conducted by the Oregon Department of Fish and Wildlife is on private lands and therefore requires that considerable time be spent developing rapport with landowners to gain acceptance of, and continued cooperation with this program throughout 10-15 year lease periods. This project calls for passive regeneration of habitat, using riparian exclosure fencing as the primary method to restore degraded streams to a normative condition. Active remediation techniques using plantings, off-site water developments, site-specific instream structures, or whole channel alterations are also utilized where applicable. Individual projects contribute to and complement ecosystem and basin-wide watershed restoration efforts that are underway by state, federal, and tribal agencies, and local watershed councils. Work undertaken during 2002 included: (1) Implementing 1 new fencing project in the Wallowa subbasin that will protect an additional 0.95 miles of stream and 22.9 acres of habitat; (2) Conducting instream work activities in 3 streams to enhance habitat and/or restore natural channel dimensions, patterns or profiles; (3) Planting 31,733 plants along 3.7 stream miles, (4) Establishing 71 new photopoints and retaking 254 existing photopoint pictures; (5) Monitoring stream temperatures at 12 locations on 6 streams; (6) Completing riparian fence, water gap and other maintenance on 100.5 miles of project fences. Since initiation of the project in 1984 over 68.7 miles of anadromous fish bearing streams and 1,933 acres of habitat have been protected, enhanced and maintained.« less

Effect of cattle exclosures on Columbia Spotted Frog abundance

USGS Publications Warehouse

Adams, Michael J.; Pearl, Christopher; Chambert, Thierry; Mccreary, Brome; Galvan, Stephanie; Rowe, Jennifer

2018-01-01

Livestock grazing is an important land use in the western USA and can have positive or negative effects on amphibians. Columbia Spotted Frog (Rana luteiventris) often use ponds that provide water for cattle. We conducted a long-term manipulative study on US Forest Service land in northeastern Oregon to determine the effects of full and partial exclosures that limited cattle access to ponds used by frogs. We found weak evidence of a short-term increase in abundance that did not differ between full and partial exclosures and that diminished with continuing exclusion of cattle. The benefit of exclosures was small relative to the overall decline in breeding numbers that we documented. This suggests that some protection can provide a short-term boost to populations.

Influence of deer abundance on the abundance of questing adult Ixodes scapularis (Acari: Ixodidae)

USGS Publications Warehouse

Ginsberg, H.S.; Zhioua, E.

1999-01-01

Nymphal and adult Ixodes scapularis Say were sampled by flagging at 2 sites on a barrier island, Fire Island, NY, and at 2 sites on the nearby mainland. Nymphal densities did not differ consistently between island and mainland sites, but adult densities were consistently lower on the island. We tested whether lower adult densities on the island resulted from greater nymphal mortality on the island than the mainland, or whether adult ticks on the island were poorly sampled by flagging because they had attached abundantly to deer, which were common on Fire Island. Differential nymphal mortality on islands vs. mainland did not explain this difference in adult densities because survival of flat and engorged nymphs in enclosures was the same at island and mainland sites. Ticks were infected by parasitic wasps on the island and not the mainland, but the infection rate (4.3%) was too low to explain the difference in adult tick densities. In contrast, exclusion of deer by game fencing on Fire Island resulted in markedly increased numbers of adult ticks in flagging samples inside compared to samples taken outside the exclosures. Therefore, the scarcity of adult ticks in flagging samples on Fire Island resulted, at least in part, from the ticks being unavailable to flagging samples because they were on deer hosts. Differences in the densities of flagged ticks inside and outside the exclosures were used to estimate the percentage of questing adults on Fire Island that found deer hosts, excluding those that attached to other host species. Approximately 56% of these questing adult ticks found deer hosts in 1995 and 50% found deer hosts in 1996. Therefore, in areas where vertebrate hosts are highly abundant, large proportions of the questing tick population can find hosts. Moreover, comparisons of tick densities at different sites by flagging can potentially be biased by differences in host densities among sites.

Managing habitat to slow or reverse population declines of the Columbia spotted frog in the Northern Great Basin

USGS Publications Warehouse

Pilliod, David S.; Richard D. Scherer,

2015-01-01

Evaluating the effectiveness of habitat management actions is critical to adaptive management strategies for conservation of imperiled species. We quantified the response of a Great Basin population of the Columbia spotted frog (Rana luteiventris) to multiple habitat improvement actions aimed to reduce threats and reverse population declines. We used mark-recapture data for 1,394 adult frogs that had been marked by state, federal, and university biologists in 9 ponds representing a single population over a 16-year period from 1997 to 2012. With the use of demographic models, we assessed population-level effects of 1) a grazing exclosure constructed around 6 stock ponds that had been used to water livestock for decades before being fully fenced in 2003, and 2) the construction of 3 new stock ponds in 2003 to provide alternative water sources for livestock and, secondarily, to provide additional frog habitat. These management actions were implemented in response to a decline of more than 80% in population size from 1997 to 2002. We found evidence that excluding cattle from ponds and surrounding riparian habitats resulted in higher levels of frog production (more egg masses), higher adult frog recruitment and survival, and higher population growth rate. We also found that frogs colonized the newly constructed stock ponds within 3 years and frogs began breeding in 2 of them after 5 years. The positive effects of the cattle exclosure and additional production from the new ponds, although notable, did not result in full recovery of the population even 9 years later. This slow recovery may be partly explained by the effects of weather on recruitment rates, particularly the negative effects of harsher winters with late springs and higher fall temperatures. Although our findings point to potential successes of habitat management aimed at slowing or reversing rapidly declining frog populations, our study also suggests that recovering from severe population declines can take many years because of demographic and environmental processes. 

Comparison of the effects of artificial and natural barriers on large African carnivores: implications for interspecific relationships and connectivity.

PubMed

Cozzi, Gabriele; Broekhuis, Femke; McNutt, J Weldon; Schmid, Bernhard

2013-05-01

1. Physical barriers contribute to habitat fragmentation, influence species distribution and ranging behaviour, and impact long-term population viability. Barrier permeability varies among species and can potentially impact the competitive balance within animal communities by differentially affecting co-occurring species. The influence of barriers on the spatial distribution of species within whole communities has nonetheless received little attention. 2. During a 4-year period, we studied the influence of a fence and rivers, two landscape features that potentially act as barriers on space use and ranging behaviour of lions Panthera leo, spotted hyenas Crocuta crocuta, African wild dogs Lycaon pictus and cheetahs Acinonyx jubatus in Northern Botswana. We compared the tendencies of these species to cross the barriers using data generated from GPS-radio collars fitted to a total of 35 individuals. Barrier permeability was inferred by calculating the number of times animals crossed a barrier vs. the number of times they did not cross. Finally, based on our results, we produced a map of connectivity for the broader landscape system. 3. Permeability varied significantly between fence and rivers and among species. The fence represented an obstacle for lions (permeability = 7.2%), while it was considerably more permeable for hyenas (35.6%) and wild dogs and cheetahs (≥ 50%). In contrast, the rivers and associated floodplains were relatively permeable to lions (14.4%) while they represented a nearly impassable obstacle for the other species (<2%). 4. The aversion of lions to cross the fence resulted in a relatively lion-free habitat patch on one side of the fence, which might provide a potential refuge for other species. For instance, the competitively inferior wild dogs used this refuge significantly more intensively than the side of the fence with a high presence of lions. 5. We showed that the influence of a barrier on the distribution of animals could potentially result in a broad-scale modification of community structure and ecology within a guild of co-occurring species. As habitat fragmentation increases, understanding the impact of barriers on species distributions is thus essential for the implementation of landscape-scale management strategies, the development and maintenance of corridors and the enhancement of connectivity. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

Effects of pollination timing and distance on seed production in a dioecious weed Silene latifolia

NASA Astrophysics Data System (ADS)

Anderson, Jay F.; Duddu, Hema S. N.; Shirtliffe, Steven J.; Benaragama, Dilshan; Syrovy, Lena D.; Stanley, Katherine A.; Haile, Teketel A.

2015-11-01

Silene latifolia Poir. (white cockle or white campion) is an important invasive weed in North American agriculture. It exhibits dioecy, therefore, both male and female plants are required in order for seed production to occur. However, dioecious species being invasive is not common because of their limitations in pollination and subsequent seed production. The objective of this study is to determine the effect of pollination timing and distance on seed production of Silene latifolia. A series of experiments including pollination exclusion, timing and pollination distance were conducted in 2009 and 2010 at or around Saskatoon, Saskatchewan. For pollination exclusion, exclosures were built around the natural female plants for exclosure, sham-exclosure, and male and female combined treatments. Pollination timing was studied by applying exclosure, non-exclosure, night-exclosure, and day-exclosure treatments to individual female plants. Female plants were transplanted along a linear interval at six different distances from the pollen source to study the effect of pollination distance. S. latifolia was exclusively insect-pollinated and pollination occurred both day and night; however, in one year, pollination occurred mainly at night. Female plants that were in the range of 0-4 m from a compatible pollen source experienced no limitation to pollination. However, when the distance was increased further up to 128 m, pollination levels and subsequent seed production were declined. Moreover, there were differences in seed production between years suggesting that pollination was affected by the environmental conditions during pollination and the crop that white cockle was grown in. These experiments indicate that seed production in S. latifolia is limited by insect-pollination. Although there was pollination limitation for seed production at greater distances from a pollen source, the high fecundity rate (3000-18000 seeds per plant) resulted in a large seed output. Thus, we believe that a dioecious species may require characteristics that compensate the pollination limitation for a successful invasion.

Benthic grazing in a eutrophic river: cascading effects of zoobenthivorous fish mask direct effects of herbivorous fish

PubMed Central

Cob Chaves, Daniel; Richter, Marc; Mewes, Daniela; Schneider, Jörg; Hübner, Dirk; Winkelmann, Carola

2018-01-01

Benthic grazing strongly controls periphyton biomass. The question therefore arises whether benthic grazing could be used as a tool to reduce excessive growth of periphyton in nutrient-enriched rivers. Although benthic invertebrate grazers reduce the growth of periphyton, this is highly context dependent. Here we assessed whether the only obligate herbivorous fish in European rivers, the common nase (Chondrostoma nasus L.), is able to reduce periphyton biomass in a eutrophic river. We conducted three consecutive in situ experiments at low, intermediate and high densities of nase in the river using standard tiles on the river bottom naturally covered with periphyton that were accessible to fish and tiles that excluded fish foraging with electric exclosures. The biomass of benthic invertebrate grazers was very low relative to nase. We hypothesised that nase would reduce periphyton biomass on accessible tiles and therefore expected higher periphyton biomass on the exclosure tiles, at least at intermediate and high densities of nase in the river. Contrary to our expectation, the impact of fish grazing was low even at high fish density, as judged by the significantly lower chlorophyll a concentration on exclosure tiles even though the ash-free dry mass on accessible and exclosure tiles did not differ. The lower chlorophyll a concentrations on exclosure tiles might be explained by a higher biomass of invertebrate grazers on the exclosure tiles, which would indicate that the effect of invertebrate grazers was stronger than that of herbivorous fish grazers. The high biomass of invertebrate grazers on exclosure tiles likely arose from the exclusion of zoobenthivorous fish, which occur in the river at high densities. The results of our small-scale experiments suggested that cascading top-down effects of zoobenthivorous fish have a higher impact on periphyton biomass than direct effects of herbivorous nase. PMID:29473006

Feral herbivores suppress mamane and other browse species on Mauna Kea, Hawaii

Treesearch

Paul G Scowcroft; Jon G. Giffin

1983-01-01

Abundance, survival, and growth ofmamane (Sophora chrysophylla) regeneration were determined inside and outside sheep exclosures located in heavily browsed portions of the mamane forest of Mauna Kea, Hawaii. Vegetational cover of other species was estimated. Mamane grew abundantly inside 16-year-old exclosures but was sparse outside. Height class...

Loss of eelgrass in Casco Bay, Maine, linked to Green Crab disturbance

USGS Publications Warehouse

Neckles, Hilary A.

2015-01-01

Over half of the Zostera marina (Eelgrass) cover disappeared from Casco Bay, ME, largely between 2012 and 2013. Eelgrass decline coincided with a population explosion of the invasive crab Carcinus maenas (European Green Crab). Green Crabs have been found to damage Eelgrass in Atlantic Canada through foraging activity, but destruction of established beds had not been documented in Maine. My objective was to determine whether loss of Eelgrass from Casco Bay was related to Green Crab disturbance. In September 2013, I transplanted Eelgrass shoots inside and outside of replicate Green Crab exclosures in a formerly vegetated area of upper Casco Bay. Following 26 d, mean survival of Eelgrass inside the exclosures was 82% and outside the exclosures was 24%. The mean plastochrone interval (time between formation of 2 successive leaves) of undamaged shoots was the same inside and outside the exclosures, and was comparable to published values from healthy Eelgrass beds in New England. Results implicate Green Crab bioturbation as a leading cause of Eelgrass loss from this system.

Manatee grazing impacts on a mixed species seagrass bed

USGS Publications Warehouse

Lefebvre, Lynn W.; Provancha, Jane A.; Slone, Daniel H.; Kenworthy, W. Judson

2017-01-01

The endangered manatee Trichechus manatus is one of few large grazers in seagrass systems. To assess the long-term impacts of repeated grazing on seagrasses, we selected a study site within Kennedy Space Center in the northern Banana River, Brevard County, Florida, that was typically grazed by large numbers of manatees in spring. Two 13x13 m manatee exclosures and 2 paired open plots of equal size were established at the study site in October 1990. Shoot counts, biomass, and species composition of the co-dominant seagrass species, Syringodium filiforme and Halodule wrightii, were sampled 3 times per year in all 4 plots between October 1990 and October 1994. We used a Bayesian modelling approach, accounting for the influence of depth, to detect treatment (exclosed vs. open) effects. S. filiforme shoot counts, total biomass, and frequency of occurrence significantly increased in the exclosures. By July 1993, mean biomass values in the exclosures (167 g dry wt m-2) greatly exceeded those in the open plots (28 g dry wt m-2). H. wrightii decreased in the exclosures by 1994. Initially, both S. filiforme and H. wrightii responded positively to release from manatee grazing pressure. As S. filiforme continued to become denser in the exclosures, it gradually replaced H. wrightii. Our findings may be helpful to biologists and managers interested in predicting seagrass recovery and manatee carrying capacity of repeatedly grazed seagrass beds in areas of special significance to manatees and seagrass conservation.

Climatic and Grazing Controls on Biological Soil Crust Nitrogen Fixation in Semi-arid Ecosystems

NASA Astrophysics Data System (ADS)

Schwabedissen, S. G.; Reed, S.; Lohse, K. A.; Magnuson, T. S.

2014-12-01

Nitrogen, next to water, is believed to be the main limiting resource in arid and semi-arid ecosystems. Biological soil crusts (biocrusts) -a surface community of mosses, lichens and cyanobacteria-have been found to be the main influx of "new" nitrogen (N) into many dryland ecosystems. Controls on biocrust N fixation rates include climate (temperature and moisture), phosphorus availability, and disturbance factors such as trampling, yet a systematic examination of climatic and disturbance controls on biocrusts communities is lacking. Biocrust samples were collected along an elevation gradient in the Reynolds Creek Experimental Watershed near Murphy, Idaho. Four sites were selected from a sagebrush steppe ecosystem with precipitation ranging from ≤250mm/yr to ≥1100mm/yr. Each site included 5 grazed plots and one historic exclosure plot that has been free from grazing for more than 40 years. Five samples each were collected from under plants and from interplant spaces from the grazed plots and exclosures and analyzed for potential N fixation using an acetylene reduction assay. We hypothesized that N fixation rates would be the highest in the exclosures of the two middle sites along the elevation gradient, due to the lack of disturbance and optimal temperature and moisture, respectively. As predicted, results showed higher rates of potential N fixation in exclosures than non-exclosures at a mid-elevation 8.4 ± 3.1 kg N/ha/yr in the exclosures compared to 1.8 ± 1.5 kg N/ha/yr indicating that grazing may reduce N fixation activity. Interestingly, rates were 2-5 times lower under plant canopies compared to interplant spaces at all but the highest elevation site. Findings from our study suggest that biocrust N fixation may be a dominant input of N into theses dryland systems and, in line with our hypotheses, that climate, location within the landscape, and disturbance may interact to regulate the rates of this fundamental ecosystem process.

Rangeland exclosures of northeastern Oregon: stories they tell (1936–2004).

Treesearch

Charles Grier Johnson

2007-01-01

Rangeland exclosures installed primarily in the 1960s, but with some from the 1940s, were resampled for changes in plant community structure and composition periodically from 1977 to 2004 on the Malheur, Umatilla, and Wallowa-Whitman National Forests in northeastern Oregon. They allow one to compare vegetation with all-ungulate exclusion (known historically as game...

Impacts of white-tailed deer on red trillium (Trillium recurvatum): defining a threshold for deer browsing pressure at the Indiana Dunes National Lakeshore

USGS Publications Warehouse

Pavlovic, Noel B.; Leicht-Young, Stacey A.; Grundel, Ralph

2014-01-01

Overabundant white-tailed deer (Odocoileus virginianus) have been a concern for land managers in eastern North America because of their impacts on native forest ecosystems. Managers have sought native plant species to serve as phytoindicators of deer impacts to supplement deer surveys. We analyzed experimental data about red trillium (Trillium recurvatum), large flowered trillium (T. grandiflorum), nodding trillium (T. cernuum), and declined trillium (T. flexipes) growth in paired exclosure (fenced) plots and control (unfenced) plots from 2002 to 2010 at the Indiana Dunes National Lakeshore. The latter two species lacked replication, so statistical analysis was not possible. All red trillium plants were surveyed for height-to-leaf, effects of browsing, and presence of flowers. Data from individuals in 2009 demonstrated a sigmoidal relationship between height-to-leaf and probability of flowering. The relationship on moraine soils was shifted to taller plants compared to those on sand substrates, with respectively 50 percent flowering at 18 and 16 cm and 33 percent flowering at 16 and 14 cm height-to-leaf. On a plot basis, the proportion of plants flowering was influenced by height to leaf, duration of protection, and deviation in rainfall. The proportion of plants flowering increased ninefold in exclosures (28 percent) compared to control plots (3 percent) over the 8 years of protection. The mean height-to-leaf was a function of the interaction between treatment and duration, as well as red trillium density. Changes in height-to-leaf in control plots from year to year were significantly influenced by an interaction between change in deer density and change in snowfall depth. There was a significant negative correlation between change in deer density and snowfall depth. Plants in the exclosures increased in height at a rate of 1.5 cm yr−1 whereas control plants decreased in height by 0.9 cm yr−1. In all, 78 percent of the control plots lacked flowering individuals over the 9 years of study, indicating that red trillium is being negatively affected by deer throughout the East Unit of the park. Of the five deer management zones studied, only one showed pre-impact height-to-leaf and flowering percentages in control plots that then declined after 2005. The results of this study demonstrate that Trillium species growing in the lands of the Indiana Dunes National Lakeshore are being suppressed reproductively by deer browsing. Specifically, we demonstrate, for the first time, the utility of using red trillium (Trillium recurvatum) height-to-leaf and percentage of flowering as indicators of the impacts of deer browsing. Application of the recommended thresholds demonstrates their utility in adopting red trillium as a phytoindicator of deer impact. Responses of plants to protection from deer suggest that deer culling might be necessary for 6 or more years for red trillium populations and rare trillium species to recover.

Grande Ronde Basin Fish Habitat Enhancement Project : 2007 Annual Report.

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

McGowan, Vance R.; Morton, Winston H.

2008-12-30

On July 1, 1984 the Bonneville Power Administration and the Oregon Department of Fish and Wildlife entered into an intergovernmental contract to initiate fish habitat enhancement work in the Joseph Creek subbasin of the Grande Ronde River Basin in northeast Oregon. In 1985 the Upper and Middle Grande Ronde River, and Catherine Creek subbasins were included in the contract, and in 1996 the Wallowa River subbasin was added. The primary goal of 'The Grande Ronde Basin Fish Habitat Enhancement Project' is to create, protect, and restore riparian and instream habitat for anadromous salmonids, thereby maximizing opportunities for natural fish productionmore » within the basin. This project provided for implementation of Program Measure 703 (C)(1), Action Item 4.2 of the Northwest Power Planning Council's Columbia River Basin Fish and Wildlife Program (NPPC, 1987), and continues to be implemented as offsite mitigation for mainstem fishery losses caused by the Columbia River hydro-electric system. All work conducted by the Oregon Department of Fish and Wildlife and partners is on private lands and therefore requires that considerable time be spent developing rapport with landowners to gain acceptance of, and continued cooperation with this program throughout 10-15 year lease periods. Both passive and active restoration treatment techniques are used. Passive regeneration of habitat, using riparian exclosure fencing and alternate water sources are the primary method to restore degraded streams when restoration can be achieved primarily through changes in management. Active restoration techniques using plantings, bioengineering, site-specific instream structures, or whole stream channel alterations are utilized when streams are more severely degraded and not likely to recover in a reasonable timeframe. Individual projects contribute to and complement ecosystem and basin-wide watershed restoration efforts that are underway by state, federal, and tribal agencies, and coordinated by the Grande Ronde Model Watershed Program (Project. No.199202601). Work undertaken during 2007 included: (1) Starting 1 new fencing project in the NFJD subbasin that will protect an additional 1.82 miles of stream and 216.2 acres of habitat; (2) Constructing 0.47 miles of new channel on the Wallowa River to enhance habitat, restore natural channel dimensions, pattern and profile and reconnect approximately 18 acres of floodplain and wetland habitat; (3) Planting 22,100 plants along 3 streams totaling 3.6 stream miles; (4) Establishing 34 new photopoints on 5 projects and retaking 295 existing photopoint pictures; (5) Monitoring stream temperatures at 10 locations on 5 streams and conducting other monitoring activities; (6) Completing riparian fence, water gap and other maintenance on 116.8 miles of project fences; (7) Initiated writing of a comprehensive project summary report that will present a summary of conclusions of the benefits to focal species and management recommendations for the future. Since initiation of this program 56 individual projects have been implemented, monitored and maintained along 84.8 miles of anadromous fish bearing streams that protect and enhance 3,501 acres of riparian and instream habitat.« less

Grand Ronde Basin Fish Habitat Enhancement Project, 2008 Annual Report.

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

McGowan, Vance R.; Morton, Winston H.

2009-07-01

On July 1, 1984 the Bonneville Power Administration and the Oregon Department of Fish and Wildlife entered into an intergovernmental contract to initiate fish habitat enhancement work in the Joseph Creek subbasin of the Grande Ronde River Basin in northeast Oregon. In 1985 the Upper and Middle Grande Ronde River, and Catherine Creek subbasins were included in the contract, and in 1996 the Wallowa River subbasin was added. The primary goal of 'The Grande Ronde Basin Fish Habitat Enhancement Project' is to create, protect, and restore riparian and instream habitat for anadromous salmonids, thereby maximizing the opportunities for natural fishmore » production within the basin. This project originally provided for implementation of Program Measure 703 (C)(1), Action Item 4.2 of the Northwest Power Planning Council's Columbia River Basin Fish and Wildlife Program (NPPC, 1987), and continues to be implemented under revisions of the Fish and Wild Program as offsite mitigation for mainstem fishery losses caused by the Columbia River hydro-electric system. All work conducted by the Oregon Department of Fish and Wildlife and partners is on private lands and therefore requires considerable time be spent developing rapport with landowners to gain acceptance, and continued cooperation with this program throughout 10-15 year lease periods. Both passive and active restoration treatment techniques are used. Passive regeneration of habitat, using riparian exclosure fencing and alternate water sources, is the primary method to restore degraded streams when restoration can be achieved primarily through changes in management. Active restoration techniques using plantings, bioengineering, site-specific instream structures, or whole stream channel alterations are utilized when streams are more severely degraded and not likely to recover in a reasonable timeframe. Individual projects contribute to and complement ecosystem and basin-wide watershed restoration efforts that are underway by state, federal, and tribal agencies, and coordinated by the Grande Ronde Model Watershed Program (Project. No. 199202601). Work undertaken during 2008 included: (1) completing 1 new fencing project in the North Fork John Day subbasin that protects 1.82 miles of stream and 216.2 acres of habitat, and 1 fencing project in the Wallowa subbasin that protects an additional 0.59 miles of stream and 42.5 acres of habitat; (2) constructing 0.47 miles of new channel on the Wallowa river to enhance habitat, restore natural channel dimensions, pattern and profile and reconnect approximately 18 acres of floodplain and wetland habitat; (3) planting 10,084 plants along 0.5 miles of the Wallowa Riverproject; (4) establishing 34 new photopoints on 5 projects and retaking 295 existing photopoint pictures; (5) monitoring stream temperatures at 10 locations on 5 streams and conducting other monitoring activities; (6) completing riparian fence, water gap and other maintenance on 116.8 miles of project fences; and (7) completed a comprehensive project summary report to the Independent Scientific Review panel (ISRP) that provided our conclusions regarding benefits to focal species, along with management recommendations for the future. Since initiation of this program 57 individual projects have been implemented, monitoring and maintained along 84.9 miles of anadromous fish bearing streams, that protect and enhance 3,564 acres of riparian and instream habitat.« less

Efficacy of exclosures in conserving local shrub biodiversity in xeric sandy grassland, Inner Mongolia, China

Treesearch

Feng-Rui Li; Zhi-Yu Zhou; Li-Ya Zhao; Ai-Sheng Zhang; Ling-Fen Kang

2007-01-01

This study investigated the abundance and frequency of occurrence of all shrub species present in the standing vegetation at four sites, including a 5-year exclosure (protected grassland) and three adjacent unprotected grazing sites that had been subjected to different levels of degradation (light, moderate and severe), in xeric sandy grassland of Inner Mongolia for...

Ungulate herbivory on Utah aspen: Assessment of longterm exclosures

Treesearch

Charles E. Kay; Dale L. Bartos

2000-01-01

The role of livestock grazing and big-game browsing in the decline of aspen (Populus tremuloides Michx.) in the Intermountain West has long been questioned.All known aspen exclosures (n=8) on the Dixie and Fishlake National Forests in south-central Utah were measured during late summer of 1995 and 1996 to determine aspen stem dynamics, successional status, and...

Species richness has not increased after long-term protection from grazing on sagebrush, aspen and tall forb rangelands

Treesearch

W. A. Laycock; Dale Bartos; Keith Klement

2001-01-01

Recent conservation biology and environmental literature contains claims that livestock grazing has caused and continues to cause reduction in species diversity on Western rangelands, especially public rangelands. This paper present quantitative data on species richness (number of species) inside and outside 24 long-term exclosures; 8 exclosures in aspen vegetation in...

Grindstone Flat and Big Flat enclosures - 41-year record of changes in clearcut aspen communities

Treesearch

Walter F. Mueggler; Dale L. Bartos

1977-01-01

The role of deer and cattle in the failure of aspen stands to regenerate on Beaver Mountain in southern Utah was investigated by a series of exclosures constructed in 1934. Three-fourths of each exclosure was clearcut of aspen in 1934. Aspen reproduction, shrubs, and herbaceous understory were measured in 1937, 1942, 1949, and 1975. Implications of wildlife and...

The effect of small rodents on northern red oak acorns in north-central West Virginia

Treesearch

Linda S. Gribko; David M. Hix

1993-01-01

The effects of small mammals on surface-sown northern red oak (Quercus rubra) acorns was assessed in highly productive Appalachian hardwood stands. Study plots were established in October 1990 on excellent (average site index of 89 feet for red oak) and good (average site index of 72 feet) sites. Each plot included: 1) a rodent-proof exclosure, 2) an exclosure...

The effects of prescribed fire and ungulate herbivory and 7 years postburn in the upland bitterbrush (Purshia tridentata) communities of Rocky Mountain National Park, Colorado

Treesearch

Kelly Nesvacil; Charles E. Olmsted

2008-01-01

A controlled, manipulative study utilizing exclosures was initiated in 1994 by Zeigenfuss and others (2002) to assess the effects of prescribed fire and ungulate herbivory in the bitterbrush communities of Rocky Mountain National Park (RMNP). Four sites were chosen randomly from all available bitterbrush communities in RMNP wherein exclosures were erected (March/May...

Contrasting impacts of reindeer grazing in two tundra grasslands

NASA Astrophysics Data System (ADS)

Vowles, Tage; Lovehav, Cajsa; Molau, Ulf; Björk, Robert G.

2017-03-01

Plant communities in Arctic and alpine areas are changing due to higher temperatures and longer vegetation periods and it is uncertain how this will affect plant-herbivore dynamics. For instance, relatively fast-growing, deciduous shrub species that are the most responsive to warming may also be the most targeted by herbivores such as reindeer, giving less palatable evergreen shrubs the chance to expand. Using herbivore exclosures, we have studied how two grasslands with contrasting nutrient and moisture regimes, a dry, nutrient-poor alpine grass heath and a wet, productive low herb meadow, changed between 1995 and 2012, in grazed and ungrazed conditions. At the grass heath, evergreen low shrub abundance had more than doubled, regardless of grazer treatment, whereas at the low herb meadow, evergreen shrubs had increased only outside exclosures while deciduous tall shrubs and forbs were significantly more abundant inside exclosures. Deciduous tall shrubs were also significantly taller in exclosures. These contrasting findings suggest that the impact of herbivores is to a great deal determined by their influence on competitive interactions between plant species, and therefore depends on the underlying composition of the plant community. Consequently, as the balance in these competitive interactions is shifting due to climate warming, we conclude that the potential of herbivory to influence this balance is considerable yet highly site dependent.

Spiders and subsidies: results from the riparian zone of a coastal temperate rainforest.

PubMed

Marczak, Laurie B; Richardson, John S

2007-07-01

1. Aquatic insects emerging from streams can provide an important energy subsidy to recipient consumers such as riparian web-building spiders. This subsidy has been hypothesized to be of little importance where the primary productivity of the recipient habitat exceeds that of the donor habitat. 2. To test this hypothesis, we manipulated emerging stream insect abundance in a productive riparian rainforest in a replicated design using greenhouse-type exclosures, contrasted with unmanipulated stream reaches (four exclosures on two streams). 3. Experimental exclosures resulted in a 62.9% decrease in aquatic insect abundance in exclusion reaches compared with control reaches. The overall density of riparian spiders was significantly positively correlated with aquatic insect abundances. Horizontal orb weavers (Tetragnathidae) showed a strong response to aquatic insect reduction - abundance at exclosure sites was 57% lower than at control sites. Several spider families that have not been associated with tracking aquatic insect subsidies also showed significantly decreased abundance when aquatic insects were reduced. 4. This result is contrary to predictions of weak subsidy effects where recipient net primary productivity is high. These results suggest that predicting the importance of resource subsidies for food webs requires a focus on the relative abundance of subsidy materials in recipient and donor habitats and not simply on the total flux of energy between systems.

Weak trophic interactions among birds, insects and white oak saplings (Quercus alba)

USGS Publications Warehouse

Lichtenberg, J.S.; Lichtenberg, D.A.

2002-01-01

We examined the interactions among insectivorous birds, arthropods and white oak saplings (Quercus alba L.) in a temperate deciduous forest under 'open' and 'closed' canopy environments. For 2 y, we compared arthropod densities, leaf damage and sapling growth. Saplings from each canopy environment were assigned to one of four treatments: (1) reference, (2) bird exclosure, (3) insecticide and (4) exclosure + insecticide. Sap-feeding insects were the most abundant arthropod feeding guild encountered and birds reduced sap-feeder densities in 1997, but not in 1998. Although there was no detectable influence of birds on leaf-chewer densities in either year, leaf damage to saplings was greater within bird exclosures than outside of bird exclosures in 1997. Insecticide significantly reduced arthropod densities and leaf damage to saplings, but there was no corresponding increase in sapling growth. Growth and biomass were greater for saplings in more open canopy environments for both years. Sap-feeder densities were higher on closed canopy than open canopy saplings in 1997, but canopy environment did not influence the effects of birds on lower trophic levels. Although previous studies have found birds to indirectly influence plant growth and biomass, birds did not significantly influence the growth or biomass of white oak saplings during our study.

The effects of herbivory on neighbor interactions along a coastal marsh gradient

USGS Publications Warehouse

Taylor, K.L.; Grace, J.B.; Marx, B.D.

1997-01-01

Many current theories of community function are based on the assumption that disturbances such as herbivory act to reduce the importance of neighbor interactions among plants. In this study, we examined the effects of herbivory (primarily by nutria, Myocastor coy-pus) on neighbor interactions between three dominant grasses in three coastal marsh communities, fresh, oligohaline, and mesohaline. The grasses studied were Panicum virgatum, Spartina patens, and Spartina alterniflora, which are dominant species in the fresh, oligohaline, and mesohaline marshes, respectively. Additive mixtures and monocultures of transplants were used in conjunction with exclosure fences to determine the impact of herbivory on neighbor interactions in the different marsh types. Herbivory had a strong effect on all three species and was important in all three marshes. In the absence of herbivores, the impact of neighbors was significant for two of the species (Panicum virgatum and Spartina patens) and varied considerably between environments, with competition intensifying for Panicum virgatum and decreasing for Spartina patens with increasing salinity. Indications of positive neighbor effects (mutualisms) were observed for both of these species, though in contrasting habitats and to differing degrees. In the presence of herbivores, however, competitive and positive effects were eliminated. Overall, then, it was observed that in this case, intense herbivory was able to override other biotic interactions such as competition and mutualism, which were not detectable in the presence of herbivores.

Chronic over browsing and biodiversity collapse in a forest understory in Pennsylvania: Results from a 60 year-old deer exclusion plot

Treesearch

Chandra Goetsch; Jennifer Wigg; Alejandro A. Royo; Todd Ristau; Walter P. Carson

2011-01-01

We evaluated the impact of chronic deer over browsing on the diversity and abundance of understory forbs and shrubs within a forest stand in the Allegheny High Plateau Region of Pennsylvania by comparing vegetation inside a 60-year-old exclosure to vegetation within an adjacent reference site. This is the oldest known exclosure in the Eastern Deciduous Forest. Browsing...

Over-browsing in Pennsylvania creates a depauperate forest dominated by an understory tree: results from a 60-year-old deer exclosure

Treesearch

Morgan Kain; Loretta Battaglia; Alejandro Royo; Walter P. Carson

2011-01-01

We evaluated the impact of long-term over-browsing by white-tailed deer on the diversity and density of trees in a forest in the Allegheny High Plateau region of central Pennsylvania.We compared tree diversity and density inside a 60 year-old deer exclosure to an adjacent reference site. Browsing caused a 55-100% decline in density of four tree species (Prunus...

Influence of elk grazing on soil properties in Rocky Mountain National Park

USGS Publications Warehouse

Binkley, Dan; Singer, F.; Kaye, M.; Rochelle, R.

2003-01-01

We used three 35-year exclosures to examine the effects of high elk populations on a variety of soil properties in three vegetation types: upland sagebrush, aspen, and meadow. Grazing and hoof action by elk significantly increased bulk density (from 0.87 kg/l ungrazed to 0.94 kg/l grazed), with greater effects on soils with fewer rocks. Grazing substantially reduced extractable calcium, magnesium, potassium and phosphorus in the sagebrush type, but not in the aspen or meadow types. The only grazing effect on pH came in aspen types, where grazing prevented aspen establishment, and kept soil pH about 0.7 units higher than under aspen inside the exclosures. Grazing had no overall effect on total soil C and N across all exclosures and vegetation types. The availability of soil nitrogen, indexed by in-field resin bags and net mineralization in soil cores, showed little overall effect of grazing. Limited data on soil leaching indicated a possibility of strong increases in nitrate leaching with grazing for an aspen vegetation type at one exclosure. Although we found little effect of grazing on soil N supply, we note that N fertilization doubled the production of grasses and shrubs; if grazing eventually led to changes in soil N supply, species composition and growth would likely change. ?? 2003 Elsevier B.V. All rights reserved.

Differential consumption of eastern red cedar (Juniperus virginiana) by avian and mammalian guilds: Implications for tree invasion

USGS Publications Warehouse

Horncastle, V.J.; Hellgren, E.C.; Mayer, P.M.; Engle, David M.; Leslie, D.M.

2004-01-01

Increased abundance and distribution of eastern redcedar (Juniperns virginiannus), a native species in the Great Plains, has been associated with changes in ecosystem functioning and landscape cover. Knowledge of the main consumers and dispersal agents of eastern red cedar cones is essential to understanding the invasive spread of the species. We examined animal removal of cedar cones in three habitats (tallgrass prairie, eastern red cedar and woodland-prairie margins) in the Cross Timbers ecoregion using three exclosure treatments during autumn and winter. Exclosure treatments excluded study trees from ungulates, from terrestrial rodents and ungulates or from neither (control). Loss of cones from branches varied by a habitat-time interaction, but was not affected by exclosure type. Loss of cones from containers located under experimental trees varied by a habitat-treatment-time interaction. In December and January, cone consumption from containers in no-exclosure treatments was highest in margins, followed by tallgrass prairie and eastern red cedar habitats. We conclude birds consumed the majority of cones from branches and small-and medium-sized mammals consumed cones on the ground. Both birds and mammals likely contribute to the spread of eastern red cedar but at different scales. Limiting invasion of eastern red cedar in forests may require early detection and selective removal of pioneer seedlings in cross timbers and other habitats that attract a high diversity or density of frugivores.

Long-term impacts of grazing intensity on soil carbon sequestration and selected soil properties in the arid Eastern Cape, South Africa.

PubMed

Talore, Deribe G; Tesfamariam, Eyob H; Hassen, Abubeker; Du Toit, J C O; Klampp, Katja; Jean-Francois, Soussana

2016-04-01

Little is known about how basic soil properties respond to contrasting grazing intensities in the Karoo biome, South Africa. The aim of this study was to investigate impacts of long-term (>75 years) grazing at 1.18 heads ha(-1) (heavy; CGH), 0.78 heads ha(-1) (light; CGL), and exclosure on selected soil properties. Soil samples were collected to a depth of 60 cm from the long-term experimental site of Grootfontein Agricultural Development Institute, Eastern Cape. The samples were analyzed for C, N, bulk density and infiltration rate, among others. Generally, heavy and light grazing reduced soil N storage by 27.5% and 22.6%, respectively, compared with the exclosure. Animal exclusion improved water infiltration rate and C stocks significantly (P < 0.05), which was 0.128, 0.097, and 0.093 Mg ha(-1) yr(-1) for exclosure, CGL and CGH, respectively. Soil penetration resistance was higher for grazing treatments in the top 3-7 cm soil layer but for exclosure at the top 1 cm soil surface. Although livestock exclusion has the potential to improve C sequestration, a sufficient resting period for 1-2 years followed by three consecutive grazing years at light stocking rate would be ideal for sustainable livestock production in this arid region of South Africa. © 2015 Society of Chemical Industry.

Evaluating the potential for watershed restoration to reduce nutrient loading to Upper Klamath Lake, Oregon

USGS Publications Warehouse

McCormick, Paul V.; Campbell, Sharon G.

2007-01-01

A literature review of best management practices to reduce nutrient loading was performed to provide information for resource managers in the Klamath Basin, Oregon. Although BMPs have already been implemented in the watershed, some sense of their effectiveness in reducing phosphorus loading and their cost for installation and maintenance is still lacking. This report discusses both causes of nutrient loading and a wide-variety of BMPs used to treat or reduce causal factors. We specifically focused on cattle grazing as the principal land-use and causal factor for nutrient loading in the Klamath Basin above Upper Klamath Lake, Oregon. Several BMP types, including stream corridor fencing, riparian buffer strips and constructed wetlands, seem to have potential for reducing phosphorus loading that may result from cattle grazing. However, no single BMP is likely to be the most effective in all locations or situations.

Shelter effect efficacy of sand fences: A comparison of systems in a wind tunnel

NASA Astrophysics Data System (ADS)

Wang, Tao; Qu, Jianjun; Ling, Yuquan; Liu, Benli; Xiao, Jianhua

2018-02-01

The Lanzhou-Xinjiang High-speed Railway runs through an expansive wind area in the Gobi Desert and blown-sand disasters are a critical issue affecting its operation. To strengthen the blown-sand disaster shelter systems along the railway, the shelter effects of punching plate and wire mesh fences with approximately equal porosity (48%) were simulated in a wind tunnel. The experimental results showed that the wind velocity was reduced to a higher extent by the punching plate fence than by the wire mesh fence. When a single row of sand fencing was used, the wind velocity reduction coefficient (Rcz) values downwind of the punching plate fence and wire mesh fence reached 71.77% and 39.37%, respectively. When double rows of sand fencing were used, the Rcz values downwind of the punching plate and wire mesh fences were approximately 87.48% and 60.81%, respectively. For the flow field structure on the leeward side of the fencing, the deceleration zone behind the punching plate fence was more pronounced than that behind the wire mesh fence. The vortex zone was not obvious and the reverse flow disappeared for both types of fences, which indicates that the turbulent intensity was small. The sand-trapping efficiency of the wire mesh fence was close to that of punching plate fence. When a single row of sand fencing was set up, the total mass flux density decreased, on average, by 65.85% downwind of the wire mesh fence, and 75.06% downwind of the punching plate fence; when double rows of sand fencing were present, the total mass flux density decreased, on average, by 84.53% downwind of the wire mesh fence and 84.51% downwind of the punching plate fence. In addition, the wind-proof efficiency and the sand-proof efficiency of the punching plate fence and the wire mesh fence decreased with increasing wind velocities. Consequently, punching plate and wire mesh fences may effectively control the sand hazard in the expansive wind area of the Gobi Desert.

Prudent Protomognathus and despotic Leptothorax duloticus: Differential costs of ant slavery

PubMed Central

Hare, James F.; Alloway, Thomas M.

2001-01-01

The concept of ant slavery rests on the untested assumption that slave-making ants impose fitness costs on colonies of the species they raid. We tested that assumption by comparing the summertime seasonal productivity of Leptothorax spp. colonies in field exclosures without slavemakers, with a colony of the obligatory slave-making ant Protomognathus americanus, or with a colony of the obligatory slavemaker Leptothorax duloticus. Leptothorax longispinosus colonies placed in exclosures with P. americanus colonies did not differ significantly in any demographic attribute from colonies in exclosures without slavemakers. By contrast, Leptothorax curvispinosus colonies exposed to L. duloticus experienced significant reductions in dealate queens, workers, and larvae relative to control colonies exclosed without slavemakers. The pronounced difference in the impact of these slavemakers on their host-species populations correlates with differences in the behavior of the slavemakers observed in the laboratory and likely explains why P. americanus is more abundant than L. duloticus in nature. It seems that more advanced social parasites, like anatomical parasites, evolve to minimize their impact on their hosts, and thus can be regarded as “prudent social parasites.” PMID:11572933

Adoption of Stream Fencing Among Dairy Farmers in Four New Zealand Catchments

NASA Astrophysics Data System (ADS)

Bewsell, Denise; Monaghan, Ross M.; Kaine, Geoff

2007-08-01

The effect of dairy farming on water quality in New Zealand streams has been identified as an important environmental issue. Stream fencing, to keep cattle out of streams, is seen as a way to improve water quality. Fencing ensures that cattle cannot defecate in the stream, prevents bank erosion, and protects the aquatic habitat. Stream fencing targets have been set by the dairy industry. In this paper the results of a study to identify the factors influencing dairy farmers’ decisions to adopt stream fencing are outlined. Qualitative methods were used to gather data from 30 dairy farmers in four New Zealand catchments. Results suggest that farm contextual factors influenced farmers’ decision making when considering stream fencing. Farmers were classified into four segments based on their reasons for investing in stream fencing. These reasons were fencing boundaries, fencing for stock control, fencing to protect animal health, and fencing because of pressure to conform to local government guidelines or industry codes of practice. This suggests that adoption may be slow in the absence of on-farm benefits, that promotion of stream fencing needs to be strongly linked to on-farm benefits, and that regulation could play a role in ensuring greater adoption of stream fencing.

Detusking fence-breaker elephants as an approach in human-elephant conflict mitigation.

PubMed

Mutinda, Matthew; Chenge, Geoffrey; Gakuya, Francis; Otiende, Moses; Omondi, Patrick; Kasiki, Samuel; Soriguer, Ramón C; Alasaad, Samer

2014-01-01

Human-elephant conflict (HEC) is a recurring problem that appears wherever the range of elephants and humans overlap. Different methods including the use of electric fences are used worldwide to mitigate this conflict. Nonetheless, elephants learn quickly that their tusks do not conduct electricity and use them to break down fences (fence-breakers). In Lewa Wildlife Conservancy, Kenya, destructive elephants (Loxodonta africana) were monitored between 2010 and 2013. The fence-breaking rate reached four incidents (fence-breaking) per elephant per 100 days. Ten bull males and 57 females were identified as fence-breakers. The bulls were involved in 85.07% and the females in 14.93% of incidents. The Kenya Wildlife Service approved detusking (partial cutting of tusks) in four of the 10 fence-breakers as a way of preventing them from breaking down fences, thereby mitigating HEC in the Conservancy. The result of the detusking was a drastic six-fold reduction in damage to fences (range: 1.67 to 14.5 times less fence-breaking) by the four worst fence-breaker elephants, because with trimmed tusks elephants lack the tools to break down fences. Detusking could not totally eliminate fence destruction because, despite lacking their tools, elephants can still destroy fences using their heads, bodies and trunks, albeit less effectively. On the other hand, apart from inherent aesthetic considerations, the detusking of elephants may have certain negative effects on factors such as elephants' social hierarchies, breeding, mate selection and their access to essential minerals and food. Elephant detusking seems to be effective in drastically reducing fence-breaking incidents, nonetheless its negative effects on behaviour, access to food and its aesthetical consequences still need to be further studied and investigated.

Lesser prairie-chicken fence collision risk across its northern distribution

USGS Publications Warehouse

Robinson, Samantha G.; Haukos, David A.; Plumb, Reid T.; Hagen, Christian A.; Pitman, James C.; Lautenbach, Joseph M.; Sullins, Daniel S.; Kraft, John D.; Lautenbach, Jonathan D.

2016-01-01

Livestock fences have been hypothesized to significantly contribute to mortality of lesser prairie-chickens (Tympanuchus pallidicinctus); however, quantification of mortality due to fence collisions is lacking across their current distribution. Variation in fence density, landscape composition and configuration, and land use could influence collision risk of lesser prairie-chickens. We monitored fences within 3 km of known leks during spring and fall and surveyed for signs of collision occurrence within 20 m of fences in 6 study sites in Kansas and Colorado, USA during 2013 and 2014. We assessed mortality locations of radio-tagged birds (n = 286) for evidence of fence collisions and compared distance to fence relative to random points. Additionally, we quantified locations, propensity, and frequency of fences crossed by lesser prairie-chickens. We tested for landscape and vegetative characteristics that influenced fence-cross propensity and frequency of global positioning system (GPS)-marked birds. A minimum of 12,706 fence crossings occurred by GPS-marked lesser prairie-chickens. We found 3 carcasses and 12 additional possible instances of evidence of collision during >2,800 km of surveyed fences. We found evidence for a single suspected collision based on carcass evidence for 148 mortalities of transmittered birds. Mortality locations of transmittered birds were located at distances from fences 15% farther than expected at random. Our data suggested minimal biological significance and indicated that propensity and frequency of fence crossings were random processes. Lesser prairie-chickens do not appear to be experiencing significant mortality risk due to fence collisions in Kansas and Colorado. Focusing resources on other limiting factors (i.e., habitat quality) has greater potential for impact on population demography than fence marking and removal.

Detusking Fence-Breaker Elephants as an Approach in Human-Elephant Conflict Mitigation

PubMed Central

Mutinda, Matthew; Chenge, Geoffrey; Gakuya, Francis; Otiende, Moses; Omondi, Patrick; Kasiki, Samuel; Soriguer, Ramón C.; Alasaad, Samer

2014-01-01

Background Human-elephant conflict (HEC) is a recurring problem that appears wherever the range of elephants and humans overlap. Different methods including the use of electric fences are used worldwide to mitigate this conflict. Nonetheless, elephants learn quickly that their tusks do not conduct electricity and use them to break down fences (fence-breakers). Methodology/Principal Findings In Lewa Wildlife Conservancy, Kenya, destructive elephants (Loxodonta africana) were monitored between 2010 and 2013. The fence-breaking rate reached four incidents (fence-breaking) per elephant per 100 days. Ten bull males and 57 females were identified as fence-breakers. The bulls were involved in 85.07% and the females in 14.93% of incidents. The Kenya Wildlife Service approved detusking (partial cutting of tusks) in four of the 10 fence-breakers as a way of preventing them from breaking down fences, thereby mitigating HEC in the Conservancy. The result of the detusking was a drastic six-fold reduction in damage to fences (range: 1.67 to 14.5 times less fence-breaking) by the four worst fence-breaker elephants, because with trimmed tusks elephants lack the tools to break down fences. Detusking could not totally eliminate fence destruction because, despite lacking their tools, elephants can still destroy fences using their heads, bodies and trunks, albeit less effectively. On the other hand, apart from inherent aesthetic considerations, the detusking of elephants may have certain negative effects on factors such as elephants' social hierarchies, breeding, mate selection and their access to essential minerals and food. Conclusions Elephant detusking seems to be effective in drastically reducing fence-breaking incidents, nonetheless its negative effects on behaviour, access to food and its aesthetical consequences still need to be further studied and investigated. PMID:24614538

Mediating Water Temperature Increases Due to Livestock and Global Change in High Elevation Meadow Streams of the Golden Trout Wilderness

PubMed Central

Nusslé, Sébastien; Matthews, Kathleen R.; Carlson, Stephanie M.

2015-01-01

Rising temperatures due to climate change are pushing the thermal limits of many species, but how climate warming interacts with other anthropogenic disturbances such as land use remains poorly understood. To understand the interactive effects of climate warming and livestock grazing on water temperature in three high elevation meadow streams in the Golden Trout Wilderness, California, we measured riparian vegetation and monitored water temperature in three meadow streams between 2008 and 2013, including two “resting” meadows and one meadow that is partially grazed. All three meadows have been subject to grazing by cattle and sheep since the 1800s and their streams are home to the imperiled California golden trout (Oncorhynchus mykiss aguabonita). In 1991, a livestock exclosure was constructed in one of the meadows (Mulkey), leaving a portion of stream ungrazed to minimize the negative effects of cattle. In 2001, cattle were removed completely from two other meadows (Big Whitney and Ramshaw), which have been in a “resting” state since that time. Inside the livestock exclosure in Mulkey, we found that riverbank vegetation was both larger and denser than outside the exclosure where cattle were present, resulting in more shaded waters and cooler maximal temperatures inside the exclosure. In addition, between meadows comparisons showed that water temperatures were cooler in the ungrazed meadows compared to the grazed area in the partially grazed meadow. Finally, we found that predicted temperatures under different global warming scenarios were likely to be higher in presence of livestock grazing. Our results highlight that land use can interact with climate change to worsen the local thermal conditions for taxa on the edge and that protecting riparian vegetation is likely to increase the resiliency of these ecosystems to climate change. PMID:26565706

Population structure, persistence, and seasonality of autochthonous Escherichia coli in temperate, coastal forest soil from a Great Lakes watershed

USGS Publications Warehouse

Byappanahalli, M.N.; Whitman, R.L.; Shively, D.A.; Sadowsky, M.J.; Ishii, S.

2006-01-01

The common occurrence of Escherichia coli in temperate soils has previously been reported, however, there are few studies to date to characterize its source, distribution, persistent capability and genetic diversity. In this study, undisturbed, forest soils within six randomly selected 0.5 m2 exclosure plots (covered by netting of 2.3 mm2 mesh size) were monitored from March to October 2003 for E. coli in order to describe its numerical and population characteristics. Culturable E. coli occurred in 88% of the samples collected, with overall mean counts of 16 MPN g-1, ranging from <1 to 1657 (n = 66). Escherichia coli counts did not correlate with substrate moisture content, air, or soil temperatures, suggesting that seasonality were not a strong factor in population density control. Mean E. coli counts in soil samples (n = 60) were significantly higher inside than immediately outside the exclosures; E. coli distribution within the exclosures was patchy. Repetitive extragenic palindromic polymerase chain reaction (Rep-PCR) demonstrated genetic heterogeneity of E. coli within and among exclosure sites, and the soil strains were genetically distinct from animal (E. coli) strains tested (i.e. gulls, terns, deer and most geese). These results suggest that E. coli can occur and persist for extended periods in undisturbed temperate forest soils independent of recent allochthonous input and season, and that the soil E. coli populations formed a cohesive phylogenetic group in comparison to the set of fecal strains with which they were compared. Thus, in assessing E. coli sources within a stream, it is important to differentiate background soil loadings from inputs derived from animal and human fecal contamination. ?? 2005 Society for Applied Microbiology and Blackwell Publishing Ltd.

Mediating Water Temperature Increases Due to Livestock and Global Change in High Elevation Meadow Streams of the Golden Trout Wilderness.

PubMed

Nusslé, Sébastien; Matthews, Kathleen R; Carlson, Stephanie M

2015-01-01

Rising temperatures due to climate change are pushing the thermal limits of many species, but how climate warming interacts with other anthropogenic disturbances such as land use remains poorly understood. To understand the interactive effects of climate warming and livestock grazing on water temperature in three high elevation meadow streams in the Golden Trout Wilderness, California, we measured riparian vegetation and monitored water temperature in three meadow streams between 2008 and 2013, including two "resting" meadows and one meadow that is partially grazed. All three meadows have been subject to grazing by cattle and sheep since the 1800s and their streams are home to the imperiled California golden trout (Oncorhynchus mykiss aguabonita). In 1991, a livestock exclosure was constructed in one of the meadows (Mulkey), leaving a portion of stream ungrazed to minimize the negative effects of cattle. In 2001, cattle were removed completely from two other meadows (Big Whitney and Ramshaw), which have been in a "resting" state since that time. Inside the livestock exclosure in Mulkey, we found that riverbank vegetation was both larger and denser than outside the exclosure where cattle were present, resulting in more shaded waters and cooler maximal temperatures inside the exclosure. In addition, between meadows comparisons showed that water temperatures were cooler in the ungrazed meadows compared to the grazed area in the partially grazed meadow. Finally, we found that predicted temperatures under different global warming scenarios were likely to be higher in presence of livestock grazing. Our results highlight that land use can interact with climate change to worsen the local thermal conditions for taxa on the edge and that protecting riparian vegetation is likely to increase the resiliency of these ecosystems to climate change.

Complex effects of mammalian grazing on extramatrical mycelial biomass in the Scandes forest-tundra ecotone.

PubMed

Vowles, Tage; Lindwall, Frida; Ekblad, Alf; Bahram, Mohammad; Furneaux, Brendan R; Ryberg, Martin; Björk, Robert G

2018-01-01

Mycorrhizal associations are widespread in high-latitude ecosystems and are potentially of great importance for global carbon dynamics. Although large herbivores play a key part in shaping subarctic plant communities, their impact on mycorrhizal dynamics is largely unknown. We measured extramatrical mycelial (EMM) biomass during one growing season in 16-year-old herbivore exclosures and unenclosed control plots (ambient), at three mountain birch forests and two shrub heath sites, in the Scandes forest-tundra ecotone. We also used high-throughput amplicon sequencing for taxonomic identification to investigate differences in fungal species composition. At the birch forest sites, EMM biomass was significantly higher in exclosures (1.36 ± 0.43 g C/m 2 ) than in ambient conditions (0.66 ± 0.17 g C/m 2 ) and was positively influenced by soil thawing degree-days. At the shrub heath sites, there was no significant effect on EMM biomass (exclosures: 0.72 ± 0.09 g C/m 2 ; ambient plots: 1.43 ± 0.94). However, EMM biomass was negatively related to Betula nana abundance, which was greater in exclosures, suggesting that grazing affected EMM biomass positively. We found no significant treatment effects on fungal diversity but the most abundant ectomycorrhizal lineage/cortinarius, showed a near-significant positive effect of herbivore exclusion ( p  = .08), indicating that herbivory also affects fungal community composition. These results suggest that herbivory can influence fungal biomass in highly context-dependent ways in subarctic ecosystems. Considering the importance of root-associated fungi for ecosystem carbon balance, these findings could have far-reaching implications.

Long-term deer exclusion has complex effects on a suburban forest understory

USGS Publications Warehouse

Faison, Edward K.; Foster, David R.; DeStefano, Stephen

2016-01-01

Herbivory by deer is one of the leading biotic disturbances on forest understories (i.e., herbs, small shrubs, and small tree seedlings). A large body of research has reported declines in height, abundance, and reproductive capacity of forbs and woody plants coupled with increases in abundance of graminoids, ferns, and exotic species due to deer herbivory. Less clear is the extent to which (and the direction in which) deer alter herbaceous layer diversity, where much of the plant diversity in a forest occurs. We examined the effect of 15 y of deer exclusion on the understory of a suburban hardwood forest in Connecticut exposed to decades of intensive herbivory by white-tailed deer (Odocoileus virginianus). We compared species richness (at subplot and plot scale), individual species and life form group abundance (% cover), and community composition between grazed and exclosure plots, as well as between mesic and wet soil blocks. Forb cover was more than twice as abundant in exclosure as in grazed plots, whereas sedge (Carex spp.) cover was 28 times more abundant, and exotic species cover generally higher in grazed than in exclosure plots. Native and exotic species richness were both higher in grazed than exclosure plots at the subplot scale, and native herbaceous richness was higher in grazed plots at both spatial scales. In contrast, native shrub richness increased with deer exclusion at the plot scale. Our results suggest that deer exclusion had contrasting effects on species richness, depending on plant life form, but that overall richness of both exotic and native plants declined with deer exclusion. In addition, site heterogeneity remained an important driver of vegetation dynamics even in the midst of high deer densities.

Residential fencing in a metropolitan area and three small towns.

Treesearch

Edwin Kallio; Jerry A. Sesco

1967-01-01

Many types of fences were found on residential lots in the metropolitan-suburban area of St. Louis County, Missouri, and three small towns in southern Illinois. Wire fences predominated. More wooden fences were found on village lots than on city lots. In general, the more expensive homes had the most wooden fencing. Homes over 5 years old had more fencing of all...

Modeling Fence Location and Density at a Regional Scale for Use in Wildlife Management

PubMed Central

Poor, Erin E.; Jakes, Andrew; Loucks, Colby; Suitor, Mike

2014-01-01

Barbed and woven wire fences, common structures across western North America, act as impediments to wildlife movements. In particular, fencing influences pronghorn (Antilocapra americana) daily and seasonal movements, as well as modifying habitat selection. Because of fencing's impacts to pronghorn and other wildlife, it is a potentially important factor in both wildlife movement and habitat selection models. At this time, no geospatial fencing data is available at regional scales. Consequently, we constructed a regional fence model using a series of land tenure assumptions for the Hi-Line region of northern Montana – an area consisting of 13 counties over 103,400 km2. Randomized 3.2 km long transects (n = 738) on both paved and unpaved roads were driven to collect information on habitat, fence densities and fence type. Using GIS, we constructed a fence location and a density model incorporating ownership, size, neighboring parcels, township boundaries and roads. Local knowledge of land ownership and land use assisted in improving the final models. We predict there is greater than 263,300 km of fencing in the Hi-Line region, with a maximum density of 6.8 km of fencing per km2 and mean density of 2.4 km of fencing per km2. Using field data to assess model accuracy, Cohen's Kappa was measured at 0.40. On-the-ground fence modification or removal could be prioritized by identifying high fence densities in critical wildlife areas such as pronghorn migratory pathways or sage grouse lekking habitat. Such novel fence data can assist wildlife and land managers to assess effects of anthropogenic features to wildlife at various scales; which in turn may help conserve declining grassland species and overall ecological functionality. PMID:24416180

Effects of physical disturbance and granivory on establishment of native and alien riparian trees in Colorado, USA

USGS Publications Warehouse

Katz, G.L.; Friedman, J.M.; Beatty, S.W.

2001-01-01

In western North America, the alien Elaeagnus angustifolia L. invades riparian habitats usually dominated by pioneer woody species such as Populus deltoides Marshall ssp. monilifera (Aiton) Eckenwalder. We conducted manipulative field experiments to compare the importance of physical disturbance and granivory for seedling establishment of these two species. We planted seeds of both species in disturbed and undisturbed study plots, and used exclosures, seed dish trials and live-trapping to assess the role of granivory. Seedling establishment of both species was increased by physical disturbance and seeds of both species were subject to granivory. However, the relative importance of these two factors differed between species. For P. deltoides, lack of physical disturbance prevented seedling establishment in uncleared subplots, but granivory did not prevent seedling establishment outside of exclosures. For E. angustifolia, granivory prevented seedling establishment outside of exclosures, but lack of physical disturbance did not prevent establishment in uncleared subplots. The lesser dependence on disturbance may enable E. angustifolia to invade areas characterized by low levels of fluvial disturbance, such as floodplains along regulated rivers, where P. deltoides recruitment does not occur. Populations of granivorous rodents may affect the susceptibility of riparian ecosystems to invasion by E. angustifolia.

Sand fences in the coastal zone: intended and unintended effects.

PubMed

Grafals-Soto, Rosana; Nordstrom, Karl

2009-09-01

Sand-trapping fences modify the character of the coastal landscape and change its spatial structure, image, and meaning. This paper examines the relationship between these changes and fence usage at the municipal level, where most decisions about fence deployment are made. Use of fences in 29 municipalities on the developed coast of New Jersey is examined over a 6-year period. Interviews with municipal officers indicate that wooden slat sand-trapping fences are used primarily to build dunes to provide protection against wave uprush and flooding, but they are also used to control pedestrian traffic and demarcate territory. These uses result in changes in landforms and habitats. An aerial video inventory of fences taken in 2002 indicates that 82% of the shoreline had fences and 72% had dunes. Single and double straight fence rows are the most commonly used. Fences are often built to accomplish a specific primary purpose, but they can cause many different and often unanticipated changes to the landscape. The effects of a sand fence change through time as the initial structure traps sand, creates a dune that is colonized by vegetation, and becomes integrated into the environment by increasing topographic variability and aesthetic and habitat value. Sand fences can be made more compatible with natural processes by not placing them in locations where sources of wind blown sand are restricted or in unnatural shore perpendicular orientations. Symbolic fences are less expensive, are easy to replace when damaged, are less visually intrusive, and can be used for controlling pedestrian access.

Large herbivore grazing affects the vegetation structure and greenhouse gas balance in a high arctic mire

NASA Astrophysics Data System (ADS)

Falk, Julie Maria; Schmidt, Niels Martin; Christensen, Torben R.; Ström, Lena

2015-04-01

Herbivory is an important part of most ecosystems and affects the ecosystems’ carbon balance both directly and indirectly. Little is known about herbivory and its impact on the carbon balance in high arctic mire ecosystems. We hypothesized that trampling and grazing by large herbivores influences the vegetation density and composition and thereby also the carbon balance. In 2010, we established fenced exclosures in high arctic Greenland to prevent muskoxen (Ovibos moschatus) from grazing. During the growing seasons of 2011 to 2013 we measured CO2 and CH4 fluxes in these ungrazed blocks and compared them to blocks subjected to natural grazing. Additionally, we measured depth of the water table and active layer, soil temperature, and in 2011 and 2013 an inventory of the vegetation density and composition were made. In 2013 a significant decrease in total number of vascular plant (33-44%) and Eriophorum scheuchzeri (51-53%) tillers were found in ungrazed plots, the moss-layer and amount of litter had also increased substantially in these plots. This resulted in a significant decrease in net ecosystem uptake of CO2 (47%) and likewise a decrease in CH4 emission (44%) in ungrazed plots in 2013. While the future of the muskoxen in a changing arctic is unknown, this experiment points to a potentially large effect of large herbivores on the carbon balance in natural Arctic ecosystems. It thus sheds light on the importance of grazing mammals, and hence adds to our understanding of natural ecosystem greenhouse gas balance in the past and in the future.

Natural remediation of an unremediated soil twelve years after a mine accident: trace element mobility and plant composition.

PubMed

Burgos, Pilar; Madejón, Paula; Madejón, Engracia; Girón, Ignacio; Cabrera, Francisco; Murillo, José Manuel

2013-01-15

The long-term influence of a mine spill in soil was studied 12 years after the Aznalcóllar accident. Soils where the pyritic sludge was not removed, a fenced plot established for research purposes (2000 m(2)) and soils where the process of remediation was accomplished successfully were sampled and studied in detail. Soils were characterized at different depths, down to 100 cm depth, determining chemical parameters and total concentrations of major and trace elements. Moreover plants colonizing remediated (RE) and non remediated (NRE) soils were also analysed attending their potential risk for herbivores. Strong acidification was observed in the NRE soil except in surface (0-10 cm). The progressive colonization of natural vegetation, more than 90% of the fenced plot covered by plants, could facilitate this increased pH values in the top soil (pH 6). In the NRE soil, the successive oxidation and hydrolysis of sulphide in the deposited sludge on the surface after the accident resulted in a re-dissolution of the most mobile element (Cd, Cu and Zn) and a penetration to deeper layers. Trace element concentrations in plants growing in the NRE soil showed normal contents for higher plants and tolerable for livestock. Nitrogen and mineral nutrients were of the same order in both soils, and also normal for high plants and adequate for animal nutrition. Despite of the natural remediation of the NRE soil, results demonstrate that the remediation tasks carried out in all the area, the Guadiamar Green Corridor at present, were necessary to avoid the leaching of the most mobile elements and minimize the risk of contamination of groundwater sources, many of them close to the Doñana National Park. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of sand fences on coastal dune vegetation distribution

NASA Astrophysics Data System (ADS)

Grafals-Soto, Rosana

2012-04-01

Sand fences are important human adjustments modifying the morphology of developed shores. The effects of sand fences on sediment transport and deposition in their initial stages have been well studied, but little is known about the effect of deteriorated sand fences that have become partially buried low scale barriers within the dune, potentially benefiting vegetation growth by protecting it from onshore stress. Data on vegetation, topography and fence characteristics were gathered at three dune sites in Ocean City, New Jersey on September 2007 and March 2008 to evaluate the effect of fences within the dune on vegetation distribution. Variables include: distance landward of dune toe, degree of sheltering from onshore stressors, net change in surface elevation (deposition or erosion), vegetation diversity and density, presence of remnant fence, and distance landward of fence. Results for the studied environment reveal that 1) vegetation diversity or density does not increase near remnant fences because most remnants are lower than average vegetation height and can not provide shelter; but 2) vegetation distribution is related to topographic variables, such as degree of sheltering, that are most likely the result of sand accretion caused by fence deployment. Fence deployment that prioritizes the creation of topographically diverse dunes within a restricted space may increase the diversity and density of the vegetation, and the resilience and value of developed dunes. Managers should consider the benefits of using sand fences on appropriately wide beaches to create a protective dune that is also diverse, functional and better able to adapt to change.

Controlling Within-Field Sheep Movement Using Virtual Fencing.

PubMed

Marini, Danila; Llewellyn, Rick; Belson, Sue; Lee, Caroline

2018-02-26

Virtual fencing has the potential to greatly improve livestock movement, grazing efficiency, and land management by farmers; however, relatively little work has been done to test the potential of virtual fencing with sheep. Commercial dog training equipment, comprising of a collar and GPS hand-held unit were used to implement a virtual fence in a commercial setting. Six, 5-6 year-old Merino wethers, which were naïve to virtual fencing were GPS tracked for their use of a paddock (80 × 20 m) throughout the experiment. The virtual fence was effective at preventing a small group of sheep from entering the exclusion zone. The probability of a sheep receiving an electrical stimulus following an audio cue was low (19%), and declined over the testing period. It took an average of eight interactions with the fence for an association to be made between the audio and stimulus cue, with all of the animals responding to the audio alone by the third day. Following the removal of the virtual fence, sheep were willing to cross the previous location of the virtual fence after 30 min of being in the paddock. This is an important aspect in the implementation of virtual fencing as a grazing management tool and further enforces that the sheep in this study were able to associate the audio with the virtual fence and not the physical location itself.

Ecological evaluation of the abundance and effects of elk herbivory in Rocky Mountain National Park, Colorado, 1994-1999

USGS Publications Warehouse

Singer, Francis J.; Zeigenfuss, Linda C.

2002-01-01

Several National Park Service units in the Intermountain region possess a number of closely related management needs relative to the abundance of wild ungulates and their herbivory effects on plants and ecosystem processes. In 1993, the then National Biological Service (NBS) - now U.S. Geological Survey, Biological Resources Discipline (USGS, BRD)­ initiated a series of research studies in four park units in the Intermountain West., into the abundance and effects of ungulates on park ecosystems. Each of these parks received a number of similar research study elements including: (a) a number of new ungulate grazing exclosures (n = 12-21 exclosures per park); (b) aerial survey sightability models to estimate population sizes of ungulates; (e) measures of biomass production and consumption rates near the exclosures and across the landscape; (d) studies of the effects of the grazing on plant abundance, species diversity, and ecosystem effects; and (e) computer model simulations (SAVANNA) of the effects on the ecosystem and plant resources of different ungulate management scenarios. One park unit, Rocky Mountain National Park, Colorado, received funding from the U.S. Geological Survey (USGS, BRD) and parallel funding from NPS for an intensive research study of the effects of elk on the park ecosystems.

Experimental defaunation of terrestrial mammalian herbivores alters tropical rainforest understorey diversity

PubMed Central

Camargo-Sanabria, Angela A.; Mendoza, Eduardo; Guevara, Roger; Martínez-Ramos, Miguel; Dirzo, Rodolfo

2015-01-01

It has been suggested that tropical defaunation may unleash community-wide cascading effects, leading to reductions in plant diversity. However, experimental evidence establishing cause–effect relationships thereof is poor. Through a 5 year exclosure experiment, we tested the hypothesis that mammalian defaunation affects tree seedling/sapling community dynamics leading to reductions in understorey plant diversity. We established plot triplets (n = 25) representing three defaunation contexts: terrestrial-mammal exclosure (TE), medium/large mammal exclosure (PE) and open access controls (C). Seedlings/saplings 30–100 cm tall were marked and identified within each of these plots and re-censused three times to record survival and recruitment. In the periods 2010–2011 and 2011–2013, survival was greater in PE than in C plots and recruitment was higher in TE plots than in C plots. Overall, seedling density increased by 61% in TE plots and 23% in PE plots, whereas it decreased by 5% in C plots. Common species highly consumed by mammals (e.g. Brosimum alicastrum and Ampelocera hottlei) increased in their abundance in TE plots. Rarefaction curves showed that species diversity decreased in TE plots from 2008 to 2013, whereas it remained similar for C plots. Given the prevalence of tropical defaunation, we posit this is an anthropogenic effect threatening the maintenance of tropical forest diversity. PMID:25540281

Fences and grazing management in northern Namibia

NASA Astrophysics Data System (ADS)

Prudat, Brice; Bloemertz, Lena; Kuhn, Nikolaus J.

2016-04-01

Since Namibian independence, many fences have been erected in the communal land of the Ohangwena region in northern Namibia. Most fencing issues discussed so far in the region concern large-scale fencing of communal land by the new Namibian elite. Rarely discussed are the fences erected around small-scale farmers' parcels. This paper will discuss the impact of such increased small-scale fencing activities in northern Namibia. Fencing of land has different functions, including protection of fields against livestock and securing property rights. However, not all community members can afford the monetary and labor costs involved. In the annual agricultural cycle of the study area, livestock is left un-herded after the harvest of most crops. They can then feed on available crop remains and grass on the fields. The livestock then freely utilizes unfenced and unprotected land. This system has the advantage to accelerate crop degradation and fertilize the soils. However, by erecting efficient fences, the new middle-class community members concentrate fertility in their own field, thereby degrading agricultural soils of poorer farmers. Potentially, such small-scale fencing of land has therefore an impact on sol quality and thus fosters degradation of unfenced cropland. By using fences as features to determine the limits of the new land rights, the ongoing Communal Land Reform may not only promote the erection of fences, but may also have a negative impact on soil quality and potentially food security of small-scale farmers without cattle.

Multiple browsers structure tree recruitment in logged temperate forests

USGS Publications Warehouse

Faison, Edward K.; DeStefano, Stephen; Foster, David R.; Rapp, Joshua M.; Compton, Justin A.

2016-01-01

Historical extirpations have resulted in depauperate large herbivore assemblages in many northern forests. In eastern North America, most forests are inhabited by a single wild ungulate species, white-tailed deer (Odocoileus virginianus), and relationships between deer densities and impacts on forest regeneration are correspondingly well documented. Recent recolonizations by moose (Alces americanus) in northeastern regions complicate established deer density thresholds and predictions of browsing impacts on forest dynamics because size and foraging differences between the two animals suggest a lack of functional redundancy. We asked to what extent low densities of deer + moose would structure forest communities differently from that of low densities of deer in recently logged patch cuts of Massachusetts, USA. In each site, a randomized block with three treatment levels of large herbivores–no-ungulates (full exclosure), deer (partial exclosure), and deer + moose (control) was established. After 6–7 years, deer + moose reduced stem densities and basal area by 2-3-fold, Prunus pensylvanica and Quercus spp. recruitment by 3–6 fold, and species richness by 1.7 species (19%). In contrast, in the partial exclosures, deer had non-significant effects on stem density, basal area, and species composition, but significantly reduced species richness by 2.5 species on average (28%). Deer browsing in the partial exclosure was more selective than deer + moose browsing together, perhaps contributing to the decline in species richness in the former treatment and the lack of additional decline in the latter. Moose used the control plots at roughly the same frequency as deer (as determined by remote camera traps), suggesting that the much larger moose was the dominant browser species in terms of animal biomass in these cuts. A lack of functional redundancy with respect to foraging behavior between sympatric large herbivores may explain combined browsing effects that were both large and complex.

Disturbance of the inclined inserting-type sand fence to wind-sand flow fields and its sand control characteristics

NASA Astrophysics Data System (ADS)

Cheng, Jian-jun; Lei, Jia-qiang; Li, Sheng-yu; Wang, Hai-feng

2016-06-01

The inclined inserting-type sand fence is a novel sand retaining wall adopted along the Lanxin High-Speed Railway II in Xinjiang for controlling and blocking sand movement. To verify the effectiveness of the new fence structure for sand prevention, a wind tunnel test was used for flow field test simulation of the sand fence. The results indicate that the inclined inserting-type sand fence was able to deflect the flow of the sand and was able to easily form an upward slant acceleration zone on the leeward side of the sand fence. As shown by the percentage change in sand collection rates on the windward side and the leeward side of the sand fence, the sand flux per unit area at 4 m height in the slant upward direction increased on the leeward side of the inclined inserting-type sand fence. By comparing the flow fields, this site is an acceleration zone, which also reaffirms the correspondence of wind-sand flow fields with the spatial distribution characteristic of the wind-carried sand motion. The field sand collection data indicates that under the effects of the inclined inserting-type sand fence, the sandy air currents passing in front and behind the sand fence not only changed in quality, but the grain composition and particle size also significantly changed, suggesting that the inclined inserting-type sand fence has a sorting and filtering effect on the sandy air currents that passed through. The fence retained coarse particulates on the windward side and fine particulates within the shade of the wind on the leeward side.

Defaunation affects Astrocaryum gratum (Arecales: Arecaceae) seed survivorship in a sub-montane tropical forest.

PubMed

Aliaga-Rossel, Enzo; Manuel Fragoso, Jos

2015-03-01

Animal-plant interactions in Neotropical forests are complex processes. Within these processes, mid- to large-sized mammals consume fruits and seeds from several species; however, because of their size these mammals are overhunted, resulting in defaunated forests. Our objective was to evaluate and compare seed removal and survivorship in a forest with no hunting, a forest with moderate or reduced hunting, and a forest with higher hunting pressure. We examined the interaction between Astrocaryum gratum and white lipped peccary (Tayassu pecari) to tease apart the defaunation process. To isolate and evaluate mammal seed removal rates and to identify the causes of mortality on Agratum, under the three different hunting pressures forests, we used exclosures in each one. In four different forest-patches for each forest, we positioned a block-treatment consisting of three exclosures (total exclusion, peccary exclusion, and control), randomly distributed 5m apart and the block-treatments spaced 50-75 m apart from one another. We established 15 treatments in total for each patch (5 blocks per patch). There were 20 blocks within each forest type. For total exclusion, all vertebrates were excluded using galvanized wire mesh exclosures. The second, the peccary exclusion, was designed to stop peccaries from entering treatment units, providing access only to small vertebrates; larger mammals were able to access the treatment unit by reaching over the sides and the open top; finally, the Control allowed full access for all mammals. Fresh A. gratum fruits were collected from the forest floor under different adult trees throughout the study area. In each exclosure treatment, twenty Agratum seeds were placed, and their removal was recorded. In total, 3 600 seeds were analyzed. Seed survival was lower in unhunted forest compared to areas with moderate hunting and forest with a higher hunt pressure, supporting the hypothesis of the importance of mammals in seed removal. From the initial 400 seeds left for each control exclosure in each type of forest, there was a significant difference between the seed removal; 1.75% seeds in the unhunted forest remained; 43.5% in the moderately hunted forest, and 48.5% in hunted forest. The main cause of seed mortality was white lipped peccaries; while in the forests without them, the main removal was caused by rodents and a higher insect infection was observed in the heavily hunted forest. Our results indicated that defaunation affects seed survivorship.

Assessment and placement of living snow fences to reduce highway maintenance costs and improve safety (living snow fences).

DOT National Transportation Integrated Search

2015-05-01

Living snow fences (LSF) are designed plantings of trees and/or shrubs and native grasses along highways, roads : and ditches that create a vegetative buffer that traps and controls blowing and drifting snow. These strategically : placed fences have ...

Community Friendship Fence Mural

ERIC Educational Resources Information Center

Gurny, Helen Graham

2008-01-01

The author had just begun Ann Johnson's "Friendship Fence" lesson from the February 2007 issue of "SchoolArts" with her third graders. In this lesson, students created self-portraits on individual fence pickets that were then combined to make a fence. In this article, the author describes how this idea was applied to the wall…

Straight-line drift fences and pitfall traps

USGS Publications Warehouse

Corn, Paul Stephen

1994-01-01

Straight-line drift fences typically are short barriers (5-15 m) that direct animals traveling on the substrate surface into traps places at the ends of or beside the barriers. Traps (described below) can be pitfalls, funnel traps, or a combination of the two. Drift fences with pitfall or funnel traps and pitfall traps without fences are used commonly to inventory and monitor populations of amphibians and reptiles. For example, 9 of 17 field studies reported for management of terrestrial vertebrates (Sarzo et al. 1988) used these techniques to sample amphibians. Drift fences with pitfall traps can be used to determine species richness at a site and to detect the presence of rare species. They also can yield data on relative abundances and habitat use of selected species. Pitfall traps arrayed in a grid without fences can also be used to study the population ecology and habitat use of selected species. Population density can be estimated with this latter technique if used in conjunction with mark-recapture techniques (see Chapter 8). Drift fence arrays or pitfall grids can be left in place for long-term monitoring. In this section, I discuss the use of this technique to obtain data on amphibians away from breeding ponds. Use of drift fences and traps to monitory amphibian activity at breeding ponds is discussed in the section "Drift Fences Encircling Breeding Sits", below (technique 9). Some materials and procedures are common to both techniques. Investigators contemplating the use of drift fences and traps in any context should read both accounts.

Wild Sri Lankan elephants retreat from the sound of disturbed Asian honey bees.

PubMed

King, Lucy; Pardo, Michael; Weerathunga, Sameera; Kumara, T V; Jayasena, Nilmini; Soltis, Joseph; de Silva, Shermin

2018-01-22

Asian elephants (Elephas maximus) are threatened primarily by habitat loss and human-elephant conflict. In addition to establishing protected areas and corridors for wildlife, empowering farmers to protect their crops is crucial for Asian elephant conservation [1,2]. Elephants can habituate to artificial deterrents, hence natural biological alternatives are of great interest [2,3]. African elephants (Loxodonta africana) avoid African honey bees (Apis mellifera scutellata), inspiring 'beehive fences' as a successful means of small-scale crop protection [4,5]. Here, we used a recording of a disturbed hive of cavity-dwelling Asian honey bees (Apis cerana indica) and conducted sound playbacks to 120 wild elephants in 28 different groups resting under trees in Uda Walawe National Park in Sri Lanka. Elephants responded by moving significantly further away from their resting site in bee playback trials compared to controls. Elephants also increased vocalization rates, as well as investigative and reassurance behaviours in response to bee sounds, but did not display dusting or headshaking behaviour. Copyright © 2017 Elsevier Ltd. All rights reserved.

Educational outreach and impacts of white-tailed deer browse on native and invasive plants at the Crooked Creek Environmental Learning Center, Armstrong County, Pennsylvania

NASA Astrophysics Data System (ADS)

Lindsay, Lisa O.

Overabundance of deer can assist the intrusion of invasive plants through browse, leading to homogenization of plant communities. Public attitudes towards native and invasive plant species and white-tailed deer browse related to personal experiences, can be changed through education focusing public awareness of ramifications of deer browse on native and invasive plants. I developed an interactive, interpretive Self-Guided Walking Tour brochure of the "You Can Trail" to provide an educational outreach program for visitors of Crooked Creek Environmental Learning Center that includes ecologically important native and invasive plants species from my investigation. This research study focuses on the overall abundance of native and invasive plant species once Odocoileus virginianus have been removed from the landscape during collection periods in June and September 2013 from exclosure and access plots that were maintained for seven years. Similarity of abundance were found in native and invasive abundance of forbs, bushes and percentage of ground cover. Differences included native bush volume being greater than invasive bush volume in the access plot in June with opposing results in the exclosure plot, being greater in invasive bush volume. However, in September, native and invasive bush volume was similar within the exclosure plot, while invasive bush volume decreased in the access plot. Invasive vines recorded in the June access plot were absent in the September collection period.

Experimental defaunation of terrestrial mammalian herbivores alters tropical rainforest understorey diversity.

PubMed

Camargo-Sanabria, Angela A; Mendoza, Eduardo; Guevara, Roger; Martínez-Ramos, Miguel; Dirzo, Rodolfo

2015-02-07

It has been suggested that tropical defaunation may unleash community-wide cascading effects, leading to reductions in plant diversity. However, experimental evidence establishing cause-effect relationships thereof is poor. Through a 5 year exclosure experiment, we tested the hypothesis that mammalian defaunation affects tree seedling/sapling community dynamics leading to reductions in understorey plant diversity. We established plot triplets (n = 25) representing three defaunation contexts: terrestrial-mammal exclosure (TE), medium/large mammal exclosure (PE) and open access controls (C). Seedlings/saplings 30-100 cm tall were marked and identified within each of these plots and re-censused three times to record survival and recruitment. In the periods 2010-2011 and 2011-2013, survival was greater in PE than in C plots and recruitment was higher in TE plots than in C plots. Overall, seedling density increased by 61% in TE plots and 23% in PE plots, whereas it decreased by 5% in C plots. Common species highly consumed by mammals (e.g. Brosimum alicastrum and Ampelocera hottlei) increased in their abundance in TE plots. Rarefaction curves showed that species diversity decreased in TE plots from 2008 to 2013, whereas it remained similar for C plots. Given the prevalence of tropical defaunation, we posit this is an anthropogenic effect threatening the maintenance of tropical forest diversity. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Combining paleo-data and modern exclosure experiments to assess the impact of megafauna extinctions on woody vegetation

PubMed Central

Bakker, Elisabeth S.; Gill, Jacquelyn L.; Johnson, Christopher N.; Vera, Frans W. M.; Sandom, Christopher J.; Asner, Gregory P.; Svenning, Jens-Christian

2016-01-01

Until recently in Earth history, very large herbivores (mammoths, ground sloths, diprotodons, and many others) occurred in most of the World’s terrestrial ecosystems, but the majority have gone extinct as part of the late-Quaternary extinctions. How has this large-scale removal of large herbivores affected landscape structure and ecosystem functioning? In this review, we combine paleo-data with information from modern exclosure experiments to assess the impact of large herbivores (and their disappearance) on woody species, landscape structure, and ecosystem functions. In modern landscapes characterized by intense herbivory, woody plants can persist by defending themselves or by association with defended species, can persist by growing in places that are physically inaccessible to herbivores, or can persist where high predator activity limits foraging by herbivores. At the landscape scale, different herbivore densities and assemblages may result in dynamic gradients in woody cover. The late-Quaternary extinctions were natural experiments in large-herbivore removal; the paleoecological record shows evidence of widespread changes in community composition and ecosystem structure and function, consistent with modern exclosure experiments. We propose a conceptual framework that describes the impact of large herbivores on woody plant abundance mediated by herbivore diversity and density, predicting that herbivore suppression of woody plants is strongest where herbivore diversity is high. We conclude that the decline of large herbivores induces major alterations in landscape structure and ecosystem functions. PMID:26504223

Combining paleo-data and modern exclosure experiments to assess the impact of megafauna extinctions on woody vegetation.

PubMed

Bakker, Elisabeth S; Gill, Jacquelyn L; Johnson, Christopher N; Vera, Frans W M; Sandom, Christopher J; Asner, Gregory P; Svenning, Jens-Christian

2016-01-26

Until recently in Earth history, very large herbivores (mammoths, ground sloths, diprotodons, and many others) occurred in most of the World's terrestrial ecosystems, but the majority have gone extinct as part of the late-Quaternary extinctions. How has this large-scale removal of large herbivores affected landscape structure and ecosystem functioning? In this review, we combine paleo-data with information from modern exclosure experiments to assess the impact of large herbivores (and their disappearance) on woody species, landscape structure, and ecosystem functions. In modern landscapes characterized by intense herbivory, woody plants can persist by defending themselves or by association with defended species, can persist by growing in places that are physically inaccessible to herbivores, or can persist where high predator activity limits foraging by herbivores. At the landscape scale, different herbivore densities and assemblages may result in dynamic gradients in woody cover. The late-Quaternary extinctions were natural experiments in large-herbivore removal; the paleoecological record shows evidence of widespread changes in community composition and ecosystem structure and function, consistent with modern exclosure experiments. We propose a conceptual framework that describes the impact of large herbivores on woody plant abundance mediated by herbivore diversity and density, predicting that herbivore suppression of woody plants is strongest where herbivore diversity is high. We conclude that the decline of large herbivores induces major alterations in landscape structure and ecosystem functions.

Trajectories of saltating sand particles behind a porous fence

NASA Astrophysics Data System (ADS)

Zhang, Ning; Lee, Sang Joon; Chen, Ting-Guo

2015-01-01

Trajectories of aeolian sand particles behind a porous wind fence embedded in a simulated atmospheric boundary layer were visualized experimentally, to investigate the shelter effect of the fence on sand saltation. Two sand samples, one collected from a beach (d = 250 μm) and the other from a desert (d = 100 μm), were tested in comparison with the previous studies of a 'no-fence' case. A wind fence (ε = 38.5%) was installed on a flat sand bed filled with each sand sample. A high-speed photography technique and the particle tracking velocimetry (PTV) method were employed to reconstruct the trajectories of particles saltating behind the fence. The collision processes of these sand particles were analyzed, momentum and kinetic energy transfer between saltating particles and ground surface were also investigated. In the wake region, probability density distributions of the impact velocities agree well with the pattern of no-fence case, and can be explained by a log-normal law. The horizontal component of impact velocity for the beach sand is decreased by about 54%, and about 76% for the desert sand. Vertical restitution coefficients of bouncing particles are smaller than 1.0 due to the presence of the wind fence. The saltating particles lose a large proportion of their energy during the collision process. These results illustrate that the porous wind fence effectively abates the further evolution of saltating sand particles.

Effectiveness of electric deer fences to protect planted seedlings in Pennsylvania

Treesearch

D.W. George; T.W. Bowersox; L.H. McCormick

1991-01-01

Electric fences are used in Pennsylvania following a timber harvest to reduce deer browse on natural regeneration. In 1984, five-strand electric deer fences were constructed around two central Pennsylvania clearcuts. Northern red oak, white ash, white pine, and yellow-poplar seedlings were planted inside each fenced clearcut area in 1984 and 1985. One-half of the 1280...

Conserving large populations of lions - the argument for fences has holes.

PubMed

Creel, S; Becker, M S; Durant, S M; M'Soka, J; Matandiko, W; Dickman, A J; Christianson, D; Dröge, E; Mweetwa, T; Pettorelli, N; Rosenblatt, E; Schuette, P; Woodroffe, R; Bashir, S; Beudels-Jamar, R C; Blake, S; Borner, M; Breitenmoser, C; Broekhuis, F; Cozzi, G; Davenport, T R B; Deutsch, J; Dollar, L; Dolrenry, S; Douglas-Hamilton, I; Fitzherbert, E; Foley, C; Hazzah, L; Henschel, P; Hilborn, R; Hopcraft, J G C; Ikanda, D; Jacobson, A; Joubert, B; Joubert, D; Kelly, M S; Lichtenfeld, L; Mace, G M; Milanzi, J; Mitchell, N; Msuha, M; Muir, R; Nyahongo, J; Pimm, S; Purchase, G; Schenck, C; Sillero-Zubiri, C; Sinclair, A R E; Songorwa, A N; Stanley-Price, M; Tehou, C A; Trout, C; Wall, J; Wittemyer, G; Zimmermann, A

2013-11-01

Packer et al. reported that fenced lion populations attain densities closer to carrying capacity than unfenced populations. However, fenced populations are often maintained above carrying capacity, and most are small. Many more lions are conserved per dollar invested in unfenced ecosystems, which avoid the ecological and economic costs of fencing. © 2013 John Wiley & Sons Ltd/CNRS.

Avian and amphibian use of fenced and unfenced stock ponds in northeastern Oregon forests.

Treesearch

Evelyn L. Bull; Jerry W. Deal; Janet E. Hohmann

2001-01-01

The abundance of birds and amphibian larvae was compared between fenced and unfenced stock ponds in 1993 to determine if fencing improved the habitat for these species in northeastern Oregon. Stock ponds that were fenced had significantly higher densities of bird species, guilds, and taxonomic groups than stock ponds that were unfenced. No differences in the relative...

Farmers, Ranchers, and the Railroad: The Evolution of Fence Law in the Great Plains, 1865-1900

ERIC Educational Resources Information Center

Kawashima, Yasuhide

2010-01-01

This article is divided into three parts. The first examines specific fencing policies in Kansas, Nebraska, and other Plains states, highlighting the transformation from the "fence-out" to "fence-in" (herd laws) policies. The second part discusses the coming of the railroads to the Great Plains and the farmers and the ranchers…

Minimizing species extinctions through strategic planning for conservation fencing.

PubMed

Ringma, Jeremy L; Wintle, Brendan; Fuller, Richard A; Fisher, Diana; Bode, Michael

2017-10-01

Conservation fences are an increasingly common management action, particularly for species threatened by invasive predators. However, unlike many conservation actions, fence networks are expanding in an unsystematic manner, generally as a reaction to local funding opportunities or threats. We conducted a gap analysis of Australia's large predator-exclusion fence network by examining translocation of Australian mammals relative to their extinction risk. To address gaps identified in species representation, we devised a systematic prioritization method for expanding the conservation fence network that explicitly incorporated population viability analysis and minimized expected species' extinctions. The approach was applied to New South Wales, Australia, where the state government intends to expand the existing conservation fence network. Existing protection of species in fenced areas was highly uneven; 67% of predator-sensitive species were unrepresented in the fence network. Our systematic prioritization yielded substantial efficiencies in that it reduced expected number of species extinctions up to 17 times more effectively than ad hoc approaches. The outcome illustrates the importance of governance in coordinating management action when multiple projects have similar objectives and rely on systematic methods rather than expanding networks opportunistically. © 2017 Society for Conservation Biology.

Influence of groundwater extraction on river flows and the surrounding ecosystem

NASA Astrophysics Data System (ADS)

Belova, Anna

2010-05-01

Influence of groundwater extraction on river flows and the surrounding ecosystem. Change of hydro-geological conditions and the conditions of environment connected with them? One of the most adverse consequences of the large centralised operation of underground waters coastal (riverine) water fences. Such situation is predicted on the Permilovsky deposit reconnoitered for water supply of Arkhangelsk. The projected water fence was planned in a valley of the river of Vajmugi on its left coast. The predesigns spent on hydrogeodynamic of model of a deposit, show that as a result of operation of underground waters the damage to a drain of the river Vajmuga approximately equal дебиту of a water fence that leads to a considerable shallowing of the river, especially during its periods маловодности, up to a drain total disappearance on a water fence site is formed. On the average, on territories of a deposit expenses of the river concerning natural state can be reduced more than to 50 %. Reduction of a river drain will lead to considerable negative consequences in environment, including: - changes in surface runoff, reduced groundwater levels, inhibit vegetation and changes in plant communities, draining wetlands, changing soil moisture conditions, a decrease of spring runoff, damage to forestry; - earth's surface subsidence, damage to streets and roads, buildings, structures and communications, drainage wells, the development of karst processes and suffosion; - the formation of deep depressions, capturing several zones of water exchange, which could lead to mixing of water of different chemical composition and mineralization of the runoff into surface water bodies, increase the nitrogen content in groundwater; - discontinuity separating the layers and the increased vulnerability of groundwater and surface water, the action of man-made agents. The aim of this study was a preliminary study of alternative schemes of exploitation of underground water deposits, in which damage to river flow, essentially inevitable, will be minimized. The alternative scheme provides reduction of productivity of the basic water fence during the periods critical aquaticity. During these periods, for preservation of volume of water giving, the additional (compensatory) water fence is entered into operation. Settlement remoteness compensatory water fence is defined by a condition that for rather short-term period (in low flow) water fence works, its hydrodynamic influence did not reach the river and basic water fence. At the same time, during the periods high aquaticity when compensatory water fence does not work, stocks водоносного horizon on the area of its depression should be restored completely. For use of this scheme it is necessary to define the periods of an inadmissible damage to a drain during which reduction discharge of the basic water fence both use compensatory water fence, and operational loading basic water fence and compensatory water fence during the periods of their teamwork is required. Is minimum admissible expense for the given territory should be defined after the special ecological analysis. For tentative estimations 2 variants are considered: 1) in the river of Vajmuga, in a water fence alignment, the expense not below 25 % from minimum low-flow natural size all-the-year-round should remain; 2) on a water fence site in the river the expense not below 25 % from mid-annual size should remain. For both variants the periods of reduction of productivity of the basic water fence are proved and introductions in operation of the compensatory water fence. Have been calculated values of reduction of productivity of the basic water fence, its new discharge and as discharge of the compensatory water fence. It is received that discharge of the basic water fence should be reduced to 35 and 37 % for the first and second settlement variants accordingly. The quantity of knots of chinks and their arrangement stole up in the course of modelling. It is as a result received that at use of the given scheme, the drain of the river of Vajmuga does not reach values below the critical. On model it is received that at work of the compensatory water fence the funnel is formed local depression, and settlement falls of levels do not reach basic water fence and the rivers. It means that operation of the compensatory water fence does not influence a river drain and is provided drawdown capacities aquifer horizon. Result of the performed work was the proof of basic possibility of the alternative scheme of operation of underground waters on a deposit at which change of a drain of the rivers will have admissible limits and will not cause essential changes of ecological conditions of territory as a whole.

Simple-Cubic Carbon Frameworks with Atomically Dispersed Iron Dopants toward High-Efficiency Oxygen Reduction.

PubMed

Wang, Biwei; Wang, Xinxia; Zou, Jinxiang; Yan, Yancui; Xie, Songhai; Hu, Guangzhi; Li, Yanguang; Dong, Angang

2017-03-08

Iron and nitrogen codoped carbons (Fe-N-C) have attracted increasingly greater attention as electrocatalysts for oxygen reduction reaction (ORR). Although challenging, the synthesis of Fe-N-C catalysts with highly dispersed and fully exposed active sites is of critical importance for improving the ORR activity. Here, we report a new type of graphitic Fe-N-C catalysts featuring numerous Fe single atoms anchored on a three-dimensional simple-cubic carbon framework. The Fe-N-C catalyst, derived from self-assembled Fe 3 O 4 nanocube superlattices, was prepared by in situ ligand carbonization followed by acid etching and ammonia activation. Benefiting from its homogeneously dispersed and fully accessible active sites, highly graphitic nature, and enhanced mass transport, our Fe-N-C catalyst outperformed Pt/C and many previously reported Fe-N-C catalysts for ORR. Furthermore, when used for constructing the cathode for zinc-air batteries, our Fe-N-C catalyst exhibited current and power densities comparable to those of the state-of-the-art Pt/C catalyst.

Technology for Range Security

DTIC Science & Technology

2005-06-01

friction- generated charge transfer between the inner and outer portions of a cable attached to the fence ( triboelectric ), by means of a charge transfer...helpful technical reviews of Paul Loechl, ERDC- CERL, and Joyce Nagle, ERDC-CRREL. This report was prepared under the general supervision of Dr...detection systems (IDSs) are designed to generate alarms when they sense human activity. IDSs attached to a fence (fence-mounted) respond to fence

Expansion of deciduous tall shrubs but not evergreen dwarf shrubs inhibited by reindeer in Scandes mountain range.

PubMed

Vowles, Tage; Gunnarsson, Bengt; Molau, Ulf; Hickler, Thomas; Klemedtsson, Leif; Björk, Robert G

2017-11-01

One of the most palpable effects of warming in Arctic ecosystems is shrub expansion above the tree line. However, previous studies have found that reindeer can influence plant community responses to warming and inhibit shrubification of the tundra.We revisited grazed (ambient) and ungrazed study plots (exclosures), at the southern as well as the northern limits of the Swedish alpine region, to study long-term grazing effects and vegetation changes in response to increasing temperatures between 1995 and 2011, in two vegetation types (shrub heath and mountain birch forest).In the field layer at the shrub heath sites, evergreen dwarf shrubs had increased in cover from 26% to 49% but were unaffected by grazing. Deciduous dwarf and tall shrubs also showed significant, though smaller, increases over time. At the birch forest sites, the increase was similar for evergreen dwarf shrubs (20-48%) but deciduous tall shrubs did not show the same consistent increase over time as in the shrub heath.The cover and height of the shrub layer were significantly greater in exclosures at the shrub heath sites, but no significant treatment effects were found on species richness or diversity.July soil temperatures and growing season thawing degree days (TDD) were higher in exclosures at all but one site, and there was a significant negative correlation between mean shrub layer height and soil TDD at the shrub heath sites. Synthesis . This study shows that shrub expansion is occurring rapidly in the Scandes mountain range, both above and below the tree line. Tall, deciduous shrubs had benefitted significantly from grazing exclosure, both in terms of cover and height, which in turn lowered summer soil temperatures. However, the overriding vegetation shift across our sites was the striking increase in evergreen dwarf shrubs, which were not influenced by grazing. As the effects of an increase in evergreen dwarf shrubs and more recalcitrant plant litter may to some degree counteract some of the effects of an increase in deciduous tall shrubs, herbivore influence on shrub interactions is potentially of great importance for shaping arctic shrub expansion and its associated ecosystem effects.

Controls on vegetation structure in Southwestern ponderosa pine forests, 1941 and 2004.

PubMed

Bakker, Jonathan D; Moore, Margaret M

2007-09-01

Long-term studies can broaden our ecological understanding and are particularly important when examining contingent effects that involve changes to dominance by long-lived species. Such a change occurred during the last century in Southwestern (USA) ponderosa pine (Pinus ponderosa) forests. We used five livestock grazing exclosures established in 1912 to quantify vegetation structure in 1941 and 2004. Our objectives were to (1) assess the effects of historical livestock grazing on overstory structure and age distribution, (2) assess the effects of recent livestock grazing and overstory on understory vegetation, and (3) quantify and explain changes in understory vegetation between 1941 and 2004. In 1941, canopy cover of tree regeneration was significantly higher inside exclosures. In 2004, total tree canopy cover was twice as high, density was three times higher, trees were smaller, and total basal area was 40% higher inside exclosures. Understory species density, herbaceous plant density, and herbaceous cover were negatively correlated with overstory vegetation in both years. Most understory variables did not differ between grazing treatments in 1941 but were lower inside exclosures in 2004. Differences between grazing treatments disappeared once overstory effects were accounted for, indicating that they were due to the differential overstory response to historical livestock grazing practices. Between 1941 and 2004, species density declined by 34%, herbaceous plant density by 37%, shrub cover by 69%, total herbaceous cover by 59%, graminoid cover by 39%, and forb cover by 82%. However, these variables did not differ between grazing treatments or years once overstory effects were accounted for, indicating that the declines were driven by the increased dominance of the overstory during this period. Our results demonstrate that historical livestock grazing practices are an aspect of land-use history that can affect ecosystem development. Grazing history must be considered when extrapolating results from one site to another. In addition, the understory vegetation was more strongly controlled by the ponderosa pine overstory than by recent livestock grazing or by temporal dynamics, indicating that overstory effects must be accounted for when examining understory responses in this ecosystem.

Foot loading characteristics during three fencing-specific movements.

PubMed

Trautmann, Caroline; Martinelli, Nicolo; Rosenbaum, Dieter

2011-12-01

Plantar pressure characteristics during fencing movements may provide more specific information about the influence of foot loading on overload injury patterns. Twenty-nine experienced fencers participated in the study. Three fencing-specific movements (lunge, advance, retreat) and normal running were performed with three different shoe models: Ballestra (Nike, USA), Adistar Fencing Lo (Adidas, Germany), and the fencers' own shoes. The Pedar system (Novel, Munich, Germany) was used to collect plantar pressures at 50 Hz. Peak pressures, force-time integrals and contact times for five foot regions were compared between four athletic tasks in the lunge leg and supporting leg. Plantar pressure analysis revealed characteristic pressure distribution patterns for the fencing movements. For the lunge leg, during the lunge and advance movements the heel is predominantly loaded; during retreat, it is the hallux. For the supporting leg, during the lunge and advance movements the forefoot is predominantly loaded; during retreat, it is the hallux. Fencing-specific movements load the plantar surface in a distinct way compared with running. An effective cushioning in the heel and hallux region would help to minimize foot loading during fencing-specific movements.

An exploratory study of apex fence flaps on a 74 deg delta wing

NASA Technical Reports Server (NTRS)

Wahls, R. A.; Vess, R. J.

1985-01-01

An exploratory wind tunnel investigation was performed to observe the flow field effects produced by vertically deployed apex fences on a planar 74 degree delta wing. The delta shaped fences, each comprising approximately 3.375 percent of the wing area, were affixed along the first 25 percent of the wing leading edge in symmetric as well as asymmetric (i.e., fence on one side only) arrangements. The vortex flow field was visualized at angles of attack from 0 to 20 degrees using helium bubble and oil flow techniques; upper surface pressures were also measured along spanwise rows. The results were used to construct a preliminary description of the vortex patterns and induced pressures associated with vertical apex fence deployment. The objective was to obtain an initial evaluation of the potential of apex fences as vortex devices for subsonic lift modulation as well as lateral directional control of delta wing aircraft.

Numerical evaluation of the scale problem on the wind flow of a windbreak

PubMed Central

Liu, Benli; Qu, Jianjun; Zhang, Weimin; Tan, Lihai; Gao, Yanhong

2014-01-01

The airflow field around wind fences with different porosities, which are important in determining the efficiency of fences as a windbreak, is typically studied via scaled wind tunnel experiments and numerical simulations. However, the scale problem in wind tunnels or numerical models is rarely researched. In this study, we perform a numerical comparison between a scaled wind-fence experimental model and an actual-sized fence via computational fluid dynamics simulations. The results show that although the general field pattern can be captured in a reduced-scale wind tunnel or numerical model, several flow characteristics near obstacles are not proportional to the size of the model and thus cannot be extrapolated directly. For example, the small vortex behind a low-porosity fence with a scale of 1:50 is approximately 4 times larger than that behind a full-scale fence. PMID:25311174

Fencing data transfers in a parallel active messaging interface of a parallel computer

DOEpatents

Blocksome, Michael A.; Mamidala, Amith R.

2015-06-02

Fencing data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task; the compute nodes coupled for data communications through the PAMI and through data communications resources including at least one segment of shared random access memory; including initiating execution through the PAMI of an ordered sequence of active SEND instructions for SEND data transfers between two endpoints, effecting deterministic SEND data transfers through a segment of shared memory; and executing through the PAMI, with no FENCE accounting for SEND data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all SEND instructions initiated prior to execution of the FENCE instruction for SEND data transfers between the two endpoints.

Fencing direct memory access data transfers in a parallel active messaging interface of a parallel computer

DOEpatents

Blocksome, Michael A.; Mamidala, Amith R.

2013-09-03

Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to segments of shared random access memory through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and a segment of shared memory; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

Fencing data transfers in a parallel active messaging interface of a parallel computer

DOEpatents

Blocksome, Michael A.; Mamidala, Amith R.

2015-06-09

Fencing data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task; the compute nodes coupled for data communications through the PAMI and through data communications resources including at least one segment of shared random access memory; including initiating execution through the PAMI of an ordered sequence of active SEND instructions for SEND data transfers between two endpoints, effecting deterministic SEND data transfers through a segment of shared memory; and executing through the PAMI, with no FENCE accounting for SEND data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all SEND instructions initiated prior to execution of the FENCE instruction for SEND data transfers between the two endpoints.

Fencing data transfers in a parallel active messaging interface of a parallel computer

DOEpatents

Blocksome, Michael A.; Mamidala, Amith R.

2015-08-11

Fencing data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint comprising a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes coupled for data communications through the PAMI and through data communications resources including a deterministic data communications network, including initiating execution through the PAMI of an ordered sequence of active SEND instructions for SEND data transfers between two endpoints, effecting deterministic SEND data transfers; and executing through the PAMI, with no FENCE accounting for SEND data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all SEND instructions initiated prior to execution of the FENCE instruction for SEND data transfers between the two endpoints.

Fencing direct memory access data transfers in a parallel active messaging interface of a parallel computer

DOEpatents

Blocksome, Michael A; Mamidala, Amith R

2014-02-11

Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to segments of shared random access memory through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and a segment of shared memory; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

Fencing data transfers in a parallel active messaging interface of a parallel computer

DOEpatents

Blocksome, Michael A.; Mamidala, Amith R.

2015-06-30

Fencing data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint comprising a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes coupled for data communications through the PAMI and through data communications resources including a deterministic data communications network, including initiating execution through the PAMI of an ordered sequence of active SEND instructions for SEND data transfers between two endpoints, effecting deterministic SEND data transfers; and executing through the PAMI, with no FENCE accounting for SEND data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all SEND instructions initiated prior to execution of the FENCE instruction for SEND data transfers between the two endpoints.

Fencing network direct memory access data transfers in a parallel active messaging interface of a parallel computer

DOEpatents

Blocksome, Michael A.; Mamidala, Amith R.

2015-07-07

Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to a deterministic data communications network through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and the deterministic data communications network; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

Fencing network direct memory access data transfers in a parallel active messaging interface of a parallel computer

DOEpatents

Blocksome, Michael A.; Mamidala, Amith R.

2015-07-14

Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to a deterministic data communications network through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and the deterministic data communications network; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

Plant Diversity in Live Fences and Pastures, Two Examples from the Mexican Humid Tropics

NASA Astrophysics Data System (ADS)

Ruiz-Guerra, Betsabé; Rosas, Noé Velázquez; López-Acosta, Juan Carlos

2014-09-01

This study analyzes the potential uses of live fences and pastures as reservoirs of plant diversity for two regions with different management histories, Los Tuxtlas (LT) and Uxpanapa (UX), Veracruz, México. We studied two habitats, live fences and pastures, analyzed their species richness, diversity, structure and plant composition and classified species according to plant regeneration modes (light-demanding and shade tolerant), seed dispersal syndrome and their local uses. We recorded 62 species of trees at LT and 48 at UX. Live fences were more diverse than pastures in both regions. The LT site showed to analyze the relationship a higher diversity of plants in regeneration stages than the one at UX. However, UX had higher diversity of adult plants in the pastures than LT. Composition and structure of live fences were different between regions, as well as within live fences and pastures, 53 % of species were light-demanding and 40 % were shade tolerant; 70 % of the species were dispersed by birds. Differences between sites are associated with the modifications in live fences structure, which changed according to managerial practices and the use of local species; this may influence plant regeneration modes as well as the visits of avian dispersal agents. In LT, all species found in live fences were useful to humans, whereas in UX, less than half were used by the local population. Our results underline the importance of live fences and isolated trees in pasture habitats as potential sites to host native and useful species from tropical rain forests in livestock landscapes.

Beehive fences as a multidimensional conflict-mitigation tool for farmers coexisting with elephants.

PubMed

King, Lucy E; Lala, Fredrick; Nzumu, Hesron; Mwambingu, Emmanuel; Douglas-Hamilton, Iain

2017-08-01

Increasing habitat fragmentation and human population growth in Africa has resulted in an escalation in human-elephant conflict between small-scale farmers and free-ranging African elephants (Loxodonta Africana). In 2012 Kenya Wildlife Service (KWS) implemented the national 10-year Conservation and Management Strategy for the Elephant in Kenya, which includes an action aimed at testing whether beehive fences can be used to mitigate human-elephant conflict. From 2012 to 2015, we field-tested the efficacy of beehive fences to protect 10 0.4-ha farms next to Tsavo East National Park from elephants. We hung a series of beehives every 10 m around the boundary of each farm plot. The hives were linked with strong wire. After an initial pilot test with 2 farms, the remaining 8 of 10 beehive fences also contained 2-dimensional dummy hives between real beehives to help reduce the cost of the fence. Each trial plot had a neighboring control plot of the same size within the same farm. Of the 131 beehives deployed 88% were occupied at least once during the 3.5-year trial. Two hundred and fifty-three elephants, predominantly 20-45 years old entered the community farming area, typically during the crop- ripening season. Eighty percent of the elephants that approached the trial farms were kept out of the areas protected by the beehive fences, and elephants that broke a fence were in smaller than average groups. Beehive fences not only kept large groups of elephants from invading the farmland plots but the farmers also benefited socially and financially from the sale of 228 kg of elephant-friendly honey. As news of the success of the trial spread, a further 12 farmers requested to join the project, bringing the number of beehive fence protected farms to 22 and beehives to 297. This demonstrates positive adoption of beehive fences as a community mitigation tool. Understanding the response of elephants to the beehive fences, the seasonality of crop raiding and fence breaking, and the willingness of the community to engage with the mitigation method will help contribute to future management strategies for this high human-elephant conflict hotspot and other similar areas in Kenya. © 2017 Society for Conservation Biology.

Tip Fence for Reduction of Lift-Generated Airframe Noise

NASA Technical Reports Server (NTRS)

Ross, James C. (Inventor); Storms, Bruce L. (Inventor)

1998-01-01

The present invention is directed toward a unique lift-generated noise reduction apparatus. This apparatus includes a plurality of tip fences that are secured to the trailing and leading assemblies of the high-lift system, as close as possible to the discontinuities where the vortices are most likely to form. In one embodiment, these tip fences are secured to some or all of the outboard and inboard tips of the wing slats and flaps. The tip fence includes a generally flat, or an aerodynamically shaped plate or device that could be formed of almost any rigid material, such as metal, wood, plastic, fiber glass, aluminum, etc. In a preferred embodiment, the tip fences extend below and perpendicularly to flaps and the slats to which they are attached, such that these tip fences are aligned with the nominal free stream velocity of the aircraft. In addition to reducing airframe noise, the tip fence tends to decrease drag and to increase lift, thus improving the overall aerodynamic performance of the aircraft. Another advantage presented by the tip fence lies in the simplicity of its design, its elegance, and its ready ability to fit on the wing components, such as the flaps and the slats. Furthermore, it does not require non-standard materials or fabrication techniques, and it can be readily, easily and inexpensively retrofited on most of the existing aircraft, with minimal design changes.

Fence Posts From Delta Hardwoods Give Good Service

Treesearch

J. S. McKnight; J. W. Johnson

1953-01-01

Do bottomland hardwoods make durable fence posts? To answer this question, the Southern Forest Experiment Station and the Mississippi Agricultural Experiment Station have been carrying on two tests of the life of fence pasts in actual service in the Delta.

Stream Phosphorus Dynamics Along a Suburbanizing Gradient in Southern Ontario, Canada

NASA Astrophysics Data System (ADS)

Duval, T. P.

2017-12-01

While it is well known that urban streams are subject to impaired water quality relative to natural analogues, far less research has been directed at stream water quality during the process of (sub-) urbanization. This study determines the role of housing construction activities in Brampton, Canada on the concentration and flux of phosphorus (P) of a headwater stream. Prior to development the stream was engineered with a riffle-pool sequence, riparian plantings, and a floodplain corridor that was lined with sediment fencing. Stream sites were sampled daily over a period of six months at locations representing varying stages of subdivision completion (upper site -active construction; middle site -finished construction and natural vegetation; lower site -finished construction and active construction). A nearby urban stream site developed ten years prior to this study was selected as a reference site. There were no differences in total phosphorus (TP) levels or flux between the suburbanizing and urban streams; however, the forms of P differed between sites. The urban stream TP load was dominated by particulate phosphorus (PP) while suburbanizing stream P was mainly in the dissolved organic phosphorus (DOP) form. The importance of DOP to TP flux increased with the onset of the growing season. TP levels in all stream segments frequently exceeded provincial water quality guidelines during storm events but were generally low during baseflow conditions. During storm events PP and total suspended solid levels in the suburbanizing stream reached levels of the urban stream due to sediment fence failure at several locations along the construction-hillslope interface. Along the suburbanizing gradient, the hydrological connection to a mid-reach zone of no-construction activity / fallow field and native forest resulted in significantly lower P levels than the upper suburbanizing stream site. This suggests that stream channel design features as well as timing of construction activities and the hydrological connection between the stream and construction projects all contribute to downstream export of nutrients and ultimately stream water quality.

Connectivity of the Asiatic wild ass population in the Mongolian Gobi

PubMed Central

Kaczensky, Petra; Kuehn, Ralph; Lhagvasuren, Badamjav; Pietsch, Stephanie; Yang, Weikang; Walzer, Chris

2011-01-01

Long-distance migrations of wildlife have been identified as important biological phenomena, but their conservation remains a major challenge. The Mongolian Gobi is one of the last refuges for the Asiatic wild ass (Equus hemionus) and other threatened migratory mammals. Using historic and current distribution ranges, population genetics, and telemetry data we assessed the connectivity of the wild ass population in the context of natural and anthropogenic landscape features and the existing network of protected areas. In the Mongolian Gobi mean biomass production is highly correlated with human and livestock density and seems to predict wild ass occurrence at the upper level. The current wild ass distribution range largely falls into areas below the 250 gC/m2/year productivity isoline, suggesting that under the present land use more productive areas have become unavailable for wild asses. Population genetics results identified two subpopulations and delineated a genetic boundary between the Dzungarian and Transaltai Gobi for which the most likely explanation are the mountain ranges separating the two areas. Home ranges and locations of 19 radiomarked wild asses support the assumed restricting effects of more productive habitats and mountain ranges and additionally point towards a barrier effect of fences. Furthermore, telemetry data shows that in the Dzungarian and Transaltai Gobi individual wild ass rarely ventured outside of the protected areas, whereas in the southeast Gobi asses only spend a small fraction of their time within the protected area network. Conserving the continuity of the wild ass population will need a landscape level approach, also including multi-use landscapes outside of protected areas, particularly in the southeast Gobi. In the southwest Gobi, allowing for openings in the border fence to China and managing the border area as an ecological corridor would connect three large protected areas together covering over 70,000 km2 of wild ass habitat. PMID:21461051

Connectivity of the Asiatic wild ass population in the Mongolian Gobi.

PubMed

Kaczensky, Petra; Kuehn, Ralph; Lhagvasuren, Badamjav; Pietsch, Stephanie; Yang, Weikang; Walzer, Chris

2011-02-01

Long-distance migrations of wildlife have been identified as important biological phenomena, but their conservation remains a major challenge. The Mongolian Gobi is one of the last refuges for the Asiatic wild ass (Equus hemionus) and other threatened migratory mammals. Using historic and current distribution ranges, population genetics, and telemetry data we assessed the connectivity of the wild ass population in the context of natural and anthropogenic landscape features and the existing network of protected areas. In the Mongolian Gobi mean biomass production is highly correlated with human and livestock density and seems to predict wild ass occurrence at the upper level. The current wild ass distribution range largely falls into areas below the 250 gC/m(2)/year productivity isoline, suggesting that under the present land use more productive areas have become unavailable for wild asses. Population genetics results identified two subpopulations and delineated a genetic boundary between the Dzungarian and Transaltai Gobi for which the most likely explanation are the mountain ranges separating the two areas. Home ranges and locations of 19 radiomarked wild asses support the assumed restricting effects of more productive habitats and mountain ranges and additionally point towards a barrier effect of fences. Furthermore, telemetry data shows that in the Dzungarian and Transaltai Gobi individual wild ass rarely ventured outside of the protected areas, whereas in the southeast Gobi asses only spend a small fraction of their time within the protected area network. Conserving the continuity of the wild ass population will need a landscape level approach, also including multi-use landscapes outside of protected areas, particularly in the southeast Gobi. In the southwest Gobi, allowing for openings in the border fence to China and managing the border area as an ecological corridor would connect three large protected areas together covering over 70,000 km(2) of wild ass habitat.

Tibial shock measured during the fencing lunge: the influence of footwear.

PubMed

Sinclair, Jonathan; Bottoms, Lindsay; Taylor, Katrina; Greenhalgh, Andrew

2010-06-01

Fencing is a high-intensity sport involving dynamic movements such as the lunge exposing the musculoskeletal system to high impact forces, which emphasises the importance of the shock attenuating properties of footwear as a factor in the prevention of injury. The aim of this study was to investigate the magnitudes of the transient axial impact shock experienced at the tibia between traditional fencing shoes and standard athletic footwear during the impact phase of the fencing lunge. Peak tibial shock was measured in 19 male fencers in 4 different footwear conditions using an accelerometer placed on the distal aspect of the tibia. The standard footwear (11.08 g and 8.75 g for squash and running shoe, respectively) resulted in significant (p < 0.01) reductions in peak impact shock in comparison to the traditional fencing shoes (15.93 g and 13.97 g for the Adidas and Hi-Tec shoe, respectively). No significant differences were found between the running and squash shoes (p = 0.09) or between the fencing shoes (p = 0.48). The documented reduction in impact shock found suggests that running or squash specific footwear may reduce overuse injury occurrence, indicating that there is justification for a re-design of fencing shoes.

Gary O's Fence Question.

ERIC Educational Resources Information Center

Daniels, David S.

1993-01-01

Discusses the problem of finding the amount of fence it would require for the outfield fence of a baseball field of given dimensions. Presents different solution methods for each of the levels from grades 9-12. The different methods incorporate geometry, trigonometry, analytic geometry, and calculus. (MDH)

[Application of electronic fence technology based on GIS in Oncomelania hupensis snail monitoring].

PubMed

Zhi-Hua, Chen; Yi-Sheng, Zhu; Zhi-Qiang, Xue; Xue-Bing, Li; Yi-Min, Ding; Li-Jun, Bi; Kai-Min, Gao; You, Zhang

2017-07-27

To study the application of Geographic Information System (GIS) electronic fence technique in Oncomelania hupensis snail monitoring. The electronic fence was set around the history and existing snail environments in the electronic map, the information about snail monitoring and controlling was linked to the electronic fence, and the snail monitoring information system was established on these bases. The monitoring information was input through the computer and smart phone. The electronic fence around the history and existing snail environments was set in the electronic map (Baidu map), and the snail monitoring information system and smart phone APP were established. The monitoring information was input and upload real-time, and the snail monitoring information was demonstrated in real time on Baidu map. By using the electronic fence technology based on GIS, the unique "environment electronic archives" for each snail monitoring environment can be established in the electronic map, and real-time, dynamic monitoring and visual management can be realized.

Fencing direct memory access data transfers in a parallel active messaging interface of a parallel computer

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

Blocksome, Michael A.; Mamidala, Amith R.

2013-09-03

Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to segments of shared random access memory through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and a segmentmore » of shared memory; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.« less

Friendship Fence

ERIC Educational Resources Information Center

Johnson, Ann

2007-01-01

A friendship fence is a wonderful alternative to the standard mural. It provides a fantastic opportunity for children to help design a creative learning environment. In this article, the author describes an art project that involves creating a friendship fence. The author relates that she began introducing her students to Ndebele beadwork dolls…

Techniques to construct New Zealand elk-proof fence.

Treesearch

Larry D. Bryant; Jack W. Thomas; Mary M. Rowland

1993-01-01

An elk-proof fence was built in 1987 at the Starkey Experimental Forest and Range in northeast Oregon. The 25,000-acre research enclosure holds several hundred Rocky Mountain elk (Cervus elaphus nelsoni V. Bailey) and Rocky Mountain mule deer (Odocoileus hemionus hemionus Rafinesque) year round. The fence, constructed with high...

On Fences, Forms and Mathematical Modeling

ERIC Educational Resources Information Center

Lege, Jerry

2009-01-01

The white picket fence is an integral component of the iconic American townscape. But, for mathematics students, it can be a mathematical challenge. Picket fences in a variety of styles serve as excellent sources to model constant, step, absolute value, and sinusoidal functions. "Principles and Standards for School Mathematics" (NCTM 2000)…

Assessment of Fencing on the Orion Heatshield

NASA Technical Reports Server (NTRS)

Alunni, Antonella I.; Gokcen, Tahir

2016-01-01

This paper presents recent experimental results from arc-jet tests of the Orion heatshield that were conducted at NASA Ames Research Center. Test conditions that simulated a set of heating profiles in time representative of the Orion flight environments were used to observe their effect on Orion's block architecture in terms of differential recession or fencing. Surface recession of arc-jet models was characterized during and after testing to derive fencing profiles used for the baseline sizing of the heatshield. Arc-jet test data show that the block architecture produces varying degrees of fencing.

Wind fence enclosures for infrasonic wind noise reduction.

PubMed

Abbott, JohnPaul; Raspet, Richard; Webster, Jeremy

2015-03-01

A large porous wind fence enclosure has been built and tested to optimize wind noise reduction at infrasonic frequencies between 0.01 and 10 Hz to develop a technology that is simple and cost effective and improves upon the limitations of spatial filter arrays for detecting nuclear explosions, wind turbine infrasound, and other sources of infrasound. Wind noise is reduced by minimizing the sum of the wind noise generated by the turbulence and velocity gradients inside the fence and by the area-averaging the decorrelated pressure fluctuations generated at the surface of the fence. The effects of varying the enclosure porosity, top condition, bottom gap, height, and diameter and adding a secondary windscreen were investigated. The wind fence enclosure achieved best reductions when the surface porosity was between 40% and 55% and was supplemented by a secondary windscreen. The most effective wind fence enclosure tested in this study achieved wind noise reductions of 20-27 dB over the 2-4 Hz frequency band, a minimum of 5 dB noise reduction for frequencies from 0.1 to 20 Hz, constant 3-6 dB noise reduction for frequencies with turbulence wavelengths larger than the fence, and sufficient wind noise reduction at high wind speeds (3-6 m/s) to detect microbaroms.

WLCI researchers employ new approaches to help managers conserve deer migrations

USGS Publications Warehouse

Allen, Leslie A.; Kauffman, Matthew J.

2012-01-01

Elk, mule deer, pronghorn antelope, moose, and bighorn sheep are iconic animals of the American West. These hooved animals, known as ungulates, commonly travel 30–60 miles between seasonal ranges. These migrations between winter and summer ranges are vital for survival and reproduction. As habitat fragmentation continues, the conservation of ungulate migration routes has received considerable attention in the West and across the globe. For example, it is estimated that many ungulate migration routes in the Greater Yellowstone Ecosystem have already been lost. The traditional migration routes of Wyoming ungulates are threatened by unprecedented levels of energy development and by increasing levels of rural ranchette development (including fences, structures, and roads). In the past, migration corridors have been mapped based primarily on the expert opinions of state game managers, but long-term conservation of Wyoming's ungulate migration routes requires a better understanding of migration ecology and more sophisticated management tools. Wyoming Landscape Conservation Initiative (WLCI) researchers investigated the migration of a large mule deer herd across the Dad and Wild Horse winter ranges in southwest Wyoming, where 2,000 gas wells and 1,609 kilometers of pipelines and roads have been proposed for development.

Lower Gila South Resource Management Plan, La Paz, Maricopa, Pima, Pinal and Yuma Counties, Arizona

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

Not Available

1985-08-01

Implementation of a resource management plan is proposed for 2.0 million surface acres and 1.9 million acres of subsurface minerals in the Lower Gila South resource area, located in La Paz, Maricopa, Pima, Pinal, and Yuma counties, Arizona. The preferred alternative would involve range land improvements consisting of construction of 47 miles of fence, 10 reservoirs and 7 wells. Portions of the New Water Mountains, Eagletail Mountains, Woosley Peak, and Table Top Mountains wilderness study areas (WSAs), totaling 190,391 acres, would be designated as wilderness. The remaining portions of these WSAs and eight other WSAs, totaling 431,540 acres, would notmore » be recommended for wilderness designation and would revert to multiple-use management. Approximately 72,123 acres of isolated land parcels would be made available for sale or exchange, approximately 36,845 acres of nonpublic lands would be acquired, 112,160 acres of state and private mineral estate would be acquired, and 23,645 acres of federal minerals would be disposed of to facilitate management. Ten utility corridors would be designated. Mineral access and off-road vehicle use would be restricted on the lands proposed for wilderness designation.« less

Landscape structure and live fences in Andes Colombian agrosystems: upper basin of the Cane-Iguaque River.

PubMed

Otero, Javier; Onaindia, Miren

2009-12-01

Changes in land use have generated a new landscape configuration in the Andino orobiome (mountain range) of the tropical Andes, resulting in a mosaic of cultivation and pastures interrupted by small fragments of forest and live fences. This has resulted in an ongoing decrease in the biodiversity of this biome. In the upper basin of the Cane-Iguaque River (Villa de Levya-Boyacá, Colombia), located 2,600-3,000 m above the Cordillera Oriental, over three time periods in 1960, 1984, and 2004, we characterized the structure, patterns, and evolution of the overall landscape and of the live fences (used as tools in biodiversity conservation and considered to be desirable alternatives to nonlive fences in farming production systems) within an agricultural landscape. To do this, we interpreted high-resolution satellite images using a landscape ecology approach and applied landscape map metrics. We found that the natural forests have been transformed by pastures and cultivation, and that although live fences cover only a small portion of the total landscape (4.6%), they have an important effect on landscape structure and biodiversity. There has been an increase in live fences, especially between 1960 and 1984, as well as an increase in their density. However, there has been a reduction in the average length of live fences over the periods that we studied. This could be due in part to changes in the types of agricultural products that have been cultivated in recent years, with an increase in potatoes and a decrease in other vegetables, and also by resource extraction of timber and fuel wood. In the studied area, agricultural production was sustained while biodiversity conservation was improved by the use of live fences. Therefore, live fences should be considered not only as part of an agriculturally productive area, but also as an important element of a multi-functional landscape that contributes to the maintenance of biodiversity and provides resources of economic and ecological interest, decreasing the pressure on natural forest. Improving the network of live fences constitutes an important strategy for the sustainable management of the rural landscape of the Andino orobiome of Colombia and similar areas in the tropics.

Monitoring wildlife-vehicle collisions : analysis and cost-benefit of escape ramps for deer and elk on U.S. highway 550.

DOT National Transportation Integrated Search

2015-05-01

Wildlife fencing along highways can lower wildlife-vehicle collision rates by excluding animals from the road right-of-way. Still, animals can : breach fencing and end up trapped within the fencing along the highway right-of-way, exposing wildlife an...

76 FR 8709 - Environmental Impact Statement; Proposed Cattle Fever Tick Control Barrier in South Texas

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-15

... tick control barrier using game fencing to keep cattle fever ticks and southern cattle ticks out of... zone include horseback patrols, a segmented barrier consisting of game fencing, and treatments applied... determined that the installation of additional game fencing in the permanent quarantine zone would...

Lift Augmentation on a Delta Wing via Leading Edge Fences and the Gurney Flap

NASA Technical Reports Server (NTRS)

Buchholz, Mark D.; Tso, Jin

1993-01-01

Wind tunnel tests have been conducted on two devices for the purpose of lift augmentation on a 60 deg delta wing at low speed. Lift, drag, pitching moment, and surface pressures were measured. Detailed flow visualization was also obtained. Both the leading edge fence and the Gurney flap are shown to increase lift. The fences and flap shift the lift curve by as much as 5 deg and 10 deg, respectively. The fences aid in trapping vortices on the upper surface, thereby increasing suction. The Gurney flap improves circulation at the trailing edge. The individual influences of both devices are roughly additive, creating high lift gain. However, the lower lift to drag ratio and the precipitation of vortex burst caused by the fences, and the nose down pitching moment created by the flap are also significant factors.

John Day River Subbasin Fish Habitat Enhancement Project, 2002 Annual Report.

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

Powell, Russ M.; Jerome, James P.; Delano, Kenneth H.

2003-03-01

Work undertaken in 2002 included: (1) Seven new fence projects were completed thereby protecting 6.0 miles of stream (2) Completion of 0.7 miles of dredge tail leveling on Granite Creek. (3) New fence construction (300ft) plus one watergap on Indian Creek/ Kuhl property. (4) Maintenance of all active project fences (58.76 miles), watergaps (56), spring developments (32) and plantings were checked and repairs performed. (5) Restoration and Enhancement projects protected 3 miles of stream within the basin. (6) Since the initiation of the Fish Habitat Project in 1984 we have 67.21 miles of stream protected using 124.2 miles of fence.more » With the addition of the Restoration and Enhancement Projects we have 199.06 miles of fence protecting 124.57 miles of stream.« less

78 FR 44521 - Environmental Impact Statement; Proposed Cattle Fever Tick Control Barrier in South Texas

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-24

... result from installing game fencing as a barrier to keep animals that carry cattle fever ticks and..., we determined that game fencing could help prevent the spread of cattle fever ticks to U.S. cattle... toward installation of game fencing, with landowner consent and cost-share agreement, on privately owned...

77 FR 41973 - Record of Decision for the Entry Control Reconfiguration and Base Perimeter Fence Relocation in...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-17

... Reconfiguration and Base Perimeter Fence Relocation in area A Wright-Patterson AF Base, Ohio, Final Environmental..., 2012, the United States Air Force signed the ROD for the Entry Control Reconfiguration and Base Perimeter Fence Relocation in Area A Wright-Patterson Air Force Base (WPAFB), Ohio Final Environmental...

Fence Posts for Southern Farms

Treesearch

H. H. Muntz

1950-01-01

Of the more common woods native to the South, the heartwood of osageorange (bois d'arc), black locust, red mulberry, cedar, and baldcypress is most desirable and makes good fence posts without any preservative treatment. The heartwood of other southern tree species, and all sapwood is much less durable and will give only a few years of service when used for fence...

[Diurnal and Seasonal Dynamic Variation of Soil Respiration and Its Influencing Factors of Different Fenced Enclosure Years in Desert Steppec].

PubMed

Cui, Hai; Zhang, Ya-hong

2016-04-15

The fenced measures could improve the ecological environment of degraded grassland, it's a main measure for restoration of degraded grassland vegetation in China. Soil respiration (Rs) is an important component of an ecosystem's carbon cycle and the main pathway for carbon moving from the ecosystem to the atmosphere. In order to explore soil respiration characteristics and influencing factors of the different fenced years in arid desert grassland, we continuously observed Rs rate and environmental factors in the growing season of fenced enclosure 11a, 7a and no fenced (CK) desert steppe in Ningxia. The results showed that: (1) Both the diurnal andseasonal variations of Rs rate showed a single asymmetric peak changing in fenced enclosure of 11 years, 7 years, CK desert steppe. On the daily scale, the maximum and minimum values of Rs rate were found in the periods of 12:00-16:00 and 00:00-06:00,respectively. On the seasonal variation scale, the maximum value of Rs rate occurred in August with suitable precipitation and temperature conditions. And the Rs rate of the growing season of different fenced enclosure years was in the order of 11a [0.143 g · (m² · h)⁻¹] > 7a [0.138 g · (m² · h)⁻¹] > CK [0.106 g · (m2 - h)⁻¹]. (2) According to statistical analysis, it indicated that R² rate had a significant exponential positive relationship with air and soil temperature in fenced enclosure of 11 years, 7 years, CK desert steppe (P < 0.01). The order of the correlation of Rs rate and temperature was shown as soil surface temperature (R²: 0.408-0.413) > air temperature (R2: 0.355-0.376) > 5-20 cm soil temperature (R2: 0.263-0.394). The temperature sensitivity coefficient Q, increased gradually with the soil depth, and Q1, of different fenced enclosure years was showed as 11 a (2.728) > 7a (2.436) > CK (2.086). (3) A significant quadratic function model (P < 0.05) was observed for the relationship between Rs rate and relative air humidity, soil moisture content of fenced enclosure 11a, 7a and CK desert steppe in the whole growing season. Rs rate had a significant linear negative correlation with air carbon dioxide concentration (P < 0.01), a linear positive correlation with the windspeed (P < 0.05), and a significant weak linear positive correlation with light intensity (P < 0.01). (4) It showed that Rs increasedwith increasing fenced closure years in arid desert steppe, and temperature sensitivity coefficient Q₁₀ also increased with increasing fenced enclosure years. To sum up, 0-20 cm soil temperature and moisture were the main influencing factors of soil respiration of desert steppe. This study has important implications to understand the role that different fenced enclosure years play in carbon emission. Such information will lay a foundation for assessing carbon source or carbon sequestration of different fenced enclosure years in desert steppe. Therefore, our research results have important function for better managing grassland in desert steppe in Ningxia and other arid and semiarid areas of North China.

Effects of Streambank Fencing of Near-Stream Pasture Land on a Small Watershed in Lancaster County, Pennsylvania

USGS Publications Warehouse

Galeone, Daniel G.; Low, Dennis J.; Brightbill, Robin A.

2006-01-01

This study indicated that a small buffer width along a stream in pasture land can have a positive influence on surface-water quality, benthic macroinvertebrates, and near-stream shallow ground-water quality. Overland runoff processes that move suspended sediment to the stream were controlled (or reduced) to some extent by the vegetative buffer established. Results indicated streambank fencing resulted in decreases in N-species, total-P, and suspended-sediment concentrations and yields at the outlet of the treatment basin relative to untreated sites; however, dissolved-P concentrations and yields increased. These results indicate that nutrient management, in conjunction with streambank fencing, is important in helping to control nutrient loadings to streams in this agricultural setting. An upstream site (T-2) in the treatment basin showed post-treatment reductions in suspended-sediment yields and increases in N and P yields. The different results for these treated sites indicates the effects of streambank fencing should be studied at as large a scale as possible because field-scale influences on water quality as drainage area decreases can mute the effects of fencing. Benthic-macroinvertebrate data indicated streambank fencing had a positive influence on benthic macroinvertebrates and their habitat. More improvement was detected at the outlet of the treatment basin than the upstream sites. Probably the most important biological metric, taxa richness, indicated a greater number of benthic-macroinvertebrate taxa at treated relative to control sites after fencing. Results indicated fencing improved shallow ground-water quality (for the well nest in a stream-gaining area), as noted by decreased concentrations of N species and fecal-streptococcus counts. This improvement only occurred at the well nest where the stream was gaining water from the shallow ground-water system.

An investigation of rooftop STOL port aerodynamics

NASA Technical Reports Server (NTRS)

Blanton, J. N.; Parker, H. M.

1972-01-01

An investigation into aerodynamic problems associated with large building rooftop STOLports was performed. Initially, a qualitative flow visualization study indicated two essential problems: (1) the establishment of smooth, steady, attached flow over the rooftop, and (2) the generation of acceptable crosswind profile once (1) has been achieved. This study indicated that (1) could be achieved by attaching circular-arc rounded edge extensions to the upper edges of the building and that crosswind profiles could be modified by the addition of porous vertical fences to the lateral edges of the rooftop. Important fence parameters associated with crosswind alteration were found to be solidity, fence element number and spacing. Large scale building induced velocity fluctuations were discovered for most configurations tested and a possible explanation for their occurrence was postulated. Finally, a simple equation relating fence solidity to the resulting velocity profile was developed and tested for non-uniform single element fences with 30 percent maximum solidity.

Lift augmentation on a delta wing via leading edge fences and the Gurney flap. M.S. Thesis

NASA Technical Reports Server (NTRS)

Buchholz, Mark D.

1992-01-01

Wind tunnel tests were conducted on two devices for the purpose of lift augmentation on a 60 deg delta wing at low speed. Lift, drag, pitching moment, and surface pressures were measured. Detailed flow visualization was also obtained. Both the leading edge fence and the Gurney flap are shown to increase lift. The fences and flap shift the lift curve as much as 5 deg and 10 deg, respectively. The fences aid in trapping vortices on the upper surface, thereby increasing suction. The Gurney flap improves circulation at the trailing edge. The individual influences of both devices are roughly additive, creating high lift gain. However, the lower lift to drag ratio and the precipitation of vortex burst caused by the fences, and the nose down pitching moment created by the flap are also significant factors.

Teaching Electric Fences: The Physics Behind the Brainiac Video

NASA Astrophysics Data System (ADS)

Vollmer, Michael

2016-11-01

In many states, electric fences are used to prevent animals from leaving a designated area, for example for grazing. They are quite well known by most students and can therefore serve as daily-life examples of electric circuits. Besides helping to grasp the ideas of Kirchhoff's laws for voltages and currents in circuits according to loop and junction rules, they can also serve as introduction to the topic of conduction of electricity by humans and respective effects (in contrast to electric fences, the latter can also be studied experimentally in the classroom). Here we provide background information on the circuit diagrams of electrical fences that also explains the so-called Brainiac YouTube videos on the topic. While electric fences are designed not to be dangerous to humans or animals due to the short duration of the electrical pulses, students and teachers are strongly discouraged from attempting to replicate the scenes enacted in the video.

Higher Stakes--The Hidden Risks of School Security Fences for Children's Learning Environments

ERIC Educational Resources Information Center

Rooney, Tonya

2015-01-01

In a move away from the open or low-fenced grounds that have traditionally been a feature of Australian school design, the last decade has seen a growth in the installation of high-security fences around schools. These structures, far from being passive and neutral, act to redefine the possibilities for movement and connectivity in the local…

14 CFR 151.95 - Fences; distance markers; navigational and landing aids; and offsite work.

Code of Federal Regulations, 2014 CFR

2014-01-01

... or perimeter fences for security purposes are eligible for inclusion in a project. (b) A blast fence is eligible for inclusion in a project whenever— (1) It is necessary for safety at a runway end or a... distance markers for inclusion in a project is decided on a case-by-case basis. (d) The relocation of...

14 CFR 151.95 - Fences; distance markers; navigational and landing aids; and offsite work.

Code of Federal Regulations, 2012 CFR

2012-01-01

... or perimeter fences for security purposes are eligible for inclusion in a project. (b) A blast fence is eligible for inclusion in a project whenever— (1) It is necessary for safety at a runway end or a... distance markers for inclusion in a project is decided on a case-by-case basis. (d) The relocation of...

14 CFR 151.95 - Fences; distance markers; navigational and landing aids; and offsite work.

Code of Federal Regulations, 2013 CFR

2013-01-01

... or perimeter fences for security purposes are eligible for inclusion in a project. (b) A blast fence is eligible for inclusion in a project whenever— (1) It is necessary for safety at a runway end or a... distance markers for inclusion in a project is decided on a case-by-case basis. (d) The relocation of...

Approaches for Evaluating the Impact of Urban Encroachment on Installation Training/Testing

DTIC Science & Technology

2004-03-01

use outside the fence line ................................................................. 2 2 Causal links resulting in decreasing installation...GA. (The city of Columbus, GA, is NW of the installation.) .............................................. 35 10 A line -of-sight analysis; colored...boundaries were demarcated with fences and signs. Mili- tary training and testing could then take place “within the fence line .” However, some impacts of

14 CFR 151.95 - Fences; distance markers; navigational and landing aids; and offsite work.

Code of Federal Regulations, 2010 CFR

2010-01-01

... or perimeter fences for security purposes are eligible for inclusion in a project. (b) A blast fence is eligible for inclusion in a project whenever— (1) It is necessary for safety at a runway end or a... distance markers for inclusion in a project is decided on a case-by-case basis. (d) The relocation of...

Border Security Fencing and Wildlife: The End of the Transboundary Paradigm in Eurasia?

PubMed

Linnell, John D C; Trouwborst, Arie; Boitani, Luigi; Kaczensky, Petra; Huber, Djuro; Reljic, Slaven; Kusak, Josip; Majic, Aleksandra; Skrbinsek, Tomaz; Potocnik, Hubert; Hayward, Matt W; Milner-Gulland, E J; Buuveibaatar, Bayarbaatar; Olson, Kirk A; Badamjav, Lkhagvasuren; Bischof, Richard; Zuther, Steffen; Breitenmoser, Urs

2016-06-01

The ongoing refugee crisis in Europe has seen many countries rush to construct border security fencing to divert or control the flow of people. This follows a trend of border fence construction across Eurasia during the post-9/11 era. This development has gone largely unnoticed by conservation biologists during an era in which, ironically, transboundary cooperation has emerged as a conservation paradigm. These fences represent a major threat to wildlife because they can cause mortality, obstruct access to seasonally important resources, and reduce effective population size. We summarise the extent of the issue and propose concrete mitigation measures.

Border Security Fencing and Wildlife: The End of the Transboundary Paradigm in Eurasia?

PubMed Central

Linnell, John D. C.; Trouwborst, Arie; Boitani, Luigi; Kaczensky, Petra; Kusak, Josip; Skrbinsek, Tomaz; Buuveibaatar, Bayarbaatar; Bischof, Richard; Breitenmoser, Urs

2016-01-01

The ongoing refugee crisis in Europe has seen many countries rush to construct border security fencing to divert or control the flow of people. This follows a trend of border fence construction across Eurasia during the post-9/11 era. This development has gone largely unnoticed by conservation biologists during an era in which, ironically, transboundary cooperation has emerged as a conservation paradigm. These fences represent a major threat to wildlife because they can cause mortality, obstruct access to seasonally important resources, and reduce effective population size. We summarise the extent of the issue and propose concrete mitigation measures. PMID:27331878

Improvement in Capsule Abort Performance Using Supersonic Aerodynamic Interaction by Fences

NASA Astrophysics Data System (ADS)

Koyama, Hiroto; Wang, Yunpeng; Ozawa, Hiroshi; Doi, Katsunori; Nakamura, Yoshiaki

The space transportation system will need advanced abort systems to secure crew against serious accidents. Here this study deals with the capsule-type space transportation systems with a Launch Abort System (LAS). This system is composed of a conic capsule as a Launch Abort Vehicle (LAV) and a cylindrical rocket as a Service Module (SM), and the capsule is moved away from the rocket by supersonic aerodynamic interactions in an emergency. We propose a method to improve the performance of the LAV by installing fences at the edges of surfaces on the rocket and capsule sides. Their effects were investigated by experimental measurements and numerical simulations. Experimental results show that the fences on the rocket and capsule surfaces increase the aerodynamic thrust force on the capsule by 70% in a certain clearance between the capsule and rocket. Computational results show the detailed flow fields where the centripetal flow near the surface on the rocket side is induced by the fence on the rocket side and the centrifugal flow near the surface on the capsule side is blocked by the fence on the capsule side. These results can confirm favorable effects of the fences on the performance of the LAS.

The science of fencing: implications for performance and injury prevention.

PubMed

Roi, Giulio S; Bianchedi, Diana

2008-01-01

In this review we analyse the data from the literature on fencing with the aim of creating a psychobiological and multi-factorial model of fencing performance. Fencing is an open-skilled combat sport that was admitted to the first modern Olympic Games in Athens (1896). It is mainly practised indoors, with three different weapons: the foil, the sabre and the épée, each contested with different rules. A fencing international tournament may last between 9 and 11 hours. Bouts represent only 18% of total competition time, with an effective fight time of between 17 and 48 minutes. The physical demands of fencing competitions are high, involving the aerobic and anaerobic alactic and lactic metabolisms, and are also affected by age, sex, level of training and technical and tactical models utilized in relation to the adversary. The anthropometrical characteristics of fencers show a typical asymmetry of the limbs as a result of the practice of an asymmetrical sport activity. Fencing produces typical functional asymmetries that emphasize the very high level of specific function, strength and control required in this sport. Moreover, the physical demands of fencing are closely linked to the perceptual and psychological ones, and all are subjected to a continuous succession of changes during the bouts based on the behaviour of the opponent. For this reason it is difficult to identify a significant relationship between any one physiological characteristic and performance, and performance is more likely to be influenced by perceptual and neuro-physiological characteristics. Fencers need to anticipate the opponent and to mask their true intentions with a game of feints and counter-feints, which must be supported by an adequate psycho-physical condition to prevent central and peripheral fatigue. Fencing is not particularly dangerous; however, there is a fine line between a fatal lesion and a simple wound from a broken blade. The suggestions for injury prevention fall into three primary areas: (i) actions that can be taken by participants; (ii) improvements in equipment and facilities; and (iii) administration of fencing competitions. As in every other sport, the prevention of accidents must be accomplished at various levels and above all must involve the institutions that are responsible for safety in sports.

John Day River Subbasin Fish Habitat Enhancement Project, 2005-2006 Annual Report.

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

Powell, Russ M.; Alley, Pamela D.; Delano, Kenneth H.

2006-03-01

Work undertaken in 2005 included: (1) Four new fence projects were completed thereby protecting 7.55 miles of stream with 9.1 miles of new riparian fence (2) Fence removal 1.7 miles of barbed wire. (3) Completed three spring developments (repair work on two BLM springs on Cottonwood Creek (Dayville), 1 solar on Rock Creek/ Collins property). (4) Dredge tail leveling completed on 0.9 miles of the Middle Fork of the John Day River (5) Cut, hauled and placed 30 junipers on Indian Creek/Kuhl property for bank stability. (6) Collected and planted 1500 willow cuttings on Mountain Creek/Jones property. (7) Conducted steelheadmore » redd counts on Lake Cr./Hoover property and Cottonwood Cr./Mascall properties (8) Seeded 200 lbs of native grass seed on projects where the sites were disturbed by fence construction activities. (9) Maintenance of all active project fences (72.74 miles), watergaps (60), spring developments (30) were checked and repairs performed. (10) Since the initiation of the Fish Habitat Program in 1984 we have installed 156.06 miles of riparian fence on leased property protecting 88.34 miles of anadromous fish bearing stream. With the addition of the Restoration and Enhancement Projects from 1996-2001, where the landowner received the materials, built and maintained the project we have a total of 230.92 miles of fence protecting 144.7 miles of stream and 3285 acres of riparian habitat.« less

Impacts of mute swans (Cygnus olor) on submerged aquatic vegetation in Illinois River Valley backwaters

USGS Publications Warehouse

Stafford, Joshua D.; Michael W. Eichholz,; Adam C. Phillips,

2012-01-01

Wetland loss in North America has been considerable and well documented, and the establishment of exotic species in remaining wetlands can further reduce their ability to support native flora and fauna. In the Chesapeake Bay and Great Lakes ecosystems, exotic mute swans (Cygnus olor) have been found to negatively impact wetlands through degradation of submerged aquatic vegetation (SAV) communities. Mute swan populations have expanded into many areas of mid-continental North America outside the Great Lakes ecosystem, but the environmental impact of these populations is not well known. Mid-continental wetlands in North America differ in physical characteristics (e.g., size, depth, and permanency) and aquatic vegetation species composition compared to wetlands in other areas where mute swans have been studied and, thus, may be more or less susceptible to degradation from swan herbivory. To investigate the impact of mute swan herbivory on SAV communities in mid-continent wetlands, we used exclosures to prevent swans from foraging in 2 wetland complexes in central Illinois. Above-ground biomass of vegetation did not differ between exclosures and controls; however, mean below-ground biomass was greater in exclosures (52.0 g/m2, SE = 6.0) than in controls (34.4 g/m2 SE = 4.0). Thus, although swan densities were lower in our study region compared to that of previous studies, we observed potentially detrimental impacts of swan herbivory on below-ground biomass of SAV. Our results indicate that both above-ground and below-ground impacts of herbivory should be monitored, and below-ground biomass may be most sensitive to swan foraging.

Impacts of electronic deer exclusion fencing and soils on plant species abundance, richness, and diversity following clearcutting in Pennsylvania

Treesearch

Jonathan Lyon; William E. Sharpe

1995-01-01

Electric deer exclusion fencing has become a widely used management tool to promote hardwood regeneration in high deer browsing intensity areas. To assess the impacts of deer browsing on hardwood regeneration and vegetation patterns on clearcuts, six clearcuts with paired electric fenced and unfenced treatments were investigated. Additional data were collected on 10...

Umatilla River Basin Anadromus Fish Habitat Enhancement Project : 1994 Annual Report.

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

Shaw, R. Todd

1994-05-01

The Umatilla Basin Anadromous Fish Habitat Enhancement Project is funded under the Northwest Power Planning Council's Columbia River Basin Fish and Wildlife Program, Section 7.6-7.8 and targets the improvement of water quality and restoration of riparian areas, holding, spawning and rearing habitats of steelhead, spring and fall chinook and coho salmon. The project focused on implementing cooperative instream and riparian habitat improvements on private lands on the Umatilla Indian Reservation (hereafter referred to as Reservation) from April 1, 1988 to March 31, 1992. These efforts resulted in enhancement of the lower l/4 mile of Boston Canyon Creek, the lower 4more » river miles of Meacham Creek and 3.2 river miles of the Umatilla River in the vicinity of Gibbon, Oregon. In 1993, the project shifted emphasis to a comprehensive watershed approach, consistent with other basin efforts, and began to identify upland and riparian watershed-wide causative factors impacting fisheries habitat and natural fisheries production capabilities throughout the Umatilla River Watershed. During the 1994-95 project period, a one river mile demonstration project was implemented on two privately owned properties on Wildhorse Creek. This was the first watershed improvement project to be implemented by the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) off of the Reservation. Four 15 year riparian easements and two right-of-way agreements were secured for enhancement of one river mile on Wildhorse Creek and l/2 river mile on Meacham Creek. Enhancements implemented between river mile (RM) 9.5 and RM 10.5 Wildhorse Creek included: (1) installation of 1.43 miles of smooth wire high tensile fence line and placement of 0.43 miles of fence posts and structures to restrict livestock from the riparian corridor, (2) construction of eighteen sediment retention structures in the stream channel to speed riparian recovery by elevating the stream grade, slowing water velocities and depositing sediments onto streambanks to provide substrate for revegetation, and (3) revegetation of the stream corridor, terraces and adjacent pasture areas with 644 pounds of native grass seed (when commercially available) or close species equivalents and 4,000 native riparian shrub/tree species to assist in floodplain recovery, stream channel stability and filtering of sediments during high flow periods. Three hundred pounds of native grass/legume seed (including other grasses/legumes exhibiting native species characteristics) were broadcast in existing Boston Canyon Creek, Meacham Creek and Umatilla River project areas. The addition of two properties into the project area between RM 4.25 and RM 4.75 Meacham Creek during the 1995-96 work period will provide nearly complete project coverage of lower Meacham Creek corridor areas on the Reservation. Water quality monitoring continued for temperature and turbidity throughout the upper Umatilla River Watershed. Survey of cross sections and photo documentation of riparian recovery within the project areas provided additional baseline data. Physical habitat surveys continued to be conducted to characterize habitat quality and to quantify various habitat types by area. This information will be utilized to assist in identification of habitat deficient areas within the watershed in which to focus habitat restoration efforts. These efforts were coordinated with the CTUIR Umatilla Basin Natural Production Monitoring and Evaluation (UBNPME) Project. Poor land use practices, which have altered natural floodplain dynamics and significantly reduced or eliminated fisheries habitat, continued to be identified in the Mission Creek Subbasin. Complied data is currently being incorporated into a data layer for a Geographic Information System (GIS) data base. This effort is being coordinated with the Natural Resource Conservation Service (NRCS). Community outreach efforts and public education opportunities continued during the reporting period. CTUIR cooperatively sponsored a bioengineering workshop on February 23, 1995 with the Oregon Department of Fish and Wildlife (ODFW). This workshop attracted a combined total 3f over 270 participants at day and evening sessions.« less

SOIL MICROARTHROPODS AS INDICATORS OF EXPOSURE TO ENVIRONMENTAL STRESS IN CHIHUAHUAN DESERT RANGELANDS

EPA Science Inventory

We studied soil microarthropod communities along livestock grazing disturbance gradients, inside and outside grazing exclosures, and on areas subjected to restoration efforts (herbicide and bulldozing) in order to test the suitability of mites as indicators of rangeland soil qual...

SOIL MICROARTHROPODS AS INDICATORS OF EXPOSURE TO ENVIRONMENTAL STRESS IN CHIHUAHUAN DESERT RANGELANDS.

EPA Science Inventory

We studied soil microarthropod communities along livestock grazing disturbance gradients, inside and outside grazing exclosures, and on areas subjected to restoration efforts(herbicide and bulldozing)in order to test the suitability of mites as indicators of rangeland soil qualit...

Bats and birds increase crop yield in tropical agroforestry landscapes.

PubMed

Maas, Bea; Clough, Yann; Tscharntke, Teja

2013-12-01

Human welfare is significantly linked to ecosystem services such as the suppression of pest insects by birds and bats. However, effects of biocontrol services on tropical cash crop yield are still largely unknown. For the first time, we manipulated the access of birds and bats in an exclosure experiment (day, night and full exclosures compared to open controls in Indonesian cacao agroforestry) and quantified the arthropod communities, the fruit development and the final yield over a long time period (15 months). We found that bat and bird exclusion increased insect herbivore abundance, despite the concurrent release of mesopredators such as ants and spiders, and negatively affected fruit development, with final crop yield decreasing by 31% across local (shade cover) and landscape (distance to primary forest) gradients. Our results highlight the tremendous economic impact of common insectivorous birds and bats, which need to become an essential part of sustainable landscape management. © 2013 John Wiley & Sons Ltd/CNRS.

Fifteenmile Basin Habitat Enhancement Project: Annual Report FY 1988.

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

Smith, Roger C.; Marx, Steven D.

1989-04-01

The goal of the Fifteenmile Creek Habitat Enhancement Project is to improve wild winter steelhead in the Fifteenmile Creek Basin under the Columbia River Basin Fish and Wildlife Program. The project is funded by through the Bonneville Power Administration. Cooperators in the habitat enhancement project include the USDA Forest Service, Wasco County Soil and Water Conservation District and the Confederated Tribes of the Warms Springs. Installation of instream fish habitat structures was completed on four miles of Ramsey Creek and on one mile of Fifteenmile Creek. One hundred thirty-five structures were installed in treatment areas. Construction materials included logs andmore » rock. Riparian protection fencing was completed on Dry Creek and Ramsey Creek worksites. Five and one-half miles of new fence was added to existing fence on Ramsey Creek to afford riparian protection to four miles of stream. Six miles of stream on Dry Creek will be afforded riparian protection by constructing 4.5 miles of fence to complement existing fence. 2 refs., 5 figs.« less

Effectiveness of Wildlife Underpasses and Fencing to Reduce Wildlife–Vehicle Collisions

USGS Publications Warehouse

,; McCollister, Matthew F.

2010-01-01

Transportation planners are increasingly incorporating roadway design features to mitigate impacts of highways on wildlife and to increase driver safety. We used camera and track surveys to evaluate wildlife use before and after construction of 3 wildlife underpasses and associated fencing on a new section of United States Highway 64 in Washington County, North Carolina, USA. We recorded 242 occasions of white-tailed deer (Odocoileus virginianus) use of underpass areas before highway construction began. Following completion of the highway, we collected 2,433 photographs of 9 species with deer representing 93% of all crossings. Adjusting for differences in number of monitoring days, white-tailed deer use of underpass areas averaged 6.7 times greater after the new highway and underpasses were completed. We recorded 3,614 wildlife crossings of ≥20 species based on track counts, representing most medium and large mammals known to occur in the area and several reptiles and birds. After completion of the highway, we documented wildlife mortality due to vehicle collisions during a 13-month period and recorded 128 incidences representing ≥24 species. Within fenced highway segments, mortalities were lowest near underpasses and increased with distance from the underpasses. However, we also documented more mortalities in fenced areas compared with unfenced areas. With greater distance from an underpass, animals with smaller home ranges seemed less likely to reach the underpass and instead attempted to climb over or crawl under fencing. Based on collision reports from adjacent highway sections, the new section of United States Highway 64 experienced approximately 58% fewer wildlife mortalities (primarily white-tailed deer), suggesting underpasses and fencing reduced the number of deer–vehicle collisions. Continuous fencing between underpasses may further reduce the number of vehicle collisions for deer but additional design features (e.g., buried fencing) should be considered for other wildlife species.

A Study on the Wind Environment and Effects of Wind Fences around the Jang-Bogo Antarctica Station

NASA Astrophysics Data System (ADS)

Wang, J. W.; Kim, J.; Choi, W.; Kwon, H.

2017-12-01

This study investigated the influence of Jang-Bogo Antarctic Research Station on detailed flow and the effectiveness of wind fences on the surrounding observation environment using a computational fluid dynamics (CFD) model. The data obtained from the computer aided design (CAD) drawing were used to construct the terrain and buildings around Jang-Bogo Antarctic Research Station. To investigate the flow characteristics altered by Jang-Bogo Antarctic Research Station, we conducted the simulations for 16 different inflow directions and, for each inflow direction, we compared the flow characteristics before and after the construction of Jang-Bogo Antarctic Research Station. The observation data of automatic weather system (AWS) were used for comparison. The wind rose analysis shows that the wind speed and direction after the construction of the Jang-Bogo Antarctic Research Station are quite different from those before the construction. We also investigated effects of wind fences on the reduction of wind speeds around Jang-Bogo Antarctic Research Station, as one of the studies to reduce potential damages caused by katabatic wind. For this, we changed systematically the distance between the fences and the Jang-Bogo Antarctic Research Station (2H 8H with the increment of 2H, H is fence of height) and porosity of fences (0%, 25%, 33%, 50%, 67% and 75%). In the affiliated westerly cases, the AWS was located at the downwind side of the Jang-Bogo Antarctic Research Station and the effect of the construction were maximized (in the west-north-westerly case, the maximum decrease in wind speed was 81% compared to the wind speeds before the construction). In the case that the distance between the wind fence and the Jang-Bogo Antarctic Research Station was shortest, the wind speed reduction was maximized. With the same distance, the fence with medium porosities (25 33%) maximized the wind speed reduction.

Can lemmings control the expansion of woody plants on tundra?

NASA Astrophysics Data System (ADS)

Oksanen, Lauri; Oksanen, Tarja; Olofsson, Johan; Virtanen, Risto; Hoset, Katrine; Tuomi, Maria; Kyrö, Kukka

2013-04-01

The ongoing expansion of woody vegetation in the arctic, due to global warming, creates a positive feed back loop. Increasing abundance of woody plants reduces surface albedo both directly and via speeding up snow melt. Thus a successively greater fraction of incoming solar radiation is absorbed and converted to heat. Browsing mammals - both big and small - can prevent this by consuming woody plants. However, the grazer/browser community of many tundra areas is dominated by brown/Norwegian lemmings (Lemmus spp.) which eat graminoids and mosses and cannot use woody plants as forage. It would seem a priori likely that in such areas, mammalian herbivores speed up the expansion of woody plants by improving the chances of their seedlings to get established. We studied the impact of lemmings on woody plants by constructing lemming proof exclosures within piece high-altitude tundra at Joatkanjávri, northernmost Norway. The exclosures were constructed in 1998, during a period of low lemming densities, in snow-beds, where Norwegian lemmings (L. lemmus) were the only ecologically significant herbivorous mammals. (Reindeer migrate through the area in May, when snow-beds are inaccessible for them; during the fall migration, the area represents a dead end and is therefore avoided.) We chose pairs of maximally similar vegetation patches of 0.5 by 0.5 m and randomly assigned one of each pair to become an exclosure while the other plot was left open. The initial state of the vegetation was documented by the point frequency method. In 2008, after the 2007 lemming outbreak, the same documentation was repeated; thereafter the plots were harvested, the vegetation was sorted to species, oven dried and weighed. Exclusion of lemmings resulted to pronounced increase in community level plant biomass. Evergreen woody plants were especially favored by the exclusion of lemming: their above-ground biomass in exclosures was 14 times as great as their biomass on open reference plots. The results show that edibility plays a relatively small role for the vulnerability of woody plants to lemming impacts. As long as the plants are relatively small, like the evergreens were on our plots (the dominating species was the lingonberry, Vaccinium vitis-ideaea), they are mowed down by lemmings in outbreak years. The potential of lemmings to control the expansion of woody plants is thus likely to depend on the size of the seedlings of trees and shrubs and, therefore, on the frequency of lemming outbreaks

CFD Analysis of a T-38 Wing Fence

DTIC Science & Technology

2007-06-01

or making major adjustments to the existing airframe. The answer lies in flow control. Flow control devices like vortex generators, winglets , and wing...proposed by the Air Force Test Pilot School. The driving force for considering a wing fence as opposed to vane vortex generators or winglets 3 was a row of...devices are vortex generators, fences, high lift flaps, and winglets . Active flow control injects the boundary layer with energy from small jets of

Plant community dynamics in the shortgrass steppe 24 years after reversal of a grazing exclosure experiment

USDA-ARS?s Scientific Manuscript database

State and Transition Models are important decision-support tools for rangeland managers that suggest directional effects of both long-term grazing imposition and relaxation on plant community composition. However, most studies of the effects of grazing on semiarid rangelands evaluate only one direct...

Mapping landscape corridors

Treesearch

Peter Vogt; Kurt H. Riitters; Marcin Iwanowski; Christine Estreguil; Jacek Kozak; Pierre Soille

2007-01-01

Corridors are important geographic features for biological conservation and biodiversity assessment. The identification and mapping of corridors is usually based on visual interpretations of movement patterns (functional corridors) or habitat maps (structural corridors). We present a method for automated corridor mapping with morphological image processing, and...

Space Fence Ground-Based Radar System Increment 1 (Space Fence Inc 1)

DTIC Science & Technology

2015-12-01

Net - Centric Data Strategy and Net-Centric Services Strategy, and the principles and rules identified in the DoD IEA, excepting tactical and...Centric Data Strategy and Net- Centric Services Strategy, and the principles and rules identified in the DoD IEA, excepting tactical and non-IP...Strategy, and the principles and rules identified in the DoD IEA, excepting tactical and non-IP communi- cations. Compliant with TBD Space Fence must

Plank fence penetration into automobiles-implications for prevention initiatives.

PubMed

Procter, Levi; Bernard, Andrew; Ginn, Gary; Kearney, Paul; Pienkowski, David

2011-01-01

The wooden plank fence presents a deadly but unrecognized hazard to motorists. We hypothesize that fence plank injury is prevalent and results in significant morbidity and mortality. Databases of the University of Kentucky's Level I Trauma Center and the Fayette County Coroner were retrospectively analyzed over a 12-year period (1995-2006). One hundred and twenty-eight subjects were involved in vehicle contact with wooden plank fences. One hundred and twenty-three subjects were evaluated at the Emergency Department of our trauma center; 35 (27%) had a patient-plank interaction (PPI). Men (30/35) were more frequently involved (86%), and average age was 32.8 years. Thirty-two (91%) were drivers; 14/35 (40%) died from PPI-related injuries. The most common cause of death was blunt head trauma in 13 of these 14 fatally injured subjects (93%). This study provides new data underscoring the frequency, lethality, and economic consequences of this injury mechanism. Further research is needed to quantify the national prevalence of this problem and develop injury-mitigating strategies pertaining to roadway or fence design. © 2010 American Academy of Forensic Sciences.

A meta-analytic review of corridor effectiveness.

PubMed

Gilbert-Norton, Lynne; Wilson, Ryan; Stevens, John R; Beard, Karen H

2010-06-01

Using corridors for conservation is increasing despite a lack of consensus on their efficacy. Specifically, whether corridors increase movement of plants and animals between habitat fragments has been addressed on a case-by-case basis with mixed results. Because of the growing number of well-designed experiments that have addressed this question, we conducted a meta-analysis to determine whether corridors increase movement; whether corridor effectiveness differs among taxa; how recent changes in experimental design have influenced findings; and whether corridor effectiveness differs between manipulative and natural experiments. To conduct our meta-analysis, we analyzed 78 experiments from 35 studies using a conservative hierarchical Bayesian model that accounts for hierarchical and sampling dependence. We found a highly significant result that corridors increase movement between habitat patches by approximately 50% compared to patches that are not connected with corridors. We found that corridors were more important for the movement of invertebrates, nonavian vertebrates, and plants than they were for birds. Recent methodological advances in corridor experiments, such as controlling for the area added by corridors, did not influence whether corridors increased movement, whereas controlling for the distance between source and connected or unconnected recipient patches decreased movement through corridors. After controlling for taxa differences and whether studies controlled for distance in experimental design, we found that natural corridors (those existing in landscapes prior to the study) showed more movement than manipulated corridors (those created and maintained for the study). Our results suggest that existing corridors increase species movement in fragmented landscapes and that efforts spent on maintaining and creating corridors are worthwhile.

New properties of a fiber optic sensor in application of a composite fence for critical infrastructure protection

NASA Astrophysics Data System (ADS)

Zyczkowski, M.; Szustakowski, M.; Markowski, P.

2015-09-01

This paper presents a new solution of using the composite fence with a novel fiber optic modalmetric sensor integrated within its structure. The modalmetric sensor is based on changes in a transverse modal field which is generated at the output of a multimode fiber. By a spatial limitation of the transverse modal field observation to its fragment thereof, changes' transformation in the modal distribution into changes of the output signal amplitude is made. Due to a constant analysis of the structure output signal, detection of an external disorder is possible. Integration of optical fibers with the fence structure allows for an accurate reproduction of the fence movement onto the optical fiber by significantly improving sensitivity of the modalmetric fiber sensor structure.

14 CFR 93.307 - Minimum flight altitudes.

Code of Federal Regulations, 2013 CFR

2013-01-01

... feet MSL. (b) Minimum corridor altitudes—(1) Commercial air tours—(i) Zuni Point Corridors. 7,500 feet MSL. (ii) Dragon Corridor. 7,500 feet MSL. (2) Transient and general aviation operations—(i) Zuni Point Corridor. 10,500 feet MSL. (ii) Dragon Corridor. 10,500 feet MSL. (iii) Tuckup Corridor. 10,500...

14 CFR 93.307 - Minimum flight altitudes.

Code of Federal Regulations, 2014 CFR

2014-01-01

... feet MSL. (b) Minimum corridor altitudes—(1) Commercial air tours—(i) Zuni Point Corridors. 7,500 feet MSL. (ii) Dragon Corridor. 7,500 feet MSL. (2) Transient and general aviation operations—(i) Zuni Point Corridor. 10,500 feet MSL. (ii) Dragon Corridor. 10,500 feet MSL. (iii) Tuckup Corridor. 10,500...

Contamination Assessment Report, Site 1-7, Hydrazine Blending and Storage Facility. Version 3.2

DTIC Science & Technology

1988-09-01

Anaytca Laotris Rnc \\ R THE RTAIN A L CONT ATION C ow 93 ii416 ROCKY MOUNTAIN ARSENAL eCOMMERCE CITY, (’OLORADO *80022-2180 Best Avai~lable Copy...CONTAMINATION CLEANUP I THE INFORMATION AND CONCLUSIONS PRESENTED IN THIS REPORT REPRESENT THE OFFICIAL POSITION OF THE DEPARTMENT OF THE ARMY UNLESS... security fence and a barbed wire fence. These fenced areas are 450 feet (ft) apart, but the yards are connected by two overhead pipelines. The west yard

Final Environmental Assessment: Perimeter Fence Upgrade and Demolition of Two Sheds and Two Water Tanks, Lake Kickapoo Air Force Space Surveillance Station, Texas

DTIC Science & Technology

2012-11-01

to upgrade the existing barbed-wire fence with an eight-foot high chain-link fence with an outrigger on the top and demolish two sheds and two water...Pollutants NPDES National Pollutant Discharge Elimination System NRCS Natural Resources Conservation Service NRHP National Register of Historic Places...infrastructure. 1.1 BACKGROUND AND LOCATION The Air Force Space Surveillance System , known as the “space fence”, is a radar system that detects and

Evolved atmospheric entry corridor with safety factor

NASA Astrophysics Data System (ADS)

Liang, Zixuan; Ren, Zhang; Li, Qingdong

2018-02-01

Atmospheric entry corridors are established in previous research based on the equilibrium glide condition which assumes the flight-path angle to be zero. To get a better understanding of the highly constrained entry flight, an evolved entry corridor that considers the exact flight-path angle is developed in this study. Firstly, the conventional corridor in the altitude vs. velocity plane is extended into a three-dimensional one in the space of altitude, velocity, and flight-path angle. The three-dimensional corridor is generated by a series of constraint boxes. Then, based on a simple mapping method, an evolved two-dimensional entry corridor with safety factor is obtained. The safety factor is defined to describe the flexibility of the flight-path angle for a state within the corridor. Finally, the evolved entry corridor is simulated for the Space Shuttle and the Common Aero Vehicle (CAV) to demonstrate the effectiveness of the corridor generation approach. Compared with the conventional corridor, the evolved corridor is much wider and provides additional information. Therefore, the evolved corridor would benefit more to the entry trajectory design and analysis.

Habitat corridors facilitate genetic resilience irrespective of species dispersal abilities or population sizes.

PubMed

Christie, Mark R; Knowles, L Lacey

2015-06-01

Corridors are frequently proposed to connect patches of habitat that have become isolated due to human-mediated alterations to the landscape. While it is understood that corridors can facilitate dispersal between patches, it remains unknown whether corridors can mitigate the negative genetic effects for entire communities modified by habitat fragmentation. These negative genetic effects, which include reduced genetic diversity, limit the potential for populations to respond to selective agents such as disease epidemics and global climate change. We provide clear evidence from a forward-time, agent-based model (ABM) that corridors can facilitate genetic resilience in fragmented habitats across a broad range of species dispersal abilities and population sizes. Our results demonstrate that even modest increases in corridor width decreased the genetic differentiation between patches and increased the genetic diversity and effective population size within patches. Furthermore, we document a trade-off between corridor quality and corridor design whereby populations connected by high-quality habitat (i.e., low corridor mortality) are more resilient to suboptimal corridor design (e.g., long and narrow corridors). The ABM also revealed that species interactions can play a greater role than corridor design in shaping the genetic responses of populations to corridors. These results demonstrate how corridors can provide long-term conservation benefits that extend beyond targeted taxa and scale up to entire communities irrespective of species dispersal abilities or population sizes.

Habitat corridors facilitate genetic resilience irrespective of species dispersal abilities or population sizes

PubMed Central

Christie, Mark R; Knowles, L Lacey

2015-01-01

Corridors are frequently proposed to connect patches of habitat that have become isolated due to human-mediated alterations to the landscape. While it is understood that corridors can facilitate dispersal between patches, it remains unknown whether corridors can mitigate the negative genetic effects for entire communities modified by habitat fragmentation. These negative genetic effects, which include reduced genetic diversity, limit the potential for populations to respond to selective agents such as disease epidemics and global climate change. We provide clear evidence from a forward-time, agent-based model (ABM) that corridors can facilitate genetic resilience in fragmented habitats across a broad range of species dispersal abilities and population sizes. Our results demonstrate that even modest increases in corridor width decreased the genetic differentiation between patches and increased the genetic diversity and effective population size within patches. Furthermore, we document a trade-off between corridor quality and corridor design whereby populations connected by high-quality habitat (i.e., low corridor mortality) are more resilient to suboptimal corridor design (e.g., long and narrow corridors). The ABM also revealed that species interactions can play a greater role than corridor design in shaping the genetic responses of populations to corridors. These results demonstrate how corridors can provide long-term conservation benefits that extend beyond targeted taxa and scale up to entire communities irrespective of species dispersal abilities or population sizes. PMID:26029259

Cathedral house & crocker fence, Taylor Street east and north ...

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

Cathedral house & crocker fence, Taylor Street east and north elevations, perspective view from the northeast - Grace Cathedral, George William Gibbs Memorial Hall, 1051 Taylor Street, San Francisco, San Francisco County, CA

An evaluation of a mitigation strategy for deer-vehicle collisions

USGS Publications Warehouse

Bissonette, John A.; Rosa, Silvia

2012-01-01

High mule deer Odocoileus hemionus mortality in southwestern Utah led to the establishment of a mitigation strategy with two major objectives: 1) reduction of wildlife-vehicle collisions and 2) restoration of landscape connectivity to facilitate wildlife movement across the roaded landscape. During our study, we assessed the effectiveness of the mitigation measures in reducing mule deer mortality in the following ways: 1) we compared the number of deer-vehicle collisions in the newly fenced area with a control area without fencing; 2) we analyzed the ‘end-of-the-fence’ problem, defined here as increased mortality of mule deer at the ends of the 2.4-m high exclusion fences; and 3) we evaluated the frequency of animal crossings of the new underpasses using remotely-sensed cameras and compared them with crossing frequency rates for a 20-year-old control underpass. We compared six years of pre-construction mortality (during 1998-2003) with two years of post-construction data on mortality (during 2005-2006) and found a 98.5% decline in deer mortalities in the treatment (i.e. fenced, jump-outs and underpasses) vs a 2.9% decline in the control (i.e. no fences, no jump-outs and no underpasses). We detected no end-of-the-fence problems related to deer mortality. Migratory movements during fall and spring were clearly reflected in the use of underpass. Overall results demonstrated that the mitigation strategy was effective and reduced the number of deer-vehicle accidents, while allowing wildlife movement across the landscape.

Experiments and Dynamic Finite Element Analysis of a Wire-Rope Rockfall Protective Fence

NASA Astrophysics Data System (ADS)

Tran, Phuc Van; Maegawa, Koji; Fukada, Saiji

2013-09-01

The imperative need to protect structures in mountainous areas against rockfall has led to the development of various protection methods. This study introduces a new type of rockfall protection fence made of posts, wire ropes, wire netting and energy absorbers. The performance of this rock fence was verified in both experiments and dynamic finite element analysis. In collision tests, a reinforced-concrete block rolled down a natural slope and struck the rock fence at the end of the slope. A specialized system of measuring instruments was employed to accurately measure the acceleration of the block without cable connection. In particular, the performance of two energy absorbers, which contribute also to preventing wire ropes from breaking, was investigated to determine the best energy absorber. In numerical simulation, a commercial finite element code having explicit dynamic capabilities was employed to create models of the two full-scale tests. To facilitate simulation, certain simplifying assumptions for mechanical data of each individual component of the rock fence and geometrical data of the model were adopted. Good agreement between numerical simulation and experimental data validated the numerical simulation. Furthermore, the results of numerical simulation helped highlight limitations of the testing method. The results of numerical simulation thus provide a deeper understanding of the structural behavior of individual components of the rock fence during rockfall impact. More importantly, numerical simulations can be used not only as supplements to or substitutes for full-scale tests but also in parametric study and design.

Nitrogen mineralization in the aspen ecosystem

Treesearch

M. C. Amacher; A. D. Johnson; T. Christopherson; D. E. Kutterer; D. L. Bartos; J. Kotuby-Amacher

1999-01-01

Aspen (Populus tremuloides) are in decline throughout the interior western U.S. because of conifer invasion, fire suppression, and overbrowsing by domestic livestock and native ungulates. Aspen restoration requires disturbances such as fire or cutting and exclosures to protect against overbrowsing. We measured the effects of the 1996 Pole Creek fire, Fishlake NF, UT on...

Relationships between cattle and biodiversity revealed by the Kenya Long-term Exclosure Experiment (KLEE)

USDA-ARS?s Scientific Manuscript database

On rangelands worldwide, cattle interact with many forms of biodiversity, most obviously with vegetation and other large herbivores. Since 1995, we have been manipulating the presence of cattle, medium-sized herbivores, and mega-herbivores (elephants and giraffes) in a series of eighteen 4ha (10-acr...

Modification of mixed-conifer forests by ruminant herbivores in the Blue Mountains ecological province.

Treesearch

Robert A. Riggs; Arthur R. Tiedemann; John G. Cook; et al.

2000-01-01

Secondary plant succession and the accumulation of biomass and nutrients were documented at seven ruminant exclosures in Abies and Pseudotsuga forests variously disturbed by logging, burning, and grass seeding. Long-term (25 or more years) foraging by Rocky Mountain mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus...

Long-term aspen exclosures in the Yellowstone ecosystem

Treesearch

Charles E. Kay

2001-01-01

Aspen has been declining in the Yellowstone Ecosystem for more than 80 years. Some authors have suggested that aspen is a marginal plant community in Yellowstone and that recent climatic variation has adversely affected aspen, while others contend that excessive browsing by native ungulates is primarily responsible for aspen's widespread decline. To test these...

Low-quality habitat corridors as movement conduits for two butterfly species.

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

Haddad, Nick, M.; Tewksbury, Joshua, J.

2005-01-01

Haddad, Nick, M, and Joshua J. Tewksbury. Low-quality habitat corridors as movement conduits for two butterfly species. Ecol. Apps. 15(1):250-257. Abstract. Corridors are a primary conservation tool to increase connectivity, promote individual movement, and increase gene flow among populations in fragmented landscapes. The establishment of effective conservation corridors will depend on constructing or pre-serving connecting habitat that attracts dispersing individuals. Yet, it remains unclear whether corridors must necessarily be composed of high-quality habitat to be effective and promote dispersal and gene flow. We address this issue with two mobile, open-habitat butterfly species, Junonia coenia HuÈbner and Euptoieta claudia Cramer. Usingmore » experimental landscapes created explicitly to examine the effects of corridors on dispersal rates, we show that open-habitat corridors can serve as dispersal conduits even when corridors do not support resident butterfly populations. Both butterfly species were rare near forest edges and equally rare in narrow corridors, yet both species dispersed more often between patches connected by these corridors than between isolated patches. At least for species that can traverse corridors within a generation, corridor habitat may be lower in quality than larger patches and still increase dispersal and gene flow. For these species, abundance surveys may not accurately represent the conservation value of corridors.« less

The ability of ewes with lambs to learn a virtual fencing system.

PubMed

Brunberg, E I; Bergslid, I K; Bøe, K E; Sørheim, K M

2017-11-01

The Nofence technology is a GPS-based virtual fencing system designed to keep sheep within predefined borders, without using physical fences. Sheep wearing a Nofence collar receive a sound signal when crossing the virtual border and a weak electric shock if continuing to walk out from the virtual enclosure. Two experiments testing the functionality of the Nofence system and a new learning protocol is described. In Experiment 1, nine ewes with their lambs were divided into groups of three and placed in an experimental enclosure with one Nofence border. During 2 days, there was a physical fence outside the border, during Day 3 the physical fence was removed and on Day 4, the border was moved to the other end of the enclosure. The sheep received between 6 and 20 shocks with an average of 10.9±2.0 (mean±SE) per ewe during all 4 days. The number of shocks decreased from 4.38±0.63 on Day 3 (when the physical fence was removed) to 1.5±0.71 on Day 4 (when the border was moved). The ewes spent on average 3%, 6%, 46% and 9% of their time outside the border on Days 1, 2, 3 and 4, respectively. In Experiment 2, 32 ewes, with and without lambs, were divided into groups of eight and placed in an experimental enclosure. On Day 1, the enclosure was fenced with three physical fences and one virtual border, which was then increased to two virtual borders on Day 2. To continue to Day 3, when there was supposed to be three virtual borders on the enclosure, at least 50% of the ewes in a group should have received a maximum of four shocks on Day 2. None of the groups reached this learning criterion and the experiment ended after Day 2. The sheep received 4.1±0.32 shocks on Day 1 and 4.7±0.28 shocks on Day 2. In total, 71% of the ewes received the maximum number of five shocks on Day 1 and 77% on Day 2. The individual ewes spent between 0% and 69.5% of Day 1 in the exclusion zone and between 0% and 64% on Day 2. In conclusion, it is too challenging to ensure an efficient learning and hence, animal welfare cannot be secured. There were technical challenges with the collars that may have affected the results. The Nofence prototype was unable to keep the sheep within the intended borders, and thus cannot replace physical fencing for sheep.

Corridor Use Predicted from Behaviors at Habitat Boundaries.

PubMed

Haddad, Nick M

1999-02-01

Through empirical studies and simulation, I demonstrate how simple behaviors can be used in lieu of detailed dispersal studies to predict the effects of corridors on interpatch movements. Movement paths of three butterfly species were measured in large (1.64 ha) experimental patches of open habitat, some of which were connected by corridors. Butterflies that "reflected" off boundaries between open patches and the surrounding forest also emigrated from patches through corridors at rates higher than expected from random movement. This was observed for two open-habitat species, Eurema nicippe and Phoebis sennae; however, edges and corridors had no effect on a habitat generalist, Papilio troilus. Behaviorally based simulation models, which departed from correlated random walks only at habitat boundaries, predicted that corridors increase interpatch movement rates of both open-habitat species. Models also predicted that corridors have proportionately greater effects as corridor width increases, that movement rates increase before leveling off as corridor width increases, and that corridor effects decrease as patch size increases. This study suggests that corridors direct movements of habitat-restricted species and that local behaviors may be used to predict the conservation potential of corridors in fragmented landscapes.

John Day River Sub-Basin Fish Habitat Enhancement Project; 2008 Annual Report

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

Powell, Russ M.; Alley, Pamela D.; Goin Jr, Lonnie

Work undertaken in 2008 included: (1) Seven new fence projects were completed thereby protecting approximately 10.97 miles of streams with 16.34 miles of riparian fence; (2) Renewal of one expired lease was completed thereby continuing to protect 0.75 miles of stream with 1.0 mile of riparian fence. (3) Maintenance of all active project fences (106.54 miles), watergaps (78), spring developments (33) were checked and repairs performed; (3) Planted 1000 willow/red osier on Fox Creek/Henslee property; (4) Planted 2000 willows/red osier on Middle Fork John Day River/Coleman property; (5) Planted 1000 willow/red osier cuttings on Fox Creek/Johns property; (6) Since themore » initiation of the Fish Habitat Project in 1984 we have 126.86 miles of stream protected using 211.72 miles of fence protecting 5658 acres. The purpose of the John Day Fish Habitat Enhancement Program is to enhance production of indigenous wild stocks of spring Chinook and summer steelhead within the sub basin through habitat protection, enhancement and fish passage improvement. The John Day River system supports the largest remaining wild runs of spring chinook salmon and summer steelhead in Northeast Oregon.« less

Epigenetic response to environmental change: DNA methylation varies with invasion status.

PubMed

Schrey, Aaron W; Robbins, Travis R; Lee, Jacob; Dukes, David W; Ragsdale, Alexandria K; Thawley, Christopher J; Langkilde, Tracy

2016-04-01

Epigenetic mechanisms may be important for a native species' response to rapid environmental change. Red Imported Fire Ants ( Solenopsis invicta Santschi, 1916) were recently introduced to areas occupied by the Eastern Fence Lizard ( Sceloporus undulatus Bosc & Daudin, 1801). Behavioral, morphological and physiological phenotypes of the Eastern Fence Lizard have changed following invasion, creating a natural biological system to investigate environmentally induced epigenetic changes. We tested for variation in DNA methylation patterns in Eastern Fence Lizard populations associated with different histories of invasion by Red Imported Fire Ants. At methylation sensitive amplified fragment length polymorphism loci, we detected a higher diversity of methylation in Eastern Fence Lizard populations from Fire Ant uninvaded versus invaded sites, and uninvaded sites had higher methylation. Our results suggest that invasive species may alter methylation frequencies and the pattern of methylation among native individuals. While our data indicate a high level of intrinsic variability in DNA methylation, DNA methylation at some genomic loci may underlie observed phenotypic changes in Eastern Fence Lizard populations in response to invasion of Red Imported Fire Ants. This process may be important in facilitating adaptation of native species to novel pressures imposed by a rapidly changing environment.

CHICKEN COOP BEHIND FENCED YARD AND (REAR) OF BARBEQUE PIT, ...

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

CHICKEN COOP BEHIND FENCED YARD AND (REAR) OF BARBEQUE PIT, LOOKING NORTH - Irvine Ranch Agricultural Headquarters, Carillo Tenant House, Southwest of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

Stone wall and ornamental iron fence extending along Gray's Ferry ...

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

Stone wall and ornamental iron fence extending along Gray's Ferry Avenue between the north and south gate lodges, looking southwest. - U. S. Naval Asylum, Biddle Hall, Gray's Ferry Avenue, Philadelphia, Philadelphia County, PA

2. Historic American Buildings Survey E. W. Russell, Photographer, September ...

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

2. Historic American Buildings Survey E. W. Russell, Photographer, September 3, 1936 FENCE IN FRONT, GOLDSBY HOME - 452 GOVERNMENT STREET - J. W. Goldsby House & Iron Fence, 452 Government Street, Mobile, Mobile County, AL

Land degradation and restoration: The North African experiences

NASA Astrophysics Data System (ADS)

Hirche, azziz; Salamani, mostefa; Boughani, abdelmadjid; Belala, fahima; Essafi, bouajila; Gashut, el-hadi; Hourizi, ratiba; Grandi, mohamed; Ain hamouda, tahar

2017-04-01

The North African steppe, a key area whose economic activity is based on agro-pastoralism, covers 75 million hectares. This steppe underwent significant degradation in the eighties. The combination of severe droughts, the most important of the century, with a peak between 1982-1987 and 2000-2005 and an exponential increase in livestock had a catastrophic impact on pastoral resources. The "alfa" (Stipa tenacissima), an emblematic species of these arid lands, what was called "sea to alfa" is now disappearing. Vegetation cover, which was more than 30% before 1980, is now less than 15%. Concerning the phytomasse, the aboveground dry matter production which exceeds 1ton ha-1 in 1980, is now less than 480 kg.ha-1. At the same time, the agricultural areas in the steppe area, previously marginal, are steadily increasing and reaching several million hectares. This cereal production takes place to the detriment of natural ranges with very low yields (less than 5 quintals per hectare). In response to this deterioration, the North African governments, from the seventies defined different strategies to manage and restore the ecosystems. These ones, based on a socio-economic approach were in summary: (1) To increase pastoral and agricultural production; (2) to reduce livestock; (3) to combine the first two. Several options were considered. The main ones were planting, collecting water for livestock and agriculture and finally installing exclosures. Agro-forestry plantations were carried out with different species, particularly the genus Atriplex, Medicago and Opuntia. Small hydraulic entities were also built to increase the planted area. The exclosures were established on millions of acres. We discuss the relevance and success rate of these works. The economics and biological impacts (biodiversity, production) are assessed. As a result, the government's strategies are not coherent and sometimes seem at odds with the objectives of combating desertification. Worse yet, in some cases, through their inconsistencies some governments seem paradoxically to be supporting the steppe degradation. This underlines the complexity of the problem. Keywords: North Africa, Steppe, Overgrazing, Exclosures, Plantations, Desertification.

Ungulates increase forest plant species richness to the benefit of non-forest specialists.

PubMed

Boulanger, Vincent; Dupouey, Jean-Luc; Archaux, Frédéric; Badeau, Vincent; Baltzinger, Christophe; Chevalier, Richard; Corcket, Emmanuel; Dumas, Yann; Forgeard, Françoise; Mårell, Anders; Montpied, Pierre; Paillet, Yoan; Picard, Jean-François; Saïd, Sonia; Ulrich, Erwin

2018-02-01

Large wild ungulates are a major biotic factor shaping plant communities. They influence species abundance and occurrence directly by herbivory and plant dispersal, or indirectly by modifying plant-plant interactions and through soil disturbance. In forest ecosystems, researchers' attention has been mainly focused on deer overabundance. Far less is known about the effects on understory plant dynamics and diversity of wild ungulates where their abundance is maintained at lower levels to mitigate impacts on tree regeneration. We used vegetation data collected over 10 years on 82 pairs of exclosure (excluding ungulates) and control plots located in a nation-wide forest monitoring network (Renecofor). We report the effects of ungulate exclusion on (i) plant species richness and ecological characteristics, (ii) and cover percentage of herbaceous and shrub layers. We also analyzed the response of these variables along gradients of ungulate abundance, based on hunting statistics, for wild boar (Sus scrofa), red deer (Cervus elaphus) and roe deer (Capreolus capreolus). Outside the exclosures, forest ungulates maintained higher species richness in the herbaceous layer (+15%), while the shrub layer was 17% less rich, and the plant communities became more light-demanding. Inside the exclosures, shrub cover increased, often to the benefit of bramble (Rubus fruticosus agg.). Ungulates tend to favour ruderal, hemerobic, epizoochorous and non-forest species. Among plots, the magnitude of vegetation changes was proportional to deer abundance. We conclude that ungulates, through the control of the shrub layer, indirectly increase herbaceous plant species richness by increasing light reaching the ground. However, this increase is detrimental to the peculiarity of forest plant communities and contributes to a landscape-level biotic homogenization. Even at population density levels considered to be harmless for overall plant species richness, ungulates remain a conservation issue for plant community composition. ©2017 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Space Fence PDR Concept Development Phase

NASA Astrophysics Data System (ADS)

Haines, L.; Phu, P.

2011-09-01

The Space Fence, a major Air Force acquisition program, will become the dominant low-earth orbit uncued sensor in the space surveillance network (SSN). Its primary objective is to provide a 24/7 un-cued capability to find, fix, and track small objects in low earth orbit to include emerging and evolving threats, as well as the rapidly growing population of orbital debris. Composed of up to two geographically dispersed large-scale S-band phased array radars, this new system-of-systems concept will provide comprehensive Space Situational Awareness through net-centric operations and integrated decision support. Additionally, this program will facilitate cost saving force structure changes in the SSN, specifically including the decommissioning of very-high frequency VHF Air Force Space Surveillance System (AFSSS). The Space Fence Program Office entered a Preliminary Design Review (PDR) concept development phase in January 2011 to achieve the delivery of the Initial Operational Capability (IOC) expected in FY17. Two contractors were awarded to perform preliminary system design, conduct radar performance analyses and evaluations, and develop a functional PDR radar system prototype. The key objectives for the Phase A PDR effort are to reduce Space Fence total program technical, cost, schedule, and performance risk. The overall program objective is to achieve a preliminary design that demonstrates sufficient technical and manufacturing maturity and that represents a low risk, affordable approach to meet the Space Fence Technical Requirements Document (TRD) requirements for the final development and production phase to begin in 3QFY12. This paper provides an overview of the revised Space Fence program acquisition strategy for the Phase-A PDR phase to IOC, the overall program milestones and major technical efforts. In addition, the key system trade studies and modeling/simulation efforts undertaken during the System Design Requirement (SDR) phase to address and mitigate technical challenges of the Space Fence System will also be discussed. Examples include radar system optimization studies, modeling and simulation for system performance assessment, investigation of innovative Astrodynamics algorithms for initial orbit determination and observation correlation.

Bioassay evaluation of residual activity of attractive toxic sugar-treated barrier fence in the control of Phlebotomus papatasi (Diptera: Psychodidae).

PubMed

Saghafipour, Abedin; Vatandoost, Hassan; Zahraei-Ramazani, Ali Reza; Yaghoobi-Ershadi, Mohammad Reza; Rassi, Yavar; Shirzadi, Mohammad Reza; Akhavan, Amir Ahmad

2016-01-01

Phlebotomus papatasi is the main vector of the zoonotic cutaneous leishmaniasis (ZCL) in Qom Province and many other provinces of Iran. Attractive toxic sugar baits (ATSB) treated barrier fence is one of the new methods for controlling the vectors such as sandflies. The present study was designed to evaluate the residual activity of ATSB-treated barrier fence that was used in control of P. papatasi. Following the selection of villages in Markazi district of Qom Province, central Iran during 2015 for ATSB and ASB (bait containing no active ingredient) methods; barrier fences on the ground in front of the rodent's colony were installed. A total of four conical tubes were installed and fixed on surfaces of treated barrier net of dimension 25 Χ 25 cm at biweekly interval. In each conical tube, 10 sand flies were released and after 3 min of exposure they were transferred to sterile cups. After 24 h, the obtained results were recorded according to the survival and mortality rate of sandflies. These tests were carried out five days after the installation of barrier fences, and repeated every 15 days until the mortality rate decreased to 60-65%. The bioassay tests results showed that the mortality rate of P. papatasi on ATSB-treated barrier fence for 5, 15, 30 and 45 days after spraying was 100, 95.83, 88.18 and 66.67% respectively, which decreased to 50.83% after 60 days. Persistence and residual activity of the active ingredient of the bait in the hot and dry climatic conditions of Qom Province remained significantly effective for at most 45 days, which subsequently decreased at a high rate. Hence, every 45 days barrier fences need to be impregnated with ATSB bait. The method also appeared cost-effective and could be practical in implementation of vector control programmes against ZCL.

GATE AND FLANKING FENCE AT ENTRANCE TO MEMORIAL WALK. VIEW ...

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

GATE AND FLANKING FENCE AT ENTRANCE TO MEMORIAL WALK. VIEW TO NORTHEAST. - Rock Island National Cemetery, Rock Island Arsenal, 0.25 mile north of southern tip of Rock Island, Rock Island, Rock Island County, IL

12. Railing Detail for Dam Nos. 3 and 4, Fence ...

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

12. Railing Detail for Dam Nos. 3 and 4, Fence Detail for Reservoir Nos. 3 and 4, Single Lamp Details, Triple Lamp Details - Washington Park Reservoirs, 2403 SW Jefferson Street, Portland, Multnomah County, OR

Analysis of Potential Energy Corridors Proposed by the Western Electricity Coordinating Council

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

Kuiper, James A.; Cantwell, Brian J.; Hlava, Kevin J.

2014-02-24

This report, Analysis of Potential Energy Corridors Proposed by the Western Electricity Coordinating Council (WECC), was prepared by the Environmental Science Division of Argonne National Laboratory (Argonne). The intent of WECC’s work was to identify planning-level energy corridors that the Department of Energy (DOE) and its affiliates could study in greater detail. Argonne was tasked by DOE to analyze the WECC Proposed Energy Corridors in five topic areas for use in reviewing and revising existing corridors, as well as designating additional energy corridors in the 11 western states. In compliance with Section 368 of the Energy Policy Act of 2005more » (EPAct), the Secretaries of Energy, Agriculture, and the Interior (Secretaries) published a Programmatic Environmental Impact Statement in 2008 to address the proposed designation of energy transport corridors on federal lands in the 11 western states. Subsequently, Records of Decision designating the corridors were issued in 2009 by the Bureau of Land Management (BLM) and the U.S. Forest Service (USFS). The 2012 settlement of a lawsuit, brought by The Wilderness Society and others against the United States, which identified environmental concerns for many of the corridors requires, among other things, periodic reviews of the corridors to assess the need for revisions, deletions, or additions. A 2013 Presidential Memorandum requires the Secretaries to undertake a continuing effort to identify and designate energy corridors. The WECC Proposed Energy Corridors and their analyses in this report provide key information for reviewing and revising existing corridors, as well as designating additional energy corridors in the 11 western states. Load centers and generation hubs identified in the WECC analysis, particularly as they reflect renewable energy development, would be useful in reviewing and potentially updating the designated Section 368 corridor network. Argonne used Geographic Information System (GIS) technology to analyze the proposed energy corridors in the WECC report in five topic areas: Federal land jurisdiction, Existing Section 368 corridors, Existing transmission lines, Previously studied corridor locations, and Protected areas. Analysis methods are explained and tables and maps are provided to describe the results of the analyses in all five topic areas. WECC used a rational approach to connecting the hubs it identified, although there may be opportunities for adapting some of the proposed WECC routes to previously designated Section 368 corridors, for example: The WECC proposed energy corridors are in fact centerlines of proposed routes connecting hubs of various descriptions related to electric energy transmission. Although the centerlines were sited to avoid sensitive areas, infrastructure proposed within actual pathways or corridors defined by the centerlines would sometimes affect lands where such development would not normally be allowed, such as National Parks and Monuments, National Wildlife Refuges, and Wilderness Areas. Many WECC proposed energy corridors are sited along centerlines of existing roads, including Interstate Highways, where in some cases additional width to accommodate energy transmission infrastructure may not be available. Examples include the WECC Proposed Corridor along Interstate 70 through Glenwood Canyon in Colorado, and along U.S. Highway 89 across Glen Canyon Dam in Arizona. Several WECC proposed energy corridors are parallel to designated Section 368 corridors that have already cleared the preliminary steps to right-of-way approval. In many of these cases, the WECC hub connection objectives can be met more efficiently by routing on the designated Section 368 corridors.« less

The Solid-Phase Synthesis of an Fe-N-C Electrocatalyst for High-Power Proton-Exchange Membrane Fuel Cells.

PubMed

Liu, Qingtao; Liu, Xiaofang; Zheng, Lirong; Shui, Jianglan

2018-01-26

The environmentally friendly synthesis of highly active Fe-N-C electrocatalysts for proton-exchange membrane fuel cells (PEMFCs) is desirable but remains challenging. A simple and scalable method is presented to fabricate Fe II -doped ZIF-8, which can be further pyrolyzed into Fe-N-C with 3 wt % of Fe exclusively in Fe-N 4 active moieties. Significantly, this Fe-N-C derived acidic PEMFC exhibits an unprecedented current density of 1.65 A cm -2 at 0.6 V and the highest power density of 1.14 W cm -2 compared with previously reported NPMCs. The excellent PEMFC performance can be attributed to the densely and atomically dispersed Fe-N 4 active moieties on the small and uniform catalyst nanoparticles. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gender differences in patellofemoral load during the epee fencing lunge.

PubMed

Sinclair, J; Bottoms, L

2015-01-01

Clinical analyses have shown that injuries and pain linked specifically to fencing training/competition were prevalent in 92.8% of fencers. Patellofemoral pain is the most common chronic injury in athletic populations and females are considered to be more susceptible to this pathology. This study aimed to examine gender differences in patellofemoral contact forces during the fencing lunge. Patellofemoral contact forces were obtained from eight male and eight female club level epee fencers using an eight-camera 3D motion capture system and force platform data as they completed simulated lunges. Independent t-tests were performed on the data to determine whether gender differences in patellofemoral contact forces were present. The results show that females were associated with significantly greater patellofemoral contact force parameters in comparison with males. This suggests that female fencers may be at greater risk from patellofemoral pathology as a function of fencing training/competition.

An evaluation of Brifen wire rope safety fence.

DOT National Transportation Integrated Search

2013-01-01

Three : - : strand : cable barriers were first developed in the 1960s and found to have several desirable : characteristics as compared to other roadside barriers such as guard rail : . : Brifen Wire Rope Safety Fence is : a four strand woven wire...

Installation of straw barriers and silt fences.

DOT National Transportation Integrated Search

1976-01-01

The most common types of temporary sediment control structures used by the Virginia Department of Highways and Transportation are straw barriers and silt fences. Based on observations made in Virginia and other parts of the nation, filter barriers ha...

DETAIL OF FENCE FLANKING GATE AT ENTRANCE TO MEMORIAL WALK. ...

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

DETAIL OF FENCE FLANKING GATE AT ENTRANCE TO MEMORIAL WALK. VIEW TO NORTHEAST. - Rock Island National Cemetery, Rock Island Arsenal, 0.25 mile north of southern tip of Rock Island, Rock Island, Rock Island County, IL

42 CFR 423.336 - Risk-sharing arrangements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... payments to a Part D sponsor subject to risk—(1) Adjusted allowable risk corridor costs. For purposes of this paragraph, the term adjusted allowable risk corridor costs means— (i) The allowable risk corridor... coverage year. (2) Establishment of risk corridors. (i) Risk corridors. For each year, CMS establishes a...

Corridors affect plants, animals, and their interactions in fragmented landscapes

PubMed Central

Tewksbury, Joshua J.; Levey, Douglas J.; Haddad, Nick M.; Sargent, Sarah; Orrock, John L.; Weldon, Aimee; Danielson, Brent J.; Brinkerhoff, Jory; Damschen, Ellen I.; Townsend, Patricia

2002-01-01

Among the most popular strategies for maintaining populations of both plants and animals in fragmented landscapes is to connect isolated patches with thin strips of habitat, called corridors. Corridors are thought to increase the exchange of individuals between habitat patches, promoting genetic exchange and reducing population fluctuations. Empirical studies addressing the effects of corridors have either been small in scale or have ignored confounding effects of increased habitat area created by the presence of a corridor. These methodological difficulties, coupled with a paucity of studies examining the effects of corridors on plants and plant–animal interactions, have sparked debate over the purported value of corridors in conservation planning. We report results of a large-scale experiment that directly address this debate. In eight large-scale experimental landscapes that control for patch area and test alternative mechanisms of corridor function, we demonstrate that corridors not only increase the exchange of animals between patches, but also facilitate two key plant–animal interactions: pollination and seed dispersal. Our results show that the beneficial effects of corridors extend beyond the area they add, and suggest that increased plant and animal movement through corridors will have positive impacts on plant populations and community interactions in fragmented landscapes. PMID:12239344

Evaluation of the effect of buccal corridor size on smile attractiveness.

PubMed

Oshagh, Morteza; Zarif, Najafi H; Bahramnia, F

2010-01-01

an attractive smile helps people feel more self-confident and look younger. One of the more controversial aspects of smile attractiveness pertains to buccal corridor size. There is no previous study by those with artistic knowledge that has assessed the asthetic considerations of buccal corridor size. The purpose of this study was to observe whether the size of buccal corridors has an impact on smile attractiveness evaluated by lay people, dental students, and art students. colored post-treatment photograph with posed smiles of two subjects (one male, one female) were selected. The maxillary posterior dentitions were digitally altered to produce different buccal corridor sizes: narrow (28% buccal corridor), medium-narrow (22% buccal corridor), medium-broad (10% buccal corridor), and broad (2% buccal corridor). The 5 images of each subject were paired into 11 possible combinations and presented to three group: art students, dental students, and lay people, who compared the two images in each pair of smile attractiveness. The statistical test used were Wilcoxon signed rank and Mann-Whitney test. minimal and excessive buccal corridors were the least attractive when judged by three groups. All groups preferred smaller buccal corridors for the male subject and larger buccal corridors for the female subject. No significant judging differences were found between male and female judges from among art and dental students. minimal or excessive buccal corridor should be included in the problem list during orthodontic diagnosis and treatment planning.

Host specificity of Aphelinus species considered for introduction to control Diuraphis noxia

USDA-ARS?s Scientific Manuscript database

DIURAPHIS NOXIA has become a major pest of wheat and barley since it was detected in the western USA in 1986. DIURAPHIS NOXIA is seldom a pest in Eurasia, its area of origin. Field surveys and exclosure experiments showed that natural enemies can limit D. NOXIA abundance in Eurasia. Among the most i...

Long-term growth of eight legumes introduced at three forest locations in southwest Oregon

Treesearch

Richard E. Miller; Ray Zalunardo

1979-01-01

Using nitrogen-fixing plants in forestry becomes financially more attractive as the costs of fertilizers and their application continue to increase. Eight legume cultivars were screened for suitability in Douglas-fir forests of southwest Oregon. The legumes were sown on concurrently fertilized and unfertilized plots within deer exclosures in three logged and burned...

Effects of deer exclosures on oak regeneration in closed-canopy stands

Treesearch

Angela M. Yuska; Kim C. Steiner; James C. Finley

2008-01-01

Studies of the effects of high deer densities on forest regeneration have shown altered species composition and reduced diversity in stands regenerating after harvest. The effects of browsing in fully stocked, undisturbed stands are less well known but important, as establishment of seedlings of oaks and other species prior to disturbance is very important for self-...

THE RELATIVE IMPORTANCE OF NUTRIENT ENRICHMENT AND HERBIVORY ON MACROALGAL COMMUNITIES NEAR NORMAN'S POND CAY, EXUMAS CAYS, BAHAMAS: A "NATURAL" ENRICHMENT EXPERIMENT. (R830414)

EPA Science Inventory

The simultaneous effects of grazing and nutrient enrichment on macroalgal communities were experimentally investigated using plastic mesh enclosure/exclosure cages along a natural nutrient (DIN, SRP) gradient from the discharge of a tidal mangrove creek on the west side of Nor...

Small mammal populations in a grazed and ungrazed riparian habitat in Nevada

Treesearch

Dean E. Medin; Warren P. Clary

1989-01-01

Small mammal populations were compared between a grazed habitat and a comparable adjoining habitat protected from grazing by an exclosure. Composition, naive densiiy, standing crop biomass, species diversity, and other attributes of the small mammal communities were assessed. More species and higher numbers of most small mammals were found in the ungrazed habitat....

Livestock Grazing, Golden Trout, and Streams in the Golden Trout Wilderness, California: Impacts and Management Implications

Treesearch

R. Knapp; K. Matthews

1996-01-01

Impacts of livestock grazing on California golden trout Oncorhynchus rnykiss aguabonita and their habitat were studied inside and outside of livestock exclosures in the Golden Trout Wilderness, California. In two consecutive years, the majority of stream physical characteristics showed large differences between grazed and ungrazed areas, and the directions of these...

I-880 Integrated Corridor Management Concept of Operation : Final Submittal: Concept of Operations for the I-880 Corridor in Oakland, California

DOT National Transportation Integrated Search

2008-03-31

This report describes the draft Concept of Operations that has been developed for the Integrated Corridor Mobility (ICM) program by the I-880 corridor team. The I-880 corridor team has defined this Concept of Operations (ConOps) based on two primary ...

[Perception and attitude of rural community to the construction of Asian elephant conservation corridors in Xishuangbanna].

PubMed

Li, Zheng-Ling; Chen, Ming-Yong; Wu, Zhao-Lu; Wang, Qian; Dong, Yong-Hua

2009-06-01

By using contingent valuation method (CVM), an investigation was made from November 2007 to March 2008 on the perception and attitude of 196 households in 5 villages within 2 planned Asian elephant conservation corridors in Xishuangbanna to the construction of the corridors. 80.61% of the interviewees conditionally supported the corridors construction. The main factors affecting the interviewees' support willingness included their education level, per capita income, and perceptions to Asian elephant protection, human-elephant relations, and corridor utilization patterns and its beneficiaries, among which, the interviewees' awareness of Asian elephant conservation, corridor utilization patterns, and corridor beneficiaries had strong influence on the support willingness, with the correlation coefficient being 0.231, 0.236, and -0.304, respectively. The rural community holding the land tenure played a key role in the corridors construction. To effectively design and planning the construction of biological conservation corridor, it is necessary to have a deep understanding on the perceptions and attitudes of rural community to the construction of the corridor and to obtain their support and participation for this construction.

Corridor use by diverse taxa.

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

Haddad, Nick, M.; Browne, David, R.; Cunningham, Alan

2003-01-01

Haddad, N.M., D.R. Browne, A. Cunningham, B.J. Danielson, D.J. Levey, S. Sargent, and T. Spira. 2003. Corridor use by diverse taxa. Ecology, 84(3):609-615. One of the most popular approaches for maintaining populations and conserving biodiversity in fragmented landscapes is to retain or create corridors that connect otherwise isolated habitat patches. Working in large-scale, experimental landscapes in which open-habitat patches and corridors were created by harvesting pine forest, we showed that corridors direct movements of different types of species, including butterflies, small mammals, and bird dispersed plants, causing higher movement between connected than between unconnected patches. Corridors directed the movement ofmore » all 10 species studied, with all corridor effect sizes >68%. However, this corridor effect was significant for five species, not significant for one species, and inconclusive for four species because of small sample sizes. Although we found no evidence that corridors increase emigration from a patch, our results show that movements of disparate taxa with broadly different life histories and functional roles are directed by corridors.« less

Evaluation of filter fabrics for use in silt fences.

DOT National Transportation Integrated Search

1980-01-01

The study reported was initiated to develop tests simulating field conditions that could be used to develop information for the formulation of specifications for use in purchasing filter fabrics to be used to construct silt fences. Fifteen fabrics we...

Fe/N/C composite in Li-O2 battery: studies of catalytic structure and activity toward oxygen evolution reaction.

PubMed

Shui, Jiang-Lan; Karan, Naba K; Balasubramanian, Mahalingam; Li, Shu-You; Liu, Di-Jia

2012-10-10

Atomically dispersed Fe/N/C composite was synthesized and its role in controlling the oxygen evolution reaction during Li-O(2) battery charging was studied by use of a tetra(ethylene glycol) dimethyl ether-based electrolyte. Li-O(2) cells using Fe/N/C as the cathode catalyst showed lower overpotentials than α-MnO(2)/carbon catalyst and carbon-only material. Gases evolved during the charge step contained only oxygen for Fe/N/C cathode catalyst, whereas CO(2) was also detected in the case of α-MnO(2)/C or carbon-only material; this CO(2) was presumably generated from electrolyte decomposition. Our results reiterate the catalytic effect in reducing overpotentials, which not only enhances battery efficiency but also improves its lifespan by reducing or eliminating electrolyte decomposition. The structure of the Fe/N/C catalyst was characterized by transmission electron microscopy, scanning transmission electron microscopy, inductively coupled plasma optical emission spectroscopy, and X-ray absorption spectroscopy. Iron was found to be uniformly distributed within the carbon matrix, and on average, Fe was coordinated by 3.3 ± 0.6 and 2.2 ± 0.3 low Z elements (C/N/O) at bond distances of ~1.92 and ~2.09 Å, respectively.

Preliminary effects of streambank fencing of pasture land on the quality of surface water in a small watershed in Lancaster County, Pennsylvania

USGS Publications Warehouse

Galeone, Daniel G.

2000-01-01

The use of fencing to exclude pastured animals from streams has been recognized as an agricultural best-management practice. Streambank fencing was installed in a small basin within the Mill Creek Watershed of Lancaster County, Pa., during summer 1997 to evaluate the effectiveness of fencing on surface-water quality. A preliminary review of data collected during a pre-treatment, or calibration period (October 1993 through June 1997), and part of the post-treatment period (July 1997 through November 1998) has identified a varied instream nutrient response to streambank fencing.Concentrations of total nitrogen (N) during low-flow periods were significantly reduced by 20 to 31 percent at treated relative to untreated sites, but the yield of total N during low-flow conditions did not change significantly. Low-flow concentrations and yields of total phosphorus (P) did not change significantly at the outlet of the treatment basin, but data from a tributary site (T-2) in the treatment basin showed a 19- to 79-percent increase in the concentration and yield of total P relative to those at untreated sites. The total-P increase was due to increased concentrations of dissolved P. The processes causing the decrease in the concentration of total N and an increase in the concentration of total P were related to stream discharge, which declined after fencing to about one-third lower than the period-of-record mean. Declines in stream discharge after fence installation were caused by lower than normal precipitation. As concentrations of dissolved oxygen decreased in the stream channel as flows decreased, there was increased potential for instream denitrification and solubilization of P from sediments in the stream channel. Vegetative uptake of nitrate could also have contributed to decreased N concentrations. There were few significant changes in concentrations and yields of nutrients during stormflow except for significant reductions of 16 percent for total-N concentrations and 26 percent for total-P concentrations at site T-2 relative to the site at the outlet of the control basin.Suspended-sediment concentrations in the stream were significantly reduced by fencing. These reductions were partially caused by reduced cow access to the stream and hence reduced potential for the cows to destabilize streambanks through trampling. Development of a vegetative buffer along the stream channel after fence installation also helped to retain soil eroding from upgradient land. Reductions in suspended sediment during low flow ranged from 17 to 26 percent; stormflow reductions in suspended sediment ranged from 21 to 54 percent at treated relative to untreated sites. Suspended-sediment yields, however, were significantly reduced only at site T-2, where low-flow and stormflow yields were reduced by about 25 and 10 percent, respectively, relative to untreated sites.Benthic-macroinvertebrate sampling has identified increased number of taxa in the treatment basin after fence installation. Relative to the control basin, there was about a 30-percent increase in the total number of taxa. This increase was most likely related to improved instream habitat as a result of channel revegetation.

Non-Operational Property Evaluation for the Hanford Site River Corridor - 12409

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

Lowe, John; Aly, Alaa

2012-07-01

The Hanford Site River Corridor consists of the former reactor areas of the 100 Areas and the former industrial (fuel processing) area in the 300 Area. Most of the waste sites are located close to the decommissioned reactors or former industrial facilities along the Columbia River. Most of the surface area of the River Corridor consists of land with little or no subsurface infrastructure or indication of past or present releases of hazardous constituents, and is referred to as non-operational property or non-operational area. Multiple lines of evidence have been developed to assess identified fate and transport mechanisms and tomore » evaluate the potential magnitude and significance of waste site-related contaminants in the non-operational area. Predictive modeling was used for determining the likelihood of locating waste sites and evaluating the distribution of radionuclides in soil based on available soil concentration data and aerial radiological surveys. The results of this evaluation indicated: 1) With the exception of stack emissions, transport pathways associated with waste site contaminants are unlikely to result in dispersion of contaminants in soil away from operational areas, 2) Stack emissions that may have been associated with Hanford Site operations generally emitted short-lived and/or gaseous radionuclides, and (3) the likelihood of detecting elevated radionuclide concentrations or other waste sites in non-operational area soils is very small. The overall conclusions from the NPE evaluation of the River Corridor are: - With the exception of stack emissions to the air, transport pathways associated with waste site contaminants are unlikely to result in dispersion of contaminants in soil away from operational areas. While pathways such as windblown dust, overland transport and biointrusion have the potential for dispersing waste site contaminants, the resulting transport is unlikely to result in substantial contamination in non-operational areas. - Stack emissions that may have been associated with Hanford Site operations generally emitted short-lived and/or gaseous radionuclides; these radionuclides either would have decayed and would be undetectable in soil, or likely would not have deposited onto Hanford Site soils. A small fraction of the total historical emissions consisted of long-lived particulate radionuclides, which could have deposited onto the soil. Soil monitoring studies conducted as part of surveillance and monitoring programs do not indicate a build-up of radionuclide concentrations in soil, which might indicate potential deposition impacts from stack emissions. Aerial radiological surveys of the Hanford Site, while effective in detecting gamma-emitting nuclides, also do not indicate deposition patterns in soil from stack emissions. - The surveillance and monitoring programs also have verified that the limited occurrence of biointrusion observed in the River Corridor has not resulted in a spread of contamination into the non-operational areas. - Monitoring of radionuclides in ambient air conducted as part of the surveillance and monitoring programs generally show a low and declining trend of detected concentrations in air. Monitoring of radionuclides in soil and vegetation correspondingly show declining trends in concentrations, particularly for nuclides with short half lives (Cs-137, Co-60 and Sr-90). - Statistical analysis of the geographical distribution of waste sites based on man -made features and topography describes the likely locations of waste sites in the River Corridor. The results from this analysis reinforce the findings from the Orphan Site Evaluation program, which has systematically identified any remaining waste sites within the River Corridor. - Statistical analysis of the distribution of radionuclide concentrations observable from aerial surveys has confirmed that the likelihood of detecting elevated radionuclide concentrations in non-operational area soils is very small; the occurrences and locations where potentially elevated concentrations may be found are discussed below. In addition, statistical analysis showed that there is a relatively high probability (>50%) that concentrations of Cs-137 higher than background (3.9 Bq/kg or 1.05 pCi/g) are located outside of the operational portion of the 100-BC, 100-K, and 100-N Areas. This observation is based on modeled concentrations in soil derived from aerial radiography data. However, the extent is limited to a few meters from the respective facilities fence lines or known operational activities. Evaluation of the extent of contamination is being conducted as part of the RI process for each decision area. No unanticipated waste sites were identified either from the OSE program or statistical analysis of waste site proximity to known features. Based on the evaluation of these multiple lines of evidence, the likelihood of identifying waste sites or contaminant dispersal from Hanford site operations into non-operational areas can be considered very small. (authors)« less

Fugitive methane assessment with mobile and fence line sensors

EPA Science Inventory

There is no published abstract for this short panel talk. The panel presentation titled “Fugitive methane assessment with mobile and fence line sensors” provides a basic introduction to the topic of next generation sensor technologies for identifying and fixing emiss...

GCM work order status

DOT National Transportation Integrated Search

1996-12-31

The GCM Corridor is one of four "Priority Corridors" throughout the country. These corridors have been selected for special federal transportation funding based on very specific transportation and environmental criteria. The corridor includes the gre...

Can dispersal mode predict corridor effects on plant parasites?

PubMed

Sullivan, Lauren L; Johnson, Brenda L; Brudvig, Lars A; Haddad, Nick M

2011-08-01

Habitat corridors, a common management strategy for increasing connectivity in fragmented landscapes, have experimentally validated positive influences on species movement and diversity. However, long-standing concerns that corridors could negatively impact native species by spreading antagonists, such as disease, remain largely untested. Using a large-scale, replicated experiment, we evaluated whether corridors increase the incidence of plant parasites. We found that corridor impacts varied with parasite dispersal mode. Connectivity provided by corridors increased incidence of biotically dispersed parasites (galls on Solidago odora) but not of abiotically dispersed parasites (foliar fungi on S. odora and three Lespedeza spp.). Both biotically and abiotically dispersed parasites responded to edge effects, but the direction of responses varied across species. Although our results require additional tests for generality to other species and landscapes, they suggest that, when establishing conservation corridors, managers should focus on mitigating two potential negative effects: the indirect effects of narrow corridors in creating edges and direct effects of corridors in enhancing connectivity of biotically dispersed parasites.

Biomechanical investigation of an alternative concept to angular stable plating using conventional fixation hardware.

PubMed

Windolf, Markus; Klos, Kajetan; Wähnert, Dirk; van der Pol, Bas; Radtke, Roman; Schwieger, Karsten; Jakob, Roland P

2010-05-21

Angle-stable locking plates have improved the surgical management of fractures. However, locking implants are costly and removal can be difficult. The aim of this in vitro study was to evaluate the biomechanical performance of a newly proposed crossed-screw concept ("Fence") utilizing conventional (non-locked) implants in comparison to conventional LC-DCP (limited contact dynamic compression plate) and LCP (locking compression plate) stabilization, in a human cadaveric diaphyseal gap model. In eight pairs of human cadaveric femora, one femur per pair was randomly assigned to receive a Fence construct with either elevated or non-elevated plate, while the contralateral femur received either an LCP or LC-DCP instrumentation. Fracture gap motion and fatigue performance under cyclic loading was evaluated successively in axial compression and in torsion. Results were statistically compared in a pairwise setting. The elevated Fence constructs allowed significantly higher gap motion compared to the LCP instrumentations (axial compression: p

2D Nanoporous Fe-N/C Nanosheets as Highly Efficient Non-Platinum Electrocatalysts for Oxygen Reduction Reaction in Zn-Air Battery.

PubMed

Yang, Zheng Kun; Lin, Ling; Xu, An-Wu

2016-11-01

It is an ongoing challenge to fabricate nonprecious oxygen reduction reaction (ORR) catalysts that can be comparable to or exceed the efficiency of platinum. A highly active non-platinum self-supporting Fe-N/C catalyst has been developed through the pyrolysis of a new type of precursor of iron coordination complex, in which 1,4-bis(1H-1,3,7,8-tetraazacyclopenta(1)phenanthren-2-yl)benzene (btcpb) functions as a ligand complexing Fe(II) ions. The optimal catalyst pyrolyzed at 700 °C (Fe-N/C-700) shows the best ORR activity with a half-wave potential (E 1/2 ) of 840 mV versus reversible hydrogen electrode (RHE) in 0.1 m KOH, which is more positive than that of commercial Pt/C (E 1/2 : 835 mV vs RHE). Additionally, the Fe-N/C-700 catalyst also exhibits high ORR activity in 0.1 m HClO 4 with the onset potential and E 1/2 comparable to those of the Pt/C catalyst. Notably, the Fe-N/C-700 catalyst displays superior durability (9.8 mV loss in 0.1 m KOH and 23.6 mV loss in 0.1 m HClO 4 for E 1/2 after 8000 cycles) and better tolerance to methanol than Pt/C. Furthermore, the Fe-N/C-700 catalyst can be used for fabricating the air electrode in Zn-air battery with a specific capacity of 727 mA hg -1 at 5 mA cm -2 and a negligible voltage loss after continuous operation for 110 h. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Alternative Fuels Data Center: West Virginia CNG Corridor Now Open

Science.gov Websites

West Virginia CNG Corridor Now Open to someone by E-mail Share Alternative Fuels Data Center: West Virginia CNG Corridor Now Open on Facebook Tweet about Alternative Fuels Data Center: West Virginia CNG Corridor Now Open on Twitter Bookmark Alternative Fuels Data Center: West Virginia CNG Corridor Now Open on

Response variables for evaluation of the effectiveness of conservation corridors.

PubMed

Gregory, Andrew J; Beier, Paul

2014-06-01

Many studies have evaluated effectiveness of corridors by measuring species presence in and movement through small structural corridors. However, few studies have assessed whether these response variables are adequate for assessing whether the conservation goals of the corridors have been achieved or considered the costs or lag times involved in measuring the response variables. We examined 4 response variables-presence of the focal species in the corridor, interpatch movement via the corridor, gene flow, and patch occupancy--with respect to 3 criteria--relevance to conservation goals, lag time (fewest generations at which a positive response to the corridor might be evident with a particular variable), and the cost of a study when applying a particular variable. The presence variable had the least relevance to conservation goals, no lag time advantage compared with interpatch movement, and only a moderate cost advantage over interpatch movement or gene flow. Movement of individual animals between patches was the most appropriate response variable for a corridor intended to provide seasonal migration, but it was not an appropriate response variable for corridor dwellers, and for passage species it was only moderately relevant to the goals of gene flow, demographic rescue, and recolonization. Response variables related to gene flow provided a good trade-off among cost, relevance to conservation goals, and lag time. Nonetheless, the lag time of 10-20 generations means that evaluation of conservation corridors cannot occur until a few decades after a corridor has been established. Response variables related to occupancy were most relevant to conservation goals, but the lag time and costs to detect corridor effects on occupancy were much greater than the lag time and costs to detect corridor effects on gene flow. © 2014 Society for Conservation Biology.

Complexity Analysis of Traffic in Corridors-in-the-Sky

NASA Technical Reports Server (NTRS)

Xue, Min; Zelinski, Shannon Jean

2010-01-01

The corridors-in-the-sky concept imitates the highway system in ground transportation. The benefit expected from a corridor relies on its capability of handling high density traffic with negligible controller workload, the acceptance of extra fuel or distance, and the complexity reduction in underlying sectors. This work evaluates a selected corridor from these perspectives through simulations. To examine traffic inside the corridor, a corridor traffic simulation tool that can resolve conflicts is developed using C language. Prescribed conflict resolution maneuvers mimic corridor users behaviors and conflict resolution counts measure complexity. Different lane options and operational policies are proposed to examine their impacts on complexity. Fuel consumption is calculated and compared for corridor traffic. On the other hand, to investigate the complexity of non-corridor traffic in underlying sectors, the existing Airspace Concept Evaluation System tool is utilized along with the Automated Airspace Concept tool. The number of conflict resolutions is examined and treated as the complexity measurement. The results show heavy traffic can be managed with low complexity for a historical traffic schedule simulated with appropriate operational policies and lane options. For instance, with 608 flights and peak aircraft count of 100, only 84 actions need to be taken in a 24-hour period to resolve the conflicts for an 8-lane corridor. Compared with the fuel consumptions with great circle trajectories, the simulation of corridor traffic shows that the total extra fuel for corridor flights is 26,373 gallons, or 2.76%, which is 0.38% less than flying filed flight plans. Without taking climb and descent portions of corridor traffic, the complexity of underlying sectors is reduced by 17.71%. However the climb and descent portions will eliminate the reduction and the overall complexity of sectors is actually increased by 9.14%.

Interior, underground corridor going to building 500 from the corridor ...

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

Interior, underground corridor going to building 500 from the corridor connecting buildings 511 and 515. - Fitzsimons General Hospital, Infirmary, Northwest Corner of East Bushnell Avenue & South Page Street, Aurora, Adams County, CO

System architecture efforts in the Gary-Chicago-Milwaukee corridor

DOT National Transportation Integrated Search

1998-01-01

The Gary-Chicago-Milwaukee (GCM) Corridor is one of four Priority Corridors throughout the country. These corridors were selected for special federal transportation funding based on very specific transportation and environmental criteria. One o...

29 CFR 779.321 - Inapplicability of “retail concept” to some types of sales or services of an eligible establishment.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and supplies, and fencing and siding for residential installation. In addition to selling the goods... installation of chain link fences around a home or small business establishment is involved, will normally be...

29 CFR 779.321 - Inapplicability of “retail concept” to some types of sales or services of an eligible establishment.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and supplies, and fencing and siding for residential installation. In addition to selling the goods... installation of chain link fences around a home or small business establishment is involved, will normally be...

29 CFR 779.321 - Inapplicability of “retail concept” to some types of sales or services of an eligible establishment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and supplies, and fencing and siding for residential installation. In addition to selling the goods... installation of chain link fences around a home or small business establishment is involved, will normally be...

Designing, developing and implementing a living snow fence program for New York state.

DOT National Transportation Integrated Search

2015-07-01

Living snow fences (LSF) are a form of passive snow control designed to mitigate blowing and drifting snow problems : on roadways. Blowing and drifting snow can increase the cost of highway maintenance and create hazardous driving : conditions when s...

Historical winter weather assessment for snow fence design using a numerical weather model.

DOT National Transportation Integrated Search

2017-03-30

Noriaki Ohara, Ph.D., Assistant Professor (0000-0002-7829-0779) : Snow fence is an effective hazard mitigation measure for the low visibility and low friction of the road surface under : winter weather condition. Prevailing wind directions and snow p...

75 FR 60102 - South Dakota PrairieWinds Project (DOE/EIS-0418)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-29

... feature 101 wind turbine generators; 6,000 square-foot operations and maintenance building and fence... generation facility that would feature 101 wind turbine generators; 6,000 square-foot operations and... turbine generators, operations and maintenance building and fence perimeter, underground communication...

High-Security Fencing for Rail Right-of-way Applications : Current Use and Best Practices.

DOT National Transportation Integrated Search

2015-10-01

The Volpe Center investigated how high-security fencing is used to prevent right-of-way (ROW) trespassing at several urban transit and commuter rail agencies in the United States. Interviews, operations documentation, and site visits were used to gat...

29 CFR 779.321 - Inapplicability of “retail concept” to some types of sales or services of an eligible establishment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and supplies, and fencing and siding for residential installation. In addition to selling the goods... installation of chain link fences around a home or small business establishment is involved, will normally be...

29 CFR 779.321 - Inapplicability of “retail concept” to some types of sales or services of an eligible establishment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... and supplies, and fencing and siding for residential installation. In addition to selling the goods... installation of chain link fences around a home or small business establishment is involved, will normally be...

Hardwood Fence Posts Give Good Service

Treesearch

B. E. Carpenter; T. P. Bouler

1962-01-01

Very few tree species make naturally durable fence posts. Osage-orange, mulberry, black locust, cypress, and some species of cedar are known for the good service they give. But in no case are their names a guarantee. Only the heartwood of these species possesses adequate durability .

Line spread instrumentation for propagation measurements

NASA Technical Reports Server (NTRS)

Bailey, W. H., Jr.

1980-01-01

A line spread device capable of yielding direct measure of a laser beam's line spread function (LSF) was developed and employed in propagation tests conducted in a wind tunnel to examine optimal acoustical suppression techniques for laser cavities exposed to simulated aircraft aerodynamic environments. Measurements were made on various aerodynamic fences and cavity air injection techniques that effect the LSF of a propagating laser. Using the quiescent tunnel as a control, the relative effect of each technique on laser beam quality was determined. The optical instrument employed enabled the comparison of relative beam intensity for each fence or mass injection. It was found that fence height had little effect on beam quality but fence porosity had a marked effect, i.e., 58% porosity alleviated cavity resonance and degraded the beam the least. Mass injection had little effect on the beam LSF. The use of a direct LSF measuring device proved to be a viable means of determining aerodynamic seeing qualities of flow fields.

Is Ammonium Peroxydisulate Indispensable for Preparation of Aniline-Derived Iron-Nitrogen-Carbon Electrocatalysts?

PubMed

Xie, Nan-Hong; Yan, Xiang-Hui; Xu, Bo-Qing

2016-09-08

Iron and nitrogen co-doped carbon (Fe-N-C) materials are among the most active non-precious metal catalysts that could replace Pt-based electrocatalysts for the oxygen reduction reaction (ORR) in fuel cells and metal-air batteries. The synthesis of the Fe-N-C catalysts often involves the use of aniline as the precursor for both N and C and ammonium peroxydisulfate (APS) as an indispensable oxidative initiator for aniline polymerization. Herein, a detailed structure and catalytic ORR performance comparison of aniline-derived Fe-N-C catalysts synthesized with and without the use of APS is reported. The APS-free preparation, which uses Fe(III) ions as the Fe source as well as the aniline polymerization initiator, results in a simple Fe-N-C catalyst with a high activity for the ORR. We show that APS is not necessary for the preparation and even detrimental to the performance of the catalyst. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

2015 Uranium Mill Tailings Radiation Control Act (UMTRCA) Title ll Annual Report, L-Bar, New Mexico Disposal Site

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

Frazier, William; Johnson, Dick

The L-Bar, New Mexico, Uranium Mill Tailings Radiation Control Act (UMTRCA) Title II Disposal Site was inspected on August 18, 2015. The tailings impoundment was in excellent condition. Erosion and vegetation measurements to monitor the condition of the impoundment cover indicated that no erosion is occurring, and perennial vegetation foliar cover at the measurement plots increased substantially compared to previous years due to above-average precipitation for the year. A short segment of the perimeter fence near the site entrance was realigned in spring 2015 because a gully was undermining the fence corner. Loose fence strands at another location were repairedmore » during the inspection, and a section of fence needs to be realigned to avoid areas affected by deep gullies and sediment deposition. Inspectors identified no other maintenance needs or cause for a follow-up inspection. Groundwater monitoring is required every 3 years. The next monitoring event will be in 2016.« less

Wind-Tunnel Investigation at Low Speed of the Effects of Chordwise Wing Fences and Horizontal-Tail Position on the Static Longitudinal Stability Characteristics of an Airplane Model with a 35 Degree Sweptback Wing

NASA Technical Reports Server (NTRS)

Queijo, M J; Jaquet, Byron M; Wolhart, Walter D

1954-01-01

Low-speed tests of a model with a wing swept back 35 degrees at the 0.33-chord line and a horizontal tail located well above the extended wing-chord plane indicated static longitudinal instability at moderate angles of attack for all configurations tested. An investigation therefore was made to determine whether the longitudinal stability could be improved by the use of chordwise wing fences, by lowering the horizontal tail, or by a combination of both. The results of the investigation showed that the longitudinal stability characteristics of the model with slats retracted could be improved at moderate angles of attack by placing chordwise wing fences at a spanwise station of about 73 percent of the wing semispan from the plane of symmetry provided the nose of the fence extended slightly beyond or around the wing leading edge.

Remote sensing impact on corridor selection and placement

NASA Technical Reports Server (NTRS)

Thomson, F. J.; Sellman, A. N.

1975-01-01

Computer-aided corridor selection techniques, utilizing digitized data bases of socio-economic, census, and cadastral data, and developed for highway corridor routing are considered. Land resource data generated from various remote sensing data sources were successfully merged with the ancillary data files of a corridor selection model and prototype highway corridors were designed using the combined data set. Remote sensing derived information considered useful for highway corridor location, special considerations in geometric correction of remote sensing data to facilitate merging it with ancillary data files, and special interface requirements are briefly discussed.

Potential negative ecological effects of corridors.

PubMed

Haddad, Nick M; Brudvig, Lars A; Damschen, Ellen I; Evans, Daniel M; Johnson, Brenda L; Levey, Douglas J; Orrock, John L; Resasco, Julian; Sullivan, Lauren L; Tewksbury, Josh J; Wagner, Stephanie A; Weldon, Aimee J

2014-10-01

Despite many studies showing that landscape corridors increase dispersal and species richness for disparate taxa, concerns persist that corridors can have unintended negative effects. In particular, some of the same mechanisms that underlie positive effects of corridors on species of conservation interest may also increase the spread and impact of antagonistic species (e.g., predators and pathogens), foster negative effects of edges, increase invasion by exotic species, increase the spread of unwanted disturbances such as fire, or increase population synchrony and thus reduce persistence. We conducted a literature review and meta-analysis to evaluate the prevalence of each of these negative effects. We found no evidence that corridors increase unwanted disturbance or non-native species invasion; however, these have not been well-studied concerns (1 and 6 studies, respectively). Other effects of corridors were more often studied and yielded inconsistent results; mean effect sizes were indistinguishable from zero. The effect of edges on abundances of target species was as likely to be positive as negative. Corridors were as likely to have no effect on antagonists or population synchrony as they were to increase those negative effects. We found 3 deficiencies in the literature. First, despite studies on how corridors affect predators, there are few studies of related consequences for prey population size and persistence. Second, properly designed studies of negative corridor effects are needed in natural corridors at scales larger than those achievable in experimental systems. Third, studies are needed to test more targeted hypotheses about when corridor-mediated effects on invasive species or disturbance may be negative for species of management concern. Overall, we found no overarching support for concerns that construction and maintenance of habitat corridors may result in unintended negative consequences. Negative edge effects may be mitigated by widening corridors or softening edges between corridors and the matrix. Other negative effects are relatively small and manageable compared with the large positive effects of facilitating dispersal and increasing diversity of native species. © 2014 Society for Conservation Biology.

Corridors promote fire via connectivity and edge effects.

PubMed

Brudvig, Lars A; Wagner, Stephanie A; Damschen, Ellen I

2012-04-01

Landscape corridors, strips of habitat that connect otherwise isolated habitat patches, are commonly employed during management of fragmented landscapes. To date, most reported effects of corridors have been positive; however, there are long-standing concerns that corridors may have unintended consequences. Here, we address concerns over whether corridors promote propagation of disturbances such as fire. We collected data during prescribed fires in the world's largest and best replicated corridor experiment (Savannah River Site, South Carolina, USA), six -50-ha landscapes of open (shrubby/herbaceous) habitat within a pine plantation matrix, to test several mechanisms for how corridors might influence fire. Corridors altered patterns of fire temperature through a direct connectivity effect and an indirect edge effect. The connectivity effect was independent of fuel levels and was consistent with a hypothesized wind-driven "bellows effect." Edges, a consequence of corridor implementation, elevated leaf litter (fuel) input from matrix pine trees, which in turn increased fire temperatures. We found no evidence for corridors or edges impacting patterns of fire spread: plots across all landscape positions burned with similar probability. Impacts of edges and connectivity on fire temperature led to changes in vegetation: hotter-burning plots supported higher bunch grass cover during the field season after burning, suggesting implications for woody/herbaceous species coexistence. To our knowledge, this represents the first experimental evidence that corridors can modify landscape-scale patterns of fire intensity. Corridor impacts on fire should be carefully considered during landscape management, both in the context of how corridors connect or break distributions of fuels and the desired role of fire as a disturbance, which may range from a management tool to an agent to be suppressed. In our focal ecosystem, longleaf pine woodland, corridors might provide a previously unrecognized benefit during prescribed burning activities, by promoting fire intensity, which may assist in promoting plant biodiversity.

Phenotypic sex ratios of Atriplex canescens shrubs in relation to cattle browsing

Treesearch

Andres F. Cibils; David M. Swift; Richard H. Hart

2001-01-01

Previous studies conducted at our research site on the shortgrass steppe in Colorado showed that phenotypic sex ratios of tetraploid fourwing saltbush (Atriplex canescens Pursh [Nutt]) shrubs were less female biased in grazed pastures than in adjacent exclosures. The potential effects of cattle browsing on shrub sex ratios were studied both in the field and in a...

Long-term response of the mamane forest to feral herbivore management on Mauna Kea, Hawaii

Treesearch

E. Reddy; D. H. Van Vuren; P. G. Scowcroft; J. B. Kauffman; L. Perry

2012-01-01

Seven exclosure sites located on Mauna Kea, Hawaii and established in the 1960s and 70s were sampled to characterize long-term response of the mamane (Sophora chrysophylla) forest to protection from feral sheep grazing, and to assess impacts of non-native plant species and recurrent sheep presence on forest recovery. The forest provides essential...

The Hill plots: A rare long-term vegetation study (P-53)

Treesearch

Jonathan D. Bakker; Margaret M. Moore; Daniel C. Laughlin

2008-01-01

One legacy of the Fort Valley Experimental Forest is the number and quality of long-term studies associated with it. One such study is the "Hill plots," which began in 1912 and is still being actively studied. Livestock exclosures were built at five sites to examine vegetation recovery when protected from livestock grazing. Sites span a range of soil types...

The Hill plots: A rare long-term vegetation study

Treesearch

Jonathan D. Bakker; Margaret M. Moore; Daniel C. Laughlin

2008-01-01

One legacy of the Fort Valley Experimental Forest is the number and quality of long-term studies associated with it. One such study is the "Hill plots," which began in 1912 and is still being actively studied. Livestock exclosures were built at five sites to examine vegetation recovery when protected from livestock grazing. Sites span a range of soil types...

Ungulate exclusion, conifer thinning and mule deer forage in northeastern New Mexico

USGS Publications Warehouse

Kramer, David W.; Sorensen, Grant E.; Taylor, Chase A.; Cox, Robert D.; Gipson, Philip S.; Cain, James W.

2015-01-01

The southwestern United States has experienced expansion of conifer species (Juniperus spp. and Pinus ponderosa) into areas of semi-arid grassland over the past century. The expansion of conifers can limit palatable forage and reduce grass and forb communities. Conifer species are sometimes thinned through hydraulic mulching or selective cutting. We assessed the effects of these treatments on mule deer (Odocoileus hemionus) habitat in northeastern New Mexico to determine if conifer thinning improved cover of preferred forage species for mule deer in areas with and without ungulates. We measured plant cover and occurrence of preferred forage species in the summers of 2011 and 2012. An ongoing regional drought probably reduced vegetation response, with preferred forage species and herbaceous cover responding to conifer thinning or ungulate exclusion immediately following treatment, but not the following year. In 2011, areas that received thinning treatments had a higher abundance of preferred forage when compared to sites with no treatment. Grass coverage exhibited an immediate response in 2011, with ungulate exclosures containing 8% more coverage than areas without exclosures. The results suggest that conifer thinning and ungulate exclusion may elicit a positive response, however in the presence of drought; the positive effects are only short-term.

Effects of integrated watershed management on livestock water productivity in water scarce areas in Ethiopia

NASA Astrophysics Data System (ADS)

Descheemaeker, Katrien; Mapedza, Everisto; Amede, Tilahun; Ayalneh, Wagnew

In the water scarce Lenche Dima watershed in the northern Ethiopian highlands community based integrated watershed management was implemented to fight land degradation, raise agricultural productivity and improve farmers’ livelihoods. The effects of two interventions, namely exclosures and water harvesting structures, were assessed based on data from farmers’ interviews, measurements of feed biomass production, and estimates of energy production and requirements. Water used for livestock feed production was obtained through simple soil water balance modelling. By protecting 40% of the rangelands, the water productivity of the feed increased by about 20%. This indicated that exclosure establishment could lead to similar improvements in livestock water productivity (LWP, defined as the ratio of livestock benefits over the water used in producing these). Water harvesting structures ensured year-round water availability in the homestead, which resulted in less energy used for walking to drinking points. A considerable amount of energy was thus saved, which could be used for livestock production and improved animal health without additional water use. Besides restoring regulating and supporting ecosystem services, both interventions led to a more efficient use of the scarce water resources for biomass and livestock production.

Combining near infrared spectra of feces and geostatistics to generate forage nutritional quality maps across landscapes

NASA Astrophysics Data System (ADS)

Jean, Pierre-Olivier; Bradley, Robert; Tremblay, Jean-Pierre

2015-04-01

An important asset for the management of wild ungulates is the ability to recognize the spatial distribution of forage quality across heterogeneous landscapes. To do so typically requires knowledge of which plant species are eaten, in what abundance they are eaten, and what their nutritional quality might be. Acquiring such data may be, however, difficult and time consuming. Here, we are proposing a rapid and cost-effective forage quality monitoring tool that combines near infrared (NIR) spectra of fecal samples and easily obtained data on plant community composition. Our approach rests on the premise that NIR spectra of fecal samples collected within low population density exclosures reflect the optimal forage quality of a given landscape. Forage quality can thus be based on the Mahalanobis distance of fecal spectral scans across the landscape relative to fecal spectral scans inside exclosures (referred to as DISTEX). The Gi* spatial autocorrelation statistic can then be applied among neighbouring DISTEX values to detect and map 'hot-spots' and 'cold-spots' of nutritional quality over the landscape. We tested our approach in a heterogeneous boreal landscape on Anticosti Island (Qu

Non-overlapping distributions of feral sheep (Ovis aries) and Stout Iguanas (Cyclura pinguis) on Guana Island, British Virgin Islands

USGS Publications Warehouse

Skipper, Ben R.; Grisham, Blake A.; Kalyvaki, Maria; McGaughey, Kathleen; Mougey, Krista; Navarrete, Laura; Rondeau, Renée; Boal, Clint W.; Perry, Gad

2013-01-01

Stout Iguanas (Cyclura pinguis) remain one of the most critically endangered reptiles in the world. Factors contributing to that status include habitat loss, predation by introduced species, and competition with introduced herbivores. On Guana Island, British Virgin Islands, the presence of feral sheep (Ovis aries) has been a hypothesized detriment to iguanas. Using motion sensitive cameras, we documented the distribution of feral sheep on Guana Island in 2010. We also quantified the impact of feral sheep on ground vegetation by comparing plant abundance at longterm sheep exclosures and areas where sheep were absent to areas where sheep were present. Finally, we compared sheep distribution to iguana distribution on the island. The co-occurrence of sheep and Stout Iguanas was less than expected, indicating possible competition. Although we detected no difference in vegetative cover between areas where sheep were present and absent, the long-term exclosures showed that the exclusion of sheep allowed the abundance of many plant species to increase. Our data support the hypothesis that feral sheep are altering the abundance of ground-level vegetation and limiting iguana distribution on the island.

RISK CORRIDORS AND REINSURANCE IN HEALTH INSURANCE MARKETPLACES

PubMed Central

LAYTON, TIMOTHY J.; MCGUIRE, THOMAS G.; SINAIKO, ANNA D.

2016-01-01

Health Insurance Marketplaces established by the Affordable Care Act implement reinsurance and risk corridors. Reinsurance limits insurer costs associated with specific individuals, while risk corridors protect against aggregate losses. Both tighten the insurer’s distribution of expected costs. This paper compares the economic costs and consequences of reinsurance and risk corridors. We simulate the insurer’s cost distribution under reinsurance and risk corridors using data for a group of individuals likely to enroll in Marketplace plans from the Medical Expenditure Panel Survey. We compare reinsurance and risk corridors in terms of risk reduction and incentives for cost containment. We find that reinsurance and one-sided risk corridors achieve comparable levels of risk reduction for a given level of incentives. We also find that the policies being implemented in the Marketplaces (a mix of reinsurance and two-sided risk corridor policies) substantially limit insurer risk but perform similarly to a simpler stand-alone reinsurance policy. PMID:26973861

Estimating the Environmental Costs of Africa's Massive "Development Corridors".

PubMed

Laurance, William F; Sloan, Sean; Weng, Lingfei; Sayer, Jeffrey A

2015-12-21

In sub-Saharan Africa, dozens of major "development corridors" have been proposed or are being created to increase agricultural production [1-4], mineral exports [5-7], and economic integration. The corridors involve large-scale expansion of infrastructure such as roads, railroads, pipelines, and port facilities and will open up extensive areas of land to new environmental pressures [1, 4, 8]. We assessed the potential environmental impacts of 33 planned or existing corridors that, if completed, would total over 53,000 km in length and crisscross much of the African continent. We mapped each corridor and estimated human occupancy (using the distribution of persistent night-lights) and environmental values (endangered and endemic vertebrates, plant diversity, critical habitats, carbon storage, and climate-regulation services) inside a 50-km-wide band overlaid onto each corridor. We also assessed the potential for each corridor to facilitate increases in agricultural production. The corridors varied considerably in their environmental values, and many were only sparsely populated. Because of marginal soils or climates, some corridors appear to have only modest agricultural potential. Collectively, the corridors would bisect over 400 existing protected areas and could degrade a further ~1,800 by promoting habitat disruption near or inside the reserves. We conclude that many of the development corridors will promote serious and largely irreversible environmental changes and should proceed only if rigorous mitigation and protection measures can be employed. Some planned corridors with high environmental values and limited agricultural benefits should possibly be cancelled altogether. VIDEO ABSTRACT. Copyright © 2015 Elsevier Ltd. All rights reserved.

Study on the oasis corridor landscape in the arid regions based on RS and GIS methods--application of Jinta Oasis, China.

PubMed

Ma, Ming-guo; Wang, Xue-mei; Cheng, Guo-dong

2003-03-01

The study on the oasis corridor landsape is a new hotspot in the ecological environment research in the arid regions. In oasis, main corridor landscape types include river, ditch, shelterbelt and road. This paper introduces the basic ecological effects of the corridor landscape on the transporting mass and energy and obstructing desert landscape expansion and incursion. Using Geographic Information System (GIS), we have researched the corridor distribution and its spatial relationship with other landscape types in the Jinta Oasis. Based on the dynamically monitoring on the landscape pattern change of the Jinta Oasis during the latter 10 years by using Remote Sensing (RS) and GIS, the driving functions of the corridors on this change have been analyzed in detail. The analysis results showed that all kinds of corridors' characteristics can be quantified by the indexes such as length and width, ratio of perimeter and area, density and non-heterogeneity. The total corridor length of Jinta Oasis is 1838.5 km and its density is 2.1 km/km2. The corridor density of the irrigation land, forest and resident area is maximal, which shows that affection degree of the oasis corridors on them is the most. The improvement of the corridors quality is one of the important driving factors on the irrigation land and so on. The organic combination of the RS and GIS technologies and landscape research methods would be an effective means for the corridor landscape research on arid region oasis.

52. 2E corridor, from intersection of 2F corridor, second floor, ...

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

52. 2E corridor, from intersection of 2F corridor, second floor, building 500, looking east - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

Corridor Planning And Feasibility Analysis Corridor, Master Plan

DOT National Transportation Integrated Search

1996-04-01

THE I-70 RURAL IVHS CORRIDOR MASTER PLAN IS THE GUIDANCE DOCUMENT FOR DEPLOYMENT OF THE INTELLIGENT TRANSPORTATION SYSTEM (ITS) FOR THE INTERSTATE-70 CORRIDOR FROM DENVER TO GLENWOOD SPRINGS, COLORADO. AS A WORKING DOCUMENT, THE PLAN RECOMMENDS STRAT...

Stream-crossing structure for deer fence

Treesearch

Robert M. Blair; James A. Hays; Louis Brunett

1963-01-01

Stream crossings are the most vulnerable points in a deer-proof fence. When an inadequately constructed crossing washes out, enclosed deer may escape and unwanted animals enter. Structures of the type described here have withstood 2 years of frequent, severe flooding in the pine-hardwood hills of central Louisiana.

Facility fence-line monitoring using passive samplers

EPA Science Inventory

In 2009, the U.S. EPA executed a year-long field study at a refinery in Corpus Christi, Texas, to evaluate the use of passive diffusive sampling technology for assessing time-averaged benzene concentrations at the facility fence line. The study utilized 14-day time-integrated Car...

Identifying On-Orbit Test Targets for Space Fence Operational Testing

NASA Astrophysics Data System (ADS)

Pechkis, D.; Pacheco, N.; Botting, T.

2014-09-01

Space Fence will be an integrated system of two ground-based, S-band (2 to 4 GHz) phased-array radars located in Kwajalein and perhaps Western Australia [1]. Space Fence will cooperate with other Space Surveillance Network sensors to provide space object tracking and radar characterization data to support U.S. Strategic Command space object catalog maintenance and other space situational awareness needs. We present a rigorous statistical test design intended to test Space Fence to the letter of the program requirements as well as to characterize the system performance across the entire operational envelope. The design uses altitude, size, and inclination as independent factors in statistical tests of dependent variables (e.g., observation accuracy) linked to requirements. The analysis derives the type and number of necessary test targets. Comparing the resulting sample sizes with the number of currently known targets, we identify those areas where modelling and simulation methods are needed. Assuming hypothetical Kwajalein radar coverage and a conservative number of radar passes per object per day, we conclude that tests involving real-world space objects should take no more than 25 days to evaluate all operational requirements; almost 60 percent of the requirements can be tested in a single day and nearly 90 percent can be tested in one week or less. Reference: [1] L. Haines and P. Phu, Space Fence PDR Concept Development Phase, 2011 AMOS Conference Technical Papers.

I-10 national freight corridor study : phase II report, corridor ITS architecture.

DOT National Transportation Integrated Search

2007-01-01

The Interstate 10 National Freight Corridor extends : across the eight states that form the southern boundary : of the contiguous 48 states. From west to east, the : corridor crosses parts of California, Arizona, New : Mexico, Texas, Louisiana, Missi...

77 FR 3326 - Northeast Corridor Safety Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-23

.... 3] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of Northeast Corridor Safety Committee Meeting. SUMMARY: FRA announced the first meeting of the Northeast Corridor Safety Committee, a Federal...

76 FR 34139 - Northeast Corridor Safety Committee; Meeting Postponement

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-10

.... 2] Northeast Corridor Safety Committee; Meeting Postponement AGENCY: Federal Railroad Administration... announced the first meeting of the Northeast Corridor Safety Committee, a Federal Advisory Committee... future date. DATES: The meeting of the Northeast Corridor Safety Committee scheduled to commence on...

76 FR 32391 - Northeast Corridor Safety Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-06

.... 1] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of the Northeast Corridor Safety Committee Meeting. SUMMARY: FRA announces the first meeting of the Northeast Corridor Safety Committee, a...

Integrated corridor management analysis, modeling, and simulation results for the test corridor.

DOT National Transportation Integrated Search

2008-06-01

This report documents the Integrated Corridor Management (ICM) Analysis Modeling and Simulation (AMS) tools and strategies used on a Test Corridor, presents results and lessons-learned, and documents the relative capability of AMS to support benefit-...

Corridors Increase Plant Species Richness at Large Scales

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

Damschen, Ellen I.; Haddad, Nick M.; Orrock,John L.

2006-09-01

Habitat fragmentation is one of the largest threats to biodiversity. Landscape corridors, which are hypothesized to reduce the negative consequences of fragmentation, have become common features of ecological management plans worldwide. Despite their popularity, there is little evidence documenting the effectiveness of corridors in preserving biodiversity at large scales. Using a large-scale replicated experiment, we showed that habitat patches connected by corridors retain more native plant species than do isolated patches, that this difference increases over time, and that corridors do not promote invasion by exotic species. Our results support the use of corridors in biodiversity conservation.

Corridors increase plant species richness at large scales.

PubMed

Damschen, Ellen I; Haddad, Nick M; Orrock, John L; Tewksbury, Joshua J; Levey, Douglas J

2006-09-01

Habitat fragmentation is one of the largest threats to biodiversity. Landscape corridors, which are hypothesized to reduce the negative consequences of fragmentation, have become common features of ecological management plans worldwide. Despite their popularity, there is little evidence documenting the effectiveness of corridors in preserving biodiversity at large scales. Using a large-scale replicated experiment, we showed that habitat patches connected by corridors retain more native plant species than do isolated patches, that this difference increases over time, and that corridors do not promote invasion by exotic species. Our results support the use of corridors in biodiversity conservation.

Observations of particulates within the North Atlantic Flight Corridor: POLINAT 2, September-October 1997

NASA Astrophysics Data System (ADS)

Paladino, J. D.; Hagen, D. E.; Whitefield, P. D.; Hopkins, A. R.; Schmid, O.; Wilson, M. R.; Schlager, H.; Schulte, P.

2000-02-01

This paper discusses participate concentration and size distribution data gathered using the University of Missouri-Rolla Mobile Aerosol Sampling System (UMR-MASS), and used to investigate the southern extent of the eastern end of the North Atlantic Flight Corridor (NAFC) during project Pollution From Aircraft Emissions in the North Atlantic Flight Corridor/Subsonic Assessment (SASS) Ozone and Nitrogen Oxide Experiment (POLINAT 2/SONEX) from September 19 to October 23, 1997. The analysis presented in this paper focuses on "the corridor effect," or enhancement of pollutants by jet aircraft combustion events. To investigate the phenomena, both vertical and horizontal profiles of the corridor, and regions immediately adjacent to the corridor, were performed. The profiles showed a time-dependent enhancement of particulates within the corridor, and a nonvolatile (with respect to thermal volatilization at 300°C) aerosol enhancement at corridor altitudes by a factor of 3.6. The southern extent of the North Atlantic Flight Corridor was established from a four flight average of the particulate data and yielded a boundary near 42.5°N during the study period. A size distribution analysis of the nonvolatile particulates revealed an enhancement in the <40 nm particulates for size distributions recorded within the flight corridor.

Oil pipeline corridor through an intact forest alters ground beetle (Coleoptera: Carabidae) assemblages in southeastern Ohio.

PubMed

Silverman, Bareena; Horn, David J; Purrington, Foster F; Gandhi, Kamal J K

2008-06-01

Litter-dwelling ground beetle (Coleoptera: Carabidae) assemblages were monitored 1 yr after the construction of a corridor for installation of an oil pipeline along a xeric ridge-top forest in southeastern Ohio. After the creation of the corridor, three distinct habitats were evident in these sites: open corridor, ecotone areas around the corridor, and undisturbed forest interior. Carabidae were collected using directional pitfall traps that were placed parallel and perpendicular to the corridor in each of the three habitats. Results indicate that more carabids were present in the ecotone than in the other two habitats. Carabid diversity as estimated by rarefaction was highest in the corridor followed by ecotone and forest interior. Generalist and forest specialists such as Synuchus impunctatus (Say), Carabus goryi Dejean, and Pterostichus trinarius (Casey) were present in greater numbers in the forest interior and ecotone assemblages. In contrast, open-habitat specialists such as Harpalus pensylvanicus (DeGeer) and Selenophorus opalinus (LeConte) were present in greater numbers in the corridor assemblages. Carabid assemblages of the corridor were distinct from those of the ecotone and forest interior, whereas the latter two habitats had very similar assemblages. The successional pathway of the corridor carabid assemblage will therefore be likely different from that of the forest interior and ecotone. Overall, results indicate that construction of the oil pipeline corridor had significant short-term effects on the carabid numbers, diversity, and species composition because of ensuing habitat changes and fragmentation of the forest.

Fence Posts and Rails

ERIC Educational Resources Information Center

Turton, Roger

2016-01-01

"Mathematical Lens" uses photographs as a springboard for mathematical inquiry and appears in every issue of "Mathematics Teacher." Recently while dismantling an old wooden post-and-rail fence, Roger Turton noticed something very interesting when he piled up the posts and rails together in the shape of a prism. The total number…

Silt fences: An economical technique for measuring hillslope soil erosion

Treesearch

Peter R. Robichaud; Robert E. Brown

2002-01-01

Measuring hillslope erosion has historically been a costly, time-consuming practice. An easy to install low-cost technique using silt fences (geotextile fabric) and tipping bucket rain gauges to measure onsite hillslope erosion was developed and tested. Equipment requirements, installation procedures, statistical design, and analysis methods for measuring hillslope...

4. Inside perimeter fence, view towards east and launch closure, ...

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

4. Inside perimeter fence, view towards east and launch closure, sensor EMP antenna left center - Ellsworth Air Force Base, Delta Flight, Launch Facility D-6, 4 miles north of Badlands National Park Headquarters, 4.5 miles east of Jackson County line on county road, Interior, Jackson County, SD

123. ARAI Substation (ARA726) plan, elevation, security fence details, and ...

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

123. ARA-I Substation (ARA-726) plan, elevation, security fence details, and sections. Norman Engineering Company 961-area/SF-726-E-1. Date: January 1959. Ineel index code no. 068-0726-10-613-102778. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

14 CFR 151.95 - Fences; distance markers; navigational and landing aids; and offsite work.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Fences; distance markers; navigational and landing aids; and offsite work. 151.95 Section 151.95 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming...

Effects of streambank fencing of pasture land on benthic macroinvertebrates and the quality of surface water and shallow ground water in the Big Spring Run basin of Mill Creek watershed, Lancaster County, Pennsylvania, 1993-2001

USGS Publications Warehouse

Galeone, Daniel G.; Brightbill, Robin A.; Low, Dennis J.; O'Brien, David L.

2006-01-01

Streambank fencing along stream channels in pastured areas and the exclusion of pasture animals from the channel are best-management practices designed to reduce nutrient and suspended-sediment yields from drainage basins. Establishment of vegetation in the fenced area helps to stabilize streambanks and provides better habitat for wildlife in and near the stream. This study documented the effectiveness of a 5- to 12-foot-wide buffer strip on the quality of surface water and near-stream ground water in a 1.42-mi2 treatment basin in Lancaster County, Pa. Two miles of stream were fenced in the basin in 1997 following a 3- to 4-year pre-treatment period of monitoring surface- and ground-water variables in the treatment and control basins. Changes in surface- and ground-water quality were monitored for about 4 years after fence installation. To alleviate problems in result interpretation associated with climatic and hydrologic variation over the study period, a nested experimental design including paired-basin and upstream/downstream components was used to study the effects of fencing on surface-water quality and benthic-macroinvertebrate communities. Five surface-water sites, one at the outlet of a 1.77-mi2 control basin (C-1), two sites in the treatment basin (T-3 and T-4) that were above any fence installation, and two sites (one at an upstream tributary site (T-2) and one at the outlet (T-1)) that were treated, were sampled intensively. Low-flow samples were collected at each site (approximately 25-30 per year at each site), and stormflow was sampled with automatic samplers at all sites except T-3. For each site where stormflow was sampled, from 35 to 60 percent of the storm events were sampled over the entire study period. Surface-water sites were sampled for analyses of nutrients, suspended sediment, and fecal streptococcus (only low-flow samples), with field parameters (only low-flow samples) measured during sample collection. Benthic-macroinvertebrate samples were collected in May and September of each year; samples were collected at the outlet of the control and treatment basins and at three upstream sites, two in the treatment basin and one in the control basin. For each benthic-macroinvertebrate sample: Stream riffles and pools were sampled using the kick-net method; habitat was characterized using Rapid Bioassessment Protocols (RBP); water-quality samples were collected for nutrients and suspended sediment; stream field parameters were measured; and multiple biological metrics were calculated. The experimental design to study the effects of fencing on the quality of near-stream shallow ground water involved a nested well approach. Two well nests were in the treatment basin, one each at surface-water sites T-1 and T-2. Within each well nest, the data from one deep well and three shallow wells (no greater than 12 ft deep) were used for regional characterization of ground-water quality. At each site, two of the shallow wells were inside the eventual fence (treated wells); the other shallow well was outside the eventual fence (control well). The wells were sampled monthly, primarily during periods with little to no recharge, for laboratory analysis of nutrients and fecal streptococcus; field parameters of water quality also were measured.

Integrated corridor management initiative : demonstration phase evaluation – Dallas corridor performance analysis test plan.

DOT National Transportation Integrated Search

2012-08-01

This report presents the test plan for conducting the Corridor Performance Analysis for the United States Department of Transportation (U.S. DOT) evaluation of the Dallas U.S. 75 Integrated Corridor Management (ICM) Initiative Demonstration. The ICM ...

Integrated corridor management initiative : demonstration phase evaluation – San Diego corridor performance analysis test plan.

DOT National Transportation Integrated Search

2012-08-01

This report presents the test plan for conducting the Corridor Performance Analysis for the United States Department of Transportation (U.S. DOT) evaluation of the San Diego Integrated Corridor Management (ICM) Initiative Demonstration. The ICM proje...

20. Readiness Crew Building interior, upper level corridor. This corridor ...

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

20. Readiness Crew Building interior, upper level corridor. This corridor runs from northwest to southeast. Photograph taken at the northwest end looking southeast. Lyon - Whiteman Air Force Base, Bomber Alert Facility S-6, 1300 Alert Road, Knob Noster, Johnson County, MO

Research notes : are safety corridors really safe? Evaluation of the corridor safety improvement program.

DOT National Transportation Integrated Search

1998-08-26

High accident frequencies on Oregons highway corridors are of concern to the Oregon Department of Transportation (ODOT). : ODOT adopted the Corridor Safety Improvement Program as part of an overall program of safety improvements using federal and ...

FRACOR-software toolbox for deterministic mapping of fracture corridors in oil fields on AutoCAD platform

NASA Astrophysics Data System (ADS)

Ozkaya, Sait I.

2018-03-01

Fracture corridors are interconnected large fractures in a narrow sub vertical tabular array, which usually traverse entire reservoir vertically and extended for several hundreds of meters laterally. Fracture corridors with their huge conductivities constitute an important element of many fractured reservoirs. Unlike small diffuse fractures, actual fracture corridors must be mapped deterministically for simulation or field development purposes. Fracture corridors can be identified and quantified definitely with borehole image logs and well testing. However, there are rarely sufficient image logs or well tests, and it is necessary to utilize various fracture corridor indicators with varying degrees of reliability. Integration of data from many different sources, in turn, requires a platform with powerful editing and layering capability. Available commercial reservoir characterization software packages, with layering and editing capabilities, can be cost intensive. CAD packages are far more affordable and may easily acquire the versatility and power of commercial software packages with addition of a small software toolbox. The objective of this communication is to present FRACOR, a software toolbox which enables deterministic 2D fracture corridor mapping and modeling on AutoCAD platform. The FRACOR toolbox is written in AutoLISPand contains several independent routines to import and integrate available fracture corridor data from an oil field, and export results as text files. The resulting fracture corridor maps consists mainly of fracture corridors with different confidence levels from combination of static and dynamic data and exclusion zones where no fracture corridor can exist. The exported text file of fracture corridors from FRACOR can be imported into an upscaling programs to generate fracture grid for dual porosity simulation or used for field development and well planning.

Effects of weighting schemes on the identification of wildlife corridors generated with least-cost methods.

PubMed

Parks, Sean A; McKelvey, Kevin S; Schwartz, Michael K

2013-02-01

The importance of movement corridors for maintaining connectivity within metapopulations of wild animals is a cornerstone of conservation. One common approach for determining corridor locations is least-cost corridor (LCC) modeling, which uses algorithms within a geographic information system to search for routes with the lowest cumulative resistance between target locations on a landscape. However, the presentation of multiple LCCs that connect multiple locations generally assumes all corridors contribute equally to connectivity, regardless of the likelihood that animals will use them. Thus, LCCs may overemphasize seldom-used longer routes and underemphasize more frequently used shorter routes. We hypothesize that, depending on conservation objectives and available biological information, weighting individual corridors on the basis of species-specific movement, dispersal, or gene flow data may better identify effective corridors. We tested whether locations of key connectivity areas, defined as the highest 75th and 90th percentile cumulative weighted value of approximately 155,000 corridors, shift under different weighting scenarios. In addition, we quantified the amount and location of private land that intersect key connectivity areas under each weighting scheme. Some areas that appeared well connected when analyzed with unweighted corridors exhibited much less connectivity compared with weighting schemes that discount corridors with large effective distances. Furthermore, the amount and location of key connectivity areas that intersected private land varied among weighting schemes. We believe biological assumptions and conservation objectives should be explicitly incorporated to weight corridors when assessing landscape connectivity. These results are highly relevant to conservation planning because on the basis of recent interest by government agencies and nongovernmental organizations in maintaining and enhancing wildlife corridors, connectivity will likely be an important criterion for prioritization of land purchases and swaps. ©2012 Society for Conservation Biology.

Large-Scale Habitat Corridors for Biodiversity Conservation: A Forest Corridor in Madagascar

PubMed Central

Ramiadantsoa, Tanjona; Ovaskainen, Otso; Rybicki, Joel; Hanski, Ilkka

2015-01-01

In biodiversity conservation, habitat corridors are assumed to increase landscape-level connectivity and to enhance the viability of otherwise isolated populations. While the role of corridors is supported by empirical evidence, studies have typically been conducted at small spatial scales. Here, we assess the quality and the functionality of a large 95-km long forest corridor connecting two large national parks (416 and 311 km2) in the southeastern escarpment of Madagascar. We analyze the occurrence of 300 species in 5 taxonomic groups in the parks and in the corridor, and combine high-resolution forest cover data with a simulation model to examine various scenarios of corridor destruction. At present, the corridor contains essentially the same communities as the national parks, reflecting its breadth which on average matches that of the parks. In the simulation model, we consider three types of dispersers: passive dispersers, which settle randomly around the source population; active dispersers, which settle only in favorable habitat; and gap-avoiding active dispersers, which avoid dispersing across non-habitat. Our results suggest that long-distance passive dispersers are most sensitive to ongoing degradation of the corridor, because increasing numbers of propagules are lost outside the forest habitat. For a wide range of dispersal parameters, the national parks are large enough to sustain stable populations until the corridor becomes severely broken, which will happen around 2065 if the current rate of forest loss continues. A significant decrease in gene flow along the corridor is expected after 2040, and this will exacerbate the adverse consequences of isolation. Our results demonstrate that simulation studies assessing the role of habitat corridors should pay close attention to the mode of dispersal and the effects of regional stochasticity. PMID:26200351

Evaluating Landscape Options for Corridor Restoration between Giant Panda Reserves

PubMed Central

Wang, Fang; McShea, William J.; Wang, Dajun; Li, Sheng; Zhao, Qing; Wang, Hao; Lu, Zhi

2014-01-01

The establishment of corridors can offset the negative effects of habitat fragmentation by connecting isolated habitat patches. However, the practical value of corridor planning is minimal if corridor identification is not based on reliable quantitative information about species-environment relationships. An example of this need for quantitative information is planning for giant panda conservation. Although the species has been the focus of intense conservation efforts for decades, most corridor projects remain hypothetical due to the lack of reliable quantitative researches at an appropriate spatial scale. In this paper, we evaluated a framework for giant panda forest corridor planning. We linked our field survey data with satellite imagery, and conducted species occupancy modelling to examine the habitat use of giant panda within the potential corridor area. We then conducted least-cost and circuit models to identify potential paths of dispersal across the landscape, and compared the predicted cost under current conditions and alternative conservation management options considered during corridor planning. We found that due to giant panda's association with areas of low elevation and flat terrain, human infrastructures in the same area have resulted in corridor fragmentation. We then identified areas with high potential to function as movement corridors, and our analysis of alternative conservation scenarios showed that both forest/bamboo restoration and automobile tunnel construction would significantly improve the effectiveness of corridor, while residence relocation would not significantly improve corridor effectiveness in comparison with the current condition. The framework has general value in any conservation activities that anticipate improving habitat connectivity in human modified landscapes. Specifically, our study suggested that, in this landscape, automobile tunnels are the best means to remove current barriers to giant panda movements caused by anthropogenic interferences. PMID:25133757

Trade-offs and efficiencies in optimal budget-constrained multispecies corridor networks.

PubMed

Dilkina, Bistra; Houtman, Rachel; Gomes, Carla P; Montgomery, Claire A; McKelvey, Kevin S; Kendall, Katherine; Graves, Tabitha A; Bernstein, Richard; Schwartz, Michael K

2017-02-01

Conservation biologists recognize that a system of isolated protected areas will be necessary but insufficient to meet biodiversity objectives. Current approaches to connecting core conservation areas through corridors consider optimal corridor placement based on a single optimization goal: commonly, maximizing the movement for a target species across a network of protected areas. We show that designing corridors for single species based on purely ecological criteria leads to extremely expensive linkages that are suboptimal for multispecies connectivity objectives. Similarly, acquiring the least-expensive linkages leads to ecologically poor solutions. We developed algorithms for optimizing corridors for multispecies use given a specific budget. We applied our approach in western Montana to demonstrate how the solutions may be used to evaluate trade-offs in connectivity for 2 species with different habitat requirements, different core areas, and different conservation values under different budgets. We evaluated corridors that were optimal for each species individually and for both species jointly. Incorporating a budget constraint and jointly optimizing for both species resulted in corridors that were close to the individual species movement-potential optima but with substantial cost savings. Our approach produced corridors that were within 14% and 11% of the best possible corridor connectivity for grizzly bears (Ursus arctos) and wolverines (Gulo gulo), respectively, and saved 75% of the cost. Similarly, joint optimization under a combined budget resulted in improved connectivity for both species relative to splitting the budget in 2 to optimize for each species individually. Our results demonstrate economies of scale and complementarities conservation planners can achieve by optimizing corridor designs for financial costs and for multiple species connectivity jointly. We believe that our approach will facilitate corridor conservation by reducing acquisition costs and by allowing derived corridors to more closely reflect conservation priorities. © 2016 Society for Conservation Biology.

Trade-offs and efficiencies in optimal budget-constrained multispecies corridor networks

USGS Publications Warehouse

Dilkina, Bistra; Houtman, Rachel; Gomes, Carla P.; Montgomery, Claire A.; McKelvey, Kevin; Kendall, Katherine; Graves, Tabitha A.; Bernstein, Richard; Schwartz, Michael K.

2017-01-01

Conservation biologists recognize that a system of isolated protected areas will be necessary but insufficient to meet biodiversity objectives. Current approaches to connecting core conservation areas through corridors consider optimal corridor placement based on a single optimization goal: commonly, maximizing the movement for a target species across a network of protected areas. We show that designing corridors for single species based on purely ecological criteria leads to extremely expensive linkages that are suboptimal for multispecies connectivity objectives. Similarly, acquiring the least-expensive linkages leads to ecologically poor solutions. We developed algorithms for optimizing corridors for multispecies use given a specific budget. We applied our approach in western Montana to demonstrate how the solutions may be used to evaluate trade-offs in connectivity for 2 species with different habitat requirements, different core areas, and different conservation values under different budgets. We evaluated corridors that were optimal for each species individually and for both species jointly. Incorporating a budget constraint and jointly optimizing for both species resulted in corridors that were close to the individual species movement-potential optima but with substantial cost savings. Our approach produced corridors that were within 14% and 11% of the best possible corridor connectivity for grizzly bears (Ursus arctos) and wolverines (Gulo gulo), respectively, and saved 75% of the cost. Similarly, joint optimization under a combined budget resulted in improved connectivity for both species relative to splitting the budget in 2 to optimize for each species individually. Our results demonstrate economies of scale and complementarities conservation planners can achieve by optimizing corridor designs for financial costs and for multiple species connectivity jointly. We believe that our approach will facilitate corridor conservation by reducing acquisition costs and by allowing derived corridors to more closely reflect conservation priorities.

Large-Scale Habitat Corridors for Biodiversity Conservation: A Forest Corridor in Madagascar.

PubMed

Ramiadantsoa, Tanjona; Ovaskainen, Otso; Rybicki, Joel; Hanski, Ilkka

2015-01-01

In biodiversity conservation, habitat corridors are assumed to increase landscape-level connectivity and to enhance the viability of otherwise isolated populations. While the role of corridors is supported by empirical evidence, studies have typically been conducted at small spatial scales. Here, we assess the quality and the functionality of a large 95-km long forest corridor connecting two large national parks (416 and 311 km2) in the southeastern escarpment of Madagascar. We analyze the occurrence of 300 species in 5 taxonomic groups in the parks and in the corridor, and combine high-resolution forest cover data with a simulation model to examine various scenarios of corridor destruction. At present, the corridor contains essentially the same communities as the national parks, reflecting its breadth which on average matches that of the parks. In the simulation model, we consider three types of dispersers: passive dispersers, which settle randomly around the source population; active dispersers, which settle only in favorable habitat; and gap-avoiding active dispersers, which avoid dispersing across non-habitat. Our results suggest that long-distance passive dispersers are most sensitive to ongoing degradation of the corridor, because increasing numbers of propagules are lost outside the forest habitat. For a wide range of dispersal parameters, the national parks are large enough to sustain stable populations until the corridor becomes severely broken, which will happen around 2065 if the current rate of forest loss continues. A significant decrease in gene flow along the corridor is expected after 2040, and this will exacerbate the adverse consequences of isolation. Our results demonstrate that simulation studies assessing the role of habitat corridors should pay close attention to the mode of dispersal and the effects of regional stochasticity.

Evaluating landscape options for corridor restoration between giant panda reserves.

PubMed

Wang, Fang; McShea, William J; Wang, Dajun; Li, Sheng; Zhao, Qing; Wang, Hao; Lu, Zhi

2014-01-01

The establishment of corridors can offset the negative effects of habitat fragmentation by connecting isolated habitat patches. However, the practical value of corridor planning is minimal if corridor identification is not based on reliable quantitative information about species-environment relationships. An example of this need for quantitative information is planning for giant panda conservation. Although the species has been the focus of intense conservation efforts for decades, most corridor projects remain hypothetical due to the lack of reliable quantitative researches at an appropriate spatial scale. In this paper, we evaluated a framework for giant panda forest corridor planning. We linked our field survey data with satellite imagery, and conducted species occupancy modelling to examine the habitat use of giant panda within the potential corridor area. We then conducted least-cost and circuit models to identify potential paths of dispersal across the landscape, and compared the predicted cost under current conditions and alternative conservation management options considered during corridor planning. We found that due to giant panda's association with areas of low elevation and flat terrain, human infrastructures in the same area have resulted in corridor fragmentation. We then identified areas with high potential to function as movement corridors, and our analysis of alternative conservation scenarios showed that both forest/bamboo restoration and automobile tunnel construction would significantly improve the effectiveness of corridor, while residence relocation would not significantly improve corridor effectiveness in comparison with the current condition. The framework has general value in any conservation activities that anticipate improving habitat connectivity in human modified landscapes. Specifically, our study suggested that, in this landscape, automobile tunnels are the best means to remove current barriers to giant panda movements caused by anthropogenic interferences.

Population dynamics of Microtus pennsylvanicus in corridor-linked patches

USGS Publications Warehouse

Coffman, C.J.; Nichols, J.D.; Pollock, K.H.

2001-01-01

Corridors have become a key issue in the discussion of conservation planning: however, few empirical data exist on the use of corridors and their effects on population dynamics. The objective of this replicated, population level, capture-re-capture experiment on meadow voles was to estimate and compare population characteristics of voles between (1) corridor-linked fragments, (2) isolated or non-linked fragments, and (3) unfragmented areas. We conducted two field experiments involving 22600 captures of 5700 individuals. In the first, the maintained corridor study, corridors were maintained at the time of fragmentation, and in the second, the constructed corridor study, we constructed corridors between patches that had been fragmented for some period of time. We applied multistate capture-recapture models with the robust design to estimate adult movement and survival rates, population size, temporal variation in population size, recruitment, and juvenile survival rates. Movement rates increased to a greater extent on constructed corridor-linked grids than on the unfragmented or non-linked fragmented grids between the pre- and post-treatment periods. We found significant differences in local survival on the treated (corridor-linked) grids compared to survival on the fragmented and unfragmented grids between the pre- and post-treatment periods. We found no clear pattern of treatment effects on population size or recruitment in either study. However, in both studies, we found that unfragmented grids were more stable than the fragmented grids based on lower temporal variability in population size. To our knowledge, this is the first experimental study demonstrating that corridors constructed between existing fragmented populations can indeed cause increases in movement and associated changes in demography, supporting the use of constructed corridors for this purpose in conservation biology.

76 FR 72029 - Multistate Corridor Operations and Management Program

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-21

... in the FHWA Multistate Corridor Operations and Management Program as authorized in 23 U.S.C. 511... Multistate Corridor Operations and Management Program as authorized in 23 U.S.C. 511. This notice clarifies... DEPARTMENT OF TRANSPORTATION Federal Highway Administration Multistate Corridor Operations and...

76 FR 3695 - Environmental Impact Statement: Interstate 64 Corridor, Virginia

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-20

...: Interstate 64 Corridor, Virginia AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice of Intent... Transportation for potential transportation improvements along the Interstate 64 corridor in Virginia. FOR... improvements along the Interstate 64 corridor in Virginia. The approximate limits of the study are Interstate...

45 CFR 153.530 - Risk corridors data requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 153.530 Public Welfare Department of Health and Human Services REQUIREMENTS RELATING TO HEALTH CARE ACCESS STANDARDS RELATED TO REINSURANCE, RISK CORRIDORS, AND RISK ADJUSTMENT UNDER THE AFFORDABLE CARE ACT Health Insurance Issuer Standards Related to the Risk Corridors Program § 153.530 Risk corridors...

45 CFR 153.530 - Risk corridors data requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 153.530 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS STANDARDS RELATED TO REINSURANCE, RISK CORRIDORS, AND RISK ADJUSTMENT UNDER THE AFFORDABLE CARE ACT Health Insurance Issuer Standards Related to the Risk Corridors Program § 153.530 Risk corridors...

45 CFR 153.530 - Risk corridors data requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 153.530 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS STANDARDS RELATED TO REINSURANCE, RISK CORRIDORS, AND RISK ADJUSTMENT UNDER THE AFFORDABLE CARE ACT Health Insurance Issuer Standards Related to the Risk Corridors Program § 153.530 Risk corridors...

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

Sullivan, Lauren, L.; Johnson, Brenda, L.; Brudvig, Lars, A.

Habitat corridors, a common management strategy for increasing connectivity in fragmented landscapes, have experimentally validated positive influences on species movement and diversity. However, long-standing concerns that corridors could negatively impact native species by spreading antagonists, such as disease, remain largely untested. Using a large-scale, replicated experiment, we evaluated whether corridors increase the incidence of plant parasites. We found that corridor impacts varied with parasite dispersal mode. Connectivity provided by corridors increased incidence of biotically dispersed parasites (galls on Solidago odora) but not of abiotically dispersed parasites (foliar fungi on S. odora and three Lespedeza spp.). Both biotically and abiotically dispersedmore » parasites responded to edge effects, but the direction of responses varied across species. Although our results require additional tests for generality to other species and landscapes, they suggest that, when establishing conservation corridors, managers should focus on mitigating two potential negative effects: the indirect effects of narrow corridors in creating edges and direct effects of corridors in enhancing connectivity of biotically dispersed parasites.« less

Effectiveness of a regional corridor in connecting two Florida black bear populations.

PubMed

Dixon, Jeremy D; Oli, Madan K; Wooten, Michael C; Eason, Thomas H; McCown, J Walter; Paetkau, David

2006-02-01

Corridors may mitigate the adverse effects of habitat fragmentation by restoring or maintaining connectivity between disjunct populations. The efficacy of corridors for large carnivores, however has rarely been evaluated objectively. We used noninvasive sampling, microsatellite analysis, and population assignment tests to evaluate the effectiveness of a regional corridor in connecting two Florida black bear (Ursus americanus floridanus) populations (Osceola and Ocala). Bear movement was predominantly unidirectional, with a limited mixing of individuals from the two populations in one area of the corridor We also documented bears in Osceola that were genetically assigned to Ocala and bears in Osceola that may be offspring from an Osceola-Ocala mating. Our results indicate that the Osceola-Ocala corridor is functional and provides a conduit for gene flow between these populations. Human development, however may hinder the use of the Osceola-Ocala corridor by bears. The noninvasive sampling and genetic methods we used provide a means of evaluating corridor effectiveness that can help identify linkages necessary for maintaining metapopulation structure and population viability.

Mortality patterns among residents in Louisiana's industrial corridor, USA, 1970–99

PubMed Central

Tsai, S; Cardarelli, K; Wendt, J; Fraser, A

2004-01-01

Background: Because of the high concentration of oil refining and petrochemical facilities, the industrial area of the lower Mississippi River of South Louisiana has been termed the Industrial Corridor and has frequently been referred to as the "Cancer Corridor". Aims: To quantitatively assess the "Cancer Corridor" controversy based on mortality data available in the public domain, and to identify potential contributing factors to the observed differences in mortality. Methods: Age adjusted mortality rates were calculated for white and non-white males and females in the Industrial Corridor, Louisiana, and the United States for the time periods 1970–79, 1980–89, and 1990–99. Results: All-cause mortality and all cancer combined for white males in the Industrial Corridor were significantly lower than the corresponding Louisiana population while Louisiana had significantly higher rates than the US population for all three time periods. Cancer of the lung was consistently higher in the Industrial Corridor region relative to national rates but lower than or similar to Louisiana. Non-respiratory disease and cerebrovascular disease mortality for white males in the Industrial Corridor were consistently lower than either Louisiana or the USA. However, mortality due to diabetes and heart disease, particularly during the 1990s, was significantly higher in the Industrial Corridor and Louisiana when compared to the USA. Similar mortality patterns were observed for white females. The mortality for non-white males and females in the Industrial Corridor was generally similar to the corresponding populations in Louisiana. There were no consistent patterns for all cancer mortality combined. Stomach cancer was increased among non-whites in both the Industrial Corridor and Louisiana when compared to the corresponding US data. Mortality from diabetes and heart disease among non-whites was significantly higher in the Industrial Corridor and Louisiana than in the USA. Conclusions: Mortality rates in the Industrial Corridor area were generally similar to or lower than the State of Louisiana, which were increased compared to the United States. Contrary to prior public perceptions, mortality due to cancer in the Industrial Corridor does not exceed that for the State of Louisiana. PMID:15031386

Connecting science, policy, and implementation for landscape-scale habitat connectivity.

PubMed

Brodie, Jedediah F; Paxton, Midori; Nagulendran, Kangayatkarasu; Balamurugan, G; Clements, Gopalasamy Reuben; Reynolds, Glen; Jain, Anuj; Hon, Jason

2016-10-01

We examined the links between the science and policy of habitat corridors to better understand how corridors can be implemented effectively. As a case study, we focused on a suite of landscape-scale connectivity plans in tropical and subtropical Asia (Malaysia, Singapore, and Bhutan). The process of corridor designation may be more efficient if the scientific determination of optimal corridor locations and arrangement is synchronized in time with political buy-in and establishment of policies to create corridors. Land tenure and the intactness of existing habitat in the region are also important to consider because optimal connectivity strategies may be very different if there are few, versus many, political jurisdictions (including commercial and traditional land tenures) and intact versus degraded habitat between patches. Novel financing mechanisms for corridors include bed taxes, payments for ecosystem services, and strategic forest certifications. Gaps in knowledge of effective corridor design include an understanding of how corridors, particularly those managed by local communities, can be protected from degradation and unsustainable hunting. There is a critical need for quantitative, data-driven models that can be used to prioritize potential corridors or multicorridor networks based on their relative contributions to long-term metacommunity persistence. © 2016 Society for Conservation Biology.

Suprachiasmatic translamina terminalis corridor used in endoscopic endonasal approach for resecting third ventricular craniopharyngioma.

PubMed

Gu, Ye; Zhang, Xiaobiao; Hu, Fan; Yu, Yong; Xie, Tao; Sun, Chongjing; Li, Wensheng

2015-05-01

The translamina terminalis corridor was used in the transcranial anterior route to treat third ventricular craniopharyngioma (TVC), which presents a challenge to neurosurgeons. The endoscopic endonasal approach (EEA) has recently been used to treat craniopharyngiomas. However, there are few reports of the EEA being used to treat TVC. The authors' novel surgical approach of treating selected TVC by the endoscopic endonasal route via the suprachiasmatic translamina terminalis (STLT) corridor is described. In this single-center study, the EEA via the STLT corridor was used to resect TVC with great upper and anterior extension causing bulged lamina terminalis, and TVC with a residual upper compartment, after routine infrachiasmatic transmetastalk corridor resection. The STLT corridor was used in 3 patients. Gross-total resection was achieved in all cases. One patient achieved visual improvement, and the other 2 patients showed partial visual improvement. Leakage of CSF occurred in 1 patient. Postoperative hormone replacement therapy was required in all patients. The STLT corridor is a complementary minimally invasive corridor used in the EEA for treating selected TVC. The STLT alone or combined with infrachiasmatic transmetastalk corridors should be selected depending on the size of suprachiasmatic and infrachiasmatic space.

Effects of Pleistocene environmental changes on the distribution and community structure of the mammalian fauna of Mexico

NASA Astrophysics Data System (ADS)

Ceballos, Gerardo; Arroyo-Cabrales, Joaquín; Ponce, Eduardo

2010-05-01

Biological communities in Mexico experienced profound changes in species composition and structure as a consequence of the environmental fluctuations during the Pleistocene. Based on the recent and fossil Mexican mammal checklists, we determine the distribution, composition, diversity, and community structure of late Pleistocene mammalian faunas, and analyze extinction patterns and response of individual species to environmental changes. We conclude that (1) differential extinctions occurred at family, genus, and species level, with a major impact on species heavier than 100 kg, including the extinction all proboscideans and several ruminants; (2) Pleistocene mammal communities in Mexico were more diverse than recent ones; and (3) the current assemblages of species are relatively young. Furthermore, Pleistocene relicts support the presence of biogeographic corridors; important refugia existed as well as centers of speciation in isolated regions. We identified seven corridors: eastern USA-Sierra Madre Oriental corridor, Rocky Mountains-Sierra Madre Occidental corridor, Central United States-Northern Mexico corridor, Transvolcanic Belt-Sierra Madre del Sur corridor, western USA-Baja California corridor, Tamaulipas-Central America gulf lowlands corridor, and Sonora-Central America Pacific lowlands corridor. Our study suggests that present mammalian assemblages are very different than the ones in the late Pleistocene.

Secure corridor for infraacetabular screws in acetabular fracture fixation-a 3-D radiomorphometric analysis of 124 pelvic CT datasets.

PubMed

Arlt, Stephan; Noser, Hansrudi; Wienke, Andreas; Radetzki, Florian; Hofmann, Gunther Olaf; Mendel, Thomas

2018-05-21

Acetabular fracture surgery is directed toward anatomical reduction and stable fixation to allow for the early functional rehabilitation of an injured hip joint. Recent biomechanical investigations have shown the superiority of using an additional screw in the infraacetabular (IA) region, thereby transfixing the separated columns to strengthen the construct by closing the periacetabular fixation frame. However, the inter-individual existence and variance concerning secure IA screw corridors are poorly understood. This computer-aided 3-D radiomorphometric study examined 124 CT Digital Imaging and Communications in Medicine (DICOM) datasets of intact human pelves (248 acetabula) to visualize the spatial IA corridors as the sum of all intraosseous screw positions. DICOM files were pre-processed using the Amira® 4.2 visualization software. Final corridor computation was accomplished using a custom-made software algorithm. The volumetric measurement data of each corridor were calculated for further statistical analyses. Correlations between the volumetric values and the biometric data were investigated. Furthermore, the influence of hip dysplasia on the IA corridor configuration was analyzed. The IA corridors consistently showed a double-cone shape with the isthmus located at the acetabular fovea. In 97% of male and 91% of female acetabula, a corridor for a 3.5-mm screw could be found. The number of IA corridors was significantly lower in females for screw diameters ≥ 4.5 mm. The mean 3.5-mm screw corridor volume was 16 cm 3 in males and 9.2 cm 3 in female pelves. Corridor volumes were significantly positively correlated with body height and weight and with the diameter of Köhler's teardrop on standard AP pelvic X-rays. No correlation was observed between hip dysplasia and the IA corridor extent. IA corridors are consistently smaller in females. However, 3.5-mm small fragment screws may still be used as the standard implant because sex-specific differences are significant only with screw diameters ≥ 4.5 mm. Congenital hip dysplasia does not affect secure IA screw insertion. The described method allows 3-D shape analyses with highly reliable results. The visualization of secure IA corridors may support the spatial awareness of surgeons. Volumetric data allow the reliable assessment of individual IA corridors using standard AP X-ray views, which aids preoperative planning.

45 CFR 800.204 - Reinsurance, risk corridors, and risk adjustment.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 3 2013-10-01 2013-10-01 false Reinsurance, risk corridors, and risk adjustment... Adjustment § 800.204 Reinsurance, risk corridors, and risk adjustment. (a) Transitional reinsurance program... transitional reinsurance program for the individual market. (b) Temporary risk corridors program. An MSPP...

45 CFR 800.204 - Reinsurance, risk corridors, and risk adjustment.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 3 2014-10-01 2014-10-01 false Reinsurance, risk corridors, and risk adjustment... Adjustment § 800.204 Reinsurance, risk corridors, and risk adjustment. (a) Transitional reinsurance program... transitional reinsurance program for the individual market. (b) Temporary risk corridors program. An MSPP...

UNICOR: a species connectivity and corridor network simulator

Treesearch

E. L. Landguth; B. K. Hand; J. Glassy; S. A. Cushman; M. A. Sawaya

2012-01-01

We introduce UNIversal CORridor network simulator (UNICOR), a species connectivity and corridor identifi cation tool. UNICOR applies Dijkstra's shortest path algorithm to individual-based simulations. Outputs can be used to designate movement corridors, identify isolated populations, and prioritize conservation plans to promote species persistence. The key...

Study design and preliminary data analysis for a streambank fencing project in the Mill Creek Basin, Pennsylvania

USGS Publications Warehouse

Galeone, Daniel G.; Koerkle, Edward H.

1996-01-01

The Pequea Creek and Mill Creek Basins within Lancaster and Chester Counties in Pennsylvania have been identified as areas needing control of nonpoint-source (NFS) pollution to improve water quality. The two basins are a total of approximately 200 square miles and are primarily underlain by carbonate bedrock. Land use is predominantly agriculture. The most common agricultural NFS pollution-control practices implemented in the Pequea Creek and Mill Creek Basins are barnyard-runoff control and Streambank fencing. To provide land managers information on the effectiveness of Streambank fencing in controlling NFS pollution, a study is being conducted in two small paired watersheds within the Mill Creek Basin.

China Pakistan Economic Corridor (CPEC): Benefits For Pakistan And Comparison With Suez And Panama Canals

DTIC Science & Technology

2017-12-01

ECONOMIC CORRIDOR (CPEC): BENEFITS FOR PAKISTAN AND COMPARISON WITH SUEZ AND PANAMA CANALS by Hanif Ullah Khan December 2017 Thesis...DATE December 2017 3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE CHINA PAKISTAN ECONOMIC CORRIDOR (CPEC): BENEFITS FOR...The China Pakistan Economic Corridor (CPEC) is part of China’s “One Belt, One Road” initiative and joins two major economic corridors: The Silk Road

Identification of functional corridors with movement characteristics of brown bears on the Kenai Peninsula, Alaska

USGS Publications Warehouse

Graves, T.A.; Farley, S.; Goldstein, M.I.; Servheen, C.

2007-01-01

We identified primary habitat and functional corridors across a landscape using Global Positioning System (GPS) collar locations of brown bears (Ursus arctos). After deriving density, speed, and angular deviation of movement, we classified landscape function for a group of animals with a cluster analysis. We described areas with high amounts of sinuous movement as primary habitat patches and areas with high amounts of very directional, fast movement as highly functional bear corridors. The time between bear locations and scale of analysis influenced the number and size of corridors identified. Bear locations should be collected at intervals ???6 h to correctly identify travel corridors. Our corridor identification technique will help managers move beyond the theoretical discussion of corridors and linkage zones to active management of landscape features that will preserve connectivity. ?? 2007 Springer Science+Business Media, Inc.

The impact of deer browsing on Allegheny hardwood regeneration

Treesearch

David A. Marquis

1974-01-01

To evaluate the impact of deer browsing on Allegheny hardwood regeneration, surveys were made of vegetation inside and outside deer exclosures in 13 stands that had been clearcut 5 to 16 years earlier. The surveys showed that browsing by white-tailed deer has resulted in regeneration failures in 25 to 40 percent of the areas studied. Pin cherry and sugar maple were the...

Plant-herbivore-hydroperiod interactions: effects of native mammals on floodplain tree recruitment

USGS Publications Warehouse

Andersen, D.C.; Cooper, D.J.

2000-01-01

Floodplain plant–herbivore–hydroperiod interactions have received little attention despite their potential as determinants of floodplain structure and functioning. We used five types of exclosures to differentially exclude small-, medium-, and large-sized mammals from accessing Fremont cottonwood (Populus deltoides Marshall subsp. wizlizenii (Watson) Eckenwalder) seedlings and saplings growing naturally on four landform types at an alluvial reach on each of two rivers, the Green and Yampa, in Colorado and Utah. The two study reaches differed primarily as a result of flow regulation on the Green River, which began in 1962. Landforms were a rarely flooded portion of the alluvial plain, geomorphically active slow- and fast-water channel margin sites on the Yampa reach, and an aggrading side channel on the Green. Small-mammal live-trapping and observational data indicated that, with minor exceptions, the kinds of mammals eating cottonwood within each reach were identical. We monitored condition and fates of individual cottonwood plants from October 1993 through the 1997 growing season. Differences in survival and growth were noted both within and between reaches, and both due to, and independent of, mammalian herbivory. Comparisons of cottonwood growth and survivorship among exclosures and between exclosures and controls indicated that a small mammal, Microtus montanus, reduced seedling and sapling survivorship at the Green River reach, but to a lesser extent (seedlings) or not at all (saplings) on the Yampa reach. In contrast, reductions in sapling height increment attributable to medium- and large-sized herbivores were detected only at the Yampa site. We suggest that these differences are a result of (1) flow regulation allowing Microtus populations to escape the mortality normally accompanying the large, snowmelt-driven spring flood, as well as regulation promoting a herbaceous understory favorable to voles, and (2) greater browsing pressure from overwintering deer and elk at the Yampa reach, unrelated to flow regulation. Within areas used by foraging beaver, the probability of a sapling being cut by beaver was similar on the two reaches. This study suggests that changes in riparian plant–herbivore relationships due to shifts in river hydrology may be a common and important consequence of river regulation.

Effects of elk herbivory on vegetation and nitrogen processes

USGS Publications Warehouse

Schoenecker, Kathryn A.; Singer, Francis J.; Zeigenfuss, Linda C.; Binkley, Dan; Menezes, Romulo S.C.

2004-01-01

We used 35-year and 4-year ungulate exclosures to determine the effects of elk (Cervus elaphus) herbivory on above-ground and below-ground production and soil fertility on the elk winter range in Rocky Mountain National Park (RMNP), Colorado, USA. We used paired grazed and ungrazed plots to evaluate ungulate herbivory effects in short and tall willow (Salix spp.), aspen (Populus spp.), and upland grass/shrub vegetation associations. We measured nitrogen (N) fluxes (litter deposition, fecal and urinary deposition from elk, movements of N by elk, N mineralization, soil N availability, elk consumption rates) within the elk winter, above-ground and below-ground N pools (herbaceous, shrub and root biomass, %N in plants, roots, and soil), and N fluxes on and off the elk winter range (seasonal movement of N by elk). Nitrogen mineralization and soil nitrate (NO3) pools were reduced in the short willow community (P = 0.07 and 0.10, respectively; n = 4 sites) in grazed plots, but not in the upland grass/shrub community or tall willow sites (P >0.10). Annual growth of willows was reduced by 98% in grazed plots, relative to 35-year exclosures, and 66% relative to 4-year exclosures. Thus, height, canopy size, and litter biomass of willows were reduced, and N yield of willows was 64% less in grazed plots. We evaluated movement of N by elk among 6 major vegetation associations and found that elk grazed more and bedded less in willow vegetation association compared to mixed conifer, mesic meadow, and grassland/shrub associations (P = 0.014, 0.001, and 0.026, respectively), suggesting that elk herbivory and movement led to a net loss of N in the willow vegetation association. Elk spent less total time in willows than mesic meadow association, yet they consumed large amounts of willow plant biomass. We recommend management of elk numbers and elk herbivory that takes into consideration impacts to N process function, as negative effects from current levels of herbivory were observed in ≥1 of 3 vegetation associations studied.

Designing large-scale conservation corridors for pattern and process.

PubMed

Rouget, Mathieu; Cowling, Richard M; Lombard, Amanda T; Knight, Andrew T; Kerley, Graham I H

2006-04-01

A major challenge for conservation assessments is to identify priority areas that incorporate biological patterns and processes. Because large-scale processes are mostly oriented along environmental gradients, we propose to accommodate them by designing regional-scale corridors to capture these gradients. Based on systematic conservation planning principles such as representation and persistence, we identified large tracts of untransformed land (i.e., conservation corridors) for conservation that would achieve biodiversity targets for pattern and process in the Subtropical Thicket Biome of South Africa. We combined least-cost path analysis with a target-driven algorithm to identify the best option for capturing key environmental gradients while considering biodiversity targets and conservation opportunities and constraints. We identified seven conservation corridors on the basis of subtropical thicket representation, habitat transformation and degradation, wildlife suitability, irreplaceability of vegetation types, protected area networks, and future land-use pressures. These conservation corridors covered 21.1% of the planning region (ranging from 600 to 5200 km2) and successfully achieved targets for biological processes and to a lesser extent for vegetation types. The corridors we identified are intended to promote the persistence of ecological processes (gradients and fixed processes) and fulfill half of the biodiversity pattern target. We compared the conservation corridors with a simplified corridor design consisting of a fixed-width buffer along major rivers. Conservation corridors outperformed river buffers in seven out of eight criteria. Our corridor design can provide a tool for quantifying trade-offs between various criteria (biodiversity pattern and process, implementation constraints and opportunities). A land-use management model was developed to facilitate implementation of conservation actions within these corridors.

Dispersal corridors for plant species in the Poyang Lake Basin of southeast China identified by integration of phylogeographic and geospatial data.

PubMed

Fan, Dengmei; Sun, Zhixia; Li, Bo; Kou, Yixuan; Hodel, Richard G J; Jin, Zhinong; Zhang, Zhiyong

2017-07-01

Measuring the dispersal of wildlife through landscapes is notoriously difficult. Recently, the categorical least cost path algorithm that integrates population genetic data with species distribution models has been applied to reveal population connectivity. In this study, we use this method to identify the possible dispersal corridors of five plant species ( Castanopsis tibetana , Schima superba , Cyclocarya paliurus , Sargentodoxa cuneata , Eomecon chionantha ) in the Poyang Lake Basin (PLB, largely coinciding with Jiangxi Province), China, in the late Quaternary. The results showed that the strongest population connectivity for the five species occurred in the Wuyi Mountains and the Yu Mountains of the eastern PLB (East Corridor) during the late Quaternary. In the western PLB, populations of the five species were connected by the Luoxiao Mountains and the Jiuling Mountains (West Corridor) but with a lower degree of connectivity. There were some minor connections between the eastern and the western populations across the Gannan Hills. When the corridors of five species were overlaid, the East Corridor and the West Corridor were mostly shared by multiple species. These results indicate that plant species in the PLB could have responded to the Quaternary climate changes by moving along the East Corridor and the West Corridor. Given that dispersal corridors have seldom been considered in the governmental strategies of biodiversity conservation in the PLB, preserving and restoring natural vegetation along these corridors should be prioritized to mitigate the effects of anthropogenic climate change by facilitating migration of plant species and other biota.

Bison phylogeography constrains dispersal and viability of the Ice Free Corridor in western Canada

PubMed Central

Froese, Duane; Ives, John W.; Zazula, Grant D.; Letts, Brandon; Andrews, Thomas D.; Driver, Jonathan C.; Hall, Elizabeth; Hare, P. Gregory; Jass, Christopher N.; MacKay, Glen; Southon, John R.; Stiller, Mathias; Woywitka, Robin; Suchard, Marc A.

2016-01-01

The Ice Free Corridor has been invoked as a route for Pleistocene human and animal dispersals between eastern Beringia and more southerly areas of North America. Despite the significance of the corridor, there are limited data for when and how this corridor was used. Hypothetical uses of the corridor include: the first expansion of humans from Beringia into the Americas, northward postglacial expansions of fluted point technologies into Beringia, and continued use of the corridor as a contact route between the north and south. Here, we use radiocarbon dates and ancient mitochondrial DNA from late Pleistocene bison fossils to determine the chronology for when the corridor was open and viable for biotic dispersals. The corridor was closed after ∼23,000 until 13,400 calendar years ago (cal y BP), after which we find the first evidence, to our knowledge, that bison used this route to disperse from the south, and by 13,000 y from the north. Our chronology supports a habitable and traversable corridor by at least 13,000 cal y BP, just before the first appearance of Clovis technology in interior North America, and indicates that the corridor would not have been available for significantly earlier southward human dispersal. Following the opening of the corridor, multiple dispersals of human groups between Beringia and interior North America may have continued throughout the latest Pleistocene and early Holocene. Our results highlight the utility of phylogeographic analyses to test hypotheses about paleoecological history and the viability of dispersal routes over time. PMID:27274051

Bison phylogeography constrains dispersal and viability of the Ice Free Corridor in western Canada.

PubMed

Heintzman, Peter D; Froese, Duane; Ives, John W; Soares, André E R; Zazula, Grant D; Letts, Brandon; Andrews, Thomas D; Driver, Jonathan C; Hall, Elizabeth; Hare, P Gregory; Jass, Christopher N; MacKay, Glen; Southon, John R; Stiller, Mathias; Woywitka, Robin; Suchard, Marc A; Shapiro, Beth

2016-07-19

The Ice Free Corridor has been invoked as a route for Pleistocene human and animal dispersals between eastern Beringia and more southerly areas of North America. Despite the significance of the corridor, there are limited data for when and how this corridor was used. Hypothetical uses of the corridor include: the first expansion of humans from Beringia into the Americas, northward postglacial expansions of fluted point technologies into Beringia, and continued use of the corridor as a contact route between the north and south. Here, we use radiocarbon dates and ancient mitochondrial DNA from late Pleistocene bison fossils to determine the chronology for when the corridor was open and viable for biotic dispersals. The corridor was closed after ∼23,000 until 13,400 calendar years ago (cal y BP), after which we find the first evidence, to our knowledge, that bison used this route to disperse from the south, and by 13,000 y from the north. Our chronology supports a habitable and traversable corridor by at least 13,000 cal y BP, just before the first appearance of Clovis technology in interior North America, and indicates that the corridor would not have been available for significantly earlier southward human dispersal. Following the opening of the corridor, multiple dispersals of human groups between Beringia and interior North America may have continued throughout the latest Pleistocene and early Holocene. Our results highlight the utility of phylogeographic analyses to test hypotheses about paleoecological history and the viability of dispersal routes over time.

43 CFR 2802.11 - How does BLM designate corridors?

Code of Federal Regulations, 2013 CFR

2013-10-01

... air, water, soil, fish, wildlife, and vegetation; (3) Physical effects and constraints on corridor... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false How does BLM designate corridors? 2802.11... POLICY MANAGEMENT ACT Lands Available for FLPMA Grants § 2802.11 How does BLM designate corridors? (a...

43 CFR 2802.11 - How does BLM designate corridors?

Code of Federal Regulations, 2012 CFR

2012-10-01

... air, water, soil, fish, wildlife, and vegetation; (3) Physical effects and constraints on corridor... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false How does BLM designate corridors? 2802.11... POLICY MANAGEMENT ACT Lands Available for FLPMA Grants § 2802.11 How does BLM designate corridors? (a...

43 CFR 2802.11 - How does BLM designate corridors?

Code of Federal Regulations, 2011 CFR

2011-10-01

... air, water, soil, fish, wildlife, and vegetation; (3) Physical effects and constraints on corridor... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false How does BLM designate corridors? 2802.11... POLICY MANAGEMENT ACT Lands Available for FLPMA Grants § 2802.11 How does BLM designate corridors? (a...

Analysis of Florida Department of Transportation transit corridor program/projects : technical memorandum number one - review and summary of transit corridor plans

DOT National Transportation Integrated Search

2001-05-01

The purpose of this project was to undertake a consolidated comprehensive review of the Florida Department of Transportation Transit Corridor Program. Technical Memorandum Number One provides a summary of all transit corridor projects either under wa...

14 CFR 93.321 - Transfer and termination of allocations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... commercial air tours outside the Dragon and Zuni Point corridors may not be transferred into the Dragon and Zuni Point corridors. Allocations authorizing commercial air tours within the Dragon and Zuni Point corridors may be transferred outside of the Dragon and Zuni Point corridors. (iii) A certificate holder must...

14 CFR 93.321 - Transfer and termination of allocations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... commercial air tours outside the Dragon and Zuni Point corridors may not be transferred into the Dragon and Zuni Point corridors. Allocations authorizing commercial air tours within the Dragon and Zuni Point corridors may be transferred outside of the Dragon and Zuni Point corridors. (iii) A certificate holder must...

46 CFR 92.10-30 - Dead end corridors.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Dead end corridors. 92.10-30 Section 92.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 92.10-30 Dead end corridors. (a) Dead end corridors, or the...

46 CFR 92.10-30 - Dead end corridors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Dead end corridors. 92.10-30 Section 92.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 92.10-30 Dead end corridors. (a) Dead end corridors, or the...

46 CFR 92.10-30 - Dead end corridors.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Dead end corridors. 92.10-30 Section 92.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 92.10-30 Dead end corridors. (a) Dead end corridors, or the...

46 CFR 108.161 - Dead end corridors.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Dead end corridors. 108.161 Section 108.161 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.161 Dead end corridors. No dead end corridor...

46 CFR 108.161 - Dead end corridors.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Dead end corridors. 108.161 Section 108.161 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.161 Dead end corridors. No dead end corridor...

46 CFR 108.161 - Dead end corridors.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Dead end corridors. 108.161 Section 108.161 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.161 Dead end corridors. No dead end corridor...

46 CFR 92.10-30 - Dead end corridors.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Dead end corridors. 92.10-30 Section 92.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 92.10-30 Dead end corridors. (a) Dead end corridors, or the...

46 CFR 108.161 - Dead end corridors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Dead end corridors. 108.161 Section 108.161 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.161 Dead end corridors. No dead end corridor...

46 CFR 92.10-30 - Dead end corridors.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Dead end corridors. 92.10-30 Section 92.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 92.10-30 Dead end corridors. (a) Dead end corridors, or the...

46 CFR 108.161 - Dead end corridors.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Dead end corridors. 108.161 Section 108.161 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.161 Dead end corridors. No dead end corridor...

4. Corridor B. Perspective of west side as viewed from ...

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

4. Corridor B. Perspective of west side as viewed from roof of Building No. 9982. The flat-roof building that joins Corridor B is Building No. 9981, Receiving and Evacuation Building. - Madigan Hospital, Corridors & Ramps, Bounded by Wilson & McKinley Avenues & Garfield & Lincoln Streets, Tacoma, Pierce County, WA

14 CFR 93.321 - Transfer and termination of allocations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... commercial air tours outside the Dragon and Zuni Point corridors may not be transferred into the Dragon and Zuni Point corridors. Allocations authorizing commercial air tours within the Dragon and Zuni Point corridors may be transferred outside of the Dragon and Zuni Point corridors. (iii) A certificate holder must...

14 CFR 93.321 - Transfer and termination of allocations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... commercial air tours outside the Dragon and Zuni Point corridors may not be transferred into the Dragon and Zuni Point corridors. Allocations authorizing commercial air tours within the Dragon and Zuni Point corridors may be transferred outside of the Dragon and Zuni Point corridors. (iii) A certificate holder must...

Integrated corridor management : analysis, modeling, and simulation for the U.S.-75 corridor in Dallas, Texas – post-deployment assessment report.

DOT National Transportation Integrated Search

2016-11-01

The U.S. Department of Transportation Integrated Corridor Management (ICM) Initiative aims to advance the state of the practice in transportation corridor operations to manage congestion. Through the deployment of ICM at the two selected Demonstratio...

Integrated corridor management analysis, modeling, and simulation for the I-15 corridor in San Diego, California post-deployment assessment report.

DOT National Transportation Integrated Search

2016-12-01

The U.S. Department of Transportation Integrated Corridor Management (ICM) Initiative aims to advance the state of the practice in transportation corridor operations to manage congestion. Through the deployment of ICM at the two selected Demonstratio...

Corridor Length and Patch Colonization by a Butterfly, Junonia coenia

Treesearch

Nick Haddad

2000-01-01

Corridors have been proposed to reduce isolation and increase population persistence in fragmented landscapes, yet little research has evaluated the types of landscapes in which corridors will be most effective. I tested the hypothesis that corridors increase patch colonization by a butterfly, Junonia coenia, regardless of the butterfly's...

77 FR 55265 - Environmental Impact Statement for the Northeast Corridor Between Washington, DC, New York, NY...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-07

... the Northeast Corridor Between Washington, DC, New York, NY, and Boston, MA AGENCY: Federal Railroad... ). SUPPLEMENTARY INFORMATION: FRA is leading the planning and environmental evaluation of the Northeast Corridor (NEC) in close coordination with the involved states, Northeast Corridor Infrastructure and Operations...

76 FR 29290 - Environmental Impact Statement: Interstate 64 Hampton Roads Bridge Tunnel Corridor, Virginia

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-20

...: Interstate 64 Hampton Roads Bridge Tunnel Corridor, Virginia AGENCY: Federal Highway Administration (FHWA... Interstate 64 Hampton Roads Bridge Tunnel (HRBT) corridor in Virginia. FOR FURTHER INFORMATION CONTACT... Interstate 64 Hampton Roads Bridge Tunnel (HRBT) corridor in Virginia. The approximate limits of the study...

Installation Flightline Fence Finding of No Significant Impact (FONSI)

DTIC Science & Technology

2003-07-28

Georgia Street,Moody AFB, GA ,31699 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR...Environmental Protection Committee Finding of No Sign~ficant Impact Installation Flightline Fence Moody Air Force Base, GA Environmental Assessment...Water Resources/Wetlands - Compliance Resources Moody Air Force Base, GA Environmental Assessment

The Chain-Link Fence Model: A Framework for Creating Security Procedures

ERIC Educational Resources Information Center

Houghton, Robert F.

2013-01-01

A long standing problem in information technology security is how to help reduce the security footprint. Many specific proposals exist to address specific problems in information technology security. Most information technology solutions need to be repeatable throughout the course of an information systems lifecycle. The Chain-Link Fence Model is…

"Rabbit Proof Fence": A Struggle for Cultural Existence

ERIC Educational Resources Information Center

Al-Momani, Hassan Ali Abdullah

2016-01-01

The main goal of this paper is to depict the struggle for cultural existence in "Rabbit Proof Fence." It also reflects the cultural conflict represented in the three aboriginal girls' characters which is due to their rejection and resistance for the colonialists' culture. Besides, the paper presents the cognitive analysis of the cultural…

Exploring Postcolonial and Feminist Issues: "Rabbit-Proof Fence" in a Teaching Context

ERIC Educational Resources Information Center

Beyer, Charlotte

2010-01-01

The discussion in this article focuses on representations in Doris Pilkington's "Rabbit-Proof Fence" of trauma and reparation, and reflects on processes and strategies involved in teaching undergraduate students about these issues within literary contexts. The article discusses the practice of introducing students to new texts and areas…

Stress Reduction and Mood Enhancement in Four Exercise Modes: Swimming, Body Conditioning, Hatha Yoga, and Fencing.

ERIC Educational Resources Information Center

Berger, Bonnie G.; Owen, David R.

1988-01-01

Differences in mood before and after class of college students taking different courses (swimming, body conditioning, hatha yoga, fencing exercise, and lecture) were analyzed using the Profile Mood States and the State Anxiety Inventory. Results suggest that courses which meet four requirements involving aerobics, noncompetitiveness,…

5. Inside perimeter fence, view towards northeast, EMP antenna at ...

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

5. Inside perimeter fence, view towards northeast, EMP antenna at center, top of soft support building visible at left center - Ellsworth Air Force Base, Delta Flight, Launch Facility D-6, 4 miles north of Badlands National Park Headquarters, 4.5 miles east of Jackson County line on county road, Interior, Jackson County, SD

What Was It like? Being in the Pioneer Class at UC Merced

ERIC Educational Resources Information Center

Perry, Lisa

2007-01-01

Entering the UC Merced campus and turning onto Scholars Lane, students saw, in this order, large cow pastures surrounding the campus, tall chainlink fences enclosing construction materials, orange fences stating "limits of construction," and across the small road, the residence facilities. Students who were willing to brave this…

Do wire fences stop ground fires?

Treesearch

James L. Murphy; Harry E. Schimke

1965-01-01

Five meshes (1/8 to 1 inch) of 16-gauge steel wire fences, 3 feet high, were tested as possible ground fire barriers in 4 fuel types. The 1/8-inch mesh stopped only 1 test fire but retarded others; 1/4-inch mesh retarded some. The results suggest that further trials may be worthwhile.

Compensated intruder-detection systems

DOEpatents

McNeilly, David R.; Miller, William R.

1984-01-01

Intruder-detection systems in which intruder-induced signals are transmitted through a medium also receive spurious signals induced by changes in a climatic condition affecting the medium. To combat this, signals received from the detection medium are converted to a first signal. The system also provides a reference signal proportional to climate-induced changes in the medium. The first signal and the reference signal are combined for generating therefrom an output signal which is insensitive to the climatic changes in the medium. An alarm is energized if the output signal exceeds a preselected value. In one embodiment, an acoustic cable is coupled to a fence to generate a first electrical signal proportional to movements thereof. False alarms resulting from wind-induced movements of the fence (detection medium) are eliminated by providing an anemometer-driven voltage generator to provide a reference voltage proportional to the velocity of wind incident on the fence. An analog divider receives the first electrical signal and the reference signal as its numerator and denominator inputs, respectively, and generates therefrom an output signal which is insensitive to the wind-induced movements in the fence.

CFD analysis on control of secondary losses in STME LOX turbines with endwall fences

NASA Technical Reports Server (NTRS)

Chyu, Mingking K.

1992-01-01

The rotor blade in the newly designed LOX turbine for the future Space Transportation Main Engine (STME) has a severe flow turning angle, nearly 160 degrees. The estimated secondary loss in the rotor alone accounts for nearly 50 percent of the total loss over the entire stage. To reduce such a loss, one of the potential methods is to use fences attached on the turbine endwall (hub). As a prelude to examining the effects of endwall fence with actual STME turbine configuration, the present study focuses on similar issues with a different, but more generic, geometry - a rectangular duct with a 160-degree bend. The duct cross-section has a 2-to-1 aspect ratio and the radii of curvature for the inner and outer wall are 0.25 and 1.25 times the duct width, respectively. The present emphasis lies in examining the effects of various fence-length extending along the streamwise direction. The flowfield is numerically simulated using the FDNS code developed earlier by Wang and Chen. The FDNS code is a pressure based, finite-difference, Navier-Stokes equations solver.

Automatic detection of MLC relative position errors for VMAT using the EPID-based picket fence test

NASA Astrophysics Data System (ADS)

Christophides, Damianos; Davies, Alex; Fleckney, Mark

2016-12-01

Multi-leaf collimators (MLCs) ensure the accurate delivery of treatments requiring complex beam fluences like intensity modulated radiotherapy and volumetric modulated arc therapy. The purpose of this work is to automate the detection of MLC relative position errors  ⩾0.5 mm using electronic portal imaging device-based picket fence tests and compare the results to the qualitative assessment currently in use. Picket fence tests with and without intentional MLC errors were measured weekly on three Varian linacs. The picket fence images analysed covered a time period ranging between 14-20 months depending on the linac. An algorithm was developed that calculated the MLC error for each leaf-pair present in the picket fence images. The baseline error distributions of each linac were characterised for an initial period of 6 months and compared with the intentional MLC errors using statistical metrics. The distributions of median and one-sample Kolmogorov-Smirnov test p-value exhibited no overlap between baseline and intentional errors and were used retrospectively to automatically detect MLC errors in routine clinical practice. Agreement was found between the MLC errors detected by the automatic method and the fault reports during clinical use, as well as interventions for MLC repair and calibration. In conclusion the method presented provides for full automation of MLC quality assurance, based on individual linac performance characteristics. The use of the automatic method has been shown to provide early warning for MLC errors that resulted in clinical downtime.

Experimental study designs to improve the evaluation of road mitigation measures for wildlife.

PubMed

Rytwinski, Trina; van der Ree, Rodney; Cunnington, Glenn M; Fahrig, Lenore; Findlay, C Scott; Houlahan, Jeff; Jaeger, Jochen A G; Soanes, Kylie; van der Grift, Edgar A

2015-05-01

An experimental approach to road mitigation that maximizes inferential power is essential to ensure that mitigation is both ecologically-effective and cost-effective. Here, we set out the need for and standards of using an experimental approach to road mitigation, in order to improve knowledge of the influence of mitigation measures on wildlife populations. We point out two key areas that need to be considered when conducting mitigation experiments. First, researchers need to get involved at the earliest stage of the road or mitigation project to ensure the necessary planning and funds are available for conducting a high quality experiment. Second, experimentation will generate new knowledge about the parameters that influence mitigation effectiveness, which ultimately allows better prediction for future road mitigation projects. We identify seven key questions about mitigation structures (i.e., wildlife crossing structures and fencing) that remain largely or entirely unanswered at the population-level: (1) Does a given crossing structure work? What type and size of crossing structures should we use? (2) How many crossing structures should we build? (3) Is it more effective to install a small number of large-sized crossing structures or a large number of small-sized crossing structures? (4) How much barrier fencing is needed for a given length of road? (5) Do we need funnel fencing to lead animals to crossing structures, and how long does such fencing have to be? (6) How should we manage/manipulate the environment in the area around the crossing structures and fencing? (7) Where should we place crossing structures and barrier fencing? We provide experimental approaches to answering each of them using example Before-After-Control-Impact (BACI) study designs for two stages in the road/mitigation project where researchers may become involved: (1) at the beginning of a road/mitigation project, and (2) after the mitigation has been constructed; highlighting real case studies when available. Copyright © 2015 Elsevier Ltd. All rights reserved.

How Corridors Reduce Indigo Bunting Nest Success.

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

Weldon, Aimee, J.

2006-08-01

Abstract: Corridors are a popular strategy to conserve biodiversity and promote gene flow in fragmented landscapes. Corridor effectiveness has been bolstered by the fact that no empirical field studies have shown negative effects on populations or communities. I tested the hypothesis that corridors increase nest predation in connected habitat fragments relative to unconnected fragments. I evaluated this hypothesis in a large-scale experimental system of open-habitat fragments that varied in shape and connectivity. Corridors increased nest predation rates in connected fragments relative to unconnected fragments with lower edge:area ratios. Nest predation rates were similar between connected and unconnected fragments with highermore » edge:area ratios. These results suggest that the increase in predator activity is largely attributable to edge effects incurred through the addition of a corridor. This is the first field study to demonstrate that corridors can negatively impact animal populations occupying connected fragments.« less

Hierarchically porous Fe-N-C derived from covalent-organic materials as a highly efficient electrocatalyst for oxygen reduction

NASA Astrophysics Data System (ADS)

Zuo, Quan; Zhao, Pingping; Luo, Wei; Cheng, Gongzhen

2016-07-01

Developing high-performance non-precious catalysts to replace platinum as oxygen reduction reaction (ORR) catalysts is still a big scientific and technological challenge. Herein, we report a simple method for the synthesis of a FeNC catalyst with a 3D hierarchically micro/meso/macro porous network and high surface area through a simple carbonization method by taking the advantages of a high specific surface area and diverse pore dimensions in 3D porous covalent-organic material. The resulting FeNC-900 electrocatalyst with improved reactant/electrolyte transport and sufficient active site exposure, exhibits outstanding ORR activity with a half-wave potential of 0.878 V, ca. 40 mV more positive than Pt/C for ORR in alkaline solution, and a half-wave potential of 0.72 V, which is comparable to that of Pt/C in acidic solution. In particular, the resulting FeNC-900 exhibits a much higher stability and methanol tolerance than those of Pt/C, which makes it among the best non-precious catalysts ever reported for ORR.Developing high-performance non-precious catalysts to replace platinum as oxygen reduction reaction (ORR) catalysts is still a big scientific and technological challenge. Herein, we report a simple method for the synthesis of a FeNC catalyst with a 3D hierarchically micro/meso/macro porous network and high surface area through a simple carbonization method by taking the advantages of a high specific surface area and diverse pore dimensions in 3D porous covalent-organic material. The resulting FeNC-900 electrocatalyst with improved reactant/electrolyte transport and sufficient active site exposure, exhibits outstanding ORR activity with a half-wave potential of 0.878 V, ca. 40 mV more positive than Pt/C for ORR in alkaline solution, and a half-wave potential of 0.72 V, which is comparable to that of Pt/C in acidic solution. In particular, the resulting FeNC-900 exhibits a much higher stability and methanol tolerance than those of Pt/C, which makes it among the best non-precious catalysts ever reported for ORR. Electronic supplementary information (ESI) available: Fig. S1-S12 and Tables S1 and S2. See DOI: 10.1039/c6nr03273g

Towards a definition of biological corridor

Treesearch

D.K. Rosenberg; B.R. Noon; E.C. Meslow

1995-01-01

Lack of clear, unambiguous criteria that distinguishes a linear habitat patch as a corridor contributes to controversy over the value of corridors for wildlife conservation. The definitions of biological corridors have been vague or inconsistent, and often they confound form and function. Explicit criteria that can differentiate between a linear habitat patch and a...

46 CFR 190.10-30 - Dead end corridors.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Dead end corridors. 190.10-30 Section 190.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 190.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more...

46 CFR 190.10-30 - Dead end corridors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Dead end corridors. 190.10-30 Section 190.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 190.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more...

46 CFR 72.10-30 - Dead end corridors.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 3 2010-10-01 2010-10-01 false Dead end corridors. 72.10-30 Section 72.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 72.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more than 40...

46 CFR 72.10-30 - Dead end corridors.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 3 2013-10-01 2013-10-01 false Dead end corridors. 72.10-30 Section 72.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 72.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more than 40...

46 CFR 190.10-30 - Dead end corridors.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Dead end corridors. 190.10-30 Section 190.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 190.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more...

46 CFR 72.10-30 - Dead end corridors.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 3 2012-10-01 2012-10-01 false Dead end corridors. 72.10-30 Section 72.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 72.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more than 40...

46 CFR 190.10-30 - Dead end corridors.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Dead end corridors. 190.10-30 Section 190.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 190.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more...

46 CFR 72.10-30 - Dead end corridors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 3 2011-10-01 2011-10-01 false Dead end corridors. 72.10-30 Section 72.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 72.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more than 40...

46 CFR 190.10-30 - Dead end corridors.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Dead end corridors. 190.10-30 Section 190.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 190.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more...

46 CFR 72.10-30 - Dead end corridors.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 3 2014-10-01 2014-10-01 false Dead end corridors. 72.10-30 Section 72.10-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT Means of Escape § 72.10-30 Dead end corridors. (a) Dead end corridors, or the equivalent, more than 40...

View looking south along the main corridor on the third ...

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

View looking south along the main corridor on the third floor of the south wing. The openings along the top of the corridor walls allowed for the movement of air and light between the corridor and the resident rooms. - U. S. Naval Asylum, Biddle Hall, Gray's Ferry Avenue, Philadelphia, Philadelphia County, PA

24. Interior view of entrance corridor looking down east corridor; ...

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

24. Interior view of entrance corridor looking down east corridor; showing unoccupied corner office space and stairs going down to lower floor; center of main section of building on main floor; view to northeast. - Ellsworth Air Force Base, Group Administration & Secure Storage Building, 2372 Westover Avenue, Blackhawk, Meade County, SD

76 FR 31009 - Iowa Northern Railway Company-Operation Exemption-North Central Iowa Rail Corridor, LLC

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-27

... Railway Company--Operation Exemption--North Central Iowa Rail Corridor, LLC Iowa Northern Railway Company...) Docket No. FD 35507, North Central Iowa Rail Corridor, LLC--Acquisition Exemption--Union Pacific Railroad Company, in which North Central Iowa Rail Corridor, LLC seeks to acquire from Union Pacific Railroad...

78 FR 32007 - Environmental Impact Statement for Tulsa-Oklahoma City Passenger Rail Corridor, Oklahoma, Lincoln...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-28

... Environmental Policy Act of 1969 (NEPA) for the State of Oklahoma High-Speed Rail Initiative: Tulsa--Oklahoma... South Central High Speed Rail Corridor and is a federally-designated high-speed rail (HSR) corridor...-Speed Rail Initiative: Tulsa--Oklahoma City Passenger Rail Corridor Investment Plan. The proposed route...

The relationship of body size to survivorship of hatchling snapping turtles (Chelydra serpentina): an evaluation of the "bigger is better" hypothesis.

PubMed

Congdon, Justin D; Nagle, Roy D; Dunham, Arthur E; Beck, Chirstopher W; Kinney, Owen M; Yeomans, S Rebecca

1999-11-01

In many organisms, body size is positively correlated with traits that are presumably related to fitness. If directional selection frequently favors larger offspring (the "bigger is better" hypothesis), the results of such selection should be detectable with field experiments. We tested the "bigger is better" hypothesis in hatchling snapping turtles (Chelydra serpentina) by conducting one long-term and three short-term experiments on the University of Michigan E.S. George Reserve in southeastern Michigan. In the fall of 1995 and 1996, we released hatchlings at artificial nests separated from the nearest wetland by fences. We recorded the proportion of hatchlings recaptured, the time it took hatchlings to move to fences from artificial nests 45, 55, and 80 m away, and dispersion along the fence. We determined whether the response variables and probability of recapture at fences were associated with hatchling body size. During 1995, average travel times of hatchlings from the experimental nests were not related to distance from the fence; however, time to recapture was positively correlated with dispersion from the zero point on the fence, and the maximum time to reach the fence was almost twice as long for hatchlings from the 80-m nest compared to those from the 45-m nest. Sixty-seven percent of the hatchlings reached the fence and the proportions doing so from each nest were not different. Body size was not significantly related to probability of recapture in either of the 1995 experiments. In 1996, 59% of released hatchlings were recaptured. Time to recapture was not related to dispersion from the zero point or to body size. Cubic spline analysis suggested stabilizing selection on body size. We also conducted a set of long-term hatchling release experiments between 1980-1993 to compare the survival of hatchlings released at nest sites to that of hatchlings released directly into marshes, and we looked for relationships between survivorship and hatchling body size. During 7 years in which more than 30 hatchlings were released, 413 hatchlings were released directly into the marsh and 262 were released at nests: their probability of survival did not differ. Over all years, for both release groups combined and for each group separately, survival was not related to body size. In 1983 alone, survival was also not related to body size for either group or for both groups combined. In our three short-term experiments and one long-term experiment, we found no evidence to support the "bigger is better" hypothesis. When selection on body size did occur, selection was stabilizing, not directional for larger size.

Conservation value of remnant riparian forest corridors of varying quality for amazonian birds and mammals.

PubMed

Lees, Alexander C; Peres, Carlos A

2008-04-01

Forest corridors are often considered the main instrument with which to offset the effects of habitat loss and fragmentation. Brazilian forestry legislation requires that all riparian zones on private landholdings be maintained as permanent reserves and sets fixed minimum widths of riparian forest buffers to be retained alongside rivers and perennial streams. We investigated the effects of corridor width and degradation status of 37 riparian forest sites (including 24 corridors connected to large source-forest patches, 8 unconnected forest corridors, and 5 control riparian zones embedded within continuous forest patches) on bird and mammal species richness in a hyper-fragmented forest landscape surrounding Alta Floresta, Mato Grosso, Brazil. We used point-count and track-sampling methodology, coupled with an intensive forest-quality assessment that combined satellite imagery and ground truthed data. Vertebrate use of corridors was highly species-specific, but broad trends emerged depending on species life histories and their sensitivity to disturbance. Narrow and/or highly disturbed riparian corridors retained only a depauperate vertebrate assemblage that was typical of deforested habitats, whereas wide, well-preserved corridors retained a nearly complete species assemblage. Restriction of livestock movement along riparian buffers and their exclusion from key areas alongside deforested streams would permit corridor regeneration and facilitate restoration of connectivity.

Teaching Electric Fences: The Physics behind the Brainiac Video

ERIC Educational Resources Information Center

Vollmer, Michael

2016-01-01

In many states, electric fences are used to prevent animals from leaving a designated area, for example for grazing. They are quite well known by most students and can therefore serve as daily-life examples of electric circuits. Besides helping to grasp the ideas of Kirchhoff's laws for voltages and currents in circuits according to loop and…

Service life of fence posts treated by double-diffusion methods

Treesearch

Donald C. Markstrom; Lee R. Gjovik

1999-01-01

Service-life tests indicate that Engelmann spruce, lodgepole pine, and Rocky Mountain Douglas-fir fence posts treated by double-diffusion methods performed excellently after field exposure of 30 years with no failures. The test site was located in the semiarid Central Plains near Nunn, Colorado. Although Engelmann spruce posts generally defy treatment by other treating...

Expanding the Adoption on Private Lands : Blowing-and-Drifting Snow Control Treatments and the Cost Effectiveness of Permanent versus Non-Permanent Treatment Options

DOT National Transportation Integrated Search

2017-11-01

Previous research that estimated the costs and benefits of snow-fences for MnDOT in terms of a reduction in the costs of mitigating blowing-and-drifting snow problem areas (MN/RC 2012-03) demonstrated the ability of snow-fences to significantly lower...

Over the Fence: Learning about Education for Sustainability with New Tools and Conversation

ERIC Educational Resources Information Center

McClam, Sherie; Diefenbacher, Lori

2015-01-01

The metaphor of talking "over the fence" underscores the neutrality of tools. Shovels and hoes do the job, but the gardener creates the transformation of earth to food. Each garden requires a unique approach. Such are the tools of education for sustainable development (ESD). Pre-packaged textbooks and toolkits provide definitions and…

Installation Boundary Fence Replacement: Upland Areas: Environmental Assessment

DTIC Science & Technology

2004-05-27

Moody Air Force Base, GA Environmental Assessment Installation Boundary Fence Replacement INSTALLATION BOUNDARY...347 CES/CEV),3485 Georgia Street,Moody AFB, GA ,31699 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Moody Air Force Base, GA Environmental Assessment

Unified Facilities Criteria (UFC) Design Guide. Army Reserve Facilities

DTIC Science & Technology

2010-02-01

Laser ...Including Change 3, 1 February 2010 42 use. 3-2.3.1.8 Provide painted striping in POV and MEP areas, and elsewhere as needed. 3-2.3.2 Curb and Gutter...have to meet physical security requirements for security fencing. Most Tenants prefer that fences are located in a strip of rock mulch or

Ground-cover vegetation management at backcountry recreation sites

Treesearch

Stephen Fay

1975-01-01

Increasing use of remote backcountry recreation sites in the Northeast is resulting in a loss of the thin soil mantle and destruction of the ground-cover vegetation. Fencing, fertilization and liming and a combination of fencing, fertilization, and liming were tested as means of reestablishing ground-cover vegetation on bare mineral soils of the Tuckerman Ravine...

77 FR 25129 - Environmental Impact Statement for Issuance of a Special Use Permit for the Continued Operation...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-27

... covers Parking areas Three trap ranges, one skeet range, and a sporting clay course Skeet, trap, and sporting clay shot-fall zones Safety fences, barriers, and berms Permit area perimeter fences and signs... and pistol ranges, three trap ranges, one skeet range, and a sporting clay course, as listed above...

Protecting red oak seedlings with tree shelters in northwestern Pennsylvania

Treesearch

Russell S. Walters; Russell S. Walters

1993-01-01

Examines the growth and survival of planted and natural red oak seedlings and seedlings from planted acorns within translucent tan tree shelters, fences, and unprotected controls under a shelterwood seed-cut stand. Seedlings planted within tree shelters and fences were inside tree shelters. Natural seedlings grew very little and their height inside and outside of tree...

Effectiveness of Chain Link Turtle Fence and Culverts in Reducing Turtle Mortality and Providing Connectivity along U.S. Hwy 83, Valentine National Wildlife Refuge, Nebraska, USA

DOT National Transportation Integrated Search

2017-12-01

We evaluated the effectiveness of existing turtle fences through collecting and analyzing turtle mortality data along U.S. Hwy 83, in and around Valentine National Wildlife Refuge, Nebraska, USA. We also investigated the level of connectivity for tur...

75 FR 45695 - Final Federal Agency Actions on Trans-Texas Corridor 35 (TTC-35) in Texas

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-03

...-Texas Corridor 35 (TTC-35) in Texas AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice...-modal corridor to meet the transportation challenges of the I-35 corridor. EIS No. 20100133. The actions.... Land: Section 4(f) of the Department of Transportation Act of 1966 [49 U.S.C. 303]. 4. Wildlife...

75 FR 64741 - Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-20

... Corridor Commission: Notice of Meeting Notice is hereby given in accordance with Section 552b of Title 5... Corridor Commission will be held on Friday, November 19, 2010. The Commission was established pursuant to... Corridor. The meeting will convene on November 19, 2010 at 9 a.m. at Brigham Hill Community Barn located at...

75 FR 2885 - Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-19

... Corridor Commission: Notice of Meeting Notice is hereby given in accordance with Section 552b of Title 5... Corridor Commission will be held on Thursday, February 25, 2010. The Commission was established pursuant to... Corridor. The meeting will convene on February 25, 2010 at 9 a.m. at the Woonsocket City Hall located at...

14 CFR 93.81 - Applicability and description of area.

Code of Federal Regulations, 2011 CFR

2011-01-01

... as follows: (a) North-South Corridor. The North-South Corridor includes the airspace extending upward...°29′02″ N., Longitude 86°38′02″ W.; to point of beginning. (b) East-West Corridor—The East-West Corridor is divided into three sections to accommodate the different altitudes as portions of the corridor...

14 CFR 93.81 - Applicability and description of area.

Code of Federal Regulations, 2014 CFR

2014-01-01

... as follows: (a) North-South Corridor. The North-South Corridor includes the airspace extending upward...°29′02″ N., Longitude 86°38′02″ W.; to point of beginning. (b) East-West Corridor—The East-West Corridor is divided into three sections to accommodate the different altitudes as portions of the corridor...

14 CFR 93.81 - Applicability and description of area.

Code of Federal Regulations, 2013 CFR

2013-01-01

... as follows: (a) North-South Corridor. The North-South Corridor includes the airspace extending upward...°29′02″ N., Longitude 86°38′02″ W.; to point of beginning. (b) East-West Corridor—The East-West Corridor is divided into three sections to accommodate the different altitudes as portions of the corridor...

14 CFR 93.81 - Applicability and description of area.

Code of Federal Regulations, 2010 CFR

2010-01-01

... as follows: (a) North-South Corridor. The North-South Corridor includes the airspace extending upward...°29′02″ N., Longitude 86°38′02″ W.; to point of beginning. (b) East-West Corridor—The East-West Corridor is divided into three sections to accommodate the different altitudes as portions of the corridor...

14 CFR 93.81 - Applicability and description of area.

Code of Federal Regulations, 2012 CFR

2012-01-01

... as follows: (a) North-South Corridor. The North-South Corridor includes the airspace extending upward...°29′02″ N., Longitude 86°38′02″ W.; to point of beginning. (b) East-West Corridor—The East-West Corridor is divided into three sections to accommodate the different altitudes as portions of the corridor...

75 FR 48359 - Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-10

... Corridor Commission: Notice of Meeting Notice is hereby given in accordance with Section 552b of Title 5... Corridor Commission will be held on Thursday, September 16, 2010. The Commission was established pursuant... waters within the Corridor. The meeting will convene on September 16, 2010 at 9 a.m. at Slater Mill...

18. Readiness Crew Building interior, lower level corridor. This corridor ...

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

18. Readiness Crew Building interior, lower level corridor. This corridor is located in the southwest side of the building and runs from southeast to northwest; view looking northwest from the exit door at the southeast end. Lyon - Whiteman Air Force Base, Bomber Alert Facility S-6, 1300 Alert Road, Knob Noster, Johnson County, MO

78 FR 52602 - Notice To Rescind a Notice of Intent and Draft Environmental Impact Statement: I-17 Corridor...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-23

... and Draft Environmental Impact Statement: I-17 Corridor Improvement Study; Maricopa County, Arizona... Corridor Improvement Study was published in the Federal Register on January 6, 2010. FOR FURTHER... Corridor is located in the city of Phoenix, and the study area limits for the EIS consisted of...

Effects of weighting schemes on the identification of wildlife corridors generated with least-cost methods

Treesearch

Sean A. Parks; Kevin S. McKelvey; Michael K. Schwartz

2012-01-01

The importance of movement corridors for maintaining connectivity within metapopulations of wild animals is a cornerstone of conservation. One common approach for determining corridor locations is least-cost corridor (LCC) modeling, which uses algorithms within a geographic information system to search for routes with the lowest cumulative resistance between target...

Non-grazing and gophers lower bulk density and acidity in annual-plant soil

Treesearch

Raymond D. Ratliff; Stanley E. Westfall

1971-01-01

The effects of non-grazing on Ahwahnee coarse sandy loam were studied at the San Joaquin Experimental Range in central California. An exclosure, on which there had been no livestock grazing for 34 years, had a lower surface bulk density and lower acidity than an adjacent range that had been grazed. Bulk density averaged 1.08 gm./cc. on the ungrazed range, and 1.43 gm./...

Role of decaying logs and other organic seedbeds in natural regeneration of Hawaiian forest species on abandoned montane pasture

Treesearch

Paul G. Scowcroft

1992-01-01

Natural regeneration is one mechanism by which native mixed-species forests become reestablished on abandoned pasture. This study was done to determine patterns of and requirement for natural regeneration of native species in an open woodland after removal of cattle. Ten 50- by 50-m quadrats were randomly selected within a 16-ha exclosure located at 1,700-m elevation...

Critical dimensions of trans-sacral corridors assessed by 3D CT models: Relevance for implant positioning in fractures of the sacrum.

PubMed

Wagner, Daniel; Kamer, Lukas; Sawaguchi, Takeshi; Geoff Richards, R; Noser, Hansrudi; Uesugi, Masafumi; Ossendorf, Christian; Rommens, Pol M

2017-11-01

Trans-sacral implants can be used alternatively to sacro-iliac screws in the treatment of osteoporosis-associated fragility fractures of the pelvis and the sacrum. We investigated trans-sacral corridor dimensions, the number of individuals amenable to trans-sacral fixation, as well as the osseous boundaries and shape of the S1 corridor. 3D models were reconstructed from pelvic CT scans from 92 Europeans and 64 Japanese. A corridor of <12 mm was considered critical for trans-sacral implant positioning, and <8 mm as impossible. A statistical model of trans-sacral corridor S1 was computed. The limiting cranio-caudal diameter was 11.6 mm (±5.4) for S1 and 14 mm (±2.4) for S2. Trans-sacral implant positioning was critical in 52% of cases for S1, and in 21% for S2. The S1 corridor was impossible in 26%, with no impossible corridor in S2. Antero-superiorly, the S1 corridor was limited not only by the sacrum but in 40% by the iliac fossa. The statistical model demonstrated a consistent oval shape of the trans-section of corridor S1. Considering the variable in size and shape of trans-sacral corridors in S1, a thorough anatomical knowledge and preoperative planning are mandatory using trans-sacral implants. In critical cases, S2 is a veritable alternative. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2577-2584, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

CT scan based determination of optimal bone corridor for atlantoaxial ventral screw fixation in miniature breed dogs.

PubMed

Vizcaíno Revés, Núria; Stahl, Cristina; Stoffel, Michael; Bali, Monty; Forterre, Franck

2013-10-01

To describe the most reliable insertion angle, corridor length and width to place a ventral transarticular atlantoaxial screw in miniature breed dogs. Retrospective CT imaging study. Cervical CT scans of toy breed dogs (n = 21). Dogs were divided into 2 groups--group 1: no atlantoaxial abnormalities; group 2: atlantoaxial instability. Insertion angle in medial to lateral and ventral to dorsal direction was measured in group 1. Corridor length and width were measured in groups 1 and 2. Corridor width was measured at 3 points of the corridor. Each variable was measured 3 times and the mean used for statistical analysis. Mean ± SD optimal transarticular atlantoaxial insertion angle was determined to be 40 ± 1° in medial to lateral direction from the midline and 20 ± 1° in ventral to dorsal direction from the floor of the neural canal of C2. Mean corridor length was 7 mm (range, 4.5-8.0 mm). Significant correlation was found between corridor length, body weight, and age. Mean bone corridor width ranged from 3 to 5 mm. Statistically significant differences were found between individuals, gender and measured side. Optimal placement of a transarticular screw for atlantoaxial joint stabilization is very demanding because the screw path corridor is very narrow. © Copyright 2013 by The American College of Veterinary Surgeons.

75 FR 17756 - Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

... Corridor Commission: Notice of Meeting Notice is hereby given in accordance with Section 552b of Title 5... Corridor Commission will be held on Thursday, May 20, 2010. The Commission was established pursuant to... Corridor. The meeting will convene on May 20, 2010 at 9 a.m. at Atria Draper Place located at 25 Hopedale...

Mapping mountain torrent hazards in the Hexi Corridor using an evidential reasoning approach

NASA Astrophysics Data System (ADS)

Ran, Youhua; Liu, Jinpeng; Tian, Feng; Wang, Dekai

2017-02-01

The Hexi Corridor is an important part of the Silk Road Economic Belt and a crucial channel for westward development in China. Many important national engineering projects pass through the corridor, such as highways, railways, and the West-to-East Gas Pipeline. The frequent torrent disasters greatly impact the security of infrastructure and human safety. In this study, an evidential reasoning approach based on Dempster-Shafer theory is proposed for mapping mountain torrent hazards in the Hexi Corridor. A torrent hazard map for the Hexi Corridor was generated by integrating the driving factors of mountain torrent disasters including precipitation, terrain, flow concentration processes, and the vegetation fraction. The results show that the capability of the proposed method is satisfactory. The torrent hazard map shows that there is high potential torrent hazard in the central and southeastern Hexi Corridor. The results are useful for engineering planning support and resource protection in the Hexi Corridor. Further efforts are discussed for improving torrent hazard mapping and prediction.

Landscape corridors can increase invasion by an exotic species and reduce diversity of native species.

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

Resasco, Julian; et al,

2014-04-01

Abstract. Landscape corridors are commonly used to mitigate negative effects of habitat fragmentation, but concerns persist that they may facilitate the spread of invasive species. In a replicated landscape experiment of open habitat, we measured effects of corridors on the invasive fire ant, Solenopsis invicta, and native ants. Fire ants have two social forms: polygyne, which tend to disperse poorly but establish at high densities, and monogyne, which disperse widely but establish at lower densities. In landscapes dominated by polygyne fire ants, fire ant abundance was higher and native ant diversity was lower in habitat patches connected by corridors thanmore » in unconnected patches. Conversely, in landscapes dominated by monogyne fire ants, connectivity had no influence on fire ant abundance and native ant diversity. Polygyne fire ants dominated recently created landscapes, suggesting that these corridor effects may be transient. Our results suggest that corridors can facilitate invasion and they highlight the importance of considering species’ traits when assessing corridor utility.« less

Sex-specific differences of the infraacetabular corridor: a biomorphometric CT-based analysis on a database of 523 pelves.

PubMed

Gras, Florian; Gottschling, Heiko; Schröder, Manuel; Marintschev, Ivan; Reimers, Nils; Burgkart, Rainer

2015-01-01

An infraacetabular screw path facilitates the closure of a periacetabular fixation frame to increase the plate fixation strength in acetabular fractures up to 50%. Knowledge of the variance in corridor sizes and axes has substantial surgical relevance for safe screw placement. (1) What proportion of healthy pelvis specimens have an infraacetabular corridor that is 5 mm or larger in diameter? (2) Does a universal corridor axis and specific screw entry point exist? (3) Are there sex-specific differences in the infraacetabular corridor size or axis and are these correlated with anthropometric parameters like age, body weight and height, or the acetabular diameter? A template pelvis with a mean shape from 523 segmented pelvis specimens was generated using a CT-based advanced image analyzing system. Each individual pelvis was registered to the template using a free-form registration algorithm. Feasible surface regions for the entry and exit points of the infraacetabular corridor were marked on the template and automatically mapped to the individual samples to perform a measurement of the maximum sizes and axes of the infraacetabular corridor on each specimen. A minimum corridor diameter of at least 5 mm was defined as a cutoff for placing a 3.5-mm cortical screw in clinical settings. In 484 of 523 pelves (93%), an infraacetabular corridor with a diameter of at least 5 mm was found. Using the mean axis angulations (54.8° [95% confidence interval {CI}, 0.6] from anterocranial to posterocaudal in relation to the anterior pelvic plane and 1.5° [95% CI, 0.4] from anteromedial to posterolateral in relation to the sagittal midline plane), a sufficient osseous corridor was present in 64% of pelves. Allowing adjustment of the three-dimensional axis by another 5° included an additional 25% of pelves. All corridor parameters were different between females and males (corridor diameter, 6.9 [95% CI, 0.2] versus 7.7 [95% CI, 0.2] mm; p<0.001; corridor length, 96.2 [95% CI, 0.7] versus 106.4 [95% CI, 0.6] mm; p<0.001; anterior pelvic plane angle, 54.0° [95% CI, 0.9] versus 55.3° [95% CI, 0.8]; p<0.01; sagittal midline plane angle, 4.3° [95% CI, 0.6] versus -0.3° [95% CI, 0.5]; p<0.001). This study provided reference values for placement of a 3.5-mm cortical screw in the infraacetabular osseous corridor in 90% of female and 94% of male pelves. Based on the sex-related differences in corridor axes, the mean screw trajectory is approximately parallel to the sagittal midline plane in males but has to be tilted from medial to lateral in females. Considering the narrow corridor diameters, we suggest an individual preoperative CT scan analysis for fine adjustments in each patient.

Environmental Assessment of Construction of Antenna Parts Storage Facility, Upgrade of Perimeter Security Fence, Demolition of Storage Shed, Hawkinsville Air Force Space Surveillance Station, Hawkinsville, Georgia

DTIC Science & Technology

2012-11-01

the most common. Japanese honeysuckle and Chinese tallow are limited to are- as along the fence line, and mimosa was only found in two locations at the...HAWKINSVILLE AFSSS Scientific Name Common Name Albizia julibrissin* mimosa Ampelopsis arborea peppervine Andropogon virginicus broomsedge bluestem

Aspen fencing in northern Arizona: A 15-year perspective

Treesearch

James M. Rolf

2001-01-01

Aspen clearcuts in the 1960s and 1970s on the Peaks Ranger District of the Coconino National Forest in northern Arizona failed to regenerate successfully because of browsing primarily by elk. Since 1985, over 400 acres have been successfully regenerated using fencing of various designs to exclude elk. The expense and visual impact of establishing and maintaining over...

Reestablishing understory plants in overused wooded areas of Maryland state parks

Treesearch

Silas Little; John J. Mohr

1979-01-01

In four overused areas, the treatments of small plots were fencing, scarifying the soil, and mulching; fencing and mulching plus planting of shrubs, herbaceous plants, or greenbrier with shrubs or holly. After 3 years, soil compaction was two to four times as great in check plots as in treated plots. Understory cover varied with conditions, but because of volunteer...

Advanced Oak Seedling Development as Influenced by Shelterwood Treatments, Competition Control, Deer Fencing, and Prescribed Fire

Treesearch

Gary W. Miller; Patrick H. Brose; Kurt W. Gottschalk

2017-01-01

Advanced northern red oak (Quercus rubra) seedlings in an 85-year-old forest located in north-central Pennsylvania were observed for 10 years after manipulation of available sunlight by shelterwood treatments, reduction of interfering plants by broadcast herbicides and/or a single prescribed fire, and reduction of deer damage by fencing. Twenty-...

Effect of deer browsing on timber production in Allegheny hardwood forests of Northwestern Pennsylvania

Treesearch

David A. Marquis

1981-01-01

Regeneration surveys in fenced and unfenced portions of thirteen 9- to 22-year-old clearcuts on the Allegheny Plateauof Northwestern Pennsylvania show that deer browsing has resulted in (a) inadequate stocking of tree species, (b) delay in establishment, and (c) less valuable species composition. Ninety-two percent of the fenced areas, but only 38 percent of the...

Stem quality of oak in 15-year-old stands: influence of species within harvesting treatment and fencing

Treesearch

Kurt W. Gottschalk

1997-01-01

The effect of harvesting treatment, fencing, and species on the stem quality of oak (Quercus spp.) was evaluated in mixed-hardwood stands on the Allegheny Plateau in central Pennsylvania. The regeneration harvests included commercial clearcut that removed most stems ≥ 15 cm dbh and a clearcut with timber stand improvement (TSI) that removed...

An Efficient Bifunctional Electrocatalyst for a Zinc-Air Battery Derived from Fe/N/C and Bimetallic Metal-Organic Framework Composites.

PubMed

Wang, Mengfan; Qian, Tao; Zhou, Jinqiu; Yan, Chenglin

2017-02-15

Efficient bifunctional electrocatalysts with desirable oxygen activities are closely related to practical applications of renewable energy systems including metal-air batteries, fuel cells, and water splitting. Here a composite material derived from a combination of bimetallic zeolitic imidazolate frameworks (denoted as BMZIFs) and Fe/N/C framework was reported as an efficient bifunctional catalyst. Although BMZIF or Fe/N/C alone exhibits undesirable oxygen reaction activity, a combination of these materials shows unprecedented ORR (half-wave potential of 0.85 V as well as comparatively superior OER activities (potential@10 mA cm -2 of 1.64 V), outperforming not only a commercial Pt/C electrocatalyst but also most reported bifunctional electrocatalysts. We then tested its practical application in Zn-air batteries. The primary batteries exhibit a high peak power density of 235 mW cm -2 , and the batteries are able to be operated smoothly for 100 cycles at a curent density of 10 mA cm -2 . The unprecedented catalytic activity can be attritued to chemical coupling effects between Fe/N/C and BMZIF and will aid the development of highly active electrocatalysts and applications for electrochemical energy devices.

Sparse intervertebral fence composition for 3D cervical vertebra segmentation

NASA Astrophysics Data System (ADS)

Liu, Xinxin; Yang, Jian; Song, Shuang; Cong, Weijian; Jiao, Peifeng; Song, Hong; Ai, Danni; Jiang, Yurong; Wang, Yongtian

2018-06-01

Statistical shape models are capable of extracting shape prior information, and are usually utilized to assist the task of segmentation of medical images. However, such models require large training datasets in the case of multi-object structures, and it also is difficult to achieve satisfactory results for complex shapes. This study proposed a novel statistical model for cervical vertebra segmentation, called sparse intervertebral fence composition (SiFC), which can reconstruct the boundary between adjacent vertebrae by modeling intervertebral fences. The complex shape of the cervical spine is replaced by a simple intervertebral fence, which considerably reduces the difficulty of cervical segmentation. The final segmentation results are obtained by using a 3D active contour deformation model without shape constraint, which substantially enhances the recognition capability of the proposed method for objects with complex shapes. The proposed segmentation framework is tested on a dataset with CT images from 20 patients. A quantitative comparison against corresponding reference vertebral segmentation yields an overall mean absolute surface distance of 0.70 mm and a dice similarity index of 95.47% for cervical vertebral segmentation. The experimental results show that the SiFC method achieves competitive cervical vertebral segmentation performances, and completely eliminates inter-process overlap.

Integrated corridor management : ICM implementation guide

DOT National Transportation Integrated Search

2006-04-12

This Implementation Guidance for Integrated Corridor Management (ICM) has been developed as part of Phase 1 (Foundational Research) for the Federal Highway Administration and the Federal Transit Administration Integrated Corridor Management Initiativ...

Comprehensive highway corridor planning with sustainability indicators.

DOT National Transportation Integrated Search

2011-10-01

"The Maryland State Highway Administration (SHA) has initiated major planning efforts to improve transportation : efficiency, safety, and sustainability on critical highway corridors through its Comprehensive Highway Corridor : (CHC) program. This pr...

Comprehensive highway corridor planning with sustainability indicators.

DOT National Transportation Integrated Search

2013-04-01

The Maryland State Highway Administration (SHA) has initiated major planning efforts to improve transportation : efficiency, safety, and sustainability on critical highway corridors through its Comprehensive Highway Corridor : (CHC) program. This pro...

75 FR 22758 - Intent To Prepare a Draft Environmental Impact Statement for Improvements to the U.S. 17 and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-30

... Environmental Impact Statement for Improvements to the U.S. 17 and Market Street (U.S. 17 Business) Corridor in... and Market Street (U.S. 17 Business) corridor in northern New Hanover and southern Pender Counties... are being evaluated as part of the U.S. 17 Corridor Study. The purpose of the U.S. 17 Corridor Study...

77 FR 74729 - Notice To Rescind a Notice of Intent and Draft Environmental Impact Statement: I-10 Corridor...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-17

... and Draft Environmental Impact Statement: I-10 Corridor Improvement Study; Maricopa County, AZ AGENCY..., Arizona. A NOI to prepare an EIS for the I-10 Corridor Improvement Study was published in the Federal..., Arizona. The I-10 Corridor is in or adjacent to the cities of Phoenix, Tempe, and Chandler, as well as the...

Uncertainty analysis of least-cost modeling for designing wildlife linkages.

PubMed

Beier, Paul; Majka, Daniel R; Newell, Shawn L

2009-12-01

Least-cost models for focal species are widely used to design wildlife corridors. To evaluate the least-cost modeling approach used to develop 15 linkage designs in southern California, USA, we assessed robustness of the largest and least constrained linkage. Species experts parameterized models for eight species with weights for four habitat factors (land cover, topographic position, elevation, road density) and resistance values for each class within a factor (e.g., each class of land cover). Each model produced a proposed corridor for that species. We examined the extent to which uncertainty in factor weights and class resistance values affected two key conservation-relevant outputs, namely, the location and modeled resistance to movement of each proposed corridor. To do so, we compared the proposed corridor to 13 alternative corridors created with parameter sets that spanned the plausible ranges of biological uncertainty in these parameters. Models for five species were highly robust (mean overlap 88%, little or no increase in resistance). Although the proposed corridors for the other three focal species overlapped as little as 0% (mean 58%) of the alternative corridors, resistance in the proposed corridors for these three species was rarely higher than resistance in the alternative corridors (mean difference was 0.025 on a scale of 1 10; worst difference was 0.39). As long as the model had the correct rank order of resistance values and factor weights, our results suggest that the predicted corridor is robust to uncertainty. The three carnivore focal species, alone or in combination, were not effective umbrellas for the other focal species. The carnivore corridors failed to overlap the predicted corridors of most other focal species and provided relatively high resistance for the other focal species (mean increase of 2.7 resistance units). Least-cost modelers should conduct uncertainty analysis so that decision-makers can appreciate the potential impact of model uncertainty on conservation decisions. Our approach to uncertainty analysis (which can be called a worst-case scenario approach) is appropriate for complex models in which distribution of the input parameters cannot be specified.

Predicting the continuum between corridors and barriers to animal movements using Step Selection Functions and Randomized Shortest Paths.

PubMed

Panzacchi, Manuela; Van Moorter, Bram; Strand, Olav; Saerens, Marco; Kivimäki, Ilkka; St Clair, Colleen C; Herfindal, Ivar; Boitani, Luigi

2016-01-01

The loss, fragmentation and degradation of habitat everywhere on Earth prompts increasing attention to identifying landscape features that support animal movement (corridors) or impedes it (barriers). Most algorithms used to predict corridors assume that animals move through preferred habitat either optimally (e.g. least cost path) or as random walkers (e.g. current models), but neither extreme is realistic. We propose that corridors and barriers are two sides of the same coin and that animals experience landscapes as spatiotemporally dynamic corridor-barrier continua connecting (separating) functional areas where individuals fulfil specific ecological processes. Based on this conceptual framework, we propose a novel methodological approach that uses high-resolution individual-based movement data to predict corridor-barrier continua with increased realism. Our approach consists of two innovations. First, we use step selection functions (SSF) to predict friction maps quantifying corridor-barrier continua for tactical steps between consecutive locations. Secondly, we introduce to movement ecology the randomized shortest path algorithm (RSP) which operates on friction maps to predict the corridor-barrier continuum for strategic movements between functional areas. By modulating the parameter Ѳ, which controls the trade-off between exploration and optimal exploitation of the environment, RSP bridges the gap between algorithms assuming optimal movements (when Ѳ approaches infinity, RSP is equivalent to LCP) or random walk (when Ѳ → 0, RSP → current models). Using this approach, we identify migration corridors for GPS-monitored wild reindeer (Rangifer t. tarandus) in Norway. We demonstrate that reindeer movement is best predicted by an intermediate value of Ѳ, indicative of a movement trade-off between optimization and exploration. Model calibration allows identification of a corridor-barrier continuum that closely fits empirical data and demonstrates that RSP outperforms models that assume either optimality or random walk. The proposed approach models the multiscale cognitive maps by which animals likely navigate real landscapes and generalizes the most common algorithms for identifying corridors. Because suboptimal, but non-random, movement strategies are likely widespread, our approach has the potential to predict more realistic corridor-barrier continua for a wide range of species. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Transition Induced by Fence Geometrics on Shuttle Orbiter at Mach 10

NASA Technical Reports Server (NTRS)

Everhart, Joel L.

2010-01-01

Fence-induced transition data simulating a raised gap filler have been acquired on the wing lower surface of a Shuttle Orbiter model in the Langley 31-Inch Mach 10 Tunnel to compare with the Shuttle Boundary Layer Transition Flight and HYTHIRM Experiments, and to provide additional correlation data for the Boundary Layer Transition Tool. In a qualitative assessment, the data exhibit the expected response to all parameter variations; however, it is unclear whether fully effective tripping at the fence was ever realized at any test condition with the present model hardware. A preliminary, qualitative comparison of the ground-based transition measurements with those obtained from the STS-128 HYTHIRM imagery at Mach 15 reveal similar transition-wake response characteristics in terms of the spreading and the path along the vehicle surface.

INTERIOR VIEW, EASTWEST CORRIDOR SEEN THROUGH EAST SIDE ENTRY (NOTE ...

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

INTERIOR VIEW, EAST-WEST CORRIDOR SEEN THROUGH EAST SIDE ENTRY (NOTE GLASS BLOCK TRANSOM PROVIDING LIGHT INTO CORRIDOR) - Greenbelt Community Building, 15 Crescent Road, Greenbelt, Prince George's County, MD

Effective strategies for comprehensive corridor management

DOT National Transportation Integrated Search

2004-10-01

Despite the increasing importance of comprehensive corridor management at the state and local government level, questions remain regarding effective methods for developing and implementing corridor management plans. Further insight is also needed int...

78 FR 23815 - Northeast Corridor Safety Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-22

.... 6] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of the Northeast Corridor Safety Committee (NECSC) Meeting. [[Page 23816

Evaluating the intersection of a regional wildlife connectivity network with highways.

PubMed

Cushman, Samuel A; Lewis, Jesse S; Landguth, Erin L

2013-01-01

Reliable predictions of regional-scale population connectivity are needed to prioritize conservation actions. However, there have been few examples of regional connectivity models that are empirically derived and validated. The central goals of this paper were to (1) evaluate the effectiveness of factorial least cost path corridor mapping on an empirical resistance surface in reflecting the frequency of highway crossings by American black bear, (2) predict the location and predicted intensity of use of movement corridors for American black bear, and (3) identify where these corridors cross major highways and rank the intensity of these crossings. We used factorial least cost path modeling coupled with resistant kernel analysis to predict a network of movement corridors across a 30.2 million hectare analysis area in Montana and Idaho, USA. Factorial least cost path corridor mapping was associated with the locations of actual bear highway crossings. We identified corridor-highway intersections and ranked these based on corridor strength. We found that a major wildlife crossing overpass structure was located close to one of the most intense predicted corridors, and that the vast majority of the predicted corridor network was "protected" under federal management. However, narrow, linear corridors connecting the Greater Yellowstone Ecosystem to the rest of the analysis area had limited protection by federal ownership, making these additionally vulnerable to habitat loss and fragmentation. Factorial least cost path modeling coupled with resistant kernel analysis provides detailed, synoptic information about connectivity across populations that vary in distribution and density in complex landscapes. Specifically, our results could be used to quantify the structure of the connectivity network, identify critical linkage nodes and core areas, map potential barriers and fracture zones, and prioritize locations for mitigation, restoration and conservation actions.

Energy Futures Synthesis for West-Wide Section 368 Energy Corridors

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

O'Neill, Barbara L.; Gagne, Douglas A.; Cook, Jeffrey J.

To comply with Section 368(a) of the Energy Policy Act of 2005 (EPAct), the U.S. Bureau of Land Management (BLM) and the U.S. Forest Service designated 6,000 miles of energy corridors on public and national forest lands in the western United States in 2009. The corridors, commonly referred to as 'West-wide' or 'Section 368' energy corridors, are intended as preferred locations for future siting of electric transmission and distribution lines and for oil, gas, and hydrogen pipelines. In response to a lawsuit filed by several organizations over the corridor designations, the BLM, Forest Service, and the U.S. Department of Energymore » entered into a Settlement Agreement, directing the formation of the Section 368 Interagency Workgroup to periodically review the energy corridors on a regional basis. In conducting the reviews, the Workgroup identifies new, relevant, existing, publicly available information to make recommendations for revisions, deletions, and additions to the Section 368 energy corridors. This report synthesizes information in available contemporary transmission, pipeline, and energy future studies to inform the regional reviews by providing a snapshot of what the western energy and transmission system will look like generally 10-15 years in the future. After an overview of the western grid implications, the analysis narrows to Region 2 and Region 3 of the BLM Section 368 energy corridors and focuses on the implications of potential developments in the oil, natural gas, and electricity markets in Colorado, New Mexico, Utah, and portions of Arizona and Nevada that could inform the current regional review. This analysis will help inform the Workgroup on potential development within existing corridors and the need for new corridors that have not yet been designated.« less

43 CFR 2802.11 - How does BLM designate corridors?

Code of Federal Regulations, 2014 CFR

2014-10-01

... activities located within the proposed right-of-way corridor; (7) Social and economic impacts of the right-of...) Transportation and utility corridor studies previously developed by user groups; and (9) Engineering and...

14 CFR 93.319 - Commercial air tour limitations.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., as applicable: (1) Total SFRA allocations; and (2) Dragon corridor and Zuni Point corridor... minutes east. This exception does not include operation in the Zuni Point corridor. [65 FR 17732, Apr. 4...

North side, enclosed corridor connecting buildings 511 and 515. West ...

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

North side, enclosed corridor connecting buildings 511 and 515. West side of corridor. - Fitzsimons General Hospital, Infirmary, Northwest Corner of East Bushnell Avenue & South Page Street, Aurora, Adams County, CO

Comprehensive highway corridor planning with sustainability indicators : [research summary].

DOT National Transportation Integrated Search

2013-04-01

The Maryland State Highway Administration (SHA) has initiated major planning : efforts to improve transportation efficiency, safety and sustainability on critical : highway corridors through its Comprehensive Highway Corridor (CHC) program. : It is i...

Corridor incident management (CIM)

DOT National Transportation Integrated Search

2007-09-01

The objective of the Corridor Incident Management (CIM) research project was to develop and demonstrate a set of multi-purpose methods, tools and databases to improve corridor incident management in Tennessee, relying primarily on resources already a...

Multimodal corridor and capacity analysis manual. Final report

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

NONE

1998-12-31

This report presents the results of research carried out under NCHRP Project 8-31, Long-Term Availability of Multimodal Corridor Capacity. The report is presented as a manual on multimodal corridor and capacity analysis. Because transportation-system and corridor capacity for freight and passengers is critical for meeting current and future transportation demand, this manual will provide much needed assistance to a wide range of practitioners, particularly those engaged in performance analysis, capacity management, needs studies, systems planning, and corridor development planning--including major investment studies. It provides information regarding capacity analysis approaches for highways, rail, pipelines, and waterways and presents available options formore » enhancing corridor capacity and performance through various strategies such as new capacity development, freeing up unused capacity, or control of travel demand. Evaluation methods for these options are included.« less

Effect of course length and corridor width on the 2-minute walk test performance in geriatric patients.

PubMed

Lindemann, Ulrich; Beck, Luisa; Becker, Clemens

2017-02-01

To evaluate the effect of course length and corridor width on 2-minute walk test results in older adults. Cross-sectional and experimental study with different test conditions. Geriatric rehabilitation clinic. A total of 21 patients (median age 81 years). Patients walked two minutes on a 20 m and 40 m course with a 2 m or 1 m corridor width and on a continuous course without any turning in a corridor of 2 m width, five walks in total. The distance traveled within the 2 minutes was recorded. Compared with the 20 m course length, median walking distances measured by the 2-minute walk test in a walk way 2 m broad were better on the continuous corridor without any turn (136.9 m vs. 129.3 m, p = 0.002) and on the 40 m course (131.8 m vs. 129.3 m, p = 0.003). Walking distance on a 20 m course length was longer in a corridor of 2 m width compared with the 1 m corridor width (129.3 m vs. 119.2 m, p = 0.005). The walking distance was not affected by corridor width on the 40 m course length. Performance of elderly patients on the 2-minute walk test is influenced by the width of the corridor and the length of the course used.

"Everything Happens in the Hallways": Exploring User Activity in the Corridors at Two Rehabilitation Units.

PubMed

Colley, Jacinta; Zeeman, Heidi; Kendall, Elizabeth

2017-01-01

This research aimed to examine the role of the corridors in specialist inpatient rehabilitation units to inform future design of these spaces. In healthcare settings, such as rehabilitation units, corridors have often been designed simply as spaces allowing movement between other locations. However, research suggests that corridors may be places where important social and care-related activities take place. How corridors are used and understood by patients and staff in inpatient rehabilitation settings is unclear, and a greater understanding of the role of corridors in these settings could help to inform more supportive design of these spaces. Independent observations of user activity were conducted at a major metropolitan inpatient spinal injury unit (SIU) and brain injury unit (BIU). Interviews were conducted with SIU patients ( n = 12), and focus groups were conducted with SIU staff ( n = 23), BIU patients ( n = 12), and BIU staff ( n = 10). Results from the observations showed that the corridors were used frequently across the day, particularly by staff. Thematic analysis of staff and patient experiences found three key themes describing how corridors were used: (1) moving around, (2) delivery and experiences of quality care, and (3) a "spillover space." Results demonstrate that corridors not only have an important role as connective spaces but are also used as flexible, multipurpose spaces for delivery of quality care and patient experiences. Future design should consider how these spaces can more deliberately support and contribute to patient and staff experiences of rehabilitation.

China Pakistan Economic Corridor (CPEC): Challenges and the Way Forward

DTIC Science & Technology

2017-06-01

ECONOMIC CORRIDOR (CPEC): CHALLENGES AND THE WAY FORWARD by Muzaffar Hussain June 2017 Thesis Advisor: Robert E. Looney Second Reader...DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE CHINA PAKISTAN ECONOMIC CORRIDOR (CPEC): CHALLENGES AND THE WAY FORWARD 5. FUNDING NUMBERS...is unlimited. 12b. DISTRIBUTION CODE 13. ABSTRACT The China-Pakistan Economic Corridor (CPEC)—the latest venture in a history of bilateral economic

23 CFR Appendix C to Subpart A of... - Policy for the Signing and Numbering of Future Interstate Corridors Designated by Section 332 of...

Code of Federal Regulations, 2014 CFR

2014-04-01

... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... signs along a federally designated future Interstate corridor only after the specific route location has...

23 CFR Appendix C to Subpart A of... - Policy for the Signing and Numbering of Future Interstate Corridors Designated by Section 332 of...

Code of Federal Regulations, 2011 CFR

2011-04-01

... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... signs along a federally designated future Interstate corridor only after the specific route location has...

23 CFR Appendix C to Subpart A of... - Policy for the Signing and Numbering of Future Interstate Corridors Designated by Section 332 of...

Code of Federal Regulations, 2013 CFR

2013-04-01

... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... signs along a federally designated future Interstate corridor only after the specific route location has...

23 CFR Appendix C to Subpart A of... - Policy for the Signing and Numbering of Future Interstate Corridors Designated by Section 332 of...

Code of Federal Regulations, 2010 CFR

2010-04-01

... Interstate Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S... Corridors Designated by Section 332 of the NHS Designation Act of 1995 or Designated Under 23 U.S.C. 139(b... federally designated future Interstate corridor only after the specific route location has been established...

Corridors cause differential seed predation.

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

Orrock, John L.; Damschen, Ellen I.

2005-06-01

Orrock, John, L., and Ellen I. Damschen. 2005. Corridors cause differential seed predation. Ecol. Apps. 15(3):793-798. Abstract. Corridors that connect disjunct populations are heavily debated in conservation, largely because the effects of corridors have rarely been evaluated by replicated, large-scale studies. Using large-scale experimental landscapes, we found that, in addition to documented positive effects, corridors also have negative impacts on bird-dispersed plants by affecting seed predation, and that overall predation is a function of the seeds primary consumer (rodents or arthropods). Both large-seeded Prunus serotina and small-seeded Rubus allegheniensis experienced greater predation in connected patches. However, P. serotina experienced significantlymore » less seed predation compared to R. allegheniensis in unconnected patches, due to decreased impacts of rodent seed predators on this large-seeded species. Viewed in light of previous evidence that corridors have beneficial impacts by increasing pollination and seed dispersal, this work demonstrates that corridors may have both positive and negative effects for the same plant species at different life stages. Moreover, these effects may differentially affect plant species within the same community: seeds primarily consumed by rodents suffer less predation in unconnected patches. By shifting the impact of rodent and arthropod seed predators, corridors constructed for plant conservation could lead to shifts in the seed bank.« less

An introduction to issues of habitat fragmentation relative to transportation corridors with special reference to high-speed rail (HSR)

NASA Astrophysics Data System (ADS)

de Santo, Robert S.; Smith, Dwight G.

1993-01-01

Potential environmental impacts on wildlife result from siting and construction (short-term impacts) and habitat removal and fragmentation (long-term impacts) as a consequence of transportation corridor construction. Especially in rural districts, wildlife migration corridors and dispersal orientation are altered or destroyed and wildlife populations and their gene pools are isolated. This significantly weakens the wildlife community. Prudent selection of construction corridors reduces fragmentation impacts by maximizing preserved fragment sizes, and by running parallel to, not through, natural areas. Corridor width determines the degree to which wildlife movement is restricted except that culverts, underpasses, overpasses, and one-way gates, can aid wildlife in cross movements. Minimum underpass dimensions for large wildlife should be no smaller than 14 ft×14 ft and should include natural substratum inverts. Rail corridors have four characteristics that minimize adverse environmental impacts. The railbed is dry, ballast fillters runoff, there is little runoff beyond the toe of slope, and drainage ditches serve to control sheet flow and erosion, sediment movement, and uncontrolled channel flow. Rail corridors usually occupy smaller land areas because they are narrower and are more feasible to elevate so as to allow free movement of wildlife across the corridor.

Identifying transit corridors for elephant using a long time-series

NASA Astrophysics Data System (ADS)

Pittiglio, Claudia; Skidmore, Andrew K.; van Gils, Hein A. M. J.; Prins, Herbert H. T.

2012-02-01

The role of corridors in mitigating the effects of landscape fragmentation on biodiversity is controversial. Recent studies have highlighted the need for new approaches in corridor design using long-term datasets. We present a method to identify transit corridors for elephant at a population scale over a large area and an extended period of time using long-term aerial surveys. We investigated environmental and anthropogenic factors directly and indirectly related to the wet versus dry season distribution of elephant and its transit corridors. Four environmental variables predicted the presence of elephant at the landscape scale in both seasons: distance from permanent water, protected areas and settlements and vegetation structure. Path analysis revealed that altitude and monthly average NDVI, and distance from temporary water had a significant indirect effect on elephant distribution at local scale in dry and wet seasons respectively. Five transit corridors connecting Tarangire National Park and the northern as well as south-eastern wet season dispersal areas were identified and matched the wildlife migration routes described in the 1960s. The corridors are stable over the decades, providing landscape connectivity for elephant. Our approach yielded insights how advanced spatial analysis can be integrated with biological data available from long-term datasets to identify actual transit corridors and predictors of species distribution.

The role of green corridors for wildlife conservation in urban landscape: A literature review

NASA Astrophysics Data System (ADS)

Aziz, H. A.; Rasidi, M. H.

2014-02-01

Green corridors are an attempt to mitigate negative effects of the built environment of cities and towns. The corridors act as conservation for rapidly extreme intervention and development of the urban environment. Most importantly, it enables dispersal movement of animals within city areas. Issues relate to wildlife conservation in urban areas has been studied for many years and thus, the research makes a review for how the green corridors contribute to the conservation of urban wildlife. This study reviews groups of articles in disciplines of urban landscape planning and biology conservation to discuss the relationship between elements of green corridors and urban wildlife dispersal movement behaviour in Malaysian context. Accordingly, this research is purposely studied to give understanding on how green corridors contribute to the animals' ability of moving and dispersing within the built-up areas. In advance, it is found that there are three factors contribute to the capability of colonization among urban wildlife which are individual, physical and social factor. Green corridor has been defined as one of the physical factor that influence urban wildlife behaviour movement. Consequently, safety area indicating to animals species for traversing in any time such as at night can be defined as the primary potential corridor.

Maglev guideway route alignment and right-of-way requirements

NASA Astrophysics Data System (ADS)

Carlton, S.; Andriola, T.

1992-12-01

The use of existing rights-of-way (ROW) is assessed for maglev systems by estimating trip times and land acquisition requirements for potential maglev corridors while meeting passenger comfort limits. Right-of-way excursions improve trip time but incur a cost for purchasing land. The final report documents findings of the eight tasks in establishing right-of-way feasibility by examining three city-pair corridors in detail and developing an approximation method for estimating route length and travel times in 20 additional city-pair corridor portions and 21 new corridors. The use of routes independent of existing railroad or highway right-of-way have trip time advantages and significantly reduce the need for aggressive guideway geometries on intercity corridors. Selection of the appropriate alignment is determined by many corridor specific issues. Use of existing intercity rights-of-way may be appropriate for parts of routes on a corridor-specific basis and for urban penetration where vehicle speeds are likely to be reduced by policy due to noise and safety considerations, and where land acquisition costs are high. Detailed aspects of available rights-of-way, land acquisition costs, geotechnical issues, land use, and population centers must be examined in more detail on a specific corridor basis before the proper or best maglev alignment can be chosen.

The potential of electricity transmission corridors in forested areas as bumblebee habitat.

PubMed

Hill, Bruce; Bartomeus, Ignasi

2016-11-01

Declines in pollinator abundance and diversity are not only a conservation issue, but also a threat to crop pollination. Maintained infrastructure corridors, such as those containing electricity transmission lines, are potentially important wild pollinator habitat. However, there is a lack of evidence comparing the abundance and diversity of wild pollinators in transmission corridors with other important pollinator habitats. We compared the diversity of a key pollinator group, bumblebees ( Bombus spp.), between transmission corridors and the surrounding semi-natural and managed habitat types at 10 sites across Sweden's Uppland region. Our results show that transmission corridors have no impact on bumblebee diversity in the surrounding area. However, transmission corridors and other maintained habitats such as roadsides have a level of bumblebee abundance and diversity comparable to semi-natural grasslands and host species that are important for conservation and ecosystem service provision. Under the current management regime, transmission corridors already provide valuable bumblebee habitat, but given that host plant density is the main determinant of bumblebee abundance, these areas could potentially be enhanced by establishing and maintaining key host plants. We show that in northern temperate regions the maintenance of transmission corridors has the potential to contribute to bumblebee conservation and the ecosystem services they provide.

The potential of electricity transmission corridors in forested areas as bumblebee habitat

PubMed Central

Hill, Bruce

2016-01-01

Declines in pollinator abundance and diversity are not only a conservation issue, but also a threat to crop pollination. Maintained infrastructure corridors, such as those containing electricity transmission lines, are potentially important wild pollinator habitat. However, there is a lack of evidence comparing the abundance and diversity of wild pollinators in transmission corridors with other important pollinator habitats. We compared the diversity of a key pollinator group, bumblebees (Bombus spp.), between transmission corridors and the surrounding semi-natural and managed habitat types at 10 sites across Sweden's Uppland region. Our results show that transmission corridors have no impact on bumblebee diversity in the surrounding area. However, transmission corridors and other maintained habitats such as roadsides have a level of bumblebee abundance and diversity comparable to semi-natural grasslands and host species that are important for conservation and ecosystem service provision. Under the current management regime, transmission corridors already provide valuable bumblebee habitat, but given that host plant density is the main determinant of bumblebee abundance, these areas could potentially be enhanced by establishing and maintaining key host plants. We show that in northern temperate regions the maintenance of transmission corridors has the potential to contribute to bumblebee conservation and the ecosystem services they provide. PMID:28018640

The role of corridors in conservation: Solution or bandwagon?

PubMed

Hobbs, R J

1992-11-01

Corridors are currently a major buzzword in conservation biology and landscape ecology. These linear landscape features may perform numerous functions, but it is their role in facilitating movement of fauna that has attracted much recent debate. The database supporting the idea of corridors acting as faunal conduits is remarkably small, and few studies have actually demonstrated that movement along corridors is important for any given species. Such data are very difficult to obtain, and conservation biologists are thus faced with the problem of whether to recommend the allocation of resources to corridors on the assumption that they may be important. Copyright © 1992. Published by Elsevier Ltd.

Magellan aerobraking periapse corridor design

NASA Technical Reports Server (NTRS)

Cook, Richard A.; Lyons, Daniel T.

1992-01-01

One extended mission idea for the Magellan project uses aerobraking techniques to circularize the current orbit. A major technical issue in this proposal is the design of the periapse altitude corridor. Aerobraking would cause a number of significant side effects on both the spacecraft and ground system. Heating and aerodynamic torques on the spacecraft are key issues, as are the corridor control maneuver frequency and aerobrake duration. Spacecraft and ground systems operational limits have been identified in an attempt to constrain the corridor design. A simulation program has been developed to model the aerobraking corridor control process. This paper presents study results using this program which relate to the feasibility of this aerobraking concept.

Transsacral Osseous Corridor Anatomy Is More Amenable To Screw Insertion In Males: A Biomorphometric Analysis of 280 Pelves.

PubMed

Gras, Florian; Gottschling, Heiko; Schröder, Manuel; Marintschev, Ivan; Hofmann, Gunther O; Burgkart, Rainer

2016-10-01

Percutaneous iliosacral screw placement is the standard procedure for fixation of posterior pelvic ring lesions, although a transsacral screw path is being used more frequently in recent years owing to increased fracture-fixation strength and better ability to fix central and bilateral sacral fractures. However, biomorphometric data for the osseous corridors are limited. Because placement of these screws in a safe and effective manner is crucial to using transsacral screws, we sought to address precise sacral anatomy in more detail to look for anatomic variation in the general population. We asked: (1) What proportion of healthy pelvis specimens have no transsacral corridor at the level of the S1 vertebra owing to sacral dysmorphism? (2) If there is no safe diameter for screw placement in the transsacral S1 corridor, is an increased and thus safe diameter of the transsacral S2 corridor expected? (3) Are there sex-specific differences in sacral anatomy and are these correlated with known anthropometric parameters? CT scans of pelves of 280 healthy patients acquired exclusively for medical indications such as polytrauma (20%), CT angiography (70%), and other reasons (10%), were segmented manually. Using an advanced CT-based image analysis system, the mean shape of all segmented pelves was generated and functioned as a template. On this template, the cylindric transsacral osseous corridor at the level of the S1 and S2 vertebrae was determined manually. Each pelvis then was registered to the template using a free-form registration algorithm to measure the maximum screw corridor diameters on each specimen semiautomatically. Thirty of 280 pelves (11%) had no transsacral S1 corridor owing to sacral dysmorphism. The average of maximum cylindrical diameters of the S1 corridor for the remaining 250 pelves was 12.8 mm (95% CI, 12.1-13.5 mm). A transverse corridor for S2 was found in 279 of 280 pelves, with an average of maximum cylindrical diameter of 11.6 mm (95% CI, 11.3-11.9 mm). Decreasing transsacral S1 corridor diameters are correlated with increasing transsacral S2 corridor diameters (R value for females, -0.260, p < 0.01; for males, -0.311, p < 0.001). Female specimens were more likely to have sacral dysmorphism (defined as a pelvis without a transsacral osseous corridor at the level of the S1 vertebra) than were male specimens (females, 16%; males, 7%; p < 0.003). Furthermore female pelves had smaller-corridor diameters than did male pelves (females versus males for S1: 11.7 mm [95% CI, 10.6-12.8 mm] versus 13.5 mm [95% CI, 12.6-14.4 mm], p < 0.01; and for S2: 10.6 mm [95% CI, 10.1-11.1 mm] versus 12.2 mm [95% CI, 11.8-12.6 mm ], p < 0.0001). Narrow corridors and highly individual, sex-dependent variance of morphologic features of the sacrum make transsacral implant placement technically demanding. Individual preoperative axial-slice CT scan analyses and orthogonal coronal and sagittal reformations are recommended to determine the prevalence of sufficient-sized osseous corridors on both levels for safe screw placements, especially in female patients, owing to their smaller corridor diameters and higher rate of sacral dysmorphism.

Diel movement and habitat use of the golden trout Oncorhynchus mykiss aguabonita in their native habitat on the Golden Trout Wilderness, California

Treesearch

K.R. Matthews

1996-01-01

Abstract.—I used radio transmitters to determine the diel habitat use and movement patterns of California golden trout Oncorhynchus mykiss aquabonita inside and outside cattle exclosures on the South Fork Kern River, Golden Trout Wilderness, California. Twenty-three golden trout were monitored from September 10 to 19, 1993, during 216 diel-tracking hours at four study...

Influence of livestock grazing on C sequestration in semi-arid mixed-grass and short-grass rangelands

Treesearch

J.D. Reeder; G.E. Schuman

2001-01-01

We evaluated the effects of livestock grazing on C content of the plant-soil system (to 60 cm) of two semi-arid grasslands: a mixed-grass prairie (grazed 12 years), and a short-grass steppe (grazed 56 years). Grazing treatments included season-long grazing at heavy and light stocking rates, and non-grazed exclosures. Significantly higher soil C (0-30cm) was measured in...

3. DODGEVILLE MILL COMPLEX ADJACENT TO NORTHEAST CORRIDOR DODGEVILLE, BRISTOL ...

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

3. DODGEVILLE MILL COMPLEX ADJACENT TO NORTHEAST CORRIDOR DODGEVILLE, BRISTOL CO., MA. Sec. 4116, MP 195.55. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

1. HEBRONVILLE MILL COMPLEX ADJACENT TO NORTHEAST CORRIDOR. HEBRONVILLE, BRISTOL ...

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

1. HEBRONVILLE MILL COMPLEX ADJACENT TO NORTHEAST CORRIDOR. HEBRONVILLE, BRISTOL CO., MA. Sec. 4116, MP 193.75. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

Delaware's transportation agenda in the northeast corridor.

DOT National Transportation Integrated Search

2009-10-01

The fractionated governance structure of the entire Northeast Corridor (Warren 2009) is also : evidenced within the Baltimore-to-Philadelphia portion, which contains the entire extent of : Delawares claim to the corridor. Though comprising only a ...

24. View looking north up corridor from Charles Street Bridge. ...

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

24. View looking north up corridor from Charles Street Bridge. Providence, Providence Co., RI. Sec. 4116, mp 186.44. - Northeast Railroad Corridor, Amtrak route between CT & MA state lines, Providence, Providence County, RI

35. OUTER DRAWBRIDGE, ENTRY TO THE PROTECTIVE CORRIDOR BETWEEN THE ...

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

35. OUTER DRAWBRIDGE, ENTRY TO THE PROTECTIVE CORRIDOR BETWEEN THE RAVELIN AND THE CASTILLO, AS SEEN FROM WITHIN THE CORRIDOR - Castillo de San Marcos, 1 Castillo Drive, Saint Augustine, St. Johns County, FL

I-95 Corridor Crash Data Reporting Methods

DOT National Transportation Integrated Search

2010-06-01

Access to timely and accurate crash data is essential to improving safety and efficiency on the I-95 Corridor's transportation network. Crash data are used throughout the corridor by law enforcement, departments of transportation, licensing agencies ...

Corridor management and preservation in Texas : 2010 workshops

DOT National Transportation Integrated Search

2010-01-01

2007 RMC Project 05606 : Report 56061, Creating Partnerships with Local Communities to Manage and Preserve Corridors Basis for Workshop; 5606P1, Guidelines on Corridor Management and Preservation; 5606S, Summary Report. Workshop is an ...

ICMS concept of operations for a generic corridor

DOT National Transportation Integrated Search

2006-04-18

This Generic Concept of Operations for Integrated Corridor Management (ICM) has been developed as part of Phase 1 (Foundational Research) for the Federal Highway Administration and the Federal Transit Administration (FHWA/FTA) Integrated Corridor Man...

Service life of treated and untreated fence posts on the Pringle Falls Experimental Forest.

Treesearch

Walter G. Dahms

1952-01-01

The service life of lodgepole pine fence posts can be greatly extended by a good preservative treatment, After more than 15 years, however, little or no difference can be found between treated lodgepole pine posts and untreated Western redcedar posts. These conclusions have been reached as a result of observations on 517 lodgepole pins posts for 16 years and 355 cedar...

A Comparison of Herpetofaunal Sampling Effectiveness of Pitfall, Single-ended, and Double-ended Funnel Traps Used with Drift Fences

Treesearch

Cathryn H. Greenberg; Daniel G. Neary; Larry D. Harris

1994-01-01

We assessed the relative effectiveness of pitfalls, single-ended, and double-ended funnel traps at 12 replicate sites in sand pine scrub using drift fence arrays. Pitfalls captured fewer species but yielded more individuals of many species and higher average species richness than funnel traps. Pitfalls and funnel traps exhibited differential capture bias probably due...

SU-G-TeP4-15: The Roucoulette: A Set of Quality Control Tests for Dynamic Trajectory (4Pi) Treatment Delivery Techniques

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

Teke, T

Purpose: To present and validate a set of quality control tests for trajectory treatment delivery using synchronized dynamic couch (translation and rotation), MLC and collimator motion. Methods: The quality control tests are based on the Picket fence test, which consist of 5 narrow band 2mm width spaced at 2.5cm intervals, and adds progressively synchronized dynamic motions. The tests were exposed on GafChromic EBT3 films. The first test is a regular (no motion and MLC static while beam is on) Picket Fence test used as baseline. The second test includes simultaneous collimator and couch rotation, each stripe corresponding to a differentmore » rotation speed. Errors in these tests were introduced (0.5 degree and 1 degree error in rotation synchronization) to assess the error sensitivity of this test. The second test is similar to the regular Picket Fence but now including dynamic MLC motion and couch translation (including acceleration during delivery) while the beam is on. Finally in the third test, which is a combination of the first and second test, the Picket Fence pattern is delivered using synchronized collimator and couch rotation and synchronized dynamic MLC and couch translation including acceleration. Films were analyzed with FilmQA Pro. Results: The distance between the peaks in the dose profile where measured (18.5cm away from the isocentre in the inplane direction where non synchronized rotation would have the largest effect) and compared to the regular Picket Fence tests. For well synchronized motions distances between peaks where between 24.9–25.4 mm identical to the regular Picket Fence test. This range increased to 24.4–26.4mm and 23.4–26.4mm for 0.5 degree and 1 degree error respectively. The amplitude also decreased up to 15% when errors are introduced. Conclusion: We demonstrated that the Roucoulette tests can be used as a quality control tests for trajectory treatment delivery using synchronized dynamic motion.« less

Rangeland Condition Monitoring: A New Approach Using Cross-Fence Comparisons of Remotely Sensed Vegetation

PubMed Central

Kilpatrick, Adam D.; Lewis, Megan M.; Ostendorf, Bertram

2015-01-01

A need exists in arid rangelands for effective monitoring of the impacts of grazing management on vegetation cover. Monitoring methods which utilize remotely-sensed imagery may have comprehensive spatial and temporal sampling, but do not necessarily control for spatial variation of natural variables, such as landsystem, vegetation type, soil type and rainfall. We use the inverse of the red band from Landsat TM satellite imagery to determine levels of vegetation cover in a 22,672km2 area of arid rangeland in central South Australia. We interpret this wealth of data using a cross-fence comparison methodology, allowing us to rank paddocks (fields) in the study region according to effectiveness of grazing management. The cross-fence comparison methodology generates and solves simultaneous equations of the relationship between each paddock and all other paddocks, derived from pairs of cross-fence sample points. We compare this ranking from two image dates separated by six years, during which management changes are known to have taken place. Changes in paddock rank resulting from the cross-fence comparison method show strong correspondence to those predicted by grazing management in this region, with a significant difference between the two common management types; a change from full stocking rate to light 20% stocking regime (Major Stocking Reduction) and maintenance of full 100% stocking regime (Full Stocking Maintained) (P = 0.00000132). While no paddocks had a known increase in stocking rate during the study period, many had a reduction or complete removal in stock numbers, and many also experienced removals of pest species, such as rabbits, and other ecosystem restoration activities. These paddocks generally showed an improvement in rank compared to paddocks where the stocking regime remained relatively unchanged. For the first time, this method allows us to rank non-adjacent paddocks in a rangeland region relative to each other, while controlling for natural spatio-temporal variables such as rainfall, soil type, and vegetation community distributions, due to the nature of the cross-fence experimental design, and the spatially comprehensive data available in satellite imagery. This method provides a potential tool to aid land managers in decision making processes, particularly with regard to stocking rates. PMID:26565801

Nitrogen and carbon soil dynamics in response to climate change in a high-elevation ecosystem in the Rocky Mountains, U.S.A.

USGS Publications Warehouse

Williams, M.W.; Brooks, P.D.; Seastedt, T.

1998-01-01

We have implemented a long-term snow-fence experiment at the Niwot Ridge Long-Term Ecological Research (NWT) site in the Colorado Front Range of the Rocky Mountains, U.S.A., to assess the effects of climate change on alpine ecology and biogeochemical cycles. The responses of carbon (C) and nitrogen (N) dynamics in high-elevation mountains to changes in climate are investigated by manipulating the length and duration of snow cover with the 2.6 x 60 m snow fence, providing a proxy for climate change. Results from the first year of operation in 1994 showed that the period of continuous snow cover was increased by 90 d. The deeper and earlier snowpack behind the fence insulated soils from winter air temperatures, resulting in a 9??C increase in annual minimum temperature at the soil surface. The extended period of snow cover resulted in subnivial microbial activity playing a major role in annual C and N cycling. The amount of C mineralized under the snow as measured by CO2 production was 22 g m-2 in 1993 and 35 g m-2 in 1994, accounting for 20% of annual net primary aboveground production before construction of the snow fence in 1993 and 31% after the snow fence was constructed in 1994. In a similar fashion, maximum subnivial N2O flux increased 3-fold behind the snow fence, from 75 ??g N m-2 d-1 in 1993 to 250 ??g N m-2 d-1 in 1994. The amount of N lost from denitrification was greater than the annual atmospheric input of N in snowfall. Surface litter decomposition studies show that there was a significant increase in the litter mass loss under deep and early snow, with no significant change under medium and little snow conditions. Changes in climate that result in differences in snow duration, depth, and extent may therefore produce large changes in the C and N soil dynamics of alpine ecosystems.

METHODS FOR MULTI-SPATIAL SCALE CHARACTERIZATION OF RIPARIAN CORRIDORS

EPA Science Inventory

This paper describes the application of aerial photography and GIS technology to develop flexible and transferable methods for multi-spatial scale characterization and analysis of riparian corridors. Relationships between structural attributes of riparian corridors and indicator...

Final report : Dallas Integrated Corridor Management (ICM) Demonstration Project.

DOT National Transportation Integrated Search

2015-08-01

The Dallas Area Rapid Transit (DART) is leading the US-75 Integrated Corridor Management (ICM) Demonstration Project for the Dallas region. Coordinated corridor operations and management is predicated on being able to share transportation information...

Test report : Dallas Integrated Corridor Management (ICM) demonstration project.

DOT National Transportation Integrated Search

2015-05-01

The Dallas Area Rapid Transit (DART) is leading the US 75 Integrated Corridor Management (ICM) Demonstration Project for the Dallas region. Coordinated corridor operations and management is predicated on being able to share transportation information...

23. Looking N up corridor from Chick Interlocking Tower. Boston, ...

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

23. Looking N up corridor from Chick Interlocking Tower. Boston, Suffolk Co., MA. Sec. 4116, MP 227.09. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

Training plan : Dallas Integrated Corridor Management (ICM) demonstration project.

DOT National Transportation Integrated Search

2013-01-01

The Dallas Area Rapid Transit (DART) is leading the US 75 Integrated Corridor Management (ICM) Demonstration Project for the Dallas region. Coordinated corridor operations and management is predicated on being able to share transportation information...

90-94 ITS Intercity Corridor Study - Strategic Deployment Plan

DOT National Transportation Integrated Search

1996-12-01

PUBLIC-PRIVATE PARTNERSHIP, COMMERCIAL VEHICLES OPERATIONS OR CVO : THE IH 90/94 ITS INTERCITY CORRIDOR STRATEGIC DEPLOYMENT PLAN IS AN APPROACH FOR IMPLEMENTING INTELLIGENT TRANSPORTATION SYSTEMS (ITS) IN THE IH 90/94 CORRIDORS THAT TRAVERSE THE ...

76 FR 31008 - North Central Iowa Rail Corridor, LLC-Acquisition Exemption-Union Pacific Railroad Company

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-27

... Rail Corridor, LLC--Acquisition Exemption-- Union Pacific Railroad Company North Central Iowa Rail Corridor, LLC (NCIRC), a noncarrier, has filed a verified notice of exemption under 49 [[Page 31009

13. I95 bridge crossing corridor with Providence Station in background. ...

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

13. I-95 bridge crossing corridor with Providence Station in background. Providence, Providence County, RI. sec. 4116, mp 185.15. - Northeast Railroad Corridor, Amtrak route between CT & MA state lines, Providence, Providence County, RI

Integrated corridor management : implementation guide and lessons learned.

DOT National Transportation Integrated Search

2012-02-01

This implementation guide is intended for use by adopters of integrated corridor management (ICM) approaches and strategies to address congestion and travel time reliability issues within specific travel corridors. It introduces the topic of ICM and ...

Silicon Valley Smart Corridor : final evaluation report

DOT National Transportation Integrated Search

2003-08-01

This document summarizes the findings from the evaluation of the integrated freeway, arterial, and incident management system known as the Silicon Valley Smart Corridor (SVSC). Centered along the Highway 17/Interstate 880 corridor in San Jose, Califo...

77 FR 73734 - Northeast Corridor Safety Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-11

.... 5] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of a Northeast Corridor Safety... Committee is made up of stakeholders operating on the [[Page 73735

Using collaborative tools for energy corridor planning.

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

Kuiper, J. A.; Cantwell, B.; Hlohowskyj, I.

2008-01-01

In November 2007, the Draft Programmatic Environmental Impact Statement on Designation of Energy Corridors on Federal Land in the Western 11 States was released. The draft proposes a network of 6055 miles of energy corridors on lands managed by seven different federal agencies. Determining the proposed locations of the corridors was a large collaborative effort among the agencies and included local, state, and federal land managers. To connect this geographically dispersed group of people, the project team employed a variety of approaches to communicate corridor siting issues, including sharing GIS layers and electronic maps, a downloadable GIS database and ArcReadermore » project, workshops, and Internet webcast teleconferences. This collaborative approach allowed difficult siting issues to be understood and discussed from many perspectives, which resulted in rapid and effective decision making. The result was a proposed corridor system that avoids many sensitive resources and protected lands while accommodating expected energy development.« less

Moving shadows contribute to the corridor illusion in a chimpanzee (Pan troglodytes).

PubMed

Imura, Tomoko; Tomonaga, Masaki

2009-08-01

Previous studies have reported that backgrounds depicting linear perspective and texture gradients influence relative size discrimination in nonhuman animals (known as the "corridor illusion"), but research has not yet identified the other kinds of depth cues contributing to the corridor illusion. This study examined the effects of linear perspective and shadows on the responses of a chimpanzee (Pan troglodytes) to the corridor illusion. The performance of the chimpanzee was worse when a smaller object was presented at the farther position on a background reflecting a linear perspective, implying that the corridor illusion was replicated in the chimpanzee (Imura, Tomonaga, & Yagi, 2008). The extent of the illusion changed as a function of the position of the shadows cast by the objects only when the shadows were moving in synchrony with the objects. These findings suggest that moving shadows and linear perspective contributed to the corridor illusion in a chimpanzee. Copyright 2009 APA, all rights reserved.

Abort-once-around entry dispersion corridor analysis. [for space shuttle reentry

NASA Technical Reports Server (NTRS)

Kyle, H. C.

1975-01-01

Abort-Once-Around (AOA) entry dispersion corridors were determined for Shuttle Mission 3A. These corridors are presented as plots of entry interface flight path angle versus range to target. The methods used to determine the corridors are discussed. Major dispersion sources are discussed and results presented. While specific trajectory inputs and constraints are subject to change, the dispersion corridors show the trends under consideration. The corridors presented show the delta V advantage of the two-burn over the one-burn AOA. The atmospheric dispersion study illustrates the need to target for the seasonal atmosphere. The 40 deg/30 deg angle of attack (alpha) (TPS design) profile did not provide adequate crossrange capability with worst case aerodynamic dispersions. This problem was alleviated with the change to a 38 deg/28 deg alpha profile. The backface temperatures calculated were generally higher than the present limits.

Insights on the extraordinary tolerance to alcohols of Fe-N-C cathode catalysts in highly performing direct alcohol fuel cells

DOE PAGES

Sebastian, David; Serov, Alexey; Matanovic, Ivana; ...

2017-02-21

Direct alcohol fuel cells (DAFCs) represent the best alternative to batteries for portable and auxiliary power units application due to the high energy density of short chain alcohols. Currently, the utilization of the best platinum group metal (PGM) cathode catalysts is limited, not only by a high cost and scarce resources, but also by the inefficient oxygen reduction reaction (ORR) when permeated alcohols adsorb on the catalytic active sites. In this work, a highly active Fe-N-C catalyst derived from the pyrolysis of nicarbazin (a nitrogen charge transfer organic salt) and an iron precursor has been investigated to get insights onmore » the extraordinary tolerance to the presence of alcohols (methanol and ethanol) of such a PGM-free catalyst. Density functional theory (DFT) calculations demonstrate for the first time that Fe-N 4 and Fe-N 2C 2 active sites preferentially adsorb oxygen with much higher energy than methanol, ethanol and products of partial ethanol oxidation (0.73–1.16 eV stronger adsorption), while nitrogen-carbon related sites (pyridinic and graphitic nitrogen) are much less selective towards ORR. Half-cell electrochemical characterization showed that the Fe-N-C catalyst overcomes Pt ORR activity in acidic medium with methanol or ethanol concentrations as low as 0.01 M. The feasibility of DAFCs operation based on high methanol (up to 17 M) and ethanol (up to 5 M) concentration thanks to the utilization of Fe-N-C cathode catalyst is demonstrated. Lastly, a new strategy is proposed for DAFCs where using Pt only at the anode and Fe-N-C at the cathode allows extending the device energy density compared to PGM-based catalysts at both electrodes.« less

Atmospheric Dispersion about a Heavy Gas Vapor Detention System.

NASA Astrophysics Data System (ADS)

Shin, Seong-Hee

Dispersion of liquefied natural gas (LNG) in the event of an accidental spill is a major concern in LNG storage and transport safety planning, hazard response, and facility siting. Falcon Series large scale LNG spill experiments were planned by Lawrence Livermore National Laboratory (LLNL) for the Department of Transportation (DOT) and the Gas Research Institute (GRI) as part of a joint government/industry study in 1987 to evaluate the effectiveness of vapor fences as a mitigating technique for accidental release of LNG and to assist in validating wind tunnel and numerical methods for vapor dispersion simulation. Post-field-spill wind-tunnel experiments were performed in Environmental Wind Tunnel (EWT) (1988, 1989) to augment the LNG Vapor Fence Program data obtained during the Falcon Test Series. The program included four different model length scales and two different simulant gases. The purpose of this program is to provide a basis for the analysis of the simulation of physical modeling tests using proper physical modeling techniques and to assist in the development and verification of analytical models. Field data and model data were compared and analyzed by surface pattern comparisons and statistical methods. A layer-averaged slab model developed by Meroney et al. (1988) (FENC23) was expanded to evaluate an enhanced entrainment model proposed for dense gas dispersion including the effect of vapor barriers, and the numerical model was simulated for Falcon tests without the fence and with the vapor fence to examine the effectiveness of vapor detention system on heavy gas dispersion. Model data and the field data were compared with the numerical model data, and degree of similarity between data were assessed.

Escape rates and biting histories of dogs confined to their owner's property through the use of various containment methods.

PubMed

Starinsky, Nicole S; Lord, Linda K; Herron, Meghan E

2017-02-01

OBJECTIVE To determine escape rates for dogs confined to their owner's property by various containment methods and determine whether biting history was associated with containment method. DESIGN Cross-sectional survey. SAMPLE 974 owners of 1,053 dogs. PROCEDURES Individuals patronizing pet stores in Columbus, Ohio, were recruited to complete a survey on the method they used to confine their dogs to their property and their dogs' behavior history. RESULTS Dogs were confined to their owner's property by a physical fence (821/1,053 [78.0%]), electronic fence (150/1,053 [14.2%]), or tether system (82/1,053 [7.8%]). Dogs confined by an electronic fence were more likely to have escaped (66/150 [44.0%]) than were dogs confined by a see-through fence (153/658 [23.3%]), privacy fence (38/163 [23.3%]), or tether (22/82 [26.8%]). Forty-eight (4.6%) dogs had reportedly bitten a person in the past, and 81 (7.7%) had reportedly bitten another dog, but containment method was not significantly associated with whether dogs had ever bitten a person or another dog. Greeting behavior (growling, snarling, or trying to bite) was significantly associated with a history of biting a person or another dog. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that escape rate, but not biting history, was associated with the method owners used to confine dogs to their properties. Greeting behavior was associated with biting history, suggesting that owners of dogs that growl, snarl, or attempt to bite when meeting an unfamiliar person or dog should seek assistance to prevent future bites.

Properties of body composition of female representatives of the Polish national fencing team - the sabre event.

PubMed

Jagiełło, Władysław; Marina, Jagiełło; Maciej, Kalina Roman; Jan, Barczyński Bartłomiej; Artur, Litwiniuk; Jarosław, Klimczak

2017-12-01

Fencing is a combat sport whose form of direct confrontation involves hitting the opponent with a weapon. The purpose of the study was to determine the properties of body composition of female representatives of the Polish national fencing team. The study involved 11 female athletes of the Polish national fencing team. Their age was 16-22 years (19±2.32), body weight 52-78 kg (59.7±7.4), body height 158-183 cm (167.46±6.10) and the training experience 7.64±3.47 years. The reference group consisted of 153 students of Warsaw University of Technology (Poland). Twenty basic somatic characteristics were measured. The following indices were calculated: slenderness, Rohrer's, BMI, Manouvrier's, and pelvic-shoulder indices. Density of the body, total body fat, active tissue, the overall profile of body composition and internal proportions of the body were determined. Analysis of internal proportions of factors of the athletes' body composition revealed significant differences in particular groups of features. The total size of the athletes' bodies is due to less-than-average magnitude of the length and stoutness characteristics and a high magnitude of adiposity (M = 0.63) in the Polish female national team of fencers (sabre) calculated from the normalized values for the control group. The proportions of features within the analysed factors revealed a significant advantage of the length of the upper extremity over the lower one and a distinct advantage of forearm musculature. The specific profile of body composition of female athletes practising sabre fencing is most likely due to long-term effects of training as well as the system of selection of persons with specific somatic prerequisites developed in the course of many years of training practice.

Insights on the extraordinary tolerance to alcohols of Fe-N-C cathode catalysts in highly performing direct alcohol fuel cells

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

Sebastian, David; Serov, Alexey; Matanovic, Ivana

Direct alcohol fuel cells (DAFCs) represent the best alternative to batteries for portable and auxiliary power units application due to the high energy density of short chain alcohols. Currently, the utilization of the best platinum group metal (PGM) cathode catalysts is limited, not only by a high cost and scarce resources, but also by the inefficient oxygen reduction reaction (ORR) when permeated alcohols adsorb on the catalytic active sites. In this work, a highly active Fe-N-C catalyst derived from the pyrolysis of nicarbazin (a nitrogen charge transfer organic salt) and an iron precursor has been investigated to get insights onmore » the extraordinary tolerance to the presence of alcohols (methanol and ethanol) of such a PGM-free catalyst. Density functional theory (DFT) calculations demonstrate for the first time that Fe-N 4 and Fe-N 2C 2 active sites preferentially adsorb oxygen with much higher energy than methanol, ethanol and products of partial ethanol oxidation (0.73–1.16 eV stronger adsorption), while nitrogen-carbon related sites (pyridinic and graphitic nitrogen) are much less selective towards ORR. Half-cell electrochemical characterization showed that the Fe-N-C catalyst overcomes Pt ORR activity in acidic medium with methanol or ethanol concentrations as low as 0.01 M. The feasibility of DAFCs operation based on high methanol (up to 17 M) and ethanol (up to 5 M) concentration thanks to the utilization of Fe-N-C cathode catalyst is demonstrated. Lastly, a new strategy is proposed for DAFCs where using Pt only at the anode and Fe-N-C at the cathode allows extending the device energy density compared to PGM-based catalysts at both electrodes.« less

Effects of white-tailed deer and invasive plants on the herb layer of suburban forests.

PubMed

Morrison, Janet A

2017-11-01

Lack of hunting and predators and proximity to human communities make suburban forests prone to high deer abundance and non-native plant invasions. I investigated these likely drivers of community structure in the herb layers of six suburban forests in one region of New Jersey, USA. In 223 plots I assessed the herb layer response to 2.5 years with or without deer fencing and the early stage of invasion from seed additions of Microstegium vimineum , an invasive, annual grass. Non-native plants and herbaceous native plants were affected very little by fencing or M. vimineum invasion. In contrast, across all forests the combination of deer access and M. vimineum addition had a strongly negative effect on woody native percent cover. Forests differed in overall fencing effects on woody natives; their cover was greater in fenced plots in just three forests, suggesting greater deer pressure in those forests during the experiment. The early invasion by M. vimineum was greatest in two of these same forests, but was not influenced by fencing. Multi-group structural equation modelling compared two groups of forests that differed in vegetation abundance and other characteristics. It paralleled the results above and also showed no negative influence of non-native cover on native cover, even in the forests where non-native cover was greater. It identified a positive effect of light level on herb layer plants in the forests with less vegetation, and also revealed a positive effect of soil water potential (SWP) on non-native plants in the forests with more vegetation, which had higher SWP. These suburban forests within a common region varied widely in native and non-native herb layer abundance, the early success of M. vimineum invasion and the herb layer's response to early invasion and protection from deer.

Submittal of Final Post-Closure Inspection Letter Report for Corrective Action Unit 112: Area 23 Hazardous Waste Trenches, Nevada Test Site, Nevada, Revision 0, December 2007; DOE/NV--1103

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

NSTec Environmental Restoration

This letter serves as the post-closure monitoring letter report for the above Corrective Action Unit (CAU) for the period October 2006-September 2007. Quarterly inspections were conducted on December 20,2006; March 29,2007; June 13,2007; and September 27, 2007, to observe the condition of the gate, use restriction warning signs, monuments, fencing, trenches, soil covers, and monitoring well covers. The first inspection was conducted on December 20,2006. Signs, fencing, riprap, monuments, and monitoring well covers were in excellent condition. No cracking, erosion, or subsidence was observed on the covers. No issues or concerns were identified, and no corrective actions were recommended. Themore » second inspection was conducted on March 29,2007. Signs, fencing, riprap, monuments, and monitoring well covers were in excellent condition. No cracking, erosion, or subsidence was observed on the covers. Vegetation that was observed to be growing in several locations on the cover was the only identified concern, for which removal was recommended. Vegetation was removed on May 24,2007. The third inspection was conducted on June 13,2007. Signs, fencing, riprap, monuments, and monitoring well covers were in excellent condition. No cracking, erosion, or subsidence was observed on the covers. No issues or concerns were identified, and no corrective actions were recommended. The fourth inspection was conducted on September 27,2007. Signs, fencing, riprap, monuments, and monitoring well covers were in excellent condition. No cracking, erosion, or subsidence was observed on the covers. No issues or concerns were identified, and no corrective actions were recommended. The post-closure inspection checklists for CAU 112 are attached. Photographs and field notes taken during site inspections are maintained in the project files.« less