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Sample records for beaver dam offspring

  1. Measuring taste impairment in epidemiologic studies: the Beaver Dam Offspring Study.

    Science.gov (United States)

    Cruickshanks, K J; Schubert, C R; Snyder, D J; Bartoshuk, L M; Huang, G H; Klein, B E K; Klein, R; Nieto, F J; Pankow, J S; Tweed, T S; Krantz, E M; Moy, G S

    2009-07-01

    Taste or gustatory function may play an important role in determining diet and nutritional status and therefore indirectly impact health. Yet there have been few attempts to study the spectrum of taste function and dysfunction in human populations. Epidemiologic studies are needed to understand the impact of taste function and dysfunction on public health, to identify modifiable risk factors, and to develop and test strategies to prevent clinically significant dysfunction. However, measuring taste function in epidemiologic studies is challenging and requires repeatable, efficient methods that can measure change over time. Insights gained from translating laboratory-based methods to a population-based study, the Beaver Dam Offspring Study (BOSS) will be shared. In this study, a generalized labeled magnitude scale (gLMS) method was used to measure taste intensity of filter paper disks saturated with salt, sucrose, citric acid, quinine, or 6-n-propylthiouracil, and a gLMS measure of taste preferences was administered. In addition, a portable, inexpensive camera system to capture digital images of fungiform papillae and a masked grading system to measure the density of fungiform papillae were developed. Adult children of participants in the population-based Epidemiology of Hearing Loss Study in Beaver Dam, Wisconsin, are eligible for this ongoing study. The parents were residents of Beaver Dam and 43-84 years of age in 1987-1988; offspring ranged in age from 21-84 years in 2005-2008. Methods will be described in detail and preliminary results about the distributions of taste function in the BOSS cohort will be presented.

  2. Dry eye in the beaver dam offspring study: prevalence, risk factors, and health-related quality of life.

    Science.gov (United States)

    Paulsen, Adam J; Cruickshanks, Karen J; Fischer, Mary E; Huang, Guan-Hua; Klein, Barbara E K; Klein, Ronald; Dalton, Dayna S

    2014-04-01

    To estimate dry eye prevalence in the Beaver Dam Offspring Study (BOSS), including a young adult population, and investigate associated risk factors and impact on health-related quality of life. Cohort study. The BOSS (2005-2008) is a study of aging in the adult offspring of the population-based Epidemiology of Hearing Loss Study cohort. Questionnaire data on health history, medication use, risk factors, and quality of life were available for 3275 participants. Dry eye was determined by self-report of frequency of symptoms and the intensity of those symptoms. Associations between dry eye and risk factors were analyzed using logistic regression. The prevalence of dry eye in the BOSS was 14.5%: 17.9% of women and 10.5% of men. In a multivariate model, statistically significant associations were found with female sex (odds ratio [OR], 1.68; 95% confidence interval [CI], 1.33-2.11), current contact lens use (OR, 2.01; 95% CI, 1.53-2.64), allergies (OR, 1.59; 95% CI, 1.22-2.08), arthritis (OR, 1.44; 95% CI, 1.12-1.85), thyroid disease (OR, 1.43; 95% CI, 1.02-1.99), antihistamine use (OR, 1.54; 95% CI, 1.18-2.02), and steroid use (OR, 1.54; 95% CI, 1.16-2.06). Dry eye was also associated with lower scores on the Medical Outcomes Study Short Form 36 (β = -3.9, P < .0001) as well as on the National Eye Institute 25-Item Visual Function Questionnaire (NEI VFQ-25) (β = -3.4, P < .0001) when controlling for age, sex, and comorbid conditions. The prevalence of dry eye and its associated risk factors in the BOSS were similar to previous studies. In this study, dry eye was associated with lower quality of life on a health-related quality-of-life instrument and the vision-specific NEI VFQ-25. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Modeling the capacity of riverscapes to support beaver dams

    Science.gov (United States)

    Macfarlane, William W.; Wheaton, Joseph M.; Bouwes, Nicolaas; Jensen, Martha L.; Gilbert, Jordan T.; Hough-Snee, Nate; Shivik, John A.

    2017-01-01

    The construction of beaver dams facilitates a suite of hydrologic, hydraulic, geomorphic, and ecological feedbacks that increase stream complexity and channel-floodplain connectivity that benefit aquatic and terrestrial biota. Depending on where beaver build dams within a drainage network, they impact lateral and longitudinal connectivity by introducing roughness elements that fundamentally change the timing, delivery, and storage of water, sediment, nutrients, and organic matter. While the local effects of beaver dams on streams are well understood, broader coverage network models that predict where beaver dams can be built and highlight their impacts on connectivity across diverse drainage networks are lacking. Here we present a capacity model to assess the limits of riverscapes to support dam-building activities by beaver across physiographically diverse landscapes. We estimated dam capacity with freely and nationally-available inputs to evaluate seven lines of evidence: (1) reliable water source, (2) riparian vegetation conducive to foraging and dam building, (3) vegetation within 100 m of edge of stream to support expansion of dam complexes and maintain large colonies, (4) likelihood that channel-spanning dams could be built during low flows, (5) the likelihood that a beaver dam is likely to withstand typical floods, (6) a suitable stream gradient that is neither too low to limit dam density nor too high to preclude the building or persistence of dams, and (7) a suitable river that is not too large to restrict dam building or persistence. Fuzzy inference systems were used to combine these controlling factors in a framework that explicitly also accounts for model uncertainty. The model was run for 40,561 km of streams in Utah, USA, and portions of surrounding states, predicting an overall network capacity of 356,294 dams at an average capacity of 8.8 dams/km. We validated model performance using 2852 observed dams across 1947 km of streams. The model showed

  4. Alteration of stream temperature by natural and artificial beaver dams.

    Science.gov (United States)

    Weber, Nicholas; Bouwes, Nicolaas; Pollock, Michael M; Volk, Carol; Wheaton, Joseph M; Wathen, Gus; Wirtz, Jacob; Jordan, Chris E

    2017-01-01

    Beaver are an integral component of hydrologic, geomorphic, and biotic processes within North American stream systems, and their propensity to build dams alters stream and riparian structure and function to the benefit of many aquatic and terrestrial species. Recognizing this, beaver relocation efforts and/or application of structures designed to mimic the function of beaver dams are increasingly being utilized as effective and cost-efficient stream and riparian restoration approaches. Despite these verities, the notion that beaver dams negatively impact stream habitat remains common, specifically the assumption that beaver dams increase stream temperatures during summer to the detriment of sensitive biota such as salmonids. In this study, we tracked beaver dam distributions and monitored water temperature throughout 34 km of stream for an eight-year period between 2007 and 2014. During this time the number of natural beaver dams within the study area increased by an order of magnitude, and an additional 4 km of stream were subject to a restoration manipulation that included installing a high-density of Beaver Dam Analog (BDA) structures designed to mimic the function of natural beaver dams. Our observations reveal several mechanisms by which beaver dam development may influence stream temperature regimes; including longitudinal buffering of diel summer temperature extrema at the reach scale due to increased surface water storage, and creation of cool-water channel scale temperature refugia through enhanced groundwater-surface water connectivity. Our results suggest that creation of natural and/or artificial beaver dams could be used to mitigate the impact of human induced thermal degradation that may threaten sensitive species.

  5. 33 CFR 117.705 - Beaver Dam Creek.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Beaver Dam Creek. 117.705 Section 117.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.705 Beaver Dam Creek. The draw of the...

  6. Hydrogen sulfide concentration in Beaver Dam Creek

    International Nuclear Information System (INIS)

    Kiser, D.L.

    1979-01-01

    Concentration-time profiles calculated with LODIPS for various hypothetical releases of hydrogen sulfide from the heavy water extraction facility predict lethal conditions for swamp fish from releases as small as 568 kg discharged over a period of 30 minutes or from releases of 1818 kg discharged over a period of 6 hours or less. The necessary volatilization and oxidation coefficients for LODIPS were derived from field measurements following planned releases of H 2 S. Upsets in the operation of the wastewater strippers in the Girdler-Sulfide (GS) heavy water extraction facility in D Area have released significant amounts of dissolved H 2 S to Beaver Dam Creek. Because H 2 S is toxic to fish in concentrations as low as 1 mg/liter, the downstream environmental impact of H 2 S releases from D Area was evaluated

  7. Beaver damming, fluvial geomorphology, and climate in Yellowstone National Park, Wyoming

    Science.gov (United States)

    Persico, L.; Meyer, G.

    2008-12-01

    Beaver habitation is an important component of many fluvial landscapes that can impact a variety of hydrologic, geomorphic, and ecologic processes. Beaver damming, via long term valley aggradation, is thought to be important to the postglacial geomorphic evolution of many smaller mountain stream networks in the western United States. Loss of beaver dams can also cause rapid channel incision. Although several studies have documented rapid short-term aggradation of channels behind single beaver dams, there is little actual data on the long-term cumulative effect of beaver damming. In Yellowstone''s Northern Range, field surveys and stratigraphic section along six streams in the Northern Range reveal net thickness of mostly beaver-pond deposits. We estimate that reaches with clear morphologic and stratigraphic evidence for beaver-related aggradation constitute about 19% of the total stream network length. Reaches with probable and possible beaver-related aggradation make up an additional 8% and 2% of the network, respectively. The remaining 71% of the network has no clear evidence for beaver-related aggradation. Thirty-nine radiocarbon ages on beaver-pond deposits in northern Yellowstone fall primarily within the last 4000 yr, but gaps in dated beaver occupation from 2200-1800 and 950-750 cal yr BP correspond with severe and persistent droughts that likely caused low to ephemeral discharges in smaller streams. In the last two decades, severe drought has also caused streams that were occupied by beaver in the 1920s to become ephemeral. Beaver have been largely absent from the Northern Range since the mid-20th century, probably due to multiple ecological and climatic factors. This loss of beaver is thought to have led to widespread degradation of stream and riparian habitat via channel incision. Although 20th-century beaver loss has caused significant channel incision at some former dam sites, downcutting elsewhere in northern Yellowstone is unrelated to beaver dams or

  8. Colonial Era Impoundment of the Northeastern United States: Beaver Trapping and Low- head Dam Construction

    Science.gov (United States)

    Salant, N.; Bain, D.; Brandt, S.

    2008-12-01

    Hydrologic systems of the northeastern United States were transformed by European settler activities. The colonial economy shifted engineered water structures from beaver dams to human dams built for power generation. While the geomorphic effects of human-constructed dams have recently garnered considerable attention, few studies have investigated how intensive trapping for the fur trade, the near extermination of the Northeast beaver population, and the consequent loss of beaver ponds altered the regional water balance. Although reconstructions of colonial beaver populations have been made, none link the decline in beavers to its hydrologic impact. Beaver population models based on pre-colonial population estimates, historic harvest rates, and current-day population dynamics were used to simulate the corresponding decrease in pond numbers over time. Beaver populations declined dramatically during the seventeenth century, with harvest rates estimated at 2,000-10,000 beavers per year, resulting in expatriation in some sub-regions by the early 1700s. Using contemporary estimates of beaver pond volumes, the calculated loss in pond storage between 1600 and 1840 was approximately 17 million cubic meters of water and sediment, considerably larger than estimated storage gains from dam construction in the same period, suggesting that beaver eradication was a major driver of hydrologic change during the colonial era.

  9. Impacts of beaver dams on hydrologic and temperature regimes in a mountain stream

    Science.gov (United States)

    Majerova, M.; Neilson, B. T.; Schmadel, N. M.; Wheaton, J. M.; Snow, C. J.

    2015-08-01

    Beaver dams affect hydrologic processes, channel complexity, and stream temperature in part by inundating riparian areas, influencing groundwater-surface water interactions, and changing fluvial processes within stream systems. We explored the impacts of beaver dams on hydrologic and temperature regimes at different spatial and temporal scales within a mountain stream in northern Utah over a 3-year period spanning pre- and post-beaver colonization. Using continuous stream discharge, stream temperature, synoptic tracer experiments, and groundwater elevation measurements, we documented pre-beaver conditions in the first year of the study. In the second year, we captured the initial effects of three beaver dams, while the third year included the effects of ten dams. After beaver colonization, reach-scale (~ 750 m in length) discharge observations showed a shift from slightly losing to gaining. However, at the smaller sub-reach scale (ranging from 56 to 185 m in length), the discharge gains and losses increased in variability due to more complex flow pathways with beaver dams forcing overland flow, increasing surface and subsurface storage, and increasing groundwater elevations. At the reach scale, temperatures were found to increase by 0.38 °C (3.8 %), which in part is explained by a 230 % increase in mean reach residence time. At the smallest, beaver dam scale (including upstream ponded area, beaver dam structure, and immediate downstream section), there were notable increases in the thermal heterogeneity where warmer and cooler niches were created. Through the quantification of hydrologic and thermal changes at different spatial and temporal scales, we document increased variability during post-beaver colonization and highlight the need to understand the impacts of beaver dams on stream ecosystems and their potential role in stream restoration.

  10. Impact of beaver dams on abundance and distribution of anadromous salmonids in two lowland streams in Lithuania.

    Science.gov (United States)

    Virbickas, Tomas; Stakėnas, Saulius; Steponėnas, Andrius

    2015-01-01

    European beaver dams impeded movements of anadromous salmonids as it was established by fishing survey, fish tagging and redd counts in two lowland streams in Lithuania. Significant differences in abundancies of other litophilic fish species and evenness of representation by species in the community were detected upstream and downstream of the beaver dams. Sea trout parr marked with RFID tags passed through several successive beaver dams in upstream direction, but no tagged fish were detected above the uppermost dam. Increase in abundances of salmonid parr in the stream between the beaver dams and decrease below the dams were recorded in November, at the time of spawning of Atlantic salmon and sea trout, but no significant changes were detected in the sections upstream of the dams. After construction of several additional beaver dams in the downstream sections of the studied streams, abundance of Atlantic salmon parr downstream of the dams decreased considerably in comparison with that estimated before construction.

  11. Impact of beaver dams on abundance and distribution of anadromous salmonids in two lowland streams in Lithuania.

    Directory of Open Access Journals (Sweden)

    Tomas Virbickas

    Full Text Available European beaver dams impeded movements of anadromous salmonids as it was established by fishing survey, fish tagging and redd counts in two lowland streams in Lithuania. Significant differences in abundancies of other litophilic fish species and evenness of representation by species in the community were detected upstream and downstream of the beaver dams. Sea trout parr marked with RFID tags passed through several successive beaver dams in upstream direction, but no tagged fish were detected above the uppermost dam. Increase in abundances of salmonid parr in the stream between the beaver dams and decrease below the dams were recorded in November, at the time of spawning of Atlantic salmon and sea trout, but no significant changes were detected in the sections upstream of the dams. After construction of several additional beaver dams in the downstream sections of the studied streams, abundance of Atlantic salmon parr downstream of the dams decreased considerably in comparison with that estimated before construction.

  12. Channel aggradation by beaver dams on a small agricultural stream in Eastern Nebraska

    Science.gov (United States)

    M.C. McCullough; J.L. Harper; D.E. Eisenhauer; M.G. Dosskey

    2004-01-01

    We assessed the effect of beaver dams on channel gradation of an incised stream in an agricultural area of eastern Nebraska. A topographic survey was conducted of a reach of Little Muddy Creek where beaver are known to have been building dams for twelve years. Results indicating that over this time period the thalweg elevation has aggraded an average of 0.65 m by...

  13. Influence of Beaver Dams on Channel Complexity, Hydrology, and Temperature Regime in a Mountainous Stream

    Science.gov (United States)

    Majerova, M.; Neilson, B. T.; Schmadel, N. M.; Wheaton, J. M.; Snow, C. J.

    2013-12-01

    Beaver dams and beaver activity affect hydrologic processes, sediment transport, channel complexity and water quality of streams. Beaver ponds, which form behind beaver dams, increase in-channel water storage affecting the timing and volume of flow and resulting in the attenuation and flattening of the hydrograph. Channel complexity also increases the potential for transient storage (both surface and subsurface) and influences stream temperature. Impacts of beaver dams and beaver activity on stream responses are difficult to quantify because responses are dynamic and spatially variable. Few studies have focused on the reach scale temporal influences on stream responses and further research is needed particularly in quantifying the influence of beaver dams and their role in shaping the stream habitat. This study explores the changing hydrology and temperature regime of Curtis Creek, a mountainous stream located in Northern Utah, in a 560 m long reach where groundwater exchanges and temperature differences were observed over a three-year period. We have collected continuous stream discharge, stream temperature data and performed tracer experiments. During the first year, we were able to capture the pre-beaver activity. In the second year, we captured the impacts of some beaver activity with only a few dams built in the reach, while the third year included the effects of an entire active beaver colony. By the end of the study period, a single thread channel had been transformed into a channel with side channels and backwaters at multiple locations therefore increasing channel complexity. The cumulative influence of beaver dams on reach scale discharge resulted in a slightly losing reach that developed into a gaining reach. At the smaller sub-reach scale, both losing to gaining and gaining to losing transformations were observed. Temperature differences showed a warming effect of beaver dams at the reach scale. The reach stream temperature difference increased on

  14. Meta-analysis of environmental effects of beaver in relation to artificial dams

    Science.gov (United States)

    Ecke, Frauke; Levanoni, Oded; Audet, Joachim; Carlson, Peter; Eklöf, Karin; Hartman, Göran; McKie, Brendan; Ledesma, José; Segersten, Joel; Truchy, Amélie; Futter, Martyn

    2017-11-01

    Globally, artificial river impoundment, nutrient enrichment and biodiversity loss impair freshwater ecosystem integrity. Concurrently, beavers, ecosystem engineers recognized for their ability to construct dams and create ponds, are colonizing sites across the Holarctic after widespread extirpation in the 19th century, including areas outside their historical range. This has the potential to profoundly alter hydrology, hydrochemistry and aquatic ecology in both newly colonized and recolonized areas. To further our knowledge of the effects of beaver dams on aquatic environments, we extracted 1366 effect sizes from 89 studies on the impoundment of streams and lakes. Effects were assessed for 16 factors related to hydrogeomorphology, biogeochemistry, ecosystem functioning and biodiversity. Beaver dams affected concentrations of organic carbon in water, mercury in water and biota, sediment conditions and hydrological properties. There were no overall adverse effects caused by beaver dams or ponds on salmonid fish. Age was an important determinant of effect magnitude. While young ponds were a source of phosphorus, there was a tendency for phosphorus retention in older systems. Young ponds were a source methylmercury in water, but old ponds were not. To provide additional context, we also evaluated similarities and differences between environmental effects of beaver-constructed and artificial dams (767 effect sizes from 75 studies). Both are comparable in terms of effects on, for example, biodiversity, but have contrasting effects on nutrient retention and mercury. These results are important for assessing the role of beavers in enhancing and/or degrading ecological integrity in changing Holarctic freshwater systems.

  15. Beaver dams and channel sediment dynamics on Odell Creek, Centennial Valley, Montana, USA

    Science.gov (United States)

    Levine, Rebekah; Meyer, Grant A.

    2014-01-01

    Beaver dams in streams are generally considered to increase bed elevation through in-channel sediment storage, thus, reintroductions of beaver are increasingly employed as a restoration tool to repair incised stream channels. Here we consider hydrologic and geomorphic characteristics of the study stream in relation to in-channel sediment storage promoted by beaver dams. We also document the persistence of sediment in the channel following breaching of dams. Nine reaches, containing 46 cross-sections, were investigated on Odell Creek at Red Rock Lakes National Wildlife Refuge, Centennial Valley, Montana. Odell Creek has a snowmelt-dominated hydrograph and peak flows between 2 and 10 m3 s- 1. Odell Creek flows down a fluvial fan with a decreasing gradient (0.018-0.004), but is confined between terraces along most of its length, and displays a mostly single-thread, variably sinuous channel. The study reaches represent the overall downstream decrease in gradient and sediment size, and include three stages of beaver damming: (1) active; (2) built and breached in the last decade; and (3) undammed. In-channel sediment characteristics and storage were investigated using pebble counts, fine-sediment depth measurements, sediment mapping and surveys of dam breaches. Upstream of dams, deposition of fine (≤ 2 mm) sediment is promoted by reduced water surface slope, shear stress and velocity, with volumes ranging from 48 to 182 m3. High flows, however, can readily transport suspended sediment over active dams. Variations in bed-sediment texture and channel morphology associated with active dams create substantial discontinuities in downstream trends and add to overall channel heterogeneity. Observations of abandoned dam sites and dam breaches revealed that most sediment stored above beaver dams is quickly evacuated following a breach. Nonetheless, dam remnants trap some sediment, promote meandering and facilitate floodplain development. Persistence of beaver dam sediment

  16. Beaver dams, hydrological thresholds, and controlled floods as a management tool in a desert riverine ecosystem, Bill Williams River, Arizona

    Science.gov (United States)

    Andersen, D.C.; Shafroth, P.B.

    2010-01-01

    Beaver convert lotic stream habitat to lentic through dam construction, and the process is reversed when a flood or other event causes dam failure. We investigated both processes on a regulated Sonoran Desert stream, using the criterion that average current velocity is beaver pond length (determined by the upstream lentic-lotic boundary position) to dam size, and coupling that to the dam-size frequency distribution and repeated censuses of dams along the 58-km river. The ratio fell from 19:1 when no beaver dams were present to beaver. We investigated the dam failure-flood intensity relationship in three independent trials (experimental floods) featuring peak discharge ranging from 37 to 65 m3 s-1. Major damage (breach ??? 3-m wide) occurred at ??? 20% of monitored dams (n = 7-86) and a similar or higher proportion was moderately damaged. We detected neither a relationship between dam size and damage level nor a flood discharge threshold for initiating major damage. Dam constituent materials appeared to control the probability of major damage at low (attenuated) flood magnitude. We conclude that environmental flows prescribed to sustain desert riparian forest will also reduce beaver-created lentic habitat in a non-linear manner determined by both beaver dam and flood attributes. Consideration of both desirable and undesirable consequences of ecological engineering by beaver is important when optimizing environmental flows to meet ecological and socioeconomic goals. ?? 2010 John Wiley & Sons, Ltd.

  17. 75 FR 25876 - Notice of Intent To Prepare Resource Management Plans for the Beaver Dam Wash and Red Cliffs...

    Science.gov (United States)

    2010-05-10

    ... Intent To Prepare Resource Management Plans for the Beaver Dam Wash and Red Cliffs National Conservation... Environmental Impact Statement, Utah AGENCY: Bureau of Land Management, Interior. ACTION: Notice of intent..., intends to prepare Resource Management Plans (RMP) for the Beaver Dam Wash and the Red Cliffs National...

  18. Beaver dams, hydrological thresholds, and controlled floods as a management tool in a desert riverine ecosystem, Bill Williams River, Arizona

    Science.gov (United States)

    Andersen, D.C.; Shafroth, P.B.

    2010-01-01

    Beaver convert lotic stream habitat to lentic through dam construction, and the process is reversed when a flood or other event causes dam failure. We investigated both processes on a regulated Sonoran Desert stream, using the criterion that average current velocity is distribution and repeated censuses of dams along the 58-km river. The ratio fell from 19:1 when no beaver dams were present to probability of major damage at low (attenuated) flood magnitude. We conclude that environmental flows prescribed to sustain desert riparian forest will also reduce beaver-created lentic habitat in a non-linear manner determined by both beaver dam and flood attributes. Consideration of both desirable and undesirable consequences of ecological engineering by beaver is important when optimizing environmental flows to meet ecological and socioeconomic goals. ?? 2010 John Wiley & Sons, Ltd.

  19. Simulating the effects of a beaver dam on regional groundwater flow through a wetland

    OpenAIRE

    Kathleen Feiner; Christopher S. Lowry

    2015-01-01

    Study Focus: This research examines a wetland environment before and after the construction of a beaver dam to determine the hydrologic impacts on regional groundwater flow and quantify changes to the capture zone of a wetland pond. Increased hydraulic head behind a newly built beaver dam can cause shifts in the capture zone of a wetland pond. Changes in groundwater flux, and the extent of both the capture and discharge zones of this wetland were examined with the use of a groundwater flow mo...

  20. Do beaver dams reduce habitat connectivity and salmon productivity in expansive river floodplains?

    Science.gov (United States)

    Malison, Rachel L; Kuzishchin, Kirill V; Stanford, Jack A

    2016-01-01

    Beaver have expanded in their native habitats throughout the northern hemisphere in recent decades following reductions in trapping and reintroduction efforts. Beaver have the potential to strongly influence salmon populations in the side channels of large alluvial rivers by building dams that create pond complexes. Pond habitat may improve salmon productivity or the presence of dams may reduce productivity if dams limit habitat connectivity and inhibit fish passage. Our intent in this paper is to contrast the habitat use and production of juvenile salmon on expansive floodplains of two geomorphically similar salmon rivers: the Kol River in Kamchatka, Russia (no beavers) and the Kwethluk River in Alaska (abundant beavers), and thereby provide a case study on how beavers may influence salmonids in large floodplain rivers. We examined important rearing habitats in each floodplain, including springbrooks, beaver ponds, beaver-influenced springbrooks, and shallow shorelines of the river channel. Juvenile coho salmon dominated fish assemblages in all habitats in both rivers but other species were present. Salmon density was similar in all habitat types in the Kol, but in the Kwethluk coho and Chinook densities were 3-12× lower in mid- and late-successional beaver ponds than in springbrook and main channel habitats. In the Kol, coho condition (length: weight ratios) was similar among habitats, but Chinook condition was highest in orthofluvial springbrooks. In the Kwethluk, Chinook condition was similar among habitats, but coho condition was lowest in main channel versus other habitats (0.89 vs. 0.99-1.10). Densities of juvenile salmon were extremely low in beaver ponds located behind numerous dams in the orthofluvial zone of the Kwethluk River floodplain, whereas juvenile salmon were abundant in habitats throughout the entire floodplain in the Kol River. If beavers were not present on the Kwethluk, floodplain habitats would be fully interconnected and theoretically

  1. Dam busy: beavers and their influence on the structure and function of river systems

    Science.gov (United States)

    Larsen, J.; Larsen, A.; Lane, S. N.

    2017-12-01

    Beavers (Castor fiber, Castor canadensis) are the most influential mammalian ecosystem engineer, heavily modifying rivers and floodplains and influencing the hydrology, geomorphology, carbon and nutrient cycling, and ecology. They do this by constructing dams, digging canals and burrows, felling trees and introducing wood into streams, which in turn impounds water, raises shallow water tables, and alters the partitioning of the water balance, sediment transport and channel patters, biogeochemical cycling, and aquatic and terrestrial habitats. However, largely in the absence of predators, beaver numbers have been rapidly increasing throughout Europe since the 1980s, but also in parts of the US and South America, prompting a need to comprehensively review the current state of knowledge on how beavers influence the structure and function of river systems. Here, we synthesize the overall impacts on hydrology, geomorphology, biogeochemistry, and aquatic and terrestrial ecosystems. We then examine the key feedbacks and overlaps between these changes induced by beavers, finding that modifications to the longitudinal connectivity drive many key process feedbacks. However, the magnitude of these feedbacks is also heavily dependent on the landscape and climatic context, with the ability to promote lateral connectivity determining the extent of beaver impacts as stream order increases. Crucially, beavers shape a river corridor, introducing distinct processes and feedbacks that would have existed prior to the historical collapse of beaver populations. There is thus a need to adapt current river management and restoration practices such that they can accommodate and enhance the ecosystem engineering services provided by beavers. We summarize key knowledge gaps that remain in our understanding of beaver impacts, which help map an interdisciplinary future research agenda.

  2. Ecosystem experiment reveals benefits of natural and simulated beaver dams to a threatened population of steelhead (Oncorhynchus mykiss)

    Science.gov (United States)

    Bouwes, Nicolaas; Weber, Nicholas; Jordan, Chris E.; Saunders, W. Carl; Tattam, Ian A.; Volk, Carol; Wheaton, Joseph M.; Pollock, Michael M.

    2016-01-01

    Beaver have been referred to as ecosystem engineers because of the large impacts their dam building activities have on the landscape; however, the benefits they may provide to fluvial fish species has been debated. We conducted a watershed-scale experiment to test how increasing beaver dam and colony persistence in a highly degraded incised stream affects the freshwater production of steelhead (Oncorhynchus mykiss). Following the installation of beaver dam analogs (BDAs), we observed significant increases in the density, survival, and production of juvenile steelhead without impacting upstream and downstream migrations. The steelhead response occurred as the quantity and complexity of their habitat increased. This study is the first large-scale experiment to quantify the benefits of beavers and BDAs to a fish population and its habitat. Beaver mediated restoration may be a viable and efficient strategy to recover ecosystem function of previously incised streams and to increase the production of imperiled fish populations. PMID:27373190

  3. Fluvial wood function downstream of beaver versus man-made dams in headwater streams in Massachusetts, USA

    Science.gov (United States)

    David, G. C.; DeVito, L. F.; Munz, K. T.; Lisius, G.

    2014-12-01

    Fluvial wood is an essential component of stream ecosystems by providing habitat, increasing accumulation of organic matter, and increasing the processing of nutrients and other materials. However, years of channel alterations in Massachusetts have resulted in low wood loads despite the afforestation that has occurred since the early 1900s. Streams have also been impacted by a large density of dams, built during industrialization, and reduction of the beaver population. Beavers were reintroduced to Massachusetts in the 1940s and they have since migrated throughout the state. Beaver dams impound water, which traps sediment and results in the development of complex channel patterns and more ecologically productive and diverse habitats than those found adjacent to man-made dams. To develop better management practices for dam removal it is essential that we understand the geomorphic and ecologic function of wood in these channels and the interconnections with floodplain dynamics and stream water chemistry. We investigate the connections among fluvial wood, channel morphology, floodplain soil moisture dynamics, and stream water chemistry in six watersheds in Massachusetts that have been impacted by either beaver or man-made dams. We hypothesize that wood load will be significantly higher below beaver dams, subsequently altering channel morphology, water chemistry, and floodplain soil moisture. Reaches are surveyed up- and downstream of each type of dam to better understand the impact dams have on the fluvial system. Surveys include a longitudinal profile, paired with dissolved oxygen and ammonium measurements, cross-section and fluvial wood surveys, hydraulic measurements, and floodplain soil moisture mapping. We found that dissolved oxygen mirrored the channel morphology, but did not vary significantly between reaches. Wood loads were significantly larger downstream of beaver dams, which resulted in significant changes to the ammonium levels. Floodplain soil moisture

  4. Simulating the effects of a beaver dam on regional groundwater flow through a wetland

    Directory of Open Access Journals (Sweden)

    Kathleen Feiner

    2015-09-01

    New hydrological insights for the region: The construction of a beaver dam resulted in minimal changes to regional groundwater flow paths at this site, which is attributed to a clay unit underlying the peat, disconnecting this wetland from regional groundwater flow. However, groundwater discharge from the wetland pond increased by 90%. Simulating a scenario with the numerical model in which the wetland is connected to regional groundwater flow results in a much larger impact on flow paths. In the absence of the clay layer, the simulated construction of a beaver dam causes a 70% increase in groundwater discharge from the wetland pond and increases the surface area of both the capture zone and the discharge zone by 30% and 80%, respectively.

  5. Classification of the alterations of beaver dams to headwater streams in northeastern Connecticut, U.S.A.

    Science.gov (United States)

    Burchsted, Denise; Daniels, Melinda D.

    2014-01-01

    Of the many types of barriers to water flow, beaver dams are among the smallest, typically lasting less than a decade and rarely exceeding 1.5 m in height. They are also among the most frequent and common obstructions in rivers, with a density often exceeding ten dams per km, a frequency of construction within a given network on a time scale of years, and a historic extent covering most of North America. Past quantification of the geomorphologic impact of beaver dams has primarily been limited to local impacts within individual impoundments and is of limited geographic scope. To assess the impact of beaver dams at larger scales, this study examines channel shape and sediment distribution in thirty river reaches in northeastern Connecticut, U.S.A. The study reaches fall within the broader categories of impounded and free-flowing segments, leaving a third segment class of beaver meadows requiring additional study. Each of the study reaches were classified at the reach scale as free-flowing, valley-wide beaver pond, in-channel beaver pond, and downstream of beaver dam. The bankfull channel width to depth ratios and channel widths normalized by watershed area vary significantly across the study reach classes. Additionally, reaches modified by beaver dams have finer sediment distributions. This paper provides the first quantitative geomorphic descriptions of the in-channel beaver pond and reaches downstream of beaver dams. Given the different channel shapes and sediment distributions, we infer that geomorphic processes are longitudinally decoupled by these frequent barriers that control local base level. These barriers generate heterogeneity within a river network by greatly increasing the range of channel morphology and by generating patches controlled by different processes. Therefore, in spite of the small size of individual beaver dams, the cumulative effect of multiple dams has the potential to modify processes at larger spatial scales. To improve assessment of the

  6. Effect of beaver dams on the hydrology of small mountain streams: Example from the Chevral in the Ourthe Orientale basin, Ardennes, Belgium

    Science.gov (United States)

    Nyssen, J.; Pontzeele, J.; Billi, P.

    2011-05-01

    SummaryThe European beaver ( Castor fiber) was recently reintroduced to Belgium, after an absence of more than 150 years; around 120 beaver dam systems have been established. In Europe, few studies consider the hydrological effects of those dams, and the spatial scale larger than that of one beaver pond system has not been addressed at all. This research focuses on the hydrological effects of a series of six beaver dams on the Chevral R., a second order tributary of the Ourthe Orientale R. in a forested area of the Ardennes. Thereby, also the Ourthe Orientale sub-basin itself was taken into account, being the area with probably the highest density of beaver dams in Belgium. The main research questions regarded: (1) the extent to which discharge peaks are reduced at the very location and well downstream of beaver dams and (2) the impact of the beaver dams on low flows. The first approach consisted of a temporal analysis of the Ourthe Orientale discharge and precipitation data for the periods 1978-2003 (before) and 2004-2009 (after the establishment of beaver dams in the sub-basin). The second study determined the in situ impact of the beaver dams: discharges were measured (September 2009-March 2010) upstream as well as downstream of the 0.52 ha beaver dam system on the Chevral river, and changes in water level within the system of six dams were monitored. Our findings indicate that there is a significant lowering of discharge peaks in the downstream river reaches due to the effect of the beaver dams. The temporal analysis of the Ourthe Orientale sub-basin shows an increase in the recurrence interval for major floods; for instance, the recurrence interval of a reference flood of 60 m 3 s -1 increased from 3.4 years to 5.6 years since the establishment of the beaver dams. At the scale of the Chevral beaver dams' site, we measured that the dams top off the peak flows, in addition delaying them by approximately 1 day. There are also increased low flows: Q355 (i.e. the

  7. Relating hyporheic fluxes, residence times, and redox-sensitive biogeochemical processes upstream of beaver dams

    Science.gov (United States)

    Briggs, Martin A.; Lautz, Laura; Hare, Danielle K.

    2013-01-01

    Abstract. Small dams enhance the development of patchy microenvironments along stream corridors by trapping sediment and creating complex streambed morphologies. This patchiness drives intricate hyporheic flux patterns that govern the exchange of O2 and redox-sensitive solutes between the water column and the stream bed. We used multiple tracer techniques, naturally occurring and injected, to evaluate hyporheic flow dynamics and associated biogeochemical cycling and microbial reactivity around 2 beaver dams in Wyoming (USA). High-resolution fiber-optic distributed temperature sensing was used to collect temperature data over 9 vertical streambed profiles and to generate comprehensive vertical flux maps using 1-dimensional (1-D) heat-transport modeling. Coincident with these locations, vertical profiles of hyporheic water were collected every week and analyzed for dissolved O2, pH, dissolved organic C, and several conservative and redox-sensitive solutes. In addition, hyporheic and net stream aerobic microbial reactivity were analyzed with a constant-rate injection of the biologically sensitive resazurin (Raz) smart tracer. The combined results revealed a heterogeneous system with rates of downwelling hyporheic flow organized by morphologic unit and tightly coupled to the redox conditions of the subsurface. Principal component analysis was used to summarize the variability of all redox-sensitive species, and results indicated that hyporheic water varied from oxic-stream-like to anoxic-reduced in direct response to the hydrodynamic conditions and associated residence times. The anaerobic transition threshold predicted by the mean O2 Damko

  8. Characterisation of Beaver Habitat Parameters That Promote the Use of Culverts as Dam Construction Sites: Can We Limit the Damage to Forest Roads?

    Directory of Open Access Journals (Sweden)

    Geneviève Tremblay

    2017-12-01

    Full Text Available The use of forest roads as foundations for dam construction by beavers is a recurrent problem in the management of forest road networks. In order to limit the damage to forest roads, our goal was to calculate the probability of beaver dam installation on culverts, according to surrounding habitat parameters, which could allow for improvement in the spatial design of new roads that minimise conflicts with beavers. Comparisons of culverts with (n = 77 and without (n = 51 dams in northwestern Quebec showed that catchment surface, cumulate length of all local streams within a 2-km radius, and road embankment height had a negative effect on the probability of dam construction on culverts, while flow level and culvert diameter ratio had a positive effect. Nevertheless, predicted probabilities of dam construction on culverts generally exceeded 50%, even on sites that were less favourable to beavers. We suggest that it would be more reasonable to take their probable subsequent presence into account at the earliest steps of road conception. Installing mitigation measures such as pre-dams during road construction would probably reduce the occurrence of conflicts with beavers and thus reduce the maintenance costs of forest roads.

  9. Dam-to-offspring transmission and persistence of Staphylococcus pseudintermedius clones within dog families

    DEFF Research Database (Denmark)

    Paul, Narayan Chandra; Damborg, Peter Panduro; Guardabassi, Luca

    2014-01-01

    Staphylococcus pseudintermedius is an opportunistic pathogen that causes mainly skin infections in dogs. Although vertical transmission of S. pseudintermedius strains from dam to offspring has been reported, the persistence of the dam's strains in offspring over long periods of time is virtually ...

  10. Topics on distance correlation, feature screening and lifetime expectancy with application to Beaver Dam eye study data

    Science.gov (United States)

    Kong, Jing

    This thesis includes 4 pieces of work. In Chapter 1, we present the work with a method for examining mortality as it is seen to run in families, and lifestyle factors that are also seen to run in families, in a subpopulation of the Beaver Dam Eye Study that has died by 2011. We find significant distance correlations between death ages, lifestyle factors, and family relationships. Considering only sib pairs compared to unrelated persons, distance correlation between siblings and mortality is, not surprisingly, stronger than that between more distantly related family members and mortality. Chapter 2 introduces a feature screening procedure with the use of distance correlation and covariance. We demonstrate a property for distance covariance, which is incorporated in a novel feature screening procedure based on distance correlation as a stopping criterion. The approach is further implemented to two real examples, namely the famous small round blue cell tumors data and the Cancer Genome Atlas ovarian cancer data Chapter 3 pays attention to the right censored human longevity data and the estimation of lifetime expectancy. We propose a general framework of backward multiple imputation for estimating the conditional lifetime expectancy function and the variance of the estimator in the right censoring setting and prove the properties of the estimator. In addition, we apply the method to the Beaver Dam eye study data to study human longevity, where the expected human lifetime are modeled with smoothing spline ANOVA based on the covariates including baseline age, gender, lifestyle factors and disease variables. Chapter 4 compares two imputation methods for right censored data, namely the famous Buckley-James estimator and the backward imputation method proposed in Chapter 3 and shows that backward imputation method is less biased and more robust with heterogeneity.

  11. Beaver assisted river valley formation

    Science.gov (United States)

    Westbrook, Cherie J.; Cooper, D.J.; Baker, B.W.

    2011-01-01

    We examined how beaver dams affect key ecosystem processes, including pattern and process of sediment deposition, the composition and spatial pattern of vegetation, and nutrient loading and processing. We provide new evidence for the formation of heterogeneous beaver meadows on riverine system floodplains and terraces where dynamic flows are capable of breaching in-channel beaver dams. Our data show a 1.7-m high beaver dam triggered overbank flooding that drowned vegetation in areas deeply flooded, deposited nutrient-rich sediment in a spatially heterogeneous pattern on the floodplain and terrace, and scoured soils in other areas. The site quickly de-watered following the dam breach by high stream flows, protecting the deposited sediment from future re-mobilization by overbank floods. Bare sediment either exposed by scouring or deposited by the beaver flood was quickly colonized by a spatially heterogeneous plant community, forming a beaver meadow. Many willow and some aspen seedlings established in the more heavily disturbed areas, suggesting the site may succeed to a willow carr plant community suitable for future beaver re-occupation. We expand existing theory beyond the beaver pond to include terraces within valleys. This more fully explains how beavers can help drive the formation of alluvial valleys and their complex vegetation patterns as was first postulated by Ruedemann and Schoonmaker in 1938. ?? 2010 John Wiley & Sons, Ltd.

  12. Transfer of Ga-67 from hamster dam to fetus and offspring

    International Nuclear Information System (INIS)

    Hayes, R.L.; Byrd, B.L.

    1981-01-01

    We have studied the transfer of Ga-67 from the hamster dam to the fetus and also to the postpartum offspring. During gestation the concentration of Ga-67 in the mammary glands increased by approximately 20-fold, and Ga-67 was transferred across the placenta into the fetus. The concentration of Ga-67 in the fetus decreased during the terminal stages of gestation, partly due to a decreased transfer of Ga-67 itself and partly as the result of the rapid growth of the fetus. One-day-old offspring were able to absorb from the gastrointestinal tract the Ga-67 contained in ingested dam's milk, whereas 9-day-old offspring excrete essentially all such ingested Ga-67. The Ga-67 radiation hazards to the fetus during gestation and that resulting from the transfer of Ga-67 to the newborn through ingestion of the mother's milk should receive further investigation

  13. Transfer of Ga-67 from hamster dam to fetus and offspring

    International Nuclear Information System (INIS)

    Hayes, R.L.; Byrd, B.L.

    1981-01-01

    The transfer of Ga-67 from the hamster dam to the fetus and to the postpartum offspring has been studied. During gestation the concentration of Ga-67 in the mammary glands increased by approximately 20-fold, and Ga-67 was transferred across the placenta into the fetus. The concentration of Ga-67 in the fetus decreased during the terminal stages of gestation, partly due to a decreased transfer of Ga-67 itself and partly as the result of the rapid growth of the fetus. One-day-old offspring were able to absorb from the gastrointestinal tract the Ga-67 contained in ingested dam's milk, whereas 9-day-old offspring excreted essentially all such ingested Ga-67. The Ga-67 radiation hazards to the fetus during gestation and that resulting from the transfer of Ga-67 to the newborn through ingestion of the mother's milk should receive further investigation

  14. Serum Phosphate and Retinal Microvascular Changes: The Multi-Ethnic Study of Atherosclerosis and the Beaver Dam Eye Study.

    Science.gov (United States)

    Mehta, Rupal; Hodakowski, Alexander; Cai, Xuan; Lee, Kris E; Kestenbaum, Bryan R; de Boer, Ian H; Fawzi, Amani; Wong, Tien Yin; Ix, Joachim; Klein, Barbara; Klein, Ronald; Isakova, Tamara

    2017-12-01

    Higher levels of serum phosphate are strongly linked to increased risk of cardiovascular disease and therapies aimed to lower serum phosphate are employed in the management of patients with chronic kidney disease (CKD). Data are limited, however, on serum phosphate as a risk factor for microvascular disease in community-based populations. It is important to determine the impact of novel risk factors, such as phosphate, on the microvasculature. We conducted a prospective study of 3919 individuals in the Multi-Ethnic Study of Atherosclerosis (MESA) and 3544 individuals in the Beaver Dam Eye Study (BDES) to test the associations of serum phosphate with retinopathy and retinal vessel caliber, and change in retinopathy severity and change in retinal vessel caliber. Mean (standard deviation) serum phosphate was 3.66 (0.52) mg/dl in the MESA and 3.77 (0.55) mg/dl in the BDES. In multivariable adjusted models, phosphate was significantly associated with prevalent retinopathy in the MESA (Odds Ratio [OR] per 1 mg/dl increase in phosphate, 1.22; Confidence Interval [CI] 1.02-1.47) and the BDES (OR 1.06; CI 1.01-1.11). In stratified analyses, these relationships were even stronger and only seen in individuals with diabetes in both the MESA (OR 1.81; CI 1.30-2.53) and the BDES (OR 1.16; CI 1.05-1.29). Phosphate was not associated with incident or change in retinopathy severity, nor any retinal caliber outcome. Among community-living individuals with low prevalence of CKD, higher serum phosphate was associated with prevalent retinopathy in individuals with diabetes. Further longitudinal assessments in patients with diabetes necessitate further investigation.

  15. Maternal postpartum learned helplessness (LH) affects maternal care by dams and responses to the LH test in adolescent offspring.

    Science.gov (United States)

    Kurata, Akiko; Morinobu, Shigeru; Fuchikami, Manabu; Yamamoto, Shigeto; Yamawaki, Shigeto

    2009-06-01

    It is known that the early environment affects the mental development of rodent and human offspring. However, it is not known specifically whether a postpartum depressive state influences the depressive state in offspring. Using learned helplessness (LH) in rats as an animal model of depression, we examined the influence of maternal postpartum LH on responses to the LH test of offspring. Dam rats were judged as LH or non-helpless (nLH) on postnatal days (PN) 2-3, and maternal behavior was recorded during PN2-14. On PN 45-46, offspring were subjected to the LH test. Plasma corticosterone (CORT) levels, hippocampal levels of glucocorticoid receptor (GR) and brain-derived neurotrophic factor (BDNF) mRNA were measured before and after the LH test in offspring. Active nursing in LH dams was significantly lower than that in nLH dams. Susceptibility to LH in the offspring of LH dams was significantly higher than in those of nLH dams, and was negatively correlated with active nursing by LH dams. The GR mRNA levels before and after the LH test were lower in the offspring of LH dams than in those of nLH dams, and the reduced basal GR mRNA and protein might have resulted in the higher CORT response after the LH test. There was no significant difference in BDNF mRNA in the offspring of LH and nLH dams. These findings suggest that early postpartum LH decreased active nursing and increased depression-like behavior in the adolescent offspring via dysfunction of the hypothalamic-pituitary-adrenal axis.

  16. Can Viral Videos Help Beaver Restore Streams?

    Science.gov (United States)

    Castro, J. M.; Pollock, M. M.; Lewallen, G.; Jordan, C.; Woodruff, K.

    2015-12-01

    Have you watched YouTube lately? Did you notice the plethora of cute animal videos? Researchers, including members of our Beaver Restoration Research team, have been studying the restoration potential of beaver for decades, yet in the past few years, beaver have gained broad acclaim and some much deserved credit for restoration of aquatic systems in North America. Is it because people can now see these charismatic critters in action from the comfort of their laptops? While the newly released Beaver Restoration Guidebook attempts to answer many questions, sadly, this is not one of them. We do, however, address the use of beaver (Castor canadensis) in stream, wetland, and floodplain restoration and discuss the many positive effects of beaver on fluvial ecosystems. Our team, composed of researchers from NOAA National Marine Fisheries Service, US Fish and Wildlife Service, US Forest Service, and Portland State University, has developed a scientifically rigorous, yet accessible, practitioner's guide that provides a synthesis of the best available science for using beaver to improve ecosystem functions. Divided into two broad sections -- Beaver Ecology and Beaver Restoration and Management -- the guidebook focuses on the many ways in which beaver improve habitat, primarily through the construction of dams that impound water and retain sediment. In Beaver Ecology, we open with a discussion of the general effects that beaver dams have on physical and biological processes, and we close with "Frequently Asked Questions" and "Myth Busters". In Restoration and Management, we discuss common emerging restoration techniques and methods for mitigating unwanted beaver effects, followed by case studies from pioneering practitioners who have used many of these beaver restoration techniques in the field. The lessons they have learned will help guide future restoration efforts. We have also included a comprehensive beaver ecology library of over 1400 references from scientific journals

  17. Maternal Western diet increases adiposity even in male offspring of obesity-resistant rat dams: early endocrine risk markers.

    Science.gov (United States)

    Frihauf, Jennifer B; Fekete, Éva M; Nagy, Tim R; Levin, Barry E; Zorrilla, Eric P

    2016-12-01

    Maternal overnutrition or associated complications putatively mediate the obesogenic effects of perinatal high-fat diet on developing offspring. Here, we tested the hypothesis that a Western diet developmental environment increases adiposity not only in male offspring from obesity-prone (DIO) mothers, but also in those from obesity-resistant (DR) dams, implicating a deleterious role for the Western diet per se. Selectively bred DIO and DR female rats were fed chow (17% kcal fat) or Western diet (32%) for 54 days before mating and, thereafter, through weaning. As intended, despite chow-like caloric intake, Western diet increased prepregnancy weight gain and circulating leptin levels in DIO, but not DR, dams. Yet, in both genotypes, maternal Western diet increased the weight and adiposity of preweanlings, as early as in DR offspring, and increased plasma leptin, insulin, and adiponectin of weanlings. Although body weight normalized with chow feeding during adolescence, young adult Western diet offspring subsequently showed decreased energy expenditure and, in DR offspring, decreased lipid utilization as a fuel substrate. By mid-adulthood, maternal Western diet DR offspring ate more chow, weighed more, and were fatter than controls. Thus, maternal Western diet covertly programmed increased adiposity in childhood and adulthood, disrupted relations of energy regulatory hormones with body fat, and decreased energy expenditure in offspring of lean, genetically obesity-resistant mothers. Maternal Western diet exposure alone, without maternal obesity or overnutrition, can promote offspring weight gain. Copyright © 2016 Frihauf et al.

  18. Female Offspring From Chronic Hyperandrogenemic Dams Exhibit Delayed Puberty and Impaired Ovarian Reserve.

    Science.gov (United States)

    Wang, Zhiqiang; Shen, Mingjie; Xue, Ping; DiVall, Sara A; Segars, James; Wu, Sheng

    2018-02-01

    Female offspring of many species exposed to high doses of androgens in utero experience endocrine dysfunction during adulthood. The phenotype of offspring from females with prepregnancy hyperandrogenemia and impaired ovulation, however, has not been examined. We developed a mouse model of hyperandrogenemia by implanting a low-dose dihydrotestosterone (DHT) pellet 15 days before conception. Female offspring born to dams with hyperandrogenemia (DHT daughters) had delayed puberty (P DHT (non-DHT daughters, PND37.5). Serum follicle-stimulating hormone (FSH) levels in the DHT daughters were fourfold higher (P DHT daughters (controls). DHT daughters showed an extended time in metestrus/diestrus and a shorter time in the proestrus/estrus phase compared with non-DHT daughters (P DHT daughters compared with non-DHT daughters (P DHT daughters compared with non-DHT daughters. Daughters from hyperandrogenemic females exhibited elevated prepubertal FSH levels, diminished ovarian response to superovulation, impaired estrous cyclicity, delayed onset of puberty, and reduced ovarian reserve, suggesting that fetal androgen exposure had lasting effects on female reproductive function. Copyright © 2018 Endocrine Society.

  19. Unlimited access to low-energy diet causes acute malnutrition in dams and alters biometric and biochemical parameters in offspring.

    Science.gov (United States)

    do Nascimento, E; de Santana Muniz, G; das Graças de Santana Muniz, M; de Souza Alexandre, L; da Rocha, L S; Leandro, C G; de Castro, R M; Bolaños-Jimenez, F

    2014-02-01

    Here we analyze the outcomes of unlimited access to a low-energy (LE) diet in dams and their offspring. At 3 weeks' gestation, pregnant Wistar rats were divided into two groups: (1) the control group received a normoenergetic diet; and (2) the experimental group received the LE diet. In dams, lactation outcomes, food intake, body weight, plasma IGF-1, prealbumin, transferrin and retinol-binding protein levels were evaluated; in offspring, biometric and biochemical parameters and food intake were evaluated. No differences were observed during pregnancy. However, after lactation, dams that received the LE diet demonstrated significant reductions in body weight (P<0.05), plasma IGF-1 (P=0.01), prealbumin and visceral fat (P<0.001). Pups born to dams that received the LE diet demonstrated reduced body length and weight at weaning (P<0.001) and were lighter than the control animals at the end of the experimental period. Pups also demonstrated reduced plasma, low-density lipoprotein (P=0.04), triglycerides (P=0.002) and glucose levels (P<0.05), and differences were noted in visceral fat. These results indicate that feeding dams with LE diet during the reproductive period induces acute malnutrition and impairs the growth and development of offspring, as well as certain metabolic parameters.

  20. Experimentally induced gestational androgen excess disrupts glucoregulation in rhesus monkey dams and their female offspring.

    Science.gov (United States)

    Abbott, David H; Bruns, Cristin R; Barnett, Deborah K; Dunaif, Andrea; Goodfriend, Theodore L; Dumesic, Daniel A; Tarantal, Alice F

    2010-11-01

    Discrete fetal androgen excess during early gestation in rhesus monkeys (Macaca mulatta) promotes endocrine antecedents of adult polycystic ovary syndrome (PCOS)-like traits in female offspring. Because developmental changes promoting such PCOS-like metabolic dysfunction remain unclear, the present study examined time-mated, gravid rhesus monkeys with female fetuses, of which nine gravid females received 15 mg of testosterone propionate (TP) subcutaneously daily from 40 to 80 days (first to second trimesters) of gestation [term, mean (range): 165 (155-175) days], whereas an additional six such females received oil vehicle injections over the same time interval. During gestation, ultrasonography quantified fetal growth measures and was used as an adjunct for fetal blood collections. At term, all fetuses were delivered by cesarean section for postnatal studies. Blood samples were collected from dams and infants for glucose, insulin, and total free fatty acid (FFA) determinations. TP injections transiently accelerated maternal weight gain in dams, very modestly increased head diameter of prenatally androgenized (PA) fetuses, and modestly increased weight gain in infancy compared with concurrent controls. Mild to moderate glucose intolerance, with increased area-under-the-curve circulating insulin values, occurred in TP-injected dams during an intravenous glucose tolerance test in the early second trimester. Moreover, reduced circulating FFA levels occurred in PA fetuses during a third trimester intravenous glucagon-tolbutamide challenge (140 days gestation), whereas excessive insulin sensitivity and increased insulin secretion relative to insulin sensitivity occurred in PA infants during an intravenous glucose-tolbutamide test at ∼1.5 mo postnatal age. Data from these studies suggest that experimentally induced fetal androgen excess may result in transient hyperglycemic episodes in the intrauterine environment that are sufficient to induce relative increases in

  1. The Beaver: A Marine Education Infusion Unit. Northern New England Marine Education Project.

    Science.gov (United States)

    Maine Univ., Orono. Coll. of Education.

    This interdisciplinary unit is intended for use with third grade classes. It examines the history and economics of man's relationships to the beaver. It investigates the natural history of the beaver, its anatomy, range, food sources, and the skills it employs to modify its environment by building dams. The structure of beaver dams is examined.…

  2. Effects of disturbed liver growth and oxidative stress of high-fat diet-fed dams on cholesterol metabolism in offspring mice.

    Science.gov (United States)

    Kim, Juyoung; Kim, Juhae; Kwon, Young Hye

    2016-08-01

    Changes in nutritional status during gestation and lactation have detrimental effects on offspring metabolism. Several animal studies have shown that maternal high-fat diet (HFD) can predispose the offspring to development of obesity and metabolic diseases, however the mechanisms underlying these transgenerational effects are poorly understood. Therefore, we examined the effect of maternal HFD consumption on metabolic phenotype and hepatic expression of involved genes in dams to determine whether any of these parameters were associated with the metabolic outcomes in the offspring. Female C57BL/6 mice were fed a low-fat diet (LFD: 10% calories from fat) or a high-fat diet (HFD: 45% calories from fat) for three weeks before mating, and during pregnancy and lactation. Dams and their male offspring were studied at weaning. Dams fed an HFD had significantly higher body and adipose tissue weights and higher serum triglyceride and cholesterol levels than dams fed an LFD. Hepatic lipid levels and mRNA levels of genes involved in lipid metabolism, including LXRα, SREBP-2, FXR, LDLR, and ABCG8 were significantly changed by maternal HFD intake. Significantly lower total liver DNA and protein contents were observed in dams fed an HFD, implicating the disturbed liver adaptation in the pregnancy-related metabolic demand. HFD feeding also induced significant oxidative stress in serum and liver of dams. Offspring of dams fed an HFD had significantly higher serum cholesterol levels, which were negatively correlated with liver weights of dams and positively correlated with hepatic lipid peroxide levels in dams. Maternal HFD consumption induced metabolic dysfunction, including altered liver growth and oxidative stress in dams, which may contribute to the disturbed cholesterol homeostasis in the early life of male mice offspring.

  3. Methyl donor supplementation alters cognitive performance and motivation in female offspring from high-fat diet-fed dams.

    Science.gov (United States)

    McKee, Sarah E; Grissom, Nicola M; Herdt, Christopher T; Reyes, Teresa M

    2017-06-01

    During gestation, fetal nutrition is entirely dependent on maternal diet. Maternal consumption of excess fat during pregnancy has been linked to an increased risk of neurologic disorders in offspring, including attention deficit/hyperactivity disorder, autism, and schizophrenia. In a mouse model, high-fat diet (HFD)-fed offspring have cognitive and executive function deficits as well as whole-genome DNA and promoter-specific hypomethylation in multiple brain regions. Dietary methyl donor supplementation during pregnancy or adulthood has been used to alter DNA methylation and behavior. Given that extensive brain development occurs during early postnatal life-particularly within the prefrontal cortex (PFC), a brain region critical for executive function-we examined whether early life methyl donor supplementation ( e.g., during adolescence) could ameliorate executive function deficits observed in offspring that were exposed to maternal HFD. By using operant testing, progressive ratio, and the PFC-dependent 5-choice serial reaction timed task (5-CSRTT), we determined that F1 female offspring (B6D2F1/J) from HFD-fed dams have decreased motivation (decreased progressive ratio breakpoint) and require a longer stimulus length to complete the 5-CSRTT task successfully, whereas early life methyl donor supplementation increased motivation and shortened the minimum stimulus length required for a correct response in the 5-CSRTT. Of interest, we found that expression of 2 chemokines, CCL2 and CXCL10, correlated with the median stimulus length in the 5-CSRTT. Furthermore, we found that acute adult supplementation of methyl donors increased motivation in HFD-fed offspring and those who previously received supplementation with methyl donors. These data point to early life as a sensitive time during which dietary methyl donor supplementation can alter PFC-dependent cognitive behaviors.-McKee, S. E., Grissom, N. M., Herdt, C. T., Reyes, T. M. Methyl donor supplementation alters

  4. Methyl donor supplementation alters cognitive performance and motivation in female offspring from high-fat diet–fed dams

    Science.gov (United States)

    McKee, Sarah E.; Grissom, Nicola M.; Herdt, Christopher T.; Reyes, Teresa M.

    2017-01-01

    During gestation, fetal nutrition is entirely dependent on maternal diet. Maternal consumption of excess fat during pregnancy has been linked to an increased risk of neurologic disorders in offspring, including attention deficit/hyperactivity disorder, autism, and schizophrenia. In a mouse model, high-fat diet (HFD)–fed offspring have cognitive and executive function deficits as well as whole-genome DNA and promoter-specific hypomethylation in multiple brain regions. Dietary methyl donor supplementation during pregnancy or adulthood has been used to alter DNA methylation and behavior. Given that extensive brain development occurs during early postnatal life—particularly within the prefrontal cortex (PFC), a brain region critical for executive function—we examined whether early life methyl donor supplementation (e.g., during adolescence) could ameliorate executive function deficits observed in offspring that were exposed to maternal HFD. By using operant testing, progressive ratio, and the PFC-dependent 5-choice serial reaction timed task (5-CSRTT), we determined that F1 female offspring (B6D2F1/J) from HFD-fed dams have decreased motivation (decreased progressive ratio breakpoint) and require a longer stimulus length to complete the 5-CSRTT task successfully, whereas early life methyl donor supplementation increased motivation and shortened the minimum stimulus length required for a correct response in the 5-CSRTT. Of interest, we found that expression of 2 chemokines, CCL2 and CXCL10, correlated with the median stimulus length in the 5-CSRTT. Furthermore, we found that acute adult supplementation of methyl donors increased motivation in HFD-fed offspring and those who previously received supplementation with methyl donors. These data point to early life as a sensitive time during which dietary methyl donor supplementation can alter PFC-dependent cognitive behaviors.—McKee, S. E., Grissom, N. M., Herdt, C. T., Reyes, T. M. Methyl donor supplementation

  5. A Calcium-Deficient Diet in Rat Dams during Gestation Decreases HOMA-β% in 3 Generations of Offspring.

    Science.gov (United States)

    Takaya, Junji; Yamanouchi, Sohsaku; Tanabe, Yuko; Kaneko, Kazunari

    2016-01-01

    Prenatal malnutrition can affect the phenotype of offspring by altering epigenetic regulation. Calcium (Ca) plays an important role in the pathogenesis of insulin resistance syndrome. We hypothesized that a Ca-deficient diet during pregnancy would alter insulin resistance and secretion in more than 1 generation of offspring. Female Wistar rats consumed either a Ca-deficient or a control diet ad libitum from 3 weeks before conception to 21 days after parturition and were mated with control males. Randomly selected F1 and F2 females were mated with males of each generation on postnatal day 70. The F1 and F2 dams were fed a control diet ad libitum during pregnancy and lactation. All offspring were fed a control diet starting at the time of weaning and were sacrificed on day 180. HOMA-β% decreased in F1 through F3, and levels in F2 and F3 males and females were significantly lower than in controls. The mean levels of insulin and HOMA-IR were higher in F1 males but lower in F3 males than in control males. The HOMA-IR did not differ between any of the female offspring and controls. Maternal Ca restriction during pregnancy and/or lactation influences insulin secretion in 3 generations of offspring. © 2017 S. Karger AG, Basel.

  6. Dams

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset �is generated from from the Vermont Dam Inventory (VDI). The VDI is managed by the VT DEC's Dam Safety and Hydrology Section and contains information...

  7. Seventh International Beaver Symposium

    OpenAIRE

    Yuri A. Gorshkov

    2016-01-01

    The paper presents data on the seventh international Beaver Symposium. Brief historical background about previous Beaver Symposia beaver is shown. Data on the sections of symposium, number of participants and reports are presented.

  8. Seventh International Beaver Symposium

    Directory of Open Access Journals (Sweden)

    Yuri A. Gorshkov

    2016-05-01

    Full Text Available The paper presents data on the seventh international Beaver Symposium. Brief historical background about previous Beaver Symposia beaver is shown. Data on the sections of symposium, number of participants and reports are presented.

  9. Beaver Mediated Water Table Dynamics in Mountain Peatlands

    Science.gov (United States)

    Karran, D. J.; Westbrook, C.; Bedard-Haughn, A.

    2016-12-01

    Water table dynamics play an important role in the ecological and biogeochemical processes that regulate carbon and water storage in peatlands. Beaver are common in these habitats and the dams they build have been shown to raise water tables in other environments. However, the impact of beaver dams in peatlands, where water tables rest close to the surface, has yet to be determined. We monitored a network of 50 shallow wells in a Canadian Rocky Mountain peatland for 6 years. During this period, a beaver colony was maintaining a number of beaver ponds for four years until a flood event removed the colony from the area and breached some of the dams. Two more years of data were collected after the flood event to assess whether the dams enhanced groundwater storage. Beaver dams raised water tables just as they do in other environments. Furthermore, water tables within 100 meters of beaver dams were more stable than those further away and water table stability overall was greater before the flood event. Our results suggest the presence/absence of beaver in peatlands has implications for groundwater water storage and overall system function.

  10. Where and How Wolves (Canis lupus Kill Beavers (Castor canadensis.

    Directory of Open Access Journals (Sweden)

    Thomas D Gable

    Full Text Available Beavers (Castor canadensis can be a significant prey item for wolves (Canis lupus in boreal ecosystems due to their abundance and vulnerability on land. How wolves hunt beavers in these systems is largely unknown, however, because observing predation is challenging. We inferred how wolves hunt beavers by identifying kill sites using clusters of locations from GPS-collared wolves in Voyageurs National Park, Minnesota. We identified 22 sites where wolves from 4 different packs killed beavers. We classified these kill sites into 8 categories based on the beaver-habitat type near which each kill occurred. Seasonal variation existed in types of kill sites as 7 of 12 (58% kills in the spring occurred at sites below dams and on shorelines, and 8 of 10 (80% kills in the fall occurred near feeding trails and canals. From these kill sites we deduced that the typical hunting strategy has 3 components: 1 waiting near areas of high beaver use (e.g., feeding trails until a beaver comes near shore or ashore, 2 using vegetation, the dam, or other habitat features for concealment, and 3 immediately attacking the beaver, or ambushing the beaver by cutting off access to water. By identifying kill sites and inferring hunting behavior we have provided the most complete description available of how and where wolves hunt and kill beavers.

  11. Renal Development and Blood Pressure in Offspring from Dams Submitted to High-Sodium Intake during Pregnancy and Lactation

    Directory of Open Access Journals (Sweden)

    Terezila M. Coimbra

    2012-01-01

    Full Text Available Exposure to an adverse environment in utero appears to programme physiology and metabolism permanently, with long-term consequences for health of the fetus or offspring. It was observed that the offspring from dams submitted to high-sodium intake during pregnancy present disturbances in renal development and in blood pressure. These alterations were associated with lower plasma levels of angiotensin II (AII and changes in renal AII receptor I (AT1 and mitogen-activated protein kinase (MAPK expressions during post natal kidney development. Clinical and experimental evidence show that the renin-angiotensin system (RAS participates in renal development. Many effects of AII are mediated through MAPK pathways. Extracellular signal-regulated protein kinases (ERKs play a pivotal role in cellular proliferation and differentiation. In conclusion, high-sodium intake during pregnancy and lactation can provoke disturbances in renal development in offspring leading to functional and structural alterations that persist in adult life. These changes can be related at least in part with the decrease in RAS activity considering that this system has an important role in renal development.

  12. Triclosan exposure reduces thyroxine levels in pregnant and lactating rat dams and in directly exposed offspring

    DEFF Research Database (Denmark)

    Petersen, Marta Axelstad; Boberg, Julie; Vinggaard, Anne Marie

    2013-01-01

    Thyroid disrupting chemicals can potentially disrupt brain development. Two studies investigating the effect of the antibacterial compound triclosan on thyroxine (T4) levels in rats are reported. In the first, Wistar rat dams were gavaged with 75, 150 or 300 mg triclosan/kg bw/day throughout gest...

  13. Feeding Chromonaela odorata during pregnancy to goat dams affects acceptance of this feedstuff by their offspring

    NARCIS (Netherlands)

    Hai, P.V.; Everts, H.; Tien, van D.; Schonewille, J.T.; Hendriks, W.H.

    2012-01-01

    We investigated the effect of Chromonaela odorata ingestion by goat dams during pregnancy on intake of C. odorata by their kids. Alteration of prenatal feed preference may be used to increase feed intake of novel feeds and the transit from outdoor to indoor goat farming in Vietnam. Ten female goats

  14. Comparison of muscle fibre characteristics and production traits among offspring from Meishan dams mated to different sires

    Directory of Open Access Journals (Sweden)

    Ki-Chang Hong

    2010-01-01

    Full Text Available This study evaluated how various porcine sires affected muscle fibre characteristics, with respect to production traits. Sires from Berkshire, Duroc, Meishan, and Yorkshire pigs were mated to Meishan dams (BM, DM, MM, and YM offspring, respectively. A total of 96 pigs were evaluated for muscle fibre characteristics and production traits. The progeny from Duroc and Yorkshire sires had the greatest number of total fibres (P<0.05 and exhibited less backfat thickness (P<0.001 and larger loin muscle areas (P<0.05 than BM pigs. The DM and BM crossbreds showed higher marbling (P<0.01, and colour scores (P<0.05, as well as lower shear force scores (P<0.001. The MM pigs had greater proportional area of type IIb muscle fibres (P<0.05, and also displayed higher drip loss (P<0.01, higher lightness (P<0.001, and a greater incidence of PSE pork (pale, soft, and exudative; 25% than DM, BM, and YM. These results showed that a greater number of total muscle fibres without increasing the cross sectional area of fibres improved lean meat production, and that a lower proportion of type IIb fibres was associated with better meat quality. For these reasons, the Duroc sire × Meishan dam crossbreed emerged as the most appropriate mating type examined herein to simultaneously enhance both lean meat production and meat quality.

  15. Maternal “junk-food” feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring

    Science.gov (United States)

    Ong, Z. Y.; Muhlhausler, B. S.

    2011-01-01

    Individuals exposed to high-fat, high-sugar diets before birth have an increased risk of obesity in later life. Recent studies have shown that these offspring exhibit increased preference for fat, leading to suggestions that perinatal exposure to high-fat, high-sugar foods results in permanent changes within the central reward system that increase the subsequent drive to overconsume palatable foods. The present study has determined the effect of a maternal “junk-food” diet on the expression of key components of the mesolimbic reward pathway in the offspring of rat dams at 6 wk and 3 mo of age. We show that offspring of junk-food-fed (JF) dams exhibit higher fat intake from weaning until at least 3 mo of age (males: 16±0.6 vs. 11±0.8 g/kg/d; females: 19±1.3 vs. 13±0.4 g/kg/d; Pjunk-food intake in postnatal life.—Ong, Z. Y., Muhlhausler, B. S. Maternal “junk-food” feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring. PMID:21427213

  16. Influence of maternal dietary n-3 fatty acids on breast milk and liver lipids of rat dams and offspring - a preliminary study

    DEFF Research Database (Denmark)

    Hartvigsen, M.S.; Mu, Huiling; Høy, Carl-Erik

    2003-01-01

    The impact of triacylglycerol (TAG) structure and level of n-3 fatty acids on the fatty acid profile of total breast milk lipids and total liver phospholipids (PL) of dams and offspring (1, 3 and 13 weeks of age), when administered during development, was examined. Pregnant rats were fed experime......The impact of triacylglycerol (TAG) structure and level of n-3 fatty acids on the fatty acid profile of total breast milk lipids and total liver phospholipids (PL) of dams and offspring (1, 3 and 13 weeks of age), when administered during development, was examined. Pregnant rats were fed...... experimental diets from the 8(th) day of pregnancy throughout lactation. After weaning and until 13 weeks of age, the offspring were fed the same diet as their dams. The experimental diets contained either a specific structured oil, linseed oil or fish oil. In the specific structured oil, a-linolenic acid (18...... fatty acids. Samples from three animals in each group were analyzed. The highest level of 22:6n-3 in the breast milk was obtained with diets containing this fatty acid itself. The fatty acid profile of rat dam liver PL was very different from the milk lipids indicating that the maternal dietary fats...

  17. [Detection of auditory impairment in the offsprings caused by drug treatment of the dams].

    Science.gov (United States)

    Kameyama, T; Nabeshima, T; Itoh, J

    1982-12-01

    To study the auditory impairment induced by prenatal administration of aminoglycosides in the offspring, the shuttle box method to measure the auditory threshold of rats (Kameyama et al., Folia pharmacol. japon. 77, 15, 1981) was employed. Four groups of pregnant rats were administered 200 mg/kg kanamycin sulfate (KM), 200 mg/kg dihydrostreptomycin sulfate (DHSM), 100 mg/kg neomycin sulfate (NM), or 1 ml/kg saline intramuscularly from the 10th to the 19th day of pregnancy. The auditory threshold of the offspring could be measured by the shuttle box method in about 90% of the live born rats at the age of 100 days. The auditory thresholds of the groups were as follows (mean +/- S.E.): saline group, 53.8 +/- 0.6 dB (N = 36); KM group, 63.8 +/- 1.1 dB (N = 34); DHSM group, 60.0 +/- 1.2 dB (N = 29); NM group, 62.4 +/- 1.2 dB (N = 24). Auditory thresholds of drug-treated groups were significantly higher than that of the saline group. However, no increase in the auditory threshold of the mother rat was detected after treatment with aminoglycosides. In addition, the experimental procedure of the shuttle box method is very easy, and the auditory threshold of a large number of rats could be measured in a short period. These findings suggest that this method is a very useful one for screening for auditory impairment induced by prenatal drug treatment in rat offspring.

  18. Rapid surface-water volume estimations in beaver ponds

    Science.gov (United States)

    Karran, Daniel J.; Westbrook, Cherie J.; Wheaton, Joseph M.; Johnston, Carol A.; Bedard-Haughn, Angela

    2017-02-01

    Beaver ponds are surface-water features that are transient through space and time. Such qualities complicate the inclusion of beaver ponds in local and regional water balances, and in hydrological models, as reliable estimates of surface-water storage are difficult to acquire without time- and labour-intensive topographic surveys. A simpler approach to overcome this challenge is needed, given the abundance of the beaver ponds in North America, Eurasia, and southern South America. We investigated whether simple morphometric characteristics derived from readily available aerial imagery or quickly measured field attributes of beaver ponds can be used to approximate surface-water storage among the range of environmental settings in which beaver ponds are found. Studied were a total of 40 beaver ponds from four different sites in North and South America. The simplified volume-area-depth (V-A-h) approach, originally developed for prairie potholes, was tested. With only two measurements of pond depth and corresponding surface area, this method estimated surface-water storage in beaver ponds within 5 % on average. Beaver pond morphometry was characterized by a median basin coefficient of 0.91, and dam length and pond surface area were strongly correlated with beaver pond storage capacity, regardless of geographic setting. These attributes provide a means for coarsely estimating surface-water storage capacity in beaver ponds. Overall, this research demonstrates that reliable estimates of surface-water storage in beaver ponds only requires simple measurements derived from aerial imagery and/or brief visits to the field. Future research efforts should be directed at incorporating these simple methods into both broader beaver-related tools and catchment-scale hydrological models.

  19. Exposure to the widely used fungicide Mancozeb causes thyroid hormone disruption in rat dams but no behavioral effects in the offspring

    DEFF Research Database (Denmark)

    Petersen, Marta Axelstad; Boberg, Julie; Nellemann, Christine Lydia

    2011-01-01

    The widely used fungicide Mancozeb has been shown to cause hypothyroxinemia and other adverse effects on the thyroid hormone system in adult experimental animals. In humans, hypothyroxinemia early in pregnancy is associated with adverse effects on the developing nervous system and can lead...... to impaired cognitive function and motor development in children. The aim of the present study was therefore to assess whether perinatal Mancozeb exposure would cause developmental neurotoxicity in rats. Groups of 9-21 time-mated Wistar rats were dosed with 0, 50, 100 or 150 mg Mancozeb/kg bw/day by gavage...... offspring. The dose of 150 mg/kg/day caused neurotoxicity in the pregnant dams, and was therefore reduced to 100 mg/kg bw/day in mid study. T4 levels showed a dose-dependent and significant decreased in dams from all three dose groups on GD 15, whereas offspring T4 levels, thyroid weights and histology were...

  20. Survey of Beaver-related Restoration Practices in Rangeland Streams of the Western USA

    Science.gov (United States)

    Pilliod, David S.; Rohde, Ashley T.; Charnley, Susan; Davee, Rachael R.; Dunham, Jason B.; Gosnell, Hannah; Grant, Gordon E.; Hausner, Mark B.; Huntington, Justin L.; Nash, Caroline

    2018-01-01

    Poor condition of many streams and concerns about future droughts in the arid and semi-arid western USA have motivated novel restoration strategies aimed at accelerating recovery and increasing water resources. Translocation of beavers into formerly occupied habitats, restoration activities encouraging beaver recolonization, and instream structures mimicking the effects of beaver dams are restoration alternatives that have recently gained popularity because of their potential socioeconomic and ecological benefits. However, beaver dams and dam-like structures also harbor a history of social conflict. Hence, we identified a need to assess the use of beaver-related restoration projects in western rangelands to increase awareness and accountability, and identify gaps in scientific knowledge. We inventoried 97 projects implemented by 32 organizations, most in the last 10 years. We found that beaver-related stream restoration projects undertaken mostly involved the relocation of nuisance beavers. The most common goal was to store water, either with beaver dams or artificial structures. Beavers were often moved without regard to genetics, disease, or potential conflicts with nearby landowners. Few projects included post-implementation monitoring or planned for longer term issues, such as what happens when beavers abandon a site or when beaver dams or structures breach. Human dimensions were rarely considered and water rights and other issues were mostly unresolved or addressed through ad-hoc agreements. We conclude that the practice and implementation of beaver-related restoration has outpaced research on its efficacy and best practices. Further scientific research is necessary, especially research that informs the establishment of clear guidelines for best practices.

  1. Survey of beaver-related restoration practices in rangeland streams of the western USA

    Science.gov (United States)

    Pilliod, David S.; Rohde, Ashley T.; Charnley, Susan; Davee, Rachael R; Dunham, Jason B.; Gosnell, Hannah; Grant, Gordon E.; Hausner, Mark B.; Huntington, Justin L.; Nash, Caroline

    2018-01-01

    Poor condition of many streams and concerns about future droughts in the arid and semi-arid western USA have motivated novel restoration strategies aimed at accelerating recovery and increasing water resources. Translocation of beavers into formerly occupied habitats, restoration activities encouraging beaver recolonization, and instream structures mimicking the effects of beaver dams are restoration alternatives that have recently gained popularity because of their potential socioeconomic and ecological benefits. However, beaver dams and dam-like structures also harbor a history of social conflict. Hence, we identified a need to assess the use of beaver-related restoration projects in western rangelands to increase awareness and accountability, and identify gaps in scientific knowledge. We inventoried 97 projects implemented by 32 organizations, most in the last 10 years. We found that beaver-related stream restoration projects undertaken mostly involved the relocation of nuisance beavers. The most common goal was to store water, either with beaver dams or artificial structures. Beavers were often moved without regard to genetics, disease, or potential conflicts with nearby landowners. Few projects included post-implementation monitoring or planned for longer term issues, such as what happens when beavers abandon a site or when beaver dams or structures breach. Human dimensions were rarely considered and water rights and other issues were mostly unresolved or addressed through ad-hoc agreements. We conclude that the practice and implementation of beaver-related restoration has outpaced research on its efficacy and best practices. Further scientific research is necessary, especially research that informs the establishment of clear guidelines for best practices.

  2. Beaver Activity, Holocene Climate and Riparian Landscape Change Across Stream Scales in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Levine, R.; Meyer, G. A.

    2013-12-01

    Beaver (Castor canadensis) have been part of the fluvial and riparian landscape across much of North America since the Pleistocene, increasing channel habitat complexity and expanding riparian landscapes. The fur trade, however, decimated beaver populations by the 1840s, and other human activities have limited beaver in many areas, including parts of the Greater Yellowstone Ecosystem (GYE). Understanding fluctuations in beaver occupation through the Holocene will aid in understanding the natural range of variability in beaver activity as well as climatic and anthropogenic impacts to fluvial systems. We are developing a detailed chronology of beaver-assisted sedimentation and overall fluvial activity for Odell and Red Rock Creeks (basin areas 83 and 99 km2) in Centennial Valley (CV), Montana, to augment related studies on the long-term effects of beaver on smaller GYE fluvial systems (basin areas 0.1-50 km2). In developing the CV chronology, we use the presence of concentrations of beaver-chewed sticks as a proxy for beaver occupancy. Beaver-stick deposits are found in paleochannel and fluvial terrace exposures. The relative ages of exposures were determined by elevation data from airborne LiDAR and ground surveys. Numerical ages were obtained from 36 14C ages (~30 more are pending) of beaver-stick wood collected during investigation of the stratigraphy. Most beaver-stick deposits are associated with ~ 1 meter of fine-grained sediment, interpreted as overbank deposits, commonly overlying gravelly sand or pebble gravel channel deposits which is consistent with enhanced overbank sedimentation associated with active beaver dams in CV streams. The CV deposits differ from those on smaller GYE streams where beaver-stick deposits are associated with abandoned dams (berms), infilled ponds and laminated sediments. The lack of pond-related deposition associated with CV beaver-stick deposits is consistent with frequent dam breaching (≤ 5 years) in the modern channel of Odell

  3. Maternal "junk-food" feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring.

    Science.gov (United States)

    Ong, Z Y; Muhlhausler, B S

    2011-07-01

    Individuals exposed to high-fat, high-sugar diets before birth have an increased risk of obesity in later life. Recent studies have shown that these offspring exhibit increased preference for fat, leading to suggestions that perinatal exposure to high-fat, high-sugar foods results in permanent changes within the central reward system that increase the subsequent drive to overconsume palatable foods. The present study has determined the effect of a maternal "junk-food" diet on the expression of key components of the mesolimbic reward pathway in the offspring of rat dams at 6 wk and 3 mo of age. We show that offspring of junk-food-fed (JF) dams exhibit higher fat intake from weaning until at least 3 mo of age (males: 16 ± 0.6 vs. 11 ± 0.8 g/kg/d; females: 19 ± 1.3 vs. 13 ± 0.4 g/kg/d; Pjunk-food intake in postnatal life.

  4. Impact of beaver ponds on river discharge and sediment deposition along the Chevral River, Ardennes, Belgium

    Science.gov (United States)

    Nyssen, Jan; Frankl, Amaury; Pontzeele, Jolien; De Visscher, Maarten; Billi, Paolo

    2013-04-01

    With the recovery of the European beaver (Castor fiber) and their capacity to engineer fluvial landscapes, questions arise as to how they influence river discharge and sediment transport. The Chevral river (Ardennes, Belgium) contains two beaver dam sequences which appeared in 2004 and count now about 30 dams. Flow discharges and sediment fluxes were measured at the in- and outflow of each dam sequence. Volumes of sediment deposited behind the dams were measured. Between 2004 and 2011, peak flows were topped off, and the magnitude of extreme events decreased. 1710 m³ of sediment were deposited behind the beaver dams, with an average sediment thickness of 25 cm. The thickness of the sediment layer is related to the area of the beaver ponds. Along the stream, beaver pond sediment thickness displayed a sinusoidal deposition pattern, in which ponds with thick sediment layers were preceded by a series of ponds with thinner sediment layers. A downstream textural coarsening in the dam sequences was also observed, probably due to dam failures subsequent to surges. Differences in sediment flux between the in- and outflow at the beaver pond sequence were related to the river hydrograph, with deposition taking place during the rising limbs and slight erosion during the falling limbs. The seven-year-old sequences have filtered 190 tons of sediment out of the Chevral river, which is of the same order of magnitude as the 374 tons measured in pond deposits, with the difference between the values corresponding to beaver excavations (60 tons), inflow from small tributaries, and runoff from the valley flanks. Hydrogeomorphic effects of C. fiber and C. canadensis activity are similar in magnitude. The detailed analysis of changes to hydrology in beaver pond sequences confirms the potential of beavers to contribute to river and wetland restoration and catchment management.

  5. Busy beavers gone wild

    Directory of Open Access Journals (Sweden)

    Grégory Lafitte

    2009-06-01

    Full Text Available We show some incompleteness results a la Chaitin using the busy beaver functions. Then, with the help of ordinal logics, we show how to obtain a theory in which the values of the busy beaver functions can be provably established and use this to reveal a structure on the provability of the values of these functions.

  6. High post-partum levels of corticosterone given to dams influence postnatal hippocampal cell proliferation and behavior of offspring: A model of post-partum stress and possible depression.

    Science.gov (United States)

    Brummelte, Susanne; Pawluski, Jodi L; Galea, Liisa A M

    2006-09-01

    Post-partum stress and depression (PPD) have a significant effect on child development and behavior. Depression is associated with hypercortisolism in humans, and the fluctuating levels of hormones, including corticosterone, during pregnancy and the post-partum, may contribute to PPD. The present study was developed to investigate the effects of high-level corticosterone (CORT) post-partum in the mother on postnatal neurogenesis and behavior in the offspring. Sprague-Dawley dams were treated with either CORT (40 mg/kg) or sesame oil injections daily for 26 days beginning the day after giving birth. Dams were tested in the forced swim test (FST) and in the open field test (OFT) on days 24-26 post-partum. Results showed that the dams exposed to CORT expressed "depressive-like" behavior compared to controls, with decreased struggling behavior and increased immobility in the FST. To investigate the effects of treatment on hippocampal postnatal cell proliferation and survival in the offspring, males and females from treated dams were injected with BrdU (50 mg/kg) on postnatal day 21 and perfused either 24 h (cell proliferation) or 21 days (cell survival) later. Furthermore, male and female offspring from each litter were tested in adulthood on various behavioral tests, including the forced swim test, open field test, resistance to capture test and elevated plus maze. Intriguingly, male, but not female, offspring of CORT-treated dams exhibited decreased postnatal cell proliferation in the dentate gyrus. Both male and female offspring of CORT-treated dams showed higher resistance to capture and greater locomotor activity as assessed in the open field test. As high levels of CORT may be a characteristic of stress and/or depression, these findings support a model of 'CORT-induced' post-partum stress and possibly depression and demonstrate that the offspring of affected dams can exhibit changes in postnatal neurogenesis and behavior in adulthood.

  7. Quantifying the multiple, environmental benefits of reintroducing the Eurasian Beaver

    Science.gov (United States)

    Brazier, Richard; Puttock, Alan; Graham, Hugh; Anderson, Karen; Cunliffe, Andrew; Elliott, Mark

    2016-04-01

    Beavers are ecological engineers with an ability to modify the structure and flow of fluvial systems and create complex wetland environments with dams, ponds and canals. Consequently, beaver activity has potential for river restoration, management and the provision of multiple environmental ecosystem services including biodiversity, flood risk mitigation, water quality and sustainable drinking water provision. With the current debate surrounding the reintroduction of beavers into the United Kingdom, it is critical to monitor the impact of beavers upon the environment. We have developed and implemented a monitoring strategy to quantify the impact of reintroducing the Eurasian Beaver on multiple environmental ecosystem services and river systems at a range of scales. First, the experimental design and preliminary results will be presented from the Mid-Devon Beaver Trial, where a family of beavers has been introduced to a 3 ha enclosure situated upon a first order tributary of the River Tamar. The site was instrumented to monitor the flow rate and quality of water entering and leaving the site. Additionally, the impacts of beavers upon riparian vegetation structure, water/carbon storage were investigated. Preliminary results indicate that beaver activity, particularly the building of ponds and dams, increases water storage within the landscape and moderates the river response to rainfall. Baseflow is enhanced during dry periods and storm flow is attenuated, potentially reducing the risk of flooding downstream. Initial analysis of water quality indicates that water entering the site (running off intensively managed grasslands upslope), has higher suspended sediment loads and nitrate levels, than that leaving the site, after moving through the series of beaver ponds. These results suggest beaver activity may also act as a means by which the negative impact of diffuse water pollution from agriculture can be mitigated thus providing cleaner water in rivers downstream

  8. A Model of Beaver Meadow Complex Evolution in the Silvies River Basin, Oregon.

    Science.gov (United States)

    Nash, C.; Grant, G.; Campbell, S. D.

    2014-12-01

    There is increasing evidence to suggest that the pervasive incision seen in the American West is due, in part, to the removal of beaver (Castor canadensis) in the first half of the 19th century. New restoration strategies for these systems focus on the reintroduction of beaver and construction of beaver dam analogs. Such dams locally raise streams beds and water tables, reconnect incised channels to their former floodplains, trap sediment, increase hydraulic diversity, and promote riparian vegetation. However, the geomorphic and hydrologic impacts of both the original beaver dams and their analogs are poorly understood. Observations in the Silvies River basin in Oregon, USA - an upland, semi-arid catchment with extremely high historic beaver populations and a presently recovering population, inform a conceptual model for valley floor evolution with beaver dams. The evolution of the beaver dam complex is characterized by eight stages of morphologic adjustment: water impoundment, sediment deposition, pond filling, multi-thread meadow creation, dam breaching, channel incision, channel widening, and floodplain development. Well-constructed beaver dams, given sufficient time and sediment flux, will evolve from a series of ponds to a multi-threaded channel flowing through a wet meadow complex. If a dam in the system fails, due to overtopping, undercutting, lack of maintenance, or abandonment, the upstream channel will concentrate into a single channel and incise, followed over time by widening once critical bank heights are exceeded. From stratigraphic, dendrochronologic, and geomorphic measurements, we are constraining average timescales associated with each stage's duration and transitional period. Measured sedimentation rates behind modern beaver dam analogs on five stream systems permit calculation of sediment flux over recent time periods, and aid in developing regional rates of sediment deposition over a range of drainage areas and gradients. Stratigraphic and

  9. A subsurface model of the beaver meadow complex

    Science.gov (United States)

    Nash, C.; Grant, G.; Flinchum, B. A.; Lancaster, J.; Holbrook, W. S.; Davis, L. G.; Lewis, S.

    2015-12-01

    Wet meadows are a vital component of arid and semi-arid environments. These valley spanning, seasonally inundated wetlands provide critical habitat and refugia for wildlife, and may potentially mediate catchment-scale hydrology in otherwise "water challenged" landscapes. In the last 150 years, these meadows have begun incising rapidly, causing the wetlands to drain and much of the ecological benefit to be lost. The mechanisms driving this incision are poorly understood, with proposed means ranging from cattle grazing to climate change, to the removal of beaver. There is considerable interest in identifying cost-effective strategies to restore the hydrologic and ecological conditions of these meadows at a meaningful scale, but effective process based restoration first requires a thorough understanding of the constructional history of these ubiquitous features. There is emerging evidence to suggest that the North American beaver may have had a considerable role in shaping this landscape through the building of dams. This "beaver meadow complex hypothesis" posits that as beaver dams filled with fine-grained sediments, they became large wet meadows on which new dams, and new complexes, were formed, thereby aggrading valley bottoms. A pioneering study done in Yellowstone indicated that 32-50% of the alluvial sediment was deposited in ponded environments. The observed aggradation rates were highly heterogeneous, suggesting spatial variability in the depositional process - all consistent with the beaver meadow complex hypothesis (Polvi and Wohl, 2012). To expand on this initial work, we have probed deeper into these meadow complexes using a combination of geophysical techniques, coring methods and numerical modeling to create a 3-dimensional representation of the subsurface environments. This imaging has given us a unique view into the patterns and processes responsible for the landforms, and may shed further light on the role of beaver in shaping these landscapes.

  10. Hypothalamic endoplasmic reticulum stress and insulin resistance in offspring of mice dams fed high-fat diet during pregnancy and lactation.

    Science.gov (United States)

    Melo, Arine M; Benatti, Rafaela O; Ignacio-Souza, Leticia M; Okino, Caroline; Torsoni, Adriana S; Milanski, Marciane; Velloso, Licio A; Torsoni, Marcio Alberto

    2014-05-01

    The goal of this study was to determine the presence early of markers of endoplasmic reticulum stress (ERS) and insulin resistance in the offspring from dams fed HFD (HFD-O) or standard chow diet (SC-O) during pregnancy and lactation. To address this question, we evaluated the hypothalamic and hepatic tissues in recently weaned mice (d28) and the hypothalamus of newborn mice (d0) from dams fed HFD or SC during pregnancy and lactation. Body weight, adipose tissue mass, and food intake were more accentuated in HFD-O mice than in SC-O mice. In addition, intolerance to glucose and insulin was higher in HFD-O mice than in SC-O mice. Compared with SC-O mice, levels of hypothalamic IL1-β mRNA, NFκB protein, and p-JNK were increased in HFD-O mice. Furthermore, compared with SC-O mice, hypothalamic AKT phosphorylation after insulin challenge was reduced, while markers of ERS (p-PERK, p-eIF2α, XBP1s, GRP78, and GRP94) and p-AMPK were increased in the hypothalamic tissue of HFD-O at d28 but not at d0. These damages to hypothalamic signaling were accompanied by increased triglyceride deposits, activation of NFκB, p-JNK, p-PERK and p-eIF2α. These point out lactation period as maternal trigger for metabolic changes in the offspring. These changes may occur early and quietly contribute to obesity and associated pathologies in adulthood. Although in rodents the establishment of ARC neuronal projections occurs during the lactation period, in humans it occurs during the third trimester. Gestational diabetes and obesity in this period may contribute to impairment of energy homeostasis. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Spatial and Temporal Variability of Channel Retention in a Lowland Temperate Forest Stream Settled by European Beaver (Castor fiber

    Directory of Open Access Journals (Sweden)

    Mateusz Grygoruk

    2014-09-01

    Full Text Available Beaver ponds remain a challenge for forest management in those countries where expansion of beaver (Castor fiber is observed. Despite undoubted economic losses generated in forests by beaver, their influence on hydrology of forest streams especially in terms of increasing channel retention (amount of water stored in the river channel, is considered a positive aspect of their activity. In our study, we compared water storage capacities of a lowland forest stream settled by beaver in order to unravel the possible temporal variability of beaver’s influence on channel retention. We compared distribution, total damming height, volumes and areas of beaver ponds in the valley of Krzemianka (Northeast Poland in the years 2006 (when a high construction activity of beaver was observed and in 2013 (when the activity of beaver decreased significantly. The study revealed a significant decrease of channel retention of beaver ponds from over 15,000 m3 in 2006 to 7000 m3 in 2013. The total damming height of the cascade of beaver ponds decreased from 6.6 to 5.6 m. Abandoned beaver ponds that transferred into wetlands, where lost channel retention was replaced by soil and groundwater retention, were more constant over time and less vulnerable to the external disturbance means of water storage than channel retention. We concluded that abandoned beaver ponds played an active role in increasing channel retention of the river analyzed for approximately 5 years. We also concluded that if the construction activity of beaver was used as a tool (ecosystem service in increasing channel retention of the river valley, the permanent presence of beaver in the riparian zone of forest streams should have been assured.

  12. Dam! Dam! Dam!

    International Nuclear Information System (INIS)

    McCully, P.

    1997-01-01

    The author of ''Silenced Rivers'' a book questioning the desirability of dam building and hydroelectric power generation argues the main themes of his book in this paper. Despite being hailed by politicians as good solutions to power generation problems, and enthusiastically pursued in China, the U.S.A., the former Soviet Union, India and Japan, dams have far-reaching ecological and human consequences. The ecosystems lost to flooding, and the agricultural land use lost, the human cost in terms of homes and employment lost to reservoirs, disease from water-borne infections such as malaria, and the hazards of dams overflowing or breaking are all factors which are against the case for dam construction. The author argues the hydroelectric power may be renewable, but the social, agricultural and ecological costs are too high to justify it as a method of first choice. (UK)

  13. Beaver herbivory on aquatic plants.

    Science.gov (United States)

    Parker, John D; Caudill, Christopher C; Hay, Mark E

    2007-04-01

    Herbivores have strong impacts on marine and terrestrial plant communities, but their impact is less well studied in benthic freshwater systems. For example, North American beavers (Castor canadensis) eat both woody and non-woody plants and focus almost exclusively on the latter in summer months, yet their impacts on non-woody plants are generally attributed to ecosystem engineering rather than herbivory. Here, we excluded beavers from areas of two beaver wetlands for over 2 years and demonstrated that beaver herbivory reduced aquatic plant biomass by 60%, plant litter by 75%, and dramatically shifted plant species composition. The perennial forb lizard's tail (Saururus cernuus) comprised less than 5% of plant biomass in areas open to beaver grazing but greater than 50% of plant biomass in beaver exclusions. This shift was likely due to direct herbivory, as beavers preferentially consumed lizard's tail over other plants in a field feeding assay. Beaver herbivory also reduced the abundance of the invasive aquatic plant Myriophyllum aquaticum by nearly 90%, consistent with recent evidence that native generalist herbivores provide biotic resistance against exotic plant invasions. Beaver herbivory also had indirect effects on plant interactions in this community. The palatable plant lizard's tail was 3 times more frequent and 10 times more abundant inside woolgrass (Scirpus cyperinus) tussocks than in spatially paired locations lacking tussocks. When the protective foliage of the woolgrass was removed without exclusion cages, beavers consumed nearly half of the lizard's tail leaves within 2 weeks. In contrast, leaf abundance increased by 73-93% in the treatments retaining woolgrass or protected by a cage. Thus, woolgrass tussocks were as effective as cages at excluding beaver foraging and provided lizard's tail plants an associational refuge from beaver herbivory. These results suggest that beaver herbivory has strong direct and indirect impacts on populations and

  14. The role of beaver in shaping steelhead trout (Oncorhynchus mykiss) habitat complexity and thermal refugia in a central Oregon stream

    Science.gov (United States)

    Consolati, F.; Wheaton, J. M.; Neilson, B. T.; Bouwes, N.; Pollock, M. M.

    2012-12-01

    The incised and degraded habitat of Bridge Creek, tributary to the John Day River in central Oregon, is thought to be limiting the local population of ESA-listed steelhead trout (Oncorhynchus mykiss). Restoration efforts for this watershed are aimed to improve their habitat through reconnecting the channel with portions of its former floodplain (now terraces) to increase stream habitat complexity and the extent of riparian vegetation. This is being done via the installation of over a hundred beaver dam support (BDS) structures that are designed to either mimic beaver dams or support existing beaver dams. The overall objective of this study is to determine if the BDS structures have had an effect on stream channel habitat complexity and thermal refugia in selected sections of Bridge Creek. Analysis of stream temperature data in restoration treatment and control areas will show the effects of beaver dams on stream temperature. Analysis of aerial imagery and high resolution topographic data will exhibit how the number and types of geomorphic units have changed after the construction of beaver dams. Combined, the results of this research are aimed to increase our understanding of how beaver dams impact fish habitat and stream temperature.

  15. Influence of Beaver-Induced Complexity on Storage of Organic Carbon and Sediment in Colorado Mountain Streams

    Science.gov (United States)

    Laurel, D.; Wohl, E.

    2016-12-01

    Beaver meadows (complexes of multiple different aged beaver dams and ponds) influence the storage of water, sediment, and nutrients. Although beaver meadows compose only a small fraction of catchment area, they provide a potentially large role in retaining these fluxes in mountain watersheds. Multiple dams and ponds in beaver meadows increase overbank flows leading to an anastomosing stream channel planform, and deposition of fine sediment along with particulate organic carbon. An earlier study estimated a range of cumulative carbon stored in 27 beaver meadows east of the continental divide in Rocky Mountain National Park. Storage ranged from 735,800 to 2.8 x 106 Mg carbon, with the high value estimating storage if all the meadows had active beaver (historic conditions pre-European settlement) and the lower value estimating current conditions where many of the meadows are abandoned. We combined geomorphic surveys, soil depth probing by rebar, and soil cores analyzed for carbon content to investigate the influence of beaver activity, meadow size, and meadow placement within the drainage on catchment-scale fluxes of fine sediment and organic carbon. We found carbon storage in floodplain soils to be highly variable across both active and abandoned meadows; however, active beaver meadows store more carbon on average than abandoned meadows. In addition, active meadows with high levels of beaver activity (multiple colonies) stored greater volumes of fine sediment behind dams and in ponds. These results have implications for the restoration potential of abandoned beaver meadows in mountain environments to store greater volumes of sediment and more organic carbon if beaver are successfully reintroduced.

  16. Coupled stream and population dynamics: Modeling the role beaver (Castor canadensis) play in generating juvenile steelhead (Oncorhynchus mykiss) habitat

    Science.gov (United States)

    Jordan, C.; Bouwes, N.; Wheaton, J. M.; Pollock, M.

    2013-12-01

    Over the past several centuries, the population of North American Beaver has been dramatically reduced through fur trapping. As a result, the geomorphic impacts long-term beaver occupancy and activity can have on fluvial systems have been lost, both from the landscape and from our collective memory such that physical and biological models of floodplain system function neither consider nor have the capacity to incorporate the role beaver can play in structuring the dynamics of streams. Concomitant with the decline in beaver populations was an increasing pressure on streams and floodplains through human activity, placing numerous species of stream rearing fishes in peril, most notably the ESA listing of trout and salmon populations across the entirety of the Western US. The rehabilitation of stream systems is seen as one of the primary means by which population and ecosystem recovery can be achieved, yet the methods of stream rehabilitation are applied almost exclusively with the expected outcome of a static idealized stream planform, occasionally with an acknowledgement of restoring processes rather than form and only rarely with the goal of a beaver dominated riverscape. We have constructed an individual based model of trout and beaver populations that allows the exploration of fish population dynamics as a function of stream habitat quality and quantity. We based the simulation tool on Bridge Creek (John Day River basin, Oregon) where we have implemented a large-scale restoration experiment using wooden posts to provide beavers with stable platforms for dam building and to simulate the dams themselves. Extensive monitoring captured geomorphic and riparian changes, as well as fish and beaver population responses; information we use to parameterize the model as to the geomorphic and fish response to dam building beavers. In the simulation environment, stream habitat quality and quantity can be manipulated directly through rehabilitation actions and indirectly

  17. Landsat time series analysis documents beaver migration into permafrost landscapes of arctic Alaska

    Science.gov (United States)

    Jones, B. M.; Tape, K. D.; Nitze, I.; Arp, C. D.; Grosse, G.; Zimmerman, C. E.

    2017-12-01

    Landscape-scale impacts of climate change in the Arctic include increases in growing season length, shrubby vegetation, winter river discharge, snowfall, summer and winter water temperatures, and decreases in river and lake ice thickness. Combined, these changes may have created conditions that are suitable for beaver colonization of low Arctic tundra regions. We developed a semi-automated workflow that analyzes Landsat imagery time series to determine the extent to which beavers may have colonized permafrost landscapes in arctic Alaska since 1999. We tested this approach on the Lower Noatak, Wulik, and Kivalina river watersheds in northwest Alaska and identified 83 locations representing potential beaver activity. Seventy locations indicated wetting trends and 13 indicated drying trends. Verification of each site using high-resolution satellite imagery showed that 80 % of the wetting locations represented beaver activity (damming and pond formation), 11 % were unrelated to beavers, and 9 % could not readily be distinguished as being beaver related or not. For the drying locations, 31 % represented beaver activity (pond drying due to dam abandonment), 62 % were unrelated to beavers, and 7 % were undetermined. Comparison of the beaver activity database with historic aerial photography from ca. 1950 and ca. 1980 indicates that beavers have recently colonized or recolonized riparian corridors in northwest Alaska. Remote sensing time series observations associated with the migration of beavers in permafrost landscapes in arctic Alaska include thermokarst lake expansion and drainage, thaw slump initiation, ice wedge degradation, thermokarst shore fen development, and possibly development of lake and river taliks. Additionally, beaver colonization in the Arctic may alter channel courses, thermal regimes, hyporheic flow, riparian vegetation, and winter ice regimes that could impact ecosystem structure and function in this region. In particular, the combination of beaver

  18. Beaver ponds' impact on fluvial processes (Beskid Niski Mts., SE Poland).

    Science.gov (United States)

    Giriat, Dorota; Gorczyca, Elżbieta; Sobucki, Mateusz

    2016-02-15

    Beaver (Castor sp.) can change the riverine environment through dam-building and other activities. The European beaver (Castor fiber) was extirpated in Poland by the nineteenth century, but populations are again present as a result of reintroductions that began in 1974. The goal of this paper is to assess the impact of beaver activity on montane fluvial system development by identifying and analysing changes in channel and valley morphology following expansion of beaver into a 7.5 km-long headwater reach of the upper Wisłoka River in southeast Poland. We document the distribution of beaver in the reach, the change in river profile, sedimentation type and storage in beaver ponds, and assess how beaver dams and ponds have altered channel and valley bottom morphology. The upper Wisłoka River fluvial system underwent a series of anthropogenic disturbances during the last few centuries. The rapid spread of C. fiber in the upper Wisłoka River valley was promoted by the valley's morphology, including a low-gradient channel and silty-sand deposits in the valley bottom. At the time of our survey (2011), beaver ponds occupied 17% of the length of the study reach channel. Two types of beaver dams were noted: in-channel dams and valley-wide dams. The primary effect of dams, investigated in an intensively studied 300-m long subreach (Radocyna Pond), was a change in the longitudinal profile from smooth to stepped, a local reduction of the water surface slope, and an increase in the variability of both the thalweg profile and surface water depths. We estimate the current rate of sedimentation in beaver ponds to be about 14 cm per year. A three-stage scheme of fluvial processes in the longitudinal and transverse profile of the river channel is proposed. C. fiber reintroduction may be considered as another important stage of the upper Wisłoka fluvial system development. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Role of the Small Intestine in Developmental Programming: Impact of Maternal Nutrition on the Dam and Offspring123

    Science.gov (United States)

    Meyer, Allison M; Caton, Joel S

    2016-01-01

    Small-intestinal growth and function are critical for optimal animal growth and health and play a major role in nutrient digestion and absorption, energy and nutrient expenditure, and immunological competence. During fetal and perinatal development, the small intestine is affected by the maternal environment and nutrient intake. In ruminants, altered small-intestinal mass, villi morphology, hypertrophy, hyperplasia, vascularity, and gene expression have been observed as a result of poor gestational nutrition or intrauterine growth restriction. Although many of these data come from fetal stages, data have also demonstrated that nutrition during mid- and late gestation affects lamb small-intestinal growth, vascularity, digestive enzyme activity, and gene expression at 20 and 180 d of age as well. The small intestine is known to be a highly plastic tissue, changing with nutrient intake and physiological state even in adulthood, and the maternal small intestine adapts to pregnancy and advancing gestation. In ruminants, the growth, vascularity, and gene expression of the maternal small intestine also adapt to the nutritional plane and specific nutrient intake such as high selenium during pregnancy. These changes likely alter both pre- and postnatal nutrient delivery to offspring. More research is necessary to better understand the role of the offspring and maternal small intestines in whole-animal responses to developmental programming, but programming of this plastic tissue seems to play a dynamic role in gestational nutrition impacts on the whole animal. PMID:27180380

  20. Protection of Levees against Beavers

    Science.gov (United States)

    Kozłowski, Wojciech; Balawejder, Adam

    2017-10-01

    Beavers are a protected species, so the levees must be properly protected so as not to harm the beavers and protect the levees from the destruction caused by these animals. This protection requires the use of bentonite mats as shaft seals, and wire mesh. Recently, such new protection structures began to be used successfully.

  1. The Buried Town of Beaver.

    Science.gov (United States)

    Jostad, Karen

    Local history as source material for environmental education is uniquely portrayed in this resource kit. Utilizing a Winona County Historical Society publication, "The Beaver Story" and accompanied by a teacher's guide, "The Buried Town of Beaver," and other teaching aids, a case study of the area can be developed. Based on the reminiscences of…

  2. The hydrological modeling in terms of determining the potential European beaver effect

    Science.gov (United States)

    Szostak, Marta; Jagodzińska, Jadwiga

    2017-06-01

    The objective of the paper was the hydrological analysis, in terms of categorizing main watercourses (based on coupled catchments) and marking areas covered by potential impact of the occurrence and activities of the European beaver Castor fiber. At the analysed area - the Forest District Głogów Małopolski there is a population of about 200 beavers in that Forest District. Damage inflicted by beavers was detected on 33.0 ha of the Forest District, while in the area of 13.9 ha the damage was small (below 10%). The monitoring of the beavers' behaviour and the analysis of their influence on hydrology of the area became an important element of using geoinformationtools in the management of forest areas. ArcHydro ArcGIS Esri module was applied, as an integrated set of tools for hydrographical analysis and modelling. Further steps of the procedure are hydrologic analyses such as: marking river networks on the DTM, filling holes, making maps of the flow direction, making the map of the accumulation flow, defining and segmentation of streams, marking elementary basins, marking coupled basins, making dams in the places, where beavers occur and localization of the area with a visible impact of damming. The result of the study includes maps prepared for the Forest District: the map of main rivers and their basins, categories of watercourses and compartments particularly threatened by beaver's foraging.

  3. Pulmonary exposure to carbon black by inhalation or instillation in pregnant mice: Effects on liver DNA strand breaks in dams and offspring

    DEFF Research Database (Denmark)

    Jackson, Petra; Hougaard, Karin Sørig; Boisen, Anne Mette Zenner

    2011-01-01

    cells and liver, and in offspring liver. Persistent lung inflammation was observed in exposed mothers. Inhalation exposure induced more DNA strand breaks in the liver of mothers and their offspring, whereas intratracheal instillation did not. Neither inhalation nor instillation affected gestation...... and lactation. Maternal inhalation exposure to Printex 90-induced liver DNA damage in the mothers and the in utero exposed offspring....

  4. Ecosystem engineering by invasive exotic beavers reduces in-stream diversity and enhances ecosystem function in Cape Horn, Chile.

    Science.gov (United States)

    Anderson, Christopher B; Rosemond, Amy D

    2007-11-01

    Species invasions are of global significance, but predicting their impacts can be difficult. Introduced ecosystem engineers, however, provide an opportunity to test the underlying mechanisms that may be common to all invasive engineers and link relationships between changes in diversity and ecosystem function, thereby providing explanatory power for observed ecological patterns. Here we test specific predictions for an invasive ecosystem engineer by quantifying the impacts of habitat and resource modifications caused by North American beavers (Castor canadensis) on aquatic macroinvertebrate community structure and stream ecosystem function in the Cape Horn Biosphere Reserve, Chile. We compared responses to beavers in three habitat types: (1) forested (unimpacted) stream reaches, (2) beaver ponds, and (3) sites immediately downstream of beaver dams in four streams. We found that beaver engineering in ponds created taxonomically simplified, but more productive, benthic macroinvertebrate assemblages. Specifically, macroinvertebrate richness, diversity and number of functional feeding groups were reduced by half, while abundance, biomass and secondary production increased three- to fivefold in beaver ponds compared to forested sites. Reaches downstream of beaver ponds were very similar to natural forested sections. Beaver invasion effects on both community and ecosystem parameters occurred predominantly via increased retention of fine particulate organic matter, which was associated with reduced macroinvertebrate richness and diversity (via homogenization of benthic microhabitat) and increased macroinvertebrate biomass and production (via greater food availability). Beaver modifications to macroinvertebrate community structure were largely confined to ponds, but increased benthic production in beaver-modified habitats adds to energy retention and flow for the entire stream ecosystem. Furthermore, the effects of beavers on taxa richness (negative) and measures of

  5. Signatures of self-assembly in size distributions of wood members in dam structures of Castor canadensis

    Directory of Open Access Journals (Sweden)

    David M. Blersch

    2014-12-01

    Full Text Available Beavers (Castor canadensis construct dams on rivers throughout most of their historical range in North America, and their impact on water patterns in the landscape is considerable. Dam formation by beavers involves two processes: (1 intentional construction through the selection and placement of wood and sediment, which facilitates (2 the passive capture and accretion of suspended wood and sediment. The second process is a self-assembly mechanism that the beavers leverage by utilizing energy subsidies of watershed transport processes. The relative proportion of beaver activity to self-assembly processes in dam construction, however, is unknown. Here we show that lotic self-assembly processes account for a substantial portion of the work expended in beaver dam construction. We found through comprehensive measurement of the stick dimensions that the distributions for diameter, length, and volume are log-normal. By noting evidence of teeth markings, we determined that size distributions skewed significantly larger for wood handled by beavers compared to those that were not. Subsequent mass calculations suggest that beavers perform 50%–70% of the work of wood member placement for dam assembly, with riparian self-assembly processes contributing the remainder. Additionally, our results establish a benchmark for assessing the proportion of self-assembly work in similar riparian structures. Keywords: Beaver dam, Construction, Castor canadensis, Self-assembly, Distribution, Wood

  6. Consuming a low-fat diet from weaning to adulthood reverses the programming of food preferences in male, but not in female, offspring of 'junk food'-fed rat dams.

    Science.gov (United States)

    Ong, Z Y; Muhlhausler, B S

    2014-01-01

    This study aimed to determine whether the negative effects of maternal 'junk food' feeding on food preferences and gene expression in the mesolimbic reward system could be reversed by weaning the offspring onto a low-fat diet. Offspring of control (n = 11) and junk food-fed (JF, n = 12) dams were weaned onto a standard rodent chow until 6 weeks (juvenile) or 3 months (adult). They were then given free access to both chow and junk food for 3 weeks and food preferences determined. mRNA expression of key components of the mesolimbic reward system was determined by qRT-PCR at 6 weeks, 3 and 6 months of age. In the juvenile group, both male and female JF offspring consumed more energy and carbohydrate during the junk food exposure at 6 weeks of age and had a higher body fat mass at 3 months (P junk food; however, female JF offspring had a higher body fat mass at 6 months (P junk food exposure on food preferences and fat mass can be reversed by consuming a low-fat diet from weaning to adulthood in males. Females, however, retain a higher propensity for diet-induced obesity even after consuming a low-fat diet for an extended period after weaning. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  7. Modeling intrinsic potential for beaver (Castor canadensis) habitat to inform restoration and climate change adaptation

    Science.gov (United States)

    Dittbrenner, Benjamin J.; Pollack, Michael M.; Schilling, Jason W.; Olden, Julian D.; Lawler, Joshua J.; Torgersen, Christian E.

    2018-01-01

    Through their dam-building activities and subsequent water storage, beaver have the potential to restore riparian ecosystems and offset some of the predicted effects of climate change by modulating streamflow. Thus, it is not surprising that reintroducing beaver to watersheds from which they have been extirpated is an often-used restoration and climate-adaptation strategy. Identifying sites for reintroduction, however, requires detailed information about habitat factors—information that is not often available at broad spatial scales. Here we explore the potential for beaver relocation throughout the Snohomish River Basin in Washington, USA with a model that identifies some of the basic building blocks of beaver habitat suitability and does so by relying solely on remotely sensed data. More specifically, we developed a generalized intrinsic potential model that draws on remotely sensed measures of stream gradient, stream width, and valley width to identify where beaver could become established if suitable vegetation were to be present. Thus, the model serves as a preliminary screening tool that can be applied over relatively large extents. We applied the model to 5,019 stream km and assessed the ability of the model to correctly predict beaver habitat by surveying for beavers in 352 stream reaches. To further assess the potential for relocation, we assessed land ownership, use, and land cover in the landscape surrounding stream reaches with varying levels of intrinsic potential. Model results showed that 33% of streams had moderate or high intrinsic potential for beaver habitat. We found that no site that was classified as having low intrinsic potential had any sign of beavers and that beaver were absent from nearly three quarters of potentially suitable sites, indicating that there are factors preventing the local population from occupying these areas. Of the riparian areas around streams with high intrinsic potential for beaver, 38% are on public lands and 17

  8. Modeling intrinsic potential for beaver (Castor canadensis) habitat to inform restoration and climate change adaptation.

    Science.gov (United States)

    Dittbrenner, Benjamin J; Pollock, Michael M; Schilling, Jason W; Olden, Julian D; Lawler, Joshua J; Torgersen, Christian E

    2018-01-01

    Through their dam-building activities and subsequent water storage, beaver have the potential to restore riparian ecosystems and offset some of the predicted effects of climate change by modulating streamflow. Thus, it is not surprising that reintroducing beaver to watersheds from which they have been extirpated is an often-used restoration and climate-adaptation strategy. Identifying sites for reintroduction, however, requires detailed information about habitat factors-information that is not often available at broad spatial scales. Here we explore the potential for beaver relocation throughout the Snohomish River Basin in Washington, USA with a model that identifies some of the basic building blocks of beaver habitat suitability and does so by relying solely on remotely sensed data. More specifically, we developed a generalized intrinsic potential model that draws on remotely sensed measures of stream gradient, stream width, and valley width to identify where beaver could become established if suitable vegetation were to be present. Thus, the model serves as a preliminary screening tool that can be applied over relatively large extents. We applied the model to 5,019 stream km and assessed the ability of the model to correctly predict beaver habitat by surveying for beavers in 352 stream reaches. To further assess the potential for relocation, we assessed land ownership, use, and land cover in the landscape surrounding stream reaches with varying levels of intrinsic potential. Model results showed that 33% of streams had moderate or high intrinsic potential for beaver habitat. We found that no site that was classified as having low intrinsic potential had any sign of beavers and that beaver were absent from nearly three quarters of potentially suitable sites, indicating that there are factors preventing the local population from occupying these areas. Of the riparian areas around streams with high intrinsic potential for beaver, 38% are on public lands and 17% are

  9. Impacts of beaver ponds on dissolved organic matter cycling in small temperate streams.

    Science.gov (United States)

    Larsen, J.; Lambert, T.; Larsen, A.; Lane, S.

    2017-12-01

    Beavers are engineers that modify the structure of river reaches and their hydrological functioning. By building dams, they modify the travel time of running waters and can lead to the flooding of surrounding soils and terrestrial vegetation, with potentially significant impact on biogeochemical cycles. Contradictory effects of beaver ponds on dissolved organic matter (DOM) concentration and composition have however been reported, and the underlying reasons are still unclear. In this study, we aimed to investigate the role of the landscape morphology as an important driver determining how a beaver population can affect stream DOM cycling. Four streams localized in Switzerland and Germany were visited during different seasons (spring, summer, winter) and monitored at upstream and downstream locations of beaver ponds across a hydrological cycle. The sites differed in terms of river channel morphology, presence or absence of floodplain, and vegetation cover. DOM composition was investigated through absorbance and fluorescence measurements coupled with parallel factor analysis (PARAFAC) along with stream water quality (nutrients, pH, dissolved oxygen and water temperature). The results show that the effects of beaver dams were variable, and emphasizes the importance of the geomorphological context.

  10. Toward an Understanding of Beaver Management as Human and Beaver Densities Increase

    OpenAIRE

    Siemer, William F.; Jonker, Sandra A.; Decker, Daniel J.; Organ, John F.

    2013-01-01

    Estimates of beaver (Castor canadensis) density play an important role in wildlife managers’ decisions about beaver population management, because managers anticipate higher incidence of problem complaints when a beaver population increases. To manage the impacts of beavers in an urbanizing landscape, managers need better information on changes in stakeholder beliefs and attitudes as beaver and human densities reach high levels. We conducted additional analysis of data collected in 2002 throu...

  11. Scrub-shrub bird habitat associations at multiple spatial scales in beaver meadows in Massachusetts

    Science.gov (United States)

    Chandler, R.B.; King, D.I.; DeStefano, S.

    2009-01-01

    Most scrub-shrub bird species are declining in the northeastern United States, and these declines are largely attributed to regional declines in habitat availability. American Beaver (Castor canadensis; hereafter “beaver”) populations have been increasing in the Northeast in recent decades, and beavers create scrub-shrub habitat through their dam-building and foraging activities. Few systematic studies have been conducted on the value of beaver-modified habitats for scrub-shrub birds, and these data are important for understanding habitat selection of scrub-shrub birds as well as for assessing regional habitat availability for these species. We conducted surveys in 37 beaver meadows in a 2,800-km2 study area in western Massachusetts during 2005 and 2006 to determine the extent to which these beaver-modified habitats are used by scrub-shrub birds, as well as the characteristics of beaver meadows most closely related to bird use. We modeled bird abundance in relation to microhabitat-, patch-, and landscape-context variables while adjusting for survey-specific covariates affecting detectability using N-mixture models. We found that scrub-shrub birds of regional conservation concern occupied these sites and that birds responded differently to microhabitat, patch, and landscape characteristics of beaver meadows. Generally, scrub-shrub birds increased in abundance along a gradient of increasing vegetation complexity, and three species were positively related to patch size. We conclude that these habitats can potentially play an important role in regional conservation of scrub-shrub birds and recommend that conservation priority be given to larger beaver meadows with diverse vegetation structure and composition.

  12. Immune activation in lactating dams alters sucklings' brain cytokines and produces non-overlapping behavioral deficits in adult female and male offspring: A novel neurodevelopmental model of sex-specific psychopathology.

    Science.gov (United States)

    Arad, Michal; Piontkewitz, Yael; Albelda, Noa; Shaashua, Lee; Weiner, Ina

    2017-07-01

    Early immune activation (IA) in rodents, prenatal through the mother or early postnatal directly to the neonate, is widely used to produce behavioral endophenotypes relevant to schizophrenia and depression. Given that maternal immune response plays a crucial role in the deleterious effects of prenatal IA, and lactation is a critical vehicle of immunological support to the neonate, we predicted that immune activation of the lactating dam will produce long-term abnormalities in the sucklings. Nursing dams were injected on postnatal day 4 with the viral mimic poly-I:C (4mg/kg) or saline. Cytokine assessment was performed in dams' plasma and milk 2h, and in the sucklings' hippocampus, 6h and 24h following poly-I:C injection. Male and female sucklings were assessed in adulthood for: a) performance on behavioral tasks measuring constructs considered relevant to schizophrenia (selective attention and executive control) and depression (despair and anhedonia); b) response to relevant pharmacological treatments; c) brain structural changes. Maternal poly-I:C injection caused cytokine alterations in the dams' plasma and milk, as well as in the sucklings' hippocampus. Lactational poly-I:C exposure led to sex-dimorphic (non-overlapping) behavioral abnormalities in the adult offspring, with male but not female offspring exhibiting attentional and executive function abnormalities (manifested in persistent latent inhibition and slow reversal) and hypodopaminergia, and female but not male offspring exhibiting despair and anhedonia (manifested in increased immobility in the forced swim test and reduced saccharine preference) and hyperdopaminergia, mimicking the known sex-bias in schizophrenia and depression. The behavioral double-dissociation predicted distinct pharmacological profiles, recapitulating the pharmacology of negative/cognitive symptoms and depression. In-vivo imaging revealed hippocampal and striatal volume reductions in both sexes, as found in both disorders. This is

  13. Beaver Ponds: Resurgent Nitrogen Sinks for Rural Watersheds in the Northeastern United States.

    Science.gov (United States)

    Lazar, Julia G; Addy, Kelly; Gold, Arthur J; Groffman, Peter M; McKinney, Richard A; Kellogg, Dorothy Q

    2015-09-01

    Beaver-created ponds and dams, on the rise in the northeastern United States, reshape headwater stream networks from extensive, free-flowing reaches to complexes of ponds, wetlands, and connecting streams. We examined seasonal and annual rates of nitrate transformations in three beaver ponds in Rhode Island under enriched nitrate-nitrogen (N) conditions through the use of N mass balance techniques on soil core mesocosm incubations. We recovered approximately 93% of the nitrate N from our mesocosm incubations. Of the added nitrate N, 22 to 39% was transformed during the course of the incubation. Denitrification had the highest rates of transformation (97-236 mg N m d), followed by assimilation into the organic soil N pool (41-93 mg N m d) and ammonium generation (11-14 mg N m d). Our denitrification rates exceeded those in several studies of freshwater ponds and wetlands; however, rates in those ecosystems may have been limited by low concentrations of nitrate. Assuming a density of 0.7 beaver ponds km of catchment area, we estimated that in nitrate-enriched watersheds, beaver pond denitrification can remove approximately 50 to 450 kg nitrate N km catchment area. In rural watersheds of southern New England with high N loading (i.e., 1000 kg km), denitrification from beaver ponds may remove 5 to 45% of watershed nitrate N loading. Beaver ponds represent a relatively new and substantial sink for watershed N if current beaver populations persist. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  14. The Effect of Beaver Activity on the Ammonium Uptake and Water Residence Time Characteristics of a Third-Order Stream Reach

    Science.gov (United States)

    Briggs, M.; Gooseff, M. N.; Wollheim, W. M.; Peterson, B. J.; Morkeski, K.

    2009-12-01

    Increasing beaver populations within low gradient basins in the northeastern United States are fundamentally changing the way water and dissolved nutrients are exported through these stream networks to the coast. Beaver dams can increase water residence time and contact with organic material, promote anoxic conditions and enhance both surface and hyporheic transient storage; all of these may have an impact on biogeochemical reactivity and nutrient retention. To quantitatively assess some of these effects we co-injected NaCl and NH4+ into the same 3rd-order stream reach in Massachusetts, USA under pre- and post-dam conditions. These experiments were done at similar discharge rates to isolate the impacts of a large natural beaver dam (7 m X 1.3 m) on the low-gradient (0.002) system where variable discharge also imparts a strong control on residence time. During the post-dam experiment there was an estimated 2300 m3 of water impounded behind the structure, which influenced more than 300 m of the 650 m stream reach. Our results showed that median transport time through the reach increased by 160% after dam construction. Additionally the tracer tailing time normalized to the corresponding median transport time increased from 1.08 to 1.51, indicating a pronounced tailing of the tracer signal in the post-dam condition. Data collected within the beaver pond just upstream of the dam indicated poor mixing and the presence of preferential flow paths through the generally stagnant zone. The uptake length (Sw) for NH4+ was 1250 m under the pre-dam condition, and may have changed for the post-dam reach in part because of the observed changes in residence time. As beaver population growth continues within these basins the consequences may be a smoothing of the outlet hydrograph and increased nutrient and organic matter removal and storage along the stream network.

  15. Plasma-Glucocorticoids and ACTH Levels During Different Periods of Activity in the European Beaver (Castor fiber L.).

    Science.gov (United States)

    Czerwińska, Joanna; Chojnowska, Katarzyna; Kamiński, Tadeusz; Bogacka, Iwona; Panasiewicz, Grzegorz; Smolińska, Nina; Kamińska, Barbara

    2015-01-01

    Glucocorticoids (GCs) and adrenocorticotropic hormone (ACTH) are major components of the classic endocrine stress response. Free-living vertebrates are characterized by circannual changes in the baseline and/or stress-induced secretion of GCs and ACTH. In mammalian species, GC and ACTH levels vary seasonally but there is no consensus to the season in which animals have elevated GC and ACTH levels. The aim of our study was to determine, for the first time, the type and amount of glucocorticoids produced in free-living beaver (Castor fiber L.)--the largest rodent in Eurasia, and to find out whether stress-induced plasma GC and ACTH levels show seasonal variations. Blood samples were obtained from animals under general anesthesia in April (pregnancy in females), July (offspring rearing) and November (preparing for the winter). The adrenals of beavers produce both cortisol and corticosterone, and plasma cortisol levels were higher than corticosterone. In the current experiment, plasma cortisol concentrations in beavers were affected by the season. The highest stress-associated cortisol levels were noted in males in July during offspring rearing. Corticosterone and ACTH concentrations in beavers remained generally constant, regardless of the season and sex. In conclusion, seasonal changes were observed only in relation to stress-induced plasma cortisol levels in the beaver.

  16. Using Seismic Refraction and Ground Penetrating Radar (GPR) to Characterize the Valley Fill in Beaver Meadows, Rocky Mountain National Park

    Science.gov (United States)

    Kramer, N.; Harry, D. L.; Wohl, E. E.

    2010-12-01

    This study is one of the first to use near surface geophysical techniques to characterize the subsurface stratigraphy in a high alpine, low gradient valley with a past glacial history and to obtain a preliminary grasp on the impact of Holocene beaver activity. Approximately 1 km of seismic refraction data and 5 km of GPR data were collected in Beaver Meadows, Rocky Mountain National Park. An asymmetric wedge of sediment ranging in depth from 0-20 m transverse to the valley profile was identified using seismic refraction. Complementary analysis of the GPR data suggests that the valley fill can be subdivided into till deposited during the Pleistocene glaciations and alluvium deposited during the Holocene. Two main facies were identified in the GPR profiles through pattern recognition. Facie Fd, which consists of chaotic discontinuous reflectors with an abundance of diffractions, is interpreted to be glacial till. Facie Fc, which is a combination of packages of complex slightly continuous reflectors interfingered with continuous horizontal to subhorizontal reflectors, is interpreted to be post-glacial alluvium and includes overbank, pond and in-channel deposits. Fc consistently overlies Fd throughout the study area and is no more than 7 m thick in the middle of the valley. The thickness of Holocene sedimentation (beaver dams, a high abundance of fine sediment including silts and clays, historical records of beavers, and the name "Beaver Meadows" all suggest that Holocene beaver activity played a large role in sediment accumulation at this site, despite the lack of surficial relict beaver dams containing wood.

  17. Resurgent beaver ponds in the northeastern United States: implications for greenhouse gas emissions.

    Science.gov (United States)

    Lazar, Julia G; Addy, Kelly; Welsh, Molly K; Gold, Arthur J; Groffman, Peter M

    2014-11-01

    Beaver ponds, a wetland type of increasing density in the northeastern United States, vary spatially and temporally, creating high uncertainty in their impact to greenhouse gas (GHG) emissions. We used floating static gas chambers to assess diffusive fluxes of methane (CH), carbon dioxide (CO), and nitrous oxide (NO) from the air-water interface of three beaver ponds (0.05-8 ha) in Rhode Island from fall 2012 to summer 2013. Gas flux was based on linear changes of gas concentrations in chambers over 1 h. Our results show that these beaver ponds generated considerable CH and CO emissions. Methane flux (18-556 mg m d) showed no significant seasonal differences, but the shallowest pond generated significantly higher CH flux than the other ponds. Carbon dioxide flux (0.5-22.0 g m d) was not significantly different between sites, but it was significantly higher in the fall, possibly due to the degradation of fresh leaves. Nitrous oxide flux was low (0-2.4 mg m d). Overall, CH and CO comprised most of the global warming potential, 61 and 38%, respectively. The shallowness of the beaver ponds may have limited the time needed for CH oxidation to CO before CH escaped to the atmosphere. Beaver dams also increase the aerial extent of hydric soils, which may transform riparian areas from upland GHG sinks to wetland GHG sources thereby changing the net global warming potential. Further studies tracking the pattern and conditions of beaver pond creation and abandonment will be essential to understanding their role as GHG sources. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  18. Using ecosystem engineers as tools in habitat restoration and rewilding: beaver and wetlands.

    Science.gov (United States)

    Law, Alan; Gaywood, Martin J; Jones, Kevin C; Ramsay, Paul; Willby, Nigel J

    2017-12-15

    Potential for habitat restoration is increasingly used as an argument for reintroducing ecosystem engineers. Beaver have well known effects on hydromorphology through dam construction, but their scope to restore wetland biodiversity in areas degraded by agriculture is largely inferred. Our study presents the first formal monitoring of a planned beaver-assisted restoration, focussing on changes in vegetation over 12years within an agriculturally-degraded fen following beaver release, based on repeated sampling of fixed plots. Effects are compared to ungrazed exclosures which allowed the wider influence of waterlogging to be separated from disturbance through tree felling and herbivory. After 12years of beaver presence mean plant species richness had increased on average by 46% per plot, whilst the cumulative number of species recorded increased on average by 148%. Heterogeneity, measured by dissimilarity of plot composition, increased on average by 71%. Plants associated with high moisture and light conditions increased significantly in coverage, whereas species indicative of high nitrogen decreased. Areas exposed to both grazing and waterlogging generally showed the most pronounced change in composition, with effects of grazing seemingly additive, but secondary, to those of waterlogging. Our study illustrates that a well-known ecosystem engineer, the beaver, can with time transform agricultural land into a comparatively species-rich and heterogeneous wetland environment, thus meeting common restoration objectives. This offers a passive but innovative solution to the problems of wetland habitat loss that complements the value of beavers for water or sediment storage and flow attenuation. The role of larger herbivores has been significantly overlooked in our understanding of freshwater ecosystem function; the use of such species may yet emerge as the missing ingredient in successful restoration. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights

  19. Radwaste challenge at Beaver Valley

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    Duquesne Light Company met the problem of accumulating low-level radioactive waste at its Beaver Valley nuclear plant with an aggressive program to reduce the quantity of contaminated material and demonstrate that the plant was improving its radiological protection. There was also an economic incentive to reduce low-level wastes. The imaginative campaign involved workers in the reduction effort through training and the adoption of practical approaches to reducing the amount of material exposed to radiation that include sorting trash by radiation level and a compacting system. 4 figures

  20. Beaver management in Norway : a model for continental Europe?

    OpenAIRE

    Parker, Howard; Rosell, Frank

    2003-01-01

    While Norway has been managing beaver (Castor fiber) for more than 150 years, most central European countries have little experience and none are presently harvesting beaver, despite rapidly growing populations and conflicts. Here we present the Norwegian beaver management model as an example. The main goals are to enhance biodiversity, produce a harvestable surplus, and reduce beaver-human conflicts. Beaver management should maximize recreational opportunities and allow landowners to profit ...

  1. Geophysical Investigation in Support of Beaver Dam Comprehensive Seepage Investigation.

    Science.gov (United States)

    1988-05-01

    29 JANUARY 1986 1118.35 3 MARCH 1986 1117.10 43 _9_ KANSAS CITY 65S city 630 FigreD.MiteNa rLA~c c roof To PMMEE OZRKS oll 4) 4 c0 x 9 c~ c 4) 154 iL...8217 q 10 S To F S T I U yI: 0 E H N IN sb a ITIU M C F T E A K E UOE S CRI P T 10N I N E T 0 s N s ~ LIYESTW *IE T I LIGHT To IAIRK i; RAYO I 31 1 ILl...VARlIER IV ISTE Figure 3. Geologic column 00 K 0 0 A~ V. 44 z u w LL0 s.- US LS C.) zo WECC; w0 0 Ř 4, + + +S + 4+ 03 4- + + z oO Z I 4- x 144 0

  2. Variability of Ecosystem State in Rivers Containing Natural Dams: A Chemical Analysis

    Science.gov (United States)

    Reynolds, Z. A.

    2015-12-01

    Flooding, and the resulting economic damage to roads and property, is associated with natural dams such as beaver dams or log jams. For this reason, humans often remove natural dams; however, river reaches with natural dams provide very different ecosystem services in comparison with free-flowing river reaches. Therefore, the goal of this project is to assess the differences in ecosystem state between these different river reach types in the northeastern United States. We focused on differences in basic chemistry (e.g., dissolved oxygen, pH, temperature, and organic carbon) to assess the impact of natural dams on river ecosystem state. Study sites include rivers in the White Mountains and southeastern New Hampshire at locations with beaver dams, beaver ponds, beaver meadows, log jams, and free-flowing reaches. Dissolved oxygen, ORP, pH, temperature, and conductivity were measured in the field with a YSI Professional Plus meter. Water samples were collected for subsequent laboratory analysis of total organic carbon with a Shimadzu TOC-L. Preliminary results show that the chemistry of river water varies with feature type. Most significantly, dissolved oxygen concentrations are highest in free-flowing reaches and lowest in beaver ponds. Although beaver ponds are often associated with lower pH, due the increased concentration of organic acids, some beaver ponds can increase pH when compared to free-flowing reaches on the same river. Early results also show that water chemistry returns quickly to the chemistry typical of the free-flowing river reaches after being altered by a natural dam. Overall, natural dams create a river system that has more heterogeneity, and therefore has opportunities to provide more ecosystem functions, than a purely free-flowing river; this can increase the number of supported instream and riparian species. By increasing the understanding of how natural dams affect the chemistry of river water, river engineers can improve their decisions on how

  3. [Assimilation of biological nitrogen by European beaver].

    Science.gov (United States)

    Vecherskiĭ, M V; Naumova, E I; Kostina, N V; Umarov, M M

    2009-01-01

    Nitrogenase activity, the abundance of diazotrophic bacteria, the structure and functional characteristics of the complex of microorganisms, and the content of nitrogen and carbon were determined in the contents of the gastrointestinal tract of the European beaver. A high nitrogen-fixing activity in the large intestine correlated with an increase in nitrogen content in the chyme upon its transfer over the gastrointestinal tract. It is assumed that microbial nitrogen fixation plays a major role in nitrogen nutrition of the European beaver.

  4. Differential regulation of hepatic transcription factors in the Wistar rat offspring born to dams fed folic acid, vitamin B12 deficient diets and supplemented with omega-3 fatty acids.

    Directory of Open Access Journals (Sweden)

    Akshaya Meher

    Full Text Available Nutritional status of the mother is known to influence various metabolic adaptations required for optimal fetal development. These may be mediated by transcription factors like peroxisome proliferator activated receptors (PPARs, which are activated by long chain polyunsaturated fatty acids. The objective of the current study was to examine the expression of different hepatic transcription factors and the levels of global methylation in the liver of the offspring born to dams fed micronutrient deficient (folic acid and vitamin B12 diets and supplemented with omega-3 fatty acids. Female rats were divided into five groups (n = 8/group as follows; control, folic acid deficient (FD, vitamin B12 deficient (BD and omega-3 fatty acid supplemented groups (FDO and BDO. Diets were given starting from pre-conception and continued throughout pregnancy and lactation. Pups were dissected at the end of lactation. Liver tissues were removed; snap frozen and stored at -80°C. Maternal micronutrients deficiency resulted in lower (p<0.05 levels of pup liver docosahexaenoic acid (DHA and arachidonic acid (ARA as compared to the control group. Pup liver PPARα and PPARγ expression was lower (p<0.05 in the BD group although there were no differences in the expression of SREBP-1c, LXRα and RXRα expression. Omega-3 fatty acids supplementation to this group normalized (p<0.05 levels of both PPARα and PPARγ but reduced (p<0.05 SREBP-1c, LXRα and RXRα expression. There was no change in any of the transcription factors in the pup liver in the FD group. Omega-3 fatty acids supplementation to this group reduced (p<0.05 PPARα, SREBP-1c and RXRα expression. Pup liver global methylation levels were higher (p<0.01 in both the micronutrients deficient groups and could be normalized (p<0.05 by omega-3 fatty acid supplementation. Our novel findings suggest a role for omega-3 fatty acids in the one carbon cycle in influencing the hepatic expression of transcription factors

  5. Mandibular incisor apicoectomy in a Canadian Beaver.

    Science.gov (United States)

    Steenkamp, Gerhard; Venter, Leon; Crossley, David; Buss, Peter

    2009-01-01

    A 52-month-old Canadian beaver was presented for treatment of lip trauma resulting from overgrowth of the right mandibular incisor tooth following earlier loss of the right maxillary incisor tooth. Extraction of the affected tooth was considered, but rejected due to the length of the embedded portion of rodent mandibular incisor teeth. The lip injury was managed by crown reduction (odontoplasty) of the overgrowing incisor tooth pending a more permanent treatment plan. A 2-cm apicoectomy of the right mandibular incisor tooth was performed to arrest growth of the tooth when the beaver was 82-months-old. The remainder of the tooth continued to erupt and was completely expelled during a 9-month period with one additional odontoplasty being required. The beaver continued to feed normally with just the left maxillary and mandibular incisor teeth until its death at 118-months, with odontoplasty performed twice on the remaining incisor teeth during the 30-months following exfoliation.

  6. Practical aspects of registration the transformation of a river valley by beavers using terrestrial laser scanning

    Science.gov (United States)

    Tyszkowski, Sebastian; Błaszkiewicz, Mirosław; Brykała, Dariusz; Gierszewski, Piotr; Kaczmarek, Halina; Kordowski, Jarosław; Słowiński, Michał

    2016-04-01

    Activity of beavers (Castor fiber) often significantly affects the environment in which they life. The most commonly observed effect of their being in environment is construction of beaver dams and formation a pond upstream. However, in case of a sudden break of a dam and beaver pond drainage, the valley below the dam may also undergo remodelling. The nature and magnitude of these changes depends on the quantity of water and its energy as well as on the geological structure of the valley. The effects of such events can be riverbank erosion, and the deposition of the displaced of erosion products in the form of sandbars or fans. The material can also be accumulated in local depressions or delivered to water bodies. Such events may occur multiple times in the same area. To assess their impact on the environment it is important to quantify the displaced material. The study of such transformations was performed within a small valley of the river of Struga Czechowska (Tuchola Pinewood Forest, Poland). The valley is mainly cut in sands and gravels. Its steep banks are overgrown with bushes and trees. The assessment of changes in morphology were based on the event of the beaver pond drainage of 2015. The study uses the measurements from the terrestrial laser scanning (scanner Riegl VZ-4000). The measurements were performed before and after the event. Each of the two models obtained for comparison was made up of more than 20 measurement stations. Point clouds were joined by Multi-Station Adjustment without placing in the terrain any objects of reference. During measurements attention was paid to the changes in morphology of both riverbed and valley surrounding. The paper presents the example of the recorded changes as well as the measurement procedure. Moreover, the aspects of fieldwork and issues related to post-processing, such as merging, filtering of point clouds and detection of changes, are also presented. This study is a contribution to the Virtual Institute of

  7. Competition favors elk over beaver in a riparian willow ecosystem

    Science.gov (United States)

    Baker, B.W.; Peinetti, H.R.; Coughenour, M.C.; Johnson, T.L.

    2012-01-01

    Beaver (Castor spp.) conservation requires an understanding of their complex interactions with competing herbivores. Simulation modeling offers a controlled environment to examine long-term dynamics in ecosystems driven by uncontrollable variables. We used a new version of the SAVANNA ecosystem model to investigate beaver (C. Canadensis) and elk (Cervus elapses) competition for willow (Salix spp.). We initialized the model with field data from Rocky Mountain National Park, Colorado, USA, to simulate a 4-ha riparian ecosystem containing beaver, elk, and willow. We found beaver persisted indefinitely when elk density was or = 30 elk km_2. The loss of tall willow preceded rapid beaver declines, thus willow condition may predict beaver population trajectory in natural environments. Beaver were able to persist with slightly higher elk densities if beaver alternated their use of foraging sites in a rest-rotation pattern rather than maintained continuous use. Thus, we found asymmetrical competition for willow strongly favored elk over beaver in a simulated montane ecosystem. Finally, we discuss application of the SAVANNA model and mechanisms of competition relative to beaver persistence as metapopulations, ecological resistance and alternative state models, and ecosystem regulation.

  8. Army Corps of Engineers: Actions Needed to Improve Cost Sharing for Dam Safety Repairs

    Science.gov (United States)

    2015-12-01

    agreements with the Corps, their history of being a sponsor, the financial impacts of cost sharing for dam safety repair projects, and the Corps...1240 (2007)) and Beaver Lake dam, AR (Pub. L. No. 102-377, 106 Stat. 1315, 1318 (1992), Pub. L. No. 102-580, § 209(f), 106 Stat. 4797, 4830 (1992...inaction in setting a clear policy for a provision under which sponsors face significant financial impacts has contributed to conditions under

  9. 75 FR 16728 - Beaver Creek Landscape Management Project, Ashland Ranger District, Custer National Forest...

    Science.gov (United States)

    2010-04-02

    ... DEPARTMENT OF AGRICULTURE Forest Service Beaver Creek Landscape Management Project, Ashland Ranger... manner that increases resiliency of the Beaver Creek Landscape Management Project area ecosystem to... requirements to require. The Beaver Creek Landscape Management Project includes treatments previously proposed...

  10. The impacts of Phalaris arundinacea (reed canary grass) invasion on wetland plant richness in the Oregon Coast Range, USA, depend on beavers

    Science.gov (United States)

    Perkins, T.; Wilson, M.

    2005-01-01

    Invasive plants can threaten diversity and ecosystem function. We examined the relationship between the invasive Phalaris arundinacea (reed canarygrass) and species richness in beaver wetlands in Oregon, USA. Four basins (drainages) were chosen and three sites each of beaver impoundments, unimpounded areas and areas upstream of debris jams were randomly chosen in each basin for further study (n = 36). Analysis of covariance (ANCOVA) showed that the relationship between Phalaris and species richness differed significantly (p = 0.01) by site type. Dam sites (beaver impoundments) exhibited a strong inverse relationship between Phalaris and species richness (bD = a??0.15), with one species lost for each 7% increase in Phalaris cover. In contrast, there was essentially no relationship between Phalaris cover and species richness in jam sites (debris jam impoundments formed by flooding; bJ = +0.01) and unimpounded sites (bU = a??0.03). The cycle of beaver impoundment and abandonment both disrupts the native community and provides an ideal environment for Phalaris, which once established tends to exclude development of herbaceous communities and limits species richness. Because beaver wetlands are a dominant wetland type in the Coast Range, Phalaris invasion presents a real threat to landscape heterogeneity and ecosystem function in the region.

  11. Proximate weather patterns and spring green-up phenology effect Eurasian beaver (Castor fiber) body mass and reproductive success: the implications of climate change and topography.

    Science.gov (United States)

    Campbell, Ruairidh D; Newman, Chris; Macdonald, David W; Rosell, Frank

    2013-04-01

    Low spring temperatures have been found to benefit mobile herbivores by reducing the rate of spring-flush, whereas high rainfall increases forage availability. Cold winters prove detrimental, by increasing herbivore thermoregulatory burdens. Here we examine the effects of temperature and rainfall variability on a temperate sedentary herbivore, the Eurasian beaver, Castor fiber, in terms of inter-annual variation in mean body weight and per territory offspring production. Data pertain to 198 individuals, over 11 years, using capture-mark-recapture. We use plant growth (tree cores) and fAPAR (a satellite-derived plant productivity index) to examine potential mechanisms through which weather conditions affect the availability and the seasonal phenology of beaver forage. Juvenile body weights were lighter after colder winters, whereas warmer spring temperatures were associated with lighter adult body weights, mediated by enhanced green-up phenology rates. Counter-intuitively, we observed a negative association between rainfall and body weight in juveniles and adults, and also with reproductive success. Alder, Alnus incana, (n = 68) growth rings (principal beaver food in the study area) exhibited a positive relationship with rainfall for trees growing at elevations >2 m above water level, but a negative relationship for trees growing beavers at the landscape scale via effects on spring green-up phenology and winter thermoregulation. Rainfall influences beavers at finer spatial scales through topographical interactions with plant growth, where trees near water level, prone to water logging, producing poorer forage in wetter years. Unlike most other herbivores, beavers are an obligate aquatic species that utilize a restricted 'central-place' foraging range, limiting their ability to take advantage of better forage growth further from water during wetter years. With respect to anthropogenic climate change, interactions between weather variables, plant phenology and

  12. The impact of small irrigation diversion dams on the recent migration rates of steelhead and redband trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Weigel, Dana E.; Connolly, Patrick J.; Powell, Madison S.

    2013-01-01

    Barriers to migration are numerous in stream environments and can occur from anthropogenic activities (such as dams and culverts) or natural processes (such as log jams or dams constructed by beaver (Castor canadensis)). Identification of barriers can be difficult when obstructions are temporary or incomplete providing passage periodically. We examine the effect of several small irrigation diversion dams on the recent migration rates of steelhead (Oncorhynchus mykiss) in three tributaries to the Methow River, Washington. The three basins had different recent migration patterns: Beaver Creek did not have any recent migration between sites, Libby Creek had two-way migration between sites and Gold Creek had downstream migration between sites. Sites with migration were significantly different from sites without migration in distance, number of obstructions, obstruction height to depth ratio and maximum stream gradient. When comparing the sites without migration in Beaver Creek to the sites with migration in Libby and Gold creeks, the number of obstructions was the only significant variable. Multinomial logistic regression identified obstruction height to depth ratio and maximum stream gradient as the best fitting model to predict the level of migration among sites. Small irrigation diversion dams were limiting population interactions in Beaver Creek and collectively blocking steelhead migration into the stream. Variables related to stream resistance (gradient, obstruction number and obstruction height to depth ratio) were better predictors of recent migration rates than distance, and can provide important insight into migration and population demographic processes in lotic species.

  13. Beaver Colony Density Trends on the Chequamegon-Nicolet National Forest, 1987 ? 2013

    OpenAIRE

    Ribic, Christine A.; Donner, Deahn M.; Beck, Albert J.; Rugg, David J.; Reinecke, Sue; Eklund, Dan

    2017-01-01

    The North American beaver (Castor canadensis) is a managed species in the United States. In northern Wisconsin, as part of the state-wide beaver management program, the Chequamegon-Nicolet National Forest removes beavers from targeted trout streams on U.S. Forest Service lands. However, the success of this management program has not been evaluated. Targeted removals comprise only 3% of the annual beaver harvest, a level of effort that may not affect the beaver population. We used colony locat...

  14. Restricted cross-scale habitat selection by American beavers.

    Science.gov (United States)

    Francis, Robert A; Taylor, Jimmy D; Dibble, Eric; Strickland, Bronson; Petro, Vanessa M; Easterwood, Christine; Wang, Guiming

    2017-12-01

    Animal habitat selection, among other ecological phenomena, is spatially scale dependent. Habitat selection by American beavers Castor canadensis (hereafter, beaver) has been studied at singular spatial scales, but to date no research addresses multi-scale selection. Our objectives were to determine if beaver habitat selection was specialized to semiaquatic habitats and if variables explaining habitat selection are consistent between landscape and fine spatial scales. We built maximum entropy (MaxEnt) models to relate landscape-scale presence-only data to landscape variables, and used generalized linear mixed models to evaluate fine spatial scale habitat selection using global positioning system (GPS) relocation data. Explanatory variables between the landscape and fine spatial scale were compared for consistency. Our findings suggested that beaver habitat selection at coarse (study area) and fine (within home range) scales was congruent, and was influenced by increasing amounts of woody wetland edge density and shrub edge density, and decreasing amounts of open water edge density. Habitat suitability at the landscape scale also increased with decreasing amounts of grass frequency. As territorial, central-place foragers, beavers likely trade-off open water edge density (i.e., smaller non-forested wetlands or lodges closer to banks) for defense and shorter distances to forage and obtain construction material. Woody plants along edges and expanses of open water for predator avoidance may limit beaver fitness and subsequently determine beaver habitat selection.

  15. The genetic legacy of multiple beaver reintroductions in Central Europe.

    Science.gov (United States)

    Frosch, Christiane; Kraus, Robert H S; Angst, Christof; Allgöwer, Rainer; Michaux, Johan; Teubner, Jana; Nowak, Carsten

    2014-01-01

    The comeback of the Eurasian beaver (Castor fiber) throughout western and central Europe is considered a major conservation success. Traditionally, several subspecies are recognised by morphology and mitochondrial haplotype, each linked to a relict population. During various reintroduction programs in the 20th century, beavers from multiple source localities were released and now form viable populations. These programs differed in their reintroduction strategies, i.e., using pure subspecies vs. mixed source populations. This inhomogeneity in management actions generated ongoing debates regarding the origin of present beaver populations and appropriate management plans for the future. By sequencing of the mitochondrial control region and microsatellite genotyping of 235 beaver individuals from five selected regions in Germany, Switzerland, Luxembourg, and Belgium we show that beavers from at least four source origins currently form admixed, genetically diverse populations that spread across the study region. While regional occurrences of invasive North American beavers (n = 20) were found, all but one C. fiber bore the mitochondrial haplotype of the autochthonous western Evolutionary Significant Unit (ESU). Considering this, as well as the viability of admixed populations and the fact that the fusion of different lineages is already progressing in all studied regions, we argue that admixture between different beaver source populations should be generally accepted.

  16. Dam Safety Concepts

    NARCIS (Netherlands)

    Duricic, J.

    2014-01-01

    The majority of dams constructed in the world are dams that can be categorized as embankment dams. Throughout history we can point to many failures of dams, and embankment dams in particular. Nowadays it is clear that the goal to construct stable dams has not been achieved, even with advanced

  17. Pulmonary adiaspiromycosis in the Eurasian beaver (Castor fiber) inhabiting Poland.

    Science.gov (United States)

    Dolka, I; Giżejewska, A; Giżejewski, Z; Kołodziejska-Lesisz, J; Kluciński, W

    2017-09-26

    Adiaspiromycosis is a rare fungal infection caused by saprophytic fungi Emmonsia spp. (type Ascomycota) occurring especially in small free-living mammals. The aim of this study was to evaluate the occurrence of histopathological lesions asscociated with adiaspiromycosis in the Eurasian beaver inhabiting Poland. In order to evaluate the presence of natural adiaspiromycosis we systematically investigated beaver populations from north-eastern Poland for adiaspores in the lungs. This study reveals for the first time the presence of pulmonary adiaspiromycosis of Eurasian beaver in Poland. As far as we know, there is no published data regarding pulmonary adiaspiromycosis in human patients in Poland.

  18. Maternal Rat Diabetes Mellitus Deleteriously Affects Insulin Sensitivity and Beta-Cell Function in the Offspring

    Directory of Open Access Journals (Sweden)

    Abdel-Baset M. Aref

    2013-01-01

    Full Text Available This study was designed to assess the effect of maternal diabetes in rats on serum glucose and insulin concentrations, insulin resistance, histological architecture of pancreas and glycogen content in liver of offspring. The pregnant rat females were allocated into two main groups: normal control group and streptozotocin-induced diabetic group. After birth, the surviving offspring were subjected to biochemical and histological examination immediately after delivery and at the end of the 1st and 2nd postnatal weeks. In comparison with the offspring of normal control dams, the fasting serum glucose level of offspring of diabetic mothers was significantly increased at the end of the 1st and 2nd postnatal weeks. Serum insulin level of offspring of diabetic dams was significantly higher at birth and decreased significantly during the following 2 postnatal weeks, while in normal rat offspring, it was significantly increased with progress of time. HOMA Insulin Resistance (HOMA-IR was significantly increased in the offspring of diabetic dams at birth and after 1 week than in normal rat offspring, while HOMA insulin sensitivity (HOMA-IS was significantly decreased. HOMA beta-cell function was significantly decreased at all-time intervals in offspring of diabetic dams. At birth, islets of Langerhans as well as beta cells in offspring of diabetic dams were hypertrophied. The cells constituting islets seemed to have a high division rate. However, beta-cells were degenerated during the following 2 post-natal weeks and smaller insulin secreting cells predominated. Vacuolation and necrosis of the islets of Langerhans were also observed throughout the experimental period. The carbohydrate content in liver of offspring of diabetic dams was at all-time intervals lower than that in control. The granule distribution was more random. Overall, the preexisting maternal diabetes leads to glucose intolerance, insulin resistance, and impaired insulin sensitivity and

  19. Algoflora of oxbow ponds transformed with beavers' activity

    OpenAIRE

    Макаревич, Т. А.; Белоус, В. В.; Гурчунова, Т. А.

    2016-01-01

    Algoflora of oxbow ponds transformed with beaver activity is characterized by high species richness and taxonomic diversity, high periphyton importance in the formation of algoflora compared with phytoplankton, prevalence of periphytic and benthic algae over typically planktonic forms

  20. Reconstruction of the MSRs in-situ at Beaver Valley

    International Nuclear Information System (INIS)

    Yarden, A.; Tam, C.W.; Deahna, S.T.; McFeaters, C.V.

    1992-01-01

    The Moisture Separator Reheaters (MSRs) have been problem components at Beaver Valley 1 pressurized water reactor since the plant started up 16 years ago, many of the problems encountered being widespread in the nuclear industry. In 1991, Duquesne Light rebuilt the Beaver Valley 1 MSRs and in 1992 did the same at unit 2. The reconstruction projects have proved cost effective with short payback times and significant improvements in station performance. (Author)

  1. Offspring Protection

    Directory of Open Access Journals (Sweden)

    Eric T. Steiner

    2016-08-01

    Full Text Available Parental aggression, that is, offspring protection aggression, can be viewed as a type of parental investment. Most mammalian males do not exhibit parental investment and therefore exhibit little, if any, parental aggression. Men demonstrate parental investment, and are typically more physically aggressive than women, but parental physical aggression in humans has been largely unexplored. The current study examined potential sex differences in estimates of parental physical aggression involving hypothetical situations, while controlling for general physical aggression. A self-report measure was administered to 217 students from a western U.S. university (55 male nonparents, 50 female nonparents, 54 fathers, and 58 mothers. Male nonparents reported higher parental physical aggression than female nonparents, but there was no difference between mothers and fathers. The results are interpreted in light of ancestral effects of sexual selection and proximal effects of sex differences in testosterone, risk taking, and fear aversion.

  2. Evaluation of Glycemic and Lipid Profile of Offspring of Diabetic Wistar Rats Treated with Malpighia emarginata Juice

    Directory of Open Access Journals (Sweden)

    Sandra M. Barbalho

    2011-01-01

    Full Text Available Knowing that maternal diabetes is related to hyperglycemia and fetal hyperinsulinemia, which affect the lipid metabolism, the aim of this study was to evaluate the effects of Malpighia emarginata (acerola juice on the glycemic and lipid profile of offspring of diabetic and nondiabetic Wistar rats. The adult offspring of non-diabetic dams and of dams with severe streptozotocin-induced diabetes were divided into groups: G1, offspring (of control dams treated with water, G2, offspring (of diabetic dams treated with water, G3, male offspring (of control dams treated with acerola juice, and G4, male offspring (of diabetic dams treated with acerola juice. The offspring of diabetic dams treated with acerola juice showed significantly decreased levels of glucose, cholesterol, triglycerides, and increased HDL-c. The use of acerola juice is a potential strategy to aid in the prevention of DM and dyslipidemia and its complications or to act as an auxiliary in the treatment of these diseases.

  3. NRC inventory of dams

    International Nuclear Information System (INIS)

    Lear, G.E.; Thompson, O.O.

    1983-01-01

    The NRC Inventory of Dams has been prepared as required by the charter of the NRC Dam Safety Officer. The inventory lists 51 dams associated with nuclear power plant sites and 14 uranium mill tailings dams (licensed by NRC) in the US as of February 1, 1982. Of the 85 listed nuclear power plants (148 units), 26 plants obtain cooling water from impoundments formed by dams. The 51 dams associated with the plants are: located on a plant site (29 dams at 15 plant sites); located off site but provide plant cooling water (18 dams at 11 additional plant sites); and located upstream from a plant (4 dams) - they have been identified as dams whose failure, and ensuing plant flooding, could result in a radiological risk to the public health and safety. The dams that might be considered NRC's responsibility in terms of the federal dam safety program are identified. This group of dams (20 on nuclear power plant sites and 14 uranium mill tailings dams) was obtained by eliminating dams that do not pose a flooding hazard (e.g., submerged dams) and dams that are regulated by another federal agency. The report includes the principal design features of all dams and related useful information

  4. 76 FR 13344 - Beaver Creek Landscape Management Project, Ashland Ranger District, Custer National Forest...

    Science.gov (United States)

    2011-03-11

    ... DEPARTMENT OF AGRICULTURE Forest Service Beaver Creek Landscape Management Project, Ashland Ranger... Impact Statement for the Beaver Creek Landscape Management Project was published in the Federal Register... Responsible Official for the Beaver Creek Landscape Management Project. DATES: The Final Environmental Impact...

  5. 77 FR 62147 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Pittsburgh-Beaver...

    Science.gov (United States)

    2012-10-12

    ... Promulgation of Air Quality Implementation Plans; Pennsylvania; Pittsburgh-Beaver Valley Nonattainment Area... (EPA). ACTION: Final rule. SUMMARY: EPA is making two determinations regarding the Pittsburgh- Beaver... 12.7 Collocated Armstrong 42-005-0001 Kittaning......... 11.0 13.2 12.1 12.1 Incomplete \\2\\ Beaver 42...

  6. 77 FR 34297 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Pittsburgh-Beaver...

    Science.gov (United States)

    2012-06-11

    ... Promulgation of Air Quality Implementation Plans; Pennsylvania; Pittsburgh-Beaver Valley Nonattainment Area... Pittsburgh-Beaver Valley fine particulate matter (PM 2.5 ) nonattainment area (hereafter referred to as ``the... designations process. The Pittsburgh Area is comprised of the counties of Beaver, Butler, Washington, and...

  7. 78 FR 28780 - Proposed Flood Elevation Determinations for Beaver County, Pennsylvania (All Jurisdictions)

    Science.gov (United States)

    2013-05-16

    ...-2013-0002; Internal Agency Docket No. FEMA-B-1147] Proposed Flood Elevation Determinations for Beaver... proposed rule concerning proposed flood elevation determinations for Beaver County, Pennsylvania (All... Beaver County, Pennsylvania. Because FEMA has or will be issuing a Revised Preliminary Flood Insurance...

  8. Habitat and conservation status of the beaver in the Sierra San Luis Sonora, Mexico

    Science.gov (United States)

    Karla Pelz Serrano; Eduardo Ponce Guevara; Carlos A. Lopez Gonzalez

    2005-01-01

    The status of beaver (Castor canadensis) in northeastern Sonora, Mexico, is uncertain. We surveyed the Cajon Bonito River to assess the beaver’s status and habitat and found five colonies. Limiting factors appear to be pollution due to animal waste, deforestation of riparian trees, and human exploitation. Beavers did not appear to require habitat...

  9. A Review of Techniques for Minimizing Beaver and White-Tailed Deer Damage in Southern Hardwoods

    Science.gov (United States)

    Edward P. Hill; Douglas N. Lasher; R. Blake. Roper

    1978-01-01

    Methods of reducing beaver and deer damage to hardwood forest resources are reviewed. Beaver controls considered were poisons, chemosterilants, predators, and trapping. Population reduction through trapping with 330 conibear traps for two weeks during two successive years effectively eliminates beaver from small watersheds and shows greater promise for control than...

  10. Dam's infection progress and within-herd prevalence as predictors of Mycobacterium avium subsp. paratuberculosis ELISA response in Danish Holstein cattle

    DEFF Research Database (Denmark)

    Nielsen, Søren Saxmose; Hansen, Kira Frello; Kvist, Louise

    2016-01-01

    potentially important for MAP transmission control. The objective of this study was therefore to assess the dam's infection progress and the within-herd test-prevalence as predictors of MAP infection in Danish dairy cattle. MAP specific antibody ELISA records from 95,025 dam-offspring pairs were combined...... with test-prevalence estimates from 939 Danish Holstein herds. The odds of testing ELISA-positive given the within-herd test-prevalence and the time-period a dam had had MAP specific antibodies were estimated for the offspring. Both dams and offspring were tested as adults, and parity-group was used...

  11. Yersinia pseudotuberculosis septicemia in a beaver from Washington State.

    Science.gov (United States)

    Gaydos, Joseph K; Zabek, Erin; Raverty, Stephen

    2009-10-01

    An emaciated, free-ranging, sub-adult, male beaver (Castor canadensis) was found dead and was necropsied. Microscopically, the beaver had acute necrotizing hepatitis and splenitis with florid lobulated colonies of extracellular coccobacilli. Intravascular septic emboli were identified in lung, small intestine, and kidney, and discrete ulcers with scattered superficial extracellular accumulation of coccobacilli were noted on tail margins and plantar surfaces of the hind feet. Yersinia pseudotuberculosis was cultured on Columbia blood and MacConkey agar and identified by API 20E. Based on the pathology and acute mortality described in this case, as well as historical reports of Y. pseudotuberculosis related mortality in other beavers, this species could serve as a public health sentinel for localized occurrences of this bacterium.

  12. Programming Body Composition in Offspring by Maternal Obesity Is Associated with Increased Adipogenesis and Decreased WNT/ Beta-Catenin Signaling in the Adipose Tissue

    Science.gov (United States)

    Maternal obesity during pregnancy significantly influences the risk of obesity in the offspring. We recently demonstrated that maternal obesity at conception programs obesity in the offspring. Obese dam offspring when weaned on high-fat diets gain significantly greater body weight/adiposity (via NMR...

  13. Age-related changes in somatic condition and reproduction in the Eurasian beaver: Resource history influences onset of reproductive senescence.

    Directory of Open Access Journals (Sweden)

    Ruairidh D Campbell

    Full Text Available Using 15 years of data from a stable population of wild Eurasian beavers (Castor fiber, we examine how annual and lifetime access to food resources affect individual age-related changes in reproduction and somatic condition. We found an age-related decline in annual maternal reproductive output, after a peak at age 5-6. Rainfall, an established negative proxy of annual resource availability for beavers, was consistently associated with lower reproductive output for females of all ages. In contrast, breeding territory quality, as a measure of local resource history over reproductive lifetimes, caused differences in individual patterns of reproductive senescence; animals from lower quality territories senesced when younger. Litter size was unrelated to maternal age, although adult body weight increased with age. In terms of resource effects, in poorer years but not in better years, older mothers produced larger offspring than did younger mothers, giving support to the constraint theory. Overall, our findings exemplify state-dependent life-history strategies, supporting an effect of resources on reproductive senescence, where cumulative differences in resource access, and not just reproductive strategy, mediate long-term reproductive trade-offs, consistent with the disposable soma and reproductive restraint theories. We propose that flexible life-history schedules could play a role in the dynamics of populations exhibiting reproductive skew, with earlier breeding opportunities leading to an earlier senescence schedule through resource dependent mechanisms.

  14. High dietary fat intake during lactation promotes development of diet-induced obesity in male offspring of mice.

    Science.gov (United States)

    Tsuduki, Tsuyoshi; Kitano, Yasuna; Honma, Taro; Kijima, Ryo; Ikeda, Ikuo

    2013-01-01

    The maternal nutritional status during pregnancy and lactation influences the risk of obesity in offspring, but the details of this phenomenon are unclear. In particular, there is little information on the influence on the offspring of the maternal nutritional status during lactation only. Therefore, in this study, we examined the influence of high dietary fat intake in dams during lactation on the risk of obesity in offspring, using C57BL/6J mice. The mice were fed a control diet (CD) during pregnancy. After birth, dams were fed a CD or a high-fat diet (HD) during lactation (3 wk). Fat and energy were significantly increased in milk from dams fed a HD during lactation. Male offspring were weaned at 3 wk old and fed a CD for 4 wk, which resulted in no significant difference in their physique. Four weeks after weaning, the offspring (7 wk old) were fed a CD or HD for 4 wk to induce obesity. High dietary fat intake in dams and offspring promoted lipid accumulation in white adipose tissue and adipocyte hypertrophy in male offspring. The underlying mechanism may involve an increase in expression of Lpl and a decrease in expression of Hsl in white adipose tissue of offspring. In conclusion, our results show that high dietary fat intake during lactation promotes development of diet-induced obesity in male offspring.

  15. Maternal chocolate and sucrose soft drink intake induces hepatic steatosis in rat offspring associated with altered lipid gene expression profile

    DEFF Research Database (Denmark)

    Kjærgaard, Maj; Nilsson, C.; Rosendal, A.

    2014-01-01

    weight gain and adiposity in offspring born to chow-fed dams. Conclusion: Our results suggest that supplementation of chocolate and soft drink during gestation and lactation contributes to early onset of hepatic steatosis associated with changes in hepatic gene expression and lipid handling....... until weaning, giving four dietary groups. Results: At postnatal day 1, offspring from high-fat/high-sucrose-fed dams were heavier and had increased hepatic triglycerides (TG), hepatic glycogen, blood glucose and plasma insulin compared with offspring from chow-fed dams. Hepatic genes involved in lipid...... oxidation, VLDL transport and insulin receptor were down-regulated, whereas FGF21 expression was up-regulated. Independent of postnatal litter size, offspring from high-fat/high-sucrose-fed dams aged 21 days had still increased hepatic TG and up-regulated FGF21 expression, while plasma insulin started...

  16. Alpine dams

    Directory of Open Access Journals (Sweden)

    Alain Marnezy

    2009-03-01

    Full Text Available Les barrages-réservoirs de montagne ont été réalisés initialement dans les Alpes pour répondre à la demande d’énergie en période hivernale. Une certaine diversification des usages de l’eau s’est ensuite progressivement développée, en relation avec le développement touristique des collectivités locales. Aujourd’hui, la participation des ouvrages d’Électricité De France à la production de neige de culture représente une nouvelle étape. Dans les régions où les aménagements hydroélectriques sont nombreux, les besoins en eau pour la production de neige peuvent être résolus par prélèvements à partir des adductions EDF. Les gestionnaires de stations échappent ainsi aux inconvénients liés à la construction et à la gestion des « retenues collinaires ». Cette évolution, qui concerne déjà quelques régions alpines comme la haute Maurienne ou le Beaufortin, apparaît comme une forme renouvelée d’intégration territoriale de la ressource en eau.Mountain reservoirs were initially built in the Alps to meet energy needs in the winter. A certain diversification in the uses of water then gradually developed, related to tourism development in the local communities. Today, the use of facilities belonging to EDF (French Electricity Authority to provide water for winter resorts to make artificial snow represents a new phase. By taking water from EDF resources to supply snow-making equipment, resort managers are thus able to avoid the problems related to the construction and management of small headwater dams. This new orientation in the use of mountain water resources already affects a number of alpine regions such as the Upper Maurienne valley and Beaufortain massif and represents a renewed form of the territorial integration of water resources.

  17. Prenatal polycyclic aromatic hydrocarbon, adiposity, peroxisome proliferator-activated receptor (PPAR γ methylation in offspring, grand-offspring mice.

    Directory of Open Access Journals (Sweden)

    Zhonghai Yan

    Full Text Available Greater levels of prenatal exposure to polycyclic aromatic hydrocarbon (PAH have been associated with childhood obesity in epidemiological studies. However, the underlying mechanisms are unclear.We hypothesized that prenatal PAH over-exposure during gestation would lead to weight gain and increased fat mass in offspring and grand-offspring mice. Further, we hypothesized that altered adipose gene expression and DNA methylation in genes important to adipocyte differentiation would be affected.Pregnant dams were exposed to a nebulized PAH mixture versus negative control aerosol 5 days a week, for 3 weeks. Body weight was recorded from postnatal day (PND 21 through PND60. Body composition, adipose cell size, gene expression of peroxisome proliferator-activated receptor (PPAR γ, CCAAT/enhancer-binding proteins (C/EBP α, cyclooxygenase (Cox-2, fatty acid synthase (FAS and adiponectin, and DNA methylation of PPAR γ, were assayed in both the offspring and grand-offspring adipose tissue.Offspring of dams exposed to greater PAH during gestation had increased weight, fat mass, as well as higher gene expression of PPAR γ, C/EBP α, Cox2, FAS and adiponectin and lower DNA methylation of PPAR γ. Similar differences in phenotype and DNA methylation extended through the grand-offspring mice.Greater prenatal PAH exposure was associated with increased weight, fat mass, adipose gene expression and epigenetic changes in progeny.

  18. Agreement Between Community College of Beaver County and Community College of Beaver County Society of the Faculty (PSEA/NEA). September 1, 1972 to August 31, 1974.

    Science.gov (United States)

    Beaver County Community Coll., Monaca, PA.

    This document contains the agreement between the Community College of Beaver County and the Community College of Beaver County Society of the Faculty for the period from September 1, 1972 through August 31, 1974. Contained in the articles of the agreement are sections covering academic freedom, grievance procedures, rights of faculty, use of…

  19. Construction of anhydrite dams

    Energy Technology Data Exchange (ETDEWEB)

    Bortoluzzi, L; Francois, G

    1977-05-01

    To construct a ventilation dam, the road is closed with a fibreglass sheet onto which 3 or 4 cm of anhydrite paste is sprayed. The equipment necessary is described, and the cost is compared with that of an aggregate dam.

  20. Dam removal: Listening in

    Science.gov (United States)

    Foley, M. M.; Bellmore, J. R.; O'Connor, J. E.; Duda, J. J.; East, A. E.; Grant, G. E.; Anderson, C. W.; Bountry, J. A.; Collins, M. J.; Connolly, P. J.; Craig, L. S.; Evans, J. E.; Greene, S. L.; Magilligan, F. J.; Magirl, C. S.; Major, J. J.; Pess, G. R.; Randle, T. J.; Shafroth, P. B.; Torgersen, C. E.; Tullos, D.; Wilcox, A. C.

    2017-07-01

    Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal tends to quickly reestablish connectivity, restoring the movement of material and organisms between upstream and downstream river reaches; (4) geographic context, river history, and land use significantly influence river restoration trajectories and recovery potential because they control broader physical and ecological processes and conditions; and (5) quantitative modeling capability is improving, particularly for physical and broad-scale ecological effects, and gives managers information needed to understand and predict long-term effects of dam removal on riverine ecosystems. Although these studies collectively enhance our understanding of how riverine ecosystems respond to dam removal, knowledge gaps remain because most studies have been short (< 5 years) and do not adequately represent the diversity of dam types, watershed conditions, and dam-removal methods in the U.S.

  1. Fire effects on the Point Reyes Mountain Beaver at Point Reyes National Seashore, California

    Science.gov (United States)

    Fellers, Gary M.; Pratt, David; Griffin, Jennifer L.

    2004-01-01

    In October 1995, a wildlands fire burned 5,000 ha on the Point Reyes peninsula, California, USA. In most of the nonforested areas, the fire effectively cleared the ground of litter and vegetation and revealed thousands of Point Reyes mountain beaver (Aplodontia rufa phaea) burrow openings. In the first 6 months after the fire, we surveyed burned coastal scrub and riparian habitat to (1) count the number of burrow openings that existed at the time of the fire, and (2) evaluate whether signs of post-fire mountain beaver activity were evident. We estimated that only 0.4–1.7% of mountain beavers within the burn area survived the fire and immediate post-fire period. We monitored mountain beaver activity for 5 years at 8 sites where mountain beavers survived, and found little or no recovery. We estimate that the mountain beaver population will take 15–20 years post-fire to recover.

  2. Dams designed to fail

    Energy Technology Data Exchange (ETDEWEB)

    Penman, A. [Geotechnical Engineering Consultants, Harpenden (United Kingdom)

    2004-09-01

    New developments in geotechnical engineering have led to methods for designing and constructing safe embankment dams. Failed dams can be categorized as those designed to fail, and those that have failed unexpectedly. This presentation outlined 3 dam failures: the 61 m high Malpasset Dam in France in 1959 which killed 421; the 71 m high Baldwin Hills Dam in the United States in 1963 which killed 5; and, the Vajont Dam in Italy in 1963 which killed 2,600 people. Following these incidents, the International Commission for Large Dams (ICOLD) reviewed regulations on reservoir safety. The 3 dams were found to have inadequate spillways and their failures were due to faults in their design. Fuse plug spillways, which address this problem, are designed to fail if an existing spillway proves inadequate. They allow additional discharge to prevent overtopping of the embankment dam. This solution can only be used if there is an adjacent valley to take the additional discharge. Examples of fuse gates were presented along with their effect on dam safety. A research program is currently underway in Norway in which high embankment dams are being studied for overtopping failure and failure due to internal erosion. Internal erosion has been the main reason why dams have failed unexpectedly. To prevent failures, designers suggested the use of a clay blanket placed under the upstream shoulder. However, for dams with soft clay cores, these underblankets could provide a route for a slip surface and that could lead to failure of the upstream shoulder. It was concluded that a safe arrangement for embankment dams includes the use of tipping gates or overturning gates which always fail at a required flood water level. Many have been installed in old and new dams around the world. 14 refs., 19 figs.

  3. Prevalence of ototoxic medication use among older adults in Beaver Dam, Wisconsin.

    Science.gov (United States)

    Joo, Yoonmee; Cruickshanks, Karen J; Klein, Barbara E K; Klein, Ronald; Hong, OiSaeng; Wallhagen, Margaret

    2018-01-01

    Drug-related ototoxicity may exacerbate presbycusis (age-related hearing loss); yet, few data are available on the prevalence of ototoxic medication use by older adults. The purposes of this study were to assess the impact of aging and ototoxicity on hearing loss, the prevalence of ototoxic medication use, and select characteristics associated with ototoxic medication use among older adults. Cross-sectional analyses were conducted using select variables extracted from the baseline and 10-year follow-up assessments of the two population-based epidemiological studies to compare two points in time. Ninety-one percent of the sample was taking a medication reported to be ototoxic. Nonsteroidal anti-inflammatory drugs were the most commonly used (75.2%), followed by acetaminophen (39.9%) and diuretics (35.6%). Hypertension, diabetes, cardiovascular disease, and history of smoking were associated with ototoxic medication use. Participants with hearing loss were taking a significantly greater number of ototoxic medications than those without hearing loss. Known ototoxic medications are widely used. Any subsequent ototoxicity may interact with age changes and a more severe hearing loss than that associated with only age. Nurse practitioners should inform older adults about the possibility of drug-related ototoxicity and monitor hearing acuity of all older adults taking known ototoxic medications.

  4. Beaver dams maintain fish biodiversity by increasing habitat heterogeneity throughout a low-gradient stream network

    Science.gov (United States)

    Smith, Joseph M.; Mather, Martha E.

    2013-01-01

    Understanding the relationship between heterogeneity and biodiversity is an active focus of ecological research. Although habitat heterogeneity is conceptually linked to biodiversity, the amount and configuration of heterogeneity that maintains biodiversity within ecosystems is not well understood, especially for an entire stream network.

  5. Small Drusen and Age-Related Macular Degeneration: The Beaver Dam Eye Study

    Directory of Open Access Journals (Sweden)

    Ronald Klein

    2015-03-01

    Full Text Available We tested the hypothesis that large areas of small hard drusen (diameter <63 µm and intermediate drusen (diameter 63–124 µm are associated with the incidence of age-related macular degeneration (AMD. Eyes of 3344 older adults with at least two consecutive visits spaced five years apart over a 20-year period were included. A 6-level severity scale, including no drusen, four levels of increasing area (from minimal (<2596 µm² to large (>9086 µm² of only small hard drusen, and intermediate drusen, was used. The five-year incidence of AMD was 3% in eyes at the start of the interval with no, minimal, small, and moderate areas of only small drusen and 5% and 25% for eyes with large area of only small drusen and intermediate drusen, respectively. Compared to eyes with a moderate area of small drusen, the odds ratio (OR of developing AMD in eyes with a large area of only small drusen was 1.8 (p < 0.001. Compared to eyes with large area of only small drusen, eyes with intermediate drusen had an OR of 5.5 (p < 0.001 of developing AMD. Our results are consistent with our hypothesis that large areas of only small drusen are associated with the incidence of AMD.

  6. Beaver Colony Density Trends on the Chequamegon-Nicolet National Forest, 1987 - 2013.

    Directory of Open Access Journals (Sweden)

    Christine A Ribic

    Full Text Available The North American beaver (Castor canadensis is a managed species in the United States. In northern Wisconsin, as part of the state-wide beaver management program, the Chequamegon-Nicolet National Forest removes beavers from targeted trout streams on U.S. Forest Service lands. However, the success of this management program has not been evaluated. Targeted removals comprise only 3% of the annual beaver harvest, a level of effort that may not affect the beaver population. We used colony location data along Forest streams from 1987-2013 (Nicolet, northeast Wisconsin and 1997-2013 (Chequamegon, northwest Wisconsin to assess trends in beaver colony density on targeted trout streams compared to non-targeted streams. On the Chequamegon, colony density on non-targeted trout and non-trout streams did not change over time, while colony density on targeted trout streams declined and then stabilized. On the Nicolet, beaver colony density decreased on both non-targeted streams and targeted trout streams. However, colony density on targeted trout streams declined faster. The impact of targeted trapping was similar across the two sides of the Forest (60% reduction relative to non-targeted trout streams. Exploratory analyses of weather influences found that very dry conditions and severe winters were associated with transient reductions in beaver colony density on non-targeted streams on both sides of the Forest. Our findings may help land management agencies weigh more finely calibrated beaver control measures against continued large-scale removal programs.

  7. Beaver colony density trends on the Chequamegon-Nicolet National Forest, 1987 – 2013

    Science.gov (United States)

    Ribic, Christine; Donner, Deahn M.; Beck, Albert J.; Rugg, David J.; Reinecke, Sue; Eklund, Dan

    2017-01-01

    The North American beaver (Castor canadensis) is a managed species in the United States. In northern Wisconsin, as part of the state-wide beaver management program, the Chequamegon-Nicolet National Forest removes beavers from targeted trout streams on U.S. Forest Service lands. However, the success of this management program has not been evaluated. Targeted removals comprise only 3% of the annual beaver harvest, a level of effort that may not affect the beaver population. We used colony location data along Forest streams from 1987–2013 (Nicolet, northeast Wisconsin) and 1997–2013 (Chequamegon, northwest Wisconsin) to assess trends in beaver colony density on targeted trout streams compared to non-targeted streams. On the Chequamegon, colony density on non-targeted trout and non-trout streams did not change over time, while colony density on targeted trout streams declined and then stabilized. On the Nicolet, beaver colony density decreased on both non-targeted streams and targeted trout streams. However, colony density on targeted trout streams declined faster. The impact of targeted trapping was similar across the two sides of the Forest (60% reduction relative to non-targeted trout streams). Exploratory analyses of weather influences found that very dry conditions and severe winters were associated with transient reductions in beaver colony density on non-targeted streams on both sides of the Forest. Our findings may help land management agencies weigh more finely calibrated beaver control measures against continued large-scale removal programs.

  8. Beaver Colony Density Trends on the Chequamegon-Nicolet National Forest, 1987 - 2013.

    Science.gov (United States)

    Ribic, Christine A; Donner, Deahn M; Beck, Albert J; Rugg, David J; Reinecke, Sue; Eklund, Dan

    2017-01-01

    The North American beaver (Castor canadensis) is a managed species in the United States. In northern Wisconsin, as part of the state-wide beaver management program, the Chequamegon-Nicolet National Forest removes beavers from targeted trout streams on U.S. Forest Service lands. However, the success of this management program has not been evaluated. Targeted removals comprise only 3% of the annual beaver harvest, a level of effort that may not affect the beaver population. We used colony location data along Forest streams from 1987-2013 (Nicolet, northeast Wisconsin) and 1997-2013 (Chequamegon, northwest Wisconsin) to assess trends in beaver colony density on targeted trout streams compared to non-targeted streams. On the Chequamegon, colony density on non-targeted trout and non-trout streams did not change over time, while colony density on targeted trout streams declined and then stabilized. On the Nicolet, beaver colony density decreased on both non-targeted streams and targeted trout streams. However, colony density on targeted trout streams declined faster. The impact of targeted trapping was similar across the two sides of the Forest (60% reduction relative to non-targeted trout streams). Exploratory analyses of weather influences found that very dry conditions and severe winters were associated with transient reductions in beaver colony density on non-targeted streams on both sides of the Forest. Our findings may help land management agencies weigh more finely calibrated beaver control measures against continued large-scale removal programs.

  9. Mechanics of slide dams

    International Nuclear Information System (INIS)

    Young, G.A.

    1970-01-01

    Studies which promote the use of nuclear energy for peaceful projects in engineering are sponsored by the Atomic Energy Commission under the Plowshare program. Specific projects being considered include the construction of harbors, canals, and dams. Of these projects, perhaps the most difficult to accomplish will be the latter. This paper which is in two parts considers the problems which are associated with the construction of slide dams with nuclear explosives. It examines first the characteristics of conventional earth and rock-fill dams which are based upon proven techniques developed after many years of experience. The characteristics of natural landslide dams are also briefly considered to identify potential problems that must be overcome by slide dam construction techniques. Second, the mechanics of slide dams as determined from small-scale laboratory studies are presented. It is concluded that slide dams can be constructed and that small-scale field tests and additional laboratory studies are justified. (author)

  10. Mechanics of slide dams

    Energy Technology Data Exchange (ETDEWEB)

    Young, G A [Engineering, Agbabian-Jacobsen Associates, Los Angeles (United States)

    1970-05-15

    Studies which promote the use of nuclear energy for peaceful projects in engineering are sponsored by the Atomic Energy Commission under the Plowshare program. Specific projects being considered include the construction of harbors, canals, and dams. Of these projects, perhaps the most difficult to accomplish will be the latter. This paper which is in two parts considers the problems which are associated with the construction of slide dams with nuclear explosives. It examines first the characteristics of conventional earth and rock-fill dams which are based upon proven techniques developed after many years of experience. The characteristics of natural landslide dams are also briefly considered to identify potential problems that must be overcome by slide dam construction techniques. Second, the mechanics of slide dams as determined from small-scale laboratory studies are presented. It is concluded that slide dams can be constructed and that small-scale field tests and additional laboratory studies are justified. (author)

  11. Fallot's tetralogy in a European beaver (Castor fiber).

    Science.gov (United States)

    Wenger, Sandra; Gull, Jessica; Glaus, Tony; Blumer, Serafin; Wimmershoff, Julia; Kranjc, Asja; Steinmetz, Hanspeter; Hatt, Jean-Michel

    2010-06-01

    A 20-mo-old, female, 9-kg European beaver (Castor fiber) presented with apathy, reduced appetite of 3-day duration and a grade 5/6 systolic heart murmur. Thoracic radiographs revealed a diffuse broncho-interstitial pattern suspicious for bronchopneumonia. The echocardiographic findings of a hypertrophied right ventricle, ventricular septal defect with overriding aorta, and infundibular pulmonic stenosis were consistent with Fallot's tetralogy. Even though the bronchopneumonia rather than the congenital cardiac defect was considered of primary importance for the presenting clinical signs, the latter was relevant for the decision not to continue any medical treatment. Both disease processes were confirmed on necropsy. Fallot's tetralogy, European beaver, Castor fiber, heart murmur, ultrasound.

  12. Tailings dams from the perspective of conventional dam engineering

    International Nuclear Information System (INIS)

    Szymanski, M.B.

    1999-01-01

    A guideline intended for conventional dams such as hydroelectric, water supply, flood control, or irrigation is used sometimes for evaluating the safety of a tailings dam. Differences between tailings dams and conventional dams are often substantial and, as such, should not be overlooked when applying the techniques or safety requirements of conventional dam engineering to tailings dams. Having a dam safety evaluation program developed specifically for tailings dams is essential, if only to reduce the chance of potential errors or omissions that might occur when relying on conventional dam engineering practice. This is not to deny the merits of using the Canadian Dam Safety Association Guidelines (CDSA) and similar conventional dam guidelines for evaluating the safety of tailings dams. Rather it is intended as a warning, and as a rationale underlying basic requirement of tailings dam emgineering: specific experience in tailings dams is essential when applying conventional dam engineering practice. A discussion is included that focuses on the more remarkable tailings dam safety practics. It is not addressed to a technical publications intended for such dams, or significantly different so that the use of conventional dam engineering practice would not be appropriate. The CDSA Guidelines were recently revised to include tailings dams. But incorporating tailings dams into the 1999 revision of the CDSA Guidelines is a first step only - further revision is necessary with respect to tailings dams. 11 refs., 2 tabs

  13. Radon-hazard potential the Beaver basin, Utah

    International Nuclear Information System (INIS)

    Bishop, C.E.

    1995-01-01

    Indoor-radon levels in the Beaver basin of southwestern Utah are the highest recorded to date in Utah, ranging from 17.5 to 495 picocuries per liter (pCi/L). Because the U.S. Environment Protection Agency considers indoor-radon levels above 4 pCi/L to represent a risk of lung cancer from long-term exposure, the Utah Geological Survey is preparing a radon-hazard-potential map for the area to help prioritize indoor testing and evaluate the need for radon-resistant construction. Radon is a chemically inert radioactive gas derived from the decay of uranium-238, which is commonly found in rocks and soils. Soil permeability, depth to ground water, and uranium/thorium content of source materials control the mobility and concentration of radon in the soil. Once formed, radon diffuses into the pore space of the soil and then to the atmosphere or into buildings by pressure-driven flow of air or additional diffusion. The Beaver basin has been a topographic and structural depression since late Miocene time. Paleocene to Miocene volcanic and igneous rocks border the basin. Uraniferous alluvial-fan, piedmont-slope, flood-plain, and lacustrine sediments derived from the surrounding volcanic rocks fill the basin. A soil-gas radon and ground radioactivity survey in the Beaver basin shows that soils have high levels of radon gas. In this survey, uranium concentrations range from 3 to 13 parts per million (ppm) and thorium concentrations range from 10 to 48 ppm. Radon concentrations in the soil gas ranged from 85 to 3,500 pCi/L. The highest concentrations of uranium, thorium, and radon gas and the highest radon-hazard-potential are in the well-drained permeable soils in the lower flood- plain deposits that underlie the city of Beaver

  14. Individual differences in maternal response to immune challenge predict offspring behavior: Contribution of environmental factors

    Science.gov (United States)

    Bronson, Stefanie L.; Ahlbrand, Rebecca; Horn, Paul S.; Kern, Joseph R.; Richtand, Neil M.

    2011-01-01

    Maternal infection during pregnancy elevates risk for schizophrenia and related disorders in offspring. Converging evidence suggests the maternal inflammatory response mediates the interaction between maternal infection, altered brain development, and behavioral outcome. The extent to which individual differences in the maternal response to immune challenge influence the development of these abnormalities is unknown. The present study investigated the impact of individual differences in maternal response to the viral mimic polyinosinic:polycytidylic acid (poly I:C) on offspring behavior. We observed significant variability in body weight alterations of pregnant rats induced by administration of poly I:C on gestational day 14. Furthermore, the presence or absence of maternal weight loss predicted MK-801 and amphetamine stimulated locomotor abnormalities in offspring. MK-801 stimulated locomotion was altered in offspring of all poly I:C treated dams; however, the presence or absence of maternal weight loss resulted in decreased and modestly increased locomotion, respectively. Adult offspring of poly I:C treated dams that lost weight exhibited significantly decreased amphetamine stimulated locomotion, while offspring of poly I:C treated dams without weight loss performed similarly to vehicle controls. Social isolation and increased maternal age predicted weight loss in response to poly I:C but not vehicle injection. In combination, these data identify environmental factors associated with the maternal response to immune challenge and functional outcome of offspring exposed to maternal immune activation. PMID:21255612

  15. Public safety around dams

    Energy Technology Data Exchange (ETDEWEB)

    Bourassa, H [Centre d' expertise hydrique du Quebec, Quebec, PQ (Canada)

    2009-07-01

    Fourty public dams are managed on a real-time basis by the Centre d'expertise hydrique du Quebec (CEHQ). This presentation described the public dams owned by the CEHQ and discussed the public safety measures at the dams. The dams serve various purposes, including protection against floods; industrial or drinking water supply; resort or recreational activities; hydroelectric development; and wildlife conservation. Trigger events were also discussed, such as the complaint at Rapides-des-Cedres dam and deaths that occurred in 2004 when water from a dam was released without warning. Several photographs were presented to illustrate that people were unaware of the danger. Initiatives aimed at raising awareness and studying public safety issues were discussed. A pilot project was launched and a permanent committee was created to evaluate all aspects of public safety at the dams owned by CEHQ. The first tasks of the committee were to establish requirements for waterway safety barriers, both upstream and downstream, for all public dams; to establish requirements for safety signage for all public dams; and to develop criteria to decide on safety signage at each dam. figs.

  16. Public safety around dams

    Energy Technology Data Exchange (ETDEWEB)

    Bourassa, H. [Centre d' expertise hydrique du Quebec, Quebec, PQ (Canada)

    2009-07-01

    Fourty public dams are managed on a real-time basis by the Centre d'expertise hydrique du Quebec (CEHQ). This presentation described the public dams owned by the CEHQ and discussed the public safety measures at the dams. The dams serve various purposes, including protection against floods; industrial or drinking water supply; resort or recreational activities; hydroelectric development; and wildlife conservation. Trigger events were also discussed, such as the complaint at Rapides-des-Cedres dam and deaths that occurred in 2004 when water from a dam was released without warning. Several photographs were presented to illustrate that people were unaware of the danger. Initiatives aimed at raising awareness and studying public safety issues were discussed. A pilot project was launched and a permanent committee was created to evaluate all aspects of public safety at the dams owned by CEHQ. The first tasks of the committee were to establish requirements for waterway safety barriers, both upstream and downstream, for all public dams; to establish requirements for safety signage for all public dams; and to develop criteria to decide on safety signage at each dam. figs.

  17. Maternal High Fat Feeding Does Not Have Long-Lasting Effects on Body Composition and Bone Health in Female and Male Wistar Rat Offspring at Young Adulthood

    Directory of Open Access Journals (Sweden)

    Paula M. Miotto

    2013-12-01

    Full Text Available High fat diets adversely affect body composition, bone mineral and strength, and alter bone fatty acid composition. It is unclear if maternal high fat (HF feeding permanently alters offspring body composition and bone health. Female rats were fed control (CON or HF diet for 10 weeks, bred, and continued their diets throughout pregnancy and lactation. Male and female offspring were studied at weaning and 3 months, following consumption of CON diet. At weaning, but not 3 months of age, male and female offspring from dams fed HF diet had lower lean mass and higher fat and bone mass, and higher femur bone mineral density (females only than offspring of dams fed CON diet. Male and female offspring femurs from dams fed HF diet had higher monounsaturates and lower n6 polyunsaturates at weaning than offspring from dams fed CON diet, where females from dams fed HF diet had higher saturates and lower n6 polyunsaturates at 3 months of age. There were no differences in strength of femurs or lumbar vertebrae at 3 months of age in either male or female offspring. In conclusion, maternal HF feeding did not permanently affect body composition and bone health at young adulthood in offspring.

  18. SELECTIVE FORAGING ON WOODY SPECIES BY THE BEAVER CASTOR FIBER, AND ITS IMPACT ON A RIPARIAN WILLOW FOREST

    NARCIS (Netherlands)

    NOLET, BA; HOEKSTRA, A; OTTENHEIM, MM

    1994-01-01

    Beavers were re-introduced in the Biesbosch, The Netherlands, a wood dominated by willows Salix spp. Conservationists expected that herbivory by beavers would enhance succession to a mixed broad-leaved forest. Willows formed the staple food of the beavers, but they removed only 1.4% of the standing

  19. A maternal "junk-food" diet reduces sensitivity to the opioid antagonist naloxone in offspring postweaning.

    Science.gov (United States)

    Gugusheff, Jessica R; Ong, Zhi Yi; Muhlhausler, Beverly S

    2013-03-01

    Perinatal exposure to a maternal "junk-food" diet has been demonstrated to increase the preference for palatable diets in adult offspring. We aimed to determine whether this increased preference could be attributed to changes in μ-opioid receptor expression within the mesolimbic reward pathway. We report here that mRNA expression of the μ-opioid receptor in the ventral tegmental area (VTA) at weaning was 1.4-fold (males) and 1.9-fold (females) lower in offspring of junk-food (JF)-fed rat dams than in offspring of dams fed a standard rodent diet (control) (Pjunk-food diet results in early desensitization of the opioid system which may explain the increased preference for junk food in these offspring.

  20. Spruce Lake Dam reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, G. [SGE Acres Ltd., Fredericton, NB (Canada); Barnard, J. [SGE Acres Ltd., St. John' s, NF (Canada); Vriezen, C. [City of Saint John, NF (Canada); Stephenson, M. [Jacques Whitford Environment Ltd., Fredericton, NB (Canada)

    2004-09-01

    Spruce Lake Dam was constructed in 1898 as part of the water supply system for Saint John, New Brunswick. The original dam was a 6 meter high, 140 meter long concrete gravity dam with an intake structure at its mid point and an overflow spillway at the left abutment. A rehabilitation project was launched in 2001 to bring the deteriorated dam into conformance with the dam safety guidelines of the Canadian Dam Association. The project criteria included minimal disruption to normal operation of water supply facilities and no negative effect on water quality. The project involved installation of a new low level outlet, removal of a gate house and water intake pipes, replacement of an access road culvert in the spillway channel, and raising the earth dam section by 1.8 meters to allow for increased water storage. The new raised section has an impervious core. The project also involved site and geotechnical investigations as well as hydrotechnical and environmental studies. This presentation described the final design of the remedial work and the environmental permitting procedures. Raising the operating level of the system proved successful as demonstrated by the fewer number of pumping days required after dam rehabilitation. The dam safety assessment under the Canadian Environmental Assessment Act began in April 2001, and the rehabilitation was completed by the end of 2002. 1 tab., 8 figs.

  1. Red fox, Vulpes vulpes, kills a European beaver, Castor fiber, kit

    OpenAIRE

    Kile, Nils B.; Nakken, Petter J.; Rosell, Frank; Espeland, Sigurd

    1996-01-01

    We observed an adult Red Fox (Vulpes vulpes) attack, kill and partially consume a 2-month-old female kit European Beaver (Castor fiber) near its lodge in Norway. The inner organs were consumed first. One adult beaver apparently attempted to frighten the fox away by tail-slapping.

  2. 75 FR 77826 - White River National Forest; Eagle County, CO; Beaver Creek Mountain Improvements

    Science.gov (United States)

    2010-12-14

    ... and/or affected individuals, organizations and governmental agencies will be used to identify resource... upcoming 2015 World Alpine Championships. In order for Beaver Creek to continue to host international... located at Beaver Creek. Hosting the 2015 International Skiing Federation (FIS) World Alpine Ski...

  3. Manipulating beaver (Castor canadensis) feeding responses to invasive tamarisk (Tamarix spp.).

    Science.gov (United States)

    Kimball, Bruce A; Perry, Kelly R

    2008-08-01

    To evaluate methods for promoting consumption of tamarisk plants by beavers (Castor canadensis), we determined the feeding responses by captive beavers to diets that contained tannins and sodium chloride (hereafter referred to as tamarisk diet). In two-choice tests, beavers consumed equivalent quantities of tamarisk diet and control diet. Treatment with polyethylene glycol and fructose did not increase beaver preferences for the tamarisk diet. When offered the choice of control diet and casein hydrolysate-treated control diet, beavers strongly avoided the latter, showing feeding deterring activity of casein hydrolysate. However, when tamarisk diet was the alternative to the deterrent treatment, beavers consumed similar quantities of the two diets. Finally, beaver foraging preferences for actual plant cuttings were assessed. Casein hydrolysate application to cuttings of black poplar (Populus nigra) and Scouler's willow (Salix scouleriana) reduced browsing of these highly preferred species and promoted a marked increase in browsing of tamarisk (Tamarix ramosissima). These results suggest that casein hydrolysate treatment of desirable riparian plant species such as Salix and Populus may promote beaver foraging of invasive tamarisk.

  4. 75 FR 40034 - Northeastern Tributary Reservoirs Land Management Plan, Beaver Creek, Clear Creek, Boone, Fort...

    Science.gov (United States)

    2010-07-13

    ... TENNESSEE VALLEY AUTHORITY Northeastern Tributary Reservoirs Land Management Plan, Beaver Creek...-managed public land on Beaver Creek, Clear Creek, Boone, Fort Patrick Henry, South Holston, Watauga, and... Proposed Land Use Alternative) identified in the final environmental impact statement (FEIS). Under the...

  5. Survey of beaver-related restoration practices in rangeland streams of the western USA

    Science.gov (United States)

    David S. Pilliod; Ashley T. Rohde; Susan Charnley; Rachael R. Davee; Jason B. Dunham; Hannah Gosnell; Gordon E. Grant; Mark B. Hausner; Justin L. Huntington; Caroline Nash

    2018-01-01

    Poor condition of many streams and concerns about future droughts in the arid and semi-arid western USA have motivated novel restoration strategies aimed at accelerating recovery and increasing water resources. Translocation of beavers into formerly occupied habitats, restoration activities encouraging beaver recolonization, and instream structures mimicking the...

  6. CARBON TRACE GASES IN LAKE AND BEAVER POND ICE NEAR THOMPSON, MANITOBA, CANADA

    Science.gov (United States)

    Concentrations of CO2, CO, and CH4 were measured in beaver pond and lake ice in April 1996 near Thompson, Manitoba to derive information on possible impacts of ice melting on corresponding atmospheric trace gas concentrations. CH4 concentrations in beaver pond and lake ice ranged...

  7. Habitat characteristics at den sites of the Point Arena mountain beaver (Aplodontia rufa nigra)

    Science.gov (United States)

    William J. Zielinski; John E. Hunter; Robin Hamlin; Keith M. Slauson; M. J. Mazurek

    2010-01-01

    The Point Arena mountain beaver (Aplodontia rufa nigra) is a federally listed endangered species, but has been the subject of few studies. Mountain beavers use burrows that include a single subterranean den. Foremost among the information needs for this subspecies is a description of the above-ground habitat features associated with dens. Using...

  8. Haematology and Serum Biochemistry Parameters and Variations in the Eurasian Beaver (Castor fiber).

    Science.gov (United States)

    Girling, Simon J; Campbell-Palmer, Roisin; Pizzi, Romain; Fraser, Mary A; Cracknell, Jonathan; Arnemo, Jon; Rosell, Frank

    2015-01-01

    Haematology parameters (N = 24) and serum biochemistry parameters (N = 35) were determined for wild Eurasian beavers (Castor fiber), between 6 months - 12 years old. Of the population tested in this study, N = 18 Eurasian beavers were from Norway and N = 17 originating from Bavaria but now living extensively in a reserve in England. All blood samples were collected from beavers via the ventral tail vein. All beavers were chemically restrained using inhalant isoflurane in 100% oxygen prior to blood sampling. Results were determined for haematological and serum biochemical parameters for the species and were compared between the two different populations with differences in means estimated and significant differences being noted. Standard blood parameters for the Eurasian beaver were determined and their ranges characterised using percentiles. Whilst the majority of blood parameters between the two populations showed no significant variation, haemoglobin, packed cell volume, mean cell haemoglobin and white blood cell counts showed significantly greater values (pbeavers or between sexually immature (beavers in the animals sampled. With Eurasian beaver reintroduction encouraged by legislation throughout Europe, knowledge of baseline blood values for the species and any variations therein is essential when assessing their health and welfare and the success or failure of any reintroduction program. This is the first study to produce base-line blood values and their variations for the Eurasian beaver.

  9. 76 FR 51469 - CSX Transportation, Inc.-Abandonment Exemption-in Beaver County, PA

    Science.gov (United States)

    2011-08-18

    ... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [Docket No. AB 55 (Sub-No. 708X)] CSX Transportation, Inc.--Abandonment Exemption--in Beaver County, PA CSX Transportation, Inc. (CSXT) has filed a... milepost PLK 2.39, in Koppel, Beaver County, Pa. The line traverses United States Postal Service Zip Code...

  10. Comeback of the beaver Castor fiber: An overview of old and new conservation problems

    NARCIS (Netherlands)

    Nolet, B.A.; Rosell, F.

    1998-01-01

    Due to over-hunting c. 1200 Eurasian beavers Castor fiber survived in eight relict populations in Europe and Asia at the beginning of the 20th century. Following hunting restrictions and translocation programmes in IS countries, the Eurasian beaver became re-established over much of its former

  11. Development and viability of a translocated beaver Castor fiber population in the Netherlands

    NARCIS (Netherlands)

    Nolet, B.A.; Baveco, J.M.

    1996-01-01

    We monitored survival, reproduction and emigration of a translocated beaver Castor fiber population in the Netherlands for five years and used a stochastic model to assess its viability. Between 1988 and 1991, 42 beavers were released in the Biesbosch National Park. The mortality was initially high

  12. Factors affecting scent-marking behaviour in Eurasion beaver (Castor fiber)

    NARCIS (Netherlands)

    Rosell, F.; Nolet, B.A.

    1997-01-01

    We tested the hypothesis that a main function of territory marking in Eurasian beaver (Castor fiber) is defense of the territory. The results showed that: (1) beaver colonies with close neighbors scent-mark more often than isolated ones; (2) the number of scent markings increased significantly with

  13. Milk transfer and tissue uptake of mercury in suckling offspring after exposure of lactating maternal guinea pigs to inorganic or methylmercury

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Minoru (Dept. of Public Health, St. Marianna Univ. School of Medicine, Kawasaki (Japan)); Watanabe, Chiho (Dept. of Environmental Health Sciences, Tohoku Univ. School of Medicine, Sendai (Japan)); Satoh, Hiroshi (Dept. of Environmental Health Sciences, Tohoku Univ. School of Medicine, Sendai (Japan)); Kishimoto, Tsuyoshi (Dept. of Public Health, St. Marianna Univ. School of Medicine, Kawasaki (Japan)); Yamamura, Yukio (Dept. of Public Health, St. Marianna Univ. School of Medicine, Kawasaki (Japan))

    1994-03-01

    Maternal guinea pigs were injected with mercuric chloride (HgCl[sub 2]; 1 mg Hg/kg body weight) or methylmercury (MeHg; 1 mg Hg/kg) 12 h after parturition, and exposure of the offspring to mercury (Hg) via breast milk were studied on days 3, 5 and 10 postpartum. Milk Hg concentrations were lower than maternal plasma Hg concentrations regardless of the form of Hg given to the dams. Milk Hg was higher in HgCl[sub 2]-treated dams than in MeHg-treated dams. In MeHg-treated dams, MeHg was separately determined. While the ratio of MeHg to T-Hg decreased in the dams' plasma, it did not in the milk. There was a strong correlation between milk and plasma T-Hg concentrations in HgCl[sub 2] treated dams. In the milk of MeHg-treated dams, the plasma MeHg concentrations correlated better than did the plasma T-Hg concentrations. In the offspring, regardless of the chemical forms of Hg given to the dams, the highest Hg concentrations were found in the kidney, followed by the liver and the brain. Brain Hg concentrations were, however, significantly higher in the offspring of MeHg-treated dams than in those of HgCl[sub 2]-treated dams. In addition, Hg levels in the major organs of the offspring of HgCl[sub 2]-treated dams peaked on day 5 postpartum, while those of MeHg-treated dams did not show a significant decrease up to day 10 postpartum. These facts indicate that the two chemical forms of Hg were transferred to the off-spring via the breast milk and were distributed differently, depending on the chemical form, to the off spring's tissues. (orig.)

  14. Exposure to a maternal cafeteria diet changes open-field behaviour in the developing offspring.

    Science.gov (United States)

    Speight, Abigail; Davey, William G; McKenna, Emily; Voigt, Jörg-Peter W

    2017-04-01

    The early postnatal period is a sensitive period in rodents as behavioural systems are developing and maturing during this time. However, little is currently known about the behavioural effects of feeding a hyper-energetic cafeteria diet (CD) during the lactational period when offspring behaviour is tested during early adolescence. To this end, 23days old offspring from dams (Wistar) fed on CD during lactation were tested in either the open-field or the elevated plus-maze for exploration and anxiety-related behaviour. On postnatal day 9, maternal behaviour and non-maternal behaviour of the dam was assessed. It was hypothesized that lactational CD feeding would reduce anxiety in the offspring. CD-fed dams had a higher energy intake, due to an overconsumption of sugars and fats. When offspring from these dams were exposed to the open field after weaning, their locomotor activity was increased. They entered the more aversive inner zone of the open-field after a shorter latency, made more entries into and spent more time in the inner zone. Anxiety-related behaviour was not affected upon exposure to the elevated plus maze, suggesting anxiolysis in the open-field only. Increased maternal licking/grooming behaviour could possibly contribute to the anxiolytic phenotype as observed in the offspring from the CD group. In conclusion, we demonstrate that lactational overfeeding impacts on the development of behaviour in the early adolescent rat. Copyright © 2016 ISDN. Published by Elsevier Ltd. All rights reserved.

  15. New finding of Trichinella britovi in a European beaver (Castor fiber) in Latvia.

    Science.gov (United States)

    Segliņa, Zanda; Bakasejevs, Eduards; Deksne, Gunita; Spuņģis, Voldemārs; Kurjušina, Muza

    2015-08-01

    We report the first finding of Trichinella britovi in a European beaver. In Latvia, beaver is a common game animal and frequently used in human diet. A high prevalence of Trichinella infections in Latvia is present in the most common hosts-carnivores and omnivores. In total, 182 European beaver muscle samples were tested for Trichinella larvae accordingly to the reference method of European Communities Commission Regulation (EC) No. 2075/2005 (2005). Trichinella britovi larvae were detected in one animal (prevalence 0.5%; intensity 5.92 larvae per gram of muscle). This finding suggests that the consumption of European beaver meat can be a risk to human health. Further studies are needed in order to determine if the present observation represents an isolated individual case or low prevalence of Trichinella infection in beavers.

  16. Beaver Evidence - Historical Range of Beaver in the State of California, with an emphasis on areas within the range of coho salmon and steelhead trout

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project examines historical, archaeological, and geological evidence to re-evaluate the existing management paradigm that beaver are non-native to most of...

  17. Resveratrol Intake During Pregnancy and Lactation Modulates the Early Metabolic Effects of Maternal Nutrition Differently in Male and Female Offspring.

    Science.gov (United States)

    Ros, Purificación; Díaz, Francisca; Freire-Regatillo, Alejandra; Argente-Arizón, Pilar; Barrios, Vicente; Argente, Jesús; Chowen, Julie A

    2018-02-01

    Poor maternal nutrition can have detrimental long-term consequences on energy homeostasis in the offspring. Resveratrol exerts antioxidant and antiobesity actions, but its impact during development remains largely unknown. We hypothesized that resveratrol intake during pregnancy and lactation could improve the effects of poor maternal nutrition on offspring metabolism. Wistar rats received a low-fat diet (LFD; 10.2% kcal from fat) or high-fat diet (HFD; 61.6% kcal from fat), with half of each group receiving resveratrol in their drinking water (50 mg/L) during pregnancy and lactation. Body weight (BW) of dams was measured at treatment onset and weaning [postnatal day (PND) 21] and of pups at birth and PND21, at which time dams and pups were euthanized. Although HFD dams consumed more energy, their BW at the end of lactation was unaffected. Mean litter size was not modified by maternal diet or resveratrol. At birth, male offspring from HFD and resveratrol (HFD + R) dams weighed less than those from LFD and resveratrol (LFD + R) dams. On PND21, pups of both sexes from HFD dams weighed more, had more visceral adipose tissue (VAT) and subcutaneous adipose tissue (SCAT), and had higher serum leptin levels than those from LFD dams. Resveratrol reduced BW, leptin, VAT, and SCAT, with females being more affected, but increased glycemia. Neuropeptide levels were unaffected by resveratrol. In conclusion, resveratrol intake during pregnancy and lactation decreased BW and adipose tissue content in offspring of dams on an HFD but did not affect offspring from LFD-fed dams, suggesting that the potential protective effects of resveratrol during gestation/lactation are diet dependent. Copyright © 2018 Endocrine Society.

  18. Habitat Evaluation Procedures (HEP) Report; Beaver Lake, Technical Report 2005.

    Energy Technology Data Exchange (ETDEWEB)

    Entz, Ray

    2005-05-01

    On August 14, 2003, the Habitat Evaluation Procedure (HEP) was used to determine baseline habitat suitability on the Beaver Lake property, an acquisition completed by the Kalispel Tribe of Indians in November 2002. Evaluation species and appropriate models include bald eagle, black-capped chickadee, Canada goose, mallard, muskrat, yellow warbler, and white-tailed deer. Habitat Suitability Index (HSI) values were visually estimated and agreed upon by all HEP team members. The Beaver Lake Project provides a total of 232.26 Habitat Units (HUs) for the species evaluated. Conifer forest habitat provides 136.58 HUs for bald eagle, black-capped chickadee, mallard, and white-tailed deer. Forested wetland habitat provides 20.02 HUs for bald eagle, black-caped chickadee, mallard, and white-tailed deer. Scrub-shrub wetland habitat provides 7.67 HUs for mallard, yellow warbler, and white-tailed deer. Grassland meadow provides 22.69 HUs for Canada goose and mallard. Emergent wetlands provide 35.04 HUs for Canada goose, mallard, and muskrat. Open water provided 10.26 HUs for Canada goose, mallard, and muskrat. The objective of using HEP at the Beaver Lake Project and other protected properties is to document the quality and quantity of available habitat for selected wildlife species. In this way, HEP provides information on the relative value of the same area at future points in time so that the effect of management activities on wildlife habitat can be quantified. When combined with other tools, the baseline HEP will be used to determine the most effective on-site management, restoration, and enhancement actions to increase habitat suitability for targeted species. The same process will be replicated every five years to quantitatively evaluate the effectiveness of management strategies in improving and maintaining habitat conditions while providing additional crediting to BPA for enhanced habitat values.

  19. WHIPJET progress on piping restraint elimination at Beaver Valley - 2

    International Nuclear Information System (INIS)

    Server, W.L.; Szy Slow Ski, J.J.; Goldstein, N.A.

    1986-01-01

    Fracture mechanics technology has advanced to the point that an engineering approach using the concept of leak-before-break in lieu of postulating double-ended pipe rupture is now possible. An approach based upon this fracture mechanics technology, termed WHIPJET, is currently being applied to Beaver Valley Power Station, Unit 2 for Duquesne Light Company. The WHIPJET philosophy is simple, conservative, and provides defense-in-depth arguments for high energy piping throughout the balance-of-plant. Progress being made in applying WHIPJET to several lines is presented

  20. Radionuclide uptake by beaver and ruffed grouse in the Serpent River basin

    International Nuclear Information System (INIS)

    Clulow, F.V.

    1988-12-01

    Radionuclide levels were measured in tissues, gut contents, and diet items of adult beaver and ruffed grouse from the Serpent River drainage basin (which contains the city of Elliot Lake) and control sites in Ontario, and in beaver and muskrat fetuses from females taken in the same basin. Levels of radium 226 in beaver bone, muscle and kidney were highest in animals from locations close to uranium tailings; liver levels did not vary by site. Grouse taken near Elliot Lake has higher bone levels of radium 226 than distant controls; levels in other tissues did not vary by site. Environmental radium 226 levels were within ranges previously reported at these or similar locations elsewhere; levels in beaver and grouse gut contents reflected levels in diet items. Fetal beaver tissues had higher radium 226 levels than maternal tissues; fetal liver tissue carried higher levels than other body tissues in general; fetal levels varied with maternal levels but also inversely with fetal size (and thus age). Although muskrat fetal liver had more radium 226 than other tissues, levels were lower than maternal bone levels. In two grouse and two beaver, selected for their higher tissue levels of radium 226, neither thorium 232 nor thorium 230 were detected in bone, muscle, or liver samples, however other radionuclides were measured: uranium 238 in beaver and grouse bone, muscle and liver; thorium 228 in beaver bone and grouse muscle; polonium 210 was found in bone, muscle, and liver of both beaver and grouse sampled (except in one grouse muscle sample); lead 210 was measurable only in beaver bone and in one grouse liver sample. Concentration ratios exceeded unity only between some vegetation items and beaver bone at the Elliot Lake site; between vegetation and other beaver tissues values were never more than 0.19. In grouse, the concentration ratios from trembling aspen leaves to bone was 1.04; from other diet items and to other tissues the values were less than unity. Estimated

  1. Chronic maternal low-protein diet in mice affects anxiety, night-time energy expenditure and sleep patterns, but not circadian rhythm in male offspring

    Science.gov (United States)

    Offspring of murine dams chronically fed a protein-restricted diet have an increased risk for metabolic and neurobehavioral disorders. Previously we showed that adult offspring, developmentally exposed to a chronic maternal low-protein (MLP) diet, had lower body and hind-leg muscle weights and decre...

  2. Dam safety operating guidelines

    International Nuclear Information System (INIS)

    Elsayed, E.; Leung, T.; Kirkham, A.; Lum, D.

    1990-01-01

    As part of Ontario Hydro's dam structure assessment program, the hydraulic design review of several river systems has revealed that many existing dam sites, under current operating procedures, would not have sufficient discharge capacity to pass the Inflow Design Flood (IDF) without compromising the integrity of the associated structures. Typical mitigative measures usually considered in dealing with these dam sites include structural alterations, emergency action plans and/or special operating procedures designed for extreme floods. A pilot study was carried out for the Madawaska River system in eastern Ontario, which has seven Ontario Hydro dam sites in series, to develop and evaluate the effectiveness of the Dam Safety Operating Guidelines (DSOG). The DSOG consist of two components: the flood routing schedules and the minimum discharge schedules, the former of which would apply in the case of severe spring flood conditions when the maximum observed snowpack water content and the forecast rainfall depth exceed threshold values. The flood routing schedules would identify to the operator the optimal timing and/or extent of utilizing the discharge facilities at each dam site to minimize the potential for dam failures cased by overtopping anywhere in the system. It was found that the DSOG reduced the number of structures overtopped during probable maximum flood from thirteen to four, while the number of structures that could fail would be reduced from seven to two. 8 refs., 4 figs., 3 tabs

  3. Severe Maternal Hyperglycemia Exacerbates the Development of Insulin Resistance and Fatty Liver in the Offspring on High Fat Diet

    Directory of Open Access Journals (Sweden)

    Yong Song

    2012-01-01

    Full Text Available Background. Adverse maternal environments may predispose the offspring to metabolic syndrome in adulthoods, but the underlying mechanism has not been fully understood. Methods. Maternal hyperglycemia was induced by streptozotocin (STZ injection while control (CON rats received citrate buffer. Litters were adjusted to eight pups per dam and then weaned to standard diet. Since 13 weeks old, a subset of offspring from STZ and CON dams were switched to high fat diet (HFD for another 13 weeks. Glucose and insulin tolerance tests (GTT and ITT and insulin secretion assay were performed; serum levels of lipids and leptin were measured. Hepatic fat accumulation and islet area were evaluated through haematoxylin and eosin staining. Results. STZ offspring exhibited lower survival rate, lower birth weights, and growth inhibition which persisted throughout the study. STZ offspring on HFD showed more severe impairment in GTT and ITT, and more profound hepatic steatosis and more severe hyperlipidemia compared with CON-HFD rats. Conclusions. Offspring from diabetic dams would be prone to exhibit low birth weight and postnatal growth inhibition, but could maintain normal glucose tolerance and insulin sensitivity. HFD accelerates development of insulin resistance in the offspring of diabetic dams mainly via a compensatory response of islets.

  4. Haematology and Serum Biochemistry Parameters and Variations in the Eurasian Beaver (Castor fiber.

    Directory of Open Access Journals (Sweden)

    Simon J Girling

    Full Text Available Haematology parameters (N = 24 and serum biochemistry parameters (N = 35 were determined for wild Eurasian beavers (Castor fiber, between 6 months - 12 years old. Of the population tested in this study, N = 18 Eurasian beavers were from Norway and N = 17 originating from Bavaria but now living extensively in a reserve in England. All blood samples were collected from beavers via the ventral tail vein. All beavers were chemically restrained using inhalant isoflurane in 100% oxygen prior to blood sampling. Results were determined for haematological and serum biochemical parameters for the species and were compared between the two different populations with differences in means estimated and significant differences being noted. Standard blood parameters for the Eurasian beaver were determined and their ranges characterised using percentiles. Whilst the majority of blood parameters between the two populations showed no significant variation, haemoglobin, packed cell volume, mean cell haemoglobin and white blood cell counts showed significantly greater values (p<0.01 in the Bavarian origin population than the Norwegian; neutrophil counts, alpha 2 globulins, cholesterol, sodium: potassium ratios and phosphorus levels showed significantly (p<0.05 greater values in Bavarian versus Norwegian; and potassium, bile acids, gamma globulins, urea, creatinine and total calcium values levels showed significantly (p<0.05 greater values in Norwegian versus Bavarian relict populations. No significant differences were noted between male and female beavers or between sexually immature (<3 years old and sexually mature (≥3 years old beavers in the animals sampled. With Eurasian beaver reintroduction encouraged by legislation throughout Europe, knowledge of baseline blood values for the species and any variations therein is essential when assessing their health and welfare and the success or failure of any reintroduction program. This is the first study to produce

  5. Ancient mitochondrial DNA and the genetic history of Eurasian beaver (Castor fiber) in Europe.

    Science.gov (United States)

    Horn, Susanne; Prost, Stefan; Stiller, Mathias; Makowiecki, Daniel; Kuznetsova, Tatiana; Benecke, Norbert; Pucher, Erich; Hufthammer, Anne K; Schouwenburg, Charles; Shapiro, Beth; Hofreiter, Michael

    2014-04-01

    After centuries of human hunting, the Eurasian beaver Castor fiber had disappeared from most of its original range by the end of the 19th century. The surviving relict populations are characterized by both low genetic diversity and strong phylogeographical structure. However, it remains unclear whether these attributes are the result of a human-induced, late Holocene bottleneck or already existed prior to this reduction in range. To investigate genetic diversity in Eurasian beaver populations during the Holocene, we obtained mitochondrial control region DNA sequences from 48 ancient beaver samples and added 152 modern sequences from GenBank. Phylogeographical analyses of the data indicate a differentiation of European beaver populations into three mitochondrial clades. The two main clades occur in western and eastern Europe, respectively, with an early Holocene contact zone in eastern Europe near a present-day contact zone. A divergent and previously unknown clade of beavers from the Danube Basin survived until at least 6000 years ago, but went extinct during the transition to modern times. Finally, we identify a recent decline in effective population size of Eurasian beavers, with a stronger bottleneck signal in the western than in the eastern clade. Our results suggest that the low genetic diversity and the strong phylogeographical structure in recent beavers are artefacts of human hunting-associated population reductions. While beaver populations have been growing rapidly since the late 19th century, genetic diversity within modern beaver populations remains considerably reduced compared to what was present prior to the period of human hunting and habitat reduction.

  6. Decreasing maternal myostatin programs adult offspring bone strength in a mouse model of osteogenesis imperfecta.

    Science.gov (United States)

    Oestreich, Arin K; Kamp, William M; McCray, Marcus G; Carleton, Stephanie M; Karasseva, Natalia; Lenz, Kristin L; Jeong, Youngjae; Daghlas, Salah A; Yao, Xiaomei; Wang, Yong; Pfeiffer, Ferris M; Ellersieck, Mark R; Schulz, Laura C; Phillips, Charlotte L

    2016-11-22

    During fetal development, the uterine environment can have effects on offspring bone architecture and integrity that persist into adulthood; however, the biochemical and molecular mechanisms remain unknown. Myostatin is a negative regulator of muscle mass. Parental myostatin deficiency (Mstn tm1Sjl/+ ) increases muscle mass in wild-type offspring, suggesting an intrauterine programming effect. Here, we hypothesized that Mstn tm1Sjl/+ dams would also confer increased bone strength. In wild-type offspring, maternal myostatin deficiency altered fetal growth and calvarial collagen content of newborn mice and conferred a lasting impact on bone geometry and biomechanical integrity of offspring at 4 mo of age, the age of peak bone mass. Second, we sought to apply maternal myostatin deficiency to a mouse model with osteogenesis imperfecta (Col1a2 oim ), a heritable connective tissue disorder caused by abnormalities in the structure and/or synthesis of type I collagen. Femora of male Col1a2 oim/+ offspring from natural mating of Mstn tm1Sjl/+ dams to Col1a2 oim/+ sires had a 15% increase in torsional ultimate strength, a 29% increase in tensile strength, and a 24% increase in energy to failure compared with age, sex, and genotype-matched offspring from natural mating of Col1a2 oim/+ dams to Col1a2 oim/+ sires. Finally, increased bone biomechanical strength of Col1a2 oim/+ offspring that had been transferred into Mstn tm1Sjl/+ dams as blastocysts demonstrated that the effects of maternal myostatin deficiency were conferred by the postimplantation environment. Thus, targeting the gestational environment, and specifically prenatal myostatin pathways, provides a potential therapeutic window and an approach for treating osteogenesis imperfecta.

  7. Maternal high fat diet alters skeletal muscle mitochondrial catalytic activity in adult male rat offspring.

    Directory of Open Access Journals (Sweden)

    Chantal Anne Pileggi

    2016-11-01

    Full Text Available A maternal high-fat (HF diet during pregnancy can lead to metabolic compromise such as insulin resistance in adult offspring. Skeletal muscle mitochondrial dysfunction is one mechanism contributing to metabolic impairments in insulin resistant states. Therefore, the present study aimed to investigate whether mitochondrial dysfunction is evident in metabolically compromised offspring born to HF-fed dams. Sprague-Dawley dams were randomly assigned to receive a purified control diet (CD; 10% kcal from fat or a high fat diet (HFD; 45% kcal from fat for 10 days prior to mating, throughout pregnancy and during lactation. From weaning, all male offspring received a standard chow diet and soleus muscle was collected at day 150. Expression of the mitochondrial transcription factors nuclear respiratory factor-1 (NRF1 and mitochondrial transcription factor A (mtTFA were downregulated in HF offspring. Furthermore, genes encoding the mitochondrial electron transport system (ETS respiratory complex subunits were supressed in HF offspring. Moreover, protein expression of the complex I subunit, NDUFB8, was downregulated in HF offspring (36%, which was paralleled by decreased maximal catalytic linked activity of complex I and III (40%. Together, these results indicate that exposure to a maternal HF diet during development may elicit lifelong mitochondrial alterations in offspring skeletal muscle.

  8. Predicting spread of invasive exotic plants into de-watered reservoirs following dam removal on the Elwha River, Olympic National Park, Washington

    Science.gov (United States)

    Woodward, Andrea; Torgersen, Christian E.; Chenoweth, Joshua; Beirne, Katherine; Acker, Steve

    2011-01-01

    The National Park Service is planning to start the restoration of the Elwha River ecosystem in Olympic National Park by removing two high head dams beginning in 2011. The potential for dispersal of exotic plants into dewatered reservoirs following dam removal, which would inhibit restoration of native vegetation, is of great concern. We focused on predicting long-distance dispersal of invasive exotic plants rather than diffusive spread because local sources of invasive species have been surveyed. We included the long-distance dispersal vectors: wind, water, birds, beavers, ungulates, and users of roads and trails. Using information about the current distribution of invasive species from two surveys, various geographic information system techniques and models, and statistical methods, we identified high-priority areas for Park staff to treat prior to dam removal, and areas of the dewatered reservoirs at risk after dam removal.

  9. The Eurasian beaver (Castor fiber) is apparently not a host to blood parasites in Norway.

    Science.gov (United States)

    Cross, Hannah B; Campbell-Palmer, Róisín; Girling, Simon; Rosell, Frank

    2012-11-23

    Parasites can alter the physiology and behaviour of host species and negatively impact on their fitness thus affecting population densities. This is the first investigation into the presence of blood parasites in the Eurasian beaver (Castor fiber); a species that has been the subject of many translocation and reintroduction programmes. Two hundred and seventy blood slides prepared from the blood of 27 beavers from southern Norway were microscopically analysed for the presence of blood parasites. This study reports an absence of blood parasites in the Norwegian Eurasian beavers sampled. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Allegheny County Dam Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset shows the point locations of dams in Allegheny County. If viewing this description on the Western Pennsylvania Regional Data Center’s open data portal...

  11. High Folic Acid Intake during Pregnancy Lowers Body Weight and Reduces Femoral Area and Strength in Female Rat Offspring

    Directory of Open Access Journals (Sweden)

    Pedro S. P. Huot

    2013-01-01

    Full Text Available Rats fed gestational diets high in multivitamin or folate produce offspring of altered phenotypes. We hypothesized that female rat offspring born to dams fed a gestational diet high in folic acid (HFol have compromised bone health and that feeding the offspring the same HFol diet attenuates these effects. Pregnant rats were fed diets with either recommended folic acid (RFol or 10-fold higher folic acid (HFol amounts. Female offspring were weaned to either the RFol or HFol diet for 17 weeks. HFol maternal diet resulted in lower offspring body weights (6%, P=0.03 and, after adjusting for body weight and femoral length, smaller femoral area (2%, P=0.03, compared to control diet. After adjustments, HFol pup diet resulted in lower mineral content (7%, P=0.01 and density (4%, P=0.002 of lumbar vertebra 4 without differences in strength. An interaction between folate content of the dam and pup diets revealed that a mismatch resulted in lower femoral peak load strength (P=0.01 and stiffness (P=0.002. However, the match in folate content failed to prevent lower weight gain. In conclusion, HFol diets fed to rat dams and their offspring affect area and strength of femurs and mineral quantity but not strength of lumbar vertebrae in the offspring.

  12. The effects of maternal corticosterone levels on offspring behavior in fast- and slow-growth garter snakes (Thamnophis elegans).

    Science.gov (United States)

    Robert, Kylie A; Vleck, Carol; Bronikowski, Anne M

    2009-01-01

    During embryonic development, viviparous offspring are exposed to maternally circulating hormones. Maternal stress increases offspring exposure to corticosterone and this hormonal exposure has the potential to influence developmental, morphological and behavioral traits of the resulting offspring. We treated pregnant female garter snakes (Thamnophis elegans) with low levels of corticosterone after determining both natural corticosterone levels in the field and pre-treatment levels upon arrival in the lab. Additional measurements of plasma corticosterone were taken at days 1, 5, and 10 during the 10-day exposure, which occurred during the last third of gestation (of 4-month gestation). These pregnant snakes were from replicate populations of fast- and slow-growth ecotypes occurring in Northern California, with concomitant short and long lifespans. Field corticosterone levels of pregnant females of the slow-growth ecotype were an order of magnitude higher than fast-growth dams. In the laboratory, corticosterone levels increased over the 10 days of corticosterone manipulation for animals of both ecotypes, and reached similar plateaus for both control and treated dams. Despite similar plasma corticosterone levels in treated and control mothers, corticosterone-treated dams produced more stillborn offspring and exhibited higher total reproductive failure than control dams. At one month of age, offspring from fast-growth females had higher plasma corticosterone levels than offspring from slow-growth females, which is opposite the maternal pattern. Offspring from corticosterone-treated mothers, although unaffected in their slither speed, exhibited changes in escape behaviors and morphology that were dependent upon maternal ecotype. Offspring from corticosterone-treated fast-growth females exhibited less anti-predator reversal behavior; offspring from corticosterone-treated slow-growth females exhibited less anti-predator tail lashing behavior.

  13. Teton Dam failure

    Energy Technology Data Exchange (ETDEWEB)

    Snorteland, N. [United States Dept. of the Interior, Washington, DC (United States). Bureau of Reclamation

    2009-07-01

    This case summary discussed an internal erosion failure that occurred at the embankment foundation of Teton Dam. The project was designed as a run-of-the-river power generation facility and to provide irrigation, flood protection, and power generation to the lower Teton region of southern Idaho. The dam site was located next to the eastern Snake River plain, a volcanic filled depression. The foundation's cutoff trench was excavated into the bedrock along the length of the dam. The dam was designed as a zoned earthfill with a height of 305 feet. A trench made of low plasticity windblown silt was designed to connect the embankment core to the rock foundation. Seeps were noted in 1976, and a leak was observed near the toe of the dam. A wet spot appeared on the downstream face of the dam at elevation 5200. A sinkhole then developed. The embankment crest collapsed, and the dam breached. Peak outflow was estimated at 1,000,000 cfs. The failure was attributed to a lack of communication between designers, a failure to understand geologic information about the region, and an insufficient review of designs and specifications by designers and field personnel. No monitoring instrumentation was installed in the embankment. Approximately 300 square miles were inundated, and 25,000 people were displaced. Eleven people were killed. A review group noted that the rock surface was not adequately sealed, and that the dam failed as a result of inadequate protection of the impervious core material from internal erosion. 42 figs.

  14. Simulation modeling to understand how selective foraging by beaver can drive the structure and function of a willow community

    Science.gov (United States)

    Peinetti, H.R.; Baker, B.W.; Coughenour, M.B.

    2009-01-01

    Beaver-willow (Castor-Salix) communities are a unique and vital component of healthy wetlands throughout the Holarctic region. Beaver selectively forage willow to provide fresh food, stored winter food, and construction material. The effects of this complex foraging behavior on the structure and function of willow communities is poorly understood. Simulation modeling may help ecologists understand these complex interactions. In this study, a modified version of the SAVANNA ecosystem model was developed to better understand how beaver foraging affects the structure and function of a willow community in a simulated riparian ecosystem in Rocky Mountain National Park, Colorado (RMNP). The model represents willow in terms of plant and stem dynamics and beaver foraging in terms of the quantity and quality of stems cut to meet the energetic and life history requirements of beaver. Given a site where all stems were equally available, the model suggested a simulated beaver family of 2 adults, 2 yearlings, and 2 kits required a minimum of 4 ha of willow (containing about10 stems m-2) to persist in a steady-state condition. Beaver created a willow community where the annual net primary productivity (ANPP) was 2 times higher and plant architecture was more diverse than the willow community without beaver. Beaver foraging created a plant architecture dominated by medium size willow plants, which likely explains how beaver can increase ANPP. Long-term simulations suggested that woody biomass stabilized at similar values even though availability differed greatly at initial condition. Simulations also suggested that willow ANPP increased across a range of beaver densities until beaver became food limited. Thus, selective foraging by beaver increased productivity, decreased biomass, and increased structural heterogeneity in a simulated willow community.

  15. Maternal obesity and post-natal high fat diet disrupt hepatic circadian rhythm in rat offspring

    Science.gov (United States)

    Offspring of obese (Ob) rat dams gain greater body wt and fat mass when fed high-fat diet (HFD) as compared to controls. Alterations of diurnal circadian rhythm are known to detrimentally impact metabolically active tissues such as liver. We sought to determine if maternal obesity (MOb) leads to p...

  16. Both high and low maternal salt intake in pregnancy alter kidney development in the offspring.

    Science.gov (United States)

    Koleganova, Nadezda; Piecha, Grzegorz; Ritz, Eberhard; Becker, Luis Eduardo; Müller, Annett; Weckbach, Monika; Nyengaard, Jens Randel; Schirmacher, Peter; Gross-Weissmann, Marie-Luise

    2011-08-01

    In humans, low glomerular numbers are related to hypertension, cardiovascular, and renal disease in adult life. The present study was designed 1) to explore whether above- or below-normal dietary salt intake during pregnancy influences nephron number and blood pressure in the offspring and 2) to identify potential mechanisms in kidney development modified by maternal sodium intake. Sprague-Dawley rats were fed low (0.07%)-, intermediate (0.51%)-, or high (3.0%)-sodium diets during pregnancy and lactation. The offspring were weaned at 4 wk and subsequently kept on a 0.51% sodium diet. The kidney structure was assessed at postnatal weeks 1 and 12 and the expression of proteins of interest at term and at week 1. Blood pressure was measured in male offspring by telemetry from postnatal month 2 to postnatal month 9. The numbers of glomeruli at weeks 1 and 12 were significantly lower and, in males, telemetrically measured mean arterial blood pressure after month 5 was higher in offspring of dams on a high- or low- compared with intermediate-sodium diet. A high-salt diet was paralleled by higher concentrations of marinobufagenin in the amniotic fluid and an increase in the expression of both sprouty-1 and glial cell-derived neutrophic factor in the offspring's kidney. The expression of FGF-10 was lower in offspring of dams on a low-sodium diet, and the expression of Pax-2 and FGF-2 was lower in offspring of dams on a high-sodium diet. Both excessively high and excessively low sodium intakes during pregnancy modify protein expression in offspring kidneys and reduce the final number of glomeruli, predisposing the risk of hypertension later in life.

  17. Effect of honey on the reproductive system of male rat offspring exposed to prenatal restraint stress.

    Science.gov (United States)

    Haron, M N; Mohamed, M

    2016-06-01

    Exposure to prenatal stress is associated with impaired reproductive function in male rat offspring. Honey is traditionally used by the Malays for enhancement of fertility. The aim of this study was to determine the effect of honey on reproductive system of male rat offspring exposed to prenatal restraint stress. Dams were divided into four groups (n = 10/group): control, honey, stress and honey + stress groups. Dams from honey and honey + stress groups received oral honey (1.2 g kg(-1) body weight) daily from day 1 of pregnancy, meanwhile dams from stress and honey + stress groups were subjected to restraint stress (three times per day) from day 11 of pregnancy until delivery. At 10 weeks old, each male rat offspring was mated with a regular oestrus cycle female. Male sexual behaviour and reproductive performance were evaluated. Then, male rats were euthanised for assessment on reproductive parameters. Honey supplementation during prenatal restraint stress significantly increased testis and epididymis weights as well as improved the percentages of abnormal spermatozoa and sperm motility in male rat offspring. In conclusion, this study might suggest that supplementation of honey during pregnancy seems to reduce the adverse effects of restraint stress on reproductive organs weight and sperm parameters in male rat offspring. © 2015 Blackwell Verlag GmbH.

  18. Ground-Water-Quality Data for Selected Wells in the Beaver Creek Watershed, West Tennessee

    National Research Council Canada - National Science Library

    Williams, Shannon D

    1996-01-01

    In 1993 the U.S. Geological Survey, in cooperation with the Tennessee Department of Environment and Conservation, began an investigation of the quality of ground water in the Beaver Creek watershed in West Tennessee...

  19. Collection of Short Papers on the Beaver Creek Watershed Study in West Tennessee, 1989-94

    National Research Council Canada - National Science Library

    Doyle, Jr., W. H; Baker, Eva G

    1995-01-01

    In 1989, the U.S. Geological Survey began a long-term research project to evaluate the effect of agricultural activities on water quality and the effectiveness of agricultural best management practices in the Beaver...

  20. Beaver-mediated methane emission: The effects of population growth in Eurasia and the Americas.

    Science.gov (United States)

    Whitfield, Colin J; Baulch, Helen M; Chun, Kwok P; Westbrook, Cherie J

    2015-02-01

    Globally, greenhouse gas budgets are dominated by natural sources, and aquatic ecosystems are a prominent source of methane (CH(4)) to the atmosphere. Beaver (Castor canadensis and Castor fiber) populations have experienced human-driven change, and CH(4) emissions associated with their habitat remain uncertain. This study reports the effect of near extinction and recovery of beavers globally on aquatic CH4 emissions and habitat. Resurgence of native beaver populations and their introduction in other regions accounts for emission of 0.18-0.80 Tg CH(4) year(-1) (year 2000). This flux is approximately 200 times larger than emissions from the same systems (ponds and flowing waters that became ponds) circa 1900. Beaver population recovery was estimated to have led to the creation of 9500-42 000 km(2) of ponded water, and increased riparian interface length of >200 000 km. Continued range expansion and population growth in South America and Europe could further increase CH(4) emissions.

  1. Electrofishing method improves evaluation of amphibian larvae abundance: a case of "beaver rivers".

    Science.gov (United States)

    Dgebuadze, Yury Y; Bashinskiy, Ivan V

    2017-07-01

    There are many locations in Russia where Eurasian beaver (Castor fiber) populations have been restored. As a keystone species, beavers provide wide-ranging direct and indirect impacts on aquatic ecosystems. In particular, beaver-created ponds are sites for spawning and nursery places for tadpoles of the brown frogs (genus Rana). Because of such impacts, study techniques for assessing aquatic organism abundance are being developed. We compared two methods for estimating tadpole abundance: traditional catches by dipnet and electrofishing. Our results show that the dipnet catch data for the shallower ponds with larger water surface area were five times lower than that obtained by electrofishing. Therefore, we conclude that dipnet catches are not suitable for comparing the relative abundance of tadpoles in the two beaver ponds that were studied. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  2. Beaver Valley Power Station and Shippingport Atomic Power Station. 1977 annual environmental report: radiological. Volume 2

    International Nuclear Information System (INIS)

    1978-01-01

    The environmental monitoring conducted during 1977 in the vicinity of the Beaver Valley Power Station and the Shippingport Atomic Power Station is described. The environmental monitoring program consists of onsite sampling of water, gaseous, and air effluents, as well as offsite monitoring of water, air, river sediments, and radiation levels in the vicinity of the site. The report discusses releases of small quantities of radioactivity to the Ohio River from the Beaver Valley Power Station and Shippingport Atomic Power Station during 1977

  3. Effect of administration of antibiotics peripartum to wistar rats on bile acid profiles in offspring

    DEFF Research Database (Denmark)

    Clement Thaarup, Ida; Roager, Henrik Munch; Tulstrup, Monica Vera-Lise

    2016-01-01

    Vertical transmission of the maternal microbiota is assumed to be crucial for the offspring’s development. A disrupted microbiota composition leading to an altered metabolic activity of the microbiota can affect bile acid profiles, which are known to influence host metabolism. Here, we examined...... whether perturbation of the maternal gut microbiota during pregnancy, induced by administration of either amoxicillin or vancomycin to pregnant rats, influenced bile acid profiles in the offspring. The dams were treated with antibiotics from 8 days before the dams gave birth and continued until weaning (4...... weeks later). Blood samples were collected from offspring at ages 2, 4 and 14 weeks, and from dams at the end of treatment. From these blood samples, bile acids were extracted and 22 bile acids were quantified by targeted liquid chromatography mass spectrometry. Comparing the serum bile acid profiles...

  4. Population genetic structure in natural and reintroduced beaver (Castor fiber populations in Central Europe

    Directory of Open Access Journals (Sweden)

    Kautenburger, R.

    2008-12-01

    Full Text Available Castor fiber Linnaeus, 1758 is the only indigenous species of the genus Castor in Europe and Asia. Due to extensive hunting until the beginning of the 20th century, the distribution of the formerly widespread Eurasian beaver was dramatically reduced. Only a few populations remained and these were in isolated locations, such as the region of the German Elbe River. The loss of genetic diversity in small or captive populations throughgenetic drift and inbreeding is a severe conservation problem. However, the reintroduction of beaver populations from several regions in Europe has shown high viability and populations today are growing fast. In the present study we analysed the population genetic structure of a natural and two reintroduced beaver populations in Germany and Austria. Furthermore, we studied the genetic differentiation between two beaver species, C. fiber and the American beaver (C. canadensis, using RAPD (Random Amplified Polymorphic DNA as a genetic marker. The reintroduced beaver populations of different origins and the autochthonous population of the Elbe River showed a similar low genetic heterogeneity. There was an overall high genetic similarity in the species C. fiber, and no evidence was found for a clear subspecific structure in the populations studied.

  5. Effects of ethanol on offspring of C57BL/6J mice alcoholized during gestation

    Directory of Open Access Journals (Sweden)

    Grinfeld Hermann

    1999-01-01

    Full Text Available The effects of chronic alcohol consumption during pregnancy were analysed in the gestation and offspring of alcoholized mice. Female C57BL/6J mice were placed overnight with stud males and the presence of a sperm plug in the next morning indicated the onset of gestation. Pregnant mice were distributed in two weight-matched groups. In the alcoholized group, the mice received a high protein liquid diet ad libitum containing 27.5% of ethanol-derived calories (5.28% v/v from gestation day 5 to 19. The control group received the same volume of diet containing isocaloric amounts of maltose-dextrin substituted for ethanol. After postnatal day zero, the dams received food pellets and tap water ad libitum. On postnatal day 6 the pups were counted and weighed at variable intervals up to the 60th day of life. The majority of the pregnant dams that have received ethanol completed the gestational period, and the chronic consumption of alcohol did not interfere with the number of dams that gave birth. The alcoholized and control dams gained an equivalent weight and consumed an equivalent volume of diet throughout the gestation. The number of pups from alcohol diet dams was 46,26% smaller compared with the control group. There were less male than female pups in the offspring of alcoholized mice. Teratogeny like gastroschisis and limb malformation were present in the offspring of alcoholized dams. The body weight of the offspring of alcoholized mice increased from the 18th to the 36th postnatal day.

  6. Moderate exercise during pregnancy in Wistar rats alters bone and body composition of the adult offspring in a sex-dependent manner.

    Directory of Open Access Journals (Sweden)

    Brielle V Rosa

    Full Text Available Exercise during pregnancy may have long-lasting effects on offspring health. Musculoskeletal growth and development, metabolism, and later-life disease risk can all be impacted by the maternal environment during pregnancy. The skeleton influences glucose handling through the actions of the bone-derived hormone osteocalcin. The purpose of this study was to test the effects of moderate maternal exercise during pregnancy on the bone and body composition of the offspring in adult life, and to investigate the role of osteocalcin in these effects. Groups of pregnant Wistar rats either performed bipedal standing exercise to obtain food/water throughout gestation but not lactation, or were fed conventionally. Litters were reduced to 8/dam and pups were raised to maturity under control conditions. Whole body dual-energy x-ray absorptiometry, and ex vivo peripheral quantitative computed tomography scans of the right tibia were performed. At study termination blood and tissue samples were collected. Serum concentrations of fully and undercarboxylated osteocalcin were measured, and the relative expression levels of osteocalcin, insulin receptor, Forkhead box transcription factor O1, and osteotesticular protein tyrosine phosphatase mRNA were quantified. Body mass did not differ between the offspring of exercised and control dams, but the male offspring of exercised dams had a greater % fat and lower % lean than controls (p=0.001 and p=0.0008, respectively. At the mid-tibial diaphysis, offspring of exercised dams had a lower volumetric bone mineral density than controls (p=0.01 and in the male offspring of exercised dams the bone: muscle relationship was fundamentally altered. Serum concentrations of undercarboxylated osteocalcin were significantly greater in the male offspring of exercised dams than in controls (p=0.02; however, the relative expression of the measured genes did not differ between groups. These results suggest that moderate exercise during

  7. Use of linear and areal habitat models to establish and distribute beaver Castor fiber harvest quotas in Norway

    Directory of Open Access Journals (Sweden)

    Howard Parker

    2013-12-01

    Full Text Available In Norway the Eurasian beaver Castor fiber harvest is quota-regulated. Once the annual quota for each municipality has been determined it is distributed to landowner-organized beaver management units. Municipal wildlife managers can choose between two distributional models: the traditional “areal model” whereby each management unit receives its portion of the municipal quota based on the relative area of beaver habitat within the township that it contains, or the more recently developed “linear model” based on the relative length of beaver-utilized shoreline it contains. The linear model was developed in an attempt to increase the precision of the quota distribution process and is based on the fact that beaver occupy landscapes in a linear fashion along strips of shoreline rather than exploiting extensive areas. The assumption was that the linear model would provide a more precise and just method of distributing the municipal quota among landowners. Here we test the hypothesis that the length of beaverutilized shoreline is a better predictor of beaver colony density than the area of beaver habitat on 13 beaver management units of typical size (794 – 2200 hectares in Bø Township, Norway, during 2 years. As hypothesized, the number of beaver occupied sites on management units correlated significantly (p≤ 0.001 with the length of beaver-utilized shoreline, but not with the area of beaver habitat. Therefore municipalities should employ the linear model when a precise distribution of quotas is necessary. The density of Eurasian beaver colonies at the landscape scale (>100 km2 in south-central Scandinavia averages approximately 1 occupied site per 4 km2. This figure can be employed by municipal wildlife managers to estimate the colony density in their townships, and to calculate municipal quotas, when more precise census information is lacking.

  8. Impact of the keystone species, the Eurasian beaver (Castor fiber), on habitat structure and its significance to mammals

    OpenAIRE

    Samas, Arūnas

    2016-01-01

    Eurasian beaver (Castor fiber), the representative of the family Castoridae, which includes two living species of the genus Castor. Beavers are the keystone species, also deservedly known as the ecosystem engineer for the ability to create new habitats and to change the existing landscape. Biology of the Eurasian beaver is well studied, but still, there is a lack of knowledge about the ecology of the species - the relationship with the surrounding environment and biota. These studies were car...

  9. Design to monitor trend in abundance and presence of American beaver (Castor canadensis) at the national forest scale.

    Science.gov (United States)

    Beck, Jeffrey L; Dauwalter, Daniel C; Gerow, Kenneth G; Hayward, Gregory D

    2010-05-01

    Wildlife conservationists design monitoring programs to assess population dynamics, project future population states, and evaluate the impacts of management actions on populations. Because agency mandates and conservation laws call for monitoring data to elicit management responses, it is imperative to design programs that match the administrative scale for which management decisions are made. We describe a program to monitor population trends in American beaver (Castor canadensis) on the US Department of Agriculture, Black Hills National Forest (BHNF) in southwestern South Dakota and northeastern Wyoming, USA. Beaver have been designated as a management indicator species on the BHNF because of their association with riparian and aquatic habitats and its status as a keystone species. We designed our program to monitor the density of beaver food caches (abundance) within sampling units with beaver and the proportion of sampling units with beavers present at the scale of a national forest. We designated watersheds as sampling units in a stratified random sampling design that we developed based on habitat modeling results. Habitat modeling indicated that the most suitable beaver habitat was near perennial water, near aspen (Populus tremuloides) and willow (Salix spp.), and in low gradient streams at lower elevations. Results from the initial monitoring period in October 2007 allowed us to assess costs and logistical considerations, validate our habitat model, and conduct power analyses to assess whether our sampling design could detect the level of declines in beaver stated in the monitoring objectives. Beaver food caches were located in 20 of 52 sampled watersheds. Monitoring 20 to 25 watersheds with beaver should provide sufficient power to detect 15-40% declines in the beaver food cache index as well as a twofold decline in the odds of beaver being present in watersheds. Indices of abundance, such as the beaver food cache index, provide a practical measure of

  10. Dams and Intergovernmental Transfers

    Science.gov (United States)

    Bao, X.

    2012-12-01

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

  11. Small dams need better management

    Science.gov (United States)

    Balcerak, Ernie

    2012-03-01

    Many small dams around the world are poorly maintained and represent a safety hazard, according to Pisaniello et al. Better oversight of small dams is needed, the authors argue. The researchers reviewed literature, conducted case studies in four states in Australia, and developed policy benchmarks and best practices for small-dam management. Small dams, often just several meters high and typically privately owned by individual farmers, have historically caused major damage when they fail. For instance, in China in 1975, 230,000 people died when two large dams failed because of the cumulative failure of 60 smaller upstream dams. In the United States, in 1977 the 8-meter-high Kelly Barnes Lake dam failed, killing 39 people. Many other small-dam failures around the world have resulted in casualties and severe ecological and economic damage.

  12. Trends in Rocky Mountain amphibians and the role of beaver as a keystone species

    Science.gov (United States)

    Hossack, Blake R.; Gould, William R.; Patla, Debra A.; Muths, Erin L.; Daley, Rob; Legg, Kristin; Corn, P. Stephen

    2015-01-01

    Despite prevalent awareness of global amphibian declines, there is still little information on trends for many widespread species. To inform land managers of trends on protected landscapes and identify potential conservation strategies, we collected occurrence data for five wetland-breeding amphibian species in four national parks in the U.S. Rocky Mountains during 2002–2011. We used explicit dynamics models to estimate variation in annual occupancy, extinction, and colonization of wetlands according to summer drought and several biophysical characteristics (e.g., wetland size, elevation), including the influence of North American beaver (Castor canadensis). We found more declines in occupancy than increases, especially in Yellowstone and Grand Teton national parks (NP), where three of four species declined since 2002. However, most species in Rocky Mountain NP were too rare to include in our analysis, which likely reflects significant historical declines. Although beaver were uncommon, their creation or modification of wetlands was associated with higher colonization rates for 4 of 5 amphibian species, producing a 34% increase in occupancy in beaver-influenced wetlands compared to wetlands without beaver influence. Also, colonization rates and occupancy of boreal toads (Anaxyrus boreas) and Columbia spotted frogs (Rana luteiventris) were ⩾2 times higher in beaver-influenced wetlands. These strong relationships suggest management for beaver that fosters amphibian recovery could counter declines in some areas. Our data reinforce reports of widespread declines of formerly and currently common species, even in areas assumed to be protected from most forms of human disturbance, and demonstrate the close ecological association between beaver and wetland-dependent species.

  13. Wynoochee Dam Foundation Report

    Science.gov (United States)

    1988-01-01

    schists and in propylitized andesite volcanic rocks. Tests on chlorite-bearing graywackes (Lumni Island and Robe Quarry, Seattle District) and... propylitized chlorite-bearing andesites (Blue River and Lookout Point Dams, Portland District) have shown these rocks to be durable materials with only minor

  14. Gestational hypoxia disrupts the neonatal leptin surge and programs hyperphagia and obesity in male offspring in the Sprague-Dawley rat.

    Science.gov (United States)

    Vargas, Vladimir E; Gurung, Sunam; Grant, Benjamin; Hyatt, Kimberly; Singleton, Krista; Myers, Sarah M; Saunders, Debra; Njoku, Charity; Towner, Rheal; Myers, Dean A

    2017-01-01

    The effect of gestational hypoxia on the neonatal leptin surge, development of hypothalamic arcuate nuclei (ARH) projections and appetite that could contribute to the programming of offspring obesity is lacking. We examined the effect of 12% O2 from gestational days 15-19 in the Sprague-Dawley rat on post-weaning appetite, fat deposition by MRI, adipose tissue cytokine expression, the neonatal leptin surge, ARH response to exogenous leptin, and αMSH projections to the paraventricular nucleus (PVN) in response to a high fat (HFD) or control diet (CD) in male offspring. Normoxia (NMX) and Hypoxia (HPX) offspring exhibited increased food intake when fed a HFD from 5-8 weeks post-birth; HPX offspring on the CD had increased food intake from weeks 5-7 vs. NMX offspring on a CD. HPX offspring on a HFD remained hyperphagic through 23 weeks. Body weight were the same between offspring from HPX vs. NMX dams from 4-12 weeks of age fed a CD or HFD. By 14-23 weeks of age, HPX offspring fed the CD or HFD as well as male NMX offspring fed the HFD were heavier vs. NMX offspring fed the CD. HPX offspring fed a CD exhibited increased abdominal adiposity (MRI) that was amplified by a HFD. HPX offspring fed a HFD exhibited the highest abdominal fat cytokine expression. HPX male offspring had higher plasma leptin from postnatal day (PN) 6 through 14 vs. NMX pups. HPX offspring exhibited increased basal c-Fos labeled cells in the ARH vs. NMX pups on PN16. Leptin increased c-Fos staining in the ARH in NMX but not HPX offspring at PN16. HPX offspring had fewer αMSH fibers in the PVN vs. NMX offspring on PN16. In conclusion, gestational hypoxia impacts the developing ARH resulting in hyperphagia contributing to adult obesity on a control diet and exacerbated by a HFD.

  15. Alterations in offspring behavior induced by chronic prenatal cocaine dosing.

    Science.gov (United States)

    Smith, R F; Mattran, K M; Kurkjian, M F; Kurtz, S L

    1989-01-01

    Sperm-positive female Long-Evans hooded rats were dosed subcutaneously with 10 mg/kg/day cocaine or an equal volume of vehicle (0.9% sterile saline) from gestation day 4 (GD4) through GD18. Offspring were assessed for development of negative geotaxis, righting reflex, spontaneous alternation, and open field activity, and for adult behaviors including DRL-20 acquisition, water maze, visual discrimination, barbiturate sleep time, shuttlebox avoidance, footshock sensitivity, and tail flick latency. Cocaine dosing produced no significant effects on dam weight gain, any measure of litter size and weight, or early postnatal behavioral tests, but there were significant drug effects on development of spontaneous alternation, development of open field activity, DRL-20 acquisition, water maze performance, tail flick, and footshock sensitivity. These data suggest that chronic administration of a modest dose of cocaine during gestation in the rat alters a number of behaviors in the offspring.

  16. Maternal obesity during gestation impairs fatty acid oxidation and mitochondrial SIRT3 expression in rat offspring at weaning.

    Directory of Open Access Journals (Sweden)

    Sarah J Borengasser

    Full Text Available In utero exposure to maternal obesity increases the offspring's risk of obesity in later life. We have also previously reported that offspring of obese rat dams develop hepatic steatosis, mild hyperinsulinemia, and a lipogenic gene signature in the liver at postnatal day (PND21. In the current study, we examined systemic and hepatic adaptations in male Sprague-Dawley offspring from lean and obese dams at PND21. Indirect calorimetry revealed decreases in energy expenditure (p<0.001 and increases in RER values (p<0.001, which were further exacerbated by high fat diet (45% kcals from fat consumption indicating an impaired ability to utilize fatty acids in offspring of obese dams as analyzed by PRCF. Mitochondrial function is known to be associated with fatty acid oxidation (FAO in the liver. Several markers of hepatic mitochondrial function were reduced in offspring of obese dams. These included SIRT3 mRNA (p = 0.012 and mitochondrial protein content (p = 0.002, electron transport chain complexes (II, III, and ATPase, and fasting PGC-1α mRNA expression (p<0.001. Moreover, hepatic LCAD, a SIRT3 target, was not only reduced 2-fold (p<0.001 but was also hyperacetylated in offspring of obese dams (p<0.005 suggesting decreased hepatic FAO. In conclusion, exposure to maternal obesity contributes to early perturbations in whole body and liver energy metabolism. Mitochondrial dysfunction may be an underlying event that reduces hepatic fatty acid oxidation and precedes the development of detrimental obesity associated co-morbidities such as insulin resistance and NAFLD.

  17. Beaver ponds increase methylmercury concentrations in Canadian shield streams along vegetation and pond-age gradients.

    Science.gov (United States)

    Roy, Virginie; Amyot, Marc; Carignan, Richard

    2009-08-01

    Beaver impoundments flood forested areas and may be important production sites for methylmercury (MeHg) because of the resulting enhanced microbial activity and oxygen depletion. The influence of 17 beaver impoundments on streamwater chemistry (total mercury (THg), MeHg, nutrients, cations, and anions)] was investigated by sampling sites located along vegetation and pond-age gradients in southwestern Quebec (Canada). Recently inundated beaver ponds (beaver ponds as suggested by depletions of dissolved oxygen, sulfate and nitrite-nitrate concentrations, and increases in nutrients (e.g., dissolved organic carbon, total phosphorus, and total nitrogen) in outlets compared to inlets. Acidic waters at coniferous sites may have stimulated more MeHg production than in mixed woodland regions. Lower methylation efficiencies in older ponds (> 20 years old) may be due to the degradation of less labile organic matter as ponds age. Beavers actively alter watersheds by building impoundments, and our findings indicate that this landscape disturbance may be a significant source of MeHg to downstream water bodies.

  18. 77 FR 71189 - AES Beaver Valley, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2012-11-29

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER13-442-000] AES Beaver Valley, LLC; Supplemental Notice That Initial Market- Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding, of AES Beaver...

  19. Development of a reliable method for determining sex for a primitive rodent, the Point Arena mountain beaver (Aplodontia rufa nigra)

    Science.gov (United States)

    Kristine L. Pilgrim; William J. Zielinski; Fredrick V. Schlexer; Michael K. Schwartz

    2012-01-01

    The mountain beaver (Aplodontia rufa) is a primitive species of rodent, often considered a living fossil. The Point Arena mountain beaver (Aplodontia rufa nigra) is an endangered subspecies that occurs in a very restricted range in northern California. Efforts to recover this taxon have been limited by the lack of knowledge on their demography, particularly sex and age...

  20. Geology of the central Mineral Mountains, Beaver County, Utah

    Energy Technology Data Exchange (ETDEWEB)

    Sibbett, B.S.; Nielson, D.L.

    1980-03-01

    The Mineral Mountains are located in Beaver and Millard Counties, southwestern Utah. The range is a horst located in the transition zone between the Basin and Range and Colorado Plateau geologic provinces. A multiple-phase Tertiary pluton forms most of the range, with Paleozoic rocks exposed on the north and south and Precambrian metamorphic rocks on the west in the Roosevelt Hot Springs KGRA (Known Geothermal Resource Area). Precambrian banded gneiss and Cambrian carbonate rocks have been intruded by foliated granodioritic to monzonitic rocks of uncertain age. The Tertiary pluton consists of six major phases of quartz monzonitic to leucocratic granitic rocks, two diorite stocks, and several more mafic units that form dikes. During uplift of the mountain block, overlying rocks and the upper part of the pluton were partially removed by denudation faulting to the west. The interplay of these low-angle faults and younger northerly trending Basin and Range faults is responsible for the structural control of the Roosevelt Hot Springs geothermal system. The structural complexity of the Roosevelt Hot Springs KGRA is unique within the range, although the same tectonic style continues throughout the range. During the Quaternary, rhyolite volcanism was active in the central part of the range and basaltic volcanism occurred in the northern portion of the map area. The heat source for the geothermal system is probably related to the Quaternary rhyolite volcanic activity.

  1. Characterization of the North American beaver (Castor canadensis) papillomavirus genome.

    Science.gov (United States)

    Rogovskyy, Artem S; Chen, Zigui; Burk, Robert D; Bankhead, Troy

    2014-01-10

    The papillomaviruses comprise a large group of viruses that cause proliferations of the stratified squamous epithelium of skin and mucosa in a variety of animals. An earlier report identified a novel papillomavirus of the North American beaver, Castor canadensis (CcanPV1) that was associated with cutaneous exophytic lesions. In the current study, we determined the sequence of the complete 7435 basepair genome of CcanPV1. The genome contains an Upstream Regulatory Region located between the end of L1 and the start of E6, and seven canonical papillomavirus open reading frames encoding five early (E6, E7, E1, E2, and E4) and two late (L2 and L1) proteins. No E5 open reading frame was detected. Phylogenetic analysis of the CcanPV1 genome places the virus between the genera Kappapapillomavirus and Mupapillomavirus. Analyses of the papillomavirus genomes detected in different species of the order Rodentia indicate these viruses do not form a monophyletic clade. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Effects of ewe size and nutrition on fetal mammary gland development and lactational performance of offspring at their first lactation.

    Science.gov (United States)

    van der Linden, D S; Kenyon, P R; Blair, H T; Lopez-Villalobos, N; Jenkinson, C M C; Peterson, S W; Mackenzie, D D S

    2009-12-01

    Many environmental factors applied postnatally are known to affect milk production of the dam, but to date, the effects of different fetal environments on subsequent first lactational performance of the offspring have not been reported. Four hundred fifty heavy (H; 60.8 kg +/- 0.18) and 450 light (L; 42.5 kg +/- 0.17) dams were randomly allocated to ad libitum (A) or maintenance (M) nutritional regimens from d 21 until d 140 of pregnancy, under pastoral grazing conditions (HA, n = 151; HM, n = 153; LA, n = 155; LM, n = 153). At d 100 of pregnancy, a sub-group of twin-bearing dams was killed and fetal mammary glands collected. From 1 wk before lambing, all remaining dams were fed ad libitum until weaning. After weaning, female progeny were managed and fed under pastoral conditions as 1 group. At 2 yr of age, 72 twin-rearing ewe offspring were milked once a week for 7 wk. Fetuses from M-dams had heavier mammary glands (P = 0.03) compared with A-fetuses. Fetuses from H-dams had greater (P = 0.0008) mammary duct area compared with L-fetuses. At 2 yr of age, M-offspring had greater milk yields at d 7 (P = 0.02) and d 28 (P = 0.09) of lactation and tended to have greater accumulated milk yields (P = 0.11) compared with A-offspring. Ewes born to M-dams showed greater lactose percentage at d 14 (P = 0.002), d 21 (P = 0.06), and d 28 (P = 0.07) of lactation and greater (P = 0.049) accumulated lactose yields and CP (P = 0.06) yields compared with A-offspring. Ewes born to H-dams displayed greater milk yields at d 14 (P = 0.08) and d 21 (P = 0.02) and had greater accumulated milk yield (P = 0.08) and lactose yield (P = 0.04) compared with L-offspring. Lambs born to M-offspring were heavier at birth (P = 0.02) and grew faster until weaning (P = 0.02), matching the milk yield and composition data, compared with their ad libitum counterparts. Birth weight was not affected (P > 0.10) by grand dam size; however, lambs born to H-offspring grew faster from birth until d 49 of age (P

  3. Assessment of a new Bacteroidales marker targeting North American beaver (Castor canadensis) fecal pollution by real-time PCR.

    Science.gov (United States)

    Marti, Romain; Zhang, Yun; Tien, Yuan-Ching; Lapen, David R; Topp, Edward

    2013-11-01

    In many settings wildlife can be a significant source of fecal pathogen input into surface water. The North American beaver (Castor canadensis) is a zoonotic reservoir for several human pathogens including Cryptosporidium spp. and Giardia spp. In order to specifically detect fecal pollution by beavers, we have developed and validated a beaver-specific Bacteroidales marker, designated Beapol01, based on the 16S rRNA gene. The marker is suitable for quantifying pollution using real-time PCR. The specificity and sensitivity of the marker was excellent, Beaver signal was detected in water of a mixed-activity watershed harbouring this rodent. Overall, Beapol01 will be useful for a better understanding of fecal source inputs in drainage basins inhabited by the beaver. © 2013.

  4. Expansion at Olympic Dam

    International Nuclear Information System (INIS)

    Lewis, C.

    1997-01-01

    The Olympic Dam orebody is the 6th largest copper and the single largest uranium orebody in the world. Mine production commenced in June 1988, at an annual production rate of around 45,000 tonnes of copper and 1,000 tonnes of uranium. Western Mining Corporation announced in 1996 a proposed $1.25 billion expansion of the Olympic Dam operation to raise the annual production capacity of the mine to 200,000 tonnes of copper, approximately 3,700 tonnes of uranium, 75,000 ounces of gold and 950,000 ounces of silver by 2001. Further optimisation work has identified a faster track expansion route, with an increase in the capital cost to $1.487 billion but improved investment outcome, a new target completion date of end 1999, and a new uranium output of 4,600 tonnes per annum from that date

  5. High fat diet and in utero exposure to maternal obesity disrupts circadian rhythm and leads to metabolic programming of liver in rat offspring.

    Directory of Open Access Journals (Sweden)

    Sarah J Borengasser

    Full Text Available The risk of obesity in adulthood is subject to programming beginning at conception. In animal models, exposure to maternal obesity and high fat diets influences the risk of obesity in the offspring. Among other long-term changes, offspring from obese rats develop hyperinsulinemia, hepatic steatosis, and lipogenic gene expression in the liver at weaning. However, the precise underlying mechanisms leading to metabolic dysregulation in the offspring remains unclear. Using a rat model of overfeeding-induced obesity, we previously demonstrated that exposure to maternal obesity from pre-conception to birth, is sufficient to program increased obesity risk in the offspring. Offspring of obese rat dams gain greater body weight and fat mass when fed high fat diet (HFD as compared to lean dam. Since, disruptions of diurnal circadian rhythm are known to detrimentally impact metabolically active tissues such as liver, we examined the hypothesis that maternal obesity leads to perturbations of core clock components and thus energy metabolism in offspring liver. Offspring from lean and obese dams were examined at post-natal day 35, following a short (2 wk HFD challenge. Hepatic mRNA expression of circadian (CLOCK, BMAL1, REV-ERBα, CRY, PER and metabolic (PPARα, SIRT1 genes were strongly suppressed in offspring exposed to both maternal obesity and HFD. Using a mathematical model, we identified two distinct biological mechanisms that modulate PPARα mRNA expression: i decreased mRNA synthesis rates; and ii increased non-specific mRNA degradation rate. Moreover, our findings demonstrate that changes in PPARα transcription were associated with epigenomic alterations in H3K4me3 and H3K27me3 histone marks near the PPARα transcription start site. Our findings indicated that offspring from obese rat dams have detrimental alternations to circadian machinery that may contribute to impaired liver metabolism in response to HFD, specifically via reduced PPAR

  6. Impact of maternal mild hyperglycemia on maternal care and offspring development and behavior of Wistar rats.

    Science.gov (United States)

    Kiss, Ana Carolina Inhasz; Woodside, Barbara; Felício, Luciano Freitas; Anselmo-Franci, Janete; Damasceno, Débora Cristina

    2012-10-10

    The aim of the present study was to evaluate the effect of maternal mild hyperglycemia on maternal behavior, as well as the development, behavior, reproductive function, and glucose tolerance of the offspring. At birth, litters were assigned either to Control (subcutaneous (sc)-citrate buffer) or STZ groups (streptozotocin (STZ)-100mg/kg-sc.). On PND 90 both STZ-treated and Control female rats were mated. Glucose tolerance tests (GTT) and insulin tolerance tests (ITT) were performed during pregnancy. Pregnancy duration, litter size and sex ratio were assessed. Newborns were classified according to birth weight as small (SPA), adequate (APA), or large for pregnancy age (LPA). Maternal behavior was analyzed on PND 5 and 10. Offspring body weight, length, and anogenital distance were measured and general activity was assessed in the open field. Sexual behavior was tested in both male and female offspring. Levels of reproductive hormones and estrous cycle duration were evaluated in female offspring. Female offspring were mated and both a GTT and ITT performed during pregnancy. Neonatal STZ administration caused mild hyperglycemia during pregnancy and changed some aspects of maternal care. The hyperglycemic intrauterine milieu impaired physical development and increased immobility in the open field in the offspring although the latter effect appeared at different ages for males (adulthood) and females (infancy). There was no impairment in the sexual behavior of either male or female offspring. As adults, female offspring of STZ-treated mothers did not show glucose intolerance during pregnancy. Thus, offspring of female rats that show mild hyperglycemia in pregnancy have fewer behavioral and developmental impairments than previously reported in the offspring of severely diabetic dams suggesting that the degree of impairment is directly related to the mother glycemic intensity. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. The hydrological modeling in terms of determining the potential European beaver effect

    Directory of Open Access Journals (Sweden)

    Szostak Marta

    2017-06-01

    Full Text Available The objective of the paper was the hydrological analysis, in terms of categorizing main watercourses (based on coupled catchments and marking areas covered by potential impact of the occurrence and activities of the European beaver Castor fiber. At the analysed area – the Forest District Głogów Małopolski there is a population of about 200 beavers in that Forest District. Damage inflicted by beavers was detected on 33.0 ha of the Forest District, while in the area of 13.9 ha the damage was small (below 10%. The monitoring of the beavers’ behaviour and the analysis of their influence on hydrology of the area became an important element of using geoinformationtools in the management of forest areas.

  8. Beaver Valley Power Station and Shippingport Atomic Power Station. 1984 Annual environmental report, radiological. Volume 2

    International Nuclear Information System (INIS)

    1985-01-01

    This report describes the Radiological Environmental Monitoring Program conducted during 1984 in the vicinity of the Beaver Valley Power Station and the Shippingport Atomic Power Station. The Radiological Environmental Program consists of on-site sampling of water and gaseous effluents and off-site monitoring of water, air, river sediments, soils, food pathway samples, and radiation levels in the vicinity of the site. This report discusses the results of this monitoring during 1984. The environmental program outlined in the Beaver Valley Power Station Technical Specifications was followed throughout 1984. The results of this environmental monitoring program show that Shippingport Atomic Power Station and Beaver Valley Power Station operations have not adversely affected the surrounding environment. 23 figs., 18 tabs

  9. The impaired myocardial ischemic tolerance in adult offspring of diabetic pregnancy is restored by maternal melatonin treatment.

    Science.gov (United States)

    Gao, Ling; Zhao, Yi-Chao; Liang, Yan; Lin, Xian-Hua; Tan, Ya-Jing; Wu, Dan-Dan; Li, Xin-Zhu; Ye, Bo-Zhi; Kong, Fan-Qi; Sheng, Jian-Zhong; Huang, He-Feng

    2016-10-01

    Diabetic pregnancy, with ever increasing prevalence, adversely affects embryogenesis and increases vasculometabolic disorder risks in adult offspring. However, it remains poorly understood whether maternal diabetes increases the offspring's susceptibility to heart injuries in adulthood. In this study, we observed that cardiac function and structure were comparable between adult offspring born to diabetic mice and their counterparts born to nondiabetic mice at baseline. However, in response to myocardial ischemia/reperfusion (MIR), diabetic mother offspring exhibited augmented infarct size, cardiac dysfunction, and myocardial apoptosis compared with control, in association with exaggerated activation of mitochondria- and endoplasmic reticulum (ER) stress-mediated apoptosis pathways and oxidative stress. Molecular analysis showed that the impaired myocardial ischemic tolerance in diabetic mother offspring was mainly attributable to blunted cardiac insulin receptor substrate (IRS)-1/Akt signaling. Furthermore, the effect of maternal melatonin administration on offspring's response to MIR was determined, and the results indicated that melatonin treatment in diabetic dams during pregnancy significantly improved the tolerance to MIR injury in their offspring, via restoring cardiac IRS-1/Akt signaling. Taken together, these data suggest that maternal diabetes predisposes offspring to augmented MIR injury in adulthood, and maternal melatonin supplementation during diabetic pregnancy may hold promise for improving myocardial ischemic tolerance in the offspring. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Dam spills and fishes

    International Nuclear Information System (INIS)

    1996-01-01

    This short paper reports the main topics discussed during the two days of the annual colloquium of the Hydro-ecology Committee of EdF. The first day was devoted to the presentation of the joint works carried out by EdF, the Paul-Sabatier University (Toulouse), the Provence St-Charles University (Marseille), the ENSAT (Toulouse) and the CEMAGREF (Lyon and Aix-en-Provence) about the environmental impact of dam spills on the aquatic flora and fauna downstream. A synthesis and recommendations were presented for the selection and characterization of future sites. The second day was devoted to the hydro-ecology study of the dam reservoir of Petit-Saut (French Guyana): water reoxygenation, quality evolution, organic matter, plankton, invertebrates and fishes. The 134 French dams concerned by water spills have been classified according to the frequency of spills, the variations of flow rates created, and their impacts on fishing, walking, irrigation, industry, drinking water, navigation, bathing. Particular studies on different sites have demonstrated the complexity of the phenomena involved concerning the impact on the ecosystems and the water quality. (J.S.)

  11. Maternal obesity during gestation impairs fatty acid oxidation and mitochondrial SIRT3 expression in rat offspring at weaning

    Science.gov (United States)

    In utero exposure to maternal obesity increases the offspring’s risk of obesity in later life. We have also previously reported that offspring of obese rat dams develop hepatic steatosis, mild hyperinsulinemia, and a lipogenic gene signature in the liver at postnatal day (PND) 21. In the current s...

  12. Bacterial and Archaeal Diversity in the Gastrointestinal Tract of the North American Beaver (Castor canadensis.

    Directory of Open Access Journals (Sweden)

    Robert J Gruninger

    Full Text Available The North American Beaver (Castor canadensis is the second largest living rodent and an iconic symbol of Canada. The beaver is a semi-aquatic browser whose diet consists of lignocellulose from a variety of plants. The beaver is a hindgut fermenter and has an enlarged ceacum that houses a complex microbiome. There have been few studies examining the microbial diversity in gastrointestinal tract of hindgut fermenting herbivores. To examine the bacterial and archaeal communities inhabiting the gastrointestinal tract of the beaver, the microbiome of the ceacum and feaces was examined using culture-independent methods. DNA from the microbial community of the ceacum and feaces of 4 adult beavers was extracted, and the16S rRNA gene was sequenced using either bacterial or archaeal specific primers. A total of 1447 and 1435 unique bacterial OTUs were sequenced from the ceacum and feaces, respectively. On average, the majority of OTUs within the ceacum were classified as Bacteroidetes (49.2% and Firmicutes (47.6%. The feaces was also dominated by OTUs from Bacteroidetes (36.8% and Firmicutes (58.9%. The composition of bacterial community was not significantly different among animals. The composition of the ceacal and feacal microbiome differed, but this difference is due to changes in the abundance of closely related OTUs, not because of major differences in the taxonomic composition of the communities. Within these communities, known degraders of lignocellulose were identified. In contrast, to the bacterial microbiome, the archaeal community was dominated by a single species of methanogen, Methanosphaera stadtmanae. The data presented here provide the first insight into the microbial community within the hindgut of the beaver.

  13. Bacterial and Archaeal Diversity in the Gastrointestinal Tract of the North American Beaver (Castor canadensis).

    Science.gov (United States)

    Gruninger, Robert J; McAllister, Tim A; Forster, Robert J

    2016-01-01

    The North American Beaver (Castor canadensis) is the second largest living rodent and an iconic symbol of Canada. The beaver is a semi-aquatic browser whose diet consists of lignocellulose from a variety of plants. The beaver is a hindgut fermenter and has an enlarged ceacum that houses a complex microbiome. There have been few studies examining the microbial diversity in gastrointestinal tract of hindgut fermenting herbivores. To examine the bacterial and archaeal communities inhabiting the gastrointestinal tract of the beaver, the microbiome of the ceacum and feaces was examined using culture-independent methods. DNA from the microbial community of the ceacum and feaces of 4 adult beavers was extracted, and the16S rRNA gene was sequenced using either bacterial or archaeal specific primers. A total of 1447 and 1435 unique bacterial OTUs were sequenced from the ceacum and feaces, respectively. On average, the majority of OTUs within the ceacum were classified as Bacteroidetes (49.2%) and Firmicutes (47.6%). The feaces was also dominated by OTUs from Bacteroidetes (36.8%) and Firmicutes (58.9%). The composition of bacterial community was not significantly different among animals. The composition of the ceacal and feacal microbiome differed, but this difference is due to changes in the abundance of closely related OTUs, not because of major differences in the taxonomic composition of the communities. Within these communities, known degraders of lignocellulose were identified. In contrast, to the bacterial microbiome, the archaeal community was dominated by a single species of methanogen, Methanosphaera stadtmanae. The data presented here provide the first insight into the microbial community within the hindgut of the beaver.

  14. Beaver-mediated lateral hydrologic connectivity, fluvial carbon and nutrient flux, and aquatic ecosystem metabolism

    Science.gov (United States)

    Wegener, Pam; Covino, Tim; Wohl, Ellen

    2017-06-01

    River networks that drain mountain landscapes alternate between narrow and wide valley segments. Within the wide segments, beaver activity can facilitate the development and maintenance of complex, multithread planform. Because the narrow segments have limited ability to retain water, carbon, and nutrients, the wide, multithread segments are likely important locations of retention. We evaluated hydrologic dynamics, nutrient flux, and aquatic ecosystem metabolism along two adjacent segments of a river network in the Rocky Mountains, Colorado: (1) a wide, multithread segment with beaver activity; and, (2) an adjacent (directly upstream) narrow, single-thread segment without beaver activity. We used a mass balance approach to determine the water, carbon, and nutrient source-sink behavior of each river segment across a range of flows. While the single-thread segment was consistently a source of water, carbon, and nitrogen, the beaver impacted multithread segment exhibited variable source-sink dynamics as a function of flow. Specifically, the multithread segment was a sink for water, carbon, and nutrients during high flows, and subsequently became a source as flows decreased. Shifts in river-floodplain hydrologic connectivity across flows related to higher and more variable aquatic ecosystem metabolism rates along the multithread relative to the single-thread segment. Our data suggest that beaver activity in wide valleys can create a physically complex hydrologic environment that can enhance hydrologic and biogeochemical buffering, and promote high rates of aquatic ecosystem metabolism. Given the widespread removal of beaver, determining the cumulative effects of these changes is a critical next step in restoring function in altered river networks.

  15. In-situ reconstruction of the MSRs at the Beaver Valley Nuclear Power Station

    International Nuclear Information System (INIS)

    Deahna, S.T.; Yarden, A.L.; Tam, C.W.

    1992-01-01

    Moisture Separator Reheaters (MSRs) have been problem components at Beaver Valley Unit 1 since the initial plant start-up in 1976. Their performance had been ineffective and reheater tube reliability was becoming a limiting factor in MSR operation. Many of the problems encountered were common to the nuclear industry. In 1991, Duquesne Light performed a major overhaul of the Beaver Valley Unit 1 MSRs in an attempt to restore them to an acceptable level of performance. This paper summarizes the operating history, engineering redesign, field reconstruction, and subsequent performance of these MSRs

  16. BOREAS TGB-5 Dissolved Organic Carbon Data from NSA Beaver Ponds

    Science.gov (United States)

    Bourbonniere, Rick; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Trace Gas Biogeochemistry (BOREAS TGB-5) team collected several data sets related to carbon and trace gas fluxes and concentrations in the Northern Study Area (NSA). This data set contains concentrations of dissolved organic and inorganic carbon species from water samples collected at various NSA sites. In particular, this set covers the NSA Tower Beaver Pond Site and the NSA Gillam Road Beaver Pond Site, including data from all visits to open water sampling locations during the BOREAS field campaigns from April to September 1994. The data are provided in tabular ASCII files.

  17. Odelouca Dam Construction: Numerical Analysis

    OpenAIRE

    Brito, A.; Maranha, J. R.; Caldeira, L.

    2012-01-01

    Odelouca dam is an embankment dam, with 76 m height, recently constructed in the south of Portugal. It is zoned with a core consisting of colluvial and residual schist soil and with soil-rockfill mixtures making up the shells (weathered schist with a significant fraction of coarse sized particles). This paper presents a numerical analysis of Odelouca Dam`s construction. The material con-stants of the soil model used are determined from a comprehensive testing programme carried out in the C...

  18. Health impacts of large dams

    International Nuclear Information System (INIS)

    Lerer, L.B.

    1999-01-01

    Large dams have been criticized because of their negative environmental and social impacts. Public health interest largely has focused on vector-borne diseases, such as schistosomiasis, associated with reservoirs and irrigation projects. Large dams also influence health through changes in water and food security, increases in communicable diseases, and the social disruption caused by construction and involuntary resettlement. Communities living in close proximity to large dams often do not benefit from water transfer and electricity generation revenues. A comprehensive health component is required in environmental and social impact assessments for large dam projects

  19. Effects of chronic social stress and maternal intranasal oxytocin and vasopressin on offspring interferon γ and behavior

    Directory of Open Access Journals (Sweden)

    Chris Anthony Murgatroyd

    2016-12-01

    Full Text Available Recent studies support the hypothesis that the adverse effects of early life adversity and transgenerational stress on neural plasticity and behavior are mediated by inflammation. The objective of the present study was to investigate the immune and behavioural programming effects of intranasal (IN vasopressin (AVP and oxytocin (OXT treatment of chronic social stress (CSS exposed F1 dams on F2 juvenile female offspring. It was hypothesized that maternal AVP and OXT treatment would have preventative effects on social stress induced deficits in offspring anxiety and social behavior, and that these effects would be associated with changes in interferon γ (IFNγ. Control and CSS exposed F1 dams were administered IN saline, AVP, or OXT during lactation and the F2 juvenile female offspring were assessed for basal plasma IFNγ and perseverative, anxiety, and social behavior. CSS F2 female juvenile offspring had elevated IFNγ levels and exhibited increased repetitive/perseverative and anxiety behaviours and deficits in social behavior. These effects were modulated by AVP and OXT in a context and behavior dependent manner, with OXT exhibiting preventative effects on repetitive and anxiety behaviours and AVP possessing preventative effects on social behavior deficits and anxiety. Basal IFNγ levels were elevated in the F2 offspring of OXT treated F1 dams, but IFNγ was not correlated with the behavioural effects. These results support the hypothesis that maternal AVP and OXT treatment have context and behavior specific effects on peripheral IFNγ levels and perseverative, anxiety, and social behaviours in the female offspring of early life social stress exposed dams. Both maternal AVP and OXT are effective at preventing social stress induced increases in self-directed measures of anxiety, and AVP is particularly effective at preventing impairments in overall social contact. Oxytocin is specifically effective at preventing repetitive

  20. Maternal Phytosterol Supplementation during Pregnancy and Lactation Modulates Lipid and Lipoprotein Response in Offspring of apoE-Deficient Mice.

    Science.gov (United States)

    Rideout, Todd C; Movsesian, Cheryl; Tsai, Yi-Ting; Iqbal, Aadil; Raslawsky, Amy; Patel, Mulchand S

    2015-08-01

    In utero exposure to excessive cholesterol has been shown to increase fetal plasma cholesterol concentration and predispose adult offspring to cardiovascular disease (CVD) risk. Because lipid-lowering drugs are contraindicated during pregnancy, natural cholesterol-lowering compounds may be a safe and effective alternative to reduce CVD risk in offspring born to hypercholesterolemic mothers. This study used the hypercholesterolemic apolipoprotein E-deficient (apoE(-/-)) mouse model to test the hypothesis that mothers supplemented with phytosterols during gestation and lactation would produce offspring with a more favorable lipid profile than offspring from unsupplemented mothers, despite having a genetic predisposition toward hypercholesterolemia. Sixteen female apoE(-/-) mice were randomly assigned to 2 diets fed throughout the gestation and lactation periods: a cholesterol-enriched diet (CH) (0.15%) or the cholesterol-enriched diet supplemented with phytosterols (CH/PS) (2%). Serum lipids and lipoproteins were measured by enzyme assay and nuclear magnetic resonance spectroscopy, respectively, and liver cholesterol was analyzed by GC. Compared with the CH-fed dams at the end of lactation, phytosterol-supplemented dams displayed lower (P 0.05) in HDL cholesterol and triacylglycerol (TG) concentrations. Pups from phytosterol-fed dams demonstrated lower (P 0.05) in HDL cholesterol compared with pups from CH-fed dams. Furthermore, compared with pups from CH-fed dams, pups from phytosterol-supplemented dams displayed a lower (P phytosterols during gestation and lactation exhibit favorable liver and serum lipid responses compared with pups from unsupplemented mothers. © 2015 American Society for Nutrition.

  1. Dam Break Analysis of Embankment Dams Considering Breach Characteristics

    Directory of Open Access Journals (Sweden)

    Abolfazl Shamsaei

    2004-05-01

    Full Text Available The study of dam's break, needs the definition of various parameters such as the break cause, its type, its dimension and the duration of breach development. The precise forecast for different aspects of the breach is one of the most important factors for analyzing it in embankment dam. The characteristics of the breach and determination of their vulnerability has the most effect on the waves resulting from dam break. Investigating, about the parameters of the breach in "Silveh" earth dam have been determined using the suitable model. In Silve dam a trapezoid breach with side slope z=0.01m and the average base line b=80m was computed. The duration of the breaches development is 1.9 hour. Regarding the above results and the application of DAM Break software the consequences of the probable break of the dam was determined. The analysis of the results of water covering of the city of Piranshahr located 12km from silve dam confirms that in 3 hours the water will reach the height (level of 1425 meters.

  2. Preconception Prebiotic and Sitagliptin Treatment in Obese Rats Affects Pregnancy Outcomes and Offspring Microbiota, Adiposity, and Glycemia

    Directory of Open Access Journals (Sweden)

    Carol A. Dennison

    2017-10-01

    Full Text Available Maternal obesity is associated with increased risk of pregnancy complications and greater risk of obesity in offspring, but studies designed to examine preconception weight loss are limited. The objective of this study was to determine if a combined dietary [oligofructose (OFS] and pharmacological (sitagliptin preconception intervention could mitigate poor pregnancy outcomes associated with maternal obesity and improve offspring metabolic health and gut microbiota composition. Diet-induced obese female Sprague-Dawley rats were randomized to one of four intervention groups for 8 weeks: (1 Obese-Control (consumed control diet during intervention; (2 Obese-OFS (10% OFS diet; (3 Obese-S (sitagliptin drug; (4 Obese-OFS + S (combination treatment. Two reference groups were also included: (5 Obese-HFS (untreated obese consumed high fat/sucrose diet throughout study; (6 Lean-Control (lean reference group that were never obese and consumed control diet throughout. Offspring consumed control diet until 11 weeks of age followed by HFS diet until 17 weeks of age. The Obese-OFS + S rats lost weight during the intervention phase whereas the OFS and S treatments attenuated weight gain compared with Obese-HFS (p < 0.05. Gestational weight gain was lowest in Obese-OFS + S rats and highest in Obese-HFS rats (p < 0.05. Prepregnancy intervention did not affect reproductive parameters but did affect pregnancy outcomes including litter size. Male Obese-OFS offspring had significantly lower percent body fat than Obese-HFS at 17 weeks. Female Obese-S and Obese-OFS offspring had significantly lower fasting glucose at 17 weeks compared with Obese-Control and Obese-HFS. Clostridium cluster XI was higher in Obese-HFS and Obese-S dams at birth compared with all other groups. Dams with an adverse pregnancy outcome had significantly lower (p = 0.035 Lactobacillus spp. compared with dams with normal or small litters. At weaning, male offspring

  3. Maternal androgen excess and obesity induce sexually dimorphic anxiety-like behavior in the offspring.

    Science.gov (United States)

    Manti, Maria; Fornes, Romina; Qi, Xiaojuan; Folmerz, Elin; Lindén Hirschberg, Angelica; de Castro Barbosa, Thais; Maliqueo, Manuel; Benrick, Anna; Stener-Victorin, Elisabet

    2018-03-22

    Maternal polycystic ovary syndrome (PCOS), a condition associated with hyperandrogenism, is suggested to increase anxiety-like behavior in the offspring. Because PCOS is closely linked to obesity, we investigated the impact of an adverse hormonal or metabolic maternal environment and offspring obesity on anxiety in the offspring. The obese PCOS phenotype was induced by chronic high-fat-high-sucrose (HFHS) consumption together with prenatal dihydrotestosterone exposure in mouse dams. Anxiety-like behavior was assessed in adult offspring with the elevated-plus maze and open-field tests. The influence of maternal androgens and maternal and offspring diet on genes implicated in anxiety were analyzed in the amygdala and hypothalamus with real-time PCR ( n = 47). Independent of diet, female offspring exposed to maternal androgens were more anxious and displayed up-regulation of adrenoceptor α 1B in the amygdala and up-regulation of hypothalamic corticotropin-releasing hormone ( Crh). By contrast, male offspring exposed to a HFHS maternal diet had increased anxiety-like behavior and showed up-regulation of epigenetic markers in the amygdala and up-regulation of hypothalamic Crh. Overall, there were substantial sex differences in gene expression in the brain. These findings provide novel insight into how maternal androgens and obesity exert sex-specific effects on behavior and gene expression in the offspring of a PCOS mouse model.-Manti, M., Fornes, R., Qi, X., Folmerz, E., Lindén Hirschberg, A., de Castro Barbosa, T., Maliqueo, M., Benrick, A., Stener-Victorin, E. Maternal androgen excess and obesity induce sexually dimorphic anxiety-like behavior in the offspring.

  4. A Feasibility Study for Consolidating and/or Coordinating Technical Procedures in Beaver County Pennsylvania Libraries.

    Science.gov (United States)

    Fry, James W.

    In 1977 the Public Library Commission, in conjunction with the State Library of Pennsylvania, received a Library Services and Construction Act, Title III Grant to conduct a feasibility study of technical service operations in various types of libraries within Beaver County. Its objectives were to: (1) analyze existing library materials purchasing…

  5. Hydrogeochemical and stream sediment reconnaissance basic data for Beaver Quadrangle, Alaska

    International Nuclear Information System (INIS)

    1981-01-01

    Field and laboratory data are presented for 642 water samples from the Beaver Quadrangle, Alaska. The samples were collected by Los Alamos Scientific Laboratory; laboratory analysis and data reporting were done by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee

  6. Tom Beaver, Creek Television Reporter. With Teacher's Guide. Native Americans of the Twentieth Century.

    Science.gov (United States)

    Minneapolis Public Schools, MN.

    A biography for elementary school students presents an account of an American Indian television reporter, Tom Beaver (Creek), and includes a map of Oklahoma showing the location of Indian tribes. A teacher's guide following the biography contains information about the Creek tribe and the history of television, learning objectives and directions…

  7. Reproductive characteristics of the Point Arena mountain beaver (Aplodontia rufa nigra)

    Science.gov (United States)

    William Zielinski; M. J. Mazurek

    2016-01-01

    Little is known about the ecology and life history of the federally endangered Point Arena mountain beaver (Aplodontia rufa nigra). The distribution of this primitive burrowing rodent is disjunct from the balance of the species’ range and occurs in a unique maritime environment of coastal grasslands and forests. Fundamental to protecting this taxon...

  8. Establishment of a health surveillance program for reintroduction of the Eurasian beaver (Castor fiber) into Scotland.

    Science.gov (United States)

    Goodman, Gidona; Girling, Simon; Pizzi, Romain; Meredith, Anna; Rosell, Frank; Campbell-Palmer, Roisin

    2012-10-01

    In 2009 and 2010 16 Norwegian Eurasian beavers (Castor fiber) were reintroduced to Knapdale, Scotland as part of a 5-yr reintroduction trial (Scottish Beaver Trial). Despite numerous reintroduction programs throughout Europe there is no published information concerning recommended health surveillance during beaver reintroduction and only one publication describing causes of mortality. We describe the establishment of a health surveillance program based on International Union of Conservation of Nature (IUCN) and governmental guidelines, and report preliminary results based on the fecal and blood samples following the completion of the first stage of reintroduction. Animals underwent at least one general anesthetic to allow collection of fecal and blood samples and a thorough clinical examination. No bacterial enteric pathogens such as Salmonella spp., Campylobacter spp., or Yersinia pseudotuberculosis were isolated, nor were Giardia spp. or Cryptosporidium spp. However, numerous helminths including Travassosius rufus and Stichorchis subtriquetrus were detected. Five animals were positive for Leptospira antibodies. This included Leptospira saxkoebing, Leptospira canicola, Leptospira copenhageni, Leptospira icterohaemorrhagiae, Leptospira autumnalis, and Leptospira javanica. The highest loss of animals (20%) was during the statutory 6-mo rabies quarantine period. No common cause of death was determined. The rabies quarantine conditions were waived for four remaining animals, three of which were introduced to the wild successfully. The authors recommend the shortest possible quarantine period when introducing beavers, but allowing for the minimum recommended IUCN 35 days to allow for implementation of the initial stage of the health surveillance program, examination of animals, sample collection, and processing.

  9. Recycling at Penn State's Beaver Stadium. "Recycle on the Go" Success Story

    Science.gov (United States)

    US Environmental Protection Agency, 2009

    2009-01-01

    With a 13-year-old recycling program, The Pennsylvania State University's (Penn State) Beaver Stadium in the past diverted nearly 30 tons of recyclables per year from local landfills. A new initiative to promote recycling in the stadium's tailgating area has helped Penn State more than triple its old recycling record, collecting 112 tons in 2008.…

  10. Long-Term Hydrological Reconstruction From a Beaver Meadow Using Testate Amoebae

    Science.gov (United States)

    Von Ness, K.; Loisel, J.; Karran, D. J.; Westbrook, C.; Kohlmeyer, C.

    2016-12-01

    Beaver ponds contribute up to 0.8 Tg/yr of atmospheric methane (CH4) globally (Whitfield et al., 2014) and were found to be the largest CH4 emitters among all the wetland types in boreal environments (Roulet et al., 1992). However, the sources and underlying mechanisms of carbon emission and sequestration in beaver ponds requires further elucidation. Here we present the historical development of a beaver meadow located in the Sibbald Research Wetland in the Rocky Mountains of Kananaskis Provincial Park, Alberta, Canada. We use a combination of testate amoebae, plant macrofossils, and other geochemical proxies to provide high-resolution reconstructions along three peat cores extracted in hydrologically distinct portions of the meadow. To our knowledge, this is the first attempt at reconstructing long-term hydrological conditions in these systems. Testate amoebae (Protozoa: Rhizopoda) are single-celled organisms that inhabit moist substrates and produce a decay-resistant test. As each taxon generally occupies a discrete ecological niche related to soil moisture and pH, testate amoebae are good indicators of past and ongoing hydrological change. Preliminary analysis of testate amoebae assemblages downcore suggests that this proxy is suitable to reconstruct hydrological changes in meadows, with wetter and drier communities being in good agreement with wetter and drier plant macrofossil assemblages. The nitrogen isotopic signature of peat samples (ongoing) will be used as a proxy for changes in nutrient input; it could become a proxy for past beaver activity.

  11. A linear programming model of diet choice of free-living beavers

    NARCIS (Netherlands)

    Nolet, BA; VanderVeer, PJ; Evers, EGJ; Ottenheim, MM

    1995-01-01

    Linear programming has been remarkably successful in predicting the diet choice of generalist herbivores. We used this technique to test the diet choice of free-living beavers (Castor fiber) in the Biesbosch (The Netherlands) under different Foraging goals, i.e. maximization of intake of energy,

  12. Selection of Breeding Stock among Australian Purebred Dog Breeders, with Particular Emphasis on the Dam

    Directory of Open Access Journals (Sweden)

    Veronika Czerwinski

    2016-11-01

    Full Text Available Every year, thousands of purebred domestic dogs are bred by registered dog breeders. Yet, little is known about the rearing environment of these dogs, or the attitudes and priorities surrounding breeding practices of these dog breeders. The objective of this study was to explore some of the factors that dog breeders consider important for stock selection, with a particular emphasis on issues relating to the dam. Two-hundred and seventy-four Australian purebred dog breeders, covering 91 breeds across all Australian National Kennel Club breed groups, completed an online survey relating to breeding practices. Most breeders surveyed (76% reported specialising in one breed of dog, the median number of dogs and bitches per breeder was two and three respectively, and most breeders bred two litters or less a year. We identified four components, relating to the dam, that were considered important to breeders. These were defined as Maternal Care, Offspring Potential, Dam Temperament, and Dam Genetics and Health. Overall, differences were observed in attitudes and beliefs across these components, showing that there is variation according to breed/breed groups. In particular, the importance of Maternal Care varied according to dog breed group. Breeders of brachycephalic breeds tended to differ the most in relation to Offspring Potential and Dam Genetics and Health. The number of breeding dogs/bitches influenced breeding priority, especially in relation to Dam Temperament, however no effect was found relating to the number of puppies bred each year. Only 24% of breeders used their own sire for breeding. The finding that some breeders did not test for diseases relevant to their breed, such as hip dysplasia in Labrador Retrievers and German Shepherds, provides important information on the need to educate some breeders, and also buyers of purebred puppies, that screening for significant diseases should occur. Further research into the selection of breeding dams

  13. The mathematics of dam safety

    Energy Technology Data Exchange (ETDEWEB)

    Widmann, R. [Osterreichische Gesellschaft fuer Geomechanik, Salzburg (Austria)

    1997-05-01

    The safety of a dam is determined by its design, construction and supervision during operation. High arch dam failures have dropped dramatically since the early part of this century. An essential part of the success story relates to improved measurement techniques that can detect earlier unexpected behaviour that may lead to failure. (UK)

  14. Evaluatie Dam tot Damloop 2014

    NARCIS (Netherlands)

    Deutekom-Baart de la Faille, Marije

    In het weekend van 20 en 21 september 2014 vond de 30ste editie van de Dam tot Damloop plaats. Onderzoekers van de Hogeschool van Amsterdam en Hogeschool Inholland hebben bij de Dam tot Damloop een evaluatieonderzoek uitgevoerd met als doel het vinden van aanknopingspunten voor het structureel

  15. Prenatal air pollution exposure induces sexually dimorphic fetal programming of metabolic and neuroinflammatory outcomes in adult offspring.

    Science.gov (United States)

    Bolton, Jessica L; Auten, Richard L; Bilbo, Staci D

    2014-03-01

    Environmental chemical exposures during critical windows of development may contribute to the escalating prevalence of obesity. We tested the hypothesis that prenatal exposure to diesel exhaust particles (DEP), a primary component of air pollution, would prime microglia long-term, resulting in exacerbated metabolic and affective outcomes following exposure to a high-fat diet in adulthood. Time-mated mouse dams were intermittently exposed to respiratory instillations of either vehicle (VEH) or DEP throughout gestation. Adult male and female offspring were then fed either a low-fat diet (LFD) or high-fat diet (HFD) for 9 weeks. The male offspring of DEP-exposed dams exhibited exaggerated weight gain, insulin resistance, and anxiety-like behavior on HFD compared to the male offspring of VEH-exposed dams, whereas female offspring did not differ according to prenatal treatment. Furthermore, HFD induced evidence of macrophage infiltration of both adipose tissue and the brain in both sexes, but these cells were more activated specifically in DEP/HFD males. DEP/HFD males also expressed markedly higher levels of microglial/macrophage, but not astrocyte, activation markers in the hippocampus, whereas females exhibited only a suppression of astrocyte activation markers due to HFD. In a second experiment, DEP male offspring mounted an exaggerated peripheral IL-1β response to an LPS challenge at postnatal day (P)30, whereas their central IL-1β response did not differ from VEH male offspring, which is suggestive of macrophage priming due to prenatal DEP exposure. In sum, prenatal air pollution exposure "programs" offspring for increased susceptibility to diet-induced metabolic, behavioral, and neuroinflammatory changes in adulthood in a sexually dimorphic manner. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. War damages and reconstruction of Peruca dam

    International Nuclear Information System (INIS)

    Nonveiller, E.; Sever, Z.

    1999-01-01

    The paper describes the heavy damages caused by blasting in the Peruca rockfill dam in Croatia in January 1993. Complete collapse of the dam by overtopping was prevented through quick action of the dam owner by dumping clayey gravel on the lowest sections of the dam crest and opening the bottom outlet of the reservoir, thus efficiently lowering the water level. After the damages were sufficiently established and alternatives for restoration of the dam were evaluated, it was decided to construct a diaphragm wall through the damaged core in the central dam part as the impermeable dam element and to rebuild the central clay core at the dam abutments. Reconstruction works are described

  17. Propofol Exposure in Pregnant Rats Induces Neurotoxicity and Persistent Learning Deficit in the Offspring

    Directory of Open Access Journals (Sweden)

    Ming Xiong

    2014-05-01

    Full Text Available Propofol is a general anesthetic widely used in surgical procedures, including those in pregnant women. Preclinical studies suggest that propofol may cause neuronal injury to the offspring of primates if it is administered during pregnancy. However, it is unknown whether those neuronal changes would lead to long-term behavioral deficits in the offspring. In this study, propofol (0.4 mg/kg/min, IV, 2 h, saline, or intralipid solution was administered to pregnant rats on gestational day 18. We detected increased levels of cleaved caspase-3 in fetal brain at 6 h after propofol exposure. The neuronal density of the hippocampus of offspring was reduced significantly on postnatal day 10 (P10 and P28. Synaptophysin levels were also significantly reduced on P28. Furthermore, exploratory and learning behaviors of offspring rats (started at P28 were assessed in open-field trial and eight-arm radial maze. The offspring from propofol-treated dams showed significantly less exploratory activity in the open-field test and less spatial learning in the eight-arm radial maze. Thus, this study suggested that propofol exposure during pregnancy in rat increased cleaved caspsase-3 levels in fetal brain, deletion of neurons, reduced synaptophysin levels in the hippocampal region, and persistent learning deficits in the offspring.

  18. De Novo Genome and Transcriptome Assembly of the Canadian Beaver (Castor canadensis

    Directory of Open Access Journals (Sweden)

    Si Lok

    2017-02-01

    Full Text Available The Canadian beaver (Castor canadensis is the largest indigenous rodent in North America. We report a draft annotated assembly of the beaver genome, the first for a large rodent and the first mammalian genome assembled directly from uncorrected and moderate coverage (< 30 × long reads generated by single-molecule sequencing. The genome size is 2.7 Gb estimated by k-mer analysis. We assembled the beaver genome using the new Canu assembler optimized for noisy reads. The resulting assembly was refined using Pilon supported by short reads (80 × and checked for accuracy by congruency against an independent short read assembly. We scaffolded the assembly using the exon–gene models derived from 9805 full-length open reading frames (FL-ORFs constructed from the beaver leukocyte and muscle transcriptomes. The final assembly comprised 22,515 contigs with an N50 of 278,680 bp and an N50-scaffold of 317,558 bp. Maximum contig and scaffold lengths were 3.3 and 4.2 Mb, respectively, with a combined scaffold length representing 92% of the estimated genome size. The completeness and accuracy of the scaffold assembly was demonstrated by the precise exon placement for 91.1% of the 9805 assembled FL-ORFs and 83.1% of the BUSCO (Benchmarking Universal Single-Copy Orthologs gene set used to assess the quality of genome assemblies. Well-represented were genes involved in dentition and enamel deposition, defining characteristics of rodents with which the beaver is well-endowed. The study provides insights for genome assembly and an important genomics resource for Castoridae and rodent evolutionary biology.

  19. Stichorchis subtriquetrus (Digenea: Paramphistomatidae) from Eurasian beaver (Castor fiber) in the Czech Republic.

    Science.gov (United States)

    Máca, Ondřej; Pavlásek, Ivan; Vorel, Aleš

    2015-08-01

    Between March 2012 and April 2014, we performed post-mortem parasitological examinations of 11 Eurasian beavers (Castor fiber Linnaeus, 1758) from the basins of four main rivers (Dyje, Labe, Morava, Vltava) in the Czech Republic. The cause of death of five adult animals was unknown, three adult animals died after being hit by cars, while one young and one adult as a result of serious injuries and one juvenile male drowned. The trematode Stichorchis subtriquetrus (Rudolphi, 1814) Lühe, 1909 was only found in the caecum body and caecum apex of nine beavers (82%), with no significant differences in parasite intensity among beavers. The highest number of trematodes (271) occurred in an adult female in July 2013; while a range of 1-57 individuals were found in other positive beavers. S. subtriquetrus size in both parts of the caecum was 11.0-17.0 × 5.5-8.0 mm (mean 14.3 × 6.9 mm). Results demonstrated that for the optimal detection of eggs, it was necessary to examine at least 10 g of faeces with a new modified method of sedimentation. The size range of 30 eggs was 157.1-182.5 × 99.3-109.8 μm (mean 168.0 × 104.4 μm). There were no differences in prevalence and seasonal occurrence of S. subtriquetrus between male and female beavers. We did not find any other intestinal endoparasites or tissue parasites (Sarcocystis spp., Trichinella spp.).

  20. Damming evidence : Canada and the World Commission on Dams

    Energy Technology Data Exchange (ETDEWEB)

    Vert, P.; Parkinson, B.

    2003-06-01

    Large hydroelectric projects have been met with strong resistance from affected communities, particularly indigenous groups who have been displaced from their flooded communities following the damming of a river. The World Commission on Dams (WCD) was formed in 1998 to review the effectiveness of large dams and develop internationally acceptable guidelines and standards for large dams or hydro energy projects. The Canadian government, through the Canadian International Development Agency, was one of many governments to fund the WCD. However, the authors argue that despite the financial support, the Canadian government was absent from any effort to follow-up on the recommendations of the WCD. The seven strategic priorities in the decision making process include: (1) gaining public acceptance, (2) comprehensive option assessment of water, energy, food and development needs, (3) addressing existing dams to improve the benefits that can be derived from them, (4) sustaining livelihoods, (5) recognizing the entitlements and sharing benefits, (6) ensuring compliance, and (7) sharing rivers for peace, development and security. This report offers a means to assess planned or existing dams and presents a set of guidelines for good practices linked to the seven strategic priorities. Ten case studies from around the world were presented, including the Three Gorges Dam in China. 154 refs., 3 figs., 3 appendices.

  1. The impact of early postnatal environmental enrichment on maternal care and offspring behaviour following weaning.

    Science.gov (United States)

    Li, Ki Angel; Lund, Emilie Torp; Voigt, Jörg-Peter W

    2016-01-01

    The early postnatal period is a sensitive period in rodents as behavioural systems are developing and maturing during this time. However, relatively little information is available about the impact of environmental enrichment on offspring behaviour if enrichment is implemented only during this period. Here, environmental enrichment was provided from postnatal day 1 until weaning. On post-natal day 9, maternal behaviour and nonmaternal behaviour of the dam was observed. Nursing time in the enriched group was reduced but dams showed more non-maternal appetitive behaviours. Offspring were exposed to either the open field or the elevated plus maze (EPM) after weaning. In the open field, rats from the enriched group approached the more aversive inner zone of the open field later than control rats. Offspring from the enriched group made fewer entries into the inner zone and spent less time in this part of the arena. Enrichment had no impact on behaviour in the EPM. The present study provides evidence that postnatal enrichment can interfere with maternal behaviour in rats and can possibly lead to increased anxiety in the offspring. The findings suggest that enrichment procedures can have potentially unintended effects, interfering with the development of emotional behaviours in rats. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. High fructose consumption in pregnancy alters the perinatal environment without increasing metabolic disease in the offspring.

    Science.gov (United States)

    Lineker, Christopher; Kerr, Paul M; Nguyen, Patricia; Bloor, Ian; Astbury, Stuart; Patel, Nikhil; Budge, Helen; Hemmings, Denise G; Plane, Frances; Symonds, Michael E; Bell, Rhonda C

    2016-10-01

    Maternal carbohydrate intake is one important determinant of fetal body composition, but whether increased exposure to individual sugars has long-term adverse effects on the offspring is not well established. Therefore, we examined the effect of fructose feeding on the mother, placenta, fetus and her offspring up to 6 months of life when they had been weaned onto a standard rodent diet and not exposed to additional fructose. Dams fed fructose were fatter, had raised plasma insulin and triglycerides from mid-gestation and higher glucose near term. Maternal resistance arteries showed changes in function that could negatively affect regulation of blood pressure and tissue perfusion in the mother and development of the fetus. Fructose feeding had no effect on placental weight or fetal metabolic profiles, but placental gene expression for the glucose transporter GLUT1 was reduced, whereas the abundance of sodium-dependent neutral amino acid transporter-2 was raised. Offspring born to fructose-fed and control dams were similar at birth and had similar post-weaning growth rates, and neither fat mass nor metabolic profiles were affected. In conclusion, raised fructose consumption during reproduction results in pronounced maternal metabolic and vascular effects, but no major detrimental metabolic effects were observed in offspring up to 6 months of age.

  3. Maternal hyperthyroidism increases the susceptibility of rat adult offspring to cardiovascular disorders.

    Science.gov (United States)

    Lino, Caroline A; da Silva, Ivson Bezerra; Shibata, Caroline E R; Monteiro, Priscilla de S; Barreto-Chaves, Maria Luiza M

    2015-11-15

    Suboptimal intrauterine conditions as changed hormone levels during critical periods of the development are considered an insult and implicate in physiological adaptations which may result in pathological outcomes in later life. This study evaluated the effect of maternal hyperthyroidism (hyper) on cardiac function in adult offspring and the possible involvement of cardiac Renin-Angiotensin System (RAS) in this process. Wistar dams received orally thyroxin (12 mg/L) from gestational day 9 (GD9) until GD18. Adult offspring at postnatal day 90 (PND90) from hyper dams presented increased SBP evaluated by plethysmography and worse recovery after ischemia-reperfusion (I/R), as evidenced by decreased LVDP, +dP/dT and -dP/dT at 25 min of reperfusion and by increased infarct size. Increased cardiac Angiotensin I/II levels and AT1R in hyper offspring were verified. Herein, we provide evidences that maternal hyperthyroidism leads to altered expression of RAS components in adult offspring, which may be correlated with worse recovery of the cardiac performance after ischemic insults and hypertension. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Litter size reduction accentuates maternal care and alters behavioral and physiological phenotypes in rat adult offspring.

    Science.gov (United States)

    Enes-Marques, Silvia; Giusti-Paiva, Alexandre

    2018-01-27

    Maternal behavior has a substantial impact on the behavioral, endocrine, and neural development of the pups. This study investigated the effect of altering the neonatal nutritional environment by modifying the litter size on maternal care and anxiety- and fear-like behaviors in rats during adulthood. On postnatal day (PND) 2, litters were adjusted to a small litter (SL) size of three pups per dam or normal litter (NL) size of 12 pups per dam. Maternal behaviors were scored daily during lactation (PND2-21). The weight gain, food intake, adiposity, and biochemical landmarks of offspring rats were evaluated. On PND60, performances in the open field, elevated plus-maze (EPM), and fear conditioning test were measured. The reduction of the litter size enhanced maternal care in lactating rats, increasing the arched-back posture and licking pups. SL offspring exhibited accelerated weight gain, hyperphagia, increased visceral fat mass, dyslipidemia, and hyperleptinemia in adulthood. The SL offspring of both sexes showed an increase in the anti-thigmotactic effect in the open field, an intact anxious-phenotype in the EPM, and a decrease in the time spent freezing during the fear-conditioning test, compared to NL. The neonatal environment as determined by litter size plays a crucial role in programming the adult metabolic phenotype as well as behavioral responses to stressful stimuli, with an impact on anxiety-like and fear behaviors. These behavioral changes in offspring may be, at least in part, a result of increased maternal care.

  5. Prenatal ethanol enhances rotational behavior to apomorphine in the 24-month-old rat offspring with small striatal lesion.

    Science.gov (United States)

    Gomide, Vânia C; Chadi, Gerson

    2004-01-01

    Pregnant Wistar rats received a hyperproteic liquid diet containing 37.5% ethanol-derived calories during gestation. Isocaloric amount of liquid diet, with maltose-dextrin substituted for ethanol, was given to control pair-fed dams. Offsprings were allowed to survive until 24 months of age. A set of aged female offsprings of both control diet and ethanol diet groups was registered for spontaneous motor activity, by means of an infrared motion sensor activity monitor, or for apomorphine-induced rotational behavior, while another lot of male offsprings was submitted to an unilateral striatal small mechanical lesion by a needle, 6 days before rotational recordings. Prenatal ethanol did not alter spontaneous motor parameters like resting time as well as the events of small and large movements in the aged offsprings. Bilateral circling behavior was already increased 5 min after apomorphine in the unlesioned offsprings of both the control and ethanol diet groups. However, it lasted more elevated for 45- to 75-min time intervals in the gestational ethanol-exposed offsprings, while decreasing faster in the control offsprings. Apomorphine triggered a strong and sustained elevation of contraversive turns in the striatal-lesioned 24-month-old offsprings of the ethanol group, but only a small and transient elevation was seen in the offsprings of the control diet group. Astroglial and microglial reactions were seen surrounding the striatal needle track lesion. Microdensitometric image analysis demonstrated no differences in the levels of tyrosine hydroxylase immunoreactivity in the striatum of 24-month-old unlesioned and lesioned offsprings of control and alcohol diet groups. The results suggest that ethanol exposure during gestation may alter the sensitivity of dopamine receptor in aged offsprings, which is augmented by even a small striatal lesion.

  6. Olympic Dam Operations

    International Nuclear Information System (INIS)

    Crew, R.J.

    1992-01-01

    The Olympic Dam copper-uranium-gold-silver deposit in South Australia was discovered in 1975. The Mine is located 520 kilometres NNW of Adelaide, in South Australia. Following a six year period of intensive investigation and assessment of all the aspects required for the development of the deposit, the Joint Venturers decided in December, 1985, to proceed with the project. Milling of ore commenced in June 1988 and final products are cathode copper, uranium ore concentrate (yellow cake), and refined gold and silver. Anticipated production, from treating approximately 1.5 million tonnes of ore, in normal production years, is expected to be 45,000 tonnes of copper, 1,600 tonnes of yellow cake (1350 tonnes of Uranium), 25,000 ounces of gold and 500,000 ounces of silver. (orig./HP) [de

  7. Rehabilitation at Olympic Dam

    International Nuclear Information System (INIS)

    Chandler, W.P.; Middleton, B.A.

    1986-01-01

    Rehabilitation work on areas denuded of vegetation during the exploration phase of the Olympic Dam project was used to test various methods for regeneration of vegetation cover in the arid zone. The test work carried out on drill pads and access tracks has indicated that, with adequate site preparation, natural regeneration is the most economical and effective method to ensure post-operational stability of the affected land-forms. An on-going monitoring regime, utilising a computer data base, has been set up to allow year-to-year comparison of rehabilitation effectiveness. The database also provides a catalogue of initial colonising plants and a measure of variations in species diversity with time

  8. Technical specifications, Beaver Valley Power Station, Unit 2 (Docket No. 50-412): Appendix ''A'' to License No. NPF-73

    International Nuclear Information System (INIS)

    1987-08-01

    This report presents information concerning the Beaver Valley Power Station Unit 2 Reactor. Topics under discussion include: safety limits and limiting safety system settings; limiting condition for operation and surveillance requirements; design features; and administrative controls

  9. Deformation performance of Waba Dam

    Energy Technology Data Exchange (ETDEWEB)

    Salloum, T.; Bhardwaj, V.; Hassan, P. [Ontario Power Generation, Niagara-on-the-Lake, ON (Canada); Cragg, C. [Cragg Consulting Services, Toronto, ON (Canada)

    2009-07-01

    This paper described the performance of the Waba Dam which is being monitored as part of Ontario Power Generation's Dam Safety Program. It described the deformations that have been observed in this 3600 ft long earthfill dam which lies on marine clay in eastern Ontario. An extensive instrumentation program, including foundation settlement gauges, surface monuments, slope inclinometers, load cells and piezometers has been in effect since the construction of the dam in 1975. Significant settlement has occurred at Waba Dam since its construction. Wide berms were provided upstream and downstream beyond the slopes of the main fill to ensure stability of the dyke on the soft clay foundation and the crest elevations were designed to allow for the expected settlement in the foundation which would be overstressed by the dam loading. Based on current settlements, future settlements are predicted based on Asaoka's method. Inclinometer measurements have shown a foundation lateral spreading of 12 in. The lateral versus vertical deformations were found to be comparable to well behaving embankments reported in the literature. These analyses indicate that Waba Dam is performing well and should continue to perform well into the future. 8 refs., 1 tab., 14 figs.

  10. Public safety around dams guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, T [Canadian Dam Association, Edmonton, AB (Canada)

    2010-07-01

    This presentation discussed Canadian and international initiatives for improving dam safety and described some of the drivers for the development of new Canadian Dam Association (CDA) public safety guidelines for dams. The CDA guidelines were divided into the following 3 principal sections: (1) managed system elements, (2) risk assessment and management, and (3) technical bulletins. Public and media responses to the drownings have called for improved safety guidelines. While the public remains unaware of the hazards of dams, public interaction with dams is increasing as a result of interest in extreme sports and perceived rights of access. Guidelines are needed for dam owners in order to provide due diligence. Various organizations in Canada are preparing technical and public safety dam guidelines. CDA guidelines have also been prepared for signage, booms and buoys, and audible and visual alerts bulletins. Working groups are also discussing recommended practices for spill procedures, spillways and the role of professional engineers in ensuring public safety. Methods of assessing risk were also reviewed. Managed system elements for risk assessment and public interactions were also discussed, and stepped control measures were presented. tabs., figs.

  11. Effects of perinatal exposure to low doses of tributyltin chloride on pregnancy outcome and postnatal development in mouse offspring.

    Science.gov (United States)

    Si, Jiliang; Li, Jie; Zhang, Fengmei; Li, Guozhen; Xin, Quanbin; Dai, Bingqin

    2012-10-01

    Tributyltin (TBT), an endocrine-disrupting chemical, is well known to induce imposex in female gastropods. In this study, we assessed the effects of low doses of tributyltin chloride (TBTCl) on dams and their offspring. Pregnant mice were administered by gavage with 0, 1, 10, or 100 μg TBTCl/kg body weight/day from day 6 of pregnancy through the period of lactation. There were no TBT treatment-related deaths or clinical signs of toxicity for dams, and no treatment-related effects on body weight, litter sizes, gestational length of dams, and sex ratio, lactational body weight, postnatal survival, age at eruption of incisors, and eye opening of pups. However, at 100 μg/kg, TBTCl retarded the testes descent of male offspring. Behavioral tests showed a significant delay in cliff-drop aversion response in offspring of 10 and 100 μg/kg groups, but no significant difference in the righting reflex between control and TBT-exposed offspring was detectable. These results indicate that neurobehavioral toxicity seems to be one sensitive indicator to assess the risk of low doses of TBT. Copyright © 2011 Wiley Periodicals, Inc.

  12. Offspring predisposition to obesity due to maternal-diet-induced obesity in rats is preventable by dietary normalization before mating.

    Science.gov (United States)

    Castro, Heriberto; Pomar, Catalina Amadora; Palou, Andreu; Picó, Catalina; Sánchez, Juana

    2017-03-01

    We studied in rats whether the expected detrimental effects in offspring associated to maternal dietary obesity may be reverted by obesogenic diet removal 1 month before mating. Female rats were fed a cafeteria diet (CD) from days 10 to 100 and then a standard diet (SD) (postcafeteria rats). One month after CD removal, postcafeteria rats and a group of SD-fed female rats (controls) were mated with males. At weaning, offspring were fed SD and followed until 4 months old. CD was effective at inducing obesity in dams. Its removal led to a reduction in body weight, although, after 30 days, rats retained excess body weight and fat than controls. During lactation, postcafeteria dams showed greater body fat, and higher leptin and adiponectin levels in milk than controls. From 2 months of life, offspring of postcafeteria dams displayed lower body weight than controls, with no differences in the percentage of fat, homeostatic model assessment for insulin resistance, or circulating parameters. Removal of CD in obese rats before gestation, although without complete reversion of body weight excess, may prevent the expected detrimental effects in offspring associated to an excess fat accumulation in adulthood and the related metabolic disturbances. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Final Environmental Statement related to the operation of Beaver Valley Power Station, Unit 2 (Docket No. 50-412)

    International Nuclear Information System (INIS)

    1985-09-01

    This Final Environmental Statement contains the second assessment of the environmental impact associated with Beaver Valley Power Station Unit 2 pursuant to the National Environmental Policy Act of 1969 (NEPA) and Title 10 of the Code of Federal Regulations, Part 51, as amended, of the Nuclear Regulatory Commission regulations. This statement examines the environment, environmental consequences and mitigating actions, and environmental benefits and costs, and concludes that the action called for is the issuance of an operating license for Beaver Valley Unit 2

  14. Stable isotope and hydrogeochemical studies of Beaver Lake and Lake Radok, MacRobertson Land, East Antarctica

    International Nuclear Information System (INIS)

    Wand, U.; Hermichen, W.D.; Hoefling, R.; Muehle, K.

    1987-01-01

    Beaver Lake and Lake Radok, the largest known epishelf and the deepest freshwater lake on the Antarctic continent, respectively, were isotopically (δ 2 H, δ 18 O) and hydrogeochemically studied. Lake Radok is an isothermal and non-stratified, i.e. homogeneous water body, while Beaver Lake is stratified with respect to temperature, salinity and isotopic composition. The results for the latter attest to freshwater (derived from snow and glacier melt) overlying seawater. (author)

  15. Stable isotope and hydrogeochemical studies of Beaver Lake and Radok Lake, MacRobertson Land, East Antarctica

    International Nuclear Information System (INIS)

    Wand, U.; Hermichen, W.D.

    1988-01-01

    Beaver Lake and Radok Lake, the largest known epishelf lake and the deepest freshwater lake on the Antarctic continent, respectively, were isotopically (δ 2 H, δ 18 O) and hydrogeochemically studied. Radok Lake is an isothermal and nonstratified, i.e. homogeneous water body, while Beaver Lake is stratified with respect to temperature, salinity and isotopic composition. The results for the latter attest to freshwater (derived from snow and glacier melt) overlying seawater. (author)

  16. Proceedings of the Canadian Dam Association's 2006 annual conference: dams: past, present and future

    International Nuclear Information System (INIS)

    2006-01-01

    This conference addressed particular technical challenges regarding the operation of dams with particular focus on best practices for improving dam management and safety. It featured 4 workshops and a technical program led by experts on dams and tailings facilities that addressed topics such as dam construction, design and rehabilitation; dam management in a hydrological uncertainty context; monitoring, instrumentation and maintenance; dam behaviour; dam safety, dam failure and practical approaches to emergency preparedness planning for dam owners; historical aspects and environmental issues and conflicting water use. Recent developments in dam construction were reviewed along with discharge and debris management, tailings dam issues, asset management, seismic issues, public safety, seepage monitoring, flow control, dam rehabilitation, concrete testing, hydrotechnical issues, risk assessment methodology, and dam safety guidelines for extreme flood analyses and their applications. All 80 presentations from this conference have been catalogued separately for inclusion in this database. refs., tabs., figs

  17. 7 CFR 1724.55 - Dam safety.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Dam safety. 1724.55 Section 1724.55 Agriculture... § 1724.55 Dam safety. (a) The provisions of this section apply only to RUS financed electric system... for Dam Safety,”(Guidelines), as applicable. A dam, as more fully defined in the Guidelines, is...

  18. Using occupancy models to accommodate uncertainty in the interpretation of aerial photograph data: status of beaver in Central Oregon, USA

    Science.gov (United States)

    Pearl, Christopher A.; Adams, Michael J.; Haggerty, Patricia K.; Urban, Leslie

    2015-01-01

    Beavers (Castor canadensis) influence habitat for many species and pose challenges in developed landscapes. They are increasingly viewed as a cost-efficient means of riparian habitat restoration and water storage. Still, information on their status is rare, particularly in western North America. We used aerial photography to evaluate changes in beaver occupancy between 1942–1968 and 2009 in upper portions of 2 large watersheds in Oregon, USA. We used multiple observers and occupancy modeling to account for bias related to photo quality, observers, and imperfect detection of beaver impoundments. Our analysis suggested a slightly higher rate of beaver occupancy in the upper Deschutes than the upper Klamath basin. We found weak evidence for beaver increases in the west and declines in eastern parts of the study area. Our study presents a method for dealing with observer variation in photo interpretation and provides the first assessment of the extent of beaver influence in 2 basins with major water-use challenges. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  19. Managed flood effects on beaver pond habitat in a desert riverine ecosystem, bill williams river, Arizona USA

    Science.gov (United States)

    Andersen, D.C.; Shafroth, P.B.; Pritekel, C.M.; O'Neill, M. W.

    2011-01-01

    The ecological effects of beaver in warm-desert streams are poorly documented, but potentially significant. For example, stream water and sediment budgets may be affected by increased evaporative losses and sediment retention in beaver ponds. We measured physical attributes of beaver pond and adjacent lotic habitats on a regulated Sonoran Desert stream, the Bill Williams River, after ???11 flood-free months in Spring 2007 and Spring 2008. Neither a predicted warming of surface water as it passed through a pond nor a reduction in dissolved oxygen in ponds was consistently observed, but bed sediment sorted to finest in ponds as expected. We observed a river segment-scale downstream rise in daily minimum stream temperature that may have been influenced by the series of ??100 beaver ponds present. Channel cross-sections surveyed before and after an experimental flood (peak flow 65 m3/s) showed net aggradation on nine of 13 cross-sections through ponds and three of seven through lotic reaches. Our results indicate that beaver affect riverine processes in warm deserts much as they do in other biomes. However, effects may be magnified in deserts through the potential for beaver to alter the stream thermal regime and water budget. ?? Society of Wetland Scientists 2011.

  20. Effects of mountain beaver management and thinning on 15-year-old Douglas fir growth and survival.

    Science.gov (United States)

    Campbell, Dan L; Engeman, Richard M; Farley, James P

    2015-07-01

    We examined 4-year growth of 15-year-old damaged and undamaged Douglas fir (Pseudotsuga menzesii) after integrating temporary population reductions of mountain beaver (Aplodontia rufa) with thinning in a pre-commercial hand-planted plantation in western Washington. Five treatment combinations were considered: (1) trapping mountain beavers in an unthinned area, (2) trapping before thinning to 65 trees/ha (160 trees/ac), (3) no trapping and thinning to 65 trees/ha, (4) no trapping and thinning to 146 trees/ha (360 trees/ac), and (5) no trapping and no thinning. Removal of ≥ 90 % of mountain beavers temporarily reduced mountain beaver activity whether the stand was unthinned or thinned. Diameter growth at breast height (dbh) was greater for undamaged trees than for damaged trees in thinned areas. Tree height growth was greatest in trapped areas whether thinned or not. No differences were detected in 4-year survival between trees damaged aboveground and those without aboveground damage, which may be related to undetected root damage to trees without aboveground damage. Basal diameter growth and dbh growth were greatest for areas thinned to 65 trees/ha. Seventy-eight percent of stomachs from mountain beaver trapped in winter contained Douglas fir root or stem materials. Overall, short-term removal of mountain beavers integrated with pre-commercial thinning promoted growth of crop trees.

  1. Ethanol Consumption by Wistar Rat Dams Affects Selenium Bioavailability and Antioxidant Balance in Their Progeny

    Directory of Open Access Journals (Sweden)

    Olimpia Carreras

    2009-07-01

    Full Text Available Ethanol consumption affects maternal nutrition, the mothers’ antioxidant balance and the future health of their progeny. Selenium (Se is a trace element cofactor of the enzyme glutathione peroxidase (GPx. We will study the effect of ethanol on Se bioavailability in dams and in their progeny. We have used three experimental groups of dams: control, chronic ethanol and pair-fed; and three groups of pups. Se levels were measured by graphite-furnace atomic absorption spectrometry. Serum and hepatic GPx activity was determined by spectrometry. We have concluded that ethanol decreased Se retention in dams, affecting their tissue Se deposits and those of their offspring, while also compromising their progeny’s weight and oxidation balance. These effects of ethanol are caused by a reduction in Se intake and a direct alcohol-generated oxidation action.

  2. Maternal Dietary Supplementation with Oligofructose-Enriched Inulin in Gestating/Lactating Rats Preserves Maternal Bone and Improves Bone Microarchitecture in Their Offspring

    Science.gov (United States)

    Diaz-Castro, Javier; López-Aliaga, Inmaculada; Rueda, Ricardo

    2016-01-01

    Nutrition during pregnancy and lactation could exert a key role not only on maternal bone, but also could influence the skeletal development of the offspring. This study was performed in rats to assess the relationship between maternal dietary intake of prebiotic oligofructose-enriched inulin and its role in bone turnover during gestation and lactation, as well as its effect on offspring peak bone mass/architecture during early adulthood. Rat dams were fed either with standard rodent diet (CC group), calcium-fortified diet (Ca group), or prebiotic oligofructose-enriched inulin supplemented diet (Pre group), during the second half of gestation and lactation. Bone mineral density (BMD) and content (BMC), as well as micro-structure of dams and offspring at different stages were analysed. Dams in the Pre group had significantly higher trabecular thickness (Tb.Th), trabecular bone volume fraction (BV/TV) and smaller specific bone surface (BS/BV) of the tibia in comparison with CC dams. The Pre group offspring during early adulthood had an increase of the lumbar vertebra BMD when compared with offspring of CC and Ca groups. The Pre group offspring also showed significant increase versus CC in cancellous and cortical structural parameters of the lumbar vertebra 4 such as Tb.Th, cortical BMD and decreased BS/BV. The results indicate that oligofructose-enriched inulin supplementation can be considered as a plausible nutritional option for protecting against maternal bone loss during gestation and lactation preventing bone fragility and for optimizing peak bone mass and architecture of the offspring in order to increase bone strength. PMID:27115490

  3. Maternal obesity in the rat programs male offspring exploratory, learning and motivation behavior: prevention by dietary intervention pre-gestation or in gestation.

    Science.gov (United States)

    Rodriguez, J S; Rodríguez-González, G L; Reyes-Castro, L A; Ibáñez, C; Ramírez, A; Chavira, R; Larrea, F; Nathanielsz, P W; Zambrano, E

    2012-04-01

    We studied the effects of maternal high fat diet (HFD, 25% calories from fat administered before and during pregnancy and lactation) and dietary intervention (switching dams from HFD to control diet) at different periconceptional periods on male offspring anxiety related behavior, exploration, learning, and motivation. From weaning at postnatal day (PND) 21, female subjects produced to be the mothers in the study received either control diet (CTR - 5% calories from fat), HFD through pregnancy and lactation (MO), HFD during PNDs 21-90 followed by CTR diet (pre-gestation (PG) intervention) or HFD from PND 21 to 120 followed by CTR diet (gestation and lactation (G) intervention) and bred at PND 120. At 19 days of gestation maternal serum corticosterone was increased in MO and the PG and G dams showed partial recovery with intermediate levels. In offspring, no effects were found in the elevated plus maze test. In the open field test, MO and G offspring showed increase zone entries, displaying less thigmotaxis; PG offspring showed partial recuperation of this behavior. During initial operant conditioning MO, PG and G offspring displayed decreased approach behavior with subsequent learning impairment during the acquisition of FR-1 and FR-5 operant conditioning for sucrose reinforcement. Motivation during the progressive ratio test increased in MO offspring; PG and G intervention recuperated this behavior. We conclude that dietary intervention can reverse negative effects of maternal HFD and offspring outcomes are potentially due to elevated maternal corticosterone. Copyright © 2012 ISDN. Published by Elsevier Ltd. All rights reserved.

  4. Perspectives on dam safety in Canada

    International Nuclear Information System (INIS)

    Halliday, R.

    2004-01-01

    Canadian dam safety issues were reviewed from the perspective of a water resources engineer who is not a dam safety practitioner. Several external factors affecting dam safety were identified along with perceived problems in dam safety administration. The author claims that the main weakness in safety practices can be attributed to provincial oversights and lack of federal engagement. Some additions to the Canadian Dam Safety Guidelines were proposed to address these weaknesses. Canada has hundreds of large dams and high hazard dams whose failure would result in severe downstream consequences. The safety of dams built on boundary waters shared with the United States have gained particular attention from the International Joint Commission. This paper also examined safety criteria for concerns such as aging dams, sabotage and global climate change that may compromise the safety of a dam. 26 refs

  5. Dams and Levees: Safety Risks

    Science.gov (United States)

    Carter, N. T.

    2017-12-01

    The nation's flood risk is increasing. The condition of U.S. dams and levees contributes to that risk. Dams and levee owners are responsible for the safety, maintenance, and rehabilitation of their facilities. Dams-Of the more than 90,000 dams in the United States, about 4% are federally owned and operated; 96% are owned by state and local governments, public utilities, or private companies. States regulate dams that are not federally owned. The number of high-hazard dams (i.e., dams whose failure would likely result in the loss of human life) has increased in the past decade. Roughly 1,780 state-regulated, high-hazard facilities with structural ratings of poor or unsatisfactory need rehabilitation. Levees-There are approximately 100,000 miles of levees in the nation; most levees are owned and maintained by municipalities and agricultural districts. Few states have levee safety programs. The U.S. Army Corps of Engineers (Corps) inspects 15,000 miles of levees, including levees that it owns and local levees participating in a federal program to assist with certain post-flood repairs. Information is limited on how regularly other levees are inspected. The consequence of a breach or failure is another aspect of risk. State and local governments have significant authority over land use and development, which can shape the social and economic impacts of a breach or failure; they also lead on emergency planning and related outreach. To date, federal dam and levee safety efforts have consisted primarily of (1) support for state dam safety standards and programs, (2) investments at federally owned dams and levees, and (3) since 2007, creation of a national levee database and enhanced efforts and procedures for Corps levee inspections and assessments. In Public Law 113-121, enacted in 2014, Congress (1) directed the Corps to develop voluntary guidelines for levee safety and an associated hazard potential classification system for levees, and (2) authorized support for the

  6. Grouting Applications in Cindere Dam

    Directory of Open Access Journals (Sweden)

    Devrim ALKAYA

    2011-01-01

    Full Text Available Grouting is one of the most popular method to control the water leakage in fill dam constructions. With this regard this method is widely used in all the world. Geological and geotechnical properties of rock are important parameters affect the design of grouting. In this study, geotechnical properties of Cindere Dam's base rock and the grouting prosedure have been investigated with grouting pressure.

  7. Ririe Dam Release Test Assessment

    Science.gov (United States)

    2013-06-01

    Notes HEC - RAS Location Station (ft) Observation Notes 1420 Ririe Dam Ririe Dam 119,880 Gates opened and initial release started. 1455 115th St...16°F air temperature. Table A2. Observations made on 11 February 2013. Time Location Notes HEC - RAS Location Station (ft) Observation Notes...ERDC/CRREL TR-13-10 52 Time Location Notes HEC - RAS Location Station (ft) Observation Notes Travel Time* (sec) Vel.** (fps) 1224 5th

  8. Effects of bromantan on offspring maturation and development of reflexes.

    Science.gov (United States)

    Iezhitsa, I N; Spasov, A A; Bugaeva, L I

    2001-01-01

    Bromantan (N-[2-adamantil]-N-[para-bromphenyl]amine) is an "actoprotective" drug widely used in Russia as a muscle performance-enhancing agent for sportsmen and as an immunostimulator in medicine. Experiments were conducted to determine whether this compound has adverse effects on the reproduction and development of offspring. Sexually mature female rats, weighing 180-200 g, were orally given bromantan at doses of 30 mg/kg (30-mg/kg group), 150 mg/kg (150-mg/kg group) and 600 mg/kg (600-mg/kg group) daily for 16 days, while the controls received the vehicle, amylaceous solution. Afterwards, treated females were mated with untreated males. The body weight change of the pregnant rats was monitored, as well as the length of gestation, litter size, sex ratio and number of stillborn. The offsprings were weighed and observed for external malformations, abnormalities of conditioned and unconditioned reflexes and open-field behaviour. Observation of rat dams revealed that their general state and activity in all groups did not differ significantly both during and after bromantan treatment. Bromantan had no adverse effects on body weight and gestation length of dams. Number of dams delivered per group did not differ from controls. There were stillborn rat pups in all litters, but the control group had less. One dam in the first group delivered a rat pup with a head hematoma. Litter size of the 30- and 600-mg/kg groups was decreased (by 34.9% and 44.2%, respectively) and increased in the 150-mg/kg group (by 45.1%, POpen-field testing (PND 40) resulted in an insignificant decrease of exploratory and locomotor behaviors for the 30-, 150- and 600-mg/kg groups. The number of grooming episodes was insignificantly decreased for the 30-mg/kg group and insignificantly increased for the 600-mg/kg group. In the passive avoidance testing, on the retention day (72 h later), entry latency for rat pups in the 30-, 150- and 600-mg/kg groups increased by 259.0%, 175.3% and 160

  9. Breeding of Djungarian hamsters (Phodopus sungorus): influence of parity and litter size on weaning success and offspring sex ratio.

    Science.gov (United States)

    Lerchl, A

    1995-04-01

    The reproduction of 368 breeding pairs of Djungarian hamsters (Phodopus sungorus) has been recorded and evaluated during 5 consecutive years. Three-hundred-and-eight pairs (= 83.7%) were successful breeders giving birth to 2113 litters (up to 13 per dam) with a total of 12,591 offspring (mean: 6.0 +/- 2.2 [+/- SD] per litter). One-hundred-and-fifty dams delivered within 25 days after pairing, indicating a breeding success in the first oestrous cycle of 40.8% of all pairs (95% confidence interval: 35.7%-46.0%). The average number of offspring was higher in the 2nd than in the first litter, reaching a maximum in the 3rd (6.8 +/- 2.0), and decreasing thereafter. The loss of offspring (mean: 24.2%) was higher in older parents and influenced by the number of offspring per litter, indicating that experience and stress contribute to breeding success. A small, but significantly higher number of females was recorded only when no loss of offspring occurred until weaning (females: 2.36 +/- 1.75; males: 2.16 +/- 1.63, P sex ratio towards favouring females with increased litter numbers, in contrast to the predictions of the Trivers-Willard hypothesis, at least with respect to the species and the breeding conditions as described in this report. Since all breeders were kept under long-day type photoperiods (16L:8D), no signs of seasonality in breeding outcome were noted.

  10. Ingestion of carbohydrate-rich supplements during gestation programs insulin and leptin resistance but not body weight gain in adult rat offspring

    Directory of Open Access Journals (Sweden)

    Bernard eBeck

    2012-06-01

    Full Text Available Prenatal nutritional conditions can predispose to development of obesity and metabolic syndrome in adulthood. Gestation with its important hormonal status modification is a period of changes in usual feeding habits with pulses or avoidance for certain categories of food. We tried to mimic in an animal model some changes in food consumption patterns observed in pregnant women. For this purpose, Long-Evans female rats were fed during the dark period, their usual pre-gestational food quantity, and were allowed to complete their intake with either a control (Cr, high-fat (HF, or high-carbohydrate (HC diet available ad libitum during the light period. Dams fed a control diet ad libitum (Ca served as controls. Body weight and composition, food intake, and metabolic hormones (insulin, leptin were recorded in male offspring until 20 weeks after birth. Cr and HC females ate less than Ca females ( -16%; p<0.001 and their offspring presented a weight deficit from birth until 6 (HC group and 10 (Cr group weeks of age (p<0.05 or less. Plasma leptin corresponded to low body weight in Cr offspring, but was increased in HC offspring that in addition, had increased plasma insulin, blood glucose and subcutaneous adipose tissue mass. HF dams ate more than Ca dams (+13%;p<0.001, but plasma leptin and insulin were similar in their offspring. Hypothalamic Ob-Rb expression was increased in Cr, HC and HF offspring (+33-100% vs. Ca; p<0.05 or less. HC supplement ingestion during gestation leads therefore to insulin and leptin resistance in adult offspring independently of lower birth weight. These hormonal changes characterize obesity-prone animals. We therefore suggest to be heedful of the carbohydrate content in the diet during the last weeks (or months preceding delivery to limit development of later metabolic disorders in offspring.

  11. Polybrominated Diphenyl Ethers Orally Administration to Mice Were Tansferred to Offspring during Gestation and Lactation with Disruptions on the Immune System.

    Science.gov (United States)

    Hong, Soon Keun; Sohn, Kyung Hee; Kim, In Young; Lee, Jong Kwon; Ju, Jung Hun; Kim, Jin Ho; Lim, Chae Hyung; Han, Beom Seok; Jung, Hwa Chul; Lee, Jin Yong; Park, Kui Lea

    2010-04-01

    The present study was undertaken to examine the immunological effects of pentabrominated diphenyl ether (penta-BDE) and decabrominated diphenyl ether (deca-BDE) on the immune system of the dams and the developmental immune system of the offsprings. In this study, mated female C57BL/6J mice were orally administered penta-BDE, deca-BDE or corn oil for 5 weeks, from gestational day 6 to lactational day 21. The body weight of PND21 exposed to penta-BDE was significantly decreased relative to control mice, but that of post-natal day 63 (PND63) were recovered. Orally dosed dams with penta-BDE had significantly smaller absolute and relative spleen masses than control mice. Absolute and relative spleen and thymus masses of PND21 exposed to penta-BDE were significantly decreased over control. The exposure of dams and PND21 with penta-BDE reduced the number of splenocytes and thymocytes. As results of hematologic analysis, percentage WBC and percentage neutrophils increased in dams with deca-BDE. Splenic T cell proliferation in dams and PND21 exposed to penta-BDE was increased, and there were no significant difference in splenic B cell proliferation in all treatment groups. As results of flow cytometric analysis of splenocyte, percentage total T cell, Th cell and Tc cell in PND21 exposed to penta-BDE was slightly increased, and percentage macrophage in dams and PND21 exposed to deca-BDE was decreased. The ELISA results of antibody production show no significant difference in all treatment groups relative to controls. These results imply that PBDEs given to the dam were transferred to the offspring during gestation and lactation, and PBDEs transferred from the dam affect immune system of offspring.

  12. Errors associated with moose-hunter counts of occupied beaver Castor fiber lodges in Norway

    OpenAIRE

    Parker, Howard; Rosell, Frank; Gustavsen, Per Øyvind

    2002-01-01

    In Norway, Sweden and Finland moose Alces alces hunting teams are often employed to survey occupied beaver (Castor fiber and C. canadensis) lodges while hunting. Results may be used to estimate population density or trend, or for issuing harvest permits. Despite the method's increasing popularity, the errors involved have never been identified. In this study we 1) compare hunting-team counts of occupied lodges with total counts, 2) identify the sources of error between counts and 3) evaluate ...

  13. Forest disturbance by an ecosystem engineer: beaver in boreal forest landscapes

    OpenAIRE

    Nummi, Petri; Kuuluvainen, Timo

    2013-01-01

    Natural disturbances are important for forest ecosystem dynamics and maintenance of biodiversity. In the boreal forest, large-scale disturbances such as wildfires and windstorms have been emphasized, while disturbance agents acting at smaller scales have received less attention. Especially in Europe beavers have long been neglected as forest disturbance agents because they were extirpated from most of their range centuries ago. However, now they are returning to many parts of their former dis...

  14. Impact of native ungulates and beaver on riparian communities in the intermountain west

    OpenAIRE

    Kay, Charles E.

    1994-01-01

    This paper reviews the impact native ungulates, primarily elk and moose, and beaver can have on riparian communities in the Western United States. In Yellowstone National Park and in other areas where ungulates are not managed, repeated browsing has reduced tall willow, aspen, and cottonwood communities by approximately 95 percent since the late 1800's. Native ungulates can also severely reduce or eliminate palatable grasses and forbs from herbaceous riparian communities. By eliminating woody...

  15. Maternal chromium restriction modulates miRNA profiles related to lipid metabolism disorder in mice offspring.

    Science.gov (United States)

    Zhang, Qian; Xiao, Xinhua; Zheng, Jia; Li, Ming; Yu, Miao; Ping, Fan; Wang, Zhixin; Qi, Cuijuan; Wang, Tong; Wang, Xiaojing

    2017-08-01

    Increasing evidence shows that maternal nutrition status has a vital effect on offspring susceptibility to obesity. MicroRNAs are related to lipid metabolism processes. This study aimed to evaluate whether maternal chromium restriction could affect miRNA expression involved in lipid metabolism in offspring. Weaning C57BL/6J mice born from mothers fed with normal control diet or chromium-restricted diet were fed for 13 weeks. The adipose miRNA expression profile was analyzed by miRNA array analysis. At 16 weeks old, pups from dams fed with chromium-restricted diet exhibit higher body weight, fat weight, and serum TC, TG levels. Six miRNAs were identified as upregulated in the RC group compared with the CC group, whereas eight miRNAs were lower than the threshold level set in the RC group. In the validated target genes of these differentially expressed miRNA, the MAPK signaling pathway serves an important role in the influence of early life chromium-restricted diet on lipid metabolism through miRNA. Long-term programming on various specific miRNA and MAPK signaling pathway may be involved in maternal chromium restriction in the adipose of female offspring. Impact statement For the first time, our study demonstrates important miRNA differences in the effect of maternal chromium restriction in offspring. These miRNAs may serve as "bridges" between the mother and the offspring by affecting the MAPK pathway.

  16. Methyl donor supplementation blocks the adverse effects of maternal high fat diet on offspring physiology.

    Directory of Open Access Journals (Sweden)

    Jesselea Carlin

    Full Text Available Maternal consumption of a high fat diet during pregnancy increases the offspring risk for obesity. Using a mouse model, we have previously shown that maternal consumption of a high fat (60% diet leads to global and gene specific decreases in DNA methylation in the brain of the offspring. The present experiments were designed to attempt to reverse this DNA hypomethylation through supplementation of the maternal diet with methyl donors, and to determine whether methyl donor supplementation could block or attenuate phenotypes associated with maternal consumption of a HF diet. Metabolic and behavioral (fat preference outcomes were assessed in male and female adult offspring. Expression of the mu-opioid receptor and dopamine transporter mRNA, as well as global DNA methylation were measured in the brain. Supplementation of the maternal diet with methyl donors attenuated the development of some of the adverse effects seen in offspring from dams fed a high fat diet; including weight gain, increased fat preference (males, changes in CNS gene expression and global hypomethylation in the prefrontal cortex. Notable sex differences were observed. These findings identify the importance of balanced methylation status during pregnancy, particularly in the context of a maternal high fat diet, for optimal offspring outcome.

  17. Maternal high fructose and low protein consumption during pregnancy and lactation share some but not all effects on early-life growth and metabolic programming of rat offspring.

    Science.gov (United States)

    Arentson-Lantz, Emily J; Zou, Mi; Teegarden, Dorothy; Buhman, Kimberly K; Donkin, Shawn S

    2016-09-01

    Maternal nutritional stress during pregnancy acts to program offspring metabolism. We hypothesized that the nutritional stress caused by maternal fructose or low protein intake during pregnancy would program the offspring to develop metabolic aberrations that would be exacerbated by a diet rich in fructose or fat during adult life. The objective of this study was to characterize and compare the fetal programming effects of maternal fructose with the established programming model of a low-protein diet on offspring. Male offspring from Sprague-Dawley dams fed a 60% starch control diet, a 60% fructose diet, or a low-protein diet throughout pregnancy and lactation were weaned onto either a 60% starch control diet, 60% fructose diet, or a 30% fat diet for 15 weeks. Offspring from low-protein and fructose-fed dam showed retarded growth (Pprotein dams (1.31 vs 0.89, 0.85; confidence interval, 0.78-1.04). Similarly, maternal fructose (P=.09) and low-protein (Pprotein restriction such as retarded growth, but is unique in programming of selected hepatic and intestinal transcripts. Copyright © 2016. Published by Elsevier Inc.

  18. Habitat Evaluation Procedures (HEP) Report : West Beaver Lake, 2004-2005 Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Entz, Ray

    2005-02-01

    On September 7, 2004, the Habitat Evaluation Procedure (HEP) was used to determine baseline habitat suitability on the West Beaver Lake property, an acquisition completed by the Kalispel Tribe of Indians in September 2004. Evaluation species and appropriate models include bald eagle, black-capped chickadee, mallard, muskrat, and white-tailed deer. Habitat Suitability Index (HSI) values were visually estimated and agreed upon by all HEP team members. The West Beaver Lake Project provides a total of 103.08 Habitat Units (HUs) for the species evaluated. Emergent wetland habitat provides 7.17 HUs for mallard and muskrat. Conifer forest habitat provides 95.91 HUs for bald eagle, black-capped chickadee, mallard, and white-tailed deer. The objective of using HEP at the West Beaver Lake Project and other protected properties is to document the quality and quantity of available habitat for selected wildlife species. In this way, HEP provides information on the relative value of the same area at future points in time so that the effect of management activities on wildlife habitat can be quantified. When combined with other tools, the baseline HEP will be used to determine the most effective on-site management, restoration, and enhancement actions to increase habitat suitability for targeted species. The same process will be replicated every five years to quantitatively evaluate the effectiveness of management strategies in improving and maintaining habitat conditions while providing additional crediting to BPA for enhanced habitat values.

  19. Parameterization of the ACRU model for estimating biophysical and climatological change impacts, Beaver Creek, Alberta

    Science.gov (United States)

    Forbes, K. A.; Kienzle, S. W.; Coburn, C. A.; Byrne, J. M.

    2006-12-01

    Multiple threats, including intensification of agricultural production, non-renewable resource extraction and climate change, are threatening Southern Alberta's water supply. The objective of this research is to calibrate/evaluate the Agricultural Catchments Research Unit (ACRU) agrohydrological model; with the end goal of forecasting the impacts of a changing environment on water quantity. The strength of this model is the intensive multi-layered soil water budgeting routine that integrates water movement between the surface and atmosphere. The ACRU model was parameterized using data from Environment Canada's climate database for a twenty year period (1984-2004) and was used to simulate streamflow for Beaver Creek. The simulated streamflow was compared to Environment Canada's historical streamflow database to validate the model output. The Beaver Creek Watershed, located in the Porcupine Hills southwestern Alberta, Canada contains a heterogeneous cover of deciduous, coniferous, native prairie grasslands and forage crops. In a catchment with highly diversified land cover, canopy architecture cannot be overlooked in rainfall interception parameterization. Preliminary testing of ACRU suggests that streamflows were sensitive to varied levels of leaf area index (LAI), a representative fraction of canopy foliage. Further testing using remotely sensed LAI's will provide a more accurate representation of canopy foliage and ultimately best represent this important element of the hydrological cycle and the associated processes which govern the natural hydrology of the Beaver Creek watershed.

  20. A novel papillomavirus isolated from proliferative skin lesions of a wild American beaver (Castor canadensis).

    Science.gov (United States)

    Rogovskyy, Artem S; Baszler, Timothy V; Bradway, Daniel S; Bruning, Darren L; Davitt, Christine M; Evermann, James F; Burk, Robert D; Chen, Zigui; Mansfield, Kristin G; Haldorson, Gary J

    2012-07-01

    Cutaneous papillomatosis was diagnosed in an adult American beaver (Castor canadensis). Gross lesions included numerous exophytic, roughly circular, lightly pigmented lesions on hairless areas of fore and hind feet and the nose. The most significant histopathologic findings were multifocal papilliform hyperplasia of the superficial stratified squamous epithelium, with multifocal koilocytes, and multiple cells with large, darkly basophilic intranuclear inclusion bodies. A virus with properties consistent with papillomavirus (PV) was recovered by virus isolation of skin lesions, utilizing rabbit and feline kidney cell lines. The presence of the virus was confirmed by PV-specific polymerase chain reaction. The partial sequences of E1 and L1 genes did not closely match those of any PVs in GenBank, suggesting that this might be a new type of PV. Partial E1 and L1 nucleotide sequences of the beaver papillomavirus (hereafter, ARbeaver-PV1) were used to create a phylogenetic tree employing the complete E1 and L1 open reading frame nucleotide sequences of 68 PVs. The phylogenetic tree placed the ARbeaver-PV1 in a clade that included the Mupapillomavirus (HPV1 and HPV63) and Kappapapillomavirus (OcPV1 and SfPV1) genera. The present article confirms the papillomaviral etiology of cutaneous exophytic lesions in the beaver.

  1. Feeding a diet devoid of choline to lactating rodents restricts growth and lymphocyte development in offspring.

    Science.gov (United States)

    Lewis, E D; Goruk, S; Richard, C; Dellschaft, N S; Curtis, J M; Jacobs, R L; Field, C J

    2016-09-01

    The nutrient choline is necessary for membrane synthesis and methyl donation, with increased requirements during lactation. The majority of immune development occurs postnatally, but the importance of choline supply for immune development during this critical period is unknown. The objective of this study was to determine the importance of maternal supply of choline during suckling on immune function in their offspring among rodents. At parturition, Sprague-Dawley dams were randomised to either a choline-devoid (ChD; n 7) or choline-sufficient (ChS, 1 g/kg choline; n 10) diet with their offspring euthanised at 3 weeks of age. In a second experiment, offspring were weaned to a ChS diet until 10 weeks of age (ChD-ChS, n 5 and ChS-ChS, n 9). Splenocytes were isolated, and parameters of immune function were measured. The ChD offspring received less choline in breast milk and had lower final body and organ weight compared with ChS offspring (P<0·05), but this effect disappeared by week 10 with choline supplementation from weaning. ChD offspring had a higher proportion of T cells expressing activation markers (CD71 or CD28) and a lower proportion of total B cells (CD45RA+) and responded less to T cell stimulation (lower stimulation index and less IFN-γ production) ex vivo (P<0·05). ChD-ChS offspring had a lower proportion of total and activated CD4+ T cells, and produced less IL-6 after mitogen stimulation compared with cells from ChS-ChS (P<0·05). Our study suggests that choline is required in the suckling diet to facilitate immune development, and choline deprivation during this critical period has lasting effects on T cell function later in life.

  2. The effects of maternal and post-weaning diet interaction on glucose metabolism and gut microbiota in male mice offspring

    Science.gov (United States)

    Zheng, Jia; Xiao, Xinhua; Zhang, Qian; Yu, Miao; Xu, Jianping; Qi, Cuijuan; Wang, Tong

    2016-01-01

    Substantial studies demonstrated that maternal nutrition can significantly determine the susceptibility to developing some metabolic diseases in offspring. However, investigations into the later-life effects of these diets on gut microbiota in the offspring are limited. Our objective was to explore the effects of maternal and post-weaning diet interaction on offspring's gut microbiota and glucose metabolism in later life. The male offspring of dams fed on either a high-fat (HF) diet or control (C) diet and then weaned to either a HF or C diet, generating four groups: C–C, HF–C, C–HF and HF–HF (n=8 in each group). The C–C offspring had lower body weight than C–HF group at 16 weeks of age (Pblood glucose (BG) levels of the male offspring from the C and HF dams weaned HF diet were significantly higher at 30 min, 60 min and 120 min (Pglucose administration compared with those of the C–C group. The C–HF group had higher BG at 30 min than HF–HF group (Pcurve (AUC) in C–HF and HF–HF groups was also significantly larger than C–C group (Pglucose response to a glucose load (Pglucose metabolism and alterations of gut microbiota in later life. Our study is novel in focusing on the effects of maternal and post-weaning diet interaction on offspring gut microbiota and glucose metabolism in later life. PMID:27129301

  3. Effects of maternal stress and perinatal fluoxetine exposure on behavioral outcomes of adult male offspring.

    Science.gov (United States)

    Kiryanova, V; Meunier, S J; Vecchiarelli, H A; Hill, M N; Dyck, R H

    2016-04-21

    Women of child-bearing age are the population group at highest risk for depression. In pregnant women, fluoxetine (Flx) is the most widely prescribed selective serotonin reuptake inhibitor (SSRI) used for the treatment of depression. While maternal stress, depression, and Flx exposure have been shown to effect neurodevelopment of the offspring, separately, combined effects of maternal stress and Flx exposure have not been extensively examined. The present study investigated the effects of prenatal maternal stress and perinatal exposure to the SSRI Flx on the behavior of male mice as adults. C57BL/6 dams exposed to chronic unpredictable stress from embryonic (E) day 4 to E18 and non-stressed dams were administered Flx (25 mg/kg/d) in the drinking water from E15 to postnatal day 12. A separate control group consisted of animals that were not exposed to stress or Flx. At 12 days of age, brain levels of serotonin were assessed in the male offspring. At two months of age, the male offspring of mothers exposed to prenatal stress (PS), perinatal Flx, PS and Flx, or neither PS or Flx, went through a comprehensive behavioral test battery. At the end of testing brain-derived neurotropic factor (BDNF) levels were assessed in the frontal cortex of the offspring. Maternal behavior was not altered by either stress or Flx treatment. Treatment of the mother with Flx led to detectible Flx and NorFlx levels and lead to a decrease in serotonin levels in pup brains. In the adult male offspring, while perinatal exposure to Flx increased aggressive behavior, prenatal maternal stress decreased aggressive behavior. Interestingly, the combined effects of stress and Flx normalized aggressive behavior. Furthermore, perinatal Flx treatment led to a decrease in anxiety-like behavior in male offspring. PS led to hyperactivity and a decrease in BDNF levels in the frontal cortex regardless of Flx exposure. Neither maternal stress or Flx altered offspring performance in tests of cognitive

  4. A maternal high-protein diet predisposes female offspring to increased fat mass in adulthood whereas a prebiotic fibre diet decreases fat mass in rats.

    Science.gov (United States)

    Hallam, Megan C; Reimer, Raylene A

    2013-11-14

    The negative effects of malnourishment in utero have been widely explored; the effects of increased maternal macronutrient intake are not known in relation to high fibre, and have been inconclusive with regard to high protein. In the present study, virgin Wistar dams were fed either a control (C), high-protein (40 %, w/w; HP) or high-prebiotic fibre (21·6 %, w/w; HF) diet throughout pregnancy and lactation. Pups consumed the C diet from 3 to 14·5 weeks of age, and then switched to a high-fat/sucrose diet for 8 weeks. A dual-energy X-ray absorptiometry scan and an oral glucose tolerance test were performed and plasma satiety hormones measured. The final body weight and the percentage of body fat were significantly affected by the interaction between maternal diet and offspring sex: weight and fat mass were higher in the female offspring of the HP v. HF dams. No differences in body weight or fat mass were seen in the male offspring. There was a significant sex effect for fasting and total AUC for ghrelin and fasting GIP, with females having higher levels than males. Liver TAG content and plasma NEFA were lower in the offspring of high-prebiotic fibre dams (HF1) than in those of high-protein dams (HP1) and control dams (C1). Intestinal expression of GLUT2 was decreased in HF1 and HP1 v. C1. The maternal HP and HF diets had lasting effects on body fat and hepatic TAG accumulation in the offspring, particularly in females. Whereas the HP diet predisposes to an obese phenotype, the maternal HF diet appears to reduce the susceptibility to obesity following a high-energy diet challenge in adulthood.

  5. Maternal protein restriction during lactation induces early and lasting plasma metabolomic and hepatic lipidomic signatures of the offspring in a rodent programming model.

    Science.gov (United States)

    Martin Agnoux, Aurore; El Ghaziri, Angélina; Moyon, Thomas; Pagniez, Anthony; David, Agnès; Simard, Gilles; Parnet, Patricia; Qannari, El Mostafa; Darmaun, Dominique; Antignac, Jean-Philippe; Alexandre-Gouabau, Marie-Cécile

    2018-05-01

    Perinatal undernutrition affects not only fetal and neonatal growth but also adult health outcome, as suggested by the metabolic imprinting concept. However, the exact mechanisms underlying offspring metabolic adaptations are not yet fully understood. Specifically, it remains unclear whether the gestation or the lactation is the more vulnerable period to modify offspring metabolic flexibility. We investigated in a rodent model of intrauterine growth restriction (IUGR) induced by maternal protein restriction (R) during gestation which time window of maternal undernutrition (gestation, lactation or gestation-lactation) has more impact on the male offspring metabolomics phenotype. Plasma metabolome and hepatic lipidome of offspring were characterized through suckling period and at adulthood using liquid chromatography-high-resolution mass spectrometry. Multivariate analysis of these fingerprints highlighted a persistent metabolomics signature in rats suckled by R dams, with a clear-cut discrimination from offspring fed by control (C) dams. Pups submitted to a nutritional switch at birth presented a metabolomics signature clearly distinct from that of pups nursed by dams maintained on a consistent perinatal diet. Control rats suckled by R dams presented transiently higher branched-chain amino acid (BCAA) oxidation during lactation besides increased fatty acid (FA) β-oxidation, associated with preserved insulin sensitivity and lesser fat accretion that persisted throughout their life. In contrast, IUGR rats displayed permanently impaired β-oxidation, associated to increased glucose or BCAA oxidation at adulthood, depending on the fact that pups experienced slow postnatal or catch-up growth, as suckled by R or C dams, respectively. Taken together, these findings provide evidence for a significant contribution of the lactation period in metabolic programming. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Maternal supplementation with conjugated linoleic acid in the setting of diet-induced obesity normalises the inflammatory phenotype in mothers and reverses metabolic dysfunction and impaired insulin sensitivity in offspring.

    Science.gov (United States)

    Segovia, Stephanie A; Vickers, Mark H; Zhang, Xiaoyuan D; Gray, Clint; Reynolds, Clare M

    2015-12-01

    Maternal consumption of a high-fat diet significantly impacts the fetal environment and predisposes offspring to obesity and metabolic dysfunction during adulthood. We examined the effects of a high-fat diet during pregnancy and lactation on metabolic and inflammatory profiles and whether maternal supplementation with the anti-inflammatory lipid conjugated linoleic acid (CLA) could have beneficial effects on mothers and offspring. Sprague-Dawley rats were fed a control (CD; 10% kcal from fat), CLA (CLA; 10% kcal from fat, 1% total fat as CLA), high-fat (HF; 45% kcal from fat) or high fat with CLA (HFCLA; 45% kcal from fat, 1% total fat as CLA) diet ad libitum 10days prior to and throughout gestation and lactation. Dams and offspring were culled at either late gestation (fetal day 20, F20) or early postweaning (postnatal day 24, P24). CLA, HF and HFCLA dams were heavier than CD throughout gestation. Plasma concentrations of proinflammatory cytokines interleukin-1β and tumour necrosis factor-α were elevated in HF dams, with restoration in HFCLA dams. Male and female fetuses from HF dams were smaller at F20 but displayed catch-up growth and impaired insulin sensitivity at P24, which was reversed in HFCLA offspring. HFCLA dams at P24 were protected from impaired insulin sensitivity as compared to HF dams. Maternal CLA supplementation normalised inflammation associated with consumption of a high-fat diet and reversed associated programming of metabolic dysfunction in offspring. This demonstrates that there are critical windows of developmental plasticity in which the effects of an adverse early-life environment can be reversed by maternal dietary interventions. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Maternal Phytosterol Supplementation during Pregnancy and Lactation Modulates Lipid and Lipoprotein Response in Offspring of apoE-Deficient Mice123

    Science.gov (United States)

    Rideout, Todd C; Movsesian, Cheryl; Tsai, Yi-Ting; Iqbal, Aadil; Raslawsky, Amy; Patel, Mulchand S

    2015-01-01

    Background: In utero exposure to excessive cholesterol has been shown to increase fetal plasma cholesterol concentration and predispose adult offspring to cardiovascular disease (CVD) risk. Because lipid-lowering drugs are contraindicated during pregnancy, natural cholesterol-lowering compounds may be a safe and effective alternative to reduce CVD risk in offspring born to hypercholesterolemic mothers. Objective: This study used the hypercholesterolemic apolipoprotein E–deficient (apoE−/−) mouse model to test the hypothesis that mothers supplemented with phytosterols during gestation and lactation would produce offspring with a more favorable lipid profile than offspring from unsupplemented mothers, despite having a genetic predisposition toward hypercholesterolemia. Methods: Sixteen female apoE−/− mice were randomly assigned to 2 diets fed throughout the gestation and lactation periods: a cholesterol-enriched diet (CH) (0.15%) or the cholesterol-enriched diet supplemented with phytosterols (CH/PS) (2%). Serum lipids and lipoproteins were measured by enzyme assay and nuclear magnetic resonance spectroscopy, respectively, and liver cholesterol was analyzed by GC. Results: Compared with the CH-fed dams at the end of lactation, phytosterol-supplemented dams displayed lower (P 0.05) in HDL cholesterol and triacylglycerol (TG) concentrations. Pups from phytosterol-fed dams demonstrated lower (P 0.05) in HDL cholesterol compared with pups from CH-fed dams. Furthermore, compared with pups from CH-fed dams, pups from phytosterol-supplemented dams displayed a lower (P phytosterols during gestation and lactation exhibit favorable liver and serum lipid responses compared with pups from unsupplemented mothers. PMID:26084365

  8. Maternal enrichment affects prenatal hippocampal proliferation and open-field behaviors in female offspring mice.

    Science.gov (United States)

    Maruoka, Takashi; Kodomari, Ikuko; Yamauchi, Rena; Wada, Etsuko; Wada, Keiji

    2009-04-17

    The maternal environment is thought to be important for fetal brain development. However, the effects of maternal environment are not fully understood. Here, we investigated whether enrichment of the maternal environment can influence prenatal brain development and postnatal behaviors in mice. An enriched environment is a housing condition with several objects such as a running wheel, tube and ladder, which are thought to increase sensory, cognitive and motor stimulation in rodents compared with standard housing conditions. First, we measured the number of BrdU-positive cells in the hippocampal dentate gyrus of fetuses from pregnant dams housed in an enriched environment. Our results revealed that maternal enrichment influences cell proliferation in the hippocampus of female, but not male, fetuses. Second, we used the open-field test to investigate postnatal behaviors in the offspring of dams housed in the enriched environment during pregnancy. We found that maternal enrichment significantly affects the locomotor activity and time spent in the center of the open-field in female, but not male, offspring. These results indicate that maternal enrichment influences prenatal brain development and postnatal behaviors in female offspring.

  9. Considerations regarding the occurence of the Eurasian Beaver (Castor fiber Linnaeus 1758 in the Danube Delta (Romania

    Directory of Open Access Journals (Sweden)

    ALEXE Vasile

    2012-09-01

    Full Text Available On its original Romanian name - breb, the Eurasian Beaver (Castor fiber extinct at us for almost two centuries and reintroduced in some areas of the country, at present is better known under the name of his North American relative, beaver. In the last decades, this specie has been reintroduced within in its old habitats from where itwas extinct, especially under the effect of human pressure. Since 1998, reinsertion actions took place in Romania, in many areas, the closest one to Danube Delta area being the lower part of Ialomita river. By 2011 epigraphic or paleozoology evidences about the presence of this mammalian into the actual Delta have not been found, except the Lower Danube, up to Isaccea, but also near Dobrogea Plateau in Murighiol area. Its last Paleontology evidences come from early medieval period. Until now, the actual delta was considered a territory inappropriate for the Eurasian Beaver, due to high fluctuations of the water levels. But, in April 2011, the spontaneous appearance of the European beaver near Maliuc area was proved, a copy killed by poachers. In July 2011, a Beaver injured after the collision with a boat was found and scientifically investigated. The future observations will have to document if this mammal extends its habitat up here or remains an erratic appearance. In case of success of spontaneous colonization, its consequences and effects on the environment in general and on biodiversity inparticular are required to be monitored.

  10. High Dietary Fat Intake during Lactation Promotes the Development of Social Stress-Induced Obesity in the Offspring of Mice.

    Science.gov (United States)

    Tsuduki, Tsuyoshi; Yamamoto, Kazushi; E, Shuang; Hatakeyama, Yu; Sakamoto, Yu

    2015-07-17

    This study examined how a maternal high-fat diet (HD) during lactation and exposure of offspring to isolation stress influence the susceptibility of offspring to the development of obesity. C57BL/6J mice were fed a commercial diet (CD) during pregnancy and a CD or HD during lactation. Male offspring were weaned at three weeks of age, fed a CD until seven weeks of age, and fed a CD or HD until 11 weeks of age. Offspring were housed alone (isolation stress) or at six per cage (ordinary circumstances). Thus, offspring were assigned to one of eight groups: dams fed a CD or HD during lactation and offspring fed a CD or HD and housed under ordinary circumstances or isolation stress. Serum corticosterone level was significantly elevated by isolation stress. High-fat feeding of offspring reduced their serum corticosterone level, which was significantly elevated by a maternal HD. A maternal HD and isolation stress had combined effects in elevating the serum corticosterone level. These findings suggest that a maternal HD during lactation enhances the stress sensitivity of offspring. White adipose tissue weights were significantly increased by a maternal HD and isolation stress and by their combination. In addition, significant adipocyte hypertrophy was induced by a maternal HD and isolation stress and exacerbated by their combination. Thus, a maternal HD and isolation stress promote visceral fat accumulation and adipocyte hypertrophy, accelerating the progression of obesity through their combined effects. The mechanism may involve enhanced fatty acid synthesis and lipid influx from blood into adipose tissue. These findings demonstrate that a maternal HD during lactation may increase the susceptibility of offspring to the development of stress-induced obesity.

  11. Insulin sensitivity is normalized in the third generation (F3 offspring of developmentally programmed insulin resistant (F2 rats fed an energy-restricted diet

    Directory of Open Access Journals (Sweden)

    Martin John F

    2008-10-01

    Full Text Available Abstract Background/Aims The offspring and grandoffspring of female rats fed low protein diets during pregnancy and lactation, but fed nutritionally adequate diets thereafter, have been shown to exhibit altered insulin sensitivity in adulthood. The current study investigates the insulin sensitivity of the offspring and grandoffspring of female rats fed low protein diets during pregnancy, and then maintained on energy-restricted diets post weaning over three generations. Methods Female Sprague Dawley rats (F0 were mated with control males and protein malnourished during pregnancy/lactation. F1 offspring were then weaned to adequate but energy-restricted diets into adulthood. F1 dams were fed energy-restricted diets throughout pregnancy/lactation. F2 offspring were also fed energy-restricted diets post weaning. F2 pregnant dams were maintained as described above. Their F3 offspring were split into two groups; one was maintained on the energy-restricted diet, the other was maintained on an adequate diet consumed ad libitum post weaning. Results F2 animals fed energy-restricted diets were insulin resistant (p ad libitum postweaning diets (p Conclusion Maternal energy-restriction did not consistently program reduced insulin sensitivity in offspring over three consecutive generations. The reasons for this remain unclear. It is possible that the intergenerational transmission of developmentally programmed insulin resistance is determined in part by the relative insulin sensitivity of the mother during pregnancy/lactation.

  12. Maternal high-protein diet during pregnancy, but not during suckling, induced altered expression of an increasing number of hepatic genes in adult mouse offspring.

    Science.gov (United States)

    Vanselow, Jens; Kucia, Marzena; Langhammer, Martina; Koczan, Dirk; Metges, Cornelia C

    2016-04-01

    Indirect effects of a high-protein maternal diet are not well understood. In this study, we analyzed short-term and sustainable effects of a prenatal versus early postnatal maternal high-protein diet on growth and hepatic gene expression in mouse offspring. Dams were exposed to an isoenergetic high-protein (HP, 40 % w/w) diet during pregnancy or lactation. Growth and hepatic expression profiles of male offspring were evaluated directly after weaning and 150 days after birth. Offspring from two dietary groups, high-protein diet during pregnancy and control diet during lactation (HPC), and control diet during pregnancy and high-protein diet during lactation (CHP), were compared with offspring (CC) from control-fed dams. Maternal CHP treatment was associated with sustained offspring growth retardation, but decreased numbers of affected hepatic genes in adults compared to weanlings. In contrast, offspring of the HPC group did not show persistent effects on growth parameters, but the number of affected hepatic genes was even increased at adult age. In both dietary groups, however, only a small subset of genes was affected in weanlings as well as in adults. We conclude that (1) prenatal and early postnatal maternal HP diet caused persistent, but (2) different effects and partially complementary trends on growth characteristics and on the hepatic transcriptome and associated pathways and that (3) only a small number of genes and associated upstream regulators might be involved in passing early diet-induced imprints to adulthood.

  13. Maternal exposure to an environmentally relevant dose of triclocarban results in perinatal exposure and potential alterations in offspring development in the mouse model.

    Directory of Open Access Journals (Sweden)

    Heather A Enright

    Full Text Available Triclocarban (TCC is among the top 10 most commonly detected wastewater contaminants in both concentration and frequency. Its presence in water, as well as its propensity to bioaccumulate, has raised numerous questions about potential endocrine and developmental effects. Here, we investigated whether exposure to an environmentally relevant concentration of TCC could result in transfer from mother to offspring in CD-1 mice during gestation and lactation using accelerator mass spectrometry (AMS. 14C-TCC (100 nM was administered to dams through drinking water up to gestation day 18, or from birth to post-natal day 10. AMS was used to quantify 14C-concentrations in offspring and dams after exposure. We demonstrated that TCC does effectively transfer from mother to offspring, both trans-placentally and via lactation. TCC-related compounds were detected in the tissues of offspring with significantly higher concentrations in the brain, heart and fat. In addition to transfer from mother to offspring, exposed offspring were heavier in weight than unexposed controls demonstrating an 11% and 8.5% increase in body weight for females and males, respectively. Quantitative real-time polymerase chain reaction (qPCR was used to examine changes in gene expression in liver and adipose tissue in exposed offspring. qPCR suggested alterations in genes involved in lipid metabolism in exposed female offspring, which was consistent with the observed increased fat pad weights and hepatic triglycerides. This study represents the first report to quantify the transfer of an environmentally relevant concentration of TCC from mother to offspring in the mouse model and evaluate bio-distribution after exposure using AMS. Our findings suggest that early-life exposure to TCC may interfere with lipid metabolism and could have implications for human health.

  14. Maternal exposure to an environmentally relevant dose of triclocarban results in perinatal exposure and potential alterations in offspring development in the mouse model.

    Science.gov (United States)

    Enright, Heather A; Falso, Miranda J S; Malfatti, Michael A; Lao, Victoria; Kuhn, Edward A; Hum, Nicholas; Shi, Yilan; Sales, Ana Paula; Haack, Kurt W; Kulp, Kristen S; Buchholz, Bruce A; Loots, Gabriela G; Bench, Graham; Turteltaub, Kenneth W

    2017-01-01

    Triclocarban (TCC) is among the top 10 most commonly detected wastewater contaminants in both concentration and frequency. Its presence in water, as well as its propensity to bioaccumulate, has raised numerous questions about potential endocrine and developmental effects. Here, we investigated whether exposure to an environmentally relevant concentration of TCC could result in transfer from mother to offspring in CD-1 mice during gestation and lactation using accelerator mass spectrometry (AMS). 14C-TCC (100 nM) was administered to dams through drinking water up to gestation day 18, or from birth to post-natal day 10. AMS was used to quantify 14C-concentrations in offspring and dams after exposure. We demonstrated that TCC does effectively transfer from mother to offspring, both trans-placentally and via lactation. TCC-related compounds were detected in the tissues of offspring with significantly higher concentrations in the brain, heart and fat. In addition to transfer from mother to offspring, exposed offspring were heavier in weight than unexposed controls demonstrating an 11% and 8.5% increase in body weight for females and males, respectively. Quantitative real-time polymerase chain reaction (qPCR) was used to examine changes in gene expression in liver and adipose tissue in exposed offspring. qPCR suggested alterations in genes involved in lipid metabolism in exposed female offspring, which was consistent with the observed increased fat pad weights and hepatic triglycerides. This study represents the first report to quantify the transfer of an environmentally relevant concentration of TCC from mother to offspring in the mouse model and evaluate bio-distribution after exposure using AMS. Our findings suggest that early-life exposure to TCC may interfere with lipid metabolism and could have implications for human health.

  15. Dams and Obstructions along Iowa's Canoe Routes

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This dataset represents obstruction to canoe and boat users of the canoe routes of Iowa. This may represent actual dams, rock dams (natural or man made), large...

  16. Douglas County Dam Breach Inundation Areas

    Data.gov (United States)

    Kansas Data Access and Support Center — Dam breach analysis provides a prediction of the extent and timing of flooding from a catastrophic breach of the dams. These results are sufficient for developing...

  17. Simulation of Breach Outflow for Earthfill Dam

    International Nuclear Information System (INIS)

    Razad, Azwin Zailti Abdul; Muda, Rahsidi Sabri; Sidek, Lariyah Mohd; Azia, Intan Shafilah Abdul; Mansor, Faezah Hanum; Yalit, Ruzaimei

    2013-01-01

    Dams have been built for many reasons such as irrigation, hydropower, flood mitigation, and water supply to support development for the benefit of human. However, the huge amount of water stored behind the dam can seriously pose adverse impacts to the downstream community should it be released due to unwanted dam break event. To minimise the potential loss of lives and property damages, a workable Emergency Response Plan is required to be developed. As part of a responsible dam owner and operator, TNB initiated a study on dam breach modelling for Cameron Highlands Hydroelectric Scheme to simulate the potential dam breach for Jor Dam. Prediction of dam breach parameters using the empirical equations of Froehlich and Macdonal-Langridge-Monopolis formed the basis of the modelling, coupled with MIKE 11 software to obtain the breach outflow due to Probable Maximum Flood (PMF). This paper will therefore discuss the model setup, simulation procedure and comparison of the prediction with existing equations.

  18. Technical bulletin : structural considerations for dam safety

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This technical bulletin discussed issues related to the safety assessment of concrete water-retaining structures and timber dams. Structures reviewed in the paper included gravity dams; buttress dams; arch dams; spillway structures; intake structures; power plants; roller compacted concrete dams; and timber dams. A variety of issues related to the loss of cohesive bond and discontinuities in bedrock foundations were reviewed with reference to issues related to compressive strength, tensile strength, and shear strength. Static failure modes and failure mechanisms related to dam failures were also described. Visual indicators for potential failures include abutment and foundation movement, seepage, and structure movements. Loading combinations were discussed, and performance indicators for gravity dams were provided. Methods of analysis for considering load characteristics, structure types and geological conditions were also discussed. Modelling techniques for finite element analysis were also included. 16 refs., 3 tabs., 5 figs.

  19. Effects of a high-fat diet during pregnancy and lactation are modulated by E. coli in rat offspring.

    Science.gov (United States)

    Fåk, F; Karlsson, C L J; Ahrné, S; Molin, G; Weström, B

    2012-05-01

    Microbial manipulations in early life can affect gut development and inflammatory status of the neonate. The maternal diet during pregnancy and lactation also influences the health of the offspring, but the impact of maternal high-fat (HF) feeding along with modulations of the gut microbiota on body weight, fat deposition and gut function in the offspring has been poorly studied. Rat dams were given access to either an HF or a standard low-fat diet during the last 2 weeks of pregnancy and during lactation and effects on body weight and gastrointestinal function were investigated in the 14-day-old offspring. To elucidate whether bacterial administration to the dam could modulate any effects of the diets in the rat pups, another group of dams were given Escherichia coli in their drinking water. Maternal HF feeding resulted in increased body and fat pad weights in the offspring, along with increased levels of the acute-phase protein, haptoglobin and decreased protein content and disaccharidase activities in the small intestine. The addition of E. coli further accentuated these responses in the young rats, which, in addition to higher body weights and increased fat deposition, also showed an increased intestinal permeability and elevated levels of haptoglobin. The present study demonstrates for the first time how bacterial administration to the maternal diet during the neonatal period can affect body weight and fat deposition in the offspring. The results point to a mechanistic link between the gut microbiota, increased intestinal permeability and metabolic endotoxemia, which appear to have led to increased adiposity in the young rats.

  20. Effects of the use of assisted reproductive technologies and an obesogenic environment on resistance artery function and diabetes biomarkers in mice offspring.

    Directory of Open Access Journals (Sweden)

    Francisco I Ramirez-Perez

    Full Text Available Maternal obesity affects the incidence of cardiovascular disease and diabetes in offspring. Also the use of assisted reproductive technologies (ART has been associated with cardiovascular deficiencies in offspring. Obese women often suffer from infertility and use ART to achieve a pregnancy, but the combined effects of maternal obesity and ART on cardiovascular health and incidence of diabetes in the offspring is not known. Here, we report the effects of the use of ART within an obesogenic environment, consisting of feeding a western diet (WD to dams and offspring, on resistance artery function and presence of diabetes biomarkers in juvenile mice offspring. Our results indicate that WD and ART interacted to induce endothelial dysfunction in mesenteric resistance arteries isolated from 7-week-old mice offspring. This was determined by presence of a reduced acetylcholine-induced dilation compared to controls. The arteries from these WD-ART mice also had greater wall cross-sectional areas and wall to lumen ratios indicative of vascular hypertrophic remodeling. Of the diabetes biomarkers measured, only resistin was affected by a WD×ART interaction. Serum resistin was significantly greater in WD-ART offspring compared to controls. Diet and sex effects were observed in other diabetes biomarkers. Our conclusion is that in mice the use of ART within an obesogenic environment interacts to favor the development of endothelial dysfunction in the resistance arteries of juvenile offspring, while having marginal effects on diabetes biomarkers.

  1. 78 FR 53494 - Dam Safety Modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams

    Science.gov (United States)

    2013-08-29

    ... Bar Dams AGENCY: Tennessee Valley Authority. ACTION: Issuance of Record of Decision. SUMMARY: This... the dam safety modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams. The notice of... Loudoun, Tellico, and Watts Bar Dams was published in the Federal Register on May 31, 2013. This...

  2. High maternal sodium intake alters sex-specific renal renin-angiotensin system components in newborn Wistar offspring.

    Science.gov (United States)

    Maia, D R R; Lopes, K L; Heimann, J C; Furukawa, L N S

    2016-01-28

    This study aimed to evaluate the systemic and renal renin-angiotensin-aldosterone system (RAAS) at birth in male and female offspring and in mothers fed a high sodium diet (HSD) before and during gestation. Female Wistar rats were fed a HSD (8.0% NaCl) or a normal sodium diet (1.3% NaCl) from 8 weeks of age until delivery of their first litter. Maternal body weight, tail blood pressure, and food and water intake were evaluated. The litter sizes were assessed, and the body and kidney weights of the offspring were measured. Both mothers and offspring were euthanized immediately following the birth of the pups to evaluate plasma renin activity (PRA), renal renin content (RRC), renal angiotensin-converting enzyme (ACE) activity, renal angiotensin (Ang) II content, serum aldosterone (ALDO) levels, and renal cortical and medullary renin messenger RNA expression. In mothers in the HSD group, water intake and kidney mass were higher, whereas renal ACE activity, Ang II, PRA, ALDO and RRC were decreased. In the offspring of HSD-fed dams, the body and kidney mass were lower in both genders, renal ACE activity was lower in females and renal Ang II was lower in males. PRA, RRC, renin gene expression and ALDO levels did not differ between the groups of offspring. The data presented herein showed that a maternal HSD during pregnancy induces low birth weight and a sex-specific response in the RAAS in offspring.

  3. Maternal Active Mastication during Prenatal Stress Ameliorates Prenatal Stress-Induced Lower Bone Mass in Adult Mouse Offspring.

    Science.gov (United States)

    Azuma, Kagaku; Ogura, Minori; Kondo, Hiroko; Suzuki, Ayumi; Hayashi, Sakurako; Iinuma, Mitsuo; Onozuka, Minoru; Kubo, Kin-Ya

    2017-01-01

    Chronic psychological stress is a risk factor for osteoporosis. Maternal active mastication during prenatal stress attenuates stress response. The aim of this study is to test the hypothesis that maternal active mastication influences the effect of prenatal stress on bone mass and bone microstructure in adult offspring. Pregnant ddY mice were randomly divided into control, stress, and stress/chewing groups. Mice in the stress and stress/chewing groups were placed in a ventilated restraint tube for 45 minutes, 3 times a day, and was initiated on day 12 of gestation and continued until delivery. Mice in the stress/chewing group were allowed to chew a wooden stick during the restraint stress period. The bone response of 5-month-old male offspring was evaluated using quantitative micro-CT, bone histomorphometry, and biochemical markers. Prenatal stress resulted in significant decrease of trabecular bone mass in both vertebra and distal femur of the offspring. Maternal active mastication during prenatal stress attenuated the reduced bone formation and increased bone resorption, improved the lower trabecular bone volume and bone microstructural deterioration induced by prenatal stress in the offspring. These findings indicate that maternal active mastication during prenatal stress can ameliorate prenatal stress-induced lower bone mass of the vertebra and femur in adult offspring. Active mastication during prenatal stress in dams could be an effective coping strategy to prevent lower bone mass in their offspring.

  4. Long-term parental methamphetamine exposure of mice influences behavior and hippocampal DNA methylation of the offspring.

    Science.gov (United States)

    Itzhak, Y; Ergui, I; Young, J I

    2015-02-01

    The high rate of methamphetamine (METH) abuse among young adults and women of childbearing age makes it imperative to determine the long-term effects of METH exposure on the offspring. We hypothesized that parental METH exposure modulates offspring behavior by disrupting epigenetic programming of gene expression in the brain. To simulate the human pattern of drug use, male and female C57Bl/6J mice were exposed to escalating doses of METH or saline from adolescence through adulthood; following mating, females continue to receive drug or saline through gestational day 17. F1 METH male offspring showed enhanced response to cocaine-conditioned reward and hyperlocomotion. Both F1 METH male and female offspring had reduced response to conditioned fear. Cross-fostering experiments have shown that certain behavioral phenotypes were modulated by maternal care of either METH or saline dams. Analysis of offspring hippocampal DNA methylation showed differentially methylated regions as a result of both METH in utero exposure and maternal care. Our results suggest that behavioral phenotypes and epigenotypes of offspring that were exposed to METH in utero are vulnerable to (a) METH exposure during embryonic development, a period when wide epigenetic reprogramming occurs, and (b) postnatal maternal care.

  5. WinDAM C earthen embankment internal erosion analysis software

    Science.gov (United States)

    Two primary causes of dam failure are overtopping and internal erosion. For the purpose of evaluating dam safety for existing earthen embankment dams and proposed earthen embankment dams, Windows Dam Analysis Modules C (WinDAM C) software will simulate either internal erosion or erosion resulting f...

  6. EVALUASI KEAMANAN DAM JATILUHUR BERBASIS INDEKS RESIKO

    Directory of Open Access Journals (Sweden)

    Avazbek Ishbaev

    2014-12-01

    Full Text Available The dams have very important roles to agricultural activities. Especially, West Java with 240,000 hectares of agricultural land, needs a good dam structure that can be used sustainably. Jatiluhur dam in Purwakarta, West Java is one of big dams in Indonesia which has important rules not only for Purwakarta but also for Jakarta, Karawang and Bekasi residents. A study and observation about safety and dam stability is needed to prevent any damage. The purpose of this research were to identify parameters that influenced dam safety and to evaluate dam reliability based on index tools. Analysis was done using risk index tools. The result showed that the condition of the dam of Jatiluhur is still satisfied with indicators, "Idam"-750. The total index risk was 127.22 and the safety factor was 83.04 out of 100. Therefore, Jatiluhur dam could be classified as safe and no need for particular treatments. Jatiluhur dam can be operated in normal condition or abnormal condition with periodic monitoring. Keywords: dam safety, evaluation, Jatiluhur Dam, risk index tools

  7. Dams life; La vie des barrages

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The paper reports on the conclusions of decennial and annual inspections of French dams. Dams surveillance is performed by the operators and consists in visual examinations and measurements. Concrete dams, in particular, always have more or less developed fissures with water sweating threw the concrete mass or the foundations. Old concrete often show low swelling phenomena which are measured too. (J.S.)

  8. 78 FR 62627 - Sam Rayburn Dam Rate

    Science.gov (United States)

    2013-10-22

    ..., Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative, Inc. (Contract No... Schedule SRD-08, Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative... ADMINISTRATION RATE SCHEDULE SRD-13 \\1\\ WHOLESALE RATES FOR HYDRO POWER AND ENERGY SOLD TO SAM RAYBURN DAM...

  9. Hyperglycaemia in pregnant rats causes sex-related vascular dysfunction in adult offspring: role of cyclooxygenase-2.

    Science.gov (United States)

    de Sá, Francine Gomes; de Queiroz, Diego Barbosa; Ramos-Alves, Fernanda Elizabethe; Santos-Rocha, Juliana; da Silva, Odair Alves; Moreira, Hicla Stefany; Leal, Geórgia Andrade; da Rocha, Marcelo Aurélio; Duarte, Gloria Pinto; Xavier, Fabiano Elias

    2017-08-01

    What is the central question of this study? Hyperglycaemia during pregnancy induces vascular dysfunction and hypertension in male offspring. Given that female offspring from other fetal programming models are protected from the effects of fetal insult, the present study investigated whether there are sex differences in blood pressure and vascular function in hyperglycaemia-programmed offspring. What is the main finding and its importance? We demonstrated that hyperglycaemia in pregnant rats induced vascular dysfunction and hypertension only in male offspring. We found sex differences in oxidative stress and cyclooxygenase-2-derived prostanoid production that might underlie the vascular dysfunction. These differences, particularly in resistance arteries, may in part explain the absence of hypertension in female offspring born to hyperglycaemic dams. Exposure to maternal hyperglycaemia induces hypertension and vascular dysfunction in adult male offspring. Given that female offspring from several fetal programming models are protected from the effects of fetal insult, in this study we analysed possible differences relative to sex in blood pressure and vascular function in hyperglycaemia-programmed offspring. Hyperglycaemia was induced on day 7 of gestation (streptozotocin, 50 mg kg -1 ). Blood pressure, acetylcholine and phenylephrine or noradrenaline responses were analysed in the aorta and mesenteric resistance arteries of 3-, 6- and 12-month-old male and female offspring. Thromboxane A 2 release was analysed with commercial kits and superoxide anion (O 2 - ) production by dihydroethidium-emitted fluorescence. Male but not female offspring of hyperglycaemic dams (O-DR) had higher blood pressure than control animals (O-CR). Contraction in response to phenylephrine increased and relaxation in response to acetylcholine decreased only in the aorta from 12-month-old male O-DR and not in age-matched O-CR. Contractile and vasodilator responses were preserved in both the

  10. Dam's design continues throughout construction

    Energy Technology Data Exchange (ETDEWEB)

    Lara E, R; Wulff, J G

    1979-11-01

    In spite of adverse site conditions, Arenal dam in Costa Rica was completed a year ahead of schedule. Historical data on local earthquake activity which was available in unusual detail reduced some uncertainties in design information. Other uncertainties regarding the complex foundation conditions were resolved as excavation and construction progressed.

  11. In Utero Exposure to Fine Particulate Matter Causes Hypertension Due to Impaired Renal Dopamine D1 Receptor in Offspring

    Directory of Open Access Journals (Sweden)

    Zhengmeng Ye

    2018-03-01

    Full Text Available Background/Aims: Adverse environment in utero can modulate adult phenotypes including blood pressure. Fine particulate matter (PM2.5 exposure in utero causes hypertension in the offspring, but the exact mechanisms are not clear. Renal dopamine D1 receptor (D1R, regulated by G protein-coupled receptor kinase type 4 (GRK4, plays an important role in the regulation of renal sodium transport and blood pressure. In this present study, we determined if renal D1R dysfunction is involved in PM2.5–induced hypertension in the offspring. Methods: Pregnant Sprague–Dawley rats were given an oropharyngeal drip of PM2.5 (1.0 mg/kg at gestation day 8, 10, and 12. The blood pressure, 24-hour sodium excretion, and urine volume were measured in the offspring. The expression levels of GRK4 and D1R were determined by immunoblotting. The phosphorylation of D1R was investigated using immunoprecipitation. Plasma malondialdehyde and superoxide dismutase levels were also measured in the offspring. Results: As compared with saline-treated dams, offspring of PM2.5-treated dams had increased blood pressure, impaired sodium excretion, and reduced D1R-mediated natriuresis and diuresis, accompanied by decreased renal D1R expression and GRK4 expression. The impaired renal D1R function and increased GRK4 expression could be caused by increased reactive oxidative stress (ROS induced by PM2.5 exposure. Administration of tempol, a redox-cycling nitroxide, for 4 weeks in the offspring of PM2.5-treated dam normalized the decreased renal D1R expression and increased renal D1R phosphorylation and GRK4 expression. Furthermore, tempol normalized the increased renal expression of c-Myc, a transcription factor that regulates GRK4 expression. Conclusions: In utero exposure to PM2.5 increases ROS and GRK4 expression, impairs D1R-mediated sodium excretion, and increases blood pressure in the offspring. These studies suggest that normalization of D1R function may be a target for the

  12. Large dams and risk management

    International Nuclear Information System (INIS)

    Cazelais, N.

    2003-01-01

    In July 1996, Quebec's Saguenay region was subjected to intensive rainfall which caused severe floods and uncontrolled release of several reservoirs, resulting in extensive damage to dam structures and reservoirs. The probability of occurrence for that disaster was 1:10,000. Following the disaster, the Quebec government established a dam management body entitled the Commission scientifique et technique sur la gestion des barrages, which pointed out several safety shortcomings of existing dams. Many were either very old or had undergone significant function change without being subsequently re-evaluated. A report by the Commission stated that damage following the floods could have been limited if the design and operating standards of the dams had been more stringent. A Dam Safety Act was adopted by the Quebec National Assembly on May 30, 2000 following recommendations to retain safer structures. The Act demands regular reporting of operating procedures. Seismic activity was noted as being a topic that requires in-depth examination since Quebec's St. Lawrence Valley, particularly the Charlevoix region, is one of Canada's largest seismic zones. The other is on the west coast in British Columbia. Earthquakes in Quebec are less intense than the ones in British Columbia, but they have higher frequency content which exerts a quasi-resonance wave effect which impacts roads, bridges, buildings and hydroelectric generating facilities. Hydro-Quebec is a public utility which owns 563 retaining structures, of which 228 are ranked as large dams that measure more than 15 metres high, 400 metres long and with a reservoir capacity of more than 1 million cubic metres of water. Hydro-Quebec addresses hydrological, seismic, technological and human risks through a dam safety procedure that includes structured plans for choosing best alternatives through staged exercises. Hazard levels are minimized through the adoption of emergency, prevention and alleviation measures. The utility

  13. Assessing Risks of Mine Tailing Dam Failures

    Science.gov (United States)

    Concha Larrauri, P.; Lall, U.

    2017-12-01

    The consequences of tailings dam failures can be catastrophic for communities and ecosystems in the vicinity of the dams. The failure of the Fundão tailings dam at the Samarco mine in 2015 killed 19 people with severe consequences for the environment. The financial and legal consequences of a tailings dam failure can also be significant for the mining companies. For the Fundão tailings dam, the company had to pay 6 billion dollars in fines and twenty-one executives were charged with qualified murder. There are tenths of thousands of active, inactive, and abandoned tailings dams in the world and there is a need to better understand the hazards posed by these structures to downstream populations and ecosystems. A challenge to assess the risks of tailings dams in a large scale is that many of them are not registered in publicly available databases and there is little information about their current physical state. Additionally, hazard classifications of tailings dams - common in many countries- tend to be subjective, include vague parameter definitions, and are not always updated over time. Here we present a simple methodology to assess and rank the exposure to tailings dams using ArcGIS that removes subjective interpretations. The method uses basic information such as current dam height, storage volume, topography, population, land use, and hydrological data. A hazard rating risk was developed to compare the potential extent of the damage across dams. This assessment provides a general overview of what in the vicinity of the tailings dams could be affected in case of a failure and a way to rank tailings dams that is directly linked to the exposure at any given time. One hundred tailings dams in Minas Gerais, Brazil were used for the test case. This ranking approach could inform the risk management strategy of the tailings dams within a company, and when disclosed, it could enable shareholders and the communities to make decisions on the risks they are taking.

  14. Research on Safety Factor of Dam Slope of High Embankment Dam under Seismic Condition

    Directory of Open Access Journals (Sweden)

    Li Bin

    2015-01-01

    Full Text Available With the constant development of construction technology of embankment dam, the constructed embankment dam becomes higher and higher, and the embankment dam with its height over 200m will always adopt the current design criteria of embankment dam only suitable for the construction of embankment dam lower than 200m in height. So the design criteria of high embankment dam shall be improved. We shall calculate the stability and safety factors of dam slope of high embankment dam under different dam height, slope ratio and different seismic intensity based on ratio of safety margin, and clarify the change rules of stability and safety factors of dam slope of high embankment dam with its height over 200m. We calculate the ratio of safety margin of traditional and reliable method by taking the stable, allowable and reliability index 4.2 of dam slope of high embankment dam with its height over 200m as the standard value, and conduct linear regression for both. As a result, the conditions, where 1.3 is considered as the stability and safety factors of dam slope of high embankment dam with its height over 200m under seismic condition and 4.2 as the allowable and reliability index, are under the same risk control level.

  15. Safety Evaluation Report related to the operation of Beaver Valley Power Station, Unit 2 (Docket No. 50-412)

    International Nuclear Information System (INIS)

    1985-10-01

    This Safety Evaluation Report on the application filed by Duquesne Light Company, as applicant and agent for the owners, for a license to operate the Beaver Valley Power Station Unit 2 (Docket No. 50-412) has been prepared by the Office of Nuclear Reactor Regulation of the US Nuclear Regulatory Commission. The facility is located in Shippingport Borough, Beaver County, Pennsylvania, on the south bank of the Ohio River. Subject to the favorable resolution of the items discussed in this report, the staff concludes that the facility can be operated by the applicant without endangering the health and safety of the public

  16. Habitat Evaluation Procedures (HEP) Report; West Beaver Lake Project, Technical Report 2005

    Energy Technology Data Exchange (ETDEWEB)

    Entz, Ray

    2005-05-01

    On September 7, 2004, the Habitat Evaluation Procedure (HEP) was used to determine baseline habitat suitability on the West Beaver Lake property, an acquisition completed by the Kalispel Tribe of Indians in September 2004. Evaluation species and appropriate models include bald eagle, black-capped chickadee, mallard, muskrat, and white-tailed deer. Habitat Suitability Index (HSI) values were visually estimated and agreed upon by all HEP team members. The West Beaver Lake Project provides a total of 82.69 Habitat Units (HUs) for the species evaluated. Emergent wetland habitat provides 8.80 HUs for mallard, muskrat, and Canada goose. Conifer forest habitat provides 70.33 HUs for bald eagle, black-capped chickadee, mallard, and white-tailed deer. Open water provides 3.30 HUs for mallard, muskrat, and Canada goose. The objective of using HEP at the West Beaver Lake Project and other protected properties is to document the quality and quantity of available habitat for selected wildlife species. In this way, HEP provides information on the relative value of the same area at future points in time so that the effect of management activities on wildlife habitat can be quantified. When combined with other tools, the baseline HEP will be used to determine the most effective on-site management, restoration, and enhancement actions to increase habitat suitability for targeted species. The same process will be replicated every five years to quantitatively evaluate the effectiveness of management strategies in improving and maintaining habitat conditions while providing additional crediting to BPA for enhanced habitat values.

  17. Maternal obesity disrupts circadian rhythms of clock and metabolic genes in the offspring heart and liver.

    Science.gov (United States)

    Wang, Danfeng; Chen, Siyu; Liu, Mei; Liu, Chang

    2015-06-01

    Early life nutritional adversity is tightly associated with the development of long-term metabolic disorders. Particularly, maternal obesity and high-fat diets cause high risk of obesity in the offspring. Those offspring are also prone to develop hyperinsulinemia, hepatic steatosis and cardiovascular diseases. However, the precise underlying mechanisms leading to these metabolic dysregulation in the offspring remain unclear. On the other hand, disruptions of diurnal circadian rhythms are known to impair metabolic homeostasis in various tissues including the heart and liver. Therefore, we investigated that whether maternal obesity perturbs the circadian expression rhythms of clock, metabolic and inflammatory genes in offspring heart and liver by using RT-qPCR and Western blotting analysis. Offspring from lean and obese dams were examined on postnatal day 17 and 35, when pups were nursed by their mothers or took food independently. On P17, genes examined in the heart either showed anti-phase oscillations (Cpt1b, Pparα, Per2) or had greater oscillation amplitudes (Bmal1, Tnf-α, Il-6). Such phase abnormalities of these genes were improved on P35, while defects in amplitudes still existed. In the liver of 17-day-old pups exposed to maternal obesity, the oscillation amplitudes of most rhythmic genes examined (except Bmal1) were strongly suppressed. On P35, the oscillations of circadian and inflammatory genes became more robust in the liver, while metabolic genes were still kept non-rhythmic. Maternal obesity also had a profound influence in the protein expression levels of examined genes in offspring heart and liver. Our observations indicate that the circadian clock undergoes nutritional programing, which may contribute to the alternations in energy metabolism associated with the development of metabolic disorders in early life and adulthood.

  18. Maternal obesity and high-fat diet program offspring metabolic syndrome.

    Science.gov (United States)

    Desai, Mina; Jellyman, Juanita K; Han, Guang; Beall, Marie; Lane, Robert H; Ross, Michael G

    2014-09-01

    We determined the potential programming effects of maternal obesity and high-fat (HF) diet during pregnancy and/or lactation on offspring metabolic syndrome. A rat model of maternal obesity was created using an HF diet prior to and throughout pregnancy and lactation. At birth, pups were cross-fostered, thereby generating 4 paradigms of maternal diets during pregnancy/lactation: (1) control (Con) diet during pregnancy and lactation (Con/Con), (2) HF during pregnancy and lactation (HF/HF), (3) HF during pregnancy alone (HF/Con), and (4) HF during lactation alone (Con/HF). Maternal phenotype during pregnancy and the end of lactation evidenced markedly elevated body fat and plasma corticosterone levels in HF dams. In the offspring, the maternal HF diet during pregnancy alone programmed increased offspring adiposity, although with normal body weight, whereas the maternal HF diet during lactation increased both body weight and adiposity. Metabolic disturbances, particularly that of hyperglycemia, were apparent in all groups exposed to the maternal HF diet (during pregnancy and/or lactation), although differences were apparent in the manifestation of insulin resistant vs insulin-deficient phenotypes. Elevated systolic blood pressure was manifest in all groups, implying that exposure to an obese/HF environment is disadvantageous for offspring health, regardless of pregnancy or lactation periods. Nonetheless, the underlying mechanism may differ because offspring that experienced in utero HF exposure had increased corticosterone levels. Maternal obesity/HF diet has a marked impact on offspring body composition and the risk of metabolic syndrome was dependent on the period of exposure during pregnancy and/or lactation. Copyright © 2014 Mosby, Inc. All rights reserved.

  19. Offspring of prenatal IV nicotine exposure exhibit increased sensitivity to the reinforcing effects of methamphetamine

    Directory of Open Access Journals (Sweden)

    Steven Brown Harrod

    2012-06-01

    Full Text Available Maternal smoking during pregnancy is associated with increased substance abuse in offspring. Preclinical research shows that in utero exposure to nicotine, the primary psychoactive compound in tobacco smoke, influences the neurodevelopment of reward systems and alters motivated behavior in offspring. The present study determined if prenatal nicotine (PN exposure altered the sensitivity to the reinforcing and aversive effects of methamphetamine (METH in offspring using a low dose, intravenous (IV exposure method. Pregnant dams were administered nicotine (0.05 mg/kg/injection or prenatal saline (PS 3×/day on gestational days 8-21, and adult offspring were tested using METH self-administration (experiment 1 or METH-induced conditioned taste aversion (CTA; experiment 2 procedures. For METH self-administration, animals were trained to respond for IV METH (0.05 mg/kg/injection; fixed-ratio 3 and they were tested on varying doses the reinforcer (0.0005-1.0 mg/kg/injection. For METH CTA, rats received three saccharin and METH pairings (0, 0.3, or 0.5 mg/kg, sc followed by fourteen daily extinction trials. Experiment 1: PN and PS animals exhibited inverted U-shaped dose-response curves; however, the PN animal’s curve was shifted to the left, suggesting PN animals were more sensitive to the reinforcing effects of METH. Experiment 2: METH CTA was acquired in a dose-dependent manner and the factor of PN exposure was not related to the acquisition or extinction of METH-induced CTA. There were no sex differences in either experiment. These results indicate that adult offspring of IV PN exposure exhibited altered motivation for the reinforcing effects of METH. This suggests that PN exposure, via maternal smoking, will alter the reinforcing effects of METH during later stages of development, and furthermore, will influence substance use vulnerability in adult human offspring.

  20. Fracture toughness master curve characterization of Linde 1092 weld metal for Beaver valley 1 reactor

    International Nuclear Information System (INIS)

    Lee, Bong Sang; Yang, Won Jon; Hong, Jun Hwa

    2000-12-01

    This report summarizes the test results obtained from the Korean contribution to the integrity assessment of low toughness Beaver Valley reactor vessel by characterizing the fracture toughness of Linde 1092 (No. 305414) weld metal. 10 PCVN specimens and 10 1T-CT specimens were tested in accordance with the ASTM E 1921-97 standard, 'Standard test method for determination of reference temperature, T o , for ferritic steels in the transition range'. This results can also be useful for assessment of Linde 80 low toughness welds of Kori-1

  1. Fracture toughness master curve characterization of Linde 1092 weld metal for Beaver valley 1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bong Sang; Yang, Won Jon; Hong, Jun Hwa

    2000-12-01

    This report summarizes the test results obtained from the Korean contribution to the integrity assessment of low toughness Beaver Valley reactor vessel by characterizing the fracture toughness of Linde 1092 (No. 305414) weld metal. 10 PCVN specimens and 10 1T-CT specimens were tested in accordance with the ASTM E 1921-97 standard, 'Standard test method for determination of reference temperature, T{sub o}, for ferritic steels in the transition range'. This results can also be useful for assessment of Linde 80 low toughness welds of Kori-1.

  2. Constituent concentrations, loads, and yields to Beaver Lake, Arkansas, water years 1999-2008

    Science.gov (United States)

    Bolyard, Susan E.; De Lanois, Jeanne L.; Green, W. Reed

    2010-01-01

    Beaver Lake is a large, deep-storage reservoir used as a drinking-water supply and considered a primary watershed of concern in the State of Arkansas. As such, information is needed to assess water quality, especially nutrient enrichment, nutrient-algal relations, turbidity, and sediment issues within the reservoir system. Water-quality samples were collected at three main inflows to Beaver Lake: the White River near Fayetteville, Richland Creek at Goshen, and War Eagle Creek near Hindsville. Water-quality samples collected over the period represented different flow conditions (from low to high). Constituent concentrations, flow-weighted concentrations, loads, and yields from White River, Richland Creek, and War Eagle Creek to Beaver Lake for water years 1999-2008 were documented for this report. Constituents include total ammonia plus organic nitrogen, dissolved nitrite plus nitrate nitrogen, dissolved orthophosphorus (soluble reactive phosphorus), total phosphorus, total nitrogen, dissolved organic carbon, total organic carbon, and suspended sediment. Linear regression models developed by computer program S-LOADEST were used to estimate loads for each constituent for the 10-year period at each station. Constituent yields and flow-weighted concentrations for each of the three stations were calculated for the study. Constituent concentrations and loads and yields varied with time and varied among the three tributaries contributing to Beaver Lake. These differences can result from differences in precipitation, land use, contributions of nutrients from point sources, and variations in basin size. Load and yield estimates varied yearly during the study period, water years 1999-2008, with the least nutrient and sediment load and yields generally occurring in water year 2006, and the greatest occurring in water year 2008, during a year with record amounts of precipitation. Flow-weighted concentrations of most constituents were greatest at War Eagle Creek near Hindsville

  3. Magnetohydrodynamic boundary layer flow past a porous substrate with Beavers-Joseph boundary condition

    International Nuclear Information System (INIS)

    Jat, R.N.; Chaudhary, Santosh

    2009-01-01

    The flow of an electrically conducting fluid past a porous substrate attached to the flat plate with Beavers-Joseph boundary condition under the influence of a uniform transverse magnetic field has been studied. Taking suitable similar variables, the momentum equation is transformed to ordinary differential equation and solved by standard techniques. The energy equation is solved by considering two boundary layers, one in the porous substrate and the other above the porous substrate. The velocity and temperature distributions along with Nusselt number are discussed numerically and presented through graphs. (author)

  4. New guidelines for dam safety classification

    International Nuclear Information System (INIS)

    Dascal, O.

    1999-01-01

    Elements are outlined of recommended new guidelines for safety classification of dams. Arguments are provided for the view that dam classification systems should require more than one system as follows: (a) classification for selection of design criteria, operation procedures and emergency measures plans, based on potential consequences of a dam failure - the hazard classification of water retaining structures; (b) classification for establishment of surveillance activities and for safety evaluation of dams, based on the probability and consequences of failure - the risk classification of water retaining structures; and (c) classification for establishment of water management plans, for safety evaluation of the entire project, for preparation of emergency measures plans, for definition of the frequency and extent of maintenance operations, and for evaluation of changes and modifications required - the hazard classification of the project. The hazard classification of the dam considers, as consequence, mainly the loss of lives or persons in jeopardy and the property damages to third parties. Difficulties in determining the risk classification of the dam lie in the fact that no tool exists to evaluate the probability of the dam's failure. To overcome this, the probability of failure can be substituted for by a set of dam characteristics that express the failure potential of the dam and its foundation. The hazard classification of the entire project is based on the probable consequences of dam failure influencing: loss of life, persons in jeopardy, property and environmental damage. The classification scheme is illustrated for dam threatening events such as earthquakes and floods. 17 refs., 5 tabs

  5. Parental Exposure to Dim Light at Night Prior to Mating Alters Offspring Adaptive Immunity.

    Science.gov (United States)

    Cissé, Yasmine M; Russart, Kathryn L G; Nelson, Randy J

    2017-03-31

    Exposure to dim light at night (dLAN) disrupts natural light/dark cycles and impairs endogenous circadian rhythms necessary to maintain optimal biological function, including the endocrine and immune systems. We have previously demonstrated that white dLAN compromises innate and cell mediated immune responses in adult Siberian hamsters (Phodopus sungorus). We hypothesized that dLAN has transgenerational influences on immune function. Adult male and female Siberian hamsters were exposed to either dark nights (DARK) or dLAN (~5 lux) for 9 weeks, then paired in full factorial design, mated, and thereafter housed under dark nights. Offspring were gestated and reared in dark nights, then tested as adults for cell-mediated and humoral immunity. Maternal exposure to dLAN dampened delayed type hypersensitivity (DTH) responses in male offspring. Maternal and paternal exposure to dLAN reduced DTH responses in female offspring. IgG antibodies to a novel antigen were elevated in offspring of dams exposed to dLAN. Paternal exposure to dLAN decreased splenic endocrine receptor expression and global methylation in a parental sex-specific manner. Together, these data suggest that exposure to dLAN has transgenerational effects on endocrine-immune function that may be mediated by global alterations in the epigenetic landscape of immune tissues.

  6. Effect of Perinatal Lead Exposure on the Social Behaviour of Laboratory Mice Offspring at Adolescent Age

    International Nuclear Information System (INIS)

    AbuTaweel Qasim M; Ajarem Jamaan S

    2008-01-01

    Lead ( Pb ) was given to Swiss-Webster female mice at the concentrations of 0.1 and 0.2% ( w/v ) , containing 550 and 1100 ppm of lead respectively, in their drinking water. Treatment started from day 1 of pregnancy until day 15 postnatally . Thereafter, the dams were switched to plain tap water. After the weaning period ( 21 days ), all male offspring were isolated (one animal per cage) for 14 days, and the isolated male offspring were subjected to 'Standard Opponenttest' at the age of 36 days . the results of this test showed a significant and dose-dependent increase in the non-social behaviour , whereas such results showed a significant decline in the social behaviour including naso-genital and naso-nasal contact, number of fights, rear, wall rear and displacement activities of the Pb exposed young adult male offspring. The present perinatal Pb effects in the male offspring are possibly via in utero exposure and/or via mother's milk. (author)

  7. The effects of prenatal exposure to a 'junk food' diet on offspring food preferences and fat deposition can be mitigated by improved nutrition during lactation.

    Science.gov (United States)

    Gugusheff, J R; Vithayathil, M; Ong, Z Y; Muhlhausler, B S

    2013-10-01

    Exposure to a maternal junk food (JF) diet in utero and during the suckling period has been demonstrated to increase the preference for palatable food and increase the susceptibility to diet-induced obesity in adult offspring. We aimed to determine whether the effects of prenatal exposure to JF could be ameliorated by cross-fostering offspring onto dams consuming a standard rodent chow during the suckling period. We report here that when all offspring were given free access to the JF diet for 7 weeks from 10 weeks of age, male offspring of control (C) or JF dams that were cross-fostered at birth onto JF dams (C-JF, JF-JF), exhibited higher fat (C-C: 12.3 ± 0.34 g/kg/day; C-JF: 14.7 ± 1.04 g/kg/day; JF-C: 11.5 ± 0.41 g/kg/day; JF-JF: 14.0 ± 0.44 g/kg/day; P food intake, had increased fat mass as percentage of body weight (C-C: 19.9 ± 1.33%; C-JF: 22.8 ± 1.57%; JF-C: 17.4 ± 1.03%; JF-JF: 22.0 ± 1.0%; P food preferences in females and susceptibility to diet-induced obesity in males can be prevented by improved nutrition during the suckling period.

  8. Research on shape optimization of CSG dams

    Directory of Open Access Journals (Sweden)

    Xin Cai

    2011-12-01

    Full Text Available The multi-objective optimization method was used for shape optimization of cement sand and gravel (CSG dams in this study. The economic efficiency, the sensitivities of maximum horizontal displacement and maximum settlement of the dam to water level changes, the overall stability, and the overall strength security were taken into account during the optimization process. Three weight coefficient selection schemes were adopted to conduct shape optimization of a dam, and the case studies lead to the conclusion that both the upstream and downstream dam slope ratios for the optimal cross-section equal 1:0.7, which is consistent with the empirically observed range of 1:0.6 to 1:0.8 for the upstream and downstream dam slope ratios of CSG dams. Therefore, the present study is of certain reference value for designing CSG dams.

  9. Dynamic tests at the Outardes 3 dam

    International Nuclear Information System (INIS)

    Proulx, J.; Paultre, P.; Duron, Z.; Tai Mai Phat; Im, O.

    1992-01-01

    At the Outardes 3 gravity dam, part of the Manicouagan-Outardes hydroelectric complex in northeastern Quebec, forced vibration tests were carried out using an eccentric mass shaker attached to the dam crest at three different locations. Accelerations were measured along the crest and in the inspection galleries, and hydrodynamic pressures were measured along the upstream dam face and at various locations in the reservoir. The tests were designed to analyze the effects of gravity dam-reservoir interactions and to generate a data base for calibrating finite element models used in studying the dynamic behavior of gravity dams. Experimental results are presented in order to demonstrate the quality of the data obtained and the effectiveness of the experimental procedures. Modes of vibration were observed which corresponded to those obtained by finite element analysis. It is shown that techniques recently developed for dynamic tests on large dams can be successfully used on gravity dams. 3 refs., 6 figs

  10. Offspring sex and parental health and mortality

    DEFF Research Database (Denmark)

    Næss, Øyvind; Mortensen, Laust H.; Vikanes, Åse

    2017-01-01

    ) number of total boy and girl offspring, 2) sex of the first and second offspring and 3) proportion of boys to total number of offspring. A sub-cohort (n = 50,736 mothers, n = 44,794 fathers) from survey data was analysed for risk factors. Mothers had increased risk of total and cardiovascular mortality...... that was consistent across approaches: cardiovascular mortality of 1.07 (95% CI: 1.03-1.11) per boy (approach 2), 1.04 (1.01-1.07) if the first offspring was a boy, and 1.06 (1.01-1.10) if the first two offspring were boys (approach 3). We found that sex of offspring was not associated with total or cardiovascular...

  11. Developmental fluoxetine exposure increases behavioral despair and alters epigenetic regulation of the hippocampal BDNF gene in adult female offspring.

    Science.gov (United States)

    Boulle, Fabien; Pawluski, Jodi L; Homberg, Judith R; Machiels, Barbie; Kroeze, Yvet; Kumar, Neha; Steinbusch, Harry W M; Kenis, Gunter; van den Hove, Daniel L A

    2016-04-01

    A growing number of infants are exposed to selective serotonin reuptake inhibitor (SSRI) medications during the perinatal period. Perinatal exposure to SSRI medications alter neuroplasticity and increase depressive- and anxiety-related behaviors, particularly in male offspring as little work has been done in female offspring to date. The long-term effects of SSRI on development can also differ with previous exposure to prenatal stress, a model of maternal depression. Because of the limited work done on the role of developmental SSRI exposure on neurobehavioral outcomes in female offspring, the aim of the present study was to investigate how developmental fluoxetine exposure affects anxiety and depression-like behavior, as well as the regulation of hippocampal brain-derived neurotrophic factor (BDNF) signaling in the hippocampus of adult female offspring. To do this female Sprague-Dawley rat offspring were exposed to prenatal stress and fluoxetine via the dam, for a total of four groups of female offspring: 1) No Stress+Vehicle, 2) No Stress+Fluoxetine, 3) Prenatal Stress+Vehicle, and 4) Prenatal Stress+Fluoxetine. Primary results show that, in adult female offspring, developmental SSRI exposure significantly increases behavioral despair measures on the forced swim test, decreases hippocampal BDNF exon IV mRNA levels, and increases levels of the repressive histone 3 lysine 27 tri-methylated mark at the corresponding promoter. There was also a significant negative correlation between hippocampal BDNF exon IV mRNA levels and immobility in the forced swim test. No effects of prenatal stress or developmental fluoxetine exposure were seen on tests of anxiety-like behavior. This research provides important evidence for the long-term programming effects of early-life exposure to SSRIs on female offspring, particularily with regard to affect-related behaviors and their underlying molecular mechanisms. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Proceedings of the 2010 Canadian Dam Association's public safety around dams workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Nearly 30 people have drowned in dam-related incidents over the last 10 years in Canada. The Canadian public is now calling for improved safety guidelines. Public interaction with dams is increasing as a result of interest in extreme sports and perceived rights of access. However, many members of the public are not aware of the dangers posed by dams. This workshop provided a forum to discuss proposals for a draft publication of the Canadian Dam Association (CDA) guidelines for public safety and security around dams. Issues related to current legislation and liability were discussed. Methods of increasing public awareness of the hazards posed by dams included increased signage in dam locations, the use of audible and visual alert systems, and the use of booms and buoys. The responsibilities of dam owners in ensuring the safety of dams were also discussed. The conference featured 5 presentations, of which 2 have been catalogued separately for inclusion in this database. tabs., figs.

  13. Study of Dam-break Due to Overtopping of Four Small Dams in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Zakaraya Alhasan

    2015-01-01

    Full Text Available Dam-break due to overtopping is one of the most common types of embankment dam failures. During the floods in August 2002 in the Czech Republic, several small dams collapsed due to overtopping. In this paper, an analysis of the dam break process at the Luh, Velký Bělčický, Melín, and Metelský dams breached during the 2002 flood is presented. Comprehensive identification and analysis of the dam shape, properties of dam material and failure scenarios were carried out after the flood event to assemble data for the calibration of a numerical dam break model. A simple one-dimensional mathematical model was proposed for use in dam breach simulation, and a computer code was compiled. The model was calibrated using the field data mentioned above. Comparison of the erodibility parameters gained from the model showed reasonable agreement with the results of other authors.

  14. Management of dams for the next Millennium: proceedings of the 1999 Canadian Dam Association

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    The meeting featured seven sessions with 18 papers abstracted/indexed therein as follows: keynote address: tailings dams safety - implications for the dam safety community; 1 - design and performance: performance monitoring of dams: are we doing what we should be doing?; tailings dams from the perspective of conventional dam engineering; and design overview of Syncrude's Mildred Lake east toe berm; 2 - design and modelling: use of a 2D model for a dam break study on the ALCAN hydroelectric complex in Quebec; and spillway design implications resulting from changes in rainfall extremes; 3 - risk and dam safety I: closing the gaps in the dam safety guidelines; the reality of life safety consequence classification; and surveillance practices for the next millenium; 4 - risk and dam safety II: quantitative risk-assessment using the capacity-demand analysis; and new guidelines for dam safety classification; 5 - millenium issues: expectations of immortality, dam safety management into the next millenium; 6 - rehabilitation techniques: the unconventional application of conventional materials; nondestructive testing technology to characterize concrete dam/bedrock interface; method and instrument for detecting crack in concrete; and grouting of the cracks in the Arch 5-6 - Daniel Johnson Dam; and 7 - case studies: rehabilitation of an 80 year old Ambursen type dam; and debris booms for the protection of spillways.

  15. The offspring of epileptic mother.

    Science.gov (United States)

    Tamer, S K; Misra, S; Jaiswal, S

    1996-01-01

    The offspring of an epileptic mother is an issue-currently getting attention because of its several implications. A complex interaction between epilepsy during pregnancy and its adverse impact on foetus, labor, neonate, congenital malformation, psychosocial and medico-social concern and treatment challenges of such cases is increasingly being realised. Some of the significant observations has been reviewed extensively in this article. Maternal epilepsy is likely to adversely affect the off-spring at its various stages of development amounting to increased morbidity and mortality. Increased seizure frequency during pregnancy with resultant increased risk is well documented but its mechanism is poorly understood. Low apgar score, increased still birth rates (1.3 to 14%) in offspring of epileptic mother (OEM) is reported. So also, the neonatal and perinatal deaths are twice more common in OEMS than normal control. Small for dates, and prematurity in OEM is reported to be 7 to 10% and 4-11% respectively. Adverse impact on labor and delivery like preclampsia, abruptio placentae, polyhydramnios, assisted delivery, cesarean section and IUGR poses particular challenges to the obstetrician. Pediatrician's alertness is needed to anticipate and deal with the bleeding manifestation due to deficiency of Vit-K dependent clotting factors and various anticonvulsant drug (AED) withdrawal symptoms. Significant risk of developing congenital malformation is the result of epilepsy perse and the AED used during pregnancy. AED exposure leads to other distinct clinical syndromes, the orofacial clefts and cardiac anomalies being the commonest manifestation. Epilepsy in mother but not in father has significant adverse impact. Management strategies in the context of available observation has been discussed.

  16. Crotch Lake dam rehabilitation project

    International Nuclear Information System (INIS)

    Brunet, G.; Dobrowolski, E.

    1999-01-01

    Replacement of the existing wood crib dam structure on Crotch Lake on the Mississippi River in eastern Ontario that provided water storage for the power production at High Falls Generating Station, became necessary when it was determined that the dam did not meet Ontario-Hydro's safety standards. This paper describes the project of replacing the existing structure with a PVC coated gabion wall with waterproofing. The entire structure was covered with three layers of wire mesh, laced together, and criss-crossed for superior strength and rigidity. The work was completed in 28 days with no environmental impact . Life expectancy of the new structure is in excess of 40 years. With periodic maintenance of the gabion mat cover, life span could be extended an additional 20 to 40 years. 5 figs

  17. Morphology of an Early Oligocene beaver Propalaeocastor irtyshensis and the status of the genus Propalaeocastor

    Directory of Open Access Journals (Sweden)

    Lüzhou Li

    2017-05-01

    Full Text Available The Early to Late Oligocene Propalaeocastor is the earliest known beaver genus from Eurasia. Although many species of this genus have been described, these species are defined based on very fragmentary specimens. Propalaeocastor irtyshensis from the Early Oligocene Irtysh River Formation in northwestern Xinjiang, China is one of the earliest-known members of Propalaeocastor. This species is defined on a single maxillary fragment. We revise the diagnosis of P. irtyshensis and the genus Propalaeocastor, based on newly discovered specimens from the Irtysh River Formation. The dental morphology of P. irtyshensis is very similar to other early castorids. The caudal palatine foramen of P. irtyshensis is situated in the maxillary-palatine suture. This is a feature generally accept as diagnostic character for the castorids. On the other hand, P. irtyshensis has two upper premolars, a rudimentarily developed sciuromorph-like zygomatic plate, and a relatively large protrogomorph-like infraorbital foramen. Some previous researchers suggested that Propalaeocastor is a junior synonym of Steneofiber, while other took it as a valid genus. Our morphological comparison and phylogenetic analysis suggest that Propalaeocastor differs from Steneofiber and is a valid genus. We also suggest that Agnotocastor aubekerovi, A. coloradensis, A. galushai, A. readingi, Oligotheriomys primus, and “Steneofiber aff. dehmi” should be referred to Propalaeocastor. Propalaeocastor is the earliest and most basal beaver. The origin place of Propalaeocastor and castorids is uncertain. The Early Oligocene radiation of castorids probably is propelled by the global climate change during the Eocene-Oligocene transition.

  18. The effect of beaver ponds on water quality in rural coastal plain streams

    Science.gov (United States)

    Bason, Christopher W.; Kroes, Daniel; Brinson, Mark M.

    2017-01-01

    We compared water-quality effects of 13 beaver ponds on adjacent free-flowing control reaches in the Coastal Plain of rural North Carolina. We measured concentrations of nitrate, ammonium, soluble reactive phosphorus (SRP), and suspended sediment (SS) upstream and downstream of paired ponds and control reaches. Nitrate and SS concentrations decreased, ammonium concentrations increased, and SRP concentrations were unaffected downstream of the ponds and relative to the control reaches. The pond effect on nitrate concentration was a reduction of 112 ± 55 μg-N/L (19%) compared to a control-reach—influenced reduction of 28 ± 17 μg-N/L. The pond effect on ammonium concentration was an increase of 9.47 ± 10.9 μg-N/L (59%) compared to the control-reach—influenced reduction of 1.49 ± 1.37 μg-N/L. The pond effect on SS concentration was a decrease of 3.41 ± 1.68 mg/L (40%) compared to a control-reach—influenced increase of 0.56 ± 0.27 mg/L. Ponds on lower-order streams reduced nitrate concentrations by greater amounts compared to those in higher-order streams. Older ponds reduced SS concentrations by greater amounts compared to younger ponds. The findings of this study indicate that beaver ponds provide water-quality benefits to rural Coastal Plain streams by reducing concentrations of nitrate and suspended sediment.

  19. Coupled models in dam engineering

    OpenAIRE

    González Gutiérrez, María De Los Ángeles

    2016-01-01

    Rock ll dams are certainly one of the most important engineering structures due to their economic advantages and exible design. Unfortunately their vulnerability to overtopping still remains their weakest point. For that reason, several research groups are interested in both the numerical and experimental analysis of this phenomenon. In this work we focused on the numerical analysis. The previous work developed in CIMNE on a coupled PFEM-Eulerian free surface Compu- tational...

  20. Environmental monitoring at Olympic Dam

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    The environmental management and protection program at the Olympic Dam uranium/copper/gold project, Roxby Downs, South Australia, monitors eight major environmental parameters - meteorology, vegetation, mine site rehabilitation, fauna, terrain, soil salinity, hydrogeology and well fields. It came into effect with the approval of the South Australian Government in March 1987. The Great Artesian Basin, one of the world's greatest artesian basins, is the source of the water supply for the project

  1. Mitigating Dam Impacts Using Environmental Flow Releases

    Science.gov (United States)

    Richter, B. D.

    2017-12-01

    One of the most ecologically disruptive impacts of dams is their alteration of natural river flow variability. Opportunities exist for modifying the operations of existing dams to recover many of the environmental and social benefits of healthy ecosystems that have been compromised by present modes of dam operation. The potential benefits of dam "re-operation" include recovery of fish, shellfish, and other wildlife populations valued both commercially and recreationally, including estuarine species; reactivation of the flood storage and water purification benefits that occur when floods are allowed to flow into floodplain forests and wetlands; regaining some semblance of the naturally dynamic balance between river erosion and sedimentation that shapes physical habitat complexity, and arresting problems associated with geomorphic imbalances; cultural and spiritual uses of rivers; and many other socially valued products and services. Assessing the potential benefits of dam re-operation begins by characterizing the dam's effects on the river flow regime, and formulating hypotheses about the ecological and social benefits that might be restored by releasing water from the dam in a manner that more closely resembles natural flow patterns. These hypotheses can be tested by implementing a re-operation plan, tracking the response of the ecosystem, and continually refining dam operations through adaptive management. This presentation will highlight a number of land and water management strategies useful in implementing a dam re-operation plan, with reference to a variety of management contexts ranging from individual dams to cascades of dams along a river to regional energy grids. Because many of the suggested strategies for dam re-operation are predicated on changes in the end-use of the water, such as reductions in urban or agricultural water use during droughts, a systemic perspective of entire water management systems will be required to attain the fullest possible

  2. Reconnaissance investigation of high-calcium marble in the Beaver Creek area, St. Lawrence County, New York

    Science.gov (United States)

    Brown, C. Ervin

    1978-01-01

    Three belts of marble of the Grenville Series were mapped in the Beaver Creek drainage basin, St. Lawrence County, N.Y. One of these, on the west side of Beaver Creek, consists of coarsely crystalline pure calcitic marble that occurs in a zone at least 10 by 0.8 km in extent. Samples of marble show CaCO3 content to be greater than 93 percent, and some samples contain greater than 96 percent, and only small amounts of MgO and Fe203 are present. Marble in two other belts to the east of Beaver Creek are variable in composition, but locally have high content of calcium carbonate material. The marble deposit west of Beaver Creek has a chemical composition favorable for specialized chemical, industrial, and metallurgical uses. Another favorable aspect of the deposit is its proximity to inexpensive water transportation on the St. Lawrence Seaway only 27.5 km away by road, at Ogdensburg, N.Y.

  3. Draft Environmental Statement related to the operation of Beaver Valley Power Station, Unit 2 (Docket No. 50-412)

    International Nuclear Information System (INIS)

    1984-12-01

    This Draft Environmental Statement contains the second assessment of the environmental impact associated with Beaver Valley Power Station Unit 2 pursuant to the National Environmental Policy Act of 1969 (NEPA) and Title 10 of the Code of Federal Regulations, Part 51, as amended, of the Nuclear Regulatory Commission regulations. This statement examines the environment, environmental consequences and mitigating actions, and environmental benefits and costs

  4. Conformance to Regulatory Guide 1.97, Beaver Valley Power Station, Unit No. 2 (Docket No. 50-412)

    International Nuclear Information System (INIS)

    Stoffel, J.W.; Udy, A.C.

    1985-11-01

    This EG and G Idaho, Inc., report reviews the submittals for Regulatory Guide 1.97 for Unit No. 2 of the Beaver Valley Power Station and identifies areas of nonconformance to the regulatory guide. Exceptions to Regulatory Guide 1.97 are evaluated and those areas where sufficient basis for acceptability is not provided are identified

  5. Leave It to Beaver. Merchants Millpond State Park: An Environmental Education Learning Experience Designed for Grades 4-6.

    Science.gov (United States)

    Williams, Floyd K.

    This learning packet, one in a group of eight, was developed by the Merchants Millpond State Park in North Carolina to teach students in grades 4-6 about the habitat and lifestyle of the beaver. Loose-leaf pages are presented in nine sections that contain: (1) introductions to the North Carolina State Parks System, the Merchants Millpond State…

  6. The Relationship between Market and Accounting Determined Risk Measures: Reviewing and Updating the Beaver, Kettler, Scholes (1970) Study

    Science.gov (United States)

    Jarvela, Michael; Kozyra, James; Potter, Carla

    2009-01-01

    The association between market-determined risk measures and accounting-determined risk measures was originally explored in the 1970s by Beaver, Kettler, and Scholes (BKS). The results of the BKS (1970) study suggest that accounting information is usefulness in assessing firm specific risk. Since BKS, there have been few studies conducted to…

  7. Exposure of maternal mice to cis-bifenthrin enantioselectively disrupts the transcription of genes related to testosterone synthesis in male offspring.

    Science.gov (United States)

    Jin, Yuanxiang; Wang, Jiangcong; Sun, Xueqing; Ye, Yang; Xu, Minjie; Wang, Jianai; Chen, Shaoping; Fu, Zhengwei

    2013-12-01

    The commercial bifenthrin (BF) contains two cis isomers. In the present study, a dose of 15mg/kg of 1R-cis-BF or 1S-cis-BF was orally administered for 3 weeks to female mice before or during pregnancy. Then, the expression of steroidogenesis related genes which were considered as effective biomarkers of endocrine disruption were analyzed in the male offspring. Maternal exposure to 1S-cis-BF during pregnancy significantly reduced the mRNA levels of peripheral benzodiazepine receptor (PBR) and steroidogenic acute regulatory protein (StAR) in the testes of 3- or 6-week old male offspring. In addition, a significant decrease of cytochrome P450 17α-hydroxysteroid dehydrogenase (P450-17α) was also observed in the testes of 6-week old male offspring when dams were treated with 1S-cis-BF during pregnancy but not before pregnancy. Moreover, the scavenger receptor class B type 1 (SRB1) and cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc) decreased significantly in the testes of 6-week old male offspring when dams were treated with 1S-cis-BF during and before pregnancy. Thus, oral administration of the maternal mice to cis-BF for 3 weeks, particularly during pregnancy, resulted in endocrine disruption in the male offspring, with the 1S-cis-BF causing more significant alterations than the 1R-cis-BF form. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Methyl vitamins contribute to obesogenic effects of a high multivitamin gestational diet and epigenetic alterations in hypothalamic feeding pathways in Wistar rat offspring.

    Science.gov (United States)

    Cho, Clara E; Pannia, Emanuela; Huot, Pedro S P; Sánchez-Hernández, Diana; Kubant, Ruslan; Dodington, David W; Ward, Wendy E; Bazinet, Richard P; Anderson, G Harvey

    2015-03-01

    High multivitamin (HV, tenfold AIN-93G) gestational diets fed to Wistar rats increase food intake, obesity, and characteristics of metabolic syndrome in the offspring. We hypothesized that methyl vitamins, and specifically folate, in the HV gestational diet contribute to the obesogenic phenotypes consistent with their epigenetic effects on hypothalamic food intake regulatory mechanisms. Male offspring of dams fed the AIN-93G diet with high methyl vitamins (HMethyl; tenfold folate, vitamins B12, and B6) (Study 1) and HV with recommended folate (HVRF) (Study 2) were compared with those from HV and recommended vitamin (RV) fed dams. All offspring were weaned to a high fat diet for 8 wks. HMethyl diet, similar to HV, and compared to RV, resulted in higher food intake, body weight, and metabolic disturbances. Removing folate additions to the HV diet in HVRF offspring normalized the obesogenic phenotype. Methyl vitamins, and folate in HV diets, altered hypothalamic gene expression toward increased food intake concurrent with DNA methylation and leptin and insulin receptor signaling dysfunction. Methyl vitamins in HV gestational diets contribute to obesogenic phenotypes and epigenetic alterations in the hypothalamic feeding pathways in the offspring. Folate alone accounts for many of these effects. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Maternal High Folic Acid Supplement Promotes Glucose Intolerance and Insulin Resistance in Male Mouse Offspring Fed a High-Fat Diet

    Directory of Open Access Journals (Sweden)

    Yifan Huang

    2014-04-01

    Full Text Available Maternal nutrition may influence metabolic profiles in offspring. We aimed to investigate the effect of maternal folic acid supplement on glucose metabolism in mouse offspring fed a high-fat diet (HFD. Sixty C57BL/6 female mice were randomly assigned into three dietary groups and fed the AIN-93G diet containing 2 (control, 5 (recommended folic acid supplement, RFolS or 40 (high folic acid supplement, HFolS mg folic acid/kg of diet. All male offspring were fed HFD for eight weeks. Physiological, biochemical and genetic variables were measured. Before HFD feeding, developmental variables and metabolic profiles were comparable among each offspring group. However, after eight weeks of HFD feeding, the offspring of HFolS dams (Off-HFolS were more vulnerable to suffer from obesity (p = 0.009, glucose intolerance (p < 0.001 and insulin resistance (p < 0.001, compared with the controls. Off-HFolS had reduced serum adiponectin concentration, accompanied with decreased adiponectin mRNA level but increased global DNA methylation level in white adipose tissue. In conclusion, our results suggest maternal HFolS exacerbates the detrimental effect of HFD on glucose intolerance and insulin resistance in male offspring, implying that HFolS during pregnancy should be adopted cautiously in the general population of pregnant women to avoid potential deleterious effect on the metabolic diseases in their offspring.

  10. The effects of feeding rats diets deficient in folic acid and related methyl donors on the blood pressure and glucose tolerance of the offspring.

    Science.gov (United States)

    Maloney, Christopher A; Hay, Susan M; Rees, William D

    2009-05-01

    In humans poor maternal folate status is associated with a decrease in infant birth weight. As low birth weight increases the risk of cardiovascular and metabolic disease in adults, an inadequate supply of folic acid in the mother's diet may increase the susceptibility of the offspring to disease. We have fed laboratory rats diets deficient in folic acid and the related methyl donors methionine and choline to examine the effects on growth, blood pressure and insulin action in the offspring. Poor folate status transiently increased fetal growth but did not produce a long-term change in body weight. There were, however, small changes in the hearts of the female offspring. When folate deficiency was combined with low intakes of methionine and choline, the kidneys of the male offspring were proportionately smaller, probably because of the limited availability of methionine. There was no effect on the blood pressure of either the male or female offspring. The pancreatic insulin content of fetuses from animals fed the folate-deficient diets were higher than those of the controls. Following an oral glucose challenge, there was a weak trend for glucose-stimulated insulin release to be increased in the offspring of dams fed the folate-deficient diet. The changes in insulin concentrations were, however, much smaller than the corresponding changes observed in the offspring of animals fed protein-deficient diets. These results suggest that folate deficiency during gestation causes modest changes to the insulin axis of the fetus.

  11. Chronic Maternal Low-Protein Diet in Mice Affects Anxiety, Night-Time Energy Expenditure and Sleep Patterns, but Not Circadian Rhythm in Male Offspring.

    Directory of Open Access Journals (Sweden)

    Randy F Crossland

    Full Text Available Offspring of murine dams chronically fed a protein-restricted diet have an increased risk for metabolic and neurobehavioral disorders. Previously we showed that adult offspring, developmentally exposed to a chronic maternal low-protein (MLP diet, had lower body and hind-leg muscle weights and decreased liver enzyme serum levels. We conducted energy expenditure, neurobehavioral and circadian rhythm assays in male offspring to examine mechanisms for the body-weight phenotype and assess neurodevelopmental implications of MLP exposure. C57BL/6J dams were fed a protein restricted (8%protein, MLP or a control protein (20% protein, C diet from four weeks before mating until weaning of offspring. Male offspring were weaned to standard rodent diet (20% protein and single-housed until 8-12 weeks of age. We examined body composition, food intake, energy expenditure, spontaneous rearing activity and sleep patterns and performed behavioral assays for anxiety (open field activity, elevated plus maze [EPM], light/dark exploration, depression (tail suspension and forced swim test, sociability (three-chamber, repetitive (marble burying, learning and memory (fear conditioning, and circadian behavior (wheel-running activity during light-dark and constant dark cycles. We also measured circadian gene expression in hypothalamus and liver at different Zeitgeber times (ZT. Male offspring from separate MLP exposed dams had significantly greater body fat (P = 0.03, less energy expenditure (P = 0.004, less rearing activity (P = 0.04 and a greater number of night-time rest/sleep bouts (P = 0.03 compared to control. MLP offspring displayed greater anxiety-like behavior in the EPM (P<0.01 but had no learning and memory deficit in fear-conditioning assay (P = 0.02. There was an effect of time on Per1, Per 2 and Clock circadian gene expression in the hypothalamus but not on circadian behavior. Thus, transplacental and early developmental exposure of dams to chronic MLP reduces

  12. Three Sisters Dam modifications and performance

    Energy Technology Data Exchange (ETDEWEB)

    Courage, L.J.R. [Monenco AGRA Inc., Calgary, AB (Canada)

    1995-12-31

    Recent modifications and maintenance carried out at the Three Sisters Dam, in the Alberta Rockies south of the town of Canmore, were described. A detailed account was given of the dam`s geological setting, its abnormally high leakage through the foundation and its sinkhole activity. Results of studies aimed at finding the cause of leakage and sinkhole occurrences were reviewed. Modifications made to the dam since 1951 were detailed, as were modifications to handle probable maximum flood levels. Three approaches for estimating failure probabilities after identification of failure modes were described. The overall conclusion was that based on constant leakage, no settlement in the dam, penstocks, or the powerhouse since construction, the Three Sisters Dam was stable. 1 ref.

  13. The changing hydrology of a dammed Amazon

    Science.gov (United States)

    Timpe, Kelsie; Kaplan, David

    2017-01-01

    Developing countries around the world are expanding hydropower to meet growing energy demand. In the Brazilian Amazon, >200 dams are planned over the next 30 years, and questions about the impacts of current and future hydropower in this globally important watershed remain unanswered. In this context, we applied a hydrologic indicator method to quantify how existing Amazon dams have altered the natural flow regime and to identify predictors of alteration. The type and magnitude of hydrologic alteration varied widely by dam, but the largest changes were to critical characteristics of the flood pulse. Impacts were largest for low-elevation, large-reservoir dams; however, small dams had enormous impacts relative to electricity production. Finally, the “cumulative” effect of multiple dams was significant but only for some aspects of the flow regime. This analysis is a first step toward the development of environmental flows plans and policies relevant to the Amazon and other megadiverse river basins. PMID:29109972

  14. Exporting dams: China's hydropower industry goes global.

    Science.gov (United States)

    McDonald, Kristen; Bosshard, Peter; Brewer, Nicole

    2009-07-01

    In line with China's "going out" strategy, China's dam industry has in recent years significantly expanded its involvement in overseas markets. The Chinese Export-Import Bank and other Chinese financial institutions, state-owned enterprises, and private firms are now involved in at least 93 major dam projects overseas. The Chinese government sees the new global role played by China's dam industry as a "win-win" situation for China and host countries involved. But evidence from project sites such as the Merowe Dam in Sudan demonstrates that these dams have unrecognized social and environmental costs for host communities. Chinese dam builders have yet to adopt internationally accepted social and environmental standards for large infrastructure development that can assure these costs are adequately taken into account. But the Chinese government is becoming increasingly aware of the challenge and the necessity of promoting environmentally and socially sound investments overseas.

  15. Measurement of Dam Deformations: Case Study of Obruk Dam (Turkey)

    Science.gov (United States)

    Gulal, V. Engin; Alkan, R. Metin; Alkan, M. Nurullah; İlci, Veli; Ozulu, I. Murat; Tombus, F. Engin; Kose, Zafer; Aladogan, Kayhan; Sahin, Murat; Yavasoglu, Hakan; Oku, Guldane

    2016-04-01

    In the literature, there is information regarding the first deformation and displacement measurements in dams that were conducted in 1920s Switzerland. Todays, deformation measurements in the dams have gained very different functions with improvements in both measurement equipment and evaluation of measurements. Deformation measurements and analysis are among the main topics studied by scientists who take interest in the engineering measurement sciences. The Working group of Deformation Measurements and Analysis, which was established under the International Federation of Surveyors (FIG), carries out its studies and activities with regard to this subject. At the end of the 1970s, the subject of the determination of fixed points in the deformation monitoring network was one of the main subjects extensively studied. Many theories arose from this inquiry, as different institutes came to differing conclusions. In 1978, a special commission with representatives of universities has been established within the FIG 6.1 working group; this commission worked on the issue of determining a general approach to geometric deformation analysis. The results gleaned from the commission were discussed at symposiums organized by the FIG. In accordance with these studies, scientists interested in the subject have begun to work on models that investigate cause and effect relations between the effects that cause deformation and deformation. As of the scientist who interest with the issue focused on different deformation methods, another special commission was established within the FIG engineering measurements commission in order to classify deformation models and study terminology. After studying this material for a long time, the official commission report was published in 2001. In this prepared report, studies have been carried out by considering the FIG Engineering Surveying Commission's report entitled, 'MODELS AND TERMINOLOGY FOR THE ANALYSIS OF GEODETIC MONITORING OBSERVATIONS

  16. [Effects of perinatal exposure to bisphenol A inducing dopaminergic neuronal cell to apoptosis happening in midbrain of male rat offspring].

    Science.gov (United States)

    Lin, Yong; Zhang, Hao; Wang, Wen-dong; Wu, De-sheng; Jiang, Song-hui; Qu, Wei-dong

    2006-07-01

    To investigate the mechanism and effect of rat perinatal exposure to bisphenol A (BPA) resulting in midbrain dopaminergic neuronal cell apoptosis and tyrosine hydroxylase expression of male offspring. Rat dams were randomLy divided into 4 groups on gestational day(GD) 10 and given orally the bisphenol A doses as 0, 0.5, 5, 50 mg/kg x d from GD10 to weaning. The brains of male offspring were obtained for detecting, with immunohistochemistry protocol, the Caspase-3, Bcl-2 and tyrosine hydroxylase expression in the midbrain on postnatal day 21 or 30 respectively, and the midbrain apoptotic neuronal cell were detected by TUNEL on PND21. The expression of Caspase-3 in the midbrain of rat male offspring were increased but bcl-2 were decreased on PND21 and 30, respectively. On PND21, apoptotic neuronal cell were found in the midbrain of high and medium doses groups. TH protein expression was decreased. Perinatal exposure to bisphenol A can induce the apoptosis of midbrain dopaminergic neuron in the male rat offspring even after weaning, and concomitantly decrease the midbrain TH immunoreactivity, this may cause the abnormal function of dopaminergic pathway of rat male offspring.

  17. Dam safety management in Victoria (Australia)

    International Nuclear Information System (INIS)

    Adem, J.

    1996-01-01

    The Victoria state government's decision to make dam owners accountable for safety and upkeep of their dams was reported. To give effect to this decision a series of guidelines have been developed which outline the required activities and skills to ensure that dams are properly managed within a framework of 'light-handed' regulation. The guidelines are also intended to ensure that dam management becomes an integral part of the business decision making process, not just a set of prescribed technical procedures. Details of the direction being taken and the proposed controls to ensure compliance with national and international standards were described. 4 refs., 2 figs

  18. Numerical modelling for stability of tailings dams

    OpenAIRE

    Auchar, Muhammad; Mattsson, Hans; Knutsson, Sven

    2013-01-01

    A tailings dam is a large embankment structure that is constructed to store the waste from the mining industry. Stability problems may occur in a tailings dam due to factors such as quick rate of raising, internal erosion and liquefaction. The failure of a tailings dam may cause loss of human life and environmental degradation. Tailings Dams must not only be stable during the time the tailings storage facility is in operation, but also long time after the mine is closed. In Sweden, the licens...

  19. Brazil's Amazonian dams: Ecological and socioeconomic impacts

    Science.gov (United States)

    Fearnside, P. M.

    2016-12-01

    Brazil's 2015-2024 Energy Expansion Plan calls for 11 hydroelectric dams with installed capacity ≥ 30 MW in the country's Amazon region. Dozens of other large dams are planned beyond this time horizon, and dams with environmental and socioeconomic impacts. Loss of forest to flooding is one, the Balbina and Tucuruí Dams being examples (each 3000 km2). If the Babaquara/Altamira Dam is built it will flood as much forest as both of these combined. Some planned dams imply loss of forest in protected areas, for example on the Tapajós River. Aquatic and riparian ecosystems are lost, including unique biodiversity. Endemic fish species in rapids on the Xingu and Tapajós Rivers are examples. Fish migrations are blocked, such as the commercially important "giant catfish" of the Madeira River. Dams emit greenhouse gases, including CO2 from the trees killed and CH4 from decay under anoxic conditions at the bottom of reservoirs. Emissions can exceed those from fossil-fuel generation, particularly over the 20-year period during which global emissions must be greatly reduced to meet 1.5-2°C limit agreed in Paris. Carbon credit for dams under the Climate Convention causes further net emission because the dams are not truly "additional." Anoxic environments in stratified reservoirs cause methylation of mercury present in Amazonian soils, which concentrates in fish, posing a health risk to human consumers. Population displacement is a major impact; for example, the Marabá Dam would displace 40,000 people, mostly traditional riverside dwellers (ribeirinhos). Various dams impact indigenous peoples, such as the Xingu River dams (beginning with Belo Monte) and the São Luiz do Tapajós and Chacorão Dams on the Tapajós River. Brazil has many energy options other than dams. Much energy use has little benefit for the country, such as exporting aluminum. Electric showerheads use 5% of the country's power. Losses in transmission lines (20%) are far above global averages and can be

  20. Japan`s largest composition dam, aiming for harmony with nature. Chubetsu dam; Shizen tono chowa wo mezasu, Nippon ichi no fukugo dam. Chubetsu dam

    Energy Technology Data Exchange (ETDEWEB)

    Mizushima, T. [Hokkaido Development Bureau, Hokkaido Development Agency, Sapporo (Japan)

    1994-08-15

    This paper introduces Chubetsu Dam planned with a large-scale embankment having a river bed width of 600 m. Chubetsu Dam is being constructed with such objectives as flood control of Ishikari River, river flow rate maintenance, drinking water supply, irrigation water supply and power generation. The dam site is a gravel bed having a river bed width of 600 m and a maximum foundation rock thickness of 40 m, requiring evaluations as a dam foundation and discussions of water shielding methods. As a result of discussions at the Chubetsu Dam technical discussion committee, the dam type is decided to be a composition dam consisting of a gravity type concrete dam on the left river side and a central core type fill dam using a part of the gravel bed as the foundation on the right river side. A continuous underground wall system is planned to be used for shielding water in the gravel foundation. In discussing the anti-seismic properties, analyses for bank construction and water filling to derive stress and deformation conditions prior to an earthquake and a time-history response analysis to derive conditional changes during the earthquake are performed. According to the results thereof, evaluations are given on the safety by compounding the stress and the acceleration. In plans to improve the surrounding areas, an area will be provided upstream the reservoir where the water level is kept constant to serve as a bird sanctuary. 7 figs.

  1. Maternal stress induces epigenetic signatures of psychiatric and neurological diseases in the offspring.

    Directory of Open Access Journals (Sweden)

    Fabiola C R Zucchi

    Full Text Available The gestational state is a period of particular vulnerability to diseases that affect maternal and fetal health. Stress during gestation may represent a powerful influence on maternal mental health and offspring brain plasticity and development. Here we show that the fetal transcriptome, through microRNA (miRNA regulation, responds to prenatal stress in association with epigenetic signatures of psychiatric and neurological diseases. Pregnant Long-Evans rats were assigned to stress from gestational days 12 to 18 while others served as handled controls. Gestational stress in the dam disrupted parturient maternal behaviour and was accompanied by characteristic brain miRNA profiles in the mother and her offspring, and altered transcriptomic brain profiles in the offspring. In the offspring brains, prenatal stress upregulated miR-103, which is involved in brain pathologies, and downregulated its potential gene target Ptplb. Prenatal stress downregulated miR-145, a marker of multiple sclerosis in humans. Prenatal stress also upregulated miR-323 and miR-98, which may alter inflammatory responses in the brain. Furthermore, prenatal stress upregulated miR-219, which targets the gene Dazap1. Both miR-219 and Dazap1 are putative markers of schizophrenia and bipolar affective disorder in humans. Offspring transcriptomic changes included genes related to development, axonal guidance and neuropathology. These findings indicate that prenatal stress modifies epigenetic signatures linked to disease during critical periods of fetal brain development. These observations provide a new mechanistic association between environmental and genetic risk factors in psychiatric and neurological disease.

  2. Maternal protein restriction affects gene expression and enzyme activity of intestinal disaccharidases in adult rat offspring

    International Nuclear Information System (INIS)

    Pinheiro, D.F.; Pacheco, P.D.G.; Alvarenga, P.V.; Buratini, J. Jr; Castilho, A.C.S.; Lima, P.F.; Sartori, D.R.S.; Vicentini-Paulino, M.L.M.

    2013-01-01

    This study investigated the consequences of intrauterine protein restriction on the gastrointestinal tract and particularly on the gene expression and activity of intestinal disaccharidases in the adult offspring. Wistar rat dams were fed isocaloric diets containing 6% protein (restricted, n = 8) or 17% protein (control, n = 8) throughout gestation. Male offspring (n = 5-8 in each group) were evaluated at 3 or 16 weeks of age. Maternal protein restriction during pregnancy produced offspring with growth restriction from birth (5.7 ± 0.1 vs 6.3 ± 0.1 g; mean ± SE) to weaning (42.4 ± 1.3 vs 49.1 ± 1.6 g), although at 16 weeks of age their body weight was similar to control (421.7 ± 8.9 and 428.5 ± 8.5 g). Maternal protein restriction also increased lactase activity in the proximal (0.23 ± 0.02 vs 0.15 ± 0.02), medial (0.30 ± 0.06 vs 0.14 ± 0.01) and distal (0.43 ± 0.07 vs 0.07 ± 0.02 U·g -1 ·min -1 ) small intestine, and mRNA lactase abundance in the proximal intestine (7.96 ± 1.11 vs 2.38 ± 0.47 relative units) of 3-week-old offspring rats. In addition, maternal protein restriction increased sucrase activity (1.20 ± 0.02 vs 0.91 ± 0.02 U·g -1 ·min -1 ) and sucrase mRNA abundance (4.48 ± 0.51 vs 1.95 ± 0.17 relative units) in the duodenum of 16-week-old rats. In conclusion, the present study shows for the first time that intrauterine protein restriction affects gene expression of intestinal enzymes in offspring

  3. Prenatal zinc reduces stress response in adult rat offspring exposed to lipopolysaccharide during gestation.

    Science.gov (United States)

    Galvão, Marcella C; Chaves-Kirsten, Gabriela P; Queiroz-Hazarbassanov, Nicolle; Carvalho, Virgínia M; Bernardi, Maria M; Kirsten, Thiago B

    2015-01-01

    Previous investigations by our group have shown that prenatal treatment with lipopolysaccharide (LPS; 100 μg/kg, intraperitoneally) on gestation day (GD) 9.5 in rats, which mimics infections by Gram-negative bacteria, induces short- and long-term behavioral and neuroimmune changes in the offspring. Because LPS induces hypozincemia, dams were treated with zinc after LPS in an attempt to prevent or ameliorate the impairments induced by prenatal LPS exposure. LPS can also interfere with hypothalamic-pituitary-adrenal (HPA) axis development; thus, behavioral and neuroendocrine parameters linked to HPA axis were evaluated in adult offspring after a restraint stress session. We prenatally exposed Wistar rats to LPS (100 μg/kg, intraperitoneally, on GD 9.5). One hour later they received zinc (ZnSO4, 2 mg/kg, subcutaneously). Adult female offspring that were in metestrus/diestrus were submitted to a 2 h restraint stress session. Immediately after the stressor, 22 kHz ultrasonic vocalizations, open field behavior, serum corticosterone and brain-derived neurotrophic factor (BDNF) levels, and striatal and hypothalamic neurotransmitter and metabolite levels were assessed. Offspring that received prenatal zinc after LPS presented longer periods in silence, increased locomotion, and reduced serum corticosterone and striatal norepinephrine turnover compared with rats treated with LPS and saline. Prenatal zinc reduced acute restraint stress response in adult rats prenatally exposed to LPS. Our findings suggest a potential beneficial effect of prenatal zinc, in which the stress response was reduced in offspring that were stricken with infectious/inflammatory processes during gestation. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Maternal high-fat diet induces metabolic stress response disorders in offspring hypothalamus.

    Science.gov (United States)

    Nguyen, Long The; Saad, Sonia; Tan, Yi; Pollock, Carol; Chen, Hui

    2017-07-01

    Maternal obesity has been shown to increase the risk of obesity and related disorders in the offspring, which has been partially attributed to changes of appetite regulators in the offspring hypothalamus. On the other hand, endoplasmic reticulum (ER) stress and autophagy have been implicated in hypothalamic neuropeptide dysregulation, thus may also play important roles in such transgenerational effect. In this study, we show that offspring born to high-fat diet-fed dams showed significantly increased body weight and glucose intolerance, adiposity and plasma triglyceride level at weaning. Hypothalamic mRNA level of the orexigenic neuropeptide Y (NPY) was increased, while the levels of the anorexigenic pro-opiomelanocortin (POMC), NPY1 receptor (NPY1R) and melanocortin-4 receptor (MC4R) were significantly downregulated. In association, the expression of unfolded protein response (UPR) markers including glucose-regulated protein (GRP)94 and endoplasmic reticulum DNA J domain-containing protein (Erdj)4 was reduced. By contrast, protein levels of autophagy-related genes Atg5 and Atg7, as well as mitophagy marker Parkin, were slightly increased. The administration of 4-phenyl butyrate (PBA), a chemical chaperone of protein folding and UPR activator, in the offspring from postnatal day 4 significantly reduced their body weight, fat deposition, which were in association with increased activating transcription factor (ATF)4, immunoglobulin-binding protein (BiP) and Erdj4 mRNA as well as reduced Parkin, PTEN-induced putative kinase (PINK)1 and dynamin-related protein (Drp)1 protein expression levels. These results suggest that hypothalamic ER stress and mitophagy are among the regulatory factors of offspring metabolic changes due to maternal obesity. © 2017 Society for Endocrinology.

  5. Transplacental and early life exposure to inorganic arsenic affected development and behavior in offspring rats

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Shuhua; Jin, Yaping; Sun, Guifan [China Medical University, Department of Environmental and Occupational Health, College of Public Health, Shenyang, Liaoning (China); Sun, Wenjuan; Wang, Fengzhi [Shenyang Medical College, Department of Preventive Medicine, Shenyang, Liaoning (China)

    2009-06-15

    To evaluate the developmental neurotoxicity of arsenic in offspring rats by transplacental and early life exposure to sodium arsenite in drinking water, the pregnant rats or lactating dams, and weaned pups were given free access to drinking water, which contained arsenic at concentrations of 0, 10, 50, 100 mg/L from GD 6 until PND 42. A battery of physical and behavioral tests was applied to evaluate the functional outcome of pups. Pups in arsenic exposed groups weighed less than controls throughout lactation and weaning. Body weight of 10, 50 and 100 mg/L arsenic exposed groups decreased significantly on PND 42, 16 and 12, respectively. Physical development (pinna unfolding, fur appearance, incisor eruption, or eye opening) in pups displayed no significant differences between control and arsenic treated groups. The number of incidences within the 100 mg/L arsenic treated group, in tail hung, auditory startle and visual placing showed significant decrease compared to the control group (p<0.05). In square water maze test, the trained numbers to finish the trials successfully in 50 and 100 mg/L arsenic exposed groups increased remarkably compared to control group, and there was a dose-related increase (p<0.01) observed. Taken together, these data show that exposure of inorganic arsenite to pregnant dams and offspring pups at levels up to 100 mg/L in drinking water may affect their learning and memory functions and neuromotor reflex. (orig.)

  6. Effects of Paternal Predation Risk and Rearing Environment on Maternal Investment and Development of Defensive Responses in the Offspring

    Science.gov (United States)

    Bauer, Jessica

    2016-01-01

    Abstract Detecting past experiences with predators of a potential mate informs a female about prevailing ecological threats, in addition to stress-induced phenotypes that may be disseminated to offspring. We examined whether prior exposure of a male rat to a predator (cat) odor influences the attraction of a female toward a male, subsequent mother–infant interactions and the development of defensive (emotional) responses in the offspring. Females displayed less interest in males that had experienced predator odor. Mothers that reared young in larger, seminaturalistic housing provided more licking and grooming and active arched back-nursing behavior toward their offspring compared with dams housed in standard housing, although some effects interacted with paternal experience. Paternal predation risk and maternal rearing environment revealed sex-dependent differences in offspring wean weight, juvenile social interactions, and anxiety-like behavior in adolescence. Additionally, paternal predator experience and maternal housing independently affected variations in crf gene promoter acetylation and crf gene expression in response to an acute stressor in offspring. Our results show for the first time in mammals that variation among males in their predator encounters may contribute to stable behavioral variation among females in preference for mates and maternal care, even when the females are not directly exposed to predator threat. Furthermore, when offspring were exposed to the same threat experienced by the father, hypothalamic crf gene regulation was influenced by paternal olfactory experience and early housing. These results, together with our previous findings, suggest that paternal stress exposure and maternal rearing conditions can influence maternal behavior and the development of defensive responses in offspring. PMID:27896313

  7. Effects of maternal high-fat diet and sedentary lifestyle on susceptibility of adult offspring to ozone exposure in rats.

    Science.gov (United States)

    Gordon, C J; Phillips, P M; Johnstone, A F M; Schmid, J; Schladweiler, M C; Ledbetter, A; Snow, S J; Kodavanti, U P

    2017-05-01

    Epidemiological and experimental data suggest that obesity exacerbates the health effects of air pollutants such as ozone (O 3 ). Maternal inactivity and calorically rich diets lead to offspring that show signs of obesity. Exacerbated O 3 susceptibility of offspring could thus be manifested by maternal obesity. Thirty-day-old female Long-Evans rats were fed a control (CD) or high-fat (HF) (60% calories) diet for 6 wks and then bred. GD1 rats were then housed with a running wheel (RW) or without a wheel (SED) until parturition, creating four groups of offspring: CD-SED, CD-RW, HF-SED and HF-RW. HF diet was terminated at PND 35 and all offspring were placed on CD. Body weight and %fat of dams were greatest in order; HF-SED > HF-RW > CD-SED > CD-RW. Adult offspring were exposed to O 3 for two consecutive days (0.8 ppm, 4 h/day). Glucose tolerance tests (GTT), ventilatory parameters (plethysmography), and bronchoalveolar fluid (BALF) cell counts and protein biomarkers were performed to assess response to O 3 . Exercise and diet altered body weight and %fat of young offspring. GTT, ventilation and BALF cell counts were exacerbated by O 3 with responses markedly exacerbated in males. HF diet and O 3 led to significant exacerbation of several BALF parameters: total cell count, neutrophils and lymphocytes were increased in male HF-SED versus CD-SED. Males were hyperglycemic after O 3 exposure and exhibited exacerbated GTT responses. Ventilatory dysfunction was also exacerbated in males. Maternal exercise had minimal effects on O 3 response. The results of this exploratory study suggest a link between maternal obesity and susceptibility to O 3 in their adult offspring in a sex-specific manner.

  8. Technical Specifications, Beaver Valley Power Station, Unit No. 2 (Docket No. 50-412): Appendix A to License No. NPF-64

    International Nuclear Information System (INIS)

    1987-05-01

    Information is presented for Beaver Valley-2 Reactor for the areas of safety limits, limiting safety system settings, limiting conditions for operating and surveillance requirements, design features, and administrative control. (FI)

  9. 75 FR 19895 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-04-16

    ... CFR part 10, Environmental Consideration. An environmental impact assessment has not been prepared... Areas Docket No.: FEMA-B-1032 Beaver Dam Lake Entire shoreline +874 City of Beaver Dam, City of Fox Lake, Unincorporated Areas of Dodge County. Beaver Dam River Approximately 377 feet +841 City of Beaver Dam, downstream...

  10. Olympic Dam - the first decade

    International Nuclear Information System (INIS)

    Newton, A.W.; Wilson, M.A.; Harris, J.

    1988-01-01

    Most aspects of the pre-production phase of the Olympic Dam Project, from commencement of exploration in May 1975 through to commitment to development in December 1985 are documented here. The discovery by Western Mining Corporation Ltd of copper mineralisation on Roxby Downs Station in July 1975 has led to one of the more intensive base-metal exploration programmes undertaken in Australia. Comprehensive exploration, evaluation and feasibility studies between 1975 and 1985 have delineated a probable 450 million tonnes of higher grade ore containing 2.5% copper, 0.8 kg/t uranium oxide, 0.6 g/t gold and 6.0 g/t silver. The total resource is estimated at 2 billion tonnes containing 1.6% copper, 0.6 kg/t uranium oxide, 0.6 g/t gold and 3.5 g/t silver. At 31 December 1985, over 540 km of surface and underground drilling had been completed, comprising over 700 surface drillholes totalling 234 km of core and 218 km of open-hole drilling, and about 900 underground diamond-drillholes totalling 90 km. The Whenan Shaft had been sunk to 500 m and driving on three levels totalled almost 10 km. More than one million tonnes of ore and mullock were raised during development. A pilot treatment plant commissioned on site produced concentrates, matte and blister copper, and ammonium diuranate. Following a technical study of the Olympic Dam Project, completed in March 1985, and a subsequent economic feasibility study, it was announced on 11 June 1985 that the initial project was considered to be commercially viable. On 8 December 1985, the joint venturers, Western Mining Corporation Holdings Ltd (51%) and the BP Group (49%), announced their commitment to the Project. An appendix lists the important events that occurred between January 1986 and December 1987 in bringing Olympic Dam to the production state. 26 refs., 17 figs., 5 tabs., ills

  11. MTHFR deficiency or reduced intake of folate or choline in pregnant mice results in impaired short-term memory and increased apoptosis in the hippocampus of wild-type offspring.

    Science.gov (United States)

    Jadavji, N M; Deng, L; Malysheva, O; Caudill, M A; Rozen, R

    2015-08-06

    Genetic or nutritional disturbances in one-carbon metabolism, with associated hyperhomocysteinemia, can result in complex disorders including pregnancy complications and neuropsychiatric diseases. In earlier work, we showed that mice with a complete deficiency of methylenetetrahydrofolate reductase (MTHFR), a critical enzyme in folate and homocysteine metabolism, had cognitive impairment with disturbances in choline metabolism. Maternal demands for folate and choline are increased during pregnancy and deficiencies of these nutrients result in several negative outcomes including increased resorption and delayed development. The goal of this study was to investigate the behavioral and neurobiological impact of a maternal genetic deficiency in MTHFR or maternal nutritional deficiency of folate or choline during pregnancy on 3-week-old Mthfr(+/+) offspring. Mthfr(+/+) and Mthfr(+/-) females were placed on control diets (CD); and Mthfr(+/+) females were placed on folate-deficient diets (FD) or choline-deficient diets (ChDD) throughout pregnancy and lactation until their offspring were 3weeks of age. Short-term memory was assessed in offspring, and hippocampal tissue was evaluated for morphological changes, apoptosis, proliferation and choline metabolism. Maternal MTHFR deficiency resulted in short-term memory impairment in offspring. These dams had elevated levels of plasma homocysteine when compared with wild-type dams. There were no differences in plasma homocysteine in offspring. Increased apoptosis and proliferation was observed in the hippocampus of offspring from Mthfr(+/-) mothers. In the maternal FD and ChDD study, offspring also showed short-term memory impairment with increased apoptosis in the hippocampus; increased neurogenesis was observed in ChDD offspring. Choline acetyltransferase protein was increased in the offspring hippocampus of both dietary groups and betaine was decreased in the hippocampus of FD offspring. Our results reveal short-term memory

  12. Determination of perfluorinated sulfonate and perfluorinated acids in tissues of free-living European beaver (castor fiber L.) by d-SPE/ micro-UHPLC-MS/MS.

    Science.gov (United States)

    Surma, Magdalena; Giżejewski, Zygmunt; Zieliński, Henryk

    2015-10-01

    Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the main representatives of an rising class of persistent organic pollutants (POPs), perfluorochemicals (PFCs). In this study, determination of selected PFCs concentration in liver, brain, tail, adipose and peritoneum tissues of free-living European beaver (Castor fiber L.) was addressed. Tissue samples, collected from beavers living in Masurian Lakeland (NE Poland), were analyzed by dispersive Solid Phase Extraction (d-SPE) with micro-UHPLC-MS/MS system. In a group of ten selected pefrluorinated compounds only two perfluorinated acids (PFOA and PFNA) and one perfluorinated sulfonate (PFOS) were quantified. PFOA was detected in all analysed tissue samples in both female and male beavers in a range from 0.55 to 0.98ngg(-1) ww whereas PFOS was identified in all analyzed female beaver tissues and only in liver, subcutaneous adipose and peritoneum tissues of male beavers at the concentration level from 0.86 to 5.08ngg(-1) ww. PFNA was only identified in female beaver tissues (liver, subcutaneous adipose and peritoneum) in a range from 1.50 to 6.61ngg(-1) ww. This study demonstrated the bioaccumulation of PFCs in tissue samples collected from beavers living in area known as green lungs of Poland. The results provided in this study indicate for the increasing risk of PFCs occurrence in the environment and the level of PFCs in tissue of free-living European beavers may serve as bioindicator of environmental pollution by these compounds. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. National dam inventory provides data for analysis

    International Nuclear Information System (INIS)

    Spragens, L.

    1992-01-01

    The Association of State Dam Safety Officials completed a dam inventory this fall. Information on approximately 90,000 state-regulated dams in the US collected during the four-year inventory is being used to build a database managed by the Federal Emergency Management Agency. In addition to ASDSO's work, the federal government conducted an inventory of federal dams. This data will be added to the state information to form one national database. The database will feature 35 data fields for each entry, including the name of the dam, its size, the name of the nearest downstream community, maximum discharge and storage volume, the date of the last inspection, and details about the emergency action plan. The program is an update of the nation's first dam inventory, required by the Dam Safety Act of 1972. The US Army Corps of Engineers completed the original inventory in 1981. The Water Resources Development Act of 1986 authorized appropriations of $2.5 million for the Corps to update the inventory. FEMA and the Corps entered into an agreement for FEMA to undertake the task for the Corps and to coordinate work on both the federal and state inventories. ASDSO compiles existing information on state-regulated dams into a common format for the database, added missing information, and established a process for continually updating data. ASDSO plans to analyze the information collected for the database. It will look at statistics for the number of dams regulated, communities that could be affected, and the number of high-hazard dams. FEMA is preparing reports for Congress on the project. The reports, which are expected to be ready by May 1993, will include information on the methodology used and facts about regulated dams under state jurisdiction

  14. Fragility Analysis of Concrete Gravity Dams

    Science.gov (United States)

    Tekie, Paulos B.; Ellingwood, Bruce R.

    2002-09-01

    Concrete gravity dams are an important part ofthe nation's infrastructure. Many dams have been in service for over 50 years, during which time important advances in the methodologies for evaluation of natural phenomena hazards have caused the design-basis events to be revised upwards, in some cases significantly. Many existing dams fail to meet these revised safety criteria and structural rehabilitation to meet newly revised criteria may be costly and difficult. A probabilistic safety analysis (PSA) provides a rational safety assessment and decision-making tool managing the various sources of uncertainty that may impact dam performance. Fragility analysis, which depicts fl%e uncertainty in the safety margin above specified hazard levels, is a fundamental tool in a PSA. This study presents a methodology for developing fragilities of concrete gravity dams to assess their performance against hydrologic and seismic hazards. Models of varying degree of complexity and sophistication were considered and compared. The methodology is illustrated using the Bluestone Dam on the New River in West Virginia, which was designed in the late 1930's. The hydrologic fragilities showed that the Eluestone Dam is unlikely to become unstable at the revised probable maximum flood (PMF), but it is likely that there will be significant cracking at the heel ofthe dam. On the other hand, the seismic fragility analysis indicated that sliding is likely, if the dam were to be subjected to a maximum credible earthquake (MCE). Moreover, there will likely be tensile cracking at the neck of the dam at this level of seismic excitation. Probabilities of relatively severe limit states appear to be only marginally affected by extremely rare events (e.g. the PMF and MCE). Moreover, the risks posed by the extreme floods and earthquakes were not balanced for the Bluestone Dam, with seismic hazard posing a relatively higher risk.

  15. Safety Aspects of Sustainable Storage Dams and Earthquake Safety of Existing Dams

    Directory of Open Access Journals (Sweden)

    Martin Wieland

    2016-09-01

    Full Text Available The basic element in any sustainable dam project is safety, which includes the following safety elements: ① structural safety, ② dam safety monitoring, ③ operational safety and maintenance, and ④ emergency planning. Long-term safety primarily includes the analysis of all hazards affecting the project; that is, hazards from the natural environment, hazards from the man-made environment, and project-specific and site-specific hazards. The special features of the seismic safety of dams are discussed. Large dams were the first structures to be systematically designed against earthquakes, starting in the 1930s. However, the seismic safety of older dams is unknown, as most were designed using seismic design criteria and methods of dynamic analysis that are considered obsolete today. Therefore, we need to reevaluate the seismic safety of existing dams based on current state-of-the-art practices and rehabilitate deficient dams. For large dams, a site-specific seismic hazard analysis is usually recommended. Today, large dams and the safety-relevant elements used for controlling the reservoir after a strong earthquake must be able to withstand the ground motions of a safety evaluation earthquake. The ground motion parameters can be determined either by a probabilistic or a deterministic seismic hazard analysis. During strong earthquakes, inelastic deformations may occur in a dam; therefore, the seismic analysis has to be carried out in the time domain. Furthermore, earthquakes create multiple seismic hazards for dams such as ground shaking, fault movements, mass movements, and others. The ground motions needed by the dam engineer are not real earthquake ground motions but models of the ground motion, which allow the safe design of dams. It must also be kept in mind that dam safety evaluations must be carried out several times during the long life of large storage dams. These features are discussed in this paper.

  16. Transmission/disequilibrium tests incorporating unaffected offspring.

    Directory of Open Access Journals (Sweden)

    Qinyu Wei

    Full Text Available We propose a new method for family-based tests of association and linkage called transmission/disequilibrium tests incorporating unaffected offspring (TDTU. This new approach, constructed based on transmission/disequilibrium tests for quantitative traits (QTDT, provides a natural extension of the transmission/disequilibrium test (TDT to utilize transmission information from heterozygous parents to their unaffected offspring as well as the affected offspring from ascertained nuclear families. TDTU can be used in various study designs and can accommodate all types of independent nuclear families with at least one affected offspring. When the study sample contains only case-parent trios, the TDTU is equivalent to TDT. Informative-transmission disequilibrium test (i-TDT and generalized disequilibrium test(GDT are another two methods that can use information of both unaffected offspring and affected offspring. In contract to i-TDT and GDT, the test statistic of TDTU is simpler and more explicit, and can be implemented more easily. Through computer simulations, we demonstrate that power of the TDTU is slightly higher compared to i-TDT and GDT. All the three methods are more powerful than method that uses affected offspring only, suggesting that unaffected siblings also provide information about linkage and association.

  17. Prevalence of agglutinating antibodies to Toxoplasma gondii and Sarcocystis neurona in beavers (Castor canadensis) from Massachusetts

    Science.gov (United States)

    Jordan, C.N.; Kaur, T.; Koenen, K.; DeStefano, S.; Zajac, A.M.; Lindsay, D.S.

    2005-01-01

    The present study examined the seroprevalence of Toxoplasma gondii and Sarcocystls neurona in a population of beavers (Castor canadensis) from Massachusetts. Sixty-two blood samples were collected during the field seasons over 3 consecutive years from different animals. Blood was collected onto filter paper and shipped to the Department of Biomedical Sciences, Virginia Tech, Blacksburg, Virginia, for parasite testing. The samples were tested at dilutions of 1:25, 1:50, and 1:100 against each parasite antigen by modified agglutination tests to determine whether antibodies to either parasite were present in the blood. Six of 62 samples (10%) were positive for T. gondii, with 2 samples having titers of 1:25 and 4 having titers of 1:50. Four of 62 samples (6%) were positive for S. neurona, with 2 samples having titers of 1:25 and 2 having titers of 1:50. ?? American Society of Pathologists 2005.

  18. [Introduction of species and microevolution: the European beaver, raccoon dog, and American mink].

    Science.gov (United States)

    Korablev, N P; Korablev, M P; Korablev, P N

    2011-01-01

    Nine skull samples of the beaver Castor fiber, six samples of the raccoon dog Nyctereutes procyonoides, and six samples of the American mink Neovison vison were studied using phenetic and craniometric methods. Analysis of the phenofund structure suggests that in all of the studied species the emergence of novel character variations does not lead to their fixation with a significant frequency. Considerable morphological variability emerges in the contact zone of different autochtonous populations, of wild and breeding forms, as well as in geographically and reproductively isolated small groups of individuals. Morphological differences of introduced animals fit into the conception of species polymorphism and are smoothed over when separate colonies merge into metapopulations, which does not lead to the emergence of novel stable taxa.

  19. Peripartum Antibiotics Promote Gut Dysbiosis, Loss of Immune Tolerance, and Inflammatory Bowel Disease in Genetically Prone Offspring.

    Science.gov (United States)

    Miyoshi, Jun; Bobe, Alexandria M; Miyoshi, Sawako; Huang, Yong; Hubert, Nathaniel; Delmont, Tom O; Eren, A Murat; Leone, Vanessa; Chang, Eugene B

    2017-07-11

    Factors affecting the developing neonatal gut microbiome and immune networks may increase the risk of developing complex immune disorders such as inflammatory bowel diseases (IBD). In particular, peripartum antibiotics have been suggested as risk factors for human IBD, although direct evidence is lacking. Therefore, we examined the temporal impact of the commonly used antibiotic cefoperazone on both maternal and offspring microbiota when administered to dams during the peripartum period in the IL-10-deficient murine colitis model. By rigorously controlling for cage, gender, generational, and murine pathobiont confounders, we observed that offspring from cefoperazone-exposed dams develop a persistent gut dysbiosis into adulthood associated with skewing of the host immune system and increased susceptibility to spontaneous and chemically dextran sodium sulfate (DSS)-induced colitis. Thus, early life exposure to antibiotic-induced maternal dysbiosis during a critical developmental window for gut microbial assemblage and immune programming elicits a lasting impact of increased IBD risk on genetically susceptible offspring. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  20. Antagonistic parent-offspring co-adaptation.

    Directory of Open Access Journals (Sweden)

    Mathias Kölliker

    2010-01-01

    Full Text Available In species across taxa, offspring have means to influence parental investment (PI. PI thus evolves as an interacting phenotype and indirect genetic effects may strongly affect the co-evolutionary dynamics of offspring and parental behaviors. Evolutionary theory focused on explaining how exaggerated offspring solicitation can be understood as resolution of parent-offspring conflict, but the evolutionary origin and diversification of different forms of family interactions remains unclear.In contrast to previous theory that largely uses a static approach to predict how "offspring individuals" and "parental individuals" should interact given conflict over PI, we present a dynamic theoretical framework of antagonistic selection on the PI individuals obtain/take as offspring and the PI they provide as parents to maximize individual lifetime reproductive success; we analyze a deterministic and a stochastic version of this dynamic framework. We show that a zone for equivalent co-adaptation outcomes exists in which stable levels of PI can evolve and be maintained despite fast strategy transitions and ongoing co-evolutionary dynamics. Under antagonistic co-adaptation, cost-free solicitation can evolve as an adaptation to emerging preferences in parents.We show that antagonistic selection across the offspring and parental life-stage of individuals favors co-adapted offspring and parental behavior within a zone of equivalent outcomes. This antagonistic parent-offspring co-adaptation does not require solicitation to be costly, allows for rapid divergence and evolutionary novelty and potentially explains the origin and diversification of the observed provisioning forms in family life.

  1. Fire effects on the Point Reyes Mountain Beaver (Aplodontia rufa phaea) at Point Reyes National Seashore, 10 years after the Vision Fire

    Science.gov (United States)

    Fellers, Gary M.; Osbourn, Michael

    2009-01-01

    The 1995 Vision Fire burned 5000 ha and destroyed 40% of the habitat of the Point Reyes Mountain Beaver (Aplodontia rufa phaea). Surveys immediately post-fire and in 2000 showed that only 0.4 to 1.7% of Mountain Beavers within the burn area survived. In 2000, dense, ground-hugging Blue-blossom Ceanothus (Ceanothus thrysiflorus) appeared to make coastal scrub thickets much less suitable for Mountain Beavers even though the number of burrows at our 11 study sites had returned to 88% of pre-fire numbers. In 2005 (10 y post-fire), the habitat appeared to be better for Mountain Beavers; Blue-blossom Ceanothus had diminished and vegetation more typical of northern coastal scrub, such as Coyote Brush (Baccharis pilularis) overstory with a lower layer of herbaceous vegetation, had greatly increased; but the number of Mountain Beaver burrows had declined to 52% of pre-fire numbers and there was little change in the number of sites occupied between our 2000 and 2005 surveys. With the expected successional changes in thicket structure, Mountain Beaver populations are likely to recover further, but there will probably be considerable variation in how each population stabilizes.

  2. 226Ra and other radionuclides in water, vegetation, and tissues of beavers (Castor canadensis) from a watershed containing U tailings neat Elliot Lake, Canada

    International Nuclear Information System (INIS)

    Clulow, F.V.; Mirka, M.A.; Dave, N.K.; Lim, T.P.

    1991-01-01

    Radionuclide levels were measured in tissues, gut contents, diet items, and water at site of capture, of adult beavers from the Serpent River drainage basin which contains U tailings at Elliot Lake, Ontario, and from nearby control sites. Levels of 226 Ra in beaver bone, muscle and kidney were highest in animals from locations close to U tailing; liver levels did not vary by site. Environmental 226 Ra levels were within ranges previously reported at these or similar locations elsewhere; levels in beaver gut contents reflected levels in diet items. Concentration ratios exceeded unity only between some vegetation items and beaver bone at the Elliot Lake site and were less than 0.19 between vegetation and other tissues. In two beavers with tissue levels of 226 Ra higher than others sampled, neither 232 Th nor 230 Th were detected in bone, muscle or liver tissues. U-238 was measurable in bone, muscle and liver; 228 Th in bone, 210 Po bone, muscle and liver; and 210 Pb was measurable only in bone. Estimated yearly intakes of radionuclides by people eating beavers were calculated to be below current allowable levels set by the Canadian regulatory authorities. (author)

  3. Decontamination of Beaver Valley steam generators using the CAN-DEREM process

    International Nuclear Information System (INIS)

    Speranzini, R.A.; Helms, M.

    1991-08-01

    Three steam generator channelheads at the Beaver Valley Unit 1 Power Station were decontaminated in September and October of 1989 using the CAN-DEREM process. With system volumes of about 12 000 L for each steam generator, this was the first major application of the CAN-DEREM process, following closely after the successful 1989 April CAN-DEREM decontamination of a 1000 L Indian Point-2 recirculating heat exchanger. The Successful applications were the culmination of several years of laboratory study directed at assessing and subsequently altering the CAN-DECON formulation. The studies were initiated after the CAN-DECON process was implicated in causing intergranular attack in sensitized 304 stainless steel after the Peach Bottom-2 recirculating water cooling unit (RWCU) decontamination in early 1984. The degree of attack was similar to that observed on piping from several early Boiling Water Reactors, and this was the only instance of reactor artifacts revealing intergranular attack after a CAN-DECON decontamination. Nevertheless, utilities were reluctant to use CAN-DECON after the Peach Bottom-2 decontamination. In response the utility concerns, the CAN-DECON formulation was modified to produce the even-less-corrosive CAN-DEREM formulation. In this report, the results of the laboratory corrosion study are briefly summarized along with the results of pre-decontamination assessments using Beaver Valley specimens, and the results of the actual steam generator decontaminations. The results show quite clearly the decontamination effectiveness and the low corrosiveness of the CAN-DEREM process. As a result of the successful laboratory program and demonstrations, the CAN-DEREM process is currently being qualified for use in full heat transport systems of Pressurized Water Reactors in a major program being carried out by Westinghouse in the United States

  4. Maternal postpartum corticosterone and fluoxetine differentially affect adult male and female offspring on anxiety-like behavior, stress reactivity, and hippocampal neurogenesis.

    Science.gov (United States)

    Gobinath, Aarthi R; Workman, Joanna L; Chow, Carmen; Lieblich, Stephanie E; Galea, Liisa A M

    2016-02-01

    Postpartum depression (PPD) affects approximately 15% of mothers, disrupts maternal care, and can represent a form of early life adversity for the developing offspring. Intriguingly, male and female offspring are differentially vulnerable to the effects of PPD. Antidepressants, such as fluoxetine, are commonly prescribed for treating PPD. However, fluoxetine can reach offspring via breast milk, raising serious concerns regarding the long-term consequences of infant exposure to fluoxetine. The goal of this study was to examine the long-term effects of maternal postpartum corticosterone (CORT, a model of postpartum stress/depression) and concurrent maternal postpartum fluoxetine on behavioral, endocrine, and neural measures in adult male and female offspring. Female Sprague-Dawley dams were treated daily with either CORT or oil and fluoxetine or saline from postnatal days 2-23, and offspring were weaned and left undisturbed until adulthood. Here we show that maternal postpartum fluoxetine increased anxiety-like behavior and impaired hypothalamic-pituitary-adrenal (HPA) axis negative feedback in adult male, but not female, offspring. Furthermore, maternal postpartum fluoxetine increased the density of immature neurons (doublecortin-expressing) in the hippocampus of adult male offspring but decreased the density of immature neurons in adult female offspring. Maternal postpartum CORT blunted HPA axis negative feedback in males and tended to increase density of immature neurons in males but decreased it in females. These results indicate that maternal postpartum CORT and fluoxetine can have long-lasting effects on anxiety-like behavior, HPA axis negative feedback, and adult hippocampal neurogenesis and that adult male and female offspring are differentially affected by these maternal manipulations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Ambient conditions and fate and transport simulations of dissolved solids, chloride, and sulfate in Beaver Lake, Arkansas, 2006--10

    Science.gov (United States)

    Green, W. Reed

    2013-01-01

    Beaver Lake is a large, deep-storage reservoir located in the upper White River Basin in northwestern Arkansas, and was completed in 1963 for the purposes of flood control, hydroelectric power, and water supply. Beaver Lake is affected by point and nonpoint sources of minerals, nutrients, and sediments. The City of Fayetteville discharges about half of its sewage effluent into the White River immediately upstream from the backwater of the reservoir. The City of West Fork discharges its sewage effluent into the West Fork of the White River, and the City of Huntsville discharges its sewage effluent into a tributary of War Eagle Creek. A study was conducted to describe the ambient conditions and fate and transport of dissolved solids, chloride, and sulfate concentrations in Beaver Lake. Dissolved solids, chloride, and sulfate are components of wastewater discharged into Beaver Lake and a major concern of the drinking water utilities that use Beaver Lake as their source. A two-dimensional model of hydrodynamics and water quality was calibrated to include simulations of dissolved solids, chloride, and sulfate for the period January 2006 through December 2010. Estimated daily dissolved solids, chloride, and sulfate loads were increased in the White River and War Eagle Creek tributaries, individually and the two tributaries together, by 1.2, 1.5, 2.0, 5.0, and 10.0 times the baseline conditions to examine fate and transport of these constituents through time at seven locations (segments) in the reservoir, from upstream to downstream in Beaver Lake. Fifteen dissolved solids, chloride, and sulfate fate and transport scenarios were compared to the baseline simulation at each of the seven downstream locations in the reservoir, both 2 meters (m) below the surface and 2 m above the bottom. Concentrations were greater in the reservoir at model segments closer to where the tributaries entered the reservoir. Concentrations resulting from the increase in loading became more diluted

  6. Measuring and managing safety at Wahleach Dam

    International Nuclear Information System (INIS)

    Salmon, G. M.; Cattanach, J. D.; Hartford, D. N. D.

    1996-01-01

    Safety improvements recently implemented at the Wahleach Dam were described as one of the first instances in international dam safety practice where risk concepts have been used in conjunction with acceptable risk criteria to evaluate safety of a dam relative to required level of safety. Erosion was identified as the greatest threat to the safety of the dam. In addressing the deficiencies B.C. Hydro formulated a process which advocates a balanced level of safety,i.e. the probability of failure multiplied by the consequences of failure, integrated over a range of initiators. If the risk posed by the dam is lower than a 'tolerable' risk, the dam is considered to be safe enough. In the case of the Wahleach Dam, the inflow design flood (IDF) was selected to be about one half of the probable maximum flow (PMF), hence it was more likely than not that the spillway could pass floods up to and including the PMF. By accepting the determined level of risk, expenditures of several million dollars for design and construction of dam safety improvements were made redundant. Another byproduct of this new concept of risk assessment was the establishment of improved life safety protection by means of an early warning system for severe floods through the downstream community and emergency authorities. 3 refs., 5 tabs

  7. Descriptive characteristics of the large Italian dams

    International Nuclear Information System (INIS)

    Dello Vicario, E.; Petaccia, A.; Savanella, V.

    1999-01-01

    In the present note the characteristics of the Italian dams are examined, underlining, in a statistical view, story, geographical location, types and use of the most important works. Such a review can be useful for a more detailed analysis, both for the dams characterization and for further studies relevant to water resources utilization [it

  8. [Effects of in utero exposure to di(2-ethylhexyl) phthalate on sexual development in female offspring].

    Science.gov (United States)

    Ding, Yu; Gao, Yu; Shi, Rong; Zhou, Yi-Jun; Tian, Ying

    2010-02-01

    To evaluate the ability of di(2-ethylhexyl) phthalate (DEHP) with inducing damage in sexual development of female offspring rats after maternal exposure. On gestational day (GD) 12, pregnant Wistar rats were weighed, encoded and randomly assigned to 5 groups (10 dams per group). From GD 12 through GD 17 each dam was dosed daily by gavage with either corn oil (vehicle control, 1 mgxkg(-1)xd(-1)) or DEHP (1, 250, 750 and 1000 mgxkg(-1)xd(-1)). Then female offspring were monitored for eye opening on postnatal day (PND) 14-17, organ coefficient on PND 22 and the time to vaginal opening on PND 30 - 38 (if vagina did not open during the period, observation time should extent to adult), as well as body weight, time to first estrus. No significant changes were observed on eye opening at any dose, which were (15.8 +/- 0.4) d, (16.3 +/- 0.6) d, (16.0 +/- 0.6) d, (15.9 +/- 0.6) d, (15.8 +/- 0.4) d respectively in control, 1, 250, 750 and 1000 mgxkg(-1)xd(-1) (F = 1.363, P = 0.262). However, 62.50% (15/24), 81.25% (26/32) female offspring were permanently absence of vaginal orifice in 750 and 1000 mgxkg(-1)xd(-1) groups respectively, while control, 1 and 250 mgxkg(-1)xd(-1) groups developed normally with vaginal orifices (chi(2) values were 84.92, 132.79, respectively, P xd(-1). After covariance adjustment for body weight, which can statistically influenced the age of vaginal opening (F = 40.857, P xd(-1) group was advanced than control (t = -2.056, P < 0.05). Exposure to DEHP in utero from GD 12 - 17 can result in abnormalities of sexual development such as the time to vaginal opening and vaginal atresia.

  9. The Impact of Dam-Reservoir-Foundation Interaction on Nonlinear Response of Concrete Gravity Dams

    International Nuclear Information System (INIS)

    Amini, Ali Reza; Motamedi, Mohammad Hossein; Ghaemian, Mohsen

    2008-01-01

    To study the impact of dam-reservoir-foundation interaction on nonlinear response of concrete gravity dams, a two-dimensional finite element model of a concrete gravity dam including the dam body, a part of its foundation and a part of the reservoir was made. In addition, the proper boundary conditions were used in both reservoir and foundation in order to absorb the energy of outgoing waves at the far end boundaries. Using the finite element method and smeared crack approach, some different seismic nonlinear analyses were done and finally, we came to a conclusion that the consideration of dam-reservoir-foundation interaction in nonlinear analysis of concrete dams is of great importance, because from the performance point of view, this interaction significantly improves the nonlinear response of concrete dams

  10. Restoring Environmental Flows by Modifying Dam Operations

    Directory of Open Access Journals (Sweden)

    Brian D. Richter

    2007-06-01

    Full Text Available The construction of new dams has become one of the most controversial issues in global efforts to alleviate poverty, improve human health, and strengthen regional economies. Unfortunately, this controversy has overshadowed the tremendous opportunity that exists for modifying the operations of existing dams to recover many of the environmental and social benefits of healthy ecosystems that have been compromised by present modes of dam operation. The potential benefits of dam "re-operation" include recovery of fish, shellfish, and other wildlife populations valued both commercially and recreationally, including estuarine species; reactivation of the flood storage and water purification benefits that occur when floods are allowed to flow into floodplain forests and wetlands; regaining some semblance of the naturally dynamic balance between river erosion and sedimentation that shapes physical habitat complexity, and arresting problems associated with geomorphic imbalances; cultural and spiritual uses of rivers; and many other socially valued products and services. This paper describes an assessment framework that can be used to evaluate the benefits that might be restored through dam re-operation. Assessing the potential benefits of dam re-operation begins by characterizing the dam's effects on the river flow regime, and formulating hypotheses about the ecological and social benefits that might be restored by releasing water from the dam in a manner that more closely resembles natural flow patterns. These hypotheses can be tested by implementing a re-operation plan, tracking the response of the ecosystem, and continually refining dam operations through adaptive management. The paper highlights a number of land and water management strategies useful in implementing a dam re-operation plan, with reference to a variety of management contexts ranging from individual dams to cascades of dams along a river to regional energy grids. Because many of the

  11. Research progress on dam-break floods

    KAUST Repository

    Wu, Jiansong; Bao, Kai; Zhang, Hui

    2011-01-01

    Because of the catastrophic effects downstream of dam-break failure, more and more researchers around the world have been working on the study of dam-break flows to accurately forecast the downstream inundation mapping. With the rapid development of computer hardware and computing techniques, numerical study on dam-break flows has been a popular research subject. In the paper, the numerical methodologies used to solve the governing partial differential equations of dam-break flows are classified and summarized, and their characteristics and applications are discussed respectively. Furthermore, the fully-developed mathematical models developed in recent decades are reviewed, and also introduced the authors' on-going work. Finally, some possible future developments on modeling the dam-break flows and some solutions are presented and discussed. © 2011 IEEE.

  12. Seismic response of uplifting concrete gravity dams

    International Nuclear Information System (INIS)

    Leger, P.; Sauve, G.; Bhattacharjee, S.

    1992-01-01

    The foundation interaction effects on the seismic response of dam-foundation systems have generally been studied using the linear elastic finite element models. In reality, the foundation can not develop effective tensile stresses to a significant degree along the interface. A two-dimensional finite element model, in which nonlinear gap elements are used at the dam-foundation interface to determine the uplift response of concrete gravity dams subjected to seismic loads, is presented. Time domain analyses were performed for a wide range of modelling assumptions such as dam height, interface uplift pressure, interface mesh density, and earthquake input motions, that were systematically varied to find their influence on the seismic response. The nonlinear interface behavior generally reduces the seismic response of dam-foundation systems acting as a seismic isolation mechanism, and may increase the safety against sliding by reducing the base shear transmitted to the foundation. 4 refs., 5 figs., 6 tabs

  13. Research progress on dam-break floods

    KAUST Repository

    Wu, Jiansong

    2011-08-01

    Because of the catastrophic effects downstream of dam-break failure, more and more researchers around the world have been working on the study of dam-break flows to accurately forecast the downstream inundation mapping. With the rapid development of computer hardware and computing techniques, numerical study on dam-break flows has been a popular research subject. In the paper, the numerical methodologies used to solve the governing partial differential equations of dam-break flows are classified and summarized, and their characteristics and applications are discussed respectively. Furthermore, the fully-developed mathematical models developed in recent decades are reviewed, and also introduced the authors\\' on-going work. Finally, some possible future developments on modeling the dam-break flows and some solutions are presented and discussed. © 2011 IEEE.

  14. Impact of social separation during pregnancy on the manifestation of defensive behaviors related to generalized anxiety and panic throughout offspring development.

    Directory of Open Access Journals (Sweden)

    Flaviane Cristina de Brito Guzzo Soliani

    Full Text Available The multiple insecurities, anatomical, physiological and psychological changes arising from the gestational period can generate an overload of stress in the mother and cause disturbances in the offspring, affecting it throughout its development. The existing analysis linking prenatal stress and offspring's anxiety have divergent results, being limited as to gestational week, type of stressor and age of progeny's assessment. Social separation has been described as a stressor that causes increase in anxiety. Thus, the present study evaluated the effects of social separation applied in one of the three gestational weeks of rat dams on the manifestation of the defensive behaviors related to generalized anxiety disorder and panic in the Elevated T Maze of the male progeny in three stages of development (1, 3 or 6 months of life. It was found, in the offspring of grouped (control dams, increased behaviors associated with generalized anxiety disorder and a reduction of panic-like behaviors throughout development. For animals whose dams were socially separated during pregnancy, the most critical period of exposure was the 2nd gestational week, which affected the acquisition of aversive memory, demonstrated by the impairment on learning of avoidances of the offspring in all ages evaluated. Stressor exposure in this week also increased the avoidances, related to generalized anxiety of progeny in the 1st month and decreased escapes, related to panic in the 3rd month of life and, at the age of 6 months old, an inverse situation, with the reduction of the defensive behaviors associated to generalized anxiety disorder. The results show that, when assessing effects of prenatal stress on the manifestation of anxiety, not only the period of exposure is important, but also the age of offspring assessed.

  15. Heterologous Infection of Pregnant Mice Induces Low Birth Weight and Modifies Offspring Susceptibility to Malaria.

    Directory of Open Access Journals (Sweden)

    Ankur Sharma

    Full Text Available Pregnancy malaria (PM is associated with poor pregnancy outcomes, and can arise due to relapse, recrudescence or a re-infection with heterologous parasites. We have used the Plasmodium chabaudi model of pregnancy malaria in C57BL/6 mice to examine recrudescence and heterologous infection using CB and AS parasite strains. After an initial course of patent parasitemia and first recrudescence, CB but not AS parasites were observed to recrudesce again in most animals that became pregnant. Pregnancy exacerbated heterologous CB infection of AS-experienced mice, leading to mortality and impaired post-natal growth of pups. Parasites were detected in placental blood without evidence of sequestration, unlike P. falciparum but similar to other malaria species that infect pregnant women. Inflammatory cytokine levels were elevated in pregnant females during malaria, and associated with intensity of infection and with poor outcomes. Pups born to dams during heterologous infection were more resistant to malaria infections at 6-7 weeks of age, compared to pups born to malaria-experienced but uninfected dams or to malaria-naïve dams. In summary, our mouse model reproduces several features of human PM, including recrudescences, heterologous infections, poor pregnancy outcomes associated with inflammatory cytokines, and modulation of offspring susceptibility to malaria. This model should be further studied to explore mechanisms underlying PM pathogenesis.

  16. Maternal and post-weaning high-fat, high-sucrose diet modulates glucose homeostasis and hypothalamic POMC promoter methylation in mouse offspring.

    Science.gov (United States)

    Zheng, Jia; Xiao, Xinhua; Zhang, Qian; Yu, Miao; Xu, Jianping; Wang, Zhixin; Qi, Cuijuan; Wang, Tong

    2015-10-01

    Substantial evidence demonstrated that maternal dietary nutrients can significantly determine the susceptibility to developing metabolic disorders in the offspring. Therefore, we aimed to investigate the later-life effects of maternal and postweaning diets interaction on epigenetic modification of the central nervous system in the offspring. We examined the effects of dams fed a high-fat, high-sucrose (FS) diet during pregnancy and lactation and weaned to FS diet continuously until 32 weeks of age. Then, DNA methylation and gene expressions of hypothalamic proopiomelanocortin (POMC) and melanocortin receptor 4 (MC4R) were determined in the offspring. Offspring of FS diet had heavier body weight, impaired glucose tolerance, decreased insulin sensitivity and higher serum leptin level at 32-week age (p diet during gestation, lactation and into 32-week age (p diet offspring (p fat diet predisposes the offspring for obesity, glucose intolerance and insulin resistance in later life. Our findings can advance our thinking around the DNA methylation status of the promoter of the POMC and MC4R genes between long-term high-fat, high-sucrose diet and glucose homeostasis in mouse.

  17. Attenuation by dextromethorphan on the higher liability to morphine-induced reward, caused by prenatal exposure of morphine in rat offspring

    Directory of Open Access Journals (Sweden)

    Tao Pao-Luh

    2009-11-01

    Full Text Available Abstract Co-administration of dextromethorphan (DM with morphine during pregnancy and throughout lactation has been found to reduce morphine physical dependence and tolerance in rat offspring. No evidence was presented, however, for the effect of DM co-administered with morphine during pregnancy on morphine-induced reward and behavioral sensitization (possibly related to the potential to induce morphine addiction in morphine-exposed offspring. Conditioned place preference and locomotor activity tests revealed that the p60 male offspring of chronic morphine-treated female rats were more vulnerable to morphine-induced reward and behavioral sensitization. The administration of a low dose of morphine (1 mg/kg, i.p. in these male offspring also increased the dopamine and serotonin turnover rates in the nucleus accumbens, which implied that they were more sensitive to morphine. Co-administration of DM with morphine in the dams prevented this adverse effect of morphine in the offspring rats. Thus, DM may possibly have a great potential in the prevention of higher vulnerability to psychological dependence of morphine in the offspring of morphine-addicted mothers.

  18. Effects of Offspring and Parental Inbreeding on Parent-Offspring Communication.

    Science.gov (United States)

    Mattey, Sarah N; Richardson, Jon; Ratz, Tom; Smiseth, Per T

    2018-06-01

    There is mounting evidence that inbreeding can have complex effects on social interactions among inbred and outbred individuals. Here, we investigate effects of offspring and maternal inbreeding on parent-offspring communication in the burying beetle Nicrophorus vespilloides. We find effects of the interaction between offspring and maternal inbreeding on maternal behavior. Outbred females provided more direct care toward inbred larvae, while inbred females provided similar levels of direct care toward inbred and outbred larvae. Furthermore, we find direct and indirect effects of offspring inbreeding on offspring begging and maternal behavior, respectively. Inbred larvae spent less time begging than outbred larvae, and (outbred) females provided more direct care and less indirect care toward inbred larvae. Finally, we find effects of the interaction between offspring and maternal inbreeding on larval body mass. Inbred and outbred offspring grew to a similar size when the female was outbred, while inbred offspring were of a smaller size when the female was inbred. Our results suggest that outbred females provided more care toward inbred offspring to compensate for their poor genetic quality. Our study advances our understanding of inbreeding by showing that inbreeding can have direct effects on the behavior of inbred individuals and indirect effects on the behavior of outbred individuals and that indirect effects on outbred individuals may in turn influence the fitness of inbred individuals.

  19. Light and electron microscopy of the European beaver (Castor fiber) stomach reveal unique morphological features with possible general biological significance.

    Science.gov (United States)

    Ziółkowska, Natalia; Lewczuk, Bogdan; Petryński, Wojciech; Palkowska, Katarzyna; Prusik, Magdalena; Targońska, Krystyna; Giżejewski, Zygmunt; Przybylska-Gornowicz, Barbara

    2014-01-01

    Anatomical, histological, and ultrastructural studies of the European beaver stomach revealed several unique morphological features. The prominent attribute of its gross morphology was the cardiogastric gland (CGG), located near the oesophageal entrance. Light microscopy showed that the CGG was formed by invaginations of the mucosa into the submucosa, which contained densely packed proper gastric glands comprised primarily of parietal and chief cells. Mucous neck cells represented beaver stomach was the presence of specific mucus with a thickness up to 950 µm (in frozen, unfixed sections) that coated the mucosa. Our observations suggest that the formation of this mucus is complex and includes the secretory granule accumulation in the cytoplasm of pit cells, the granule aggregation inside cells, and the incorporation of degenerating cells into the mucus.

  20. The role of dams in development

    International Nuclear Information System (INIS)

    Cakmak, C.

    2001-01-01

    Although the amounts of water resources are enough for the entire world, the distribution of them in time and space shows uneven pattern. The water need is increasing with heavy industrial and agricultural requirements, while available water in the world remains as a fixed source. Economic growth, socio-cultural, and environmental developments are being realized following these changes. In order to achieve sustainable management of water resources, these changes have to be taken into consideration in water-related development projects. Demand for water is steadily increasing through out the world, even though the fresh water resources are limited and unevenly distributed, during the past three centuries, the amount of water withdrawn from fresh water resources has increased by a factor of 35, whereas world population by a factor 8. The engineering of dams, which provides regular water from reservoirs of dams to be used in case of demand pattern, is a vital part of the civilization. Dams have played a key rote in the development since the third millennium B C when the first great civilizations evolved on major rivers, such as Tigris-Euphrates, the Nile and the Indus. From these early times dams were built for flood control, water supply, irrigation and navigation. Dams also had been built to produce motive power and electricity since the industrial revolution. Development priorities changed, experience accumulated with the construction and operation of dams. Although the importance of water is well known in the human life and civilization around the world, still various groups argue that expected economic benefits are not being produced and that major environmental, economic and social costs are not being taken into account. By the end of 20th century, there were 45000 large dams in over 150 countries. According to the same classification there are 625 large dams in Turkey. All over the world, 50 % of the large dams were built mainly for irrigation. It is estimated

  1. Teenage parents and their offspring.

    Science.gov (United States)

    Kaufman, J

    1996-06-18

    Teenage parents are cast into adult roles before the role experimentation and identity development tasks of middle adolescence can be completed. Understanding the etiology of this social problem requires an ecological perspective encompassing individual characteristics, person-context variables, and societal factors such as race and social class. Risk factors identified in the literature on adolescent pregnancy in the US include: absence of a future orientation or aspirations, lack of assertiveness and interpersonal skills to control physical intimacy, low socioeconomic status and minority group membership, growing up in a single-parent family, a history of sexual abuse, five or more siblings, a sister or friend who became a teenage mother, lax parental supervision of dating and free time, low self-esteem, and dropping out or failing in school. The limited data on adolescent fathers suggest they have histories of substance use, delinquency, failure to graduate from high school, financial difficulty, and exposure to family violence. The offspring of adolescent parents show a higher incidence of developmental delays and mild mental retardation than children of adults and are at increased risk of child abuse and neglect. Teen parents raised in dysfunctional families tend to perpetuate destructive methods of child rearing and have unrealistic, age-inappropriate expectations for infants and toddlers. Teenage parents' lack of competence can be mitigated, however, by positive living arrangements, a supportive family of origin, peer support groups, quality child care, school-based services, and accurate information about parenting and child development.

  2. Danish holsteins favor bull offspring

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Kirkeby, Carsten; Nielsen, Søren Saxmose

    2015-01-01

    In a previous study from 2014 it was found that US Holstein cows that gave birth to heifer calves produced more milk than cows having bull calves. We wanted to assess whether this is also true for Danish cattle. Data from 578 Danish Holstein herds were analysed with a mixed effect model and contr......In a previous study from 2014 it was found that US Holstein cows that gave birth to heifer calves produced more milk than cows having bull calves. We wanted to assess whether this is also true for Danish cattle. Data from 578 Danish Holstein herds were analysed with a mixed effect model...... and contrary to the findings in the US, we found that cows produced higher volumes of milk if they had a bull calf compared to a heifer calf. We found a significantly higher milk production of 0.28% in the first lactation period for cows giving birth to a bull calf, compared to a heifer calf. This difference...... was even higher when cows gave birth to another bull calf, so having two bull calves resulted in a difference of 0.52% in milk production compared to any other combination of sex of the offspring. Furthermore, we found that farmer assisted calvings were associated with a higher milk yield. Cows...

  3. Parents bereaved by offspring suicide

    DEFF Research Database (Denmark)

    Bolton, James M; Au, Wendy; Leslie, William D

    2013-01-01

    OUTCOME MEASURES Mental and physical disorders, social factors, and treatment use. RESULTS Suicide bereavement was associated with an increased rate of depression (ARR, 2.14; 95% CI, 1.88-2.43), anxiety disorders (ARR, 1.41; 95% CI, 1.24-1.60), and marital breakup (ARR, 1.18; 95% CI, 1.13-1.23) in the 2...... years after the suicide of an offspring, as compared with the 2 years prior to the death. Suicide-bereaved and MVC-bereaved parents had very few differences on predeath to postdeath outcomes. Depression rate increases were greater for MVC-bereaved parents (19.9%) compared with suicide-bereaved parents...... (15.9%; P = .005), whereas suicide-bereaved parents had higher rate increases of hospitalization for mental illness (P = .049). Suicide-bereaved parents were more likely than their MVC-bereaved counterparts to have depression (ARR, 1.30; 95% CI, 1.06-1.61), physical disorders (ARR, 1.32; 95% CI, 1...

  4. Deformation Monitoring and Bathymetry Analyses in Rock-Fill Dams, a Case Study at Ataturk Dam

    Science.gov (United States)

    Kalkan, Y.; Bilgi, S.

    2014-12-01

    Turkey has 595 dams constructed between 1936 and 2013 for the purposes of irrigation, flood control, hydroelectric energy and drinking water. A major portion of the dam basins in Turkey are deprived of vegetation and have slope topography on near surrounding area. However, landscaping covered with forest around the dam basin is desirable for erosion control. In fact; the dams, have basins deprived of vegetation, fill up quickly due to sediment transport. Erosion control and forestation are important factors, reducing the sediment, to protect the water basins of the dams and increase the functioning life of the dams. The functioning life of dams is as important as the investment and construction. Nevertheless, in order to provide safety of human life living around, well planned monitoring is essential for dams. Dams are very large and critical structures and they demand the use or application of precise measuring systems. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. Monitoring is an essential component of the dam after construction and during operation and must en­able the timely detection of any behavior that could deteriorate the dam, potentially result in its shutdown or failure. Considering the time and labor consumed by long-term measurements, processing and analysis of measured data, importance of the small structural motions at regular intervals could be comprehended. This study provides some information, safety and the techniques about the deformation monitoring of the dams, dam safety and related analysis. The case study is the deformation measurements of Atatürk Dam in Turkey which is the 6th largest dam of world considering the filling volume of embankment. Brief information is given about the

  5. Safety evaluation report related to the operation of Beaver Valley Power Station, Unit 2 (Docket No. 50-412)

    International Nuclear Information System (INIS)

    1987-03-01

    This report, Supplement No. 4 to the Safety Evaluation Report for the application filed by the Duquesne Light Company et al. (the applicant) for a license to operate the Beaver Valley Power Station, Unit 2 (Docket No. 50-412), has been prepared by the Office of Nuclear Reactor Regulation of the US Nuclear Regulatory Commission. This supplement reports the status of certain items that had not been resolved when the Safety Evaluation Report and its Supplements 1, 2, and 3 were published

  6. Safety evaluation report related to the operation of Beaver Valley Power Station, Unit 2 (Docket No. 50-412)

    International Nuclear Information System (INIS)

    1986-05-01

    This report, Supplement No. 1 to the Safety Evaluation Report for the application filed by the Duquesne Light Company et al. (the applicant) for a license to operate the Beaver valley Power Station, Unit 2 (Docket No. 50-412), has been prepared by the Office of Nuclear Reactor Regulation of the US Nuclear Regulatory Commission. This supplement reports the status of certain items that had not been resolved at the time the Safety Evaluation Report was published

  7. Reduced levels of NR1 and NR2A with depression-like behavior in different brain regions in prenatally stressed juvenile offspring.

    Directory of Open Access Journals (Sweden)

    Hongli Sun

    Full Text Available Adolescence is a time of continued brain maturation, particularly in limbic and cortical regions, which undoubtedly plays a role in the physiological and emotional changes. Juvenile rats repeatedly exposed to prenatal stress (PS exhibit behavioral features often observed in neuropsychiatric disorders including depression. However, to date the underlying neurological mechanisms are still unclear. In the current study, juvenile offspring rats whose mothers were exposed to PS were evaluated for depression-related behaviors in open field and sucrose preference test. NMDA receptor subunits NR1 and NR2A in the hippocampus, frontal cortex and striatum were assayed by western blotting. The results indicated that PS resulted in several behavioral anomalies in the OFT and sucrose preference test. Moreover, reduced levels of NMDA receptor subunits NR1 and NR2A in the hippocampus, and NR1 in prefrontal cortex and striatum of prenatally stressed juvenile offspring were found. Treatment with MK-801 to pregnant dams could prevent all those changes in the juvenile offspring. Collectivity, these data support the argument that PS to pregnant dams could induce depression-like behavior, which may be involved with abnormal expression of NR1 and NR2A in specific brain regions, and MK-801 may have antidepressant-like effects on the juvenile offspring.

  8. Dam construction in salt rock

    International Nuclear Information System (INIS)

    Stockmann, N.; Beinlich, A.; Flach, D.; Jockwer, N.; Klarr, K.; Krogmann, P.; Miehe, R.; Schmidt, M.W.; Schwaegermann, H.F.; Walter, F.; Yaramanci, U.

    1991-11-01

    Barriers are a major component of the satefy concept for the Gorleben repository. The construction and performance of dams are currently tested within the framework of a project carried out in the Asse salt mine. A measuring programme has been established to give evidence of the sealing capacities of a barrier consisting of an abatement, long-term sealing material, and a hydraulic sealing system. Tests are to be made to verify the barrier's performance for shorter of long time periods (up to about 500 years). The tests are assisted by computed models established for the project. The long-term safety aspects to be studied include such conditions as permeability changes due to mechanical impacts, circulation conditions at the roadside, and the serviceable life and efficiency of the sealing components. (DG) [de

  9. The Manantali dam. Synthesis report

    International Nuclear Information System (INIS)

    Dickmann, M.; Sieburger, Dr; Ficatier, M.; Naudet, M.; Schmidt, M.; Seve, M.

    2009-01-01

    This report proposes an ex-post assessment of the Manantali dam on the Senegal river and of the related investments in Senegal, in Mauritania and in Mali. After a presentation of the methodology adopted for this assessment study performed by several organisms, the report describes the context and the concerned sectors: project costs and funding, framework for irrigated agriculture, and framework for energy. It discusses the relevance of the project with respect to irrigated agriculture and to energy. It assesses the project performance in terms of efficiency and of viability, and with respect to environmental aspects. It presents an overview of the different direct and indirect sector-based partners which are involved in energy or rural development. The next part proposes an assessment of the global impact of the project on development as far as irrigated agriculture, the energy sector, and regional cooperation and integration are concerned. A set of lessons learned and recommendations are then formulated

  10. High rates of energy expenditure and water flux in free-ranging Point Reyes mountain beavers Aplodontia rufa phaea

    Science.gov (United States)

    Crocker, D.E.; Kofahl, N.; Fellers, G.D.; Gates, N.B.; Houser, D.S.

    2007-01-01

    We measured water flux and energy expenditure in free-ranging Point Reyes mountain beavers Aplodontia rufa phaea by using the doubly labeled water method. Previous laboratory investigations have suggested weak urinary concentrating ability, high rates of water flux, and low basal metabolic rates in this species. However, free-ranging measurements from hygric mammals are rare, and it is not known how these features interact in the environment. Rates of water flux (210 ?? 32 mL d-1) and field metabolic rates (1,488 ?? 486 kJ d-1) were 159% and 265%, respectively, of values predicted by allometric equations for similar-sized herbivores. Mountain beavers can likely meet their water needs through metabolic water production and preformed water in food and thus remain in water balance without access to free water. Arginine-vasopressin levels were strongly correlated with rates of water flux and plasma urea : creatinine ratios, suggesting an important role for this hormone in regulating urinary water loss in mountain beavers. High field metabolic rates may result from cool burrow temperatures that are well below lower critical temperatures measured in previous laboratory studies and suggest that thermoregulation costs may strongly influence field energetics and water flux in semifossorial mammals. ?? 2007 by The University of Chicago. All rights reserved.

  11. Hydrologic Change during the Colonial Era of the United States: Beavers and the Energy Cost of Impoundments (Invited)

    Science.gov (United States)

    Green, M. B.; Bain, D. J.; Arrigo, J. S.; Duncan, J. M.; Kumar, S.; Parolari, A.; Salant, N.; Vorosmarty, C. J.; Aloysius, N. R.; Bray, E. N.; Ruffing, C. M.; Witherell, B. B.

    2009-12-01

    Europeans colonized North America in the early 17th century with intentions ranging between long-term inhabitation and quick extraction of resources for economic gain in Europe. Whatever the intentions, the colonists relied on the landscape for resources resulting in dramatic change to the forest and fur-bearing mammal population. We demonstrate that initial exploitation of North American forest and furs caused a substantial decrease in mean water residence time (τ) between 1600 and 1800 A.D. That loss, which regionally changed from 51 to 41 days, contrasts with conventional wisdom that humans tend to diminish variability in water resources by increasing storage capacity and thus increasing τ. The loss of τ resulted from over-hunted beaver for the hat market in Europe. Analysis suggests that colonial era demographics and economics did not allow human resource allocation to impoundment construction on a level matching the historic beaver effort. However, the τ appears to have regionally increased during the 19th century, suggesting that humans eventually began replacing the water storage lost with the beaver. The analysis highlights the energy cost of impounding water, which is likely to continue to be an important factor given the increasing need for stable water resources and finite energy resources.

  12. Revision of Hemiquedius Casey (Staphylinidae, Staphylininae and a review of beetles dependent on beavers and muskrats in North America

    Directory of Open Access Journals (Sweden)

    Adam Brunke

    2017-09-01

    Full Text Available Based on newly discovered characters on the male genitalia, external morphology and an accumulation of ecological data, we revise the single member of the genus Hemiquedius. Two new species, H. infinitus Brunke & Smetana, sp. n. and H. castoris Brunke & Smetana, sp. n., from eastern North America are described, and H. ferox (LeConte, restricted to peninsular Florida, is re-described. Hemiquedius castoris is strongly associated with the microhabitats provided by nest materials of the North American beaver and muskrat. A key to the three species of Hemiquedius is provided and diagnostic characters are illustrated. We also review the beetles known to be obligate associates of beavers and muskrats, and discuss the potential role of these keystone vertebrates in beetle evolution and distribution. Based on nest-associated beetles and their closest living relatives, beaver and muskrat lodges may extend distributions northward by moderating winters, promote sympatric speciation and act as refugia against extinction of lineages on a broader timescale. Further research into these potential impacts by ecologists and evolutionary biologists is encouraged.

  13. Identifying source populations for the reintroduction of the Eurasian beaver, Castor fiber L. 1758, into Britain: evidence from ancient DNA.

    Science.gov (United States)

    Marr, Melissa M; Brace, Selina; Schreve, Danielle C; Barnes, Ian

    2018-02-09

    Establishing true phylogenetic relationships between populations is a critical consideration when sourcing individuals for translocation. This presents huge difficulties with threatened and endangered species that have become extirpated from large areas of their former range. We utilise ancient DNA (aDNA) to reconstruct the phylogenetic relationships of a keystone species which has become extinct in Britain, the Eurasian beaver Castor fiber. We sequenced seventeen 492 bp partial tRNAPro and control region sequences from Late Pleistocene and Holocene age beavers and included these in network, demographic and genealogy analyses. The mode of postglacial population expansion from refugia was investigated by employing tests of neutrality and a pairwise mismatch distribution analysis. We found evidence of a pre-Late Glacial Maximum ancestor for the Western C. fiber clade which experienced a rapid demographic expansion during the terminal Pleistocene to early Holocene period. Ancient British beavers were found to originate from the Western phylogroup but showed no phylogenetic affinity to any one modern relict population over another. Instead, we find that they formed part of a large, continuous, pan-Western European clade that harbored little internal substructure. Our study highlights the utility of aDNA in reconstructing population histories of extirpated species which has real-world implications for conservation planning.

  14. Reference-free SNP discovery for the Eurasian beaver from restriction site-associated DNA paired-end data.

    Science.gov (United States)

    Senn, Helen; Ogden, Rob; Cezard, Timothee; Gharbi, Karim; Iqbal, Zamin; Johnson, Eric; Kamps-Hughes, Nick; Rosell, Frank; McEwing, Ross

    2013-06-01

    In this study, we used restriction site-associated DNA (RAD) sequencing to discover SNP markers suitable for population genetic and parentage analysis with the aim of using them for monitoring the reintroduction of the Eurasian beaver (Castor fibre) to Scotland. In the absence of a reference genome for beaver, we built contigs and discovered SNPs within them using paired-end RAD data, so as to have sufficient flanking region around the SNPs to conduct marker design. To do this, we used a simple pipeline which catalogued the Read 1 data in stacks and then used the assembler cortex_var to conduct de novo assembly and genotyping of multiple samples using the Read 2 data. The analysis of around 1.1 billion short reads of sequence data was reduced to a set of 2579 high-quality candidate SNP markers that were polymorphic in Norwegian and Bavarian beaver. Both laboratory validation of a subset of eight of the SNPs (1.3% error) and internal validation by confirming patterns of Mendelian inheritance in a family group (0.9% error) confirmed the success of this approach. © 2013 John Wiley & Sons Ltd.

  15. TYPOLOGY OF LARGE DAMS. A REVIEW

    Directory of Open Access Journals (Sweden)

    Gheorghe ROMANESCU

    2015-06-01

    Full Text Available The dams represent hydrotechnical constructions meant to ensure a judicious use of water resources. The international literature is extremely rich in data regarding the large dams on Earth. In this context, a hierarchy of the main dams is attempted and the role they play in the economic development of the regions they were built in is underlined. The largest dams are built on the big rivers in Asia, North America, South America and Africa. The reservoirs have multiple roles: electricity production, drinking or industrial water supply, irrigations, recreation, etc. High costs and land fragility do not allow the construction of dams in the places most affected by drought or flood. This is why they are usually built in mountainous areas, at great distance from the populated centres. On the Romanian territory, there are 246 large dams, built in the hydrographical basins of Siret, Olt, Arges, Somes, etc. The largest rivers on Earth, by discharge, (Amazon and Zair do not also include the largest dams because the landform and the type of flow have not allowed such constructions.

  16. Sinkhole remediation at Swinging Bridge Dam

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A. [Devine Tarbell and Associates, Portland, ME (United States)

    2009-07-01

    This case history summary described a piping-related sinkhole that occurred after a flood at the Swinging Bridge Dam. The earth-filled embankment dam was constructed using a hydraulic fill technique. A foundation drilling and grouting program was constructed in areas of the dam founded on jointed sandstone and shale. The storage volumes of the reservoir is 32,000 acre-feet. A sinkhole 25 to 300 feet in diameter was observed on May 5, 2005 along the edge of the dam crest. The sinkhole extended to within 10 feet of the reservoir and was separated by a shallow berm of soil and driftwood. Cracking of the crest extended across an area of 180 feet. Operations staff notified the appropriate agencies, implemented a monitoring program, and mobilized construction equipment and sands for use as emergency sinkhole filler. An increase in tailrace turbidity was observed. Historical records for the dam showed significant cracking during the initial filling of the reservoir. Failure modes included increased pore pressures and seepages resulting in the piping of soil along the outside of the dam conduit. Emergency repairs included chemical grouting and weld repairs in the penstocks. A Federal Emergency Management Agency (FEMA) is currently addressing safety issues associated with conduits through dams. 4 refs., 11 figs.

  17. Taurine and β-alanine intraperitoneal injection in lactating mice modifies the growth and behavior of offspring.

    Science.gov (United States)

    Nishigawa, Takuma; Nagamachi, Satsuki; Chowdhury, Vishwajit S; Yasuo, Shinobu; Furuse, Mitsuhiro

    2018-01-08

    Taurine, one of the sulfur-containing amino acids, has several functions in vivo. It has been reported that taurine acts on γ-aminobutyric acid receptors as an agonist and to promote inhibitory neurotransmission. Milk, especially colostrum, contains taurine and it is known that milk taurine is essential for the normal development of offspring. β-Alanine is transported via a taurine transporter and a protein-assisted amino acid transporter, the same ones that transport taurine. The present study aimed to investigate whether the growth and behavior of offspring could be altered by modification of the taurine concentration in milk. Pregnant ICR mice were separated into 3 groups: 1) a control group, 2) a taurine group, and 3) a β-alanine group. During the lactation periods, dams were administered, respectively, with 0.9% saline (10 ml/kg, i.p.), taurine dissolved in 0.9% saline (43 mg/10 ml/kg, i.p.), or β-alanine dissolved in 0.9% saline (31 mg/10 ml/kg, i.p.). Interestingly, the taurine concentration in milk was significantly decreased by the administration of β-alanine, but not altered by the taurine treatment. The body weight of offspring was significantly lower in the β-alanine group. β-Alanine treatment caused a significant decline in taurine concentration in the brains of offspring, and it was negatively correlated with total distance traveled in the open field test at postnatal day 15. Thus, decreased taurine concentration in the brain induced hyperactivity in offspring. These results suggested that milk taurine may have important role of regulating the growth and behavior of offspring. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. The Dams and Monitoring Systems and Case Study: Ataturk and Karakaya Dams

    Science.gov (United States)

    Kalkan, Y.; Bilgi, S.; Gülnerman, A. G.

    2017-12-01

    Dams are among the most important engineering structures used for flood controls, agricultural purposes as well as drinking and hydroelectric power. Especially after the Second World War, developments on the construction technology, increase the construction of larger capacity dams. There are more than 150.000 dams in the world and almost 1000 dams in Turkey, according to international criteria. Although dams provide benefits to humans, they possess structural risks too. To determine the performance of dams on structural safety, assessing the spatial data is very important. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. These physical data are measured and monitored by the instruments and equipment. Dams and their surroundings have to be monitored by using essential methods at periodic time intervals in order to determine the possible changes that may occur over the time. Monitoring programs typically consist of; surveillance or visual observation. These programs on dams provide information for evaluating the dam's performance related to the design intent and expected changes that could affect the safety performance of the dam. Additionally, these programs are used for investigating and evaluating the abnormal or degrading performance where any remedial action is necessary. Geodetic and non-geodetic methods are used for monitoring. Monitoring the performance of the dams is critical for producing and maintaining the safe dams. This study provides some general information on dams and their different monitoring systems by taking into account two different dams and their structural specifications with the required information. The case study in this paper depends on a comparison of the monitoring surveys on Atatürk Dam and Karakaya Dam, which are constructed on Firat River with two different structural

  19. Sustainability of dams-an evaluation approach

    Science.gov (United States)

    Petersson, E.

    2003-04-01

    Situated in the stream bed of a river, dams and reservoirs interrupt the natural hydrological cycle. They are very sensitive to all kinds of changes in the catchment, among others global impacts on land use, climate, settlement structures or living standards. Vice versa dams strongly affect the spatially distributed, complex system of ecology, economy and society in the catchment both up- and downstream of the reservoir. The occurrence of negative impacts due to large dams led to serious conflicts about future dams. Nevertheless, water shortages due to climatic conditions and their changes, that are faced by enormous water and energy demands due to rising living standards of a growing world population, seem to require further dam construction, even if both supply and demand management are optimised. Although environmental impact assessments are compulsory for dams financed by any of the international funding agencies, it has to be assumed that the projects lack sustainability. Starting from an inventory of today's environmental impact assessments as an integral part of a feasibility study the presentation will identify their inadequacies with regard to the sustainability of dams. To improve the sustainability of future dams and avoid the mistakes of the past, the planning procedures for dams have to be adapted. The highly complex and dynamical system of interrelated physical and non-physical processes, that involves many different groups of stakeholders, constitutes the need for a model-oriented decision support system. In line with the report of the World Commission of Dams an integrated analysis and structure of the complex interrelations between dams, ecology, economy and society will be presented. Thus the system, that a respective tool will be based on, is analysed. Furthermore an outlook will be given on the needs of the potential users of a DSS and how it has to be embedded in the overall planning process. The limits of computer-based decision-support in the

  20. Investigating leaks in dams and reservoirs

    International Nuclear Information System (INIS)

    2003-01-01

    Millions of people throughout the world depend on dams and reservoirs for electricity, water and flood protection. Dams require significant investment to build and maintain, and yet their usefulness and integrity are constantly threatened by leakage and sedimentation. Isotope hydrology techniques, combined with conventional analytical methods, are a cost-effective tool to reduce such threats. The International Atomic Energy Agency is promoting their use to protect these investments and improve management, particularly by supporting specialized teams of scientists and engineers to investigate dam leakage in African countries on request. (IAEA)

  1. Developing an integrated dam safety program

    International Nuclear Information System (INIS)

    Nielsen, N. M.; Lampa, J.

    1996-01-01

    An effort has been made to demonstrate that dam safety is an integral part of asset management which, when properly done, ensures that all objectives relating to safety and compliance, profitability, stakeholders' expectations and customer satisfaction, are achieved. The means to achieving this integration of the dam safety program and the level of effort required for each core function have been identified using the risk management approach to pinpoint vulnerabilities, and subsequently to focus priorities. The process is considered appropriate for any combination of numbers, sizes and uses of dams, and is designed to prevent exposure to unacceptable risks. 5 refs., 1 tab

  2. Geophysics Methods in Electrometric Assessment of Dams

    Energy Technology Data Exchange (ETDEWEB)

    Davydov, V. A., E-mail: davydov-va@yandex.ru; Baidikov, S. V., E-mail: badikek@mail.ru; Gorshkov, V. Yu., E-mail: vitalaa@yandex.ru; Malikov, A. V., E-mail: alex.mal.1986@mail.ru [Russian Academy of Sciences, Geophysical Institute, Ural Branch (Russian Federation)

    2016-07-15

    The safety assessment of hydraulic structures is proposed to be conducted via geoelectric measurements, which are capable of assessing the health of earth dams in their natural bedding without intervention in their structure. Geoelectric measurements are shown as being capable of pinpointing hazardous parts of a dam, including areas of elevated seepage. Applications of such methods are shown for a number of mini-dams in the Sverdlovsk region. Aparameter (effective longitudinal conductivity) that may be used to monitor the safety of hydraulic structures is proposed. Quantitative estimates of this parameter are given in terms of the degree of safely.

  3. Effect of maternal diet on offspring coping styles in rodents: a systematic review and meta-analysis.

    Science.gov (United States)

    Besson, Anne A; Lagisz, Malgorzata; Senior, Alistair M; Hector, Katie L; Nakagawa, Shinichi

    2016-11-01

    Maternal nutrition can have long-term effects on offspring morphology, physiology and behaviours. However, it is unclear whether mothers 'program' offspring behavioural coping strategy (proactive/reactive) according to the predicted nutritional quality of their future environment. We conducted a systematic review on this topic and meta-analytically synthesized relevant experimental data on mice and rats (46 studies). We included data from experiments where dams were subjected to caloric restriction, protein restriction or overfeeding around gestation and subsequently measured offspring activity, exploration, or anxiety. Overall, little evidence existed for effects of maternal nutrition on the three investigated behavioural traits. The high heterogeneity observed in the data set suggests that maternal programming may sometimes occur. However, because offspring had access to a balanced diet before testing, behaviours may have been reprogrammed. Our results may indicate that reprogrammed behaviours could ameliorate negative effects associated with sub-optimal nutrition in early life. Further, our systematic review revealed clear knowledge gaps and fruitful future research avenues. © 2015 Cambridge Philosophical Society.

  4. Predictions of total deformations in Jebba main dam by finite ...

    African Journals Online (AJOL)

    This paper examined the deformations of the Jebba Main Dam, Jebba Nigeria using the finite element method. The study also evaluated the predicted deformations and compared them with the actual deformations in the dam to identify possible causes of the observed longitudinal crack at the dam crest. The Jebba dam is a ...

  5. The geomorphic legacy of small dams — An Austrian study

    NARCIS (Netherlands)

    Poeppl, R.E.; Keesstra, S.D.; Hein, T.

    2015-01-01

    Dams represent one of the most dominant forms of human impact upon fluvial systems during the Anthropocene, as they disrupt the downstream transfer of water and sediments. Removing dams restores river continuity and channel morphology. Both dam construction and dam removal induce geomorphic channel

  6. Breeder nutrition and offspring performance

    Directory of Open Access Journals (Sweden)

    F Calini

    2007-06-01

    Full Text Available Vertical integration in poultry industry strongly emphasizes the importance of cost control at all levels. In the usual broiler production operations, the costs involved with the production of the hatching egg or the day old chick are negligible if seen in the perspective of the cost per kg of live bird. From a research point of view, anyway, the greatest attention is usually given to the performance of broiler breeders, and most of the research in the field is focused on the improvement of their relative performance, mainly in terms of saleable chicks produced per hen, while less attention has been given to the quality of the chick and to the improvement of its growth performances, even if these last parameters have an effective impact on the overall economics of the poultry growing business. Most of the data available is quite dated, as can be seen from some recent reviews, and in general little attention is given to the impact of parental nutrition on the subsequent broiler performance. It is in fact more usual to find data about dam nutrition influence on egg fertility and hatchability than on subsequent progeny performance. The objectives of this review were to assess, on the basis of published reports, the effects of selected nutrients and anti-nutrients normally prevailing in commercial broiler breeder feeds - vitamins, micro-minerals, mycotoxins, - trying to pinpoint which could be the positive and the negative effects of both on the subsequent broiler performance, with a particular attention to the impact on immune function and carcass yield.

  7. Evaluating safety of concrete gravity dam on weak rock: Scott Dam

    International Nuclear Information System (INIS)

    Goodman, R.E.; Ahlgren, C.S.

    2000-01-01

    Scott Dam is owned and operated by Pacific Gas and Electric Co. (PG and E) as part of the Potter Valley Project. Although it is an unimpressive concrete gravity dam [233 m (765 ft) long with maximum water surface 33.4 m (110 ft) above tail water], the dam has unusually complex and weak foundation rocks; thick condition caused design changes during construction, numerous subsequent special investigations, and several corrections and additions. A main stumbling block to clarification of the dam safety issue for Scott Dam has always been difficulty in characterizing the foundation material. This paper discusses an approach to this problem as well s how the safety of the dam was subsequently confirmed. Following a comprehensive program of research, investigations, and analysis from 1991 to 1997

  8. The influence of parental history of diabetes and offspring birthweight on offspring glucose metabolism in adulthood

    DEFF Research Database (Denmark)

    Lauenborg, Jeannet; Jørgensen, Mie Kw; Damm, Peter

    2011-01-01

    Background. Links are well established between both family history of diabetes and reduced birthweight and increased risk of diabetes in adulthood. Objectives. 1) To investigate the influence of parental history of type 2 diabetes (T2DM) on offspring birthweight and adult offspring glucose tolera...

  9. Developmental Effects of Prenatal Exposure to Bisphenol A on the Uterus of Rat Offspring

    Directory of Open Access Journals (Sweden)

    Gilbert Schönfelder

    2004-09-01

    Full Text Available Exposure to estrogenic compounds during critical periods of fetal development could result in adverse effects on the development of reproductive organs that are not apparent until later in life. Bisphenol A (BPA, which is employed in the manufacture of a wide range of consumer products, is a prime candidate for endocrine disruption. We examined BPA to address the question of whether in utero exposure affects the uterus of the offspring and studied the expression and distribution of the estrogen receptors alpha (ERβ and beta (ERα, because estrogens influence the development, growth, and function of the uterus through both receptors. Gravid Sprague-Dawley dams were administered by gavage either 0.1 or 50 mg/kg per day BPA or 0.2 mg/kg per day 17α-ethinyl estradiol (EE2 as reference dose on gestation days 6 through 21. Female offspring were killed in estrus. Uterine morphologic changes as well as ERα and ERβ distribution and expression were measured by immunohistochemistry and Western blot analysis. Striking morphologic changes were observed in the uterine epithelium of postpubertal offspring during estrus of the in utero BPA-treated animals (the thickness of the total epithelium was significantly reduced. ERβ expression was increased in the 50-mg BPA and EE2-treated group. In contrast, we observed significantly decreased ERβ expression in all BPA- and EE2-treated animals when compared with the control. In summary, these results clearly indicate that in utero exposure of rats to BPA promotes uterine disruption in offspring. We hypothesize that the uterine disruption could possibly be provoked by a dysregulation of ERα and ERβ.

  10. Cues of maternal condition influence offspring selfishness.

    Science.gov (United States)

    Wong, Janine W Y; Lucas, Christophe; Kölliker, Mathias

    2014-01-01

    The evolution of parent-offspring communication was mostly studied from the perspective of parents responding to begging signals conveying information about offspring condition. Parents should respond to begging because of the differential fitness returns obtained from their investment in offspring that differ in condition. For analogous reasons, offspring should adjust their behavior to cues/signals of parental condition: parents that differ in condition pay differential costs of care and, hence, should provide different amounts of food. In this study, we experimentally tested in the European earwig (Forficula auricularia) if cues of maternal condition affect offspring behavior in terms of sibling cannibalism. We experimentally manipulated female condition by providing them with different amounts of food, kept nymph condition constant, allowed for nymph exposure to chemical maternal cues over extended time, quantified nymph survival (deaths being due to cannibalism) and extracted and analyzed the females' cuticular hydrocarbons (CHC). Nymph survival was significantly affected by chemical cues of maternal condition, and this effect depended on the timing of breeding. Cues of poor maternal condition enhanced nymph survival in early broods, but reduced nymph survival in late broods, and vice versa for cues of good condition. Furthermore, female condition affected the quantitative composition of their CHC profile which in turn predicted nymph survival patterns. Thus, earwig offspring are sensitive to chemical cues of maternal condition and nymphs from early and late broods show opposite reactions to the same chemical cues. Together with former evidence on maternal sensitivities to condition-dependent nymph chemical cues, our study shows context-dependent reciprocal information exchange about condition between earwig mothers and their offspring, potentially mediated by cuticular hydrocarbons.

  11. Cues of maternal condition influence offspring selfishness.

    Directory of Open Access Journals (Sweden)

    Janine W Y Wong

    Full Text Available The evolution of parent-offspring communication was mostly studied from the perspective of parents responding to begging signals conveying information about offspring condition. Parents should respond to begging because of the differential fitness returns obtained from their investment in offspring that differ in condition. For analogous reasons, offspring should adjust their behavior to cues/signals of parental condition: parents that differ in condition pay differential costs of care and, hence, should provide different amounts of food. In this study, we experimentally tested in the European earwig (Forficula auricularia if cues of maternal condition affect offspring behavior in terms of sibling cannibalism. We experimentally manipulated female condition by providing them with different amounts of food, kept nymph condition constant, allowed for nymph exposure to chemical maternal cues over extended time, quantified nymph survival (deaths being due to cannibalism and extracted and analyzed the females' cuticular hydrocarbons (CHC. Nymph survival was significantly affected by chemical cues of maternal condition, and this effect depended on the timing of breeding. Cues of poor maternal condition enhanced nymph survival in early broods, but reduced nymph survival in late broods, and vice versa for cues of good condition. Furthermore, female condition affected the quantitative composition of their CHC profile which in turn predicted nymph survival patterns. Thus, earwig offspring are sensitive to chemical cues of maternal condition and nymphs from early and late broods show opposite reactions to the same chemical cues. Together with former evidence on maternal sensitivities to condition-dependent nymph chemical cues, our study shows context-dependent reciprocal information exchange about condition between earwig mothers and their offspring, potentially mediated by cuticular hydrocarbons.

  12. On the response of large dams to incoherent seismic excitation

    International Nuclear Information System (INIS)

    Ramadan, O.; Novak, M.

    1993-01-01

    An intensive parametric study was conducted to investigate the response of concrete gravity dams to horizontal, spatially variable seismic ground motions. Both segmented dams consisting of separate blocks, or monoliths, and continuous monolithic dams are considered. The study includes the effects of various parameters on system natural frequencies, vibration modes, modal displacement ratios, as well as dam displacements and internal stresses due to spatially variable ground motions. The dam analytical model, and dam response to incoherent ground motions are described. The results show that the dam vibrates almost as a rigid body under the fully correlated waves, but bends and twists significantly under the spatially correlated motions. Dam-foundation interaction magnifies the low frequency components of the dam response, more so for a full reservoir, but decreases the high frequency components. For long dams, the effects of spatially incoherent ground motions are qualitatively different and can be much greater than those due to surface travelling waves. 3 refs., 3 figs

  13. [Succession caused by beaver (Castor fiber L.) life activity: II. A refined Markov model].

    Science.gov (United States)

    Logofet; Evstigneev, O I; Aleinikov, A A; Morozova, A O

    2015-01-01

    The refined Markov model of cyclic zoogenic successions caused by beaver (Castor fiber L.) life activity represents a discrete chain of the following six states: flooded forest, swamped forest, pond, grassy swamp, shrubby swamp, and wet forest, which correspond to certain stages of succession. Those stages are defined, and a conceptual scheme of probable transitions between them for one time step is constructed from the knowledge of beaver behaviour in small river floodplains of "Bryanskii Les" Reserve. We calibrated the corresponding matrix of transition probabilities according to the optimization principle: minimizing differences between the model outcome and reality; the model generates a distribution of relative areas corresponding to the stages of succession, that has to be compared to those gained from case studies in the Reserve during 2002-2006. The time step is chosen to equal 2 years, and the first-step data in the sum of differences are given various weights, w (between 0 and 1). The value of w = 0.2 is selected due to its optimality and for some additional reasons. By the formulae of finite homogeneous Markov chain theory, we obtained the main results of the calibrated model, namely, a steady-state distribution of stage areas, indexes of cyclicity, and the mean durations (M(j)) of succession stages. The results of calibration give an objective quantitative nature to the expert knowledge of the course of succession and get a proper interpretation. The 2010 data, which are not involved in the calibration procedure, enabled assessing the quality of prediction by the homogeneous model in short-term (from the 2006 situation): the error of model area distribution relative to the distribution observed in 2010 falls into the range of 9-17%, the best prognosis being given by the least optimal matrices (rejected values of w). This indicates a formally heterogeneous nature of succession processes in time. Thus, the refined version of the homogeneous Markov chain

  14. Dam break analysis and flood inundation map of Krisak dam for emergency action plan

    Science.gov (United States)

    Juliastuti, Setyandito, Oki

    2017-11-01

    The Indonesian Regulation which refers to the ICOLD Regulation (International Committee on Large Dam required have the Emergency Action Plan (EAP) guidelines because of the dams have potential failure. In EAP guidelines there is a management of evacuation where the determination of the inundation map based on flood modeling. The purpose of the EAP is to minimize the risk of loss of life and property in downstream which caused by dam failure. This paper will describe about develop flood modeling and inundation map in Krisak dam using numerical methods through dam break analysis (DBA) using hydraulic model Zhong Xing HY-21. The approaches of dam failure simulation are overtopping and piping. Overtopping simulation based on quadrangular, triangular and trapezium fracture. Piping simulation based on cracks of orifice. Using results of DBA, hazard classification of Krisak dam is very high. The nearest village affected dam failure is Singodutan village (distance is 1.45 kilometer from dam) with inundation depth is 1.85 meter. This result can be used by stakeholders such as emergency responders and the community at risk in formulating evacuation procedure.

  15. 33 CFR 100.1102 - Marine Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam...

    Science.gov (United States)

    2010-07-01

    ... River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona). 100.1102 Section... MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.1102 Marine Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona). (a) General. Sponsors are...

  16. 78 FR 77397 - Flood Control Regulations, Marshall Ford Dam (Mansfield Dam and Lake Travis), Colorado River, Texas

    Science.gov (United States)

    2013-12-23

    ... Regulations, Marshall Ford Dam (Mansfield Dam and Lake Travis), Colorado River, Texas AGENCY: U.S. Army Corps... Marshall Ford Dam (Mansfield Dam and Lake Travis), Colorado River, Texas. In 1997, the Lower Colorado River... regulations to reflect changes in ownership and responsibilities of flood control management of Marshall Ford...

  17. 33 CFR 208.19 - Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Marshall Ford Dam and Reservoir... Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex. The Secretary of the Interior, through his agent, the Lower Colorado River Authority (LCRA) shall operate the Marshall Ford Dam...

  18. The coal deposits of the Alkali Butte, the Big Sand Draw, and the Beaver Creek fields, Fremont County, Wyoming

    Science.gov (United States)

    Thompson, Raymond M.; White, Vincent L.

    1952-01-01

    Large coal reserves are present in three areas located between 12 and 20 miles southeast of Riverton, Fremont County, central Wyoming. Coal in two of these areas, the Alkali Butte coal field and the Big Sand Draw coal field, is exposed on the surface and has been developed to some extent by underground mining. The Beaver Creek coal field is known only from drill cuttings and cores from wells drilled for oil and gas in the Beaver Creek oil and gas field.These three coal areas can be reached most readily from Riverton, Wyo. State Route 320 crosses Wind River about 1 mile south of Riverton. A few hundred yards south of the river a graveled road branches off the highway and extends south across the Popo Agie River toward Sand Draw oil and gas field. About 8 miles south of the highway along the Sand Draw road, a dirt road bears east and along this road it is about 12 miles to the Bell coal mine in the Alkali Butte coal field. Three miles southeast of the Alkali Butte turn-off, 3 miles of oiled road extends southwest into the Beaver Creek oil and gas field. About 6 miles southeast of the Beaver Creek turn-off, in the valley of Little Sand Draw Creek, a dirt road extends east 1. mile and then southeast 1 mile to the Downey mine in the Big Sand Draw coal field. Location of these coal fields is shown on figure 1 with their relationship to the Wind River basin and other coal fields, place localities, and wells mentioned in this report. The coal in the Alkali Butte coal field is exposed partly on the Wind River Indian Reservation in Tps. 1 and 2 S., R. 6 E., and partly on public land. Coal in the Beaver Creek and Big Sand Draw coal fields is mainly on public land. The region has a semiarid climate with rainfall averaging less than 10 in. per year. When rain does fall the sandy-bottomed stream channels fill rapidly and are frequently impassable for a few hours. Beaver Creek, Big Sand Draw, Little Sand Draw, and Kirby Draw and their smaller tributaries drain the area and flow

  19. Dams life; La vie des barrages

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    This paper summarizes the conclusions of the annual inspections of French dams in operation (fissures, water oozing, concrete swelling etc..). Only the observations which require a special attention are reported. (J.S.)

  20. Physical - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  1. Biological - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  2. Seismic risks at Elsie Lake Main Dam

    International Nuclear Information System (INIS)

    McCammon, N.R.; Momenzadeh, M.; Hawson, H.H.; Nielsen, N.M.

    1991-01-01

    The Elsie Lake dams are located on Vancouver Island in an area of high seismic risk. A safety review in 1986 indicated potential deficiencies in the earthfill main dam with respect to modern earthquake design standards. A detailed field investigation program comprising drilling and penetration tests was carried out and the results used in an assessment of seismic stability. A 0.8 m thick less dense layer in the granular shell of the dam, possibly caused by wet construction conditions, would likely liquefy in a major earthquake but sufficient residual strength would likely remain to prevent catastrophic failure. The dam shell might undergo some distortion, and an assessment was initiated to determine the requirements for reservoir drawdown following an extreme earthquake to ensure the timely lowering of the reservoir for inspection and repair. It was suggested that an adequate evacuation capability would be 25% and 50% drawdown in not more than 30 and 50 days, respectively. 9 refs., 11 figs., 1 tab

  3. Can Dams and Reservoirs Cause Earthquakes?

    Indian Academy of Sciences (India)

    induced earthquakes in that region. Figure 1. A cartoon to illus- trate the spatial relation- ships between dam, reser- ... learning experience for us graduate students. Thus, on that ... infallibility and persuasiveness as in Euclidean geometry. The.

  4. Maternal omega-3 supplementation increases fat mass in male and female rat offspring

    Directory of Open Access Journals (Sweden)

    Beverly Sara Muhlhausler

    2011-07-01

    Full Text Available Adipogenesis and lipogenesis are highly sensitive to the nutritional environment in utero and in early postnatal life. Omega-3 long chain polyunsaturated fatty acids (LCPUFA inhibit adipogenesis and lipogenesis in adult rats, however it is not known whether supplementing the maternal diet with omega-3 LCPUFA results in reduced fat deposition in the offspring. Female Albino Wistar rats were fed either a standard chow (Control, n=10 or chow designed to provide ~15mg/kg/day of omega-3 LCPUFA, chiefly as docosahexaenoic acid (DHA, throughout pregnancy and lactation (Omega-3, n=11 and all pups were weaned onto a commercial rat chow. Blood and tissues were collected from pups at 3wks and 6wks of age and weights of visceral and subcutaneous fat depots recorded. The expression of adipogenic and lipogenic genes in the subcutaneous and visceral fat depots were determined using qRT-PCR. Birth weight and postnatal growth were not different between groups. At 6 weeks of age, total percentage body fat was significantly increased in both male (5.09 ± 0.32% vs 4.56 ± 0.2%, P<0.04 and female (5.15 ± 0.37% vs 3.89 ± 0.36%, P<0.04 offspring of omega-3 dams compared to controls. The omega-3 LCPUFA content of erythrocyte phospholipids (as a % of total fatty acids was higher in omega-3 offspring (6.7 ± 0.2 % vs 5.6 ± 0.2%, P<0.001. There was no effect of maternal omega-3 LCPUFA supplementation on the expression of adipogenic or lipogenic genes in the offspring in either the visceral or subcutaneous fat depots. We have therefore established that an omega-3 rich environment during pregnancy and lactation in a rodent model increases fat accumulation in both male and female offspring, particularly in subcutaneous depots, but that this effect is not mediated via upregulation adipogenic/lipogenic gene transcription. These data suggest that maternal n-3 LCPUFA supplementation during pregnancy/lactation may not be an effective strategy for reducing fat deposition in

  5. Centenarian offspring: start healthier and stay healthier.

    Science.gov (United States)

    Adams, Emily R; Nolan, Vikki G; Andersen, Stacy L; Perls, Thomas T; Terry, Dellara F

    2008-11-01

    To assess the relative incidence of age-related diseases in a group of centenarian offspring who have thus far been considered to be predisposed to "healthy" aging. Longitudinal study. Nationwide sample. Four hundred forty centenarian offspring and 192 referent cohort subjects who met inclusion criteria of having initial and follow-up health questionnaire data available. Median age of both cohorts was 72 at the initial health questionnaire. Initial health questionnaires were collected from 1997 to 2006. Follow-up questionnaires were collected from 2004 to 2007. The mean period of follow-up was 3.5+/-1.7 years for the centenarian offspring and 3.9+/-2.2 years for the referent cohort. During the follow-up period, centenarian offspring had a 78% lower risk of myocardial infarction (Padvantages over time over similarly aged referent cohort subjects. These findings reinforce the notion that there may be physiological reasons that longevity runs in families and that centenarian offspring are more likely to age in better cardiovascular health and with a lower mortality than their peers.

  6. Risk assessment of tailings facility dam failure

    OpenAIRE

    Hadzi-Nikolova, Marija; Mirakovski, Dejan; Stefanova, Violeta

    2011-01-01

    This paper presents the consequences of tailings facility dam failure and therefore the needs for its risk assessment. Tailings are fine-grained wastes of the mining industry, output as slurries, due to mixing with water during mineral processing. Tailings dams vary a lot as it is affected by: tailings characteristics and mill output, site characteristics as: topography, hydrology, geology, groundwater, seismicity and available material and disposal methods. The talings which accumulat...

  7. The environmental impact of large dams

    International Nuclear Information System (INIS)

    Razvan, E.

    1992-01-01

    The campaigns of conservationist groups against dams are generally based on rather emotional issues. This paper puts the situation in a more rational perspective, by analysing the various claims which tend to be put forward concerning the impacts of large dams, examining the validity of the arguments, looking at ways in which any adverse effects can be mitigated, and presenting the complexity of the problems. (author)

  8. Estimating flood inundation caused by dam failures

    Energy Technology Data Exchange (ETDEWEB)

    Mocan, N. [Crozier and Associates Inc., Collingwood, ON (Canada); Joy, D.M. [Guelph Univ., ON (Canada). School of Engineering; Rungis, G. [Grand River Conservation Authority, Cambridge, ON (Canada)

    2006-01-15

    Recent advancements in modelling inundation due to dam failures have allowed easier and more illustrative analyses of potential outcomes. This paper described new model and mapping capabilities available using the HEC-RAS hydraulic model in concert with geographic information systems (GIS). The study area was the upper reaches of Canagagigue Creek and the Woolwich Dam near Elmira, Ontario. A hydraulic analysis of a hypothetical dam failure was developed based on the summer probable maximum flood (PMF) event. Limits extended from Woolwich Dam to downstream of the Town of Elmira. An incoming summer PMF hydrograph was set as the upstream boundary condition in the upstream model. Simulation parameters include simulation time-step; implicit weighting factor; water surface calculation tolerance; and output calculation interval. Peak flows were presented, as well as corresponding flood inundation results through the Town of Elmira. The hydraulic model results were exported to a GIS in order to develop inundation maps for emergency management planning. Results from post-processing included inundation maps for each of the simulated time-steps as well as an inundation animation for the duration of the dam breach. It was concluded that the modelling tools presented in the study can be applied to other dam safety assessment projects in order to develop effective and efficient emergency preparedness plans through public consultation and the establishment of impact zones. 1 tab., 2 figs.

  9. Geodetic deformation monitoring at Pendidikan Diponegoro Dam

    Science.gov (United States)

    Yuwono, Bambang Darmo; Awaluddin, Moehammad; Yusuf, M. A.; Fadillah, Rizki

    2017-07-01

    Deformation monitoring is one indicator to assess the feasibility of Dam. In order to get the correct result of the deformation, it is necessary to determine appropriate deformation monitoring network and the observation data should be analyse and evaluated carefully. Measurement and analysis of deformation requires relatively accurate data and the precision is high enough, one of the observation method that used is GPS (Global Positioning System). The research was conducted at Pendidikan Undip Dams is Dam which is located in Tembang. Diponegoro Dam was built in 2013 and a volume of 50.86 m3 of water, inundation normal width of up to 13,500 m2. The main purpose of these building is not only for drainage but also for education and micro hydro power plant etc. The main goal of this reasearch was to monitor and analyze the deformation at Pendidikan Undip Dam and to determaine whether GPS measurement could meet accuracy requirement for dam deformation measurements. Measurements were made 2 times over 2 years, 2015 and 2016 using dual frequency GPS receivers with static methods and processed by Scientific Software GAMIT 10.6

  10. Expectations of immortality: dam safety management into the next millennium

    International Nuclear Information System (INIS)

    Palmer, M.D.

    1999-01-01

    Topics concerning the problems associated with older and aging dams are considered including: what can be done to extent the lifetime of an old dam, the decision to decommission a dam based on a value judgment that the risk of maintaining the dam is too great for society's acceptance, the possibility of change in the level of risk tolerance with time in a technological environment, traditional surveillance methods used by dam owners in the Y2K situation, and the unreality of dam immortality. Trends and means for preserving older dams for their owner's purposes are outlined, as well as their lifetime compared to that of the downstream systems they serve. Despite the fact that we live in a throwaway society, dam owners cannot just leave their dam asset when they are through with using it. Someone has to maintain the dam, or ensure that it is safely decommissioned when the owner is finished with it. On a worldwide scale the available pool of experienced dam engineers is shrinking. This problem needs to be addressed by a shift towards operating and dam safety management skills based on a firm awareness of dam design principles. A shift in society's expectations has occurred such that dam designers and owners must now recognize the impact a dam can have both on its natural and social environments. Because of the increasing emphasis on paying attention to the impacts of people's activities on the planet, engineers more than anyone else must have a significant influence in that direction. 9 refs

  11. Hydraulics of embankment-dam breaching

    Science.gov (United States)

    Walder, J. S.; Iverson, R. M.; Logan, M.; Godt, J. W.; Solovitz, S.

    2012-12-01

    Constructed or natural earthen dams can pose hazards to downstream communities. Experiments to date on earthen-dam breaching have focused on dam geometries relevant to engineering practice. We have begun experiments with dam geometries more like those of natural dams. Water was impounded behind dams constructed at the downstream end of the USGS debris-flow flume. Dams were made of compacted, well-sorted, moist beach sand (D50=0.21 mm), 3.5 m from toe to toe, but varying in height from 0.5 to 1 m; the lower the dam, the smaller the reservoir volume and the broader the initially flat crest. Breaching was started by cutting a slot 30-40 mm wide and deep in the dam crest after filling the reservoir. Water level and pore pressure within the dam were monitored. Experiments were also recorded by an array of still- and video cameras above the flume and a submerged video camera pointed at the upstream dam face. Photogrammetric software was used to create DEMs from stereo pairs, and particle-image velocimetry was used to compute the surface-velocity field from the motion of tracers scattered on the water surface. As noted by others, breaching involves formation and migration of a knickpoint (or several). Once the knickpoint reaches the upstream dam face, it takes on an arcuate form whose continued migration we determined by measuring the onset of motion of colored markers on the dam face. The arcuate feature, which can be considered the head of the "breach channel", is nearly coincident with the transition from subcritical to supercritical flow; that is, it acts as a weir that hydraulically controls reservoir emptying. Photogenic slope failures farther downstream, although the morphologically dominant process at work, play no role at all in hydraulic control aside from rare instances in which they extend upstream so far as to perturb the weir, where the flow cross section is nearly self-similar through time. The domain downstream of the critical-flow section does influence

  12. An Aerial Radiological Survey of the Beaver Valley Power Station and the Surrounding Areas

    International Nuclear Information System (INIS)

    Colton, D.P.

    1999-01-01

    An aerial radiological survey of the Beaver Valley Power Station was conducted during September 18 to 21, 1998, and encompassed a 53.1-square-kilometer area. The survey was conducted by the U. S. Department of Energy's Remote Sensing Laboratory, located in Las Vegas, Nevada, and maintained and operated by Bechtel Nevada. The purpose of the survey was to measure and map the general exposure-rate levels that existed within the survey area and to define the areas of man-made radionuclide activity. The inferred exposure rates were generally uniform and typical of the natural background radiation, which varied from less than 5 to 12 microroentgens per hour. Enhanced exposure rates, not attributable to natural background, and activity from man-made radionuclides were detected over the power station. The detected man-made radionuclide activity was due to the presence of cobalt-60, which is a nuclear activation product, and cesium-137, which is a long-lived fission product. The detected man-made radionuclides were generally consistent with those expected from routine plant operations. Areas outside of the power station boundaries were found to be free of any detectable man-made radionuclides. A series of ground-based, pressurized ionization chamber exposure-rate measurements were acquired at four locations within the survey boundaries. The results of these measurements were compared and found to be within 5 to 30 percent of the corresponding 1998 inferred aerial exposure-rate data

  13. Identification of Placental Aspartic Proteinase in the Eurasian Beaver (Castor fiber L.).

    Science.gov (United States)

    Lipka, Aleksandra; Panasiewicz, Grzegorz; Majewska, Marta; Paukszto, Lukasz; Bieniek-Kobuszewska, Martyna; Szafranska, Bozena

    2018-04-18

    Aspartic proteinases (AP) form a multigenic group widely distributed in various organisms and includes pepsins (pep), cathepsins D and E, pregnancy associated glycoproteins (PAGs) as well as plant, fungal, and retroviral proteinases. This study describes the transcript identification and expression localization of the AP within the discoid placenta of the Castor fiber . We identified 1257 bp of the AP cDNA sequence, encoding 391 amino acids (aa) of the polypeptide precursor composed of 16 aa signal peptide, 46 aa pro-piece, and 329 aa of the mature protein. Within the AP precursor, one site of potential N -glycosylation (NPS 119–121 ) and two Asp residues (D) specific for the catalytic cleft of AP were identified (VLFDTGSSNLWV 91–102 and GIVDTGTSLLTV 277–288 ). The highest homology of the identified placental AP nucleotide and aa sequence was to mouse pepsinogen C (75.8% and 70.1%, respectively). Identified AP also shared high homology with other superfamily members: PAGs, cathepsins, and napsins. The AP identified in this study was named as pepsinogen/PAG-Like (pep/PAG-L). Diversified pep/PAG-L protein profiles with a dominant 58 kDa isoform were identified. Immune reactive signals of the pep/PAG-L were localized within the trophectodermal cells of the beaver placenta. This is the first report describing the placental AP (pep/PAG-L) in the C. fiber .

  14. Parental psychiatric hospitalisation and offspring schizophrenia

    DEFF Research Database (Denmark)

    Sørensen, Holger J; Mortensen, Erik L; Reinisch, June M

    2009-01-01

    The risk of schizophrenia has been linked with a family history of schizophrenia and less strongly with other psychiatric disorders in family members. Using data from the Copenhagen Perinatal Cohort and from the Danish Psychiatric Case Register, we studied the relationship between offspring risk...... of schizophrenia and a range of psychotic and non-psychotic psychiatric diagnoses in parents. Psychiatric admission data after 1969 were available for 7047 cohort members born between 1959 and 1961, and for 7006 mothers and 6993 fathers. Univariate analysis showed that neurosis, alcohol and substance dependence...... in both parents were associated with elevated risk of offspring schizophrenia; in addition, maternal schizophrenia, affective disorder and personality disorder were associated with elevated risk. Controlling for parental age, parental social status, and parental psychiatric co-diagnosis, offspring risk...

  15. The Effects of Dams on Downstream Channel Characteristics in Pennsylvania and Maryland: Assessing the Potential Consequences of Dam Removal

    Science.gov (United States)

    Skalak, K. J.; Pizzuto, J. E.; Jenkins, P.

    2003-12-01

    The potential downstream effects of dam removal were assessed on fifteen sites of varying dam size and characteristics in Pennsylvania and Maryland. The dams ranged in size from a 30 cm high fish weir to a water supply dam 57 m high. Stream order ranged from 1 to 4. The dams are located in watersheds with varying degrees of human disturbance and urbanization. The dams are also operated differently, with significant consequences for hydraulic residence time and downstream flow variability. Most streams were alluvial, but 6 of the reaches were clearly bedrock channels. We hypothesize that the channel upstream, which is unaffected by the dam, will provide an accurate model for the channel downstream of the dam long after dam removal. Therefore, reaches upstream and downstream of the dam were compared to determine the effects of the dam as well as the condition of the stream that will ultimately develop decades after dam removal. Surprisingly, the dams had no consistent influence on channel morphology. However, the percentage of sand is significantly lower downstream than upstream: the mean % sand downstream is 11.47%, while the mean % sand upstream is 21.39%. The coarser fractions of the bed, as represented by the 84th percentile grain diameter, are unaffected by the presence of the dam. These results imply that decades after dam removal, the percentage of sand on the bed will increase, but the coarse fraction of the bed will remain relatively unchanged.

  16. the effect of age of dam on weaning mass for ftve dam breed types

    African Journals Online (AJOL)

    SUMMARY: The effect of age of dam on adjusted 210 day calf weaning mass was estimated by the Least Squares method for 5 dam types on 2 farms. ... the later maturing breeds would have a low level of productivity because these cows would be eliminated in their potentially prime .... time at 28 (2A) or 3l (28) months old.

  17. The interplay of activists and dam developers : the case of Myanmar’s mega-dams

    NARCIS (Netherlands)

    Kirchherr, Julian|info:eu-repo/dai/nl/411261487; J. Charles, Katrina; Walton, Matthew J.

    2017-01-01

    Scholars investigating activism against large dam developments in Asia usually focus on those campaigning, but not on those the campaigns are aimed at–the dam developers. Yet the developers’ perspective is crucial to comprehensively understand the dynamics of social and environmental activism in

  18. Dam that social networking: connecting South Africa's major dams to social media

    CSIR Research Space (South Africa)

    Butgereit, L

    2011-10-01

    Full Text Available where four major South African dams are connected to Twitter and Facebook (and other social media such as MXit and Google Chat) in a mechanism which would be easy to replicate for additional dams or rivers. Data is supplied by the South African...

  19. The Total Risk Analysis of Large Dams under Flood Hazards

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2018-02-01

    Full Text Available Dams and reservoirs are useful systems in water conservancy projects; however, they also pose a high-risk potential for large downstream areas. Flood, as the driving force of dam overtopping, is the main cause of dam failure. Dam floods and their risks are of interest to researchers and managers. In hydraulic engineering, there is a growing tendency to evaluate dam flood risk based on statistical and probabilistic methods that are unsuitable for the situations with rare historical data or low flood probability, so a more reasonable dam flood risk analysis method with fewer application restrictions is needed. Therefore, different from previous studies, this study develops a flood risk analysis method for large dams based on the concept of total risk factor (TRF used initially in dam seismic risk analysis. The proposed method is not affected by the adequacy of historical data or the low probability of flood and is capable of analyzing the dam structure influence, the flood vulnerability of the dam site, and downstream risk as well as estimating the TRF of each dam and assigning corresponding risk classes to each dam. Application to large dams in the Dadu River Basin, Southwestern China, demonstrates that the proposed method provides quick risk estimation and comparison, which can help local management officials perform more detailed dam safety evaluations for useful risk management information.

  20. Hydrogeophysical investigations at Hidden Dam, Raymond, California

    Science.gov (United States)

    Minsley, Burke J.; Burton, Bethany L.; Ikard, Scott; Powers, Michael H.

    2011-01-01

    Self-potential and direct current resistivity surveys are carried out at the Hidden Dam site in Raymond, California to assess present-day seepage patterns and better understand the hydrogeologic mechanisms that likely influence seepage. Numerical modeling is utilized in conjunction with the geophysical measurements to predict variably-saturated flow through typical two-dimensional dam cross-sections as a function of reservoir elevation. Several different flow scenarios are investigated based on the known hydrogeology, as well as information about typical subsurface structures gained from the resistivity survey. The flow models are also used to simulate the bulk electrical resistivity in the subsurface under varying saturation conditions, as well as the self-potential response using petrophysical relationships and electrokinetic coupling equations.The self-potential survey consists of 512 measurements on the downstream area of the dam, and corroborates known seepage areas on the northwest side of the dam. Two direct-current resistivity profiles, each approximately 2,500 ft (762 m) long, indicate a broad sediment channel under the northwest side of the dam, which may be a significant seepage pathway through the foundation. A focusing of seepage in low-topography areas downstream of the dam is confirmed from the numerical flow simulations, which is also consistent with past observations. Little evidence of seepage is identified from the self-potential data on the southeast side of the dam, also consistent with historical records, though one possible area of focused seepage is identified near the outlet works. Integration of the geophysical surveys, numerical modeling, and observation well data provides a framework for better understanding seepage at the site through a combined hydrogeophysical approach.

  1. The Dutch Bipolar Offspring Study: 12-Year Follow-Up

    OpenAIRE

    Mesman, Esther; Nolen, Willem A.; Reichart, Catrien G.; Wals, Marjolein; Hillegers, Manon N. J.

    2013-01-01

    Objective: Offspring of bipolar parents have a genetically increased risk of developing mood disorders. In a longitudinal study, the authors followed a bipolar offspring cohort from adolescence into adulthood to determine the onset, prevalence, and early course of mood disorders and other psychopathology. Method: The Dutch bipolar offspring cohort is a fixed cohort initiated in 1997 (N=140; age range at baseline, 12-21 years). Bipolar offspring were psychiatrically evaluated at baseline and a...

  2. Maternal offspring behaviour in Curraleiro Pé Duro naturalized cattle in Brazil

    Directory of Open Access Journals (Sweden)

    Marlos Castanheira

    2013-08-01

    Full Text Available The objective of the present study consisted of describing dam and calf suckling behaviour of Curraleiro Pé Duro cattle. In this study, 38 mother-offspring pairs and one mother-offspring-orphan trio were observed for 10 hours daily during three consecutive days spaced every four months over a period of one year. After identification, the animals were observed under field conditions where calf posture and the number of suckling episodes (NS, mean suckling duration (MSD, total suckling duration per day (TSD as well as natural weaning of these animals were recorded. The model assessed the effects of calf sex and age as well as feeding time. Suckling episodes (70.6% had a duration of one to five minutes and the calf that suckled in the inverted parallel position had greater chances of success during suckling (99.5%; the younger animals had a shorter mean suckling duration (4.0±0.6 minutes than the older ones (7.5±1.2 minutes but they showed a higher number of suckling episodes (6.29±1.00 vs. 1.33±0.04 feeds in 10 hours for young and older calves. Only the factor age in the first three months was significant for NS, MSD, and TSD; males and females had similar suckling episode length and distribution. While these animals show some traits similar to other cattle breeds such as feeding their calves early in the morning and late in the afternoon, the dams spend large periods of the day away from their calves and suckling is more frequent but for shorter periods of time compared with other breeds. Other unique features such as allo-suckling and formation of day-long crèches are observed in this breed.

  3. Late gestational hypoxia and a postnatal high salt diet programs endothelial dysfunction and arterial stiffness in adult mouse offspring.

    Science.gov (United States)

    Walton, Sarah L; Singh, Reetu R; Tan, Tiffany; Paravicini, Tamara M; Moritz, Karen M

    2016-03-01

    Gestational hypoxia and high dietary salt intake have both been associated with impaired vascular function in adulthood. Using a mouse model of prenatal hypoxia, we examined whether a chronic high salt diet had an additive effect in promoting vascular dysfunction in offspring. Pregnant CD1 dams were placed in a hypoxic chamber (12% O2) or housed under normal conditions (21% O2) from embryonic day 14.5 until birth. Gestational hypoxia resulted in a reduced body weight for both male and female offspring at birth. This restriction in body weight persisted until weaning, after which the animals underwent catch-up growth. At 10 weeks of age, a subset of offspring was placed on a high salt diet (5% NaCl). Pressurized myography of mesenteric resistance arteries at 12 months of age showed that both male and female offspring exposed to maternal hypoxia had significantly impaired endothelial function, as demonstrated by impaired vasodilatation to ACh but not sodium nitroprusside. Endothelial dysfunction caused by prenatal hypoxia was not exacerbated by postnatal consumption of a high salt diet. Prenatal hypoxia increased microvascular stiffness in male offspring. The combination of prenatal hypoxia and a postnatal high salt diet caused a leftward shift in the stress-strain relationship in both sexes. Histopathological analysis of aortic sections revealed a loss of elastin integrity and increased collagen, consistent with increased vascular stiffness. These results demonstrate that prenatal hypoxia programs endothelial dysfunction in both sexes. A chronic high salt diet in postnatal life had an additive deleterious effect on vascular mechanics and structural characteristics in both sexes. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  4. Dextromethorphan attenuated the higher vulnerability to inflammatory thermal hyperalgesia caused by prenatal morphine exposure in rat offspring

    Directory of Open Access Journals (Sweden)

    Chen Chien-Fang

    2011-08-01

    Full Text Available Abstract Background Co-administration of dextromethorphan (DM with morphine during pregnancy and throughout lactation has been found to reduce morphine physical dependence and tolerance in rat offspring. No evidence was presented, however, for the effect of DM co-administered with morphine during pregnancy on inflammatory hyperalgesia in morphine-exposed offspring. Therefore, we attempt to investigate the possible effect of prenatal morphine exposure on the vulnerability to hyperalgesia and the possible therapeutic effect of DM in the present study. Methods Fifty μl of carrageenan (20 mg/ml was injected subcutaneously into the plantar surface of the right hind paw in p18 rats to induce hyperalgesia. Mean paw withdrawal latency was measured in the plantar test to index the severity of hyperalgesia. Using Western blotting and RT-PCR, the quantitative analyses of NMDA receptor NR1 and NR2B subunits were performed in spinal cords from different groups of animals. Results In the carrageenan-induced hyperalgesia model, rat offspring passively exposed to morphine developed a severe hyperalgesia on postnatal day 18 (p18, which also had a more rapid time course than those in the controls. Co-administration of DM with morphine in the dams prevented this adverse effect of morphine in the offspring rats. Western blot and RT-PCR analysis showed that the levels of protein and mRNA of NMDA receptor NR1 and NR2B subunits were significantly higher in the lumbar spinal cords of rats (p14 exposed to prenatal morphine; the co-administration of DM could reverse the effect of morphine on NR1 and attenuate the effect on NR2B. Conclusions Thus, DM may have a great potential in the prevention of higher vulnerability to inflammatory thermal hyperalgesia in the offspring of morphine-addicted mothers.

  5. Prenatal maternal restraint stress exposure alters the reproductive hormone profile and testis development of the rat male offspring.

    Science.gov (United States)

    Pallarés, María Eugenia; Adrover, Ezequiela; Baier, Carlos Javier; Bourguignon, Nadia S; Monteleone, Melisa C; Brocco, Marcela A; González-Calvar, Silvia I; Antonelli, Marta C

    2013-07-01

    Several studies have demonstrated that the presence of stressors during pregnancy induces adverse effects on the neuroendocrine system of the offspring later in life. In the present work, we investigated the effects of early programming on the male reproductive system, employing a prenatal stress (PS) paradigm. This study found that when pregnant dams were placed in a plastic restrainer three times a day during the last week of pregnancy, the offspring showed reduced anogenital distance and delayed testicular descent. Serum luteinising hormone (LH) and follicle-stimulating hormone (FSH) levels were decreased at postnatal day (PND) 28 and testosterone was decreased at PND 75. Increased testosterone plus dihydrotestosterone (T + DHT) concentrations correlated with increased testicular 5α Reductase-1 (5αR-1) mRNA expression at PND 28. Moreover, PS accelerated spermatogenesis at PND 35 and 60, and increased mean seminiferous tubule diameter in pubertal offspring and reduced Leydig cell number was observed at PND 35 and 60. PS offspring had increased androgen receptor (AR) mRNA level at PND 28, and at PND 35 had increased the numbers of Sertoli cells immunopositive for AR. Overall, the results confirm that stress during gestation can induce long-term effects on the male offspring reproductive system. Of particular interest is the pre-pubertal imbalance of circulating hormones that probably trigger accelerated testicular development, followed by an increase in total androgens and a decrease in testosterone concentration during adulthood. Exposure to an unfavourable intrauterine environment might prepare for harsh external conditions by triggering early puberty, increasing reproductive potential.

  6. Hydrogeological framework, numerical simulation of groundwater flow, and effects of projected water use and drought for the Beaver-North Canadian River alluvial aquifer, northwestern Oklahoma

    Science.gov (United States)

    Ryter, Derek W.; Correll, Jessica S.

    2016-01-14

    This report describes a study of the hydrology, hydrogeological framework, numerical groundwater-flow models, and results of simulations of the effects of water use and drought for the Beaver-North Canadian River alluvial aquifer, northwestern Oklahoma. The purpose of the study was to provide analyses, including estimating equal-proportionate-share (EPS) groundwater-pumping rates and the effects of projected water use and droughts, pertinent to water management of the Beaver-North Canadian River alluvial aquifer for the Oklahoma Water Resources Board.

  7. An 11 000-year-long record of fire and vegetation history at Beaver Lake, Oregon, central Willamette Valley

    Science.gov (United States)

    Walsh, Megan K.; Pearl, Christopher A.; Whitlock, Cathy; Bartlein, Patrick J.; Worona, Marc A.

    2010-01-01

    High-resolution macroscopic charcoal and pollen analysis were used to reconstruct an 11??000-year-long record of fire and vegetation history from Beaver Lake, Oregon, the first complete Holocene paleoecological record from the floor of the Willamette Valley. In the early Holocene (ca 11??000-7500 calendar years before present [cal??yr??BP]), warmer, drier summers than at present led to the establishment of xeric woodland of Quercus, Corylus, and Pseudotsuga near the site. Disturbances (i.e., floods, fires) were common at this time and as a result Alnus rubra grew nearby. High fire frequency occurred in the early Holocene from ca 11??200-9300??cal??yr??BP. Riparian forest and wet prairie developed in the middle Holocene (ca 7500??cal??yr??BP), likely the result of a decrease in the frequency of flooding and a shift to effectively cooler, wetter conditions than before. The vegetation at Beaver Lake remained generally unchanged into the late Holocene (from 4000??cal??yr??BP to present), with the exception of land clearance associated with Euro-American settlement of the valley (ca 160??cal??yr BP). Middle-to-late Holocene increases in fire frequency, coupled with abrupt shifts in fire-episode magnitude and charcoal composition, likely indicate the influence anthropogenic burning near the site. The paleoecological record from Beaver Lake, and in particular the general increase in fire frequency over the last 8500??years, differs significantly from other low-elevation sites in the Pacific Northwest, which suggests that local controls (e.g., shifts in vegetation structure, intensification of human land-use), rather than regional climatic controls, more strongly influenced its environmental history. ?? 2010 Elsevier Ltd.

  8. Prenatal Maternal Substance Use and Offspr