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Sample records for wintering sea ducks

  1. Distribution patterns of wintering sea ducks in relation to the North Atlantic Oscillation and local environmental characteristics

    Science.gov (United States)

    Zipkin, Elise F.; Gardner, Beth; Gilbert, Andrew T.; O'Connell, Allan F.; Royle, J. Andrew; Silverman, Emily D.

    2010-01-01

    Twelve species of North American sea ducks (Tribe Mergini) winter off the eastern coast of the United States and Canada. Yet, despite their seasonal proximity to urbanized areas in this region, there is limited information on patterns of wintering sea duck habitat use. It is difficult to gather information on sea ducks because of the relative inaccessibility of their offshore locations, their high degree of mobility, and their aggregated distributions. To characterize environmental conditions that affect wintering distributions, as well as their geographic ranges, we analyzed count data on five species of sea ducks (black scoters Melanitta nigra americana, surf scoters M. perspicillata, white-winged scoters M. fusca, common eiders Somateria mollissima, and long-tailed ducks Clangula hyemalis) that were collected during the Atlantic Flyway Sea Duck Survey for ten years starting in the early 1990s. We modeled count data for each species within ten-nautical-mile linear survey segments using a zero-inflated negative binomial model that included four local-scale habitat covariates (sea surface temperature, mean bottom depth, maximum bottom slope, and a variable to indicate if the segment was in a bay or not), one broad-scale covariate (the North Atlantic Oscillation), and a temporal correlation component. Our results indicate that species distributions have strong latitudinal gradients and consistency in local habitat use. The North Atlantic Oscillation was the only environmental covariate that had a significant (but variable) effect on the expected count for all five species, suggesting that broad-scale climatic conditions may be directly or indirectly important to the distributions of wintering sea ducks. Our results provide critical information on species-habitat associations, elucidate the complicated relationship between the North Atlantic Oscillation, sea surface temperature, and local sea duck abundances, and should be useful in assessing the impacts of climate

  2. Movements and foraging effort of Steller's Eiders and Harlequin Ducks wintering near Dutch Harbor, Alaska

    Science.gov (United States)

    Reed, J.A.; Flint, Paul L.

    2007-01-01

    We studied the movements and foraging effort of radio-marked Steller's Eiders (Polysticta stelleri) and Harlequin Ducks (Histrionicus histrionicus) to evaluate habitat quality in an area impacted by industrial activity near Dutch Harbor, Alaska. Foraging effort was relatively low, with Steller's Eiders foraging only 2.7 ± 0.6 (SE) hours per day and Harlequin Ducks 4.1 ± 0.5 hours per day. Low-foraging effort during periods of high-energetic demand generally suggests high food availability, and high food availability frequently corresponds with reductions in home range size. However, the winter ranges of Harlequin Ducks did not appear to be smaller than usual, with the mean range size in our study (5.5 ± 1.1 km2) similar to that reported by previous investigators. The mean size of the winter ranges of Steller's Eiders was similar (5.1 ± 1.3 km2), but no comparable estimates are available. Eutrophication of the waters near Dutch Harbor caused by seafood processing and municipal sewage effluent may have increased populations of the invertebrate prey of these sea ducks and contributed to their low-foraging effort. The threat of predation by Bald Eagles (Haliaeetus leucocephalus) that winter near Dutch Harbor may cause Steller's Eiders and Harlequin Ducks to move further offshore when not foraging, contributing to an increase in range sizes. Thus, the movement patterns and foraging behavior of these ducks likely represent a balance between the cost and benefits of wintering in a human-influenced environment.

  3. Increased body mass of ducks wintering in California's Central Valley

    Science.gov (United States)

    Fleskes, Joseph P.; Yee, Julie L.; Yarris, Gregory S.; Loughman, Daniel L.

    2016-01-01

    Waterfowl managers lack the information needed to fully evaluate the biological effects of their habitat conservation programs. We studied body condition of dabbling ducks shot by hunters at public hunting areas throughout the Central Valley of California during 2006–2008 compared with condition of ducks from 1979 to 1993. These time periods coincide with habitat increases due to Central Valley Joint Venture conservation programs and changing agricultural practices; we modeled to ascertain whether body condition differed among waterfowl during these periods. Three dataset comparisons indicate that dabbling duck body mass was greater in 2006–2008 than earlier years and the increase was greater in the Sacramento Valley and Suisun Marsh than in the San Joaquin Valley, differed among species (mallard [Anas platyrhynchos], northern pintail [Anas acuta], America wigeon [Anas americana], green-winged teal [Anas crecca], and northern shoveler [Anas clypeata]), and was greater in ducks harvested late in the season. Change in body mass also varied by age–sex cohort and month for all 5 species and by September–January rainfall for all except green-winged teal. The random effect of year nested in period, and sometimes interacting with other factors, improved models in many cases. Results indicate that improved habitat conditions in the Central Valley have resulted in increased winter body mass of dabbling ducks, especially those that feed primarily on seeds, and this increase was greater in regions where area of post-harvest flooding of rice and other crops, and wetland area, has increased. Conservation programs that continue to promote post-harvest flooding and other agricultural practices that benefit wintering waterfowl and continue to restore and conserve wetlands would likely help maintain body condition of wintering dabbling ducks in the Central Valley of California.

  4. Avian Influenza Ecology in North Atlantic Sea Ducks: Not All Ducks Are Created Equal

    Science.gov (United States)

    Hall, Jeffrey S.; Russell, Robin E.; Franson, J. Christian; Soos, Catherine; Dusek, Robert J.; Allen, R. Bradford; Nashold, Sean W.; TeSlaa, Joshua L.; Jónsson, Jón Eínar; Ballard, Jennifer R.; Harms, Naomi Jane; Brown, Justin D.

    2015-01-01

    Wild waterfowl are primary reservoirs of avian influenza viruses (AIV). However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61%) in these sea duck populations but low virus prevalence (0.3%). Using these data we estimated that an antibody half-life of 141 weeks (3.2 years) would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology. PMID:26677841

  5. Avian influenza ecology in North Atlantic sea ducks: Not all ducks are created equal

    Science.gov (United States)

    Hall, Jeffrey S.; Russell, Robin E.; Franson, J. Christian; Soos, Catherine; Dusek, Robert J.; Allen, R. Bradford; Nashold, Sean W.; Teslaa, Joshua L.; Jónsson, Jón Einar; Ballard, Jennifer R.; Harms, Naomi Jnae; Brown, Justin D.

    2015-01-01

    Wild waterfowl are primary reservoirs of avian influenza viruses (AIV). However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61%) in these sea duck populations but low virus prevalence (0.3%). Using these data we estimated that an antibody half-life of 141 weeks (3.2 years) would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology.

  6. Ecology and conservation of North American sea ducks

    Science.gov (United States)

    Savard, Jean-Pierre L.; Derksen, Dirk V.; Esler, Daniel N.; Eadie, John M.

    2015-01-01

    The past decade has seen a huge increase in the interest and attention directed toward sea ducks, the Mergini tribe. This has been inspired, in large part, by the conservation concerns associated with numerical declines in several sea duck species and populations, as well as a growing appreciation for their interesting ecological attributes. Reflecting the considerable research recently conducted on this tribe, Ecology and Conservation of North American Sea Ducks examines the 15 extant species of sea ducks from North America.

  7. Foraging flight distances of wintering ducks and geese: a review

    Directory of Open Access Journals (Sweden)

    William P. Johnson

    2014-12-01

    Full Text Available The distance covered by foraging animals, especially those that radiate from a central area when foraging, may affect ecosystem, community, and population dynamics, and has conservation and landscape planning implications for multiple taxa, including migratory waterfowl. Migrating and wintering waterfowl make regular foraging flights between roosting and feeding areas that can greatly impact energetic resources within the foraging zone near roost sites. We reviewed published studies and gray literature for one-way foraging flight distances (FFDs of migrating and wintering dabbling ducks and geese. Thirty reviewed studies reported FFDs and several reported values for multiple species or locations. We obtained FFD values for migration (n = 7 and winter (n = 70. We evaluated the effects of body mass, guild, i.e., dabbling duck or goose, and location, i.e., Nearctic or Palearctic, on FFDs. We used the second-order Akaike's Information Criterion for model selection. We found support for effects of location and guild on FFDs. FFDs of waterfowl wintering in the Nearctic (7.4 ± 6.7 km, mean ± SD; n = 39 values were longer than in the Palearctic (4.2 ± 3.2 km; n = 31 values. The FFDs of geese (7.8 ± 7.2 km, mean ± SD; n = 24 values were longer than FFDs of dabbling ducks (5.1 ± 4.4 km, mean ± SD; n = 46 values. We found mixed evidence that distance flown from the roost changed, i.e., increased or decreased, seasonally. Our results can be used to refine estimates of energetic carrying capacity around roosts and in biological and landscape planning efforts.

  8. Ducks change wintering patterns due to changing climate in the important wintering waters of the Odra River Estuary

    Directory of Open Access Journals (Sweden)

    Dominik Marchowski

    2017-07-01

    Full Text Available Some species of birds react to climate change by reducing the distance they travel during migration. The Odra River Estuary in the Baltic Sea is important for wintering waterfowl and is where we investigated how waterbirds respond to freezing surface waters. The most abundant birds here comprise two ecological groups: bottom-feeders and piscivores. Numbers of all bottom-feeders, but not piscivores, were negatively correlated with the presence of ice. With ongoing global warming, this area is increasing in importance for bottom-feeders and decreasing for piscivores. The maximum range of ice cover in the Baltic Sea has a weak and negative effect on both groups of birds. Five of the seven target species are bottom-feeders (Greater Scaup Aythya marila, Tufted Duck A. fuligula, Common Pochard A. ferina, Common Goldeneye Bucephala clangula and Eurasian Coot Fulica atra, and two are piscivores (Smew Mergellus albellus and Goosander Mergus merganser. Local changes at the level of particular species vary for different reasons. A local decline of the Common Pochard may simply be a consequence of its global decline. Climate change is responsible for some of the local changes in the study area, disproportionately favoring some duck species while being detrimental to others.

  9. Body-mass, survival, and pairing consequences of winter-diet restriction in wood ducks

    Science.gov (United States)

    Demarest, D.W.; Kaminski, R.M.; Brennan, L.A.; Boyle, C.R.

    1997-01-01

    We conducted feeding experiments with captive, wild-strain wood ducks (Aix sponsa) during winters 1990-91 and 1991-92 to test effects of increasing levels of food restriction on body mass dynamics, mortality, and pair formation. Male and female wood ducks fed restricted diets (i.e., 5, 10, 15, or 20% less food [g] than consumed on the previous day by a control group fed ad libitum) weighed less (P ??? 0.037) than birds fed ad libitum; those on 15 and 20% restricted diets weighed least. Increased mortality and decreased pair formation occurred only within the 20% restricted group (P ??? 0.049). We concluded that food restriction ranging between 15 and 20% of ad libitum intake may signify a threshold above which survival and reproduction of captive wood ducks may be impaired. Because energy costs of free living are greater than in captivity, a lower threshold may exist for wild wood ducks. Research is needed to validate the threshold theory for free-ranging wood ducks and other waterfowl, and to evaluate its potential application for conservation of winter foraging habitat. Conservation of bottomland hardwood ecosystems, which provide important foraging habitat for migrating and wintering wood ducks, should be encouraged to prevent potential negative effects on wood duck life-cycle events.

  10. Mid-winter European dabbling duck distributions are not linked to species body mass

    DEFF Research Database (Denmark)

    Dalby, Lars; Delany, Simon; Fox, Anthony David

    are likely to play a major role in determining the wintering distribution of short- to medium-distance migratory bird species and its inter-annual variability. As avian thermoregulatory costs scale allometrically with body size, we predicted that the mean mid-winter temperature experienced by six species...... of dabbling ducks wintering in Western Europe would be negatively correlated with body mass. We found no evidence for such a relationship in a large-scale analysis testing for a link between temperature and dabbling duck distributions, suggesting that other factors such as those related to feeding ecology......In order to understand the current changes and to predict future changes in wintering dabbling duck (Anas sp.) distributions in response to climate change, it is important to understand how species distribute themselves on a continental scale in response to temperature. Thermoregulatory costs...

  11. Impact Assessment of an Off-Shore Wind Park on Sea Ducks

    DEFF Research Database (Denmark)

    Guillemette, M.; Larsen, J. K.; Clausager, I.

    of the study with a marked difference between Tunø Knob and Ringebjerg Sand in the size available. This was associated with a general impoverishment of the whole benthic community. This suggests that the decrease observed in sea duck abundance over the three years was caused by the availability of food supply......As part of the plan of the Danish government to expand off-shore wind energy production, The Ministry of Environment and Energy, in collaboration with ELSAM (an energy consortium), initiated a three-year study of the potential conflict between the Tunø Knob off-shore wind park and aquatic birds...... in 1994-97. Danish coastal waters support very large, internationally important concentrations of moulting, migrating and wintering sea ducks which depend on shallow water areas as major feeding habitats. Denmark is committed, in relation to international conventions and EU directives, to protect...

  12. Assessing the Impact of the Tunø Knob Wind Park on Sea Ducks : the Influence of Food Resources

    DEFF Research Database (Denmark)

    Guillemette, M.; Larsen, J. K.; Clausager, I.

    Abstract This study deals with the influence of benthos abundance when assessing the potential impact of a small wind park on wintering sea ducks. Using the Before-After-Control-Impact design, it was suggested in a recent study (Guillemette et al. 1998) that the wind park provoked a decline...... at Tunø Knob to test the hypothesis that, if food abundance increases again, we should also observe an increase in duck abundance. The methods used in this study are similar to those applied in the aforementioned study. The results showed that the average number of common eiders increased considerably...... in the abundance and a change in the distribution of common eiders Somateria mollissima and common scoters Melanitta nigra. However, the observed decline in sea duck abundance occurred con-comitantly with a decline of benthic food supplies. We measured con-comitant food and common eider abundance for a fourth year...

  13. Estimation and correction of visibility bias in aerial surveys of wintering ducks

    Science.gov (United States)

    Pearse, A.T.; Gerard, P.D.; Dinsmore, S.J.; Kaminski, R.M.; Reinecke, K.J.

    2008-01-01

    Incomplete detection of all individuals leading to negative bias in abundance estimates is a pervasive source of error in aerial surveys of wildlife, and correcting that bias is a critical step in improving surveys. We conducted experiments using duck decoys as surrogates for live ducks to estimate bias associated with surveys of wintering ducks in Mississippi, USA. We found detection of decoy groups was related to wetland cover type (open vs. forested), group size (1?100 decoys), and interaction of these variables. Observers who detected decoy groups reported counts that averaged 78% of the decoys actually present, and this counting bias was not influenced by either covariate cited above. We integrated this sightability model into estimation procedures for our sample surveys with weight adjustments derived from probabilities of group detection (estimated by logistic regression) and count bias. To estimate variances of abundance estimates, we used bootstrap resampling of transects included in aerial surveys and data from the bias-correction experiment. When we implemented bias correction procedures on data from a field survey conducted in January 2004, we found bias-corrected estimates of abundance increased 36?42%, and associated standard errors increased 38?55%, depending on species or group estimated. We deemed our method successful for integrating correction of visibility bias in an existing sample survey design for wintering ducks in Mississippi, and we believe this procedure could be implemented in a variety of sampling problems for other locations and species.

  14. Correlates of Harlequin Duck densities during winter in Prince William Sound, Alaska

    Science.gov (United States)

    Esler, Daniel N.; Bowman, Timothy D.; Dean, T.A.; O'Clair, Charles E.; Jewett, S.C.; McDonald, L.L.

    2000-01-01

    We evaluated relationships of Harlequin Duck (Histrionicus histrionicus) densities to habitat attributes, history of habitat contamination by the 1989 Exxon Valdez oil spill, and prey biomass density and abundance during winters 1995-1997 in Prince William Sound, Alaska. Habitat features that explained variation in duck densities included distance to streams and reefs, degree of exposure to wind and wave action, and dominant substrate type. After accounting for these effects, densities were lower in oiled than unoiled areas, suggesting that population recovery from the oil spill was not complete, due either to lack of recovery from initial oil spill effects or continuing deleterious effects. Prey biomass density and abundance were not strongly related to duck densities after accounting for habitat and area effects. Traits of Harlequin Ducks that reflect their affiliation with naturally predictable winter habitats, such as strong site fidelity and intolerance of increased energy costs, may make their populations particularly vulnerable to chronic oil spill effects and slow to recover from population reductions, which may explain lower densities than expected on oiled areas nearly a decade following the oil spill.

  15. Winter cooling in the northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Prasad, T.G.

    forcing that leads to the observed high productivity during winter in the northern Arabian Sea. The weak northerly winds and increased solar insolation during the inter-monsoon period, led to the development of a highly stratified upper layer with warm sea...

  16. Use of no-till winter wheat by nesting ducks in North Dakota

    Science.gov (United States)

    Duebbert, H.F.; Kantrud, H.A.

    1987-01-01

    Nesting of dabbling ducks (Anatinae) was studied in fields of no-till winter wheat (Triticum aestivum) in the prairie pothole region of North Dakota during 1984 and 1985. Total area of 59 fields searched in 1984 was 1,135 ha and total area of 70 fields searched in 1985 was 1,175 ha. Field sizes ranged from 3 ha to 110 ha. Nests of five duck species were found: blue-winged teal (Anas discors), 55 nests; northern pintail (A. acuta), 44; mallard (A. platyrhynchos), 29; gadwall (A. strepera), 15; and northern shoveler (A. clypeata), 8. The average number of nests found was 8/100 ha in 1984 and 6/100 ha in 1985. Nest success for all species averaged 26% in 1984 and 29% in 1985. Predation by mammals was the principal cause of nest destruction. No egg or hen mortality could be attributed to pesticide use. Only 6 of 151 nests (4%) were abandoned during the two years. We also found 29 nests of seven other ground-nesting bird species. The trend toward increased planting of no-till winter wheat in the prairie pothole region should benefit production of ducks and other ground-nesting birds.

  17. Assessing the impact of the Tunoe Knob wind park on sea ducks: the influence of food resources

    International Nuclear Information System (INIS)

    Laursen, K.; Guillemette, M.; Kyed larsen, J.; Clausager, I.

    1999-02-01

    This study deals with the influence of benthos abundance when assessing the potential impact of a small wind park on wintering sea ducks. Using the Before-After-Control-Impact design, it was suggested in a recent study that the wind park provoked a decline in the abundance and a change in the distribution of common eiders Somateria mollissima and common scoters Melanitta nigra. However, the observed decline in sea duck abundance occurred concomitantly with a decline of benthic food supplies. We measured concomitant food and common eider abundance for a fourth year at Tunoe Knob to test the hypothesis that, if food abundance increases again, we should also observe an increase in duck abundance. The methods used in this study are similar to those applied in the aforementioned study. The results showed that the average number of common eiders increased considerably in 1997-98 (3,361 individuals) compared to 1996-97 (458), even surpassing the level observed during the baseline years in 1994-95 (1,821). A significant increase in the abundance of common scoters occurred in 1997-98 compared to 1995-96 and 1996-97, but not in relation to the baseline year. The abundance of food for sea ducks also increased in 1997-98 where the frequency of occurrence of most potential prey reached the level observed during the baseline year. The density of blue mussels, a preferred prey species, was 1,113 individuals m -2 in 1997-98 compared to 11,111 individuals m -2 during the baseline year and only 100 individuals m -2 in 1996-97. Computations of the amount of food supply eaten by wintering common eiders suggest that, during the baseline year, prey were superabundant. This may explain why we observed a great abundance of common eiders in 1997-98 despite the fact that mussel abundance did not reach the level observed during the baseline year. Finally, the distribution of common eiders in 1997-98 on the study site as a whole was very similar to the distribution observed during the

  18. Body mass, wing length, and condition of wintering ducks relative to hematozoa infection

    Science.gov (United States)

    Fleskes, Joseph; Ramey, Andrew M.; Reeves, Andrew; Yee, Julie L.

    2017-01-01

    Waterfowl managers lack information regarding factors that may be reducing the positive response of waterfowl body condition to habitat improvements. Protozoan blood parasites (i.e., hematozoa) are commonly found in birds and have been related to reduced body mass, wing length, and body condition. We studied relationships between 12 measures of hematozoa infection and body mass, wing length, and body mass divided by wing length (i.e., body condition index [BCI]) of the five most common duck species (northern pintail [Anas acuta], mallard [A. platyrhynchos], green-winged teal [A. crecca], American wigeon [A. Americana], northern shoveler [A. clypeata]) wintering in the Central Valley of California during October 2006-January 2007. After accounting for variation due to species, age-sex cohort, Central Valley region, and month; wing length, body mass, and BCI were found to be negatively related to infection by Leucocytozoon and by "any hematozoa" but not related to infection by only Plasmodium or Haemoproteus, or coinfections of greater than one genera or parasite haplotype (albeit, few ducks had Plasmodium or Haemoproteus infection or coinfections). Evidence of a negative relationship with infection was stronger for body mass and BCI than for wing length and indicated that the relationships varied among species, age-sex cohorts, regions, and months. Compared to uninfected ducks, hematozoa-infected duck body mass, wing length, and BCI was -1.63% (85% CI = -2.79%- -0.47%), -0.12% (-0.41%- +0.17%), and -1.38% (-2.49%- -0.26%), respectively. Although, seemingly small, the -1.63% difference in body mass represents a large percentage (e.g., 38% for northern pintail) of the observed increase in wintering duck body mass associated with Central Valley habitat improvements. Because infection prevalence and relationship to body condition might change over time due to climate or other factors, tracking hematozoa infection prevalence might be important to inform and accurately

  19. Intermittent fasting during winter and spring affects body composition and reproduction of a migratory duck

    Science.gov (United States)

    Barboza, P.S.; Jorde, Dennis G.

    2002-01-01

    We compared food intake, body mass and body composition of male and female black ducks (Anas rubripes) during winter (January-March). Birds were fed the same complete diet ad libitum on consecutive days each week without fasting (control; nine male; nine female) or with either short fasts (2 day.week-1; nine male; nine female), or long fasts (4 day.week-1; eleven male; twelve female). We continued treatments through spring (March-May) to measure the effect of intermittent fasts on body mass and egg production. Daily food intake of fasted birds was up to four times that of unfasted birds. Weekly food intake of males was similar among treatments (364 g.kg-1.week-1) but fasted females consumed more than unfasted females in January (363 g.kg-1.week-1 vs. 225 g.kg-1.week-1). Although both sexes lost 10-14% body mass, fasted females lost less mass and lipid than unfasted females during winter. Total body nitrogen was conserved over winter in both sexes even though the heart and spleen lost mass while the reproductive tract and liver gained mass. Intermittent fasting increased liver, intestinal tissue and digesta mass of females but not of males. Fasting delayed egg production in spring but did not affect size, fertility or hatching of the clutch. Females on long fasts were still heavier than controls after laying eggs. Thus black ducks combine flexibility of food intake with plasticity of digestive tract, liver and adipose tissue when food supply is interrupted during winter. Females modulate body mass for survival and defer reproduction when food supply is interrupted in spring.

  20. Infectious diseases, parasites, and biological toxins in sea ducks: Chapter 4

    Science.gov (United States)

    Hollmén, Tuula E.; Franson, J. Christian

    2015-01-01

    This chapter addresses disease agents in the broad sense, including viruses, bacteria, fungi, protozoan and helminth parasites, and biological toxins. Some of these agents are known to cause mortality in sea ducks, some are thought to be incidental findings, and the significance of others is yet poorly understood. Although the focus of the chapter is on free-living sea ducks, the study of disease in this taxonomic group has been relatively limited and examples from captive sea ducks and other wild waterfowl are used to illustrate the pathogenicity of certain diseases. Much of the early work in sea ducks consisted of anecdotal and descriptive reports of parasites, but it was soon recognized that diseases such as avian cholera, renal coccidiosis, and intestinal infections with acanthocephalans were causes of mortality in wild populations. More recently, adenoviruses, reoviruses, and the newly emergent Wellfleet Bay virus, for example, also have been linked to die-offs of sea ducks. Declining populations of animals are particularly vulnerable to the threats posed by disease and it is important that we improve our understanding of the significance of disease in sea ducks. To conclude, we offer our recommendations for future directions in this field.

  1. Impact assessment of an off-shore wind park on sea ducks

    International Nuclear Information System (INIS)

    Guillemette, M.; Kyed Larsen, J.; Clausager, I.

    1998-03-01

    As part of the plan of the Danish government to expand off-shore wind energy production, The Ministry of Environment and Energy, in collaboration with ELSAM (an energy consortium), initiated a three-year study of the potential conflict between the Tunoe Knob off-shore wind park and aquatic birds in 1994-97. Danish coastal waters support very large, internationally important concentrations of moulting, migrating and wintering sea ducks which depend on shallow water areas as major feeding habitats. Denmark is committed, in relation to international conventions and EU directives, to protect and maintain these populations of aquatic birds and such shallow coastal areas are precisely the type of areas in which future wind parks are planned. Two general approaches were adopted for the investigation: the before-after-control-impact design (BACI) and After studies conducted around the wind park. The aim of the BACI studies was to compare bird abundance and distribution before and after the construction of the wind park and between the area presumably affected by the development and a control area. This was carried out on three spatial scales: (i) conducting aerial surveys in two large zones (about 5,000 ha), Tunoe Knob and Ringebjerg Sand, while controlling the total number of birds in Aarhus Bay (88,000 ha), (ii) conducting ground surveys of two areas of about 700-800 ha coverage at Tunoe Knob and Ringebjerg Sand, using the latter as a control area and (iii) within Tunoe using three sub areas (160-250 ha) as controls compared to the construction area. The after experiments were conducted around the wind park with the aim of controlling the confounding effect of food supply and to establish (a) the short-term possible effects of noise and rotor movements generated by the turbines on the distribution and abundance of sea ducks and (b) the long-term scaring effect of the wind park (the impact of revolving rotors and the presence of the standing towers). Finally, an

  2. Evaluation of harvest and information needs for North American sea ducks.

    Science.gov (United States)

    Koneff, Mark D; Zimmerman, Guthrie S; Dwyer, Chris P; Fleming, Kathleen K; Padding, Paul I; Devers, Patrick K; Johnson, Fred A; Runge, Michael C; Roberts, Anthony J

    2017-01-01

    Wildlife managers routinely seek to establish sustainable limits of sport harvest or other regulated forms of take while confronted with considerable uncertainty. A growing body of ecological research focuses on methods to describe and account for uncertainty in management decision-making and to prioritize research and monitoring investments to reduce the most influential uncertainties. We used simulation methods incorporating measures of demographic uncertainty to evaluate risk of overharvest and prioritize information needs for North American sea ducks (Tribe Mergini). Sea ducks are popular game birds in North America, yet they are poorly monitored and their population dynamics are poorly understood relative to other North American waterfowl. There have been few attempts to assess the sustainability of harvest of North American sea ducks, and no formal harvest strategy exists in the U.S. or Canada to guide management. The popularity of sea duck hunting, extended hunting opportunity for some populations (i.e., special seasons and/or bag limits), and population declines have led to concern about potential overharvest. We used Monte Carlo simulation to contrast estimates of allowable harvest and observed harvest and assess risk of overharvest for 7 populations of North American sea ducks: the American subspecies of common eider (Somateria mollissima dresseri), eastern and western populations of black scoter (Melanitta americana) and surf scoter (M. perspicillata), and continental populations of white-winged scoter (M. fusca) and long-tailed duck (Clangula hyemalis). We combined information from empirical studies and the opinions of experts through formal elicitation to create probability distributions reflecting uncertainty in the individual demographic parameters used in this assessment. Estimates of maximum growth (rmax), and therefore of allowable harvest, were highly uncertain for all populations. Long-tailed duck and American common eider appeared to be at high

  3. A blood survey of elements, viral antibodies, and hemoparasites in wintering Harlequin Ducks (Histrionicus histrionicus) and Barrow's Goldeneyes (Bucephala islandica).

    Science.gov (United States)

    Heard, Darryl J; Mulcahy, Daniel M; Iverson, Samuel A; Rizzolo, Daniel J; Greiner, Ellis C; Hall, Jeff; Ip, Hon; Esler, Daniel

    2008-04-01

    Twenty-eight Harlequin Ducks (Histrionicus histrionicus) and 26 Barrow's Goldeneyes (Bucephala islandica) were captured in Prince William Sound, Alaska, between 1 and 15 March 2005. Blood was collected for quantification of element concentrations, prevalence of antibodies to several viruses, and hemoparasite prevalence and identification. Although we found selenium concentrations that have been associated with selenosis in some birds (>or=2.0 ppm ww), our findings contribute to a growing literature describing relatively high selenium in apparently healthy birds in marine environments. Avian influenza virus antibodies were detected in the plasma of 28% of the ducks. No antibodies against adenovirus, reovirus, or paramyxovirus 1 were detected. Several hemo-parasite species were identified in 7% of ducks. Our findings are similar to those in other free-living marine waterfowl and do not indicate unusual concerns for the health of these species in this area in late winter.

  4. Molecular typing of Escherichia coli strains associated with threatened sea ducks and near-shore marine habitats of south-west Alaska

    Science.gov (United States)

    Hollmén, Tuula E.; DebRoy, Chitrita; Flint, Paul L.; Safine, David E.; Schamber, Jason L.; Riddle, Ann E.; Trust, Kimberly A.

    2011-01-01

    In Alaska, sea ducks winter in coastal habitats at remote, non-industrialized areas, as well as in proximity to human communities and industrial activity. We evaluated prevalence and characteristics of Escherichia coli strains in faecal samples of Steller's eiders (Polysticta stelleri; n = 122) and harlequin ducks (Histrionicus histrionicus; n = 21) at an industrialized site and Steller's eiders (n = 48) at a reference site, and compared these strains with those isolated from water samples from near-shore habitats of ducks. The overall prevalence of E. coli was 16% and 67% in Steller's eiders and harlequin ducks, respectively, at the industrialized study site, and 2% in Steller's eiders at the reference site. Based on O and H antigen subtyping and genetic characterization by enterobacterial repetitive intergenic consensus polymerase chain reaction and pulsed-field gel electrophoresis, we found evidence of avian pathogenic E. coli (APEC) strains associated with both species and detected E. coli strains carrying virulence genes associated with mammals in harlequin ducks. Steller's eiders that carried APEC had lower serum total protein and albumin concentrations, providing further evidence of pathogenicity. The genetic profile of two E. coli strains from water matched an isolate from a Steller's eider providing evidence of transmission between near-shore habitats and birds.

  5. Molecular typing of Escherichia coli strains associated with threatened sea ducks and near-shore marine habitats of south-west Alaska.

    Science.gov (United States)

    Hollmén, Tuula E; Debroy, Chitrita; Flint, Paul L; Safine, David E; Schamber, Jason L; Riddle, Ann E; Trust, Kimberly A

    2011-04-01

    In Alaska, sea ducks winter in coastal habitats at remote, non-industrialized areas, as well as in proximity to human communities and industrial activity. We evaluated prevalence and characteristics of Escherichia coli strains in faecal samples of Steller's eiders (Polysticta stelleri; n = 122) and harlequin ducks (Histrionicus histrionicus; n = 21) at an industrialized site and Steller's eiders (n = 48) at a reference site, and compared these strains with those isolated from water samples from near-shore habitats of ducks. The overall prevalence of E. coli was 16% and 67% in Steller's eiders and harlequin ducks, respectively, at the industrialized study site, and 2% in Steller's eiders at the reference site. Based on O and H antigen subtyping and genetic characterization by enterobacterial repetitive intergenic consensus polymerase chain reaction and pulsed-field gel electrophoresis, we found evidence of avian pathogenic E. coli (APEC) strains associated with both species and detected E. coli strains carrying virulence genes associated with mammals in harlequin ducks. Steller's eiders that carried APEC had lower serum total protein and albumin concentrations, providing further evidence of pathogenicity. The genetic profile of two E. coli strains from water matched an isolate from a Steller's eider providing evidence of transmission between near-shore habitats and birds. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  6. The status of sea ducks in the North Pacific Rim: Toward their conservation and management

    Science.gov (United States)

    Goudie, R. Ian; Brault, Solange; Conant, Bruce; Kondratyev, Alexander V.; Petersen, Margaret R.; Vermeer, Kees; McCabe, Richard E.; Wadsworth, Kelly G.

    1994-01-01

    Sea ducks (tribe Mergini after Johnsgard 1960) are the most northerly distributed ducks, and species diversity is greatest in the North Pacific. They exploit a diversity of inshore and offshore marine habitats during the non-breeding season, and their use of habitat during breeding varies from coastal through freshwater wetlands of the tundra and taiga (Figure 1, Appendix 1). Non-breeding cohorts frequent marine habitats most of the year. Sea ducks thus are important indicators of the quality of freshwater and marine ecosystems of northern biomes.Of the 17 species discussed in this manuscript, at least 3 are reported to be declining (Appendix 2). However, the basis for many of those assessments is equivocal because there has been little effort to monitor populations. The efforts to more precisely assess their status point to catastrophic declines (Kertell 1991, Stehn et a 1993). Conservation problems related to sea ducks have a long history throughout the Holarctic. For example, the Labrador duck (Camptorhynchus labradorius) became extinct in 1875. (Phillips 1925); common eiders (Somateria mollissima) declined seriously throughout the northern hemisphere (Townsend 1914, Phillips 1925, Doughty 1979); harlequin ducks (Histrionicus histrionicus) experienced declines in Iceland and Greenland (Gudmundsson1971, Salomonson 1950), and more recently have been designated endangered in eastern Canada (Committee On the Status of Endangered Wildlife in Canada 1990). In Russia, all species of eider and harlequin ducks have been closed to sport hunting since 1981, and the Chinese mergansers (Mergus squamatus) presently are extremely rare and fully protected, i.e. category one of the red book (Solomonov 1987).

  7. Monitoring responses to variation in food supply for a migratory waterfowl: American Black Duck (Anas rubripes) in winter.

    Science.gov (United States)

    Barboza, Perry S; Jorde, Dennis G

    2018-05-26

    Wintering Black Ducks (Anas rubripes) concentrate in wetlands along the Atlantic coast where natural and anthropogenic disturbances have increased over the last 50 years, a period in which the population of Black Ducks has declined. We studied the sensitivity of Black Ducks to perturbations in food supply that often result from disturbances by storms, predators, and people. In the paper, we characterize the responses of captive Black Ducks to shifts in food quality and availability during winter and apply those measures to a comparison of wild birds. Captive ducks that were fed intermittently (3 consecutive days/week) compensated for fasted days to achieve similar body mass and body fat to control birds that were fed every day on both animal- and plant-based diets. However, birds that were fed intermittently expended 15% more energy each day than controls when both groups were fed (536 vs. 464 kJ/kg 0.75 ), which indicates that variable food supply increases the costs of maintenance and thus reduces the number of birds that can be supported on the same resource of food without interruptions to foraging. Egg production was not affected by diet quality provided in spring or by the frequency of feeding during the preceding winter months. Black Ducks lost body fat through winter in captivity and in the wild. Fat stores of birds in New Jersey were greater than those of birds in Maine (13.3 vs. 8.3% of body mass) in January, which reflected the high energy demands of cold temperatures in Maine. Values for ∂ 15 N were greater in Maine than in New Jersey for both red blood cells and plasma, which indicated a consistent diet of marine invertebrates in Maine. Greater isotopic variation in red blood cells indicated that diets were more diverse in New Jersey than in Maine for both ∂ 15 N (9.7 ± 1.1 vs. 11.2 ± 0.4‰) and for ∂ 13 C (- 15.1 ± 2.2 vs. - 13.8 ± 1.4‰). Plasma ∂ 13 C was enriched over red blood cells in wild birds especially those

  8. PCB exposure in sea otters and harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill

    Science.gov (United States)

    Ricca, Mark A.; Miles, A. Keith; Ballachey, Brenda E.; Bodkin, James L.; Esler, Daniel N.; Trust, Kimberly A.

    2010-01-01

    Exposure to contaminants other than petroleum hydrocarbons could confound interpretation of Exxon Valdez oil spill effects on biota at Prince William Sound, Alaska. Hence, we investigated polychlorinated biphenyls (PCBs) in blood of sea otters and harlequin ducks sampled during 1998. PCB concentrations characterized by lower chlorinated congeners were highest in sea otters from the unoiled area, whereas concentrations were similar among harlequin ducks from the oiled and unoiled area. Blood enzymes often elevated by xenobiotics were not related to PCB concentrations in sea otters. Only sea otters from the unoiled area had estimated risk from PCBs, and PCB composition or concentrations did not correspond to reported lower measures of population performance in sea otters or harlequin ducks from the oiled area. PCBs probably did not influence limited sea otter or harlequin duck recovery in the oiled area a decade after the spill.

  9. Effects of predation by sea ducks on clam abundance in soft-bottom intertidal habitats

    Science.gov (United States)

    Lewis, Tyler; Esler, Daniel N.; Boyd, W. Sean

    2007-01-01

    Recent studies have documented strong, top-down predation effects of sea ducks on mussel populations in rocky intertidal communities. However, the impact of these gregarious predators in soft-bottom communities has been largely unexplored. We evaluated effects of predation by wintering surf scoters Melanitta perspicillata and white-winged scoters M. fusca on clam populations in soft-bottom intertidal habitats of the Strait of Georgia, British Columbia. Specifically, we documented spatial and temporal variation in clam density (clams m–2), scoter diet composition, and the consequences of scoter predation on clam abundance. Of the 3 most numerous clams, Manila clams Venerupis philippinarum and varnish clams Nuttallia obscurata were the primary prey items of both scoter species, while clams of the genus Macoma were rarely consumed by scoters. Between scoter arrival in the fall and departure in the spring, Manila clams decreased in density at most sample sites, while varnish clam densities did not change or declined slightly. Our estimates of numbers of clams consumed by scoters accounted for most of the observed declines in combined abundance of Manila and varnish clams, despite the presence of numerous other vertebrate and invertebrate species known to consume clams. For Macoma spp., we detected an over-winter increase in density, presumably due to growth of clams too small to be retained by our sieve (<5 mm) during fall sampling, in addition to the lack of predation pressure by scoters. These results illustrate the strong predation potential of scoters in soft-bottom intertidal habitats, as well as their potentially important role in shaping community structure.

  10. Seasonal overturning circulation in the Red Sea: 2. Winter circulation

    KAUST Repository

    Yao, Fengchao; Hoteit, Ibrahim; Pratt, Lawrence J.; Bower, Amy S.; Kö hl, Armin; Gopalakrishnan, Ganesh; Rivas, David

    2014-01-01

    The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented

  11. Nitrogen uptake in the northeastern Arabian Sea during winter cooling

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, S.; Ramesh, R.; Dwivedi, R.M.; Raman, M.; Sheshshayee, M.S.; DeSouza, W.

    /plain; charset=UTF-8 Hindawi Publishing Corporation International Journal of Oceanography Volume 2010, Article ID 819029, 11 pages doi:10.1155/2010/819029 Research Article Nitrogen Uptake in the Northeastern Arabian Sea during Winter Cooling S. Kumar, 1...

  12. Evaluation of harvest and information needs for North American sea ducks

    Science.gov (United States)

    Koneff, Mark D.; Zimmerman, Guthrie S.; Dwyer, Chris P.; Fleming, Kathleen K.; Padding, Paul I.; Devers, Patrick K.; Johnson, Fred A.; Runge, Michael C.; Roberts, Anthony J.

    2017-01-01

    Wildlife managers routinely seek to establish sustainable limits of sport harvest or other regulated forms of take while confronted with considerable uncertainty. A growing body of ecological research focuses on methods to describe and account for uncertainty in management decision-making and to prioritize research and monitoring investments to reduce the most influential uncertainties. We used simulation methods incorporating measures of demographic uncertainty to evaluate risk of overharvest and prioritize information needs for North American sea ducks (Tribe Mergini). Sea ducks are popular game birds in North America, yet they are poorly monitored and their population dynamics are poorly understood relative to other North American waterfowl. There have been few attempts to assess the sustainability of harvest of North American sea ducks, and no formal harvest strategy exists in the U.S. or Canada to guide management. The popularity of sea duck hunting, extended hunting opportunity for some populations (i.e., special seasons and/or bag limits), and population declines have led to concern about potential overharvest. We used Monte Carlo simulation to contrast estimates of allowable harvest and observed harvest and assess risk of overharvest for 7 populations of North American sea ducks: the American subspecies of common eider (Somateria mollissima dresseri), eastern and western populations of black scoter (Melanitta americana) and surf scoter (M. perspicillata), and continental populations of white-winged scoter (M. fusca) and long-tailed duck (Clangula hyemalis). We combined information from empirical studies and the opinions of experts through formal elicitation to create probability distributions reflecting uncertainty in the individual demographic parameters used in this assessment. Estimates of maximum growth (rmax), and therefore of allowable harvest, were highly uncertain for all populations. Long-tailed duck and American common eider appeared to be at high

  13. Evaluation of harvest and information needs for North American sea ducks.

    Directory of Open Access Journals (Sweden)

    Mark D Koneff

    Full Text Available Wildlife managers routinely seek to establish sustainable limits of sport harvest or other regulated forms of take while confronted with considerable uncertainty. A growing body of ecological research focuses on methods to describe and account for uncertainty in management decision-making and to prioritize research and monitoring investments to reduce the most influential uncertainties. We used simulation methods incorporating measures of demographic uncertainty to evaluate risk of overharvest and prioritize information needs for North American sea ducks (Tribe Mergini. Sea ducks are popular game birds in North America, yet they are poorly monitored and their population dynamics are poorly understood relative to other North American waterfowl. There have been few attempts to assess the sustainability of harvest of North American sea ducks, and no formal harvest strategy exists in the U.S. or Canada to guide management. The popularity of sea duck hunting, extended hunting opportunity for some populations (i.e., special seasons and/or bag limits, and population declines have led to concern about potential overharvest. We used Monte Carlo simulation to contrast estimates of allowable harvest and observed harvest and assess risk of overharvest for 7 populations of North American sea ducks: the American subspecies of common eider (Somateria mollissima dresseri, eastern and western populations of black scoter (Melanitta americana and surf scoter (M. perspicillata, and continental populations of white-winged scoter (M. fusca and long-tailed duck (Clangula hyemalis. We combined information from empirical studies and the opinions of experts through formal elicitation to create probability distributions reflecting uncertainty in the individual demographic parameters used in this assessment. Estimates of maximum growth (rmax, and therefore of allowable harvest, were highly uncertain for all populations. Long-tailed duck and American common eider appeared

  14. Changes in size and trends of North American sea duck populations associated with North Pacific oceanic regime shifts

    Science.gov (United States)

    Flint, Paul L.

    2013-01-01

    Broad-scale multi-species declines in populations of North American sea ducks for unknown reasons is cause for management concern. Oceanic regime shifts have been associated with rapid changes in ecosystem structure of the North Pacific and Bering Sea. However, relatively little is known about potential effects of these changes in oceanic conditions on marine bird populations at broad scales. I examined changes in North American breeding populations of sea ducks from 1957 to 2011 in relation to potential oceanic regime shifts in the North Pacific in 1977, 1989, and 1998. There was strong support for population-level effects of regime shifts in 1977 and 1989, but little support for an effect of the 1998 shift. The continental-level effects of these regime shifts differed across species groups and time. Based on patterns of sea duck population dynamics associated with regime shifts, it is unclear if the mechanism of change relates to survival or reproduction. Results of this analysis support the hypothesis that population size and trends of North American sea ducks are strongly influenced by oceanic conditions. The perceived population declines appear to have halted >20 years ago, and populations have been relatively stable or increasing since that time. Given these results, we should reasonably expect dramatic changes in sea duck population status and trends with future oceanic regime shifts.

  15. Hydrographic features of the Lakshadweep (Laccadives) sea during winter

    Digital Repository Service at National Institute of Oceanography (India)

    Das, V.K.

    Hydrographic features of the Lakshadweep Sea during winter have been studied using the data collected in December during the 13th cruise of R.V. Gaveshani. The mixed layer depth in this region varies between 30 and 70 m. The thickness...

  16. Comparative population structure of cavity-nesting sea ducks

    Science.gov (United States)

    Pearce, John M.; Eadie, John M.; Savard, Jean-Pierre L.; Christensen, Thomas K.; Berdeen, James; Taylor, Eric J.; Boyd, Sean; Einarsson, Árni

    2014-01-01

    A growing collection of mtDNA genetic information from waterfowl species across North America suggests that larger-bodied cavity-nesting species exhibit greater levels of population differentiation than smaller-bodied congeners. Although little is known about nest-cavity availability for these species, one hypothesis to explain differences in population structure is reduced dispersal tendency of larger-bodied cavity-nesting species due to limited abundance of large cavities. To investigate this hypothesis, we examined population structure of three cavity-nesting waterfowl species distributed across much of North America: Barrow's Goldeneye (Bucephala islandica), Common Goldeneye (B. clangula), and Bufflehead (B. albeola). We compared patterns of population structure using both variation in mtDNA control-region sequences and band-recovery data for the same species and geographic regions. Results were highly congruent between data types, showing structured population patterns for Barrow's and Common Goldeneye but not for Bufflehead. Consistent with our prediction, the smallest cavity-nesting species, the Bufflehead, exhibited the lowest level of population differentiation due to increased dispersal and gene flow. Results provide evidence for discrete Old and New World populations of Common Goldeneye and for differentiation of regional groups of both goldeneye species in Alaska, the Pacific Northwest, and the eastern coast of North America. Results presented here will aid management objectives that require an understanding of population delineation and migratory connectivity between breeding and wintering areas. Comparative studies such as this one highlight factors that may drive patterns of genetic diversity and population trends.

  17. Loss of sea ice during winter north of Svalbard

    Directory of Open Access Journals (Sweden)

    Ingrid H. Onarheim

    2014-06-01

    Full Text Available Sea ice loss in the Arctic Ocean has up to now been strongest during summer. In contrast, the sea ice concentration north of Svalbard has experienced a larger decline during winter since 1979. The trend in winter ice area loss is close to 10% per decade, and concurrent with a 0.3°C per decade warming of the Atlantic Water entering the Arctic Ocean in this region. Simultaneously, there has been a 2°C per decade warming of winter mean surface air temperature north of Svalbard, which is 20–45% higher than observations on the west coast. Generally, the ice edge north of Svalbard has retreated towards the northeast, along the Atlantic Water pathway. By making reasonable assumptions about the Atlantic Water volume and associated heat transport, we show that the extra oceanic heat brought into the region is likely to have caused the sea ice loss. The reduced sea ice cover leads to more oceanic heat transferred to the atmosphere, suggesting that part of the atmospheric warming is driven by larger open water area. In contrast to significant trends in sea ice concentration, Atlantic Water temperature and air temperature, there is no significant temporal trend in the local winds. Thus, winds have not caused the long-term warming or sea ice loss. However, the dominant winds transport sea ice from the Arctic Ocean into the region north of Svalbard, and the local wind has influence on the year-to-year variability of the ice concentration, which correlates with surface air temperatures, ocean temperatures, as well as the local wind.

  18. Winter sea ice export from the Laptev Sea preconditions the local summer sea ice cover and fast ice decay

    Directory of Open Access Journals (Sweden)

    P. Itkin

    2017-10-01

    Full Text Available Ice retreat in the eastern Eurasian Arctic is a consequence of atmospheric and oceanic processes and regional feedback mechanisms acting on the ice cover, both in winter and summer. A correct representation of these processes in numerical models is important, since it will improve predictions of sea ice anomalies along the Northeast Passage and beyond. In this study, we highlight the importance of winter ice dynamics for local summer sea ice anomalies in thickness, volume and extent. By means of airborne sea ice thickness surveys made over pack ice areas in the south-eastern Laptev Sea, we show that years of offshore-directed sea ice transport have a thinning effect on the late-winter sea ice cover. To confirm the preconditioning effect of enhanced offshore advection in late winter on the summer sea ice cover, we perform a sensitivity study using a numerical model. Results verify that the preconditioning effect plays a bigger role for the regional ice extent. Furthermore, they indicate an increase in volume export from the Laptev Sea as a consequence of enhanced offshore advection, which has far-reaching consequences for the entire Arctic sea ice mass balance. Moreover we show that ice dynamics in winter not only preconditions local summer ice extent, but also accelerate fast-ice decay.

  19. Seasonal overturning circulation in the Red Sea: 2. Winter circulation

    Science.gov (United States)

    Yao, Fengchao; Hoteit, Ibrahim; Pratt, Larry J.; Bower, Amy S.; Köhl, Armin; Gopalakrishnan, Ganesh; Rivas, David

    2014-04-01

    The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented by 1980, and the climatological mean are analyzed using model output to delineate the three-dimensional structure and to investigate the underlying dynamical mechanisms. The horizontal model circulation in the winter of 1980 is dominated by energetic eddies. The climatological model mean results suggest that the surface inflow intensifies in a western boundary current in the southern Red Sea that switches to an eastern boundary current north of 24°N. The overturning is accomplished through a cyclonic recirculation and a cross-basin overturning circulation in the northern Red Sea, with major sinking occurring along a narrow band of width about 20 km along the eastern boundary and weaker upwelling along the western boundary. The northward pressure gradient force, strong vertical mixing, and horizontal mixing near the boundary are the essential dynamical components in the model's winter overturning circulation. The simulated water exchange is not hydraulically controlled in the Strait of Bab el Mandeb; instead, the exchange is limited by bottom and lateral boundary friction and, to a lesser extent, by interfacial friction due to the vertical viscosity at the interface between the inflow and the outflow.

  20. Late holocene primary productivity and sea surface temperature variations in the northeastern Arabian Sea: Implications for winter monsoon variability.

    Digital Repository Service at National Institute of Oceanography (India)

    Boll, A.; Luckge, A.; Munz, P.; Forke, S.; Schulz, H.; Ramaswamy, V.; Rixen, T.; Gaye, B.; Emeis, K.-C.

    changes in winter monsoon strength with winds from the northeast that drive convective mixing and high surface ocean productivity in the northeastern Arabian Sea. To establish a high-resolution record of winter monsoon variability for the late Holocene, we...

  1. Seasonal overturning circulation in the Red Sea: 2. Winter circulation

    KAUST Repository

    Yao, Fengchao

    2014-04-01

    The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented by 1980, and the climatological mean are analyzed using model output to delineate the three-dimensional structure and to investigate the underlying dynamical mechanisms. The horizontal model circulation in the winter of 1980 is dominated by energetic eddies. The climatological model mean results suggest that the surface inflow intensifies in a western boundary current in the southern Red Sea that switches to an eastern boundary current north of 24N. The overturning is accomplished through a cyclonic recirculation and a cross-basin overturning circulation in the northern Red Sea, with major sinking occurring along a narrow band of width about 20 km along the eastern boundary and weaker upwelling along the western boundary. The northward pressure gradient force, strong vertical mixing, and horizontal mixing near the boundary are the essential dynamical components in the model\\'s winter overturning circulation. The simulated water exchange is not hydraulically controlled in the Strait of Bab el Mandeb; instead, the exchange is limited by bottom and lateral boundary friction and, to a lesser extent, by interfacial friction due to the vertical viscosity at the interface between the inflow and the outflow. Key Points Sinking occurs in a narrow boundary layer along the eastern boundary Surface western boundary current switches into an eastern boundary current Water exchange in the Strait of Bab el Mandeb is not hydraulically controlled © 2014. American Geophysical Union. All Rights Reserved.

  2. Early Winter Sea Ice Dynamics in the Ross Sea from In Situ and Satellite Observations

    Science.gov (United States)

    Maksym, T.; Ackley, S. F.; Stammerjohn, S. E.; Tison, J. L.; Hoeppner, K.

    2017-12-01

    The Ross Sea sea ice cover is one of the few regions of the cryosphere that have been expanding in recent decades. However, 2017 saw a significantly delayed autumn ice advance and record low early winter sea ice extent. Understanding the causes and impacts of this variability has been hampered by a lack of in situ observations. A winter cruise into the Ross Sea in April-June 2017 provided some of the only in situ winter observations of sea ice processes in this region in almost 20 years. We present a first look at data from arrays of drifting buoys deployed in the ice pack and outflow from these polynyas, supplemented by a suite of high-resolution synthetic aperture radar (SAR) data. Additional observations included high-resolution sonar imagery of ice deformation features from an autonomous underwater vehicle, shipboard visual observations of sea ice properties, and in situ measurements of snow and thickness and structural properties. These data show that the delay in ice advance led to a thin, highly dynamic sea ice pack, with substantial ice production and export from the Ross Ice Shelf and Terra Nova Bay polynyas. Despite these high rates of ice production, the pack ice remained thin due to rapid export and northward drift. Compared to the only prior winter observations made in 1995 and 1998, the ice was thinner, with less ridging and snow cover, reflecting a younger ice cover. Granular ice was less prevalent than in these prior cruises, particularly in the outer pack, likely due to less snow ice formation and less pancake ice formation at the advancing ice edge. Despite rapid basal ice growth, the buoy data suggest that deformation may be the dominant mechanism for sea ice thickening in the pack once an initial ice cover forms.

  3. Year-to-year correlations in blood metal levels among individuals of two species of North American sea ducks

    International Nuclear Information System (INIS)

    Wayland, M.; Alisauskas, R.T.; Kellett, D.; Traylor, J.; Swoboda, C.; Neugebauer, E.; Mehl, K.

    2007-01-01

    Sea duck populations have declined in North America. Contaminants, especially metals, have been listed as possible contributing factors. Sea ducks are long-lived. Thus, individuals chronically exposed to elevated metal levels may be at greatest risk. Information about long-term exposure (≥1 year) of individuals to metals is absent. To address this information gap, we examined year-to-year correlations among individual White-Winged Scoters and King Eiders in levels of blood cadmium, lead, mercury and selenium. Positive correlations (r ≥ 0.43), were found in six, five, five and two of seven correlations for cadmium, selenium, lead and mercury. Thus, certain individuals of these species may be exposed over two or more years to higher levels of cadmium, selenium and lead (but apparently not mercury) than other individuals. Single blood samples are appropriate metrics of exposure for studies that examine long-term effects of certain metals on these birds. - Some individuals of two species of sea ducks experience greater long-term (≥1 year) exposure to cadmium, selenium and lead compared to other individuals

  4. Habitat use and foraging patterns of molting male Long-tailed Ducks in lagoons of the central Beaufort Sea, Alaska

    Science.gov (United States)

    Flint, Paul L.; Reed, John; Deborah Lacroix,; Richard Lanctot,

    2016-01-01

    From mid-July through September, 10 000 to 30 000 Long-tailed Ducks (Clangula hyemalis) use the lagoon systems of the central Beaufort Sea for remigial molt. Little is known about their foraging behavior and patterns of habitat use during this flightless period. We used radio transmitters to track male Long-tailed Ducks through the molt period from 2000 to 2002 in three lagoons: one adjacent to industrial oil field development and activity and two in areas without industrial activity. We found that an index to time spent foraging generally increased through the molt period. Foraging, habitat use, and home range size showed similar patterns, but those patterns were highly variable among lagoons and across years. Even with continuous daylight during the study period, birds tended to use offshore areas during the day for feeding and roosted in protected nearshore waters at night. We suspect that variability in behaviors associated with foraging, habitat use, and home range size are likely influenced by availability of invertebrate prey. Proximity to oil field activity did not appear to affect foraging behaviors of molting Long-tailed Ducks.

  5. Atmospheric Forcing of the Winter Air–Sea Heat Fluxes over the Northern Red Sea

    KAUST Repository

    Papadopoulos, Vassilis P.; Abualnaja, Yasser; Josey, Simon A.; Bower, Amy; Raitsos, Dionysios E.; Kontoyiannis, Harilaos; Hoteit, Ibrahim

    2013-01-01

    The influence of the atmospheric circulation on the winter air–sea heat fluxes over the northern Red Sea is investigated during the period 1985–2011. The analysis based on daily heat flux values reveals that most of the net surface heat exchange variability depends on the behavior of the turbulent components of the surface flux (the sum of the latent and sensible heat). The large-scale composite sea level pressure (SLP) maps corresponding to turbulent flux minima and maxima show distinct atmospheric circulation patterns associated with each case. In general, extreme heat loss (with turbulent flux lower than −400 W m−2) over the northern Red Sea is observed when anticyclonic conditions prevail over an area extending from the Mediterranean Sea to eastern Asia along with a recession of the equatorial African lows system. Subcenters of high pressure associated with this pattern generate the required steep SLP gradient that enhances the wind magnitude and transfers cold and dry air masses from higher latitudes. Conversely, turbulent flux maxima (heat loss minimization with values from −100 to −50 W m−2) are associated with prevailing low pressures over the eastern Mediterranean and an extended equatorial African low that reaches the southern part of the Red Sea. In this case, a smooth SLP field over the northern Red Sea results in weak winds over the area that in turn reduce the surface heat loss. At the same time, southerlies blowing along the main axis of the Red Sea transfer warm and humid air northward, favoring heat flux maxima.

  6. Atmospheric Forcing of the Winter Air–Sea Heat Fluxes over the Northern Red Sea

    KAUST Repository

    Papadopoulos, Vassilis P.

    2013-03-01

    The influence of the atmospheric circulation on the winter air–sea heat fluxes over the northern Red Sea is investigated during the period 1985–2011. The analysis based on daily heat flux values reveals that most of the net surface heat exchange variability depends on the behavior of the turbulent components of the surface flux (the sum of the latent and sensible heat). The large-scale composite sea level pressure (SLP) maps corresponding to turbulent flux minima and maxima show distinct atmospheric circulation patterns associated with each case. In general, extreme heat loss (with turbulent flux lower than −400 W m−2) over the northern Red Sea is observed when anticyclonic conditions prevail over an area extending from the Mediterranean Sea to eastern Asia along with a recession of the equatorial African lows system. Subcenters of high pressure associated with this pattern generate the required steep SLP gradient that enhances the wind magnitude and transfers cold and dry air masses from higher latitudes. Conversely, turbulent flux maxima (heat loss minimization with values from −100 to −50 W m−2) are associated with prevailing low pressures over the eastern Mediterranean and an extended equatorial African low that reaches the southern part of the Red Sea. In this case, a smooth SLP field over the northern Red Sea results in weak winds over the area that in turn reduce the surface heat loss. At the same time, southerlies blowing along the main axis of the Red Sea transfer warm and humid air northward, favoring heat flux maxima.

  7. Vertical distribution of mesozooplankton in the central and eastern Arabian Sea during the winter monsoons

    Digital Repository Service at National Institute of Oceanography (India)

    Padmavati, G.; Haridas, P.; Nair, K.K.C.; Gopalakrishnan, T.C.; Shiney, P.; Madhupratap, M.

    The vertical distribution of mesozooplankton in the central and eastern Arabian Sea was investigated during the winter monsoon in 1995. Samples were analysed from discrete depth zones defined according to oxygen and temperature profiles of the water...

  8. Winter Arctic sea ice growth: current variability and projections for the coming decades

    Science.gov (United States)

    Petty, A.; Boisvert, L.; Webster, M.; Holland, M. M.; Bailey, D. A.; Kurtz, N. T.; Markus, T.

    2017-12-01

    Arctic sea ice increases in both extent and thickness during the cold winter months ( October to May). Winter sea ice growth is an important factor controlling ocean ventilation and winter water/deep water formation, as well as determining the state and vulnerability of the sea ice pack before the melt season begins. Key questions for the Arctic community thus include: (i) what is the current magnitude and variability of winter Arctic sea ice growth and (ii) how might this change in a warming Arctic climate? To address (i), our current best guess of pan-Arctic sea ice thickness, and thus volume, comes from satellite altimetry observations, e.g. from ESA's CryoSat-2 satellite. A significant source of uncertainty in these data come from poor knowledge of the overlying snow depth. Here we present new estimates of winter sea ice thickness from CryoSat-2 using snow depths from a simple snow model forced by reanalyses and satellite-derived ice drift estimates, combined with snow depth estimates from NASA's Operation IceBridge. To address (ii), we use data from the Community Earth System Model's Large Ensemble Project, to explore sea ice volume and growth variability, and how this variability might change over the coming decades. We compare and contrast the model simulations to observations and the PIOMAS ice-ocean model (over recent years/decades). The combination of model and observational analysis provide novel insight into Arctic sea ice volume variability.

  9. Definition of water exchange zone between the Bohai Sea and Yellow Sea and the effect of winter gale on it

    Institute of Scientific and Technical Information of China (English)

    SONG Jun; GUO Junru; LI Jing; MU Lin; LIU Yulong; WANG Guosong; LI Yan; LI Huan

    2017-01-01

    The marine dynamic environment of the Bohai Sea and the Yellow Sea in the winter of 2006 is simulated by the Regional Ocean Modelling System (ROMS) marine numerical model. Using the simulated temperature and salinity, the water exchange zone between the Bohai Sea and Yellow Sea is defined through the Spectral Mixture Model (SMM). The influence of winter gales on the water exchange is also discussed. It is found that the Yellow Sea water masses in winter are distributed in a “tongue” shape in the Bohai Strait region, the water exchange zone presents a zonal distribution along the margin of the “tongue”, with a tendency of running from northwest to southeast, and the water exchange is intensified at the tip of the “tongue”. Besides, the coastal area in the northernmost Yellow Sea does not participate in the water exchange between the Bohai Sea and Yellow Sea. The result shows that the winter gale events play a role in enhancing the water exchange. It is specifically shown by the facts: the Yellow Sea warm current is enhanced to intrude the Bohai Sea by the gale process; the water exchange zone extends into the Bohai Sea; the water exchange belt in the southern part becomes wider; the mixture zone of river runoff with the Bohai Sea water upon its entry is enlarged and shifts northwards. Within two days after the gale process, the exchange zone retreats toward the Yellow Sea and the exchange zone resulted from the Huanghe River (Yellow River) runoff also shrinks back shoreward.

  10. On the potential for abrupt Arctic winter sea-ice loss

    NARCIS (Netherlands)

    Bathiany, S.; Notz, Dirk; Mauritsen, T.; Raedel, G.; Brovkin, V.

    2016-01-01

    The authors examine the transition from a seasonally ice-covered Arctic to an Arctic Ocean that is sea ice free all year round under increasing atmospheric CO2 levels. It is shown that in comprehensive climate models, such loss of Arctic winter sea ice area is faster than the preceding loss of

  11. Radiation preservation of sea-foods : development of dehydro-irradiation processes for shrimp (Penaeus indicus) and Bombay duck (Harpodon nehereus)

    International Nuclear Information System (INIS)

    Lewis, N.F.

    1978-01-01

    Bombay duck which comprises more than 10% of India's annual fish catch is not amenable to freezing and canning mainly due to the high content of free water and extreme lability of its proteins. The commercially available sun-dried product is suspect to rapid spoilage by mould leading to impairment of organoleptic qualities. The dehydro-irradiation process using heat and gamma radiation has been developed to stabilise sea foods and is studied with Bombay duck (Harpodon nehereus) and shrimp (Penaeus indicus). The process has been found to preserve Bombay duck laminates for a period of four months at ambient temperature and the products are more superior in organoleptic qualities to those prepared by the conventional sun-drying method. (M.G.B.)

  12. Linking Regional Winter Sea Ice Thickness and Surface Roughness to Spring Melt Pond Fraction on Landfast Arctic Sea Ice

    Directory of Open Access Journals (Sweden)

    Sasha Nasonova

    2017-12-01

    Full Text Available The Arctic sea ice cover has decreased strongly in extent, thickness, volume and age in recent decades. The melt season presents a significant challenge for sea ice forecasting due to uncertainty associated with the role of surface melt ponds in ice decay at regional scales. This study quantifies the relationships of spring melt pond fraction (fp with both winter sea ice roughness and thickness, for landfast first-year sea ice (FYI and multiyear sea ice (MYI. In 2015, airborne measurements of winter sea ice thickness and roughness, as well as high-resolution optical data of melt pond covered sea ice, were collected along two ~5.2 km long profiles over FYI- and MYI-dominated regions in the Canadian Arctic. Statistics of winter sea ice thickness and roughness were compared to spring fp using three data aggregation approaches, termed object and hybrid-object (based on image segments, and regularly spaced grid-cells. The hybrid-based aggregation approach showed strongest associations because it considers the morphology of the ice as well as footprints of the sensors used to measure winter sea ice thickness and roughness. Using the hybrid-based data aggregation approach it was found that winter sea ice thickness and roughness are related to spring fp. A stronger negative correlation was observed between FYI thickness and fp (Spearman rs = −0.85 compared to FYI roughness and fp (rs = −0.52. The association between MYI thickness and fp was also negative (rs = −0.56, whereas there was no association between MYI roughness and fp. 47% of spring fp variation for FYI and MYI can be explained by mean thickness. Thin sea ice is characterized by low surface roughness allowing for widespread ponding in the spring (high fp whereas thick sea ice has undergone dynamic thickening and roughening with topographic features constraining melt water into deeper channels (low fp. This work provides an important contribution towards the parameterizations of fp in

  13. Picophytoplankton variability: Influence of winter convective mixing and advection in the northeastern Arabian Sea

    Science.gov (United States)

    Bemal, Suchandan; Anil, Arga Chandrashekar; Shankar, D.; Remya, R.; Roy, Rajdeep

    2018-04-01

    The deepening of mixed layer and ensuing changes in optical and physicochemical properties of euphotic zone can influence phytoplankton community dynamics in the northeastern Arabian Sea during winter monsoon. The response of picophytoplankton community to such changes during winter convective mixing is not well understood. Herein, we have compared variations in the picophytoplankton community structure during early (November-December 2012), peak (end-January 2014) and late (mid-February 2015) winter monsoon from three separate cruises in the southern northeastern Arabian Sea. The higher Synechococcus abundance owing to entrainment of nutrients in mixed layer was observed during peak winter monsoon, while the concomitant changes in nitrate concentration, light and oxygen environment restricted Prochlorococcus growth resulting in lower abundance during the same period. This highlights the diverse responses of picophytoplankton groups to physicochemical changes of water column during winter convective mixing. The divinyl chlorophyll b/a ratio (marker for Prochlorococcus ecotypes) indicated prevalence of one low-light adapted ecotype (sensitive to light shock) in sub-surface water, one high-light adapted ecotype in surface water during early winter monsoon and both disappeared during intense mixing period in peak winter monsoon. Subsequently, a distinct low-light adapted ecotype, capable to tolerate light shock, was noticed during late winter monsoon and we argue that this ecotype is introduced to southern northeastern Arabian Sea through advection from north by sub-surface circulation. The total picophytoplankton biomass available to microbial loop is restored during late winter monsoon, when stratification begins, with a higher abundance of Synechococcus and the re-occurrence of Prochlorococcus population in the region. These inferences indicate that variability in picophytoplankton community structure and their contribution to the microbial loop are driven by

  14. Dynamic and thermodynamic impacts of the winter Arctic Oscillation on summer sea ice extent.

    Science.gov (United States)

    Park, H. S.; Stewart, A.

    2017-12-01

    Arctic summer sea ice extent exhibits substantial interannual variability, as is highlighted by the remarkable recovery in sea ice extent in 2013 following the record minimum in the summer of 2012. Here, we explore the mechanism via which Arctic Oscillation (AO)-induced ice thickness changes impact summer sea ice, using observations and reanalysis data. A positive AO weakens the basin-scale anticyclonic sea ice drift and decreases the winter ice thickness by 15cm and 10cm in the Eurasian and the Pacific sectors of the Arctic respectively. Three reanalysis datasets show that the (upward) surface heat fluxes are reduced over wide areas of the Arctic, suppressing the ice growth during the positive AO winters. The winter dynamic and thermodynamic thinning preconditions the ice for enhanced radiative forcing via the ice-albedo feedback in late spring-summer, leading to an additional 8-10 cm of thinning over the Pacific sector of the Arctic. Because of these winter AO-induced dynamic and thermodynamics effects, the winter AO explains about 22% (r = -0.48) of the interannual variance of September sea ice extent from year 1980 to 2015.

  15. A Possible Link Between Winter Arctic Sea Ice Decline and a Collapse of the Beaufort High?

    Science.gov (United States)

    Petty, Alek A.

    2018-03-01

    A new study by Moore et al. (2018, https://doi.org/10.1002/2017GL076446) highlights a collapse of the anticyclonic "Beaufort High" atmospheric circulation over the western Arctic Ocean in the winter of 2017 and an associated reversal of the sea ice drift through the southern Beaufort Sea (eastward instead of the predominantly westward circulation). The authors linked this to the loss of sea ice in the Barents Sea, anomalous warming over the region, and the intrusion of low-pressure cyclones along the eastern Arctic. In this commentary we discuss the significance of this observation, the challenges associated with understanding these possible linkages, and some of the alternative hypotheses surrounding the impacts of winter Arctic sea ice loss.

  16. A numerical study of the South China Sea Warm Current during winter monsoon relaxation

    Science.gov (United States)

    Zhang, Cong; Ding, Yang; Bao, Xianwen; Bi, Congcong; Li, Ruixiang; Zhang, Cunjie; Shen, Biao; Wan, Kai

    2018-03-01

    Using a Finite-Volume Community Ocean Model, we investigated the dynamic mechanism of the South China Sea Warm Current (SCSWC) in the northern South China Sea (NSCS) during winter monsoon relaxation. The model reproduces the mean surface circulation of the NSCS during winter, while model-simulated subtidal currents generally capture its current pattern. The model shows that the current over the continental shelf is generally southwestward, under a strong winter monsoon condition, but a northeastward counter-wind current usually develops between 50-and 100-m isobaths, when the monsoon relaxes. Model experiments, focusing on the wind relaxation process, show that sea level is elevated in the northwestern South China Sea (SCS), related to the persistent northeasterly monsoon. Following wind relaxation, a high sea level band builds up along the mid-shelf, and a northeastward current develops, having an obvious vertical barotropic structure. Momentum balance analysis indicates that an along-shelf pressure gradient provides the initial driving force for the SCSWC during the first few days following wind relaxation. The SCSWC subsequently reaches a steady quasi-geostrophic balance in the cross-shelf direction, mainly linked to sea level adjustment over the shelf. Lagrangian particle tracking experiments show that both the southwestward coastal current and slope current contribute to the northeastward movement of the SCSWC during winter monsoon relaxation.

  17. Influence of winter sea-ice motion on summer ice cover in the Arctic

    Directory of Open Access Journals (Sweden)

    Noriaki Kimura

    2013-11-01

    Full Text Available Summer sea-ice cover in the Arctic varies largely from year to year owing to several factors. This study examines one such factor, the relationship between interannual difference in winter ice motion and ice area in the following summer. A daily-ice velocity product on a 37.5-km resolution grid is prepared using the satellite passive microwave sensor Advanced Microwave Scanning Radiometer—Earth Observing System data for the nine years of 2003–2011. Derived daily-ice motion reveals the dynamic modification of the winter ice cover. The winter ice divergence/convergence is strongly related to the summer ice cover in some regions; the correlation coefficient between the winter ice convergence and summer ice area ranges between 0.5 and 0.9 in areas with high interannual variability. This relation implies that the winter ice redistribution controls the spring ice thickness and the summer ice cover.

  18. Effect of Sea Tangle ( and Charcoal Supplementation as Alternatives to Antibiotics on Growth Performance and Meat Quality of Ducks

    Directory of Open Access Journals (Sweden)

    M. M. Islam

    2014-02-01

    Full Text Available A total of 150 growing ducks were assigned to five dietary treatments to study the effect of sea tangle and charcoal (STC supplementation on growth performance and meat characteristics in a completely randomized design. There were six replicates and five ducklings in each replication. The five dietary treatments were control, antibiotic, and 0.1%, 0.5%, and 1% STC supplemented diets. No significant differences were found on ADG, ADFI, and gain:feed among treatments in different weeks. The overall (0 to 3 weeks ADFI decreased in antibiotic treatment (p<0.05 whereas the gain:feed increased significantly upon 1.0% STC supplementation compared to control (p<0.05. No significant variation was found in meat chemical composition except crude fat content which was high in 1.0% STC dietary group (p<0.05. Meat cholesterol was reduced in 0.1% STC group (p<0.05 compared to other dose levels while serum cholesterol was unaffected. High density lipoprotein (HDL content was high in 1.0% STC (p<0.05 and low density lipoprotein (LDL was low in 0.1% and 1.0% STC dietary groups (p = 0.06. No significant effect was found on the thiobarbituric acid reactive substances (TBARS of fresh meat, whereas the TBARS value of meat preserved for 1 week was reduced significantly in STC dietary groups (p<0.05. The 0.1% STC dietary group showed an increased myristic acid (p = 0.07 content whereas, the content of eicosapentaenoic (EPA and docosahexaenoic (DHA acids increased in STC supplementation than antibiotic group (p<0.05. An increased concentration of omega-3 fatty acids and a reduced ratio of n-6/n-3 PUFA ratio was found upon 1.0% STC supplementation compared to antibiotic dietary group (p<0.05. Therefore, 1.0% STC dietary supplementation can be used as alternatives to antibiotics in duck production.

  19. Collapse of the 2017 Winter Beaufort High: A Response to Thinning Sea Ice?

    Science.gov (United States)

    Moore, G. W. K.; Schweiger, A.; Zhang, J.; Steele, M.

    2018-03-01

    The winter Arctic atmosphere is under the influence of two very different circulation systems: extratropical cyclones travel along the primary North Atlantic storm track from Iceland toward the eastern Arctic, while the western Arctic is characterized by a quasi-stationary region of high pressure known as the Beaufort High. The winter (January through March) of 2017 featured an anomalous reversal of the normally anticyclonic surface winds and sea ice motion in the western Arctic. This reversal can be traced to a collapse of the Beaufort High as the result of the intrusion of low-pressure systems from the North Atlantic, along the East Siberian Coast, into the Arctic Basin. Thin sea ice as the result of an extremely warm autumn (October through December) of 2016 contributed to the formation of an anomalous thermal low over the Barents Sea that, along with a northward shift of the tropospheric polar vortex, permitted this intrusion. The collapse of the Beaufort High during the winter of 2017 was associated with simultaneous 2-sigma sea level pressure, surface wind, and sea ice circulation anomalies in the western Arctic. As the Arctic sea ice continues to thin, such reversals may become more common and impact ocean circulation, sea ice, and biology.

  20. Air-sea interactions during strong winter extratropical storms

    Science.gov (United States)

    Nelson, Jill; He, Ruoying; Warner, John C.; Bane, John

    2014-01-01

    A high-resolution, regional coupled atmosphere–ocean model is used to investigate strong air–sea interactions during a rapidly developing extratropical cyclone (ETC) off the east coast of the USA. In this two-way coupled system, surface momentum and heat fluxes derived from the Weather Research and Forecasting model and sea surface temperature (SST) from the Regional Ocean Modeling System are exchanged via the Model Coupling Toolkit. Comparisons are made between the modeled and observed wind velocity, sea level pressure, 10 m air temperature, and sea surface temperature time series, as well as a comparison between the model and one glider transect. Vertical profiles of modeled air temperature and winds in the marine atmospheric boundary layer and temperature variations in the upper ocean during a 3-day storm period are examined at various cross-shelf transects along the eastern seaboard. It is found that the air–sea interactions near the Gulf Stream are important for generating and sustaining the ETC. In particular, locally enhanced winds over a warm sea (relative to the land temperature) induce large surface heat fluxes which cool the upper ocean by up to 2 °C, mainly during the cold air outbreak period after the storm passage. Detailed heat budget analyses show the ocean-to-atmosphere heat flux dominates the upper ocean heat content variations. Results clearly show that dynamic air–sea interactions affecting momentum and buoyancy flux exchanges in ETCs need to be resolved accurately in a coupled atmosphere–ocean modeling framework.

  1. Science foundation Chapter 5 Appendix 5.1: Case study diving ducks

    Science.gov (United States)

    Takekawa, John Y.; De La Cruz, Susan; Ackerman, Joshua T.; Yarris, Gregory S.

    2015-01-01

    Diving ducks are the most abundant group of waterfowl that overwinter in the open bays and ponds of San Francisco Bay (SFB). Species within this group are primarily benthivores that dive to obtain their macroinvertebrate prey in bottom sediments, although at times they may eat plant matter or forage in the water column. These migratory species include bay ducks (lesser scaup Aythya affinis, greater scaup A. marila, canvasback A. valisineria), sea ducks (surf scoter Melanitta perspicillata and bufflehead Bucephala albeola), and a stiff-tailed duck (ruddy duck Oxyura jamaicensis). These species vary from largest to smallest body mass: canvasback, greater scaup, surf scoter, lesser scaup, ruddy duck, and bufflehead. Their breeding grounds range from Central Valley grasslands, intermountain wetlands, prairie potholes, boreal forest, and Arctic tundra. Their wintering populations in SFB are most abundant between October and April, and SFB comprises up to 50% of the number counted during midwinter surveys on the lower Pacific coast. Species are found in all SFB regions, but greater scaup and surf scoter are most often seen in subtidal to intertidal waters and are not commonly found in baylands. In contrast, ruddy duck and bufflehead populations are most abundant in baylands, particularly in managed ponds. Canvasbacks are commonly found at estuaries or creek mouths.

  2. Wintering Tufted Ducks Aythya fuligula diving for zebra mussels Dreissena polymorpha balance feeding costs within narrow margins of their energy budget

    NARCIS (Netherlands)

    Leeuw, de J.J.; Eerden, van M.R.; Visser, G.H.

    1999-01-01

    Diving ducks face the strongly cooling properties of aquatic environments. In experiments with Tufted Ducks Aythya fuligula feeding on zebra mussels Dreissena polymorpha in outdoor cages, we measured changes in food consumption and diving behaviour in relation to water temperature (3-22°C). Water

  3. Wintering Tufted Ducks Aythya fuligula diving for zebra mussels Dreissena polymorpha balance feeding costs within narrow margins of their energy budget

    NARCIS (Netherlands)

    de Leeuw, JJ; van Eerden, MR; Visser, GH

    Diving ducks face the strongly cooling properties of aquatic environments. In experiments with Tufted Ducks Aythya fuligula feeding on zebra mussels Dreissena polymorpha in outdoor cages, we measured changes in food consumption and diving behaviour in relation to water temperature (3-22 degrees C).

  4. The Formation each Winter of the Circumpolar Wave in the Sea Ice around Antarctica

    Science.gov (United States)

    Gloersen, Per; White, Warren B.

    1999-01-01

    Seeking to improve upon the visualization of the Antarctic Circumpolar Wave (ACW) , we compare a 16-year sequence of 6-month winter averages of Antarctic sea ice extents and concentrations with those of adjacent sea surface temperatures (SSTs). Here we follow SSTs around the globe along the maximum sea ice edge rather than in a zonal band equatorward of it. The results are similar to the earlier ones, but the ACWs do not propagate with equal amplitude or speed. Additionally in a sequence of 4 polar stereographic plots of these SSTs and sea ice concentrations, we find a remarkable correlation between SST minima and sea ice concentration maxima, even to the extent of matching contours across the ice-sea boundary, in the sector between 900E and the Palmer Peninsula. Based on these observations, we suggest that the memory of the ACW in the sea ice is carried from one Austral winter to the next by the neighboring SSTS, since the sea ice is nearly absent in the Austral summer.

  5. Dynamics of sea-ice biogeochemistry in the coastal Antarctica during transition from summer to winter

    Directory of Open Access Journals (Sweden)

    Suhas Shetye

    2017-05-01

    Full Text Available The seasonality of carbon dioxide partial pressure (pCO2, air-sea CO2 fluxes and associated environmental parameters were investigated in the Antarctic coastal waters. The in-situ survey was carried out from the austral summer till the onset of winter (January 2012, February 2010 and March 2009 in the Enderby Basin. Rapid decrease in pCO2 was evident under the sea-ice cover in January, when both water column and sea-ice algal activity resulted in the removal of nutrients and dissolved inorganic carbon (DIC and increase in pH. The major highlight of this study is the shift in the dominant biogeochemical factors from summer to early winter. Nutrient limitation (low Si/N, sea-ice cover, low photosynthetically active radiation (PAR, deep mixed layer and high upwelling velocity contributed towards higher pCO2 during March (early winter. CO2 fluxes suggest that the Enderby Basin acts as a strong CO2 sink during January (−81 mmol m−2 d−1, however it acts as a weak sink of CO2 with −2.4 and −1.7 mmol m−2 d−1 during February and March, respectively. The present work, concludes that sea ice plays a dual role towards climate change, by decreasing sea surface pCO2 in summer and enhancing in early winter. Our observations emphasize the need to address seasonal sea-ice driven CO2 flux dynamics in assessing Antarctic contributions to the global oceanic CO2 budget.

  6. Abnormal Winter Melting of the Arctic Sea Ice Cap Observed by the Spaceborne Passive Microwave Sensors

    Directory of Open Access Journals (Sweden)

    Seongsuk Lee

    2016-12-01

    Full Text Available The spatial size and variation of Arctic sea ice play an important role in Earth’s climate system. These are affected by conditions in the polar atmosphere and Arctic sea temperatures. The Arctic sea ice concentration is calculated from brightness temperature data derived from the Defense Meteorological Satellite program (DMSP F13 Special Sensor Microwave/Imagers (SSMI and the DMSP F17 Special Sensor Microwave Imager/Sounder (SSMIS sensors. Many previous studies point to significant reductions in sea ice and their causes. We investigated the variability of Arctic sea ice using the daily and monthly sea ice concentration data from passive microwave observations to identify the sea ice melting regions near the Arctic polar ice cap. We discovered the abnormal melting of the Arctic sea ice near the North Pole even during the summer and the winter. This phenomenon is hard to explain only surface air temperature or solar heating as suggested by recent studies. We propose a hypothesis explaining this phenomenon. The heat from the deep sea in Arctic Ocean ridges and/or the hydrothermal vents might be contributing to the melting of Arctic sea ice. This hypothesis could be verified by the observation of warm water column structure below the melting or thinning arctic sea ice through the project such as Coriolis dataset for reanalysis (CORA.

  7. Large scale features and energetics of the hybrid subtropical low `Duck' over the Tasman Sea

    Science.gov (United States)

    Pezza, Alexandre Bernardes; Garde, Luke Andrew; Veiga, José Augusto Paixão; Simmonds, Ian

    2014-01-01

    New aspects of the genesis and partial tropical transition of a rare hybrid subtropical cyclone on the eastern Australian coast are presented. The `Duck' (March 2001) attracted more recent attention due to its underlying genesis mechanisms being remarkably similar to the first South Atlantic hurricane (March 2004). Here we put this cyclone in climate perspective, showing that it belongs to a class within the 1 % lowest frequency percentile in the Southern Hemisphere as a function of its thermal evolution. A large scale analysis reveals a combined influence from an existing tropical cyclone and a persistent mid-latitude block. A Lagrangian tracer showed that the upper level air parcels arriving at the cyclone's center had been modified by the blocking. Lorenz energetics is used to identify connections with both tropical and extratropical processes, and reveal how these create the large scale environment conducive to the development of the vortex. The results reveal that the blocking exerted the most important influence, with a strong peak in barotropic generation of kinetic energy over a large area traversed by the air parcels just before genesis. A secondary peak also coincided with the first time the cyclone developed an upper level warm core, but with insufficient amplitude to allow for a full tropical transition. The applications of this technique are numerous and promising, particularly on the use of global climate models to infer changes in environmental parameters associated with severe storms.

  8. Sensitivity of the sea ice concentration over the Kara-Barents Sea in autumn to the winter temperature variability over East Asia

    Science.gov (United States)

    Cho, K. H.; Chang, E. C.

    2017-12-01

    In this study, we performed sensitivity experiments by utilizing the Global/Regional Integrated Model system with different conditions of the sea ice concentration over the Kara-Barents (KB) Sea in autumn, which can affect winter temperature variability over East Asia. Prescribed sea ice conditions are 1) climatological autumn sea ice concentration obtained from 1982 to 2016, 2) reduced autumn sea ice concentration by 50% of the climatology, and 3) increased autumn sea ice concentration by 50% of climatology. Differently prescribed sea ice concentration changes surface albedo, which affects surface heat fluxes and near-surface air temperature. The reduced (increased) sea ice concentration over the KB sea increases (decreases) near-surface air temperature that leads the lower (higher) sea level pressure in autumn. These patterns are maintained from autumn to winter season. Furthermore, it is shown that the different sea ice concentration over the KB sea has remote effects on the sea level pressure patterns over the East Asian region. The lower (higher) sea level pressure over the KB sea by the locally decreased (increased) ice concentration is related to the higher (lower) pressure pattern over the Siberian region, which induces strengthened (weakened) cold advection over the East Asian region. From these sensitivity experiments it is clarified that the decreased (increased) sea ice concentration over the KB sea in autumn can lead the colder (warmer) surface air temperature over East Asia in winter.

  9. Biogeochemical Impact of Snow Cover and Cyclonic Intrusions on the Winter Weddell Sea Ice Pack

    Science.gov (United States)

    Tison, J.-L.; Schwegmann, S.; Dieckmann, G.; Rintala, J.-M.; Meyer, H.; Moreau, S.; Vancoppenolle, M.; Nomura, D.; Engberg, S.; Blomster, L. J.; Hendrickx, S.; Uhlig, C.; Luhtanen, A.-M.; de Jong, J.; Janssens, J.; Carnat, G.; Zhou, J.; Delille, B.

    2017-12-01

    Sea ice is a dynamic biogeochemical reactor and a double interface actively interacting with both the atmosphere and the ocean. However, proper understanding of its annual impact on exchanges, and therefore potentially on the climate, notably suffer from the paucity of autumnal and winter data sets. Here we present the results of physical and biogeochemical investigations on winter Antarctic pack ice in the Weddell Sea (R. V. Polarstern AWECS cruise, June-August 2013) which are compared with those from two similar studies conducted in the area in 1986 and 1992. The winter 2013 was characterized by a warm sea ice cover due to the combined effects of deep snow and frequent warm cyclones events penetrating southward from the open Southern Ocean. These conditions were favorable to high ice permeability and cyclic events of brine movements within the sea ice cover (brine tubes), favoring relatively high chlorophyll-a (Chl-a) concentrations. We discuss the timing of this algal activity showing that arguments can be presented in favor of continued activity during the winter due to the specific physical conditions. Large-scale sea ice model simulations also suggest a context of increasingly deep snow, warm ice, and large brine fractions across the three observational years, despite the fact that the model is forced with a snowfall climatology. This lends support to the claim that more severe Antarctic sea ice conditions, characterized by a longer ice season, thicker, and more concentrated ice are sufficient to increase the snow depth and, somehow counterintuitively, to warm the ice.

  10. Long-term monitoring program: Evaluating chronic exposure of harlequin ducks and sea otters to lingering Exxon Valdez Oil in Western Prince William Sound

    Science.gov (United States)

    Esler, Daniel N.; Bowen, Lizabeth; Miles, A. Keith; Ballachey, Brenda E.; Bodkin, James L.

    2015-01-01

    We found that average cytochrome P4501A induction (as measured by EROD activity) during March 2014 was not elevated in wintering harlequin ducks captured in areas of Prince William Sound oiled by the 1989 Exxon Valdez oil spill, relative to those captured in unoiled areas. This result is consistent with findings from March 2013. We interpret these findings to indicate that exposure of harlequin ducks to residual Exxon Valdez oil abated within 24 years after the original spill. Results from preceding sampling in 2011 indicated that EROD activity was elevated in harlequin ducks in oiled relative to unoiled areas, although the magnitude of elevation was lower than in previous years (1998-2009), suggesting that the rate or intensity of exposure was diminishing by 2011. The data presented in this report add to a growing body of literature indicating that persistence of oil in the environment, and exposure of wildlife to that oil, can occur over much longer time frames than previously assumed.

  11. NUTRITION AS POSSIBLE ETHIOLOGICAL AGENT OF WINTER DISEASE SYNDROME IN SEA BREAM (Sparus aurata L.

    Directory of Open Access Journals (Sweden)

    Gordana Šarušić

    2000-12-01

    Full Text Available The circumstance of winter disease phenomenon in intensively reared sea bream (Sparus aurata L. has been described. It’s occurence in Mediterranean has been registered and reported by several authors. The aim of this paper is to contribute to the comprehension on the aethiology of this syndrome which is causing significant losses in one year old cultured fish. Different types of commercial diets were introduced during 1994/95 rearing season to the sea bream reared in floating cages. The feeds were displaying differences in energetic compound level and vitamin A, D3 and E content. Health difficulties and mortality in the observed fish groups at the beginning of the problem, did not indicate any biotic agent as being responsible for such condition. Clinical features and mortality in the groups affected by winter disease syndrome were increasing by low sea temperature and correlating with feeding period by food containing low levels of protein, lipids and vitamins. Pathological findings were in particularly related to the organs involved in digestion. Growth rate was characteristic for the group that were suffering winter disease, where increasing in length was not followed by body weight. Clinical signs, simptomathology related to the organs involved in digestion, liver histology analyses, weight losses and pattern of weight and length relation, correlation between used feeds and occurrence of winter disease, implicated nutrition as one of most possible ethiological agent of this condition. Nutritional interventions applied contributed in comprehension of the winter disease syndrome. The relationship between nutritional requirements, particularly regerding autumn-winter period, has been researched and analyzed. The results approved our basic hypothesis.

  12. Arctic sea ice, Eurasia snow, and extreme winter haze in China.

    Science.gov (United States)

    Zou, Yufei; Wang, Yuhang; Zhang, Yuzhong; Koo, Ja-Ho

    2017-03-01

    The East China Plains (ECP) region experienced the worst haze pollution on record for January in 2013. We show that the unprecedented haze event is due to the extremely poor ventilation conditions, which had not been seen in the preceding three decades. Statistical analysis suggests that the extremely poor ventilation conditions are linked to Arctic sea ice loss in the preceding autumn and extensive boreal snowfall in the earlier winter. We identify the regional circulation mode that leads to extremely poor ventilation over the ECP region. Climate model simulations indicate that boreal cryospheric forcing enhances the regional circulation mode of poor ventilation in the ECP region and provides conducive conditions for extreme haze such as that of 2013. Consequently, extreme haze events in winter will likely occur at a higher frequency in China as a result of the changing boreal cryosphere, posing difficult challenges for winter haze mitigation but providing a strong incentive for greenhouse gas emission reduction.

  13. Impact of sea ice cover changes on the Northern Hemisphere atmospheric winter circulation

    Directory of Open Access Journals (Sweden)

    D. Handorf

    2012-01-01

    Full Text Available The response of the Arctic atmosphere to low and high sea ice concentration phases based on European Center for Medium-Range Weather Forecast (ECMWF Re-Analysis Interim (ERA-Interim atmospheric data and Hadley Centre's sea ice dataset (HadISST1 from 1989 until 2010 has been studied. Time slices of winter atmospheric circulation with high (1990–2000 and low (2001–2010 sea ice concentration in the preceding August/September have been analysed with respect to tropospheric interactions between planetary and baroclinic waves. It is shown that a changed sea ice concentration over the Arctic Ocean impacts differently the development of synoptic and planetary atmospheric circulation systems. During the low ice phase, stronger heat release to the atmosphere over the Arctic Ocean reduces the atmospheric vertical static stability. This leads to an earlier onset of baroclinic instability that further modulates the non-linear interactions between baroclinic wave energy fluxes on time scales of 2.5–6 d and planetary scales of 10–90 d. Our analysis suggests that Arctic sea ice concentration changes exert a remote impact on the large-scale atmospheric circulation during winter, exhibiting a barotropic structure with similar patterns of pressure anomalies at the surface and in the mid-troposphere. These are connected to pronounced planetary wave train changes notably over the North Pacific.

  14. Long-term changes of South China Sea surface temperatures in winter and summer

    Science.gov (United States)

    Park, Young-Gyu; Choi, Ara

    2017-07-01

    Utilizing available atmospheric and oceanographic reanalysis data sets, the long-term trend in South China Sea (SCS) sea surface temperature (SST) between 1950 and 2008 and the governing processes are investigated. Both winter and summer SST increased by comparable amounts, but the warming patterns and the governing processes were different. Strong warming in winter occurred in a deep central area, and during summer in the southern region. In winter the net heat flux into the sea increased, contributing to the warming. The spatial pattern of the heat flux, however, was different from that of the warming. Heat flux increased over the coastal area where warming was weaker, but decreased over the deeper area where warming was stronger. The northeasterly monsoon wind weakened lowering the shoreward Ekman transport and the sea surface height gradient. The cyclonic gyre which transports cold northern water to the south weakened, thereby warming the ocean. The effect was manifested more strongly along the southward western boundary current inducing warming in the deep central part. In summer however, the net surface heat flux decreased and could not contribute to the warming. Over the southern part of the SCS, the weakening of the southwesterly summer monsoon reduced southeastward Ekman transport, which is parallel to the mean SST gradient. Southeastward cold advection due to Ekman transport was reduced, thereby warming the surface near the southeastern boundary of the SCS. Upwelling southeast of Vietnam was also weakened, raising the SST east of Vietnam contributing to the southern summer warming secondarily. The weakening of the winds in each season was the ultimate cause of the warming, but the responses of the ocean that lead to the warming were different in winter and summer.

  15. Remarkable link between projected uncertainties of Arctic sea-ice decline and winter Eurasian climate

    Science.gov (United States)

    Cheung, Hoffman H. N.; Keenlyside, Noel; Omrani, Nour-Eddine; Zhou, Wen

    2018-01-01

    We identify that the projected uncertainty of the pan-Arctic sea-ice concentration (SIC) is strongly coupled with the Eurasian circulation in the boreal winter (December-March; DJFM), based on a singular value decomposition (SVD) analysis of the forced response of 11 CMIP5 models. In the models showing a stronger sea-ice decline, the Polar cell becomes weaker and there is an anomalous increase in the sea level pressure (SLP) along 60°N, including the Urals-Siberia region and the Iceland low region. There is an accompanying weakening of both the midlatitude westerly winds and the Ferrell cell, where the SVD signals are also related to anomalous sea surface temperature warming in the midlatitude North Atlantic. In the Mediterranean region, the anomalous circulation response shows a decreasing SLP and increasing precipitation. The anomalous SLP responses over the Euro-Atlantic region project on to the negative North Atlantic Oscillation-like pattern. Altogether, pan-Arctic SIC decline could strongly impact the winter Eurasian climate, but we should be cautious about the causality of their linkage.

  16. Do common eiders nest in kin groups? Microgeographic genetic structure in a philopatric sea duck

    Science.gov (United States)

    Sonsthagen, S.A.; Talbot, S.L.; Lanctot, Richard B.; McCracken, K.G.

    2010-01-01

    We investigated local genetic associations among female Pacific common eiders (Somateria mollissima v-nigrum) nesting in a stochastic Arctic environment within two groups of barrier islands (Simpson Lagoon and Mikkelsen Bay) in the Beaufort Sea, Alaska. Nonrandom genetic associations were observed among nesting females using regional spatial autocorrelation analyses for distance classes up to 1000 m in Simpson Lagoon. Nearest-neighbour analyses identified clusters of genetically related females with positive lr values observed for 0-13% and 0-7% of the comparisons in Simpson Lagoon and Mikkelsen Bay, respectively, across years. These results indicate that a proportion of females are nesting in close proximity to more genetically related individuals, albeit at low frequency. Such kin groupings may form through active association between relatives or through natal philopatry and breeding site fidelity. Eiders nest in close association with driftwood, which is redistributed annually by seasonal storms. Yet, genetic associations were still observed. Microgeographic structure may thus be more attributable to kin association than natal philopatry and site fidelity. However, habitat availability may also influence the level of structure observed. Regional structure was present only within Simpson Lagoon and this island group includes at least three islands with sufficient driftwood for colonies, whereas only one island at Mikkelsen Bay has these features. A long-term demographic study is needed to understand more fully the mechanisms that lead to fine-scale genetic structure observed in common eiders breeding in the Beaufort Sea. ?? Published 2010. This article is a US Government work and is in the public domain in the USA.

  17. Influence of the Gulf Stream on the Barents Sea ice retreat and Eurasian coldness during early winter

    International Nuclear Information System (INIS)

    Sato, Kazutoshi; Inoue, Jun; Watanabe, Masahiro

    2014-01-01

    Abnormal sea-ice retreat over the Barents Sea during early winter has been considered a leading driver of recent midlatitude severe winters over Eurasia. However, causal relationships between such retreat and the atmospheric circulation anomalies remains uncertain. Using a reanalysis dataset, we found that poleward shift of a sea surface temperature front over the Gulf Stream likely induces warm southerly advection and consequent sea-ice decline over the Barents Sea sector, and a cold anomaly over Eurasia via planetary waves triggered over the Gulf Stream region. The above mechanism is supported by the steady atmospheric response to the diabatic heating anomalies over the Gulf Stream region obtained with a linear baroclinic model. The remote atmospheric response from the Gulf Stream would be amplified over the Barents Sea region via interacting with sea-ice anomaly, promoting the warm Arctic and cold Eurasian pattern. (letter)

  18. Arctic Sea Ice, Eurasia Snow, and Extreme Winter Haze in China

    Science.gov (United States)

    Zou, Y.; Wang, Y.; Xie, Z.; Zhang, Y.; Koo, J. H.

    2017-12-01

    Eastern China is experiencing more severe haze pollution in winter during recent years. Though the environmental deterioration in this region is usually attributed to the high intensity of anthropogenic emissions and large contributions from secondary aerosol formation, the impact of climate variability is also indispensable given its significant influence on regional weather systems and pollution ventilation. Here we analyzed the air quality related winter meteorological conditions over Eastern China in the last four decades and showed a worsening trend in poor regional air pollutant ventilation. Such variations increased the probability of extreme air pollution events, which is in good agreement with aerosol observations of recent years. We further identified the key circulation pattern that is conducive to the weakening ventilation and investigated the relationship between synoptic circulation changes and multiple climate forcing variables. Both statistical analysis and numerical sensitivity experiments suggested that the poor ventilation condition is linked to boreal cryosphere changes including Arctic sea ice in preceding autumn and Eurasia snowfall in earlier winter. We conducted comprehensive dynamic diagnosis and proposed a physical mechanism to explain the observed and simulated circulation changes. At last, we examined future projections of winter extreme stagnation events based on the CMIP5 projection data.

  19. Correlation analyses of Baltic Sea winter water mass formation and its impact on secondary and tertiary production

    Directory of Open Access Journals (Sweden)

    Jörn Schmidt

    2007-09-01

    Full Text Available The thermal stratification of the upper water layers in the BalticSea varies seasonally in response to the annual cycle of solarheating and wind-induced mixing. In winter, the stratificationdown to the halocline is almost completely eroded by convectionand strong wind mixing. Monthly averaged temperature profilesobtained from the ICES hydrographic database were used to studythe long-term variability (1950 to 2005 of winter water massformation in different deep basins of the Baltic Sea east ofthe island of Bornholm. Besides strong interannual variabilityof deep winter water temperatures, the last two decades showa positive trend (increase of 1-1.5°C. Correlationsof winter surface temperatures to temperatures of the winterwater body located directly above or within the top of the haloclinewere strongly positive until the autumn months. Such a closecoupling allows sea surface temperatures in winter to be usedto forecast the seasonal development of the thermal signaturein deeper layers with a high degree of confidence. The most significantimpact of winter sea surface temperatures on the thermal signaturein this depth range can be assigned to February/March. Strongersolar heating during spring and summer results in thermal stratificationof the water column leading to a complete decoupling of surfaceand deep winter water temperatures. Based on laboratory experiments,temperature-dependent relationships were utilised to analyseinterannual variations of biological processes with special emphasison the upper trophic levels (e.g., stage-specific developmentalrates of zooplankton and survival rates of fish eggs.

  20. Ikaite crystal distribution in Arctic winter sea ice and implications for CO2 system dynamics

    Science.gov (United States)

    Rysgaard, S.; Søgaard, D. H.; Cooper, M.; Pućko, M.; Lennert, K.; Papakyriakou, T. N.; Wang, F.; Geilfus, N. X.; Glud, R. N.; Ehn, J.; McGinnnis, D. F.; Attard, K.; Sievers, J.; Deming, J. W.; Barber, D.

    2012-12-01

    The precipitation of ikaite (CaCO3·6H2O) in polar sea ice is critical to the efficiency of the sea ice-driven carbon pump and potentially important to the global carbon cycle, yet the spatial and temporal occurrence of ikaite within the ice is poorly known. We report unique observations of ikaite in unmelted ice and vertical profiles of ikaite abundance and concentration in sea ice for the crucial season of winter. Ice was examined from two locations: a 1 m thick land-fast ice site and a 0.3 m thick polynya site, both in the Young Sound area (74° N, 20° W) of NE Greenland. Ikaite crystals, ranging in size from a few µm to 700 µm were observed to concentrate in the interstices between the ice platelets in both granular and columnar sea ice. In vertical sea-ice profiles from both locations, ikaite concentration determined from image analysis, decreased with depth from surfaceice values of 700-900 µmol kg-1 ice (~ 25 × 106 crystals kg-1) to bottom-layer values of 100-200 µmol kg-1 ice (1-7 × 106 kg-1), all of which are much higher (4-10 times) than those reported in the few previous studies. Direct measurements of total alkalinity (TA) in surface layers fell within the same range as ikaite concentration whereas TA concentrations in bottom layers were twice as high. This depth-related discrepancy suggests interior ice processes where ikaite crystals form in surface sea ice layers and partly dissolved in bottom layers. From these findings and model calculations we relate sea ice formation and melt to observed pCO2 conditions in polar surface waters, and hence, the air-sea CO2 flux.

  1. Interannual variation of the South China Sea circulation during winter: intensified in the southern basin

    Science.gov (United States)

    Zu, Tingting; Xue, Huijie; Wang, Dongxiao; Geng, Bingxu; Zeng, Lili; Liu, Qinyan; Chen, Ju; He, Yunkai

    2018-05-01

    Surface geostrophic current derived from altimetry remote sensing data, and current profiles observed from in-situ Acoustic Doppler Current Profilers (ADCP) mooring in the northern South China Sea (NSCS) and southern South China Sea (SSCS) are utilized to study the kinetic and energetic interannual variability of the circulation in the South China Sea (SCS) during winter. Results reveal a more significant interannual variation of the circulation and water mass properties in the SSCS than that in the NSCS. Composite ananlysis shows a significantly reduced western boundary current (WBC) and a closed cyclonic eddy in the SSCS at the mature phase of El Niño event, but a strong WBC and an unclosed cyclonic circulation in winter at normal or La Niña years. The SST is warmer while the subsurface water is colder and fresher in the mature phase of El Niño event than that in the normal or La Niña years in the SSCS. Numerical experiments and energy analysis suggest that both local and remote wind stress change are important for the interannual variation in the SSCS, remote wind forcing and Kuroshio intrusion affect the circulation and water mass properties in the SSCS through WBC advection.

  2. Differential response of winter cooling on biological production in the northeastern Arabian Sea and northwestern Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Jyothibabu, R.; Maheswaran, P.A; Madhu, N.V.; Asharaf, T.T.M.; Gerson, V.J.; Haridas, P.; Venugopal, P.; Revichandran, C.; Nair, K.K.C.; Gopalakrishnan, T.C.

    The northern parts of the twin seas bordering the Indian subcontinent, the Arabian Sea (AS) and Bay of Bengal (BOB), were studied during the winter monsoon. Higher biological production was observed in the AS (chlorophyll a 47.5 mg m sup(-2...

  3. Direct observations of atmosphere - sea ice - ocean interactions during Arctic winter and spring storms

    Science.gov (United States)

    Graham, R. M.; Itkin, P.; Granskog, M. A.; Assmy, P.; Cohen, L.; Duarte, P.; Doble, M. J.; Fransson, A.; Fer, I.; Fernandez Mendez, M.; Frey, M. M.; Gerland, S.; Haapala, J. J.; Hudson, S. R.; Liston, G. E.; Merkouriadi, I.; Meyer, A.; Muilwijk, M.; Peterson, A.; Provost, C.; Randelhoff, A.; Rösel, A.; Spreen, G.; Steen, H.; Smedsrud, L. H.; Sundfjord, A.

    2017-12-01

    To study the thinner and younger sea ice that now dominates the Arctic the Norwegian Young Sea ICE expedition (N-ICE2015) was launched in the ice-covered region north of Svalbard, from January to June 2015. During this time, eight local and remote storms affected the region and rare direct observations of the atmosphere, snow, ice and ocean were conducted. Six of these winter storms passed directly over the expedition and resulted in air temperatures rising from below -30oC to near 0oC, followed by abrupt cooling. Substantial snowfall prior to the campaign had already formed a snow pack of approximately 50 cm, to which the February storms contributed an additional 6 cm. The deep snow layer effectively isolated the ice cover and prevented bottom ice growth resulting in low brine fluxes. Peak wind speeds during winter storms exceeded 20 m/s, causing strong snow re-distribution, release of sea salt aerosol and sea ice deformation. The heavy snow load caused widespread negative freeboard; during sea ice deformation events, level ice floes were flooded by sea water, and at least 6-10 cm snow-ice layer was formed. Elevated deformation rates during the most powerful winter storms damaged the ice cover permanently such that the response to wind forcing increased by 60 %. As a result of a remote storm in April deformation processes opened about 4 % of the total area into leads with open water, while a similar amount of ice was deformed into pressure ridges. The strong winds also enhanced ocean mixing and increased ocean heat fluxes three-fold in the pycnocline from 4 to 12 W/m2. Ocean heat fluxes were extremely large (over 300 W/m2) during storms in regions where the warm Atlantic inflow is located close to surface over shallow topography. This resulted in very large (5-25 cm/day) bottom ice melt and in cases flooding due to heavy snow load. Storm events increased the carbon dioxide exchange between the atmosphere and ocean but also affected the pCO2 in surface waters

  4. Yellow Ducks Overboard! A Lesson in Geography and World Citizenship

    Science.gov (United States)

    Nagel, Paul; Beauboeuf, Donna

    2012-01-01

    This lesson was inspired by the book, "10 Little Rubber Ducks" by Eric Carle, which discusses ocean pollution. The book was inspired by an incident in 1992: A shipping container tumbled into the North Pacific Ocean, broke open, and 28,800 little rubber ducks (and other plastic bath toys) were lost at sea. The ducks were manufactured in China, and…

  5. Use of geolocators reveals previously unknown Chinese and Korean scaly-sided merganser wintering sites

    DEFF Research Database (Denmark)

    Soloveyva, Diana; Afanasiev, Vsevolod; Fox, James W.

    2012-01-01

    areas in successive years, suggesting winter fidelity to catchments if not specific sites. A single female from the adjacent Avvakumovka catchment wintered on saltwater in Korea, at least 1300 km east of Chinese wintering birds. Most sea duck species (Tribe Mergini) form pairs away from breeding areas......, suggesting that this high level of winter dispersal amongst close-nesting females is a potential mechanism to maintain gene flow in this threatened species that has specialist habitat requirements. Hence, female scaly-sided mergansers disperse widely from breeding areas, but show fidelity to nesting areas...

  6. Covariability of Central America/Mexico winter precipitation and tropical sea surface temperatures

    Science.gov (United States)

    Pan, Yutong; Zeng, Ning; Mariotti, Annarita; Wang, Hui; Kumar, Arun; Sánchez, René Lobato; Jha, Bhaskar

    2018-06-01

    In this study, the relationships between Central America/Mexico (CAM) winter precipitation and tropical Pacific/Atlantic sea surface temperatures (SSTs) are examined based on 68-year (1948-2015) observations and 59-year (1957-2015) atmospheric model simulations forced by observed SSTs. The covariability of the winter precipitation and SSTs is quantified using the singular value decomposition (SVD) method with observational data. The first SVD mode relates out-of-phase precipitation anomalies in northern Mexico and Central America to the tropical Pacific El Niño/La Niña SST variation. The second mode links a decreasing trend in the precipitation over Central America to the warming of SSTs in the tropical Atlantic, as well as in the tropical western Pacific and the tropical Indian Ocean. The first mode represents 67% of the covariance between the two fields, indicating a strong association between CAM winter precipitation and El Niño/La Niña, whereas the second mode represents 20% of the covariance. The two modes account for 32% of CAM winter precipitation variance, of which, 17% is related to the El Niño/La Niña SST and 15% is related to the SST warming trend. The atmospheric circulation patterns, including 500-hPa height and low-level winds obtained by linear regressions against the SVD SST time series, are dynamically consistent with the precipitation anomaly patterns. The model simulations driven by the observed SSTs suggest that these precipitation anomalies are likely a response to tropical SST forcing. It is also shown that there is significant potential predictability of CAM winter precipitation given tropical SST information.

  7. Physical and biological characteristics of the winter-summer transition in the Central Red Sea

    KAUST Repository

    Zarokanellos, Nikolaos

    2017-07-25

    The Central Red Sea (CRS) lies between two distinct hydrographic and atmospheric regimes. In the southern Red Sea, seasonal monsoon reversal regulates the exchange of water between the Red Sea and the Indian Ocean. In the northern Red Sea, intermediate and occasionally deep water are formed during winter to sustain the basin\\'s overturning circulation. Highly variable mesoscale eddies and the northward flowing eastern boundary current (EBC) determine the physical and biogeochemical characteristics of the CRS. Ship-based and glider observations in the CRS between March and June 2013 capture key features of the transition from winter to summer and depict the impact of the eddy activity on the EBC flow. Less saline and relatively warmer water of Indian Ocean origin reaches the CRS via the EBC. Initially, an anticyclonic eddy with diameter of 140 km penetrating to 150m depth with maximum velocities up to 30–35 cm s prevails in the CRS. This anticyclonic eddy appears to block or at least redirect the northward flow of the EBC. Dissipation of the eddy permits the near-coastal, northward flow of the EBC and gives place to a smaller cyclonic eddy with a diameter of about 50 km penetrating to 200 m depth. By the end of May, as the northerly winds become stronger and persistent throughout the basin, characteristic of the summer southwest monsoon wind regime, the EBC, and its associated lower salinity water became less evident, replaced by the saltier surface water that characterizes the onset of the summer stratification in the CRS.

  8. Physical control of interannual variations of the winter chlorophyll bloom in the northern Arabian Sea

    Directory of Open Access Journals (Sweden)

    M. G. Keerthi

    2017-08-01

    Full Text Available The northern Arabian Sea hosts a winter chlorophyll bloom, triggered by convective overturning in response to cold and dry northeasterly monsoon winds. Previous studies of interannual variations of this bloom only relied on a couple of years of data and reached no consensus on the associated processes. The current study aims at identifying these processes using both  ∼  10 years of observations (including remotely sensed chlorophyll data and physical parameters derived from Argo data and a 20-year-long coupled biophysical ocean model simulation. Despite discrepancies in the estimated bloom amplitude, the six different remotely sensed chlorophyll products analysed in this study display a good phase agreement at seasonal and interannual timescales. The model and observations both indicate that the interannual winter bloom fluctuations are strongly tied to interannual mixed layer depth anomalies ( ∼  0.6 to 0.7 correlation, which are themselves controlled by the net heat flux at the air–sea interface. Our modelling results suggest that the mixed layer depth control of the bloom amplitude ensues from the modulation of nutrient entrainment into the euphotic layer. In contrast, the model and observations both display insignificant correlations between the bloom amplitude and thermocline depth, which precludes a control of the bloom amplitude by daily dilution down to the thermocline depth, as suggested in a previous study.

  9. Ikaite crystal distribution in winter sea ice and implications for CO2 system dynamics

    Science.gov (United States)

    Rysgaard, S.; Søgaard, D. H.; Cooper, M.; Pućko, M.; Lennert, K.; Papakyriakou, T. N.; Wang, F.; Geilfus, N. X.; Glud, R. N.; Ehn, J.; McGinnis, D. F.; Attard, K.; Sievers, J.; Deming, J. W.; Barber, D.

    2013-04-01

    The precipitation of ikaite (CaCO3 ⋅ 6H2O) in polar sea ice is critical to the efficiency of the sea ice-driven carbon pump and potentially important to the global carbon cycle, yet the spatial and temporal occurrence of ikaite within the ice is poorly known. We report unique observations of ikaite in unmelted ice and vertical profiles of ikaite abundance and concentration in sea ice for the crucial season of winter. Ice was examined from two locations: a 1 m thick land-fast ice site and a 0.3 m thick polynya site, both in the Young Sound area (74° N, 20° W) of NE Greenland. Ikaite crystals, ranging in size from a few μm to 700 μm, were observed to concentrate in the interstices between the ice platelets in both granular and columnar sea ice. In vertical sea ice profiles from both locations, ikaite concentration determined from image analysis, decreased with depth from surface-ice values of 700-900 μmol kg-1 ice (~25 × 106 crystals kg-1) to values of 100-200 μmol kg-1 ice (1-7 × 106 crystals kg-1) near the sea ice-water interface, all of which are much higher (4-10 times) than those reported in the few previous studies. Direct measurements of total alkalinity (TA) in surface layers fell within the same range as ikaite concentration, whereas TA concentrations in the lower half of the sea ice were twice as high. This depth-related discrepancy suggests interior ice processes where ikaite crystals form in surface sea ice layers and partly dissolve in layers below. Melting of sea ice and dissolution of observed concentrations of ikaite would result in meltwater with a pCO2 of <15 μatm. This value is far below atmospheric values of 390 μatm and surface water concentrations of 315 μatm. Hence, the meltwater increases the potential for seawater uptake of CO2.

  10. Secondary sulfate is internally mixed with sea spray aerosol and organic aerosol in the winter Arctic

    Science.gov (United States)

    Kirpes, Rachel M.; Bondy, Amy L.; Bonanno, Daniel; Moffet, Ryan C.; Wang, Bingbing; Laskin, Alexander; Ault, Andrew P.; Pratt, Kerri A.

    2018-03-01

    Few measurements of aerosol chemical composition have been made during the winter-spring transition (following polar sunrise) to constrain Arctic aerosol-cloud-climate feedbacks. Herein, we report the first measurements of individual particle chemical composition near Utqiaġvik (Barrow), Alaska, in winter (seven sample days in January and February 2014). Individual particles were analyzed by computer-controlled scanning electron microscopy with energy dispersive X-ray spectroscopy (CCSEM-EDX, 24 847 particles), Raman microspectroscopy (300 particles), and scanning transmission X-ray microscopy with near-edge X-ray absorption fine structure spectroscopy (STXM-NEXAFS, 290 particles). Sea spray aerosol (SSA) was observed in all samples, with fresh and aged SSA comprising 99 %, by number, of 2.5-7.5 µm diameter particles, 65-95 % from 0.5-2.5 µm, and 50-60 % from 0.1-0.5 µm, indicating SSA is the dominant contributor to accumulation and coarse-mode aerosol during the winter. The aged SSA particles were characterized by reduced chlorine content with 94 %, by number, internally mixed with secondary sulfate (39 %, by number, internally mixed with both nitrate and sulfate), indicative of multiphase aging reactions during transport. There was a large number fraction (40 % of 1.0-4.0 µm diameter particles) of aged SSA during periods when particles were transported from near Prudhoe Bay, consistent with pollutant emissions from the oil fields participating in atmospheric processing of aerosol particles. Organic carbon and sulfate particles were observed in all samples and comprised 40-50 %, by number, of 0.1-0.4 µm diameter particles, indicative of Arctic haze influence. Soot was internally mixed with organic and sulfate components. All sulfate was mixed with organic carbon or SSA particles. Therefore, aerosol sources in the Alaskan Arctic and resulting aerosol chemical mixing states need to be considered when predicting aerosol climate effects, particularly cloud

  11. Late winter biogeochemical conditions under sea ice in the Canadian High Arctic

    Directory of Open Access Journals (Sweden)

    Helen S. Findlay

    2015-12-01

    Full Text Available With the Arctic summer sea-ice extent in decline, questions are arising as to how changes in sea-ice dynamics might affect biogeochemical cycling and phenomena such as carbon dioxide (CO2 uptake and ocean acidification. Recent field research in these areas has concentrated on biogeochemical and CO2 measurements during spring, summer or autumn, but there are few data for the winter or winter–spring transition, particularly in the High Arctic. Here, we present carbon and nutrient data within and under sea ice measured during the Catlin Arctic Survey, over 40 days in March and April 2010, off Ellef Ringnes Island (78° 43.11′ N, 104° 47.44′ W in the Canadian High Arctic. Results show relatively low surface water (1–10 m nitrate (<1.3 µM and total inorganic carbon concentrations (mean±SD=2015±5.83 µmol kg−1, total alkalinity (mean±SD=2134±11.09 µmol kg−1 and under-ice pCO2sw (mean±SD=286±17 µatm. These surprisingly low wintertime carbon and nutrient conditions suggest that the outer Canadian Arctic Archipelago region is nitrate-limited on account of sluggish mixing among the multi-year ice regions of the High Arctic, which could temper the potential of widespread under-ice and open-water phytoplankton blooms later in the season.

  12. Duck plague

    Science.gov (United States)

    Friend, M.

    1999-01-01

    Duck plague is caused by a herpesvirus. Infection often results in an acute, contagious, and fatal disease. As with many other herpesviruses, duck plague virus can establish inapparent infections in birds that survive exposure to it, a state referred to as latency. During latency, the virus cannot be detected by standard methods for virus isolation. Studies of domestic species of waterfowl have detected multiple strains of the virus that vary in their ability to cause disease and death. Little is known about the response of wild waterfowl to strain differences.Duck plague outbreaks are thought to be caused when birds that carry the virus shed it through fecal or oral discharge, thus releasing the virus into food and water with which susceptible birds may have contact. Experimental studies have demonstrated spontaneous virus shedding by duck plague carriers during spring. Changes in the duration of daylight and onset of breeding are thought to be physiological stresses that stimulate virus shedding at this time of year. The carriers are immune to the disease, but the virus shed by them causes infection and disease among susceptible waterfowl. Bird-to-bird contact and contact with virus that has contaminated the environment perpetuate an outbreak. Scavenging and decomposition of carcasses of infected birds also contaminate the environment by releasing viruses from tissues and body fluids. Virus transmission through the egg has been reported, but the role of the egg in the disease cycle remains to be resolved.

  13. Improvement in Simulation of Eurasian Winter Climate Variability with a Realistic Arctic Sea Ice Condition in an Atmospheric GCM

    Science.gov (United States)

    Lim, Young-Kwon; Ham, Yoo-Geun; Jeong, Jee-Hoon; Kug, Jong-Seong

    2012-01-01

    The present study investigates how much a realistic Arctic sea ice condition can contribute to improve simulation of the winter climate variation over the Eurasia region. Model experiments are set up using different sea ice boundary conditions over the past 24 years (i.e., 1988-2011). One is an atmospheric model inter-comparison (AMIP) type of run forced with observed sea-surface temperature (SST), sea ice, and greenhouse gases (referred to as Exp RSI), and the other is the same as Exp RSI except for the sea ice forcing, which is a repeating climatological annual cycle (referred to as Exp CSI). Results show that Exp RSI produces the observed dominant pattern of Eurasian winter temperatures and their interannual variation better than Exp CSI (correlation difference up to approx. 0.3). Exp RSI captures the observed strong relationship between the sea ice concentration near the Barents and Kara seas and the temperature anomaly across Eurasia, including northeastern Asia, which is not well captured in Exp CSI. Lagged atmospheric responses to sea ice retreat are examined using observations to understand atmospheric processes for the Eurasian cooling response including the Arctic temperature increase, sea-level pressure increase, upper-level jet weakening and cold air outbreak toward the mid-latitude. The reproducibility of these lagged responses by Exp RSI is also evaluated.

  14. Improvement in simulation of Eurasian winter climate variability with a realistic Arctic sea ice condition in an atmospheric GCM

    International Nuclear Information System (INIS)

    Lim, Young-Kwon; Ham, Yoo-Geun; Jeong, Jee-Hoon; Kug, Jong-Seong

    2012-01-01

    The present study investigates how much a realistic Arctic sea ice condition can contribute to improve simulation of the winter climate variation over the Eurasia region. Model experiments are set up using different sea ice boundary conditions over the past 24 years (i.e., 1988–2011). One is an atmospheric model inter-comparison (AMIP) type of run forced with observed sea-surface temperature (SST), sea ice, and greenhouse gases (referred to as Exp RSI), and the other is the same as Exp RSI except for the sea ice forcing, which is a repeating climatological annual cycle (referred to as Exp CSI). Results show that Exp RSI produces the observed dominant pattern of Eurasian winter temperatures and their interannual variation better than Exp CSI (correlation difference up to ∼0.3). Exp RSI captures the observed strong relationship between the sea ice concentration near the Barents and Kara seas and the temperature anomaly across Eurasia, including northeastern Asia, which is not well captured in Exp CSI. Lagged atmospheric responses to sea ice retreat are examined using observations to understand atmospheric processes for the Eurasian cooling response including the Arctic temperature increase, sea-level pressure increase, upper-level jet weakening and cold air outbreak toward the mid-latitude. The reproducibility of these lagged responses by Exp RSI is also evaluated. (letter)

  15. White Sea's Severe Winter Hydrological Hazard and Its Effect On Decrease of Population of Greenland Seals (1998/99 Winter Ecological Catastrophe)

    Science.gov (United States)

    Melentyev, Konstantin V.; Chernook, Vladimir I.

    Types of hydrological hazards are various but its agencies are especially diversified . At this study hazard effects will be assessed for White Sea population of Greenland seals - a representatives of high level of marine fodder chains and the prime part of the Arctic nature. Number of population and type of their migration are strongly depended from different meteorological and hydrological parameters and processes, climate change and anthropogenical press, including pollution and fur-seal fishery, create additional problems. Especially hard situation happens now with the ice- associated sea mammals (p olar bear, seal, walrus, etc.). Mass destruction of seals in the White Sea (ecological catastrophe) which happens periodically is close connected with different kind of meteorological and hydrological hazard. Greenland seals selected these water areas for whelping where a rookeries are organized on pack ice. But severe winter conditions (long-run severe frosts and NE winds) can modify ice regime of the White Sea which lead to effect "blocking" of pack ice (and whelping rookeries) inside the "Basin". These features stimulated strong reduction number ofseals (especially pups). Marine biology use modelling of the system "sea mammal-media", study "behavior factors" and mammals biodiversity at the different natural conditions. But the main critical goal is the development of special observational network for the White Sea and contiguous regions. A contemporary technologies assume integration of remote sensing and in situ hydro-chemical measurements. Airborne IR and visible observation of the marginal Arctic seas became now an indispensable part of marine ecological investigations. Application of satellite data for monitoring of sea mammals has been attractive also but practical use is restrained by its small spatial resolution, daytime illumination and cloud influence in the Arctic. Launching ERS synthetic aperture radar (SAR) in 1991, which provides global all- weather

  16. Modeling a typical winter-time dust event over the Arabian Peninsula and the Red Sea

    Directory of Open Access Journals (Sweden)

    S. Kalenderski

    2013-02-01

    Full Text Available We used WRF-Chem, a regional meteorological model coupled with an aerosol-chemistry component, to simulate various aspects of the dust phenomena over the Arabian Peninsula and Red Sea during a typical winter-time dust event that occurred in January 2009. The model predicted that the total amount of emitted dust was 18.3 Tg for the entire dust outburst period and that the two maximum daily rates were ~2.4 Tg day−1 and ~1.5 Tg day−1, corresponding to two periods with the highest aerosol optical depth that were well captured by ground- and satellite-based observations. The model predicted that the dust plume was thick, extensive, and mixed in a deep boundary layer at an altitude of 3–4 km. Its spatial distribution was modeled to be consistent with typical spatial patterns of dust emissions. We utilized MODIS-Aqua and Solar Village AERONET measurements of the aerosol optical depth (AOD to evaluate the radiative impact of aerosols. Our results clearly indicated that the presence of dust particles in the atmosphere caused a significant reduction in the amount of solar radiation reaching the surface during the dust event. We also found that dust aerosols have significant impact on the energy and nutrient balances of the Red Sea. Our results showed that the simulated cooling under the dust plume reached 100 W m−2, which could have profound effects on both the sea surface temperature and circulation. Further analysis of dust generation and its spatial and temporal variability is extremely important for future projections and for better understanding of the climate and ecological history of the Red Sea.

  17. Modeling a typical winter-time dust event over the Arabian Peninsula and the Red Sea

    KAUST Repository

    Kalenderski, Stoitchko

    2013-02-20

    We used WRF-Chem, a regional meteorological model coupled with an aerosol-chemistry component, to simulate various aspects of the dust phenomena over the Arabian Peninsula and Red Sea during a typical winter-time dust event that occurred in January 2009. The model predicted that the total amount of emitted dust was 18.3 Tg for the entire dust outburst period and that the two maximum daily rates were ?2.4 Tg day-1 and ?1.5 Tg day-1, corresponding to two periods with the highest aerosol optical depth that were well captured by ground-and satellite-based observations. The model predicted that the dust plume was thick, extensive, and mixed in a deep boundary layer at an altitude of 3-4 km. Its spatial distribution was modeled to be consistent with typical spatial patterns of dust emissions. We utilized MODIS-Aqua and Solar Village AERONET measurements of the aerosol optical depth (AOD) to evaluate the radiative impact of aerosols. Our results clearly indicated that the presence of dust particles in the atmosphere caused a significant reduction in the amount of solar radiation reaching the surface during the dust event. We also found that dust aerosols have significant impact on the energy and nutrient balances of the Red Sea. Our results showed that the simulated cooling under the dust plume reached 100 W m-2, which could have profound effects on both the sea surface temperature and circulation. Further analysis of dust generation and its spatial and temporal variability is extremely important for future projections and for better understanding of the climate and ecological history of the Red Sea.

  18. Winter monsoon circulation of the northern Arabian Sea and Somali Current

    Science.gov (United States)

    Schott, Friedrich A.; Fischer, Jürgen

    2000-03-01

    The winter monsoon circulation in the northern inflow region of the Somali Current is discussed on the basis of an array of moored acoustic Doppler current profiler and current meter stations deployed during 1995-1996 and a ship survey carried out in January 1998. It is found that the westward inflow into the Somali Current regime occurs essentially south of 11°N and that this inflow bifurcates at the Somali coast, with the southward branch supplying the equatorward Somali Current and the northward one returning into the northwestern Arabian Sea. This northward branch partially supplies a shallow outflow through the Socotra Passage between the African continent and the banks of Socotra and partially feeds into eastward recirculation directly along the southern slopes of Socotra. Underneath this shallow surface flow, southwestward undercurrent flows are observed. Undercurrent inflow from the Gulf of Aden through the Socotra Passage occurs between 100 and 1000 m, with its current core at 700-800 m, and is clearly marked by the Red Sea Water (RSW) salinity maximum. The observations suggest that the maximum RSW inflow out of the Gulf of Aden occurs during the winter monsoon season and uses the Socotra Passage as its main route into the Indian Ocean. Westward undercurrent inflow into the Somali Current regime is also observed south of Socotra, but this flow lacks the RSW salinity maximum. Off the Arabian peninsula, eastward boundary flow is observed in the upper 800 m with a compensating westward flow to the south. The observed circulation pattern is qualitatively compared with recent high-resolution numerical model studies and is found to be in basic agreement.

  19. Intrusion of the Bay of Bengal water into the Arabian Sea during winter monsoon and associated chemical and biological response

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Narvekar, J.; Kumar, A.; Shaji, C.; Anand, P.; Sabu, P.; Rijomon, G.; Josia, J.; Jayaraj, K.A.; Radhika, A.; Nair, K.K.C.

    off. The hydrological imbalance thus created on an annual scale will have to be balanced by the inter-basin exchange. In winter this happens through the intrusion of Bay of Bengal waters into the Arabian Sea, when the southward flowing East India...

  20. Organochlorine and trace element contamination in wintering and migrating diving ducks in the southern Great Lakes, USA, since the zebra mussel invasion

    Science.gov (United States)

    Custer, Christine M.; Custer, T.W.

    2000-01-01

    Because of the potential for increased trophic transfer of contaminants by zebra mussels (Dreissena sp.) to higher trophic levels, we collected four species of waterfowl (n = 65 ducks) from four locations in Lake Erie, Lake St. Clair, and Lake Michigan, USA, between 1991 and 1993 for organochlorine contaminant and trace element analyses. Geometric mean concentrations of total polychlorinated biphenyls (PCBs) and p,pa??-dichlorodiphenyldichloroethylene (DDE) were 1.35 and 0.15 I?g/g wet weight in lesser scaup (Aythya affinis) carcasses and were below known effect levels. Total PCBs in 80% of carcasses, however, were above the U.S. Food and Drug Administration's threshold of 3.0 I?g/g lipid weight for consumption of poultry. With the exception of selenium, trace elements were also at background or no-effect levels. Selenium concentrations in livers of 95% of lesser scaup, 90% of bufflehead (Bucephala albeola), and 72% of common goldeneye (Bucephala clangula) were in the elevated (>10 I?g/g dry wt) or potentially harmful range (>33 I?g/g dry wt). The effects of these high selenium concentrations are unknown but should be investigated further based on reproductive effects observed in field and laboratory studies of dabbling ducks and because lesser scaup populations are declining. Concentrations of total PCBs in dreissenid mussels in western Lake Erie were 10 times higher than in the upper Mississippi River but were similar to concentrations in other industrialized rivers in Europe and the United States. Metal concentrations were similar to other industrialized sites where zebra mussels have been sampled.

  1. Winter distribution of euphausiids ( Euphausiacea) in the Barents Sea (2000-2005)

    Science.gov (United States)

    Zhukova, Natalia G.; Nesterova, Valentina N.; Prokopchuk, Irina P.; Rudneva, Galina B.

    2009-10-01

    The purpose of the study is to analyze the state of the Barents Sea euphausiids populations in the warm period (2000-2005) based on the study of their structure dynamics and distribution under the influence of abiotic and biotic factors. For estimation of their aggregations in the bottom layer, the traditional method was used with the help of the modified egg net (0.2 m 2 opening area, 564 μm mesh size). The net is used for collecting euphausiids in the autumn-winter period when their activity is reduced, which results in high-catch efficiency. The findings confirmed the major formation patterns of the euphausiids species composition associated with climate change in the Arctic basin. As before, in the warm years, one can see a clear-cut differentiation of space distribution of the dominant euphausiids Thysanoessa genus with localization of the more thermophilic Thysanoessa inermis in the north-west Barents Sea and Thysanoessa raschii in the east. The major euphausiids aggregations are formed of these species. In 2004, the first data of euphausiids distribution in the northern Barents Sea (77-79°N) were obtained, and demonstrated extremely high concentrations of T. inermis in this area, with the biomass as high as 1.7-2.4 g m -2 in terms of dry weight. These data have improved our knowledge of the distribution and euphausiids abundance during periods of elevated sea-water temperatures in the Barents Sea. The oceanic Atlantic species were found to increase in abundance due to elevated advection to the Barents Sea during the study period. Thus, after nearly a 30-year-long absence of the moderate subtropical Nematoscelis megalops in the Barents Sea, they were found again in 2003-2005. However in comparison with 1960, the north-east border of its distribution considerably shifted to 73°50'N 50°22'E. The portion of Meganyctiphanes norvegica also varied considerably—from 10% to 20% of the total euphausiids population in the warm 1950s-1960s almost to complete

  2. The Impact of Cloud Properties on Young Sea Ice during Three Winter Storms at N-ICE2015

    Science.gov (United States)

    Murphy, S. Y.; Walden, V. P.; Cohen, L.; Hudson, S. R.

    2017-12-01

    The impact of clouds on sea ice varies significantly as cloud properties change. Instruments deployed during the Norwegian Young Sea Ice field campaign (N-ICE2015) are used to study how differing cloud properties influence the cloud radiative forcing at the sea ice surface. N-ICE2015 was the first campaign in the Arctic winter since SHEBA (1997/1998) to study the surface energy budget of sea ice and the associated effects of cloud properties. Cloud characteristics, surface radiative and turbulent fluxes, and meteorological properties were measured throughout the field campaign. Here we explore how cloud macrophysical and microphysical properties affect young, thin sea ice during three winter storms from 31 January to 15 February 2015. This time period is of interest due to the varying surface and atmospheric conditions, which showcase the variety of conditions the newly-formed sea ice can experience during the winter. This period was characterized by large variations in the ice surface and near-surface air temperatures, with highs near 0°C when warm, moist air was advected into the area and lows reaching -40°C during clear, calm periods between storms. The advection of warm, moist air into the area influenced the cloud properties and enhanced the downwelling longwave flux. For most of the period, downwelling longwave flux correlates closely with the air temperature. However, at the end of the first storm, a drop in downwelling longwave flux of about 50 Wm-2 was observed, independent of any change in surface or air temperature or cloud fraction, indicating a change in cloud properties. Lidar data show an increase in cloud height during this period and a potential shift in cloud phase from ice to mixed-phase. This study will describe the cloud properties during the three winter storms and discuss their impacts on surface energy budget.

  3. Characteristics of Winter Surface Air Temperature Anomalies in Moscow in 1970-2016 under Conditions of Reduced Sea Ice Area in the Barents Sea

    Science.gov (United States)

    Shukurov, K. A.; Semenov, V. A.

    2018-01-01

    On the basis of observational data on daily mean surface air temperature (SAT) and sea ice concentration (SIC) in the Barents Sea (BS), the characteristics of strong positive and negative winter SAT anomalies in Moscow have been studied in comparison with BS SIC data obtained in 1949-2016. An analysis of surface backward trajectories of air-particle motions has revealed the most probable paths of both cold and warm air invasions into Moscow and located regions that mostly affect strong winter SAT anomalies in Moscow. Atmospheric circulation anomalies that cause strong winter SAT anomalies in Moscow have been revealed. Changes in the ways of both cold and warm air invasions have been found, as well as an increase in the frequency of blocking anticyclones in 2005-2016 when compared to 1970-1999. The results suggest that a winter SIC decrease in the BS in 2005-2016 affects strong winter SAT anomalies in Moscow due to an increase in the frequency of occurrence of blocking anticyclones to the south of and over the BS.

  4. Large-Scale Microzooplankton Abundance and Diversity in the North Sea in Mid-Winter

    Science.gov (United States)

    Bils, F.; Moyano, M.; Peck, M. A.

    2016-02-01

    Protists and other microzooplankters (20-200 µm) are often not sampled in ecosystem monitoring programs despite the trophodynamic importance of this size fraction as grazers in the microbial loop and as prey for larger zooplankton and early larval stages of fish. We investigated the microzooplankton composition, diversity and abundance at 40 stations across the North Sea (from 3.2° W-7.6° E and 50.5-59.8°N) in mid-winter of 2014. Microzooplankton was collected with a CTD rosette at 10 m depth and manually counted and identified to the lowest possible taxa. A total of 35 taxa of dinoflagellates and ciliates was identified. Gymnodinium spp and Torodinium sp contributed most to the total dinoflagellate abundance (34 and 24 %) and Strombidium spp was the most abundant ciliate taxon (52 % of total ciliate abundance). Total microzooplankton biomass ranged between 0.08 and 2.4 µg C *L-1, much lower than those observed in spring or summer (up to > 100 µgC L-1). The highest biomass (> 0.5 µgC L-1) were found in the English Channel, south of 52°N, in contrast with those calculated for stations north of 57°N (< 0.2 µgC L-1). Changes in the community composition will be discussed in relation to observed gradients in hydrographic conditions and the ability of microzooplankton to support dietary requirements of overwintering larvae of marine fishes.

  5. The value of Inuit participation when conserving the common eider duck in Arctic Canada and Greenland

    DEFF Research Database (Denmark)

    Gilchrist, Grant; Merkel, Flemming Ravn; Sonne, Christian

    , Denmark, and northerners. This presentation will review the meaningful involvement and direct participation of Inuit during many aspects of historical and ongoing eider duck conservation efforts. These include studies that examined the sustainability of harvest, the establishment of new harvest......The northern common eider duck nests in the eastern Canadian Arctic and west Greenland, and migrates to winter in Atlantic Canada and southwest Greenland. The eider is harvested for its meat, feather down and eggs and its ongoing conservation is the shared responsibility of Canada, Greenland...... regulations, long term monitoring of breeding colonies in remote coastal locations, reporting on emerging disease epidemics, and ongoing field studies which examine the impacts of polar bear predation under changing sea ice conditions. This presentation will review how working relationships were established...

  6. Delineation of marine ecosystem zones in the northern Arabian Sea during winter

    Directory of Open Access Journals (Sweden)

    S. Shalin

    2018-03-01

    Full Text Available The spatial and temporal variability of marine autotrophic abundance, expressed as chlorophyll concentration, is monitored from space and used to delineate the surface signature of marine ecosystem zones with distinct optical characteristics. An objective zoning method is presented and applied to satellite-derived Chlorophyll a (Chl a data from the northern Arabian Sea (50–75° E and 15–30° N during the winter months (November–March. Principal component analysis (PCA and cluster analysis (CA were used to statistically delineate the Chl a into zones with similar surface distribution patterns and temporal variability. The PCA identifies principal components of variability and the CA splits these into zones based on similar characteristics. Based on the temporal variability of the Chl a pattern within the study area, the statistical clustering revealed six distinct ecological zones. The obtained zones are related to the Longhurst provinces to evaluate how these compared to established ecological provinces. The Chl a variability within each zone was then compared with the variability of oceanic and atmospheric properties viz. mixed-layer depth (MLD, wind speed, sea-surface temperature (SST, photosynthetically active radiation (PAR, nitrate and dust optical thickness (DOT as an indication of atmospheric input of iron to the ocean. The analysis showed that in all zones, peak values of Chl a coincided with low SST and deep MLD. The rate of decrease in SST and the deepening of MLD are observed to trigger the algae bloom events in the first four zones. Lagged cross-correlation analysis shows that peak Chl a follows peak MLD and SST minima. The MLD time lag is shorter than the SST lag by 8 days, indicating that the cool surface conditions might have enhanced mixing, leading to increased primary production in the study area. An analysis of monthly climatological nitrate values showed increased concentrations associated with the deepening

  7. Delineation of marine ecosystem zones in the northern Arabian Sea during winter

    Science.gov (United States)

    Shalin, Saleem; Samuelsen, Annette; Korosov, Anton; Menon, Nandini; Backeberg, Björn C.; Pettersson, Lasse H.

    2018-03-01

    The spatial and temporal variability of marine autotrophic abundance, expressed as chlorophyll concentration, is monitored from space and used to delineate the surface signature of marine ecosystem zones with distinct optical characteristics. An objective zoning method is presented and applied to satellite-derived Chlorophyll a (Chl a) data from the northern Arabian Sea (50-75° E and 15-30° N) during the winter months (November-March). Principal component analysis (PCA) and cluster analysis (CA) were used to statistically delineate the Chl a into zones with similar surface distribution patterns and temporal variability. The PCA identifies principal components of variability and the CA splits these into zones based on similar characteristics. Based on the temporal variability of the Chl a pattern within the study area, the statistical clustering revealed six distinct ecological zones. The obtained zones are related to the Longhurst provinces to evaluate how these compared to established ecological provinces. The Chl a variability within each zone was then compared with the variability of oceanic and atmospheric properties viz. mixed-layer depth (MLD), wind speed, sea-surface temperature (SST), photosynthetically active radiation (PAR), nitrate and dust optical thickness (DOT) as an indication of atmospheric input of iron to the ocean. The analysis showed that in all zones, peak values of Chl a coincided with low SST and deep MLD. The rate of decrease in SST and the deepening of MLD are observed to trigger the algae bloom events in the first four zones. Lagged cross-correlation analysis shows that peak Chl a follows peak MLD and SST minima. The MLD time lag is shorter than the SST lag by 8 days, indicating that the cool surface conditions might have enhanced mixing, leading to increased primary production in the study area. An analysis of monthly climatological nitrate values showed increased concentrations associated with the deepening of the mixed layer. The

  8. Origin and pathways of Winter Intermediate Water in the Northwestern Mediterranean Sea using observations and numerical simulation

    Science.gov (United States)

    Juza, Mélanie; Renault, Lionel; Ruiz, Simon; Tintoré, Joaquin

    2013-12-01

    The study of water masses worldwide (their formation, spreading, mixing, and impact on general circulation) is essential for a better understanding of the ocean circulation and variability. In this paper, the formation and main pathways of Winter Intermediate Water (WIW) in the Northwestern Mediterranean Sea (NWMED) are investigated during the winter-spring 2011 using observations and numerical simulation. The main results show that the WIW, formed along the continental shelves of the Gulf of Lion and Balearic Sea, circulates southward following five preferential pathways depending on the WIW formation site location and the oceanic conditions. WIW joins the northeastern part of the Balearic Sea, or flows along the continental shelves until joining the Balearic Current (maximum of 0.33 Sv in early-April) or further south until the Ibiza Channel entrance. Two additional trajectories, contributing to water mass exchanges with the southern part of the Western Mediterranean Sea, bring the WIW through the Ibiza and Mallorca Channels (maxima of 0.26 Sv in late-March and 0.1 Sv in early-April, respectively). The circulation of WIW over the NWMED at 50-200 m depth, its mixing and spreading over the Western Mediterranean Sea (reaching the south of the Balearic Islands, the Algero-Provencal basin, the Ligurian and the Alboran Seas) suggest that the WIW may have an impact on the ocean circulation by eddy blocking effect, exchange of water masses between north and south subbasins of Western Mediterranean Sea through the Ibiza Channel or modification of the ocean stratification.

  9. Frost flowers and sea-salt aerosols over seasonal sea-ice areas in northwestern Greenland during winter-spring

    Science.gov (United States)

    Hara, Keiichiro; Matoba, Sumito; Hirabayashi, Motohiro; Yamasaki, Tetsuhide

    2017-07-01

    Sea salts and halogens in aerosols, frost flowers, and brine play an important role in atmospheric chemistry in polar regions. Simultaneous sampling and observations of frost flowers, brine, and aerosol particles were conducted around Siorapaluk in northwestern Greenland during December 2013 to March 2014. Results show that water-soluble frost flower and brine components are sea-salt components (e.g., Na+, Cl-, Mg2+, K+, Ca2+, Br-, and iodine). Concentration factors of sea-salt components of frost flowers and brine relative to seawater were 1.14-3.67. Sea-salt enrichment of Mg2+, K+, Ca2+, and halogens (Cl-, Br-, and iodine) in frost flowers is associated with sea-salt fractionation by precipitation of mirabilite and hydrohalite. High aerosol number concentrations correspond to the occurrence of higher abundance of sea-salt particles in both coarse and fine modes, and blowing snow and strong winds. Aerosol number concentrations, particularly in coarse mode, are increased considerably by release from the sea-ice surface under strong wind conditions. Sulfate depletion by sea-salt fractionation was found to be limited in sea-salt aerosols because of the presence of non-sea-salt (NSS) SO42-. However, coarse and fine sea-salt particles were found to be rich in Mg. Strong Mg enrichment might be more likely to proceed in fine sea-salt particles. Magnesium-rich sea-salt particles might be released from the surface of snow and slush layer (brine) on sea ice and frost flowers. Mirabilite-like and ikaite-like particles were identified only in aerosol samples collected near new sea-ice areas. From the field evidence and results from earlier studies, we propose and describe sea-salt cycles in seasonal sea-ice areas.

  10. Inter-Relationship Between Subtropical Pacific Sea Surface Temperature, Arctic Sea Ice Concentration, and the North Atlantic Oscillation in Recent Summers and Winters

    Science.gov (United States)

    Lim, Young-Kwon; Cullather, Richard I.; Nowicki, Sophie M.; Kim, Kyu-Myong

    2017-01-01

    The inter-relationship between subtropical western-central Pacific sea surface temperatures (STWCPSST), sea ice concentration in the Beaufort Sea (SICBS), and the North Atlantic Oscillation (NAO) are investigated for the last 37 summers and winters (1980-2016). Lag-correlation of the STWCPSST×(-1) in spring with the NAO phase and SICBS in summer increases over the last two decades, reaching r = 0.4-0.5 with significance at 5 percent, while winter has strong correlations in approximately 1985-2005. Observational analysis and the atmospheric general circulation model experiments both suggest that STWCPSST warming acts to increase the Arctic geopotential height and temperature in the following season. This atmospheric response extends to Greenland, providing favorable conditions for developing the negative phase of the NAO. SIC and surface albedo tend to decrease over the Beaufort Sea in summer, linked to the positive surface net shortwave flux. Energy balance considering radiative and turbulent fluxes reveal that available energy that can heat surface is larger over the Arctic and Greenland and smaller over the south of Greenland, in response to the STWCPSST warming in spring. XXXX Arctic & Atlantic: Positive upper-level height/T anomaly over the Arctic and Greenland, and a negative anomaly over the central-eastern Atlantic, resembling the (-) phase of the NAO. Pacific: The negative height/T anomaly over the mid-latitudes, along with the positive anomaly over the STWCP, where 1degC warming above climatology is prescribed. Discussion: It is likely that the Arctic gets warm and the NAO is in the negative phase in response to the STWCP warming. But, there are other factors (e.g., internal variability) that contribute to determination of the NAO phase: not always the negative phase of the NAO in the event of STWCP warming (e.g.: recent winters and near neutral NAO in 2017 summer).

  11. Meteorological conditions in a thinner Arctic sea ice regime from winter to summer during the Norwegian Young Sea Ice expedition (N-ICE2015)

    Science.gov (United States)

    Cohen, Lana; Hudson, Stephen R.; Walden, Von P.; Graham, Robert M.; Granskog, Mats A.

    2017-07-01

    Atmospheric measurements were made over Arctic sea ice north of Svalbard from winter to early summer (January-June) 2015 during the Norwegian Young Sea Ice (N-ICE2015) expedition. These measurements, which are available publicly, represent a comprehensive meteorological data set covering the seasonal transition in the Arctic Basin over the new, thinner sea ice regime. Winter was characterized by a succession of storms that produced short-lived (less than 48 h) temperature increases of 20 to 30 K at the surface. These storms were driven by the hemispheric scale circulation pattern with a large meridional component of the polar jet stream steering North Atlantic storms into the high Arctic. Nonstorm periods during winter were characterized by strong surface temperature inversions due to strong radiative cooling ("radiatively clear state"). The strength and depth of these inversions were similar to those during the Surface Heat Budget of the Arctic Ocean (SHEBA) campaign. In contrast, atmospheric profiles during the "opaquely cloudy state" were different to those from SHEBA due to differences in the synoptic conditions and location within the ice pack. Storm events observed during spring/summer were the result of synoptic systems located in the Barents Sea and the Arctic Basin rather than passing directly over N-ICE2015. These synoptic systems were driven by a large-scale circulation pattern typical of recent years, with an Arctic Dipole pattern developing during June. Surface temperatures became near-constant 0°C on 1 June marking the beginning of summer. Atmospheric profiles during the spring and early summer show persistent lifted temperature and moisture inversions that are indicative of clouds and cloud processes.

  12. Effects of lead structure in Bering Sea pack ice on the flight costs of wintering spectacled eiders

    Science.gov (United States)

    Bump, Joseph K.; Lovvorn, James R.

    2004-10-01

    In polar regions, sea ice is critical habitat for many marine birds and mammals. The quality of pack ice habitat depends on the duration and spacing of leads (openings in the ice), which determine access to water and air for diving endotherms, and how often and how far they must move as leads open and close. Recent warming trends have caused major changes in the extent and nature of sea ice at large scales used in climate models. However, no studies have analyzed lead structure in terms of habitat for ice-dependent endotherms, or effects of climate on ice habitat at scales relevant to their daily movements. Based on observations from an icebreaker and synthetic aperture radar (SAR) images, we developed methods to describe the dynamics and thermodynamics of lead structure relative to use by spectacled eiders ( Somateria fischeri) wintering in pack ice of the Bering Sea. By correlating lead structure with weather variables, we then used these methods to estimate changes in lead dynamics from 1945 to 2002, and effects of such changes on flight costs of the eiders. For 1991-1992, when images were available about every 3 days throughout winter, SAR images were divided among five weather regimes defined by wind speed, wind direction, and air temperature. Based on 12.5-m pixels, lead shape, compass orientation, and fetch across leads did not differ among the weather regimes. However, the five regimes differed in total area of open water, leads per unit area, and distance between leads. Lead duration was modeled based on air temperature, wind, and fetch. Estimates of mean daily flight time for eiders, based on lead duration and distance between neighboring leads, differed among regimes by 0 to 15 min. Resulting flight costs varied from 0 to 158 kJ day -1, or from 0% to 11% of estimated field metabolic rate. Over 57 winters (1945-2002), variation among years in mean daily flight time was most influenced by the north-south wind component, which determined pack divergence

  13. South China Sea Wave Characteristics During Typhoon Muifa Passage in Winter 2004

    National Research Council Canada - National Science Library

    Chu, Peter C; Cheng, Kuo-Feng

    2008-01-01

    Ocean wave characteristics in the western Atlantic Ocean (Hurricane Region) to tropical cyclones have been investigated extensively, but not the regional seas in the western Pacific such as the South China Sea (Typhoon Region...

  14. Mechanism of the biological response to winter cooling in the northeastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; PrasannaKumar, S.; Bhattathiri, P.M.A.; DileepKumar, M.; Raghukumar, S.; Nair, K.K.C.; Ramaiah, N.

    The Arabian Sea is one of the most biologically productive ocean regions, mainly due to the upwelling of nutrients during the summer (southwest) monsoon. But the northern Arabian Sea continues to sustain fairly high biological production after...

  15. Retrospective analysis of seasonal ocean growth rates of two sea winter Atlantic Salmon in eastern Maine using historic scales

    Science.gov (United States)

    Izzo, Lisa K.; Zydlewski, Joseph D.

    2017-01-01

    Substantial declines of anadromous Atlantic Salmon Salmo salar have occurred throughout its range, with many populations at the southern extent of the distribution currently extirpated or endangered. While both one sea winter (1SW) and two sea winter (2SW) spawner numbers for the North American stocks have declined since the 1950s, the decline has been most severe in 2SW spawners. The first months at sea are considered a period of high mortality. However, early ocean mortality alone cannot explain the more pronounced decline of 2SW spawners, suggesting that the second year at sea may be more critical than previously thought. Atlantic Salmon scales collected by anglers and the state agency from 1946 to 2013 from five rivers in eastern Maine were used to estimate smolt age and ocean age of returning adults. Additionally, seasonal growth rates of maiden 2SW spawners were estimated using intercirculi measurements and linear back-calculation methods. Generalized linear mixed models (Gaussian family, log link function) were used to investigate the influence of average sea surface temperature, accumulated thermal units, the Atlantic Multidecadal Oscillation (AMO) and North Atlantic Oscillation indices, smolt age, smolt length, postsmolt growth, and river of origin on growth rate during the oceanic migration of North American Atlantic Salmon. Results suggest that different factors influence salmon growth throughout their oceanic migration, and previous growth can be a strong predictor of future size. Growth was negatively impacted by the phase of the AMO, which has been linked to salmon abundance trends, in early spring following the postsmolt period. This is likely when the 1SW and 2SW stock components separate, and our results suggest that this period may be of interest in future work examining the disproportionate decline in 2SW spawners.

  16. MULTIVARIATE ANALYSIS OF THE MORPHOLOGICAL TRAITS OF FEMALE DUCK, MUSCOVY-DUCK AND MULE-DUCK

    Directory of Open Access Journals (Sweden)

    S. Johari

    2014-10-01

    Full Text Available The objective of this study was to evaluate the characteristics of morphometrical measurements inthe female waterfowls. The animals used in this research were 90 ducks , 90 muscovy-ducks and 90mule-ducks in Bulukumba district of Brebes regency, Central Java, Indonesia. Parameters measuredwere maxilla length, neck length, body length, chest circumstance, wing length, chest length, femurlength and tibia length. The data were analyzed using the Statistical Analysis System ver. 9.1. Muscovyduckgenerally had the largest of size, followed by mule-duck and then duck. The most discriminantvariables were showed by chest length and chest circumstance. Muscovy-duck and mule-duck hadclosest genetic distance (3.974870 than both of the distance between duck and mule duck (14.10, andmuscovy-duck and duck (24.73. The smallest errorness level in grouping was showed in duck 1%followed by 2% in mule-duck and 3% in muscovy-duck.

  17. Sea surface salinity and temperature-based predictive modeling of southwestern US winter precipitation: improvements, errors, and potential mechanisms

    Science.gov (United States)

    Liu, T.; Schmitt, R. W.; Li, L.

    2017-12-01

    Using 69 years of historical data from 1948-2017, we developed a method to globally search for sea surface salinity (SSS) and temperature (SST) predictors of regional terrestrial precipitation. We then applied this method to build an autumn (SON) SSS and SST-based 3-month lead predictive model of winter (DJF) precipitation in southwestern United States. We also find that SSS-only models perform better than SST-only models. We previously used an arbitrary correlation coefficient (r) threshold, |r| > 0.25, to define SSS and SST predictor polygons for best subset regression of southwestern US winter precipitation; from preliminary sensitivity tests, we find that |r| > 0.18 yields the best models. The observed below-average precipitation (0.69 mm/day) in winter 2015-2016 falls within the 95% confidence interval of the prediction model. However, the model underestimates the anomalous high precipitation (1.78 mm/day) in winter 2016-2017 by more than three-fold. Moisture transport mainly attributed to "pineapple express" atmospheric rivers (ARs) in winter 2016-2017 suggests that the model falls short on a sub-seasonal scale, in which case storms from ARs contribute a significant portion of seasonal terrestrial precipitation. Further, we identify a potential mechanism for long-range SSS and precipitation teleconnections: standing Rossby waves. The heat applied to the atmosphere from anomalous tropical rainfall can generate standing Rossby waves that propagate to higher latitudes. SSS anomalies may be indicative of anomalous tropical rainfall, and by extension, standing Rossby waves that provide the long-range teleconnections.

  18. 2012/13 abnormal cold winter in Japan associated with Large-scale Atmospheric Circulation and Local Sea Surface Temperature over the Sea of Japan

    Science.gov (United States)

    Ando, Y.; Ogi, M.; Tachibana, Y.

    2013-12-01

    On Japan, wintertime cold wave has social, economic, psychological and political impacts because of the lack of atomic power stations in the era of post Fukushima world. The colder winter is the more electricity is needed. Wintertime weather of Japan and its prediction has come under the world spotlight. The winter of 2012/13 in Japan was abnormally cold, and such a cold winter has persisted for 3 years. Wintertime climate of Japan is governed by some dominant modes of the large-scale atmospheric circulations. Yasunaka and Hanawa (2008) demonstrated that the two dominant modes - Arctic Oscillation (AO) and Western Pacific (WP) pattern - account for about 65% of the interannual variation of the wintertime mean surface air temperature of Japan. A negative AO brings about cold winter in Japan. In addition, a negative WP also brings about cold winter in Japan. Looking back to the winter of 2012/13, both the negative AO and negative WP continued from October through December. If the previous studies were correct, it would have been extremely very cold from October through December. In fact, in December, in accordance with previous studies, it was colder than normal. Contrary to the expectation, in October and November, it was, however, warmer than normal. This discrepancy signifies that an additional hidden circumstance that heats Japan overwhelms these large-scale atmospheric circulations that cool Japan. In this study, we therefore seek an additional cause of wintertime climate of Japan particularly focusing 2012 as well as the AO and WP. We found that anomalously warm oceanic temperature surrounding Japan overwhelmed influences of the AO or WP. Unlike the inland climate, the island climate can be strongly influenced by surrounding ocean temperature, suggesting that large-scale atmospheric patterns alone do not determine the climate of islands. (a) Time series of a 5-day running mean AO index (blue) as defined by Ogi et al., (2004), who called it the SVNAM index. For

  19. Brazil The Duck Lagoon

    Science.gov (United States)

    2002-01-01

    This Multi-angle Imaging SpectroRadiometer (MISR) image of Brazil covers an area of about 298 kilometers x 358 kilometers, and was captured by the instrument's vertical-viewing (nadir) camera on December 27, 2001. The 'Lagoa dos Patos', in the Brazilian state of Rio Grande do Sul, translates to 'the Duck Lagoon'. It was named by 16th century Jesuit settlers, who asked the King of Spain to grant them title to the lagoon so that they could breed ducks. The King consented, but revoked his edict when he discovered that the 'duck-pond' (measuring about 14,000 square kilometers) was one of the largest lagoonal systems in the world. Note the sediment plume emanating from the southern end of the lagoon. Sailors in the 16th century imagined this outlet to be the mouth of a large river. Early Portuguese explorers mistook the entrance to the lagoon for the mouth of a great river and called it the Rio Grande. A series of wave-like points and curls form 'cusps' on the inner shores of the lagoon. The lagoon's characteristics change with short-term tide-induced cyclic perturbations, and with longer term large scale meteorological conditions. The distinctive wavelike 'cusps' along the inner shores result from the circulation, erosion and accumulation of sediments driven by wind and tidal action. The El Nino Southern Oscillation (ENSO) circulation affects precipitation amount and continental runoff, thereby changing the contents of the lagoon waters. High rainfall and increased freshwater discharge during El Nino events correspond with elevated dissolved nutrient concentrations and increased phytoplankton growth. La Nina years are dry and the associated low rainfall reduces the freshwater recharge to the lagoon, causing an increase in salinity. Occasional blooms of toxic cyanobacteria (Microcystis aeruginosa), have been registered in the lagoon when nutrient concentrations are elevated. A number of reeds and grasses are important to the lagoon estuary, including widgeon grass

  20. Deep winter convection and phytoplankton dynamics in the NW Mediterranean Sea under present climate and future (horizon 2030) scenarios.

    Science.gov (United States)

    Macias, Diego; Garcia-Gorriz, Elisa; Stips, Adolf

    2018-04-26

    Deep water convection (DC) in winter is one of the major processes driving open-ocean primary productivity in the Northwestern Mediterranean Sea. DC is highly variable in time, depending on the specific conditions (stratification, circulation and ocean-atmosphere interactions) of each specific winter. This variability also drives the interannual oscillations of open-ocean primary productivity in this important region for many commercially-important fish species. We use a coupled model system to 1) understand to what extent DC impacts phytoplankton seasonality in the present-day and 2) to explore potential changes in future scenarios (~2030). Our model represents quite accurately the present-day characteristics of DC and its importance for open-ocean phytoplankton blooms. However, for the future scenarios the importance of deep nutrients in fertilizing the euphotic layer of the NW Mediterranean decreases. The model simulates changes in surface density and on the levels of kinetic energy that make mesoscale activity associated with horizontal currents to become a more important fertilization mechanism, inducing subsequently phenological changes in seasonal plankton cycles. Because of our focus on the open-sea, an exact quantification of the impact of those changes on the overall biological production of the NW Mediterranean cannot be made at the moment.

  1. Ikaite crystal distribution in Arctic winter sea ice and implications for CO2 system dynamics

    DEFF Research Database (Denmark)

    Rysgaard, Søren; Søgaard, D. H.; Cooper, M.

    2012-01-01

    The precipitation of ikaite (CaCO3·6H2O) in polar sea ice is critical to the efficiency of the sea ice-driven carbon pump and potentially important to the global carbon cycle, yet the spatial and temporal occurrence of ikaite within the ice is poorly known. We report unique observations of ikaite...

  2. Ikaite crystal distribution in winter sea ice and implications for CO2 system dynamics

    DEFF Research Database (Denmark)

    Rysgaard, Søren; Søgaard, D.H.; Cooper, M.

    2013-01-01

    The precipitation of ikaite (CaCO3 ⋅ 6H2O) in polar sea ice is critical to the efficiency of the sea ice-driven carbon pump and potentially important to the global carbon cycle, yet the spatial and temporal occurrence of ikaite within the ice is poorly known. We report unique observations of ikai...

  3. Winter Counter-Wind Transport in the Inner Southwestern Yellow Sea

    Science.gov (United States)

    Wu, Hui; Gu, Jinghua; Zhu, Ping

    2018-01-01

    Coastal currents generally flow downshelf with land on the right side (Northern Hemisphere) under the geostrophic balance, and are often strengthened by downwelling-favorable winds. However, the recent mooring observation in the inner southwestern Yellow Sea showed that coastal transport direction can be substantially changed by tidal forcing. In the survey, the tidal-averaged transports at two out of three sites remained northward (i.e., in the upshelf direction) and opposite the downwelling-favorable northerly wind, except during a brief neap tide period. Numerical experiments showed that the incoming Poincaré wave tide from the East China Sea plays a key role in forming this counter-wind transport system. This tidal wave produces a shoreward tidal stress south of 33.5°N in the inner southwestern Yellow Sea, driving an upshelf transport under the Earth's rotation. Counterpropagating tidal waves from the East China Sea and the northern Yellow Sea collide in coastal water in 32.5-34°N, which produce a standing tidal wave and therefore a mean sea-surface setup with alongshore and cross-shelf scales of both >100 km. This sea-surface setup causes an alongshore sea surface gradient, which veers the upshelf transport to the offshore direction under geostrophic balance. The strong tidal current increases the tidal-mean bottom resistance in the SCW, thus reduces the wind-driven current to a magnitude smaller than the tide-induced residual transport velocity. Therefore, upshelf transport persists in the inner southwestern Yellow Sea, and the Changjiang River Estuary becomes a major source area for the inner southwestern Yellow Sea.

  4. Physical and biological characteristics of the winter-summer transition in the Central Red Sea

    KAUST Repository

    Zarokanellos, Nikolaos; Papadopoulos, Vassilis P.; Sofianos, Sarantis. S.; Jones, Burton

    2017-01-01

    of the CRS. Ship-based and glider observations in the CRS between March and June 2013 capture key features of the transition from winter to summer and depict the impact of the eddy activity on the EBC flow. Less saline and relatively warmer water of Indian

  5. Contrasting feeding strategies among wintering common eiders linked to white-tailed sea eagle predation

    DEFF Research Database (Denmark)

    Merkel, Flemming Ravn; Mosbech, Anders; Sonne, Christian

    Southwest Greenland is an international important wintering area for Greenland and Canadian common eiders (Somateria mollissima borealis). They distribute both in the shallow habitats along the outer coastline and in the fjords which are generally very deep. In the fjord systems, eiders are typic...

  6. Feeding habits of garfish, Belone belone euxini Günther, 1866 in autumn and winter in Turkey’s south–east coast of the Black Sea

    Directory of Open Access Journals (Sweden)

    Kaya, Ş.

    2017-02-01

    Full Text Available We studied the stomach content of Belone belone in the south–east Black Sea during autumn and winter months in 2010–2011. The most frequent feeding items in the diet were insects in autumn and fish in winter. Other items in the diet were mollusks, crustaceans and isopods. Flying ants were mostly consumed by male garfish, particularly the smaller fish, in autumn.

  7. Winter atmospheric circulation signature for the timing of the spring bloom of diatoms in the North Sea

    Science.gov (United States)

    Lohmann, Gerrit; Wiltshire, Karen

    2015-04-01

    Analysing long-term diatom data from the German Bight and observational climate data for the period 1962-2005, we found a close connection of the inter-annual variation of the timing of the spring bloom with the boreal winter atmospheric circulation. We examined the fact that high diatom counts of the spring bloom tended to occur later when the atmospheric circulation was characterized by winter blocking over Scandinavia. The associated pattern in the sea level pressure showed a pressure dipole with two centres located over the Azores and Norway and was tilted compared to the North Atlantic Oscillation. The bloom was earlier when the cyclonic circulation over Scandinavia allowed an increased inflow of Atlantic water into the North Sea which is associated with clearer, more marine water, and warmer conditions. The bloom was later when a more continental atmospheric flow from the east was detected. At Helgoland Roads, it seems that under turbid water conditions (= low light) zooplankton grazing can affect the timing of the phytoplankton bloom negatively. Warmer water temperatures will facilitate this. Under clear water conditions, light will be the main governing factor with regard to the timing of the spring bloom. These different water conditions are shown here to be mainly related to large-scale weather patterns. We found that the mean diatom bloom could be predicted from the sea level pressure one to three months in advance. Using historical pressure data, we derived a proxy for the timing of the spring bloom over the last centuries, showing an increased number of late (proxy-) blooms during the eighteenth century when the climate was considerably colder than today. We argue that these variations are important for the interpretation of inter-annual to centennial variations of biological processes. This is of particular interest when considering future scenarios, as well to considerations on past and future effects on the primary production and food webs.

  8. Phytoplankton pigment patterns and community composition in the northern South China Sea during winter

    Science.gov (United States)

    Zhai, Hongchang; Ning, Xiuren; Tang, Xuexi; Hao, Qiang; Le, Fengfeng; Qiao, Jing

    2011-03-01

    Phytoplankton pigment patterns and community composition were investigated in the northern South China Sea using high-performance liquid chromatography and the CHEMTAX software from February 11 to 23, 2009. We recognized four different vertical distribution patterns of pigments: chlorophyll a (Chi a)-like type, divinyl chlorophyll a (DV Chi a) type, even distribution type, and surface type. The average value of ratios of accessory photo-protective pigments (APP) to accessory photo-synthetic pigments was 0.89±0.63 in the upper 50 m and 0.16±0.06 below 50 m depth. With increasing depth, APP decreased and photo-synthetically active radiation was attenuated. There was an obvious succession in the phytoplankton community from inshore to the open sea. Diatoms were dominant in the inshore region, while pelagophytes, Prochlorococcus, cyanobacteria and prymnesiophytes were dominant in the open sea. The vertical distribution of phytoplankton also differed greatly from inshore to the open sea. In the coastal and shelf region, diatoms were important components in the whole water column. Cyanobacteria also had a high abundance at the Subsurface Chlorophyll a Maxima (SCM) in the shelf region. In the slope and open sea, Prochlorococcus and cyanobacteria were important groups above the SCM, while pelagophytes dominated below the SCM.

  9. Application of remotely piloted aircraft systems in observing the atmospheric boundary layer over Antarctic sea ice in winter

    Directory of Open Access Journals (Sweden)

    Marius O. Jonassen

    2015-10-01

    Full Text Available The main aim of this paper is to explore the potential of combining measurements from fixed- and rotary-wing remotely piloted aircraft systems (RPAS to complement data sets from radio soundings as well as ship and sea-ice-based instrumentation for atmospheric boundary layer (ABL profiling. This study represents a proof-of-concept of RPAS observations in the Antarctic sea-ice zone. We present first results from the RV Polarstern Antarctic winter expedition in the Weddell Sea in June–August 2013, during which three RPAS were operated to measure temperature, humidity and wind; a fixed-wing small unmanned meteorological observer (SUMO, a fixed-wing meteorological mini-aerial vehicle, and an advanced mission and operation research quadcopter. A total of 86 RPAS flights showed a strongly varying ABL structure ranging from slightly unstable temperature stratification near the surface to conditions with strong surface-based temperature inversions. The RPAS observations supplement the regular upper air soundings and standard meteorological measurements made during the campaign. The SUMO and quadcopter temperature profiles agree very well and, excluding cases with strong temperature inversions, 70% of the variance in the difference between the SUMO and quadcopter temperature profiles can be explained by natural, temporal, temperature fluctuations. Strong temperature inversions cause the largest differences, which are induced by SUMO's high climb rates and slow sensor response. Under such conditions, the quadcopter, with its slower climb rate and faster sensor, is very useful in obtaining accurate temperature profiles in the lowest 100 m above the sea ice.

  10. Dynamics of sea-ice biogeochemistry in the coastal Antarctica during transition from summer to winter

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S; Jena, B.; Mohan, R.

    The seasonality of carbon dioxide partial pressure (pCO2), air-sea CO2 fluxes and associated environmental parameters were investigated in the Antarctic coastal waters. The in-situ survey was carried out from the austral summer...

  11. Winter and summer monsoon water mass, heat and freshwater transport changes in the Arabian Sea near 8°N

    Science.gov (United States)

    Stramma, Lothar; Brandt, Peter; Schott, Friedrich; Quadfasel, Detlef; Fischer, Jürgen

    The differences in the water mass distributions and transports in the Arabian Sea between the summer monsoon of August 1993 and the winter monsoon of January 1998 are investigated, based on two hydrographic sections along approximately 8°N. At the western end the sections were closed by a northward leg towards the African continent at about 55°E. In the central basin along 8°N the monsoon anomalies of the temperature and density below the surface-mixed layer were dominated by annual Rossby waves propagating westward across the Arabian Sea. In the northwestern part of the basin the annual Rossby waves have much smaller impact, and the density anomalies observed there were mostly associated with the Socotra Gyre. Salinity and oxygen differences along the section reflect local processes such as the spreading of water masses originating in the Bay of Bengal, northward transport of Indian Central Water, or slightly stronger southward spreading of Red Sea Water in August than in January. The anomalous wind conditions of 1997/98 influenced only the upper 50-100 m with warmer surface waters in January 1998, and Bay of Bengal Water covered the surface layer of the section in the eastern Arabian Sea. Estimates of the overturning circulation of the Arabian Sea were carried out despite the fact that many uncertainties are involved. For both cruises a vertical overturning cell of about 4-6 Sv was determined, with inflow below 2500 m and outflow between about 300 and 2500 m. In the upper 300-450 m a seasonally reversing shallow meridional overturning cell appears to exist in which the Ekman transport is balanced by a geostrophic transport. The heat flux across 8°N is dominated by the Ekman transport, yielding about -0.6 PW for August 1993, and 0.24 PW for January 1998. These values are comparable to climatological and model derived heat flux estimates. Freshwater fluxes across 8°N also were computed, yielding northward freshwater fluxes of 0.07 Sv in January 1998 and 0

  12. Spatial genetic structure of Long-tailed Ducks (Clangula hyemalis) among Alaskan, Canadian, and Russian breeding populations

    Science.gov (United States)

    Wilson, Robert E.; Gust, J R; Petersen, Margaret; Talbot, Sandra L.

    2016-01-01

    Arctic ecosystems are changing at an unprecedented rate. How Arctic species are able to respond to such environmental change is partially dependent on the connections between local and broadly distributed populations. For species like the Long-tailed Duck (Clangula hyemalis), we have limited telemetry and band-recovery information from which to infer population structure and migratory connectivity; however, genetic analyses can offer additional insights. To examine population structure in the Long-tailed Duck, we characterized variation at mtDNA control region and microsatellite loci among four breeding areas in Alaska, Canada, and Russia. We observed significant differences in the variance of mtDNA haplotype frequencies between the Yukon-Kuskokwim Delta (YKD) and the three Arctic locations (Arctic Coastal Plain in Alaska, eastern Siberia, and central Canadian Arctic). However, like most sea duck genetic assessments, our study found no evidence of population structure based on autosomal microsatellite loci. Long-tailed Ducks use multiple wintering areas where pair formation occurs with some populations using both the Pacific and Atlantic Oceans. This situation provides a greater opportunity for admixture across breeding locales, which would likely homogenize the nuclear genome even in the presence of female philopatry. The observed mtDNA differentiation was largely due to the presence of two divergent clades: (A) a clade showing signs of admixture among all breeding locales and (B) a clade primarily composed of YKD samples. We hypothesize that the pattern of mtDNA differentiation reflects some degree of philopatry to the YKD and isolation of two refugial populations with subsequent expansion and admixture. We recommend additional genetic assessments throughout the circumpolar range of Long-tailed Ducks to further quantify aspects of genetic diversity and migratory connectivity in this species.

  13. Microplankton of the Barents Sea: current composition and structure on the eve of the winter

    Directory of Open Access Journals (Sweden)

    Makarevich P. R.

    2017-06-01

    Full Text Available The results of microplankton (Protista investigations in the Barents Sea (standard "Kola Meridian Transect", ~70–78° N, 33° 30′ E in November / December have been presented. Samples for the determination of the taxonomical composition and abundance have been fixed with buffered formalin and examined with light microscopy using Nageotte counting chambers. A list of species recorded in the Barents Sea on transect, abundance and vertical distribution of microplankton has been given: a the seasonal composition of species (Ceratium fusus, Dicroerisma psilonereiella, Dinophysis rotundata, Lessardia elongata aff., Oxytoxum caudatum, Pronoctiluca pelagica, Protoperidinium brevipes, Prorocentrum balticum (Dinophyta, Corethron criophilum (Bacillariophyta, Coccolithus pelagicus (Haptophyta, Halosphaera viridis (Prasinophyta; b mean values of the total biomass of microplankton and its distribution in the water column (1.14 mkg/l in the layer of 50–0 m, 0.97 mkg/l – 100–50 m, 0.75 mkg/l – 200–100 m, 0.53 mkg/l – 300–200 m. Such parameter as dominant species in the structure of the total number is less constant (the ordinary dominant O. caudatum, subdominants – L. elongata aff., P. balticum, C. pelagicus, C. criophilum; in some years, at selected sites of the Barents Sea most of the total number has been formed to unusual species (Emiliania huxleyi, Mesoporos perforatus. The less stable characteristics of microplancton are dominant species composition in the biomass structure, total number of cells and their distribution in the water column.

  14. Winter snow conditions on Arctic sea ice north of Svalbard during the Norwegian young sea ICE (N-ICE2015) expedition

    Science.gov (United States)

    Merkouriadi, Ioanna; Gallet, Jean-Charles; Graham, Robert M.; Liston, Glen E.; Polashenski, Chris; Rösel, Anja; Gerland, Sebastian

    2017-10-01

    Snow is a crucial component of the Arctic sea ice system. Its thickness and thermal properties control heat conduction and radiative fluxes across the ocean, ice, and atmosphere interfaces. Hence, observations of the evolution of snow depth, density, thermal conductivity, and stratigraphy are crucial for the development of detailed snow numerical models predicting energy transfer through the snow pack. Snow depth is also a major uncertainty in predicting ice thickness using remote sensing algorithms. Here we examine the winter spatial and temporal evolution of snow physical properties on first-year (FYI) and second-year ice (SYI) in the Atlantic sector of the Arctic Ocean, during the Norwegian young sea ICE (N-ICE2015) expedition (January to March 2015). During N-ICE2015, the snow pack consisted of faceted grains (47%), depth hoar (28%), and wind slab (13%), indicating very different snow stratigraphy compared to what was observed in the Pacific sector of the Arctic Ocean during the SHEBA campaign (1997-1998). Average snow bulk density was 345 kg m-3 and it varied with ice type. Snow depth was 41 ± 19 cm in January and 56 ± 17 cm in February, which is significantly greater than earlier suggestions for this region. The snow water equivalent was 14.5 ± 5.3 cm over first-year ice and 19 ± 5.4 cm over second-year ice.

  15. Community composition of picoeukaryotes in the South China Sea during winter

    Science.gov (United States)

    Lin, Yun-Chi; Chiang, Kuo-Ping; Kang, Lee-Kuo

    2017-07-01

    Picoeukaryotes, the smallest protists, are highly diverse and abundant in the ocean. However, little information is available about their community composition in the tropical northwestern Pacific Ocean. This study collected surface and deep chlorophyll maximum (DCM) waters from the South China Sea (SCS) to study the picoeukaryotic composition by constructing clone libraries of the 18S rRNA gene. The libraries were dominated by the heterotrophic organisms, alveolates and Rhizaria, which accounted for 46% and 16% of total clones, respectively. MALV-I was the most abundant group in alveolates, and Rhizaria appears to be a key organism in the SCS, particularly within DCM layers. These results indicate that parasitism is significant in the oligotrophic and tropical SCS. Apart from core-dinoflagellates, chlorophytes, haptophytes, cryptophytes and pelagophytes were other important contributors to primary production in pico-sized fraction based on quantitative and qualitative data.

  16. Effects of sea-ice and biogeochemical processes and storms on under-ice water fCO2 during the winter-spring transition in the high Arctic Ocean: Implications for sea-air CO2 fluxes

    Science.gov (United States)

    Fransson, Agneta; Chierici, Melissa; Skjelvan, Ingunn; Olsen, Are; Assmy, Philipp; Peterson, Algot K.; Spreen, Gunnar; Ward, Brian

    2017-07-01

    We performed measurements of carbon dioxide fugacity (fCO2) in the surface water under Arctic sea ice from January to June 2015 during the Norwegian young sea ICE (N-ICE2015) expedition. Over this period, the ship drifted with four different ice floes and covered the deep Nansen Basin, the slopes north of Svalbard, and the Yermak Plateau. This unique winter-to-spring data set includes the first winter-time under-ice water fCO2 observations in this region. The observed under-ice fCO2 ranged between 315 µatm in winter and 153 µatm in spring, hence was undersaturated relative to the atmospheric fCO2. Although the sea ice partly prevented direct CO2 exchange between ocean and atmosphere, frequently occurring leads and breakup of the ice sheet promoted sea-air CO2 fluxes. The CO2 sink varied between 0.3 and 86 mmol C m-2 d-1, depending strongly on the open-water fractions (OW) and storm events. The maximum sea-air CO2 fluxes occurred during storm events in February and June. In winter, the main drivers of the change in under-ice water fCO2 were dissolution of CaCO3 (ikaite) and vertical mixing. In June, in addition to these processes, primary production and sea-air CO2 fluxes were important. The cumulative loss due to CaCO3 dissolution of 0.7 mol C m-2 in the upper 10 m played a major role in sustaining the undersaturation of fCO2 during the entire study. The relative effects of the total fCO2 change due to CaCO3 dissolution was 38%, primary production 26%, vertical mixing 16%, sea-air CO2 fluxes 16%, and temperature and salinity insignificant.

  17. AK-Contaminant exposure and habitat use by declining species of sea ducks wintering near industrial developments on the Alaska Peninsula and Aleutian Islands

    Data.gov (United States)

    Department of the Interior — Declines of Steller’s eiders (Polysticta stelleri) (STEIs) have resulted in listing the North American breeding population as Threatened under the Endangered Species...

  18. Wave energy absorption by ducks

    OpenAIRE

    Kurniawan, Adi

    2017-01-01

    We study the absorption of wave energy by a single and multiple cam-shaped bodies referred to as ducks. Numerical models are developed under the assumptions of linear theory. We consider wave absorption by a single duck as well as by two lines of ducks meeting at an angle.

  19. Wave energy absorption by ducks

    DEFF Research Database (Denmark)

    Kurniawan, Adi

    2018-01-01

    We study the absorption of wave energy by a single and multiple cam-shaped bodies referred to as ducks. Numerical models are developed under the assumptions of linear theory. We consider wave absorption by a single duck as well as by two lines of ducks meeting at an angle....

  20. Effects of tides on the cross-isobath movement of the low-salinity plume in the western Yellow and East China Seas in winter

    Science.gov (United States)

    Wang, Bin; Hirose, Naoki; Yuan, Dongliang; Moon, Jae-Hong; Pan, Xishan

    2017-07-01

    Offshore extension of the fresh Subei coast water is identified in winter based on in site salinity observation data in this and previous studies. A high-resolution regional ocean circulation model is used to investigate the cross-isobath movement of low salinity-water over the Yellow and East China Seas, and it has reproduced the salinity distribution observed in the winter of 2014-2015 successfully. The model suggests that the low-salinity water is basically degenerated back to the eastern coast of China in winter because of strong northeasterly wind. However, a part of the low-salinity water extends offshore in the southeast direction across the 20-50 m isobaths over the Yangtze Bank, which cannot be explained by either the northerly winter monsoon or the Changjiang discharge. Numerical experiments suggest that the cross-isobath transport of the soluble substances is highly attributed to the tidal residual current, flowing southeastward across 20-50 m isobaths over the whole Yangtze Bank. The results of controlled experiments also indicate that the bottom shear of the tidal current, rather than the tidal mixing, plays a significant role in the cross-isobath current during winter.

  1. Nonbreeding duck use at Central Flyway National Wildlife Refuges

    Science.gov (United States)

    Andersson, Kent; Davis, Craig A.; Harris, Grant; Haukos, David A.

    2018-01-01

    Within the U.S. portion of the Central Flyway, the U.S. Fish and Wildlife Service manages waterfowl on numerous individual units (i.e., Refuges) within the National Wildlife Refuge System. Presently, the extent of waterfowl use that Refuges receive and the contribution of Refuges to waterfowl populations (i.e., the proportion of the Central Flyway population registered at each Refuge) remain unassessed. Such an evaluation would help determine to what extent Refuges support waterfowl relative to stated targets, aid in identifying species requiring management attention, inform management targets, and improve fiscal efficiencies. Using historic monitoring data (1954–2008), we performed this assessment for 23 Refuges in Texas, New Mexico, Oklahoma, Kansas, and Nebraska during migration and wintering months (October–March). We examined six dabbling ducks and two diving ducks, plus all dabbling ducks and all diving ducks across two periods (long-term [all data] and short-term [last 10 October–March periods]). Individual Refuge use was represented by the sum of monthly duck count averages for October–March. We used two indices of Refuge contribution: peak contribution and January contribution. Peak contribution was the highest monthly count average for each October–March period divided by the indexed population total for the Central Flyway in the corresponding year; January contribution used the January count average divided by the corresponding population index. Generally, Refuges in Kansas, Nebraska, and New Mexico recorded most use and contribution for mallards Anas platyrhynchos. Refuges along the Texas Gulf Coast recorded most use and contribution for other dabbling ducks, with Laguna Atascosa and Aransas (including Matagorda Island) recording most use for diving ducks. The long-term total January contribution of the assessed Refuges to ducks wintering in the Central Flyway was greatest for green-winged teal Anas creccawith 35%; 12–15% for American

  2. Punnett and duck genetics

    Indian Academy of Sciences (India)

    25, 191–194; reprinted in this issue as a J. Genet. classic, pages 3–7) ... 1932, starts with Punnett explaining that he started his work on ducks as he was asked ... text of Punnett's later comments on genes and human mental disease. Punnett's ...

  3. Effects of ACTH, capture, and short term confinement on glucocorticoid concentrations in harlequin ducks (Histrionicus histrionicus)

    Science.gov (United States)

    Nilsson, P.B.; Hollmén, Tuula E.; Atkinson, S.; Mashburn, K.L.; Tuomi, P.A.; Esler, Daniel N.; Mulcahy, D.M.; Rizzolo, D.J.

    2008-01-01

    Little is known about baseline concentrations of adrenal hormones and hormonal responses to stress in sea ducks, although significant population declines documented in several species suggest that sea ducks are exposed to increased levels of environmental stress. Such declines have been observed in geographically distinct harlequin duck populations. We performed an adrenocorticotropic hormone (ACTH) challenge to evaluate adrenal function and characterize corticosterone concentrations in captive harlequin ducks and investigated the effects of capture, surgery, and short term confinement on corticosterone concentrations in wild harlequin ducks. Harlequin ducks responded to the ACTH challenge with an average three-fold increase in serum corticosterone concentration approximately 90 min post injection, and a four- to five-fold increase in fecal glucocorticoid concentration 2 to 4 h post injection. Serum corticosterone concentrations in wild harlequin ducks increased within min of capture and elevated levels were found for several hours post capture, indicating that surgery and confinement maintain elevated corticosterone concentrations in this species. Mean corticosterone concentrations in wild harlequin ducks held in temporary captivity were similar to the maximum response levels during the ACTH challenge in captive birds. However, large variation among individuals was observed in responses of wild birds, and we found additional evidence suggesting that corticosterone responses varied between hatch year and after hatch year birds.

  4. Behavioral vs. molecular sources of conflict between nuclear and mitochondrial DNA: The role of male-biased dispersal in a Holarctic sea duck

    Science.gov (United States)

    Peters, Jeffrey L.; Bolender, Kimberly A.; Pearce, John M.

    2012-01-01

    Genetic studies of waterfowl (Anatidae) have observed the full spectrum of mitochondrial (mt) DNA population divergence, from apparent panmixia to deep, reciprocally monophyletic lineages. Yet, these studies often found weak or no nuclear (nu) DNA structure, which was often attributed to male-biased gene flow, a common behaviour within this family. An alternative explanation for this ‘conflict’ is that the smaller effective population size and faster sorting rate of mtDNA relative to nuDNA lead to different signals of population structure. We tested these alternatives by sequencing 12 nuDNA introns for a Holarctic pair of waterfowl subspecies, the European goosander (Mergus merganser merganser) and the North American common merganser (M. m. americanus), which exhibit strong population structure in mtDNA. We inferred effective population sizes, gene flow and divergence times from published mtDNA sequences and simulated expected differentiation for nuDNA based on those histories. Between Europe and North America, nuDNA ФST was 3.4-fold lower than mtDNA ФST, a result consistent with differences in sorting rates. However, despite geographically structured and monophyletic mtDNA lineages within continents, nuDNA ФST values were generally zero and significantly lower than predicted. This between- and within-continent contrast held when comparing mtDNA and nuDNA among published studies of ducks. Thus, male-mediated gene flow is a better explanation than slower sorting rates for limited nuDNA differentiation within continents, which is also supported by nonmolecular data. This study illustrates the value of quantitatively testing discrepancies between mtDNA and nuDNA to reject the null hypothesis that conflict simply reflects different sorting rates.

  5. Consequences of inhibition of mixed-layer deepening by the West India coastal current for winter phytoplankton bloom in the northeastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Vijith, V.; Vinayachandran, P.N.; Thushara, V.; Amol, P.; Shankar, D; Anil, A.C.

    Consequences of inhibition of mixed-layer deepening by the1 West India Coastal Current for winter phytoplankton bloom in2 the northeastern Arabian Sea3 V. Vijith1, P. N. Vinayachandran 1, V. Thushara 1, P. Amol 1, D. Shankar 2, A. C. Anil 24 1Centre... m in375 February (Figure 5h). As the ML deepens in the north, cold sub-surface water376 that is rich in NO3 and PO4 entrains to the ML (Figures 4a,d and e). Vertical sec-377 tions of the nutrients (Figure 4d-e) resemble the temperature sections...

  6. Increasing persistent haze in Beijing: potential impacts of weakening East Asian winter monsoons associated with northwestern Pacific sea surface temperature trends

    Directory of Open Access Journals (Sweden)

    L. Pei

    2018-03-01

    Full Text Available Over the past decades, Beijing, the capital city of China, has encountered increasingly frequent persistent haze events (PHE. While the increased pollutant emissions are considered as the most important reason, changes in regional atmospheric circulations associated with large-scale climate warming also play a role. In this study, we find a significant positive trend of PHE in Beijing for the winters from 1980 to 2016 based on updated daily observations. This trend is closely related to an increasing frequency of extreme anomalous southerly episodes in North China, a weakened East Asian trough in the mid-troposphere and a northward shift of the East Asian jet stream in the upper troposphere. These conditions together depict a weakened East Asian winter monsoon (EAWM system, which is then found to be associated with an anomalous warm, high-pressure system in the middle–lower troposphere over the northwestern Pacific. A practical EAWM index is defined as the seasonal meridional wind anomaly at 850 hPa in winter over North China. Over the period 1900–2016, this EAWM index is positively correlated with the sea surface temperature anomalies over the northwestern Pacific, which indicates a wavy positive trend, with an enhanced positive phase since the mid-1980s. Our results suggest an observation-based mechanism linking the increase in PHE in Beijing with large-scale climatic warming through changes in the typical regional atmospheric circulation.

  7. Abnormal storm waves in the winter East/Japan Sea: generation process and hindcasting using an atmosphere-wind wave modelling system

    Directory of Open Access Journals (Sweden)

    H. S. Lee

    2010-04-01

    Full Text Available Abnormal storm waves cause coastal disasters along the coasts of Korean Peninsula and Japan in the East/Japan Sea (EJS in winter, arising due to developed low pressures during the East Asia winter monsoon. The generation of these abnormal storm waves during rough sea states were studied and hindcast using an atmosphere-wave coupled modelling system. Wind waves and swell due to developed low pressures were found to be the main components of abnormal storm waves. The meteorological conditions that generate these waves are classified into three patterns based on past literature that describes historical events as well as on numerical modelling. In hindcasting the abnormal storm waves, a bogussing scheme originally designed to simulate a tropical storm in a mesoscale meteorological model was introduced into the modelling system to enhance the resolution of developed low pressures. The modelling results with a bogussing scheme showed improvements in terms of resolved low pressure, surface wind field, and wave characteristics obtained with the wind field as an input.

  8. On the differences between early and middle winter atmospheric responses to sea surface temperature anomalies in the northwest Atlantic

    International Nuclear Information System (INIS)

    Peng, S.; Mysak, L.A.; Derome, J.; Ritchie, H.; Dugas, B.

    1994-01-01

    Using an atmospheric global spectral model at RPN with T42 horizontal resolution, we have shown that the winter atmosphere in the mid-latitude is capable of reacting to the SST anomalies prescribed in the northwest Atlantic with two different responses. The nature of the response is determined by the climatological conditions of the winter system. Experiments are conducted using either the perpetual November or January conditions, with or without the SST anomalies prescribed. Six 50-day integrations, with positive (or negative) SST anomalies prescribed, initialized from independent November analyses and similarly, four runs initialized from January analyses, have been examined in comparison with their control runs

  9. Hydrography and biogeochemistry of the north western Bay of Bengal and the north eastern Arabian Sea during winter monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Balachandran, K.K.; Laluraj, C.M.; Jyothibabu, R.; Madhu, N.V.; Muraleedharan, K.R.; Vijay, J.G.; Maheswaran, P.A.; Ashraf, T.T.M.; Nair, K.K.C.; Achuthankutty, C.T.

    in the Arabian Sea is driven by net heat loss from the ocean, whereas the Bay of Bengal does not contribute to such large heat loss to the atmosphere. It appears that the subduction of high saline Arabian Sea water mass is the mechanism behind the formation of a...

  10. Quantifying changes and influences on mottled duck density in Texas

    Science.gov (United States)

    Ross, Beth; Haukos, David A.; Walther, Patrick

    2018-01-01

    Understanding the relative influence of environmental and intrinsic effects on populations is important for managing and conserving harvested species, especially those species inhabiting changing environments. Additionally, climate change can increase the uncertainty associated with management of species in these changing environments, making understanding factors affecting their populations even more important. Coastal ecosystems are particularly threatened by climate change; the combined effects of increasing severe weather events, sea level rise, and drought will likely have non-linear effects on coastal marsh wildlife species and their associated habitats. A species of conservation concern that persists in these coastal areas is the mottled duck (Anas fulvigula). Mottled ducks in the western Gulf Coast are approximately 50% below target abundance numbers established by the Gulf Coast Joint Venture for Texas and Louisiana, USA. Although evidence for declines in mottled duck abundance is apparent, specific causes of the decrease remain unknown. Our goals were to determine where the largest declines in mottled duck population were occurring along the system of Texas Gulf Coast National Wildlife Refuges and quantify the relative contribution of environmental and intrinsic effects on changes to relative population density. We modeled aerial survey data of mottled duck density along the Texas Gulf Coast from 1986–2015 to quantify effects of extreme weather events on an index to mottled duck density using the United States Climate Extremes Index and Palmer Drought Severity Index. Our results indicate that decreases in abundance are best described by an increase in days with extreme 1-day precipitation from June to November (hurricane season) and an increase in drought severity. Better understanding those portions of the life cycle affected by environmental conditions, and how to manage mottled duck habitat in conjunction with these events will likely be key to

  11. Diagnosing sea ice from the north american multi model ensemble and implications on mid-latitude winter climate

    Science.gov (United States)

    Elders, Akiko; Pegion, Kathy

    2017-12-01

    Arctic sea ice plays an important role in the climate system, moderating the exchange of energy and moisture between the ocean and the atmosphere. An emerging area of research investigates how changes, particularly declines, in sea ice extent (SIE) impact climate in regions local to and remote from the Arctic. Therefore, both observations and model estimates of sea ice become important. This study investigates the skill of sea ice predictions from models participating in the North American Multi-Model Ensemble (NMME) project. Three of the models in this project provide sea-ice predictions. The ensemble average of these models is used to determine seasonal climate impacts on surface air temperature (SAT) and sea level pressure (SLP) in remote regions such as the mid-latitudes. It is found that declines in fall SIE are associated with cold temperatures in the mid-latitudes and pressure patterns across the Arctic and mid-latitudes similar to the negative phase of the Arctic Oscillation (AO). These findings are consistent with other studies that have investigated the relationship between declines in SIE and mid-latitude weather and climate. In an attempt to include additional NMME models for sea-ice predictions, a proxy for SIE is used to estimate ice extent in the remaining models, using sea surface temperature (SST). It is found that SST is a reasonable proxy for SIE estimation when compared to model SIE forecasts and observations. The proxy sea-ice estimates also show similar relationships to mid-latitude temperature and pressure as the actual sea-ice predictions.

  12. Relating C-band Microwave and Optical Satellite Observations as A Function of Snow Thickness on First-Year Sea Ice during the Winter to Summer Transition

    Science.gov (United States)

    Zheng, J.; Yackel, J.

    2015-12-01

    The Arctic sea ice and its snow cover have a direct impact on both the Arctic and global climate system through their ability to moderate heat exchange across the ocean-sea ice-atmosphere (OSA) interface. Snow cover plays a key role in the OSA interface radiation and energy exchange, as it controls the growth and decay of first-year sea ice (FYI). However, meteoric accumulation and redistribution of snow on FYI is highly stochastic over space and time, which makes it poorly understood. Previous studies have estimated local-scale snow thickness distributions using in-situ technique and modelling but it is spatially limited and challenging due to logistic difficulties. Moreover, snow albedo is also critical for determining the surface energy balance of the OSA during the critical summer ablation season. Even then, due to persistent and widespread cloud cover in the Arctic at various spatio-temporal scales, it is difficult and unreliable to remotely measure albedo of snow cover on FYI in the optical spectrum. Previous studies demonstrate that only large-scale sea ice albedo was successfully estimated using optical-satellite sensors. However, space-borne microwave sensors, with their capability of all-weather and 24-hour imaging, can provide enhanced information about snow cover on FYI. Daily spaceborne C-band scatterometer data (ASCAT) and MODIS data are used to investigate the the seasonal co-evolution of the microwave backscatter coefficient and optical albedo as a function of snow thickness on smooth FYI. The research focuses on snow-covered FYI near Cambridge Bay, Nunavut (Fig.1) during the winter to advanced-melt period (April-June, 2014). The ACSAT time series (Fig.2) show distinct increase in scattering at melt onset indicating the first occurrence of melt water in the snow cover. The corresponding albedo exhibits no decrease at this stage. We show how the standard deviation of ASCAT backscatter on FYI during winter can be used as a proxy for surface roughness

  13. Lead poisoning in domestic ducks

    Energy Technology Data Exchange (ETDEWEB)

    Rac, R; Crisp, C S

    1954-05-01

    The death of wild ducks, due to the ingestion of lead shop, occurs frequently and is well documented. This paper discusses the death of domestic ducks due to the ingestion of lead. It describes the symptoms, and pathology of the lead poisoning of a clutch of 11 ducklings which were being raised on a farm in Australia. 3 references, 1 table.

  14. Myctophid and pelagic shrimp assemblages in the oxygen minimum zone of the Andaman Sea during the winter monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Karuppasamy, P.K.; LaluRaj, C.M.; Muraleedharan, K.R.; Nair, M.

    of myctophid in the oxygen minimum zone of Northern Arabian Sea. The Joint Global Ocean Flux23 study showed a strong relationship between the distribution of organisms and the oxygen profiles in the Arabian Sea, especially in locations where the OMZ..., M.S., Sardesai, S., Sarma, V.V.S.S., Shenoy, D.M., Nail, H, Maheswaran, P.A., Krishna Kumari, K., Rajesh, G., Sudhir, A.K. & Binu, M.S., Severe fish mortality associated with red tide observed in the sea off Cochin. Curr.Sci., (1998), 75, 543...

  15. Quantifying population-level risks using an individual-based model: sea otters, Harlequin Ducks, and the Exxon Valdez oil spill.

    Science.gov (United States)

    Harwell, Mark A; Gentile, John H; Parker, Keith R

    2012-07-01

    Ecological risk assessments need to advance beyond evaluating risks to individuals that are largely based on toxicity studies conducted on a few species under laboratory conditions, to assessing population-level risks to the environment, including considerations of variability and uncertainty. Two individual-based models (IBMs), recently developed to assess current risks to sea otters and seaducks in Prince William Sound more than 2 decades after the Exxon Valdez oil spill (EVOS), are used to explore population-level risks. In each case, the models had previously shown that there were essentially no remaining risks to individuals from polycyclic aromatic hydrocarbons (PAHs) derived from the EVOS. New sensitivity analyses are reported here in which hypothetical environmental exposures to PAHs were heuristically increased until assimilated doses reached toxicity reference values (TRVs) derived at the no-observed-adverse-effects and lowest-observed-adverse-effects levels (NOAEL and LOAEL, respectively). For the sea otters, this was accomplished by artificially increasing the number of sea otter pits that would intersect remaining patches of subsurface oil residues by orders of magnitude over actual estimated rates. Similarly, in the seaduck assessment, the PAH concentrations in the constituents of diet, sediments, and seawater were increased in proportion to their relative contributions to the assimilated doses by orders of magnitude over measured environmental concentrations, to reach the NOAEL and LOAEL thresholds. The stochastic IBMs simulated millions of individuals. From these outputs, frequency distributions were derived of assimilated doses for populations of 500,000 sea otters or seaducks in each of 7 or 8 classes, respectively. Doses to several selected quantiles were analyzed, ranging from the 1-in-1000th most-exposed individuals (99.9% quantile) to the median-exposed individuals (50% quantile). The resulting families of quantile curves provide the basis for

  16. MHC classⅠ gene in two duck lines

    Indian Academy of Sciences (India)

    Navya

    Weishan Ma duck (WS) is the eugenic endemic breed, one of the four famous ducks in China, as well Cherry Valley duck (CV) is the largest number of breeding variety. WS is egg strain and CV is meat type. The two duck lines mainly support the. Chinese waterfowl industry. In this study, MHC class Ⅰ genes of WS and CV ...

  17. Blood lead exposure concentrations in mottled ducks (Anas fulvigula) on the upper Texas coast

    Science.gov (United States)

    McDowell, Stephen K.; Conway, Warren C.; Haukos, David A.; Moon, Jena A.; Comer, Christopher E.; Hung, I-Kuai

    2015-01-01

    The mottled duck (Anas fulvigula) is a non-migratory waterfowl species dependent upon coastal marsh systems, including those on the Texas Chenier Plain National Wildlife Refuge (NWR) Complex, and considered a regional indicator species of marsh habitat quality. Research from the early 1970s, 1990s, and early-2000s indicated that mottled ducks continued to exhibit elevated wing-bone lead (Pb) concentrations, decades after implementation of non-toxic shot regulations. However, wing-bone concentrations reflect lifetime accumulation of Pb, whereas blood Pb concentrations reflect more recent exposure. To identify current potentially relevant temporal windows of Pb exposure, we collected 260 blood samples from mottled ducks during summer (n=124) and winter (n=136) from 2010–2012 on the Texas Chenier Plain NWR Complex. We quantified baseline blood Pb concentrations for all ages of mottled ducks, and hypothesized that blood lead concentrations would remain elevated above background levels (200 µg L–1) despite the 1983 and 1991 lead shot bans. Blood Pb concentrations ranged from below detection limits to >12,000 µg L–1, where >200 µg L–1 was associated with exposure levels above background concentrations. Male mottled ducks had the greatest blood Pb concentrations (30 times greater than females) with concentrations greater during winter than summer. Likewise, the proportion of exposed (>200 µg L–1) females increased from 14%–47% from summer to winter, respectively. Regardless of sex, adult mottled duck blood Pb concentrations were five times greater than juveniles, particularly during winter. We identified five plausible models that influenced blood Pb levels where year, site, and interactions among age*sex*season and between age*season were included in the top-ranked models. Frequency of exposure was greatest during winter, increasing from 12% in summer to 55% in winter, indicating that a temporal exposure window to environmental Pb exists between nesting

  18. Phylogenetic and pathogenic characterization of novel adenoviruses from long-tailed ducks (Clangula hyemalis)

    Science.gov (United States)

    Counihan, Katrina; Skerratt, Lee; Franson, J. Christian; Hollmen, Tuula E.

    2015-01-01

    Novel adenoviruses were isolated from a long-tailed duck (Clangula hyemalis) mortality event near Prudhoe Bay, Alaska in 2000. The long-tailed duck adenovirus genome was approximately 27 kb. A 907 bp hexon gene segment was used to design primers specific for the long-tailed duck adenovirus. Nineteen isolates were phylogenetically characterized based on portions of their hexon gene and 12 were most closely related to Goose adenovirus A. The remaining 7 shared no hexon sequences with any known adenoviruses. Experimental infections of mallards with a long-tailed duck reference adenovirus caused mild lymphoid infiltration of the intestine and paint brush hemorrhages of the mucosa and dilation of the intestine. This study shows novel adenoviruses from long-tailed ducks are diverse and provides further evidence that they should be considered in cases of morbidity and mortality in sea ducks. Conserved and specific primers have been developed that will help screen sea ducks for adenoviral infections.

  19. The diet of the South American sea lion (Otaria flavescens at Río Negro, Patagonia, Argentina, during the winter-spring period

    Directory of Open Access Journals (Sweden)

    Raimundo L. Bustos

    2012-12-01

    Full Text Available The South American sea lion, Otaria flavescens (Shaw, 1800 population is steadily expanding along the Patagonian coast of Argentina in the last decades. However, little is known about the feeding ecology of the species in the area. The aim of this study was to analyze the food habits of O. flavescens from 91 scats collected at Río Negro province, during the winter and spring of 2005. Fish occurred in 96% of scats containing prey remains, followed by cephalopods (26%. Raneya brasiliensis (Kaup, 1856 was the most frequent and abundant species occurring in 58.6% of samples and constituting almost 50% of fish predated. Second in importance were Porichthys porosissimus (Cuvier, 1829 and Cynoscion guatucupa (Cuvier, 1830 in terms of occurrence (%FO 20.7 and numbers (29.6% respectively. The squid Loligo gahi (d'Orbigny, 1835 was the most frequent cephalopod prey (42.1%, whereas Octopus tehuelchus (d'Orbigny, 1834 was the most abundant (77%. The higher amount and diversity of prey found in the spring in comparison with the winter season might be related to a higher feeding activity of seals or to a seasonal increase in food availability in the area.

  20. Duck viral enteritis in domestic muscovy ducks in Pennsylvania

    Science.gov (United States)

    Davison, S.; Converse, K.A.; Hamir, A.N.; Eckroade, R.J.

    1993-01-01

    Duck viral enteritis (DVE) outbreaks occurred at two different locations in Pennsylvania in 1991 and 1992. In the first outbreak, four ducks died out of a group of 30 domestic ducks; in the second outbreak, 65 ducks died out of a group of 114 domestic ducks, and 15 domestic geese died as well. A variety of species of ducks were present on both premises, but only muscovy ducks (Cairina moschata) died from the disease. On necropsy, gross lesions included hepatomegaly with petechial hemorrhages, petechial hemorrhages in the abdominal fat, petechial hemorrhages on the epicardial surface of the heart, and multifocal to coalescing areas of fibrinonecrotic material over the mucosal surface of the trachea, esophagus, intestine, and cloaca. Histologically, the liver had random multifocal areas of necrosis and eosinophilic intranuclear inclusion bodies in hepatocytes. DVE virus was isolated and identified using muscovy duck embryo fibroblast inoculation and virus neutralization. /// En dos sitios diferentes se presentaron brotes de enteritis viral de los patos en el estados de Pensilvania en los a??os 1991 y 1992. En el primer brote, cuatro de un lote de 30 patos murieron mientras que en el segundo brote murieron 65 patos de un lote de 114 patos y 15 gansos. En ambas localidades exist?-a una variedad de especies de patos, sin embargo, s??lamente los patos almizcleros (Cairina moschata) murieron. A la necropsia, las lesiones macrosc??picas incluyeron hepatomegalia con hemorragias petequiales, hemorragias petequiales en la grasa abdominal y en la superficie del epicardio, y ?!reas multifocales o coalescentes de material fibrinonecr??tico sobre la superficie de la mucosa de la tr?!quea, es??fago, intestino y cloaca. Histol??gicamente, el h?-gado mostraba ?!reas multifocales de necrosis y cuerpos de inclusi??n intranucleares eosinof?-licos en los hepatocitos. El virus de la enteritis viral de los patos fue aislado e identificado usando fibroblasto de embriones de pato almizclero

  1. Enhanced tropospheric BrO over Antarctic sea ice in mid winter observed by MAX-DOAS on board the research vessel Polarstern

    Directory of Open Access Journals (Sweden)

    T. Wagner

    2007-06-01

    Full Text Available We present Multi AXis-Differential Optical Absorption Spectroscopy (MAX-DOAS observations of tropospheric BrO carried out on board the German research vessel Polarstern during the Antarctic winter 2006. Polarstern entered the area of first year sea ice around Antarctica on 24 June 2006 and stayed within this area until 15 August 2006. For the period when the ship cruised inside the first year sea ice belt, enhanced BrO concentrations were almost continuously observed. Outside the first year sea ice belt, typically low BrO concentrations were found. Based on back trajectory calculations we find a positive correlation between the observed BrO differential slant column densities (ΔSCDs and the duration for which the air masses had been in contact with the sea ice surface prior to the measurement. While we can not completely rule out that in several cases the highest BrO concentrations might be located close to the ground, our observations indicate that the maximum BrO concentrations might typically exist in a (possibly extended layer around the upper edge of the boundary layer. Besides the effect of a decreasing pH of sea salt aerosol with altitude and therefore an increase of BrO with height, this finding might be also related to vertical mixing of air from the free troposphere with the boundary layer, probably caused by convection over the warm ocean surface at polynyas and cracks in the ice. Strong vertical gradients of BrO and O3 could also explain why we found enhanced BrO levels almost continuously for the observations within the sea ice. Based on our estimated BrO profiles we derive BrO mixing ratios of several ten ppt, which is slightly higher than many existing observations. Our observations indicate that enhanced BrO concentrations around Antarctica exist about one month earlier than observed by satellite instruments. From detailed radiative transfer simulations we find that MAX-DOAS observations are up to about one order of

  2. Interannual variations of net community production and air-sea CO2 flux from winter to spring in the western subarctic North Pacific

    International Nuclear Information System (INIS)

    Midorikawa, Takashi; Ogawa, Kan; Nemoto, Kazuhiro; Kamiya, Hitomi; Umeda, Takafumi; Hiraishi, Naotaka; Wada, Akira; Ishii, Masao

    2003-01-01

    The role of spring biological production for the air-sea CO 2 flux was quantified in the Western Subarctic Gyre (48 deg N, 165 deg E), where the vertical profile of temperature revealed the existence of a temperature minimum (Tmin) layer in the North Pacific. The vertical profiles of temperature, salinity, dissolved oxygen, nutrients and dissolved inorganic carbon, DIC, in the upper water column were significantly variable year by year in spring, 1996-2000. Correspondingly, surface seawater at this site in spring was supersaturated with CO 2 in 1997, 1999 and 2000, but was undersaturated in 1996 and 1998. The concentrations of DIC and nutrients in the winter mixed layer were estimated from those in the Tmin layer in spring with a correction for particle decomposition based on the apparent oxygen utilization. The net community production (NCP) and air-sea CO 2 flux from winter to spring were calculated from the vertically integrated deficits of DIC and nutrients in the upper water column between the two seasons. The calculation of the carbon budget indicated large interannual variations of NCP (0-13 mmol/m 2 /d) and CO 2 efflux (4-16 mmol/m 2 /d) for this period. The CO 2 efflux was generally low in the year when NCP was high. The close coupling between biological production and CO 2 efflux suggested the important role of the changes in the mixed-layer depth, as a key process controlling both processes, especially of the timing, so that a decrease in the mixed-layer depth could result in the activation of biological production. The early biological consumption of the surface DIC concentration could shorten the period for acting as a source for atmospheric CO 2 and depress the CO 2 efflux in the Western Subarctic Gyre from winter to spring in 1996 and 1998. On the contrary, in 1997, persistently deep vertical mixing until late spring could suppress the biological activity and give rise to long-lasting CO 2 efflux

  3. Sensitivity to ocean acidification parallels natural pCO2 gradients experienced by Arctic copepods under winter sea ice

    Science.gov (United States)

    Lewis, Ceri N.; Brown, Kristina A.; Edwards, Laura A.; Cooper, Glenn; Findlay, Helen S.

    2013-01-01

    The Arctic Ocean already experiences areas of low pH and high CO2, and it is expected to be most rapidly affected by future ocean acidification (OA). Copepods comprise the dominant Arctic zooplankton; hence, their responses to OA have important implications for Arctic ecosystems, yet there is little data on their current under-ice winter ecology on which to base future monitoring or make predictions about climate-induced change. Here, we report results from Arctic under-ice investigations of copepod natural distributions associated with late-winter carbonate chemistry environmental data and their response to manipulated pCO2 conditions (OA exposures). Our data reveal that species and life stage sensitivities to manipulated OA conditions were correlated with their vertical migration behavior and with their natural exposures to different pCO2 ranges. Vertically migrating adult Calanus spp. crossed a pCO2 range of >140 μatm daily and showed only minor responses to manipulated high CO2. Oithona similis, which remained in the surface waters and experienced a pCO2 range of <75 μatm, showed significantly reduced adult and nauplii survival in high CO2 experiments. These results support the relatively untested hypothesis that the natural range of pCO2 experienced by an organism determines its sensitivity to future OA and highlight that the globally important copepod species, Oithona spp., may be more sensitive to future high pCO2 conditions compared with the more widely studied larger copepods. PMID:24297880

  4. Quantifying the ocean, freshwater and human effects on year-to-year variability of one-sea-winter Atlantic salmon angled in multiple Norwegian rivers.

    Science.gov (United States)

    Otero, Jaime; Jensen, Arne J; L'Abée-Lund, Jan Henning; Stenseth, Nils Chr; Storvik, Geir O; Vøllestad, Leif Asbjørn

    2011-01-01

    Many Atlantic salmon, Salmo salar, populations are decreasing throughout the species' distributional range probably due to several factors acting in concert. A number of studies have documented the influence of freshwater and ocean conditions, climate variability and human impacts resulting from impoundment and aquaculture. However, most previous research has focused on analyzing single or only a few populations, and quantified isolated effects rather than handling multiple factors in conjunction. By using a multi-river mixed-effects model we estimated the effects of oceanic and river conditions, as well as human impacts, on year-to-year and between-river variability across 60 time series of recreational catch of one-sea-winter salmon (grilse) from Norwegian rivers over 29 years (1979-2007). Warm coastal temperatures at the time of smolt entrance into the sea and increased water discharge during upstream migration of mature fish were associated with higher rod catches of grilse. When hydropower stations were present in the course of the river systems the strength of the relationship with runoff was reduced. Catches of grilse in the river increased significantly following the reduction of the harvesting of this life-stage at sea. However, an average decreasing temporal trend was still detected and appeared to be stronger in the presence of salmon farms on the migration route of smolts in coastal/fjord areas. These results suggest that both ocean and freshwater conditions in conjunction with various human impacts contribute to shape interannual fluctuations and between-river variability of wild Atlantic salmon in Norwegian rivers. Current global change altering coastal temperature and water flow patterns might have implications for future grilse catches, moreover, positioning of aquaculture facilities as well as the implementation of hydropower schemes or other encroachments should be made with care when implementing management actions and searching for solutions to

  5. Quantifying the ocean, freshwater and human effects on year-to-year variability of one-sea-winter Atlantic salmon angled in multiple Norwegian rivers.

    Directory of Open Access Journals (Sweden)

    Jaime Otero

    Full Text Available Many Atlantic salmon, Salmo salar, populations are decreasing throughout the species' distributional range probably due to several factors acting in concert. A number of studies have documented the influence of freshwater and ocean conditions, climate variability and human impacts resulting from impoundment and aquaculture. However, most previous research has focused on analyzing single or only a few populations, and quantified isolated effects rather than handling multiple factors in conjunction. By using a multi-river mixed-effects model we estimated the effects of oceanic and river conditions, as well as human impacts, on year-to-year and between-river variability across 60 time series of recreational catch of one-sea-winter salmon (grilse from Norwegian rivers over 29 years (1979-2007. Warm coastal temperatures at the time of smolt entrance into the sea and increased water discharge during upstream migration of mature fish were associated with higher rod catches of grilse. When hydropower stations were present in the course of the river systems the strength of the relationship with runoff was reduced. Catches of grilse in the river increased significantly following the reduction of the harvesting of this life-stage at sea. However, an average decreasing temporal trend was still detected and appeared to be stronger in the presence of salmon farms on the migration route of smolts in coastal/fjord areas. These results suggest that both ocean and freshwater conditions in conjunction with various human impacts contribute to shape interannual fluctuations and between-river variability of wild Atlantic salmon in Norwegian rivers. Current global change altering coastal temperature and water flow patterns might have implications for future grilse catches, moreover, positioning of aquaculture facilities as well as the implementation of hydropower schemes or other encroachments should be made with care when implementing management actions and searching

  6. Harlequin duck (Histrionicus histrionicus) perspective: Harlequin duck population recovery following the Exxon Valdez oil spill: Progress, process, and constraints

    Science.gov (United States)

    Esler, Daniel N.; Bowman, Timothy D.; Trust, Kimberly A.; Ballachey, Brenda E.; Dean, Thomas A.; Jewett, Stephen C.; O'Clair, Charles E.; Holland-Bartels, Leslie E.

    2002-01-01

    Following the 1989 Exxon Valdez oil spill in Prince William Sound, Alaska, we studied the status of recovery of harlequin duck (Histrionicus histrionicus) populations during 1995-1998. We evaluated potential constraints to full recovery, including (1) exposure to residual oil, (2) food limitation, and (3) intrinsic demographic limitations on population growth rates. In this paper, we synthesize the findings from our work and incorporate information from other harlequin duck research and monitoring programs to provide a comprehensive evaluation of the response of this species to the Exxon Valdez oil spill. We conclude that harlequin duck populations had not fully recovered by 1998. Furthermore, adverse effects continued as many as 9 years after the oil spill, in contrast to the conventional paradigm that oil spill effects on bird populations are short-lived. These conclusions are based on the findings that (1) elevated cytochrome P450 induction on oiled areas indicated continued exposure to oil in 1998, (2) adult female winter survival was lower on oiled than unoiled areas during 1995-1998, (3) fall population surveys by the Alaska Department of Fish and Game indicated numerical declines in oiled areas during 1995-1997, and (4) densities on oiled areas in 1996 and 1997 were lower than expected using models that accounted for effects of habitat attributes. Based on hypothesized links between oil contamination and demography, we suggest that harlequin duck population recovery was constrained primarily by continued oil exposure. Full population recovery also will be delayed by the time necessary for intrinsic population growth to allow return to pre-spill numbers following cessation of residual oil spill effects. Although not all wildlife species were affected by the Exxon Valdez oil spill, and some others may have recovered quickly from any effects, harlequin duck life history characteristics and benthic, nearshore feeding habits make them susceptible to both initial

  7. Winter to spring variations of chromophoric dissolved organic matter in a temperate estuary (Po River, northern Adriatic Sea).

    Science.gov (United States)

    Berto, D; Giani, M; Savelli, F; Centanni, E; Ferrari, C R; Pavoni, B

    2010-07-01

    The light absorbing fraction of dissolved organic carbon (DOC), known as chromophoric dissolved organic matter (CDOM) showed wide seasonal variations in the temperate estuarine zone in front of the Po River mouth. DOC concentrations increased from winter through spring mainly as a seasonal response to increasing phytoplankton production and thermohaline stratification. The monthly dependence of the CDOM light absorption by salinity and chlorophyll a concentrations was explored. In 2003, neither DOC nor CDOM were linearly correlated with salinity, due to an exceptionally low Po river inflow. Though the CDOM absorbance coefficients showed a higher content of chromophoric dissolved organic matter in 2004 with respect to 2003, the spectroscopic features confirmed that the qualitative nature of CDOM was quite similar in both years. CDOM and DOC underwent a conservative mixing, only after relevant Po river freshets, and a change in optical features with an increase of the specific absorption coefficient was observed, suggesting a prevailing terrestrial origin of dissolved organic matter. Published by Elsevier Ltd.

  8. High-frequency and meso-scale winter sea-ice variability in the Southern Ocean in a high-resolution global ocean model

    Science.gov (United States)

    Stössel, Achim; von Storch, Jin-Song; Notz, Dirk; Haak, Helmuth; Gerdes, Rüdiger

    2018-03-01

    This study is on high-frequency temporal variability (HFV) and meso-scale spatial variability (MSV) of winter sea-ice drift in the Southern Ocean simulated with a global high-resolution (0.1°) sea ice-ocean model. Hourly model output is used to distinguish MSV characteristics via patterns of mean kinetic energy (MKE) and turbulent kinetic energy (TKE) of ice drift, surface currents, and wind stress, and HFV characteristics via time series of raw variables and correlations. We find that (1) along the ice edge, the MSV of ice drift coincides with that of surface currents, in particular such due to ocean eddies; (2) along the coast, the MKE of ice drift is substantially larger than its TKE and coincides with the MKE of wind stress; (3) in the interior of the ice pack, the TKE of ice drift is larger than its MKE, mostly following the TKE pattern of wind stress; (4) the HFV of ice drift is dominated by weather events, and, in the absence of tidal currents, locally and to a much smaller degree by inertial oscillations; (5) along the ice edge, the curl of the ice drift is highly correlated with that of surface currents, mostly reflecting the impact of ocean eddies. Where ocean eddies occur and the ice is relatively thin, ice velocity is characterized by enhanced relative vorticity, largely matching that of surface currents. Along the ice edge, ocean eddies produce distinct ice filaments, the realism of which is largely confirmed by high-resolution satellite passive-microwave data.

  9. Nonbreeding Duck Use and Management Contribution Trends for Central Flyway Refuges

    Science.gov (United States)

    Andersson, Kent; Davis, Craig A.; Harris, Grant; Haukos, David A.

    2018-01-01

    Within the U.S. portion of the Central Flyway, the U.S. Fish and Wildlife Service manages waterfowl on numerous individual units (i.e., Refuges) within the National Wildlife Refuge System. Presently, the extent of waterfowl use that Refuges receive and the contribution of Refuges to waterfowl populations (i.e., the proportion of the Central Flyway population registered at each Refuge) remain unassessed. Such an evaluation would help determine to what extent Refuges support waterfowl relative to stated targets, aid in identifying species requiring management attention, inform management targets, and improve fiscal efficiencies. Using historic monitoring data (1954–2008), we performed this assessment for 23 Refuges in Texas, New Mexico, Oklahoma, Kansas, and Nebraska during migration and wintering months (October–March). We examined six dabbling ducks and two diving ducks, plus all dabbling ducks and all diving ducks across two periods (long-term [all data] and short-term [last 10 October–March periods]). Individual Refuge use was represented by the sum of monthly duck count averages for October–March. We used two indices of Refuge contribution: peak contribution and January contribution. Peak contribution was the highest monthly count average for each October–March period divided by the indexed population total for the Central Flyway in the corresponding year; January contribution used the January count average divided by the corresponding population index. Generally, Refuges in Kansas, Nebraska, and New Mexico recorded most use and contribution for mallards Anas platyrhynchos. Refuges along the Texas Gulf Coast recorded most use and contribution for other dabbling ducks, with Laguna Atascosa and Aransas (including Matagorda Island) recording most use for diving ducks. The long-term total January contribution of the assessed Refuges to ducks wintering in the Central Flyway was greatest for green-winged teal Anas creccawith 35%; 12–15% for American

  10. Effect of age on the pathogenesis of duck tembusu virus in Cherry Valley ducks

    Science.gov (United States)

    Li, Ning; Lv, Chuanwei; Yue, Ruichao; Shi, Ying; Wei, Liangmeng; Chai, Tongjie; Liu, Sidang

    2015-01-01

    The effect of host age on the outcome of duck tembusu virus (DTMUV) infection was studied in ducks. Three groups of Cherry Valley ducks at 1, 3, and 7 weeks of age were intramuscularly infected with DTMUV to systematically observe the clinical symptoms, pathological changes, tissue viral loads, and immune responses. Severe clinical symptoms and neurological dysfunction were observed in 1-week-old ducks as early as 2 days post infection (dpi) and some died at 5–7 dpi. Three weeks-old ducks showed similar but milder symptoms and no deaths. However, 7-weeks-old ducks showed only transient loss of appetite. Gross lesions gradually reduced in severity as ducks matured. One-week-old ducks showed endocardial hemorrhage, splenomegaly, swelling in the lymph follicles of the ileum, liver, and kidney swelling with degeneration, and meningeal hyperemia. Three-weeks-old ducks showed only mild pathological lesions. No visible lesions were observed in 7-weeks-old ducks. However, pathological histology analysis demonstrated all infected ducks displayed viral encephalitis. DTMUV could be detected in the brains of 1-week-old ducks as early as 1 dpi and virus titers of most organs in 1-week-old ducks were significantly higher than that of 3- and 7-weeks-old ducks at 3–5 dpi. The patterns of IFN-γ, IL-2, and serum neutralizing antibodies were similar, and there were significant difference between the youngest ducks and the older ducks at early infection stage (P ducks were similar from 9 to 17 dpi, reduced clearance of virus was observed in the youngest groups comparing with the other two groups, indicating that immune system maturity was more important than the presence of neutralizing antibody. In summary, this study demonstrates that viral pathogenesis is strongest in 1-week-old ducks and the age-related immune response plays an important role in the pathogenesis of DTMUV in ducks. PMID:26106382

  11. Open-ocean convection process: A driver of the winter nutrient supply and the spring phytoplankton distribution in the Northwestern Mediterranean Sea

    Science.gov (United States)

    Severin, Tatiana; Kessouri, Faycal; Rembauville, Mathieu; Sánchez-Pérez, Elvia Denisse; Oriol, Louise; Caparros, Jocelyne; Pujo-Pay, Mireille; Ghiglione, Jean-François; D'Ortenzio, Fabrizio; Taillandier, Vincent; Mayot, Nicolas; Durrieu De Madron, Xavier; Ulses, Caroline; Estournel, Claude; Conan, Pascal

    2017-06-01

    This study was a part of the DeWEX project (Deep Water formation Experiment), designed to better understand the impact of dense water formation on the marine biogeochemical cycles. Here, nutrient and phytoplankton vertical and horizontal distributions were investigated during a deep open-ocean convection event and during the following spring bloom in the Northwestern Mediterranean Sea (NWM). In February 2013, the deep convection event established a surface nutrient gradient from the center of the deep convection patch to the surrounding mixed and stratified areas. In the center of the convection area, a slight but significant difference of nitrate, phosphate and silicate concentrations was observed possibly due to the different volume of deep waters included in the mixing or to the sediment resuspension occurring where the mixing reached the bottom. One of this process, or a combination of both, enriched the water column in silicate and phosphate, and altered significantly the stoichiometry in the center of the deep convection area. This alteration favored the local development of microphytoplankton in spring, while nanophytoplankton dominated neighboring locations where the convection reached the deep layer but not the bottom. This study shows that the convection process influences both winter nutrients distribution and spring phytoplankton distribution and community structure. Modifications of the convection's spatial scale and intensity (i.e., convective mixing depth) are likely to have strong consequences on phytoplankton community structure and distribution in the NWM, and thus on the marine food web.Plain Language SummaryThe deep open-ocean convection in the Northwestern Mediterranean Sea is an important process for the formation and the circulation of the deep waters of the entire Mediterranean Sea, but also for the local spring phytoplankton bloom. In this study, we showed that variations of the convective mixing depth induced different supply in nitrate

  12. Analysis of abietic acid and dehydroabietic acid residues in raw ducks and cooked ducks.

    Science.gov (United States)

    Zhu, Yongzhi; Zhang, Suzhen; Geng, Zhiming; Wang, Daoying; Liu, Fang; Zhang, Muhan; Bian, Huan; Xu, Weimin

    2014-10-01

    Rosin was once widely used for removal of duck feathers in China and is still being used secretly in some poultry processing enterprises. Abietic acid (AA) and dehydroabietic acid (DHAA) are the major compounds of rosin. In the present study, 90 duck samples were collected for investigation of AA and DHAA residues. Abietic acid and DHAA were simultaneously detected in 13 out 40 raw ducks, 8 out of 26 water-boiled salted ducks, and 7 out of 24 roasted ducks, respectively. In positive samples, averages of AA were significantly higher than those of DHAA in positive samples of the 3 types of ducks (P ducks were significantly higher than those in positive roasted ducks (P ducks were defeathered by means of rosin-containing defeathering agent, and cooking processes could reduce the AA and DHAA residues to some extent, but could not eliminate them completely. ©2014 Poultry Science Association Inc.

  13. Ringing and recovery data prove poor at detecting migratory short-stopping of diving ducks associated with climate change throughout Europe

    DEFF Research Database (Denmark)

    Tománková, Irena; Reid, Neil; Enlander, Ian

    2013-01-01

    Climate change has been shown to affect the distribution of many bird species. International Waterbird Census (IWC) data revealed that Tufted Duck Aythya fuligula and Goldeneye Bucephala clangula have shifted their European wintering distributions northeastwards as a direct response to increased ...... in recovery distances. We conclude that ringing and recovery data provide little utility in detecting changes in migratory behaviour of these waterbirds.......Climate change has been shown to affect the distribution of many bird species. International Waterbird Census (IWC) data revealed that Tufted Duck Aythya fuligula and Goldeneye Bucephala clangula have shifted their European wintering distributions northeastwards as a direct response to increased...... the southwest to northeast from 1950 onwards, but this change could not be linked to winter temperatures. Conversely, Tufted Duck directly violated our hypothesis with its recovery distances increasing significantly by about 400 km but again this change could not be explicitly linked to winter temperatures...

  14. Immune responses of ducks infected with duck Tembusu virus

    Directory of Open Access Journals (Sweden)

    Ning eLi

    2015-05-01

    Full Text Available Duck Tembusu virus (DTMUV can cause serious disease in ducks, characterized by reduced egg production. Although the virus has been isolated and detection methods developed, the host immune responses to DTMUV infection are unclear. Therefore, we systematically examined the expression of immune-related genes and the viral distribution in DTMUV-infected ducks, using quantitative real-time PCR. Our results show that DTMUV replicates quickly in many tissues early in infection, with the highest viral titers in the spleen 1 day after infection. Rig-1, Mda5, and Tlr3 are involved in the host immune response to DTMUV, and the expression of proinflammatory cytokines (Il-1β, -2, -6, Cxcl8 and antiviral proteins (Mx, Oas, etc. are also upregulated early in infection. The expression of Il-6 increased most significantly in the tissues tested. The upregulation of Mhc-I was observed in the brain and spleen, but the expression of Mhc-II was upregulated in the brain and downregulated in the spleen. The expression of the interferons was also upregulated to different degrees in the spleen but that of the brain was various. Our study suggests that DTMUV replicates rapidly in various tissues and that the host immune responses are activated early in infection. However, the overexpression of cytokines may damage the host. These results extend our understanding of the immune responses of ducks to DTMUV infection, and provide insight into the pathogenesis of DTMUV attributable to host factors.

  15. Effects of winter flooding on mass and gross energy of bottomland hardwood acorns

    Science.gov (United States)

    Alan G. Leach; Jacob N. Straub; Richard M. Kaminski; Andrew W. Ezell; Tracy S. Hawkins; Theodor D. Leininger

    2012-01-01

    Decomposition of red oak acorns (Quercus spp.; Section Erythrobalanus) could decrease forage biomass and gross energy (GE) available to wintering ducks from acorns. We estimated changes in mass and GE for 3 species of red oak acorns in flooded and non-flooded bottomland hardwood forests in Mississippi during winter 2009–2010. Mass...

  16. Lead and PCB's in canvasback ducks: Relationship between enzyme levels and residues in blood

    Science.gov (United States)

    Dieter, M.P.; Perry, M.C.; Mulhern, B.M.

    1976-01-01

    Blood samples were taken for two successive years from canvasback ducks trapped in the Chesapeake Bay. The first winter (1972?1973) five plasma enzymes known to respond to organochlorine poisoning were examined. Abnormal enzyme elevations suggested that 20% of the population sampled (23/115 ducks) might contain organochlorine contaminants, but no residue analyses were performed. The second winter (1974) two of the same enzymes, aspartate aminotransferase and lactate dehydrogenase, and a third enzyme known to be specifically inhibited by lead, delta-aminolevulinic acid dehydratase, were assayed in 95 blood samples. Blood residues of organochlorine compounds and of lead were determined in representative samples, and the correlations between residue levels and enzyme changes were examined. The enzyme bioassays in 1974 indicated that lead was a more prevalent environmental contaminant than organochlorine compounds in canvasback ducks; 17% of the blood samples had less than one-half of the normal delta-aminolevulinic acid dehydratase activity, but only 11% exhibited abnormal aspartate aminotransferase or lactate dehydrogenase activities. These findings were confirmed by residue analyses that demonstrated lead concentrations four times higher than background levels, but only relatively low organochlorine concentrations. There was a highly significant inverse correlation between delta-aminolevulinic acid dehydratase activity and blood lead concentrations (Pcontamination in waterfowl. In canvasback ducks 200 ppb of lead in the blood caused a 75% decrease in delta-aminolevulinic acid dehydratase activity, a magnitude of enzyme inhibition that disturbs heme synthesis and is regarded as detrimental in humans.

  17. Blood parasites of wood ducks

    Science.gov (United States)

    Herman, C.M.; Knisley, J.O.; Knipling, G.D.

    1971-01-01

    Examination of blood films from wood ducks (Aix sponsa) from several northeastern states revealed Haemoproteus, Leucocytozoon, Plasmodium and a typanosome. Haemoproteus occurred in all areas sampled and birds of the year from Massachusetts demonstrated the highest incidence during the last 2 weeks in August. Leucocytozoon was most prevalent in more northern areas. P. circumflexum and a trypanosome are reported for the first time from this host.

  18. Effect of age on the pathogenesis of Duck Tembusu virus in Cherry Valley ducks

    OpenAIRE

    Ning eLi; Chuanwei eLv; Ruichao eYue; Ying eShi; Sidang eLiu

    2015-01-01

    The effect of host age on the outcome of Duck Tembusu virus (DTMUV) infection was studied in ducks. Three groups of Cherry Valley ducks at 1, 3 and 7 weeks of age were intramuscularly infected with DTMUV to systematically observe the clinical symptoms, pathological changes, tissue viral loads and immune responses. Severe clinical symptoms and neurological dysfunction were observed in 1-week-old ducks as early as 2 day post infection (dpi) and some died at 5 –7 dpi. Three week old ducks showed...

  19. Effect of age on the pathogenesis of duck tembusu virus in Cherry Valley ducks

    OpenAIRE

    Li, Ning; Lv, Chuanwei; Yue, Ruichao; Shi, Ying; Wei, Liangmeng; Chai, Tongjie; Liu, Sidang

    2015-01-01

    The effect of host age on the outcome of duck tembusu virus (DTMUV) infection was studied in ducks. Three groups of Cherry Valley ducks at 1, 3, and 7 weeks of age were intramuscularly infected with DTMUV to systematically observe the clinical symptoms, pathological changes, tissue viral loads, and immune responses. Severe clinical symptoms and neurological dysfunction were observed in 1-week-old ducks as early as 2 days post infection (dpi) and some died at 5–7 dpi. Three weeks-old ducks sho...

  20. A cold pool south of Indo-Sri Lanka channel and its intrus on into the southeastern Arabian Sea during winter

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, R.R.; GirishKumar, M.S.; Ravichandran, M.; Gopalakrishna, V.V.; Pankajakshan, T.

    northwestward by the Maldives Island Chain. The resultant near-surface circulation also appears to strengthen the amplitude of the near-surface thermal inversions observed in the SouthEastern Arabian Sea (SEAS)...

  1. Cadmium and lead in tissues of Mallards (Anas platyrhynchos) and Wood Ducks (Aix sponsa) using the Illinois River (USA)

    International Nuclear Information System (INIS)

    Levengood, J.M.

    2003-01-01

    Tissue lead and cadmium concentrations were examined in two common, widely distributed species of duck, utilizing a major river system. - Cadmium and lead concentrations were determined in the tissues of Mallards and Wood Ducks collected from two waterfowl management areas along the Illinois River, USA, during the autumn and late winter of 1997-1998. Lead concentrations in livers of Mallards were lower than previously reported, and, along with those in a small sample of Wood Duck livers, were within background levels (<2.0 μg/g wet weight). Mean concentrations of cadmium in the kidneys of Wood Ducks utilizing the Illinois River were four times greater than in after-hatch-year Mallards, and 14 times greater than in hatch-year Mallards. Concentrations of cadmium in the kidneys of Wood Ducks were comparable with those of specimens dosed with cadmium or inhabiting contaminated areas in previous studies. Wood Ducks utilizing wetlands associated with the Illinois River, and presumably other portions of the lower Great Lakes region, may be chronically exposed to cadmium

  2. Effect of age on the pathogenesis of Duck Tembusu virus in Cherry Valley ducks

    Directory of Open Access Journals (Sweden)

    Ning eLi

    2015-06-01

    Full Text Available The effect of host age on the outcome of Duck Tembusu virus (DTMUV infection was studied in ducks. Three groups of Cherry Valley ducks at 1, 3 and 7 weeks of age were intramuscularly infected with DTMUV to systematically observe the clinical symptoms, pathological changes, tissue viral loads and immune responses. Severe clinical symptoms and neurological dysfunction were observed in 1-week-old ducks as early as 2 day post infection (dpi and some died at 5 –7 dpi. Three week old ducks showed similar but milder symptoms and no deaths. However, 7-week-old ducks showed only transient loss of appetite. Gross lesions gradually reduced in severity as ducks matured. One week old ducks showed endocardial haemorrhage, splenomegaly, swelling in the lymph follicles of the ileum, liver and kidney swelling with degeneration, and meningeal hyperemia. Three week old ducks showed only mild pathological lesions. No visible lesions were observed in 7-week-old ducks. However, pathological histology analysis demonstrated all infected ducks displayed viral encephalitis. DTMUV could be detected in the brains of 1-week-old ducks as early as 1 dpi and virus titers of most organs in 1-week-old ducks were significantly higher than that of 3- and 7-week-old ducks at 3 –5 dpi. The patterns of IFN-γ, IL-2, and serum neutralizing antibodies were similar, and there were significant difference between the youngest ducks and the older ducks at early infection stage (P<0.05. More important is that although the antibody titers of all infected ducks were similar from 9 dpi to 17 dpi, reduced clearance of virus was observed in the youngest groups comparing with the other two groups, indicating that immune system maturity was more important than the presence of neutralizing antibody. In summary, this study demonstrates that viral pathogenesis is strongest in 1-week-old ducks and the age-related immune response plays an important role in the pathogenesis of DTMUV in ducks.

  3. Feeding ecology of waterfowl wintering on evaporation ponds in California

    Science.gov (United States)

    Euliss, N.H.; Jarvis, R.L.; Gilmer, D.S.

    1991-01-01

    We examined the feeding ecology of Northern Pintails (Anas acuta), Northern Shovelers (A. clypeata), and Ruddy Ducks (Oxyura jamaicensis) wintering on drainwater evaporation ponds in California from 1982 through 1984. Pintails primarily consumed midges (Chironomidae) (39.3%) and widegeongrass (Ruppia maritima) nutlets (34.6%). Shovelers and Ruddy Ducks consumed 92.5% and 90.1% animal matter, respectively. Water boatmen (Corixidae) (51.6%), rotifers (Rotatoria) (20.4%), and copepods (Copepoda) (15.2%) were the most important Shoveler foods, and midges (49.7%) and water boatmen (36.0%) were the most important foods of Ruddy Ducks. All three species were opportunistic foragers, shifting their diets seasonally to the most abundant foods given their behavioral and morphological attributes.

  4. Blood parasites from California ducks and geese

    Science.gov (United States)

    Herman, C.M.

    1951-01-01

    Blood smears were procured from 1,011 geese and ducks of 19 species from various locations in California. Parasites were found in 28 individuals. The parasites observed included Haemoproteus hermani, Leucocytozoon simondi, microfilaria, Plasmodium relictum (=P. biziurae), and Plasmodium sp. with elongate gametocytes. This is the first report of a natural infection with a Plasmodium in North American wild ducks.

  5. Winter Wonderlands

    Science.gov (United States)

    Coy, Mary

    2011-01-01

    Listening to people complain about the hardships of winter and the dreariness of the nearly constant gray sky prompted the author to help her sixth graders recognize and appreciate the beauty that surrounds them for nearly five months of the year in western New York. The author opines that if students could see things more artistically, the winter…

  6. Duck plague: carrier state and gross pathology in black ducks

    Science.gov (United States)

    Ossa, Jorge E.

    1975-01-01

    Duck plague (UP) is a highly fatal disease of ducks, geese, and swans (family Anatidae), produced by a reticulo-endotheliotrophic virus classified as a member of the Herpesvirus group. The disease was recognized in Europe in 1949. On the American continent, the disease was first diagnosed in the United States in 1967. Very little is known of DP virus ecology, particularly of the mechanisms of interepizootic survival and movement. The tendency of the IIerpesviruses to enter into a quiescent state after an overt or inapparent infection is a proven characteristic for most of the members of this group. Herpes simplex, which is the model of the Herpesviruses, is said to be the classical example of a persistent recurrent viral infection. Burnet and Williams (4) were the first to recognize this kind of relationship between herpes simplex and its host in 1939. Later, it was found that the reactivation of the virus can be brought on by a variety of stimuli either physiological (menstruation), pathological (anaphylactic shock), chemical (pesticides) or physical (sunburn). This same latency property has been proved for every member of this group of viruses which has been studied adequately, DP is among the few Herpesviruses for which the carrier state has not been demonstrated, but there is circumstantial evidence suggesting it. The carrier state for DP seems to be a likely explanation for the persistence and the particular pattern of movement of this disease.

  7. PM 2.5 mass concentrations in comparison with aerosol optical depths over the Arabian Sea and Indian Ocean during winter monsoon

    Science.gov (United States)

    Ramachandran, S.

    An analysis of PM 2.5 mass concentrations and 0.5 μm aerosol optical depths (AODs) during the Northeast winter monsoon seasons of 1996-2000 is performed and intercompared. AODs are found to show diurnal variations over Coastal India (CI) (west coast) while they are relatively smooth over the Arabian Sea (AS) (5-20°N) and tropical Indian Ocean (TIO) (5°N-20°S). PM 2.5, PM 10 and total mass concentrations show less variations in a day over these oceanic regions. Columnar AODs are found to increase with an increase in the marine boundary layer aerosol concentrations over CI and AS while an opposite trend is seen over TIO. The yearly-mean AODs and mass concentrations are found to increase over CI and AS, over TIO the mass concentrations increased while the AODs decreased during 1996-2000. It is found from the 7-days air back trajectory analyses that at different altitudes air masses can originate from different source regions leading to changes in chemical, physical and optical characteristics of the aerosol between the surface and column. The differences in the surface and columnar measurements could also occur due to changes in the meteorological conditions, wind patterns, in addition to changes in production and subsequently the transport of aerosols. Least-squares fits to the above intercomparison resulted in intercepts of 0.24 and 0.22 over CI and AS indicating that the background AODs over these oceanic regions are higher. An examination of the daily-mean wind speeds and PM 2.5 mass concentrations yielded an index of wind dependence of 0.04 for AS and 0.07 for TIO. The background PM 2.5 mass concentrations are also found to be high at 36 and 25 μg m -3 over AS and TIO, respectively, indicating a stronger influence from the continent. Frequency distribution figures show that 28% of the PM 2.5 values over CI lie in the 60-80 μg m -3 range. Over AS the dominant mode of distribution is 40-60 μg m -3 with a peak value of 42%. Over TIO PM 2.5 values are found to

  8. Biogeochemical responses to late-winter storms in the Sargasso Sea, III—Estimates of export production using 234Th: 238U disequilibria and sediment traps

    Science.gov (United States)

    Maiti, Kanchan; Benitez-Nelson, Claudia R.; Lomas, Michael W.; Krause, Jeffrey W.

    2009-06-01

    Direct measurements of new production and carbon export in the subtropical North Atlantic Ocean appear to be too low when compared to geochemical-based estimates. It has been hypothesized that episodic inputs of new nutrients into surface water via the passage of mesoscale eddies or winter storms may resolve at least some of this discrepancy. Here, we investigated particulate organic carbon (POC), particulate organic nitrogen (PON), and biogenic silica (BSiO 2) export using a combination of water column 234Th: 238U disequilibria and free-floating sediment traps during and immediately following two weather systems encountered in February and March 2004. While these storms resulted in a 2-4-fold increase in mixed layer NO 3 inventories, total chlorophyll a and an increase in diatom biomass, the systems were dominated by generally low 234Th: 238U disequilibria, suggesting limited particle export. Several 234Th models were tested, with only those including non-steady state and vertical upwelling processes able to describe the observed 234Th activities. Although upwelling velocities were not measured directly in this study, the 234Th model suggests reasonable rates of 2.2-3.7 m d -1. Given the uncertainties associated with 234Th derived particle export rates and sediment traps, both were used to provide a range in sinking particle fluxes from the upper ocean during the study. 234Th particle fluxes were determined applying the more commonly used steady state, one-dimensional model with element/ 234Th ratios measured in sediment traps. Export fluxes at 200 m ranged from 1.91±0.20 to 4.92±1.22 mmol C m -2 d -1, 0.25±0.08 to 0.54±0.09 mmol N m -2 d -1, and 0.22±0.04 to 0.50±0.06 mmol Si m -2 d -1. POC export efficiencies (Primary Production/Export) were not significantly different from the annual average or from time periods without storms, although absolute POC fluxes were elevated by 1-11%. This increase was not sufficient, however, to resolve the discrepancy

  9. Experimental infection of duck origin virulent Newcastle disease virus strain in ducks.

    Science.gov (United States)

    Dai, Yabin; Cheng, Xu; Liu, Mei; Shen, Xinyue; Li, Jianmei; Yu, Shengqing; Zou, Jianmin; Ding, Chan

    2014-07-17

    Newcastle disease (ND) caused by virulent Newcastle disease virus (NDV) is an acute, highly contagious and fatal viral disease affecting most species of birds. Ducks are generally considered to be natural reservoirs or carriers of NDV while being resistant to NDV strains, even those most virulent for chickens; however, natural ND cases in ducks have been gradually increasing in recent years. In the present study, ducks of different breeds and ages were experimentally infected with duck origin virulent NDV strain duck/Jiangsu/JSD0812/2008 (JSD0812) by various routes to investigate the pathogenicity of NDV in ducks. Six breeds (mallard, Gaoyou, Shaoxing, Jinding, Shanma, and Pekin ducks) were infected intramuscularly (IM) with JSD0812 strain at the dose of 5 × 108 ELD50. Susceptibility to NDV infection among breeds varied, per morbidity and mortality. Mallard ducks were the most susceptible, and Pekin ducks the most resistant. Fifteen-, 30-, 45-, 60-, and 110-day-old Gaoyou ducks were infected with JSD0812 strain at the dose of 5 × 108 ELD50 either IM or intranasally (IN) and intraocularly (IO), and their disease development, viral shedding, and virus tissue distribution were determined. The susceptibility of ducks to NDV infection decreased with age. Most deaths occurred in 15- and 30-day-old ducklings infected IM. Ducks infected IN and IO sometimes exhibited clinical signs, but seldom died. Clinical signs were primarily neurologic. Infected ducks could excrete infectious virus from the pharynx and/or cloaca for a short period, which varied with bird age or inoculation route; the longest period was about 7 days. The rate of virus isolation in tissues from infected ducks was generally low, even in those from dead birds, and it appeared to be unrelated to bird age and infection route. The results confirmed that some of the naturally occurring NDV virulent strains can cause the disease in ducks, and that ducks play an important role in the epidemiology of ND. The

  10. Winter to winter recurrence of atmospheric circulation anomalies over East Asia and its impact on winter surface air temperature anomalies.

    Science.gov (United States)

    Zhao, Xia; Yang, Guang

    2017-01-01

    The persistence of atmospheric circulation anomalies over East Asia shows a winter to winter recurrence (WTWR) phenomenon. Seasonal variations in sea level pressure anomalies and surface wind anomalies display significantly different characteristics between WTWR and non-WTWR years. The WTWR years are characterized by the recurrence of both a strong (weak) anomalous Siberian High and an East Asian winter monsoon over two successive winters without persistence through the intervening summer. However, anomalies during the non-WTWR years have the opposite sign between the current and ensuing winters. The WTWR of circulation anomalies contributes to that of surface air temperature anomalies (SATAs), which is useful information for improving seasonal and interannual climate predictions over East Asia and China. In the positive (negative) WTWR years, SATAs are cooler (warmer) over East Asia in two successive winters, but the signs of the SATAs are opposite in the preceding and subsequent winters during the non-WTWR years.

  11. Optimization Technique in Scheduling Duck Tours

    OpenAIRE

    Norhazwani M. Y.; Khoo; C. F.; Hasrul Nisham R.

    2011-01-01

    Tourism industries are rapidly increased for the last few years especially in Malaysia. In order to attract more tourists, Malaysian Governance encourages any effort to increase Malaysian tourism industry. One of the efforts in attracting more tourists in Malacca, Malaysia is a duck tour. Duck tour is an amphibious sightseeing tour that works in two types of engines, hence, it required a huge cost to operate and maintain the vehicle. To other country, it is not so new but...

  12. Seasonal carcass composition and energy balance of female black ducks in Maine

    Science.gov (United States)

    Reinecke, K.J.; Stone, T.L.; Owen, R.B.

    1982-01-01

    Female Black Ducks (Anas rubripes) collected in Maine during the summer, fall, and winter of 1974-1976 showed significant seasonal variation in body weight, nonfat dry weight, gizzard and pectoral muscle weight, and fat, moisture, and protein content. Variation of body weight within and among seasons was correlated more strongly with carcass protein content, and with fat content during seasons of heavy lipid deposition, than with three structural size variables (culmen, tarsus, and sternum). Regression equations including fat and protein as independent variables accounted for 80-90% of the annual and seasonal variation in body weight; structural size variables alone accounted for less than 30%. Immature females averaged 54 and 99 g lighter, and carried 54 and 59 g less fat than adults during the fall and winter. Ducks of both age classes lost weight in December and January. Adult and immature females metabolized 59 and 64 g of fat and 17 and 25 g of protein in winter compared with 46 g of fat during the nesting season. Nutrient reserves are thus equally as important for the winter survival of these birds as for successfurl eproduction. Seasonal changes in carcass composition suggest that (1) fat deposited in late fall provides an energy reserve during winter, (2) a reduction in lean weight during winter may lower daily energy requirements and increase the effective amount of energy reserves, and (3) declining body weights during late winter may be an endogenous rhythm that reflects a shift in the expected benefits of an energy reserve compared to the costs of carrying additional weight,

  13. Studies on the quality of duck meat sausages during refrigeration

    OpenAIRE

    Naveen, Z.; Naik, B. R.; Subramanyam, B. V.; Reddy, P. M.

    2016-01-01

    Duck farming is on the raise in the current scenario, but processed products from duck meat are still uncommon to find. Investigating the duck meat qualities during storage will provide information to enhance duck meat utilization. Development of ready-to-eat and ready-to-cook duck meat products is expected to increase and improve non-chicken meat-based protein. The Study was aimed to evaluate the changes in quality characteristics of duck meat sausages preserved by refrigeration (7???1??C). ...

  14. Identification and synthetic modeling of factors affecting American black duck populations

    Science.gov (United States)

    Conroy, Michael J.; Miller, Mark W.; Hines, James E.

    2002-01-01

    We reviewed the literature on factors potentially affecting the population status of American black ducks (Anas rupribes). Our review suggests that there is some support for the influence of 4 major, continental-scope factors in limiting or regulating black duck populations: 1) loss in the quantity or quality of breeding habitats; 2) loss in the quantity or quality of wintering habitats; 3) harvest, and 4) interactions (competition, hybridization) with mallards (Anas platyrhychos) during the breeding and/or wintering periods. These factors were used as the basis of an annual life cycle model in which reproduction rates and survival rates were modeled as functions of the above factors, with parameters of the model describing the strength of these relationships. Variation in the model parameter values allows for consideration of scientific uncertainty as to the degree each of these factors may be contributing to declines in black duck populations, and thus allows for the investigation of the possible effects of management (e.g., habitat improvement, harvest reductions) under different assumptions. We then used available, historical data on black duck populations (abundance, annual reproduction rates, and survival rates) and possible driving factors (trends in breeding and wintering habitats, harvest rates, and abundance of mallards) to estimate model parameters. Our estimated reproduction submodel included parameters describing negative density feedback of black ducks, positive influence of breeding habitat, and negative influence of mallard densities; our survival submodel included terms for positive influence of winter habitat on reproduction rates, and negative influences of black duck density (i.e., compensation to harvest mortality). Individual models within each group (reproduction, survival) involved various combinations of these factors, and each was given an information theoretic weight for use in subsequent prediction. The reproduction model with highest

  15. Incidence of malaria in a wintering population of canvasbacks (Aythya valisineria) on Chesapeake Bay

    Science.gov (United States)

    Kocan, R.M.; Knisley, J.O.

    1970-01-01

    Canvasback ducks wintering on Chesapeake Bay had a 6% incidence of Leucocytozoon sirnondi and 2% incidence of Haemoproteus. Sub-inoculation of whole blood into Pekin ducklings produced a Plasmodium infection rate of 31%. Females were more frequently infected (12/22) than males (15/68). The parasite was identified as P. circumflexum.

  16. Selenium concentrations and enzyme activities of glutathione metabolism in wild long-tailed ducks and common eiders

    Science.gov (United States)

    Franson, J. Christian; Hoffman, David J.; Flint, Paul L.

    2011-01-01

    The relationships of selenium (Se) concentrations in whole blood with plasma activities of total glutathione peroxidase, Se-dependent glutathione peroxidase, and glutathione reductase were studied in long-tailed ducks (Clangula hyemalis) and common eiders (Somateria mollissima) sampled along the Beaufort Sea coast of Alaska, USA. Blood Se concentrations were >8 μg/g wet weight in both species. Linear regression revealed that the activities of total and Se-dependent glutathione peroxidase were significantly related to Se concentrations only in long-tailed ducks, raising the possibility that these birds were experiencing early oxidative stress.

  17. Characterization of duck (Anas platyrhynchos) MHC class Igene in ...

    Indian Academy of Sciences (India)

    LIN ZHANG

    2017-06-17

    Jun 17, 2017 ... from Weishan Ma duck and Cherry Valley duck were cloned, and their characterization were investigated. The overall ... Then the first-strand cDNAs were syn- thesized ... opment, Tokyo, Japan) and DNAMAN demo software.

  18. Space use of wintering waterbirds in India: Influence of trophic ecology on home-range size

    Science.gov (United States)

    Namgail, Tsewang; Takekawa, John Y.; Balachandran, Sivananinthaperumal; Sathiyaselvam, Ponnusamy; Mundkur, Taej; Newman, Scott H.

    2014-01-01

    Relationship between species' home range and their other biological traits remains poorly understood, especially in migratory birds due to the difficulty associated with tracking them. Advances in satellite telemetry and remote sensing techniques have proved instrumental in overcoming such challenges. We studied the space use of migratory ducks through satellite telemetry with an objective of understanding the influence of body mass and feeding habits on their home-range sizes. We marked 26 individuals, representing five species of migratory ducks, with satellite transmitters during two consecutive winters in three Indian states. We used kernel methods to estimate home ranges and core use areas of these waterfowl, and assessed the influence of body mass and feeding habits on home-range size. Feeding habits influenced the home-range size of the migratory ducks. Carnivorous ducks had the largest home ranges, herbivorous ducks the smallest, while omnivorous species had intermediate home-ranges. Body mass did not explain variation in home-range size. To our knowledge, this is the first study of its kind on migratory ducks, and it has important implications for their conservation and management.

  19. Vitamin A and contaminant concentrations in surf scoters (Melanitta perspicillata) wintering on the Pacific coast of British Columbia, Canada

    International Nuclear Information System (INIS)

    Harris, M.L.; Wilson, L.K.; Trudeau, S.F.; Elliott, J.E.

    2007-01-01

    Surf scoters are part of a community of sea ducks on the western coast of North America that have shown signs of long-term, unexplained declines in breeding bird numbers. Substantial numbers of scoters winter in the major harbours on the west coast, after breeding in the west-central northern boreal forest. To address the potential for contaminants to impact the health and survival of those birds, we investigated the condition and contamination of surf scoters during the winters of 1998-2001 at four foraging locations in the Strait of Georgia region of the Pacific coast of Canada. Vitamin A status was evaluated in liver and plasma samples collected from adults and juveniles, as part of a larger assessment of tissue contamination, body condition and biomarker responses. Individuals collected from a relatively contaminated site, Howe Sound, showed consistently low hepatic concentrations of retinol and retinyl palmitate forms of vitamin A, and gender-specific associations of retinyl palmitate with hepatic EROD activity. The relationship of hepatic retinol to retinyl palmitate was not constant across geographic locations, and a clear, linear relationship between the two forms of vitamin A was only evident in birds from the relatively uncontaminated site. This study also identified strong positive relationships between vitamin A and tissue burdens of cadmium and zinc. The positive association between hepatic retinyl palmitate and renal cadmium is similar to one observed in laboratory rats, in which a mechanism of interference with the controlled release of retinol from the liver was suggested

  20. Quantitative feed restriction of Pekin breeder ducks during the ...

    African Journals Online (AJOL)

    hatchability of incubated duck eggs owing to restricted feed intake. ... Egg numbers, infertile eggs, fertile eggs, dead embryos, and duck- lings hatched were recorded for each of the 12 pens. At the same time as the six male and 24 female ducks were ..... treatment but thereafter there was a drop, even lower than the.

  1. Do All Ducks Lay Eggs? The Generic Overgeneralization Effect

    Science.gov (United States)

    Leslie, Sarah-Jane; Khemlani, Sangeet; Glucksberg, Sam

    2011-01-01

    Generics are statements such as "tigers are striped" and "ducks lay eggs". They express general, though not universal or exceptionless, claims about kinds (Carlson & Pelletier, 1995). For example, the generic "ducks lay eggs" seems true even though many ducks (e.g. the males) do not lay eggs. The universally quantified version of the statement…

  2. WINTER SAECULUM

    Directory of Open Access Journals (Sweden)

    Emil Mihalina

    2017-03-01

    Full Text Available Accumulated imbalances in the economy and on the markets cause specific financial market dynamics that have formed characteristic patterns kept throughout long financial history. In 2008 Authors presented their expectations of key macroeconomic and selected asset class markets developments for period ahead based on Saeculum theory. Use of term Secular describes a specific valuation environment during prolonged period. If valuations as well as selected macro variables are considered as a tool for understanding business cycles then market cycles become much more obvious and easily understandable. Therefore over the long run, certain asset classes do better in terms of risk reward profile than others. Further on, there is no need for frequent portfolio rebalancing and timing of specific investment positions within a particular asset class market. Current stage in cycle development suggests a need for reassessment of trends and prevailing phenomena due to cyclical nture of long lasting Saeculums. Paper reviews developments in recognizable patterns of selected metrics in current Winter Saeculum dominated with prevailing forces of delivering, deflation and decrease in velocity of money.

  3. A 4-year study of avian influenza virus prevalence and subtype diversity in ducks of Newfoundland, Canada.

    Science.gov (United States)

    Huang, Yanyan; Wille, Michelle; Dobbin, Ashley; Robertson, Gregory J; Ryan, Pierre; Ojkic, Davor; Whitney, Hugh; Lang, Andrew S

    2013-10-01

    The island of Newfoundland, Canada, is at the eastern edge of North America and has migratory bird connections with the continental mainland as well as across the North Atlantic Ocean. Here, we report a 4-year avian influenza virus (AIV) epidemiological study in ducks in the St. John's region of Newfoundland. The overall prevalence of AIV detection in ducks during this study was 7.2%, with American Black Ducks contributing the vast majority of the collected samples and the AIV positives. The juvenile ducks showed a significantly higher AIV detection rate (10.6%) compared with adults (3.4%). Seasonally, AIV prevalence rates were higher in the autumn (8.4%), but positives were still detected in the winter (4.6%). Preliminary serology tests showed a high incidence of previous AIV infection (20/38, 52.6%). A total of 43 viruses were characterized for their HA-NA or HA subtypes, which revealed a large diversity of AIV subtypes and little recurrence of subtypes from year to year. Investigation of the movement patterns of ducks in this region showed that it is a largely non-migratory duck population, which may contribute to the observed pattern of high AIV subtype turnover. Phylogenetic analysis of 4 H1N1 and one H5N4 AIVs showed these viruses were highly similar to other low pathogenic AIV sequences from waterfowl in North America and assigned all gene segments into American-avian clades. Notably, the H1N1 viruses, which were identified in consecutive years, possessed homologous genomes. Such detection of homologous AIV genomes across years is rare, but indicates the role of the environmental reservoir in viral perpetuation.

  4. Seroprevalence of highly pathogenic avian influenza H5 subtype clade 2.3.2 on ducks and muscouvy ducks in small holders farm

    OpenAIRE

    Eny Martindah; Risa Indriani; S Wahyuwardani

    2015-01-01

    Seroprevalence studies of HPAI H5 subtype in ducks and muscouvy duck in smallholders farm was carried out in Serang and Tangerang District, Banten Province. The study comprised a serological survey to define the distribution and prevalence of HPAI H5 subtype infection on ducks and muscouvy ducks as well as attempted isolation of the virus from these species. Unit of sample in each stage was randomly choosen by multy stage random sample. Blood samples were taken from ducks and muscouvy ducks t...

  5. Oystercatcher Haematopus ostralegus winter mortality in The Netherlands : The effect of severe weather and food supply

    NARCIS (Netherlands)

    Camphuysen, CJ; Ens, B.J.; Heg, Dierik; Hulscher, JB; VanderMeer, J; Smit, CJ

    1996-01-01

    Wintering Oystercatchers in The Netherlands are concentrated in the Wadden Sea (c. 200 000), with substantial numbers in the Delta area (c. 90 000). Only 1% of the total wintering population is normally found along the North Sea coast. Cold-rushes under severe winter conditions lead to a reduction

  6. Measurement of Phenotype Characteristics of Sasak Ducks: Indian Runner Ducks of Lombok Island Indonesia

    OpenAIRE

    Mohammad Hasil Tamzil; Budi Indarsih

    2017-01-01

    This study was designed to determine the phenotype characteristics of Sasak ducks in Lombok Island. The study used 64 Sasak ducks at production stage which were kept intensively by small holder farmers. Observations on the characteristics of the feather color were carried out directly on each animal. The data observed were feather colors, beak color, and the color of the foot and shank, while the data on the size of the body that was observed were body weight, beak length, neck length, back ...

  7. Estuarine circulation reversals and related rapid changes in winter near-bottom oxygen conditions in the Gulf of Finland, Baltic Sea

    Directory of Open Access Journals (Sweden)

    T. Liblik

    2013-10-01

    Full Text Available The reversal of estuarine circulation caused by southwesterly wind forcing may lead to vanishing of stratification and subsequently to oxygenation of deep layers during the winter in the Gulf of Finland. Six conductivity, temperature, depth (CTD+oxygen transects (130 km long, 10 stations were conducted along the thalweg from the western boundary to the central gulf (21 December 2011–8 May 2012. Two bottom-mounted ADCP were installed, one near the western border and the second in the central gulf. A CTD with a dissolved oxygen sensor was deployed close to the western ADCP. Periods of typical estuarine circulation were characterized by strong stratification, high salinity, hypoxic conditions and inflow to the gulf in the near-bottom layer. Two circulation reversals were observed: one in December–January and one in February. The first reversal event was well developed; it caused the disappearance of the stratification and an increase in the oxygen concentration from hypoxic values to 270 μmol L−1 (to 6 mL L−1 throughout the water column along the thalweg and lasted approximately 1.5 months. Shifts from estuarine circulation to reversed circulation and vice versa were both associated with strong longitudinal (east–west gulf currents (up to 40 cm s−1 in the deep layer. The change from oxygenated to hypoxic conditions in the western near-entrance area of the gulf occurred very rapidly, within less than a day, due to the intrusion of the hypoxic salt wedge from the NE Baltic Proper. In the eastern part of the gulf, good oxygen conditions caused by reversals remained for a few months.

  8. Behavioural adjustment in response to increased predation risk: a study in three duck species.

    Directory of Open Access Journals (Sweden)

    Cédric Zimmer

    Full Text Available Predation directly triggers behavioural decisions designed to increase immediate survival. However, these behavioural modifications can have long term costs. There is therefore a trade-off between antipredator behaviours and other activities. This trade-off is generally considered between vigilance and only one other behaviour, thus neglecting potential compensations. In this study, we considered the effect of an increase in predation risk on the diurnal time-budget of three captive duck species during the wintering period. We artificially increased predation risk by disturbing two groups of 14 mallard and teals at different frequencies, and one group of 14 tufted ducks with a radio-controlled stressor. We recorded foraging, vigilance, preening and sleeping durations the week before, during and after disturbance sessions. Disturbed groups were compared to an undisturbed control group. We showed that in all three species, the increase in predation risk resulted in a decrease in foraging and preening and led to an increase in sleeping. It is worth noting that contrary to common observations, vigilance did not increase. However, ducks are known to be vigilant while sleeping. This complex behavioural adjustment therefore seems to be optimal as it may allow ducks to reduce their predation risk. Our results highlight the fact that it is necessary to encompass the whole individual time-budget when studying behavioural modifications under predation risk. Finally, we propose that studies of behavioural time-budget changes under predation risk should be included in the more general framework of the starvation-predation risk trade-off.

  9. The response of ducks to V4 Newcastle disease virus and its transmission to contact ducks and domestic chickens

    Directory of Open Access Journals (Sweden)

    Majid Bouzari

    2014-06-01

    Full Text Available Experimental infection of Muscovy ducks with V4 strain of Newcastle disease virus was undertaken to determine the response of the ducks to the virus and the possibility of virus transmission to ducks and chickens in village like conditions. Twelve ducks were randomly and equally divided into three groups of control, inoculated and in-contact. Additionally, the chickens were placed into two groups of four animals each, namely in-contact and control. The inoculated and in-contact ducks and in-contact chickens were kept together. The eye drop route was used for inoculation and hemagglutination inhibition (HI antibodies were measured for assessment of antibody response and cloacal and pharyngeal swabs were used for detection of the virus. The primary antibody response of inoculated ducks was very high and rapid (geometric mean titers [Log base 2] of up to 5.75 ± 0.50. The in-contact ducks showed antibody response with the same pattern but lower titers than the inoculated ducks (geometric mean titers [Log base 2] of up to 3.25 ± 1.70. The in-contact chickens showed a slight increase of HI antibody (geometric mean titers [Log base 2] of up to 2.25 ± 1.25 while the control chickens did not show any increase. The antibody response indicated the transmission of the virus to contact ducks and chickens. A single isolation of virus confirmed the ability of ducks to excrete the virus. It was concluded that the V4 strain of Newcastle disease virus was highly antigenic for ducks, and ducks can transmit it to other ducks and also in-contact chickens.

  10. Potential effects of drought on carrying capacity for wintering waterfowl in the Central Valley of California

    Science.gov (United States)

    Petrie, Mark J.; Fleskes, Joseph P.; Wolder, Mike A.; Isola, Craig R.; Yarris, Gregory S.; Skalos, Daniel A.

    2016-01-01

    We used the bioenergetics model TRUEMET to evaluate potential effects of California's recent drought on food supplies for waterfowl wintering in the Central Valley under a range of habitat and waterfowl population scenarios. In nondrought years in the current Central Valley landscape, food supplies are projected to be adequate for waterfowl from fall through early spring (except late March) even if waterfowl populations reach North American Waterfowl Management Plan goals. However, in all drought scenarios that we evaluated, food supplies were projected to be exhausted for ducks by mid- to late winter and by late winter or early spring for geese. For ducks, these results were strongly related to projected declines in winter-flooded rice fields that provide 45% of all the food energy available to ducks in the Central Valley in nondrought water years. Delayed flooding of some managed wetlands may help alleviate food shortages by providing wetland food resources better timed with waterfowl migration and abundance patterns in the Central Valley, as well as reducing the amount of water needed to manage these habitats. However, future research is needed to evaluate the impacts of delayed flooding on waterfowl hunting, and whether California's existing water delivery system would make delayed flooding feasible. Securing adequate water supplies for waterfowl and other wetland-dependent birds is among the greatest challenges facing resource managers in coming years, especially in the increasingly arid western United States.

  11. Efficient Strategy to Generate a Vectored Duck Enteritis Virus Delivering Envelope of Duck Tembusu Virus

    Directory of Open Access Journals (Sweden)

    Zhong Zou

    2014-06-01

    Full Text Available Duck Tembusu virus (DTMUV is a recently emerging pathogenic flavivirus that has resulted in a huge economic loss in the duck industry. However, no vaccine is currently available to control this pathogen. Consequently, a practical strategy to construct a vaccine against this pathogen should be determined. In this study, duck enteritis virus (DEV was examined as a candidate vaccine vector to deliver the envelope (E of DTMUV. A modified mini-F vector was inserted into the SORF3 and US2 gene junctions of the attenuated DEV vaccine strain C-KCE genome to generate an infectious bacterial artificial chromosome (BAC of C-KCE (vBAC-C-KCE. The envelope (E gene of DTMUV was inserted into the C-KCE genome through the mating-assisted genetically integrated cloning (MAGIC strategy, resulting in the recombinant vector, pBAC-C-KCE-E. A bivalent vaccine C-KCE-E was generated by eliminating the BAC backbone. Immunofluorescence and western blot analysis results indicated that the E proteins were vigorously expressed in C-KCE-E-infected chicken embryo fibroblasts (CEFs. Duck experiments demonstrated that the insertion of the E gene did not alter the protective efficacy of C-KCE. Moreover, C-KCE-E-immunized ducks induced neutralization antibodies against DTMUV. These results demonstrated, for the first time, that recombinant C-KCE-E can serve as a potential bivalent vaccine against DEV and DTMUV.

  12. A multiplex PCR for detection of six viruses in ducks.

    Science.gov (United States)

    Wang, Yongjuan; Zhu, Shanyuan; Hong, Weiming; Wang, Anping; Zuo, Weiyong

    2017-10-01

    In this study, six pairs of specific primers that can amplify DNA fragments of different sizes were designed and synthesized according to viral protein gene sequences published in GenBank. Then, a multiplex PCR method was established for rapid detection of duck hepatitis virus 1, duck plague virus, duck Tembusu virus, muscovy duck parvovirus, muscovy duck reovirus, and duck H9N2 avian influenza virus, and achieve simple and rapid detection of viral diseases in ducks. Single PCR was used to confirm primer specificity, and PCR conditions were optimized to construct a multiplex PCR system. Specificity and sensitivity assays were also developed. The multiplex PCR was used to detect duck embryos infected with mixed viruses and those with clinically suspected diseases to verify the feasibility of the multiplex PCR. Results show that the primers can specifically amplify target fragments, without any cross-amplification with other viruses. The multiplex PCR system can amplify six DNA fragments from the pooled viral genomes and specifically detect nucleic acids of the six duck susceptible viruses when the template amount is 10 2 copies/μl. In addition, the system can be used to detect viral nucleic acids in duck embryos infected with the six common viruses. The detection results for clinical samples are consistent with those detected by single PCR. Therefore, the established multiplex PCR method can perform specific, sensitive, and high-throughput detection of six duck-infecting viruses and can be applied to clinical identification and diagnosis of viral infection in ducks. Copyright © 2017. Published by Elsevier B.V.

  13. Irradiation preservation study on Beijing roast duck by low dose

    Energy Technology Data Exchange (ETDEWEB)

    Weiguo, Wang; Yongbao, Gu; Fengmei, Li [Beijing Normal Univ., BJ (China). Inst. of Low Energy Nuclear Physics; and others

    1989-02-01

    The irradiation technique combined with freezing has been used to control the microorganism in Beijing Roast Duck. Cobal-60 was chosen as {gamma}-ray source. The absorbed dose was 2 kGy on an average. After irrdiation, the microbe counts have reached the tolerable. Compared with untreated ducks, the irradiated ones showed no remarkable change in nutrition, chemistry, vitamin etc. It has been proved through test that the irradiated frozen Beijing Roast Duck is wholesome.

  14. Irradiation preservation study on Beijing roast duck by low dose

    International Nuclear Information System (INIS)

    Wang Weiguo; Gu Yongbao; Li Fengmei

    1989-01-01

    The irradiation technique combined with freezing has been used to control the microorganism in Beijing Roast Duck. Cobal-60 was chosen as γ-ray source. The absorbed dose was 2 kGy on an average. After irrdiation, the microbe counts have reached the tolerable. Compared with untreated ducks, the irradiated ones showed no remarkable change in nutrition, chemistry, vitamin etc. It has been proved through test that the irradiated frozen Beijing Roast Duck is wholesome

  15. Egg Production Potentials of Muscovy Ducks ( Cairina moschata ...

    African Journals Online (AJOL)

    Ducks in intensive management systems came into lay significantly (P<0.05) earlier, (IO, 203 days and IW, 207 days) than ducks in semi-intensive management system (248 days). Eggs from ducks in IO and IW were significantly (P<0.05) heavier (76.35 and 76.27g, respectively) than eggs from those in SI. Clutch sizes were ...

  16. Duck "beak atrophy and dwarfism syndrome" disease complex: Interplay of novel goose parvovirus-related virus and duck circovirus?

    Science.gov (United States)

    Li, P; Li, J; Zhang, R; Chen, J; Wang, W; Lan, J; Xie, Z; Jiang, S

    2018-04-01

    As a newly emerged infectious disease, duck "beak atrophy and dwarfism syndrome (BADS)" disease has caused huge economic losses to waterfowl industry in China since 2015. Novel goose parvovirus-related virus (NGPV) is believed the main pathogen of BADS disease; however, BADS is rarely reproduced by infecting ducks with NGPV alone. As avian circovirus infection causes clinical symptoms similar to BADS, duck circovirus (DuCV) is suspected the minor pathogen of BADS disease. In this study, an investigation was carried out to determine the coinfection of NGPV and DuCV in duck embryos and in ducks with BADS disease. According to our study, the coinfection of emerging NGPV and DuCV was prevalent in East China (Shandong, Jiangsu and Anhui province) and could be vertical transmitted, indicating their cooperative roles in duck BADS disease. © 2018 Blackwell Verlag GmbH.

  17. A comparative study on radiosensitivity of neonatal ducks and chickens

    International Nuclear Information System (INIS)

    Nakanishi, Y.H.; Ogata, Kenji; Sugimura, Makoto

    1979-01-01

    Neonatal ducks and chickens are exposed to a wholebody X-irradiation ranging from 100 R to 3,000 R at a dose-rate of 185 R per min. Lethal doses to 50% in 30 days are estimated to be 500 R for the ducks, while 800 R for the chickens. The ducks appear to be much more radiosensitive than the chickens. Histopathological observations of various organs of the exposed specimens after death reveal remarkable alterations: Particularly lymphoid organs are affected much more in the ducks than in the chickens at lesser doses than 1,000 R. (author)

  18. Comparative study on radiosensitivity of neonatal ducks and chickens

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Y H; Ogata, K; Sugimura, M [Hokkaido Univ., Sapporo (Japan)

    1979-05-01

    Neonatal ducks and chickens are exposed to a wholebody X-irradiation ranging from 100 R to 3,000 R at a dose-rate of 185 R per min. Lethal doses to 50% in 30 days are estimated to be 500 R for the ducks, while 800 R for the chickens. The ducks appear to be much more radiosensitive than the chickens. Histopathological observations of various organs of the exposed specimens after death reveal remarkable alterations: Particularly lymphoid organs are affected much more in the ducks than in the chickens at lesser doses than 1,000 R.

  19. Studies on the quality of duck meat sausages during refrigeration.

    Science.gov (United States)

    Naveen, Z; Naik, B R; Subramanyam, B V; Reddy, P M

    2016-01-01

    Duck farming is on the raise in the current scenario, but processed products from duck meat are still uncommon to find. Investigating the duck meat qualities during storage will provide information to enhance duck meat utilization. Development of ready-to-eat and ready-to-cook duck meat products is expected to increase and improve non-chicken meat-based protein. The Study was aimed to evaluate the changes in quality characteristics of duck meat sausages preserved by refrigeration (7 ± 1 °C). Duck meat sausages were prepared by utilizing raw and partially cooked duck meat with addition of soy flour at 10% level as a binder. Different quality characteristics like physical and chemical characteristics, proximate composition, and organoleptic characteristics were evaluated. Cooking loss of partially cooked meat sausages was lower than raw duck meat sausages, whereas emulsion stability and 2-thiobarbituric acid (TBA) values of raw duck meat sausages were lesser than partially cooked meat sausages. Cooking loss and emulsion stability decreased in both types of meat sausages, while, 2-TBA values increased as refrigerated storage progressed for 14 days. Percent moisture content of raw duck meat sausages was higher than partially cooked meat sausages, which decreased in both types of meat sausages as refrigerated storage progressed for 14 days. Percent crude protein (CP) and percent ether extract (EE) content of partially cooked duck meat sausages were higher than raw duck meat sausages. Regardless of type of meat used, refrigerated storage of sausages increased CP and EE up to 10th day but decreased upon further storage up to 14th day. Organoleptic scores for raw duck meat sausages were higher than partially cooked duck meat sausages and all the scores decreased with an increase in the storage period. However the scores were within the acceptable limits. The findings prove that, duck meat can be effectively acclaimed as an alternative avenue to meet the escalating

  20. Red fox predation on breeding ducks in midcontinent North America

    Science.gov (United States)

    Sargeant, Alan B.; Allen, Stephen H.; Eberhardt, Robert T.

    1984-01-01

    Red fox (Vulpes vulpes) predation on nesting ducks was assessed by examining 1,857 adult duck remains found at 1,432 fox rearing dens from 1968 to 1973. Dabbling ducks were much more vulnerable to foxes than diving ducks. Dabbling ducks (1,798) found at dens consisted of 27% blue-winged teals (Anas discors), 23% mallards (A. platyrhynchos), 20% northern pintails (A. acuta), 9% northern shovelers (Spatula clypeata), 8% gadwalls (A. strepera), 3% green-winged teals (A. crecca), 2% American wigeons (A. americana), and 10% unidentified. Relative abundance of individual species and nesting chronology were the most important factors affecting composition of ducks taken by foxes. Seventy-six percent of 1,376 adult dabbling ducks and 40% of 30 adult diving ducks for which sex was determined were hens. In western North Dakota and western South Dakota, 65% of mallard and northern pintail remains found at dens were hens compared with 76% in eastern North Dakota and eastern South Dakota (P fox predation rates on ducks. Predation rate indices ranged from 0.01 duck/den in Iowa to 1.80 ducks/den in eastern North Dakota. Average annual predation rate indices for dabbling ducks in a 3-county intensive study area in eastern North Dakota were closely correlated with May pond numbers (r = 0.874, P foxes than hens of late nesting species. Predation rate indices were expanded to estimate total numbers of ducks taken by fox families during the denning season. Estimated numbers of dabbling ducks taken annually by individual fox families in 2 physiographic regions comprising the intensive study area ranged from 16.1 to 65.9. Predation was highest during wet years and lowest during dry years and averaged lower, but was more variable, in the region where tillage was greatest and wetland water levels were least stable. Predation in the intensive study area averaged 2.97 adult dabbling ducks/ km2/year and represented an estimated average annual loss of 13.5% of hen and 4.5% of drake

  1. OPEC ducks quota issue amid glut worries

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This paper reports that the Organization of Petroleum Exporting Countries has ducked the question of reestablishing quotas despite the looming prospect of a second quarter oil price slide. OPEC ministers meeting in Vienna late last month approved continuing free-for-all production in the first quarter and ordered the ministerial monitoring committee to tackle the question of second quarter production levels when it meets in Geneva Feb. 12. Oil markets responded to the lack of action by dropping futures prices

  2. Novel duck parvovirus identified in Cherry Valley ducks (Anas platyrhynchos domesticus), China.

    Science.gov (United States)

    Li, Chuanfeng; Li, Qi; Chen, Zongyan; Liu, Guangqing

    2016-10-01

    An unknown infectious disease in Cherry Valley ducks (Anas platyrhynchos domesticus) characterized by short beak and strong growth retardation occurred in China during 2015. The causative agent of this disease, tentatively named duck short beak and dwarfism syndrome (DSBDS), as well as the evolutionary relationships between this causative agent and all currently known avian-origin parvoviruses were clarified by virus isolation, transmission electron microscope (TEM) observation, analysis of nuclear acid type, (RT-)PCR identification, whole genome sequencing, and NS1 protein sequences-based phylogenetic analyses. The results indicated that the causative agent of DSBDS is closely related with the goose parvovirus-like virus, which is divergent from all currently known avian-origin parvoviruses and should be a novel duck parvovirus (NDPV). Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Winter Weather Emergencies

    Science.gov (United States)

    Severe winter weather can lead to health and safety challenges. You may have to cope with Cold related health problems, including ... there are no guarantees of safety during winter weather emergencies, you can take actions to protect yourself. ...

  4. Winter maintenance performance measure.

    Science.gov (United States)

    2016-01-01

    The Winter Performance Index is a method of quantifying winter storm events and the DOTs response to them. : It is a valuable tool for evaluating the States maintenance practices, performing post-storm analysis, training : maintenance personnel...

  5. Winter weather demand considerations.

    Science.gov (United States)

    2015-04-01

    Winter weather has varied effects on travel behavior. Using 418 survey responses from the Northern Virginia : commuting area of Washington, D.C. and binary logit models, this study examines travel related changes under : different types of winter wea...

  6. 46 CFR 42.30-10 - Southern Winter Seasonal Zone.

    Science.gov (United States)

    2010-10-01

    ... Island; thence the rhumb line to Black Rock Point on Stewart Island; thence the rhumb line to the point... BY SEA Zones, Areas, and Seasonal Periods § 42.30-10 Southern Winter Seasonal Zone. (a) The northern boundary of the Southern Winter Seasonal Zone is the rhumb line from the east coast of the American...

  7. Carcass yields of two different strains of ducks raised in different altitude

    Science.gov (United States)

    Dillak, St. Y. F. G.; Mulyantini, N. G. A.; Sipahelut, G. M.; Lole, U. R.

    2018-02-01

    The objective of this research was to determine if there is a difference in performance and carcass yield between ducks of two different strains raised in different altitude. Ducks different strains (Muscovy vs Pekin ducks) and they raised either in high or low altitude (high altitude which was between 500 and 1000m vs low altitude which was below 500m). All ducks were given one of two different diet s and provided water ad libitum. The diets were: 1) commercial diet, and 2) local diet. There were three replicate per treatment and there were 5 ducks per replication. Ducks from each strain were standardized to a similar weight. The results show that Pekin ducks carcass performance was significantly better than Muscovy ducks. Ducks given diet 2 had significantly (Pabdominal fat percentage in Pekin ducks is significantly (Pabdominal fat percentage in Muscovy ducks.

  8. Winter-to-winter variations in indoor radon

    International Nuclear Information System (INIS)

    Mose, D.G.; Mushrush, G.W.; Kline, S.W.

    1989-01-01

    Indoor radon concentrations in northern Virginia and central Maryland show a strong dependence on weather. Winter tends to be associated with higher than average indoor radon, and summer with lower than average. However, compared to the winter of 1986-1987, the winter of 1987-1988 was warmer and drier. Consequently, winter-to-winter indoor radon decreased by about 25%. This winter-to-winter decrease is unexpectedly large, and simulates winter-to-summer variations that have been reported

  9. Susceptibility of Duck and Turkey to servere hypercapnic hypoxia

    NARCIS (Netherlands)

    Gerritzen, M.A.; Lambooij, E.; Reimert, H.G.M.; Stegeman, J.A.; Spruijt, B.M.

    2006-01-01

    Large groups of poultry, including ducks and turkeys, are killed for disease control purposes with CO2. In this study, we examined the physiological reaction of White Pekin ducks and turkeys to increasing CO2 concentrations. Additionally, we examined the suitability of killing both species with

  10. Molecular cloning and characterization of duck interleukin-17

    Science.gov (United States)

    Interleukin-17 (IL-17) belonging to the Th17 family is a proinflammatory cytokine produced by activated T cells. A 1034-bp cDNA encoding duck IL-17 (duIL-17) was cloned from ConA-activated splenic lymphocytes of ducks. The encoded protein, predicted to consisted of 169 amino acids, displayed a molec...

  11. Pig-duck-fish-azolla integration in La Union, Philippines

    OpenAIRE

    Gavina, L.D.

    1994-01-01

    Three studies on pig-duck-fish-azolla integration were conducted simultaneously in La Union, Philippines. Growth performance of pigs and ducks as affected by different levels of azolla meal in their feed, and that of tilapia (Oreochromis niloticus) under varying stocking rates are presented and discussed.

  12. Assessing genetic diversity and phylogeographic structure of duck ...

    African Journals Online (AJOL)

    In this study, the maternal genetic diversity and phylogenetic relationship of Nigerian duck populations were assessed. A total of 591 base pair fragment of the mitochondrial DNA (mtDNA) D-loop region of 87 indigenous ducks from two populations in Nigeria were analyzed. Seven haplotypes and 70 polymorphic sites were ...

  13. Interactions between nesting pileated woodpeckers and wood ducks

    Science.gov (United States)

    Richard N. Conner; Clifford E. Shackelford; Daniel Saenz; Richard R. Schaefer

    2001-01-01

    We observed interactions between a nesting pair of pileated woodpeckers (Dryocopus pileatus) and what appeared to be four pairs of wood ducks (Aix sponsa). Wood ducks regularly approached and attempted to enter an active pileated woodpecker nest cavity that contained three fully feathered young pileated woodpeckers. The male...

  14. Low Pathogenic Avian Influenza (H7N1) Transmission Between Wild Ducks and Domestic Ducks

    DEFF Research Database (Denmark)

    Therkildsen, O. R.; Jensen, Trine Hammer; Handberg, Kurt

    2011-01-01

    This article describes a virological investigation in a mixed flock of ducks and geese following detection of avian influenza virus antibodies in domestic geese. Low pathogenic H7N1 was found in both domestic and wild birds, indicating that transmission of virus was likely to have taken place...

  15. Arginine affects appetite via nitric oxide in ducks.

    Science.gov (United States)

    Wang, C; Hou, S S; Huang, W; Xu, T S; Rong, G H; Xie, M

    2014-08-01

    The objective of the study was to investigate the mechanism by which arginine regulates feed intake in Pekin ducks. In experiment 1, one hundred forty-four 1-d-old male Pekin ducks were randomly allotted to 3 dietary treatments with 6 replicate pens of 8 birds per pen. Birds in each group were fed a corn-corn gluten meal diet containing 0.65, 0.95, and 1.45% arginine. Ducks fed the diet containing 0.65% arginine had lower feed intake and plasma nitric oxide level (P ducks were allotted to 1 of 2 treatments. After 2 h fasting, birds in the 2 groups were intraperitoneally administrated saline and l-NG-nitro-arginine methyl ester HCl (L-NAME) for 3 d, respectively. Feed intake (P study implied that arginine modifies feeding behavior possibly through controlling endogenous synthesis of nitric oxide in Pekin ducks. © Poultry Science Association Inc.

  16. The Ratios of Pre-emulsified Duck Skin for Optimized Processing of Restructured Ham.

    Science.gov (United States)

    Shim, Jae-Yun; Kim, Tae-Kyung; Kim, Young-Boong; Jeon, Ki-Hong; Ahn, Kwang-Il; Paik, Hyun-Dong; Choi, Yun-Sang

    2018-02-01

    The purpose of this study was to investigate the quality of duck ham formulated with duck skin through the pre-emulsification process. The experiments to investigate the quality characteristics of duck ham were carried out to measure proximate composition, cooking loss, emulsion stability, pH, color, texture profile analysis, apparent viscosity, and sensory characteristics. Duck ham was prepared with various ratios of duck skin in pre-emulsion as follows: Control (duct skin 30%), T1 (duck skin 20% + pre-emulsified duck skin 10%), T2 (duck skin 15% + pre-emulsified duck skin 15%), T3 (duck skin 10% + pre-emulsified duck skin 20%), and T4 (pre-emulsified duck skin 30%). As the ratio of duck skin to pre-emulsified skin changed, the quality of duck ham in terms of moisture content, fat content, cooking loss, emulsion stability, lightness, textural analysis, apparent viscosity, and overall acceptability changed. The moisture content of T2 was the highest ( p ham and 1:1 ratio of duck skin and pre-emulsified skin was the proper ratio to improve the quality characteristics of duck ham.

  17. Band reporting probablilities of mallards, American black ducks, and wood ducks in eastern North America

    Science.gov (United States)

    Garrettson, Pamela R.; Raftovich, Robert V.; Hines, James; Zimmerman, Guthrie S.

    2014-01-01

    Estimates of band reporting probabilities are used for managing North American waterfowl to convert band recovery probabilities into harvest probabilities, which are used to set harvest regulations. Band reporting probability is the probability that someone who has shot and retrieved a banded bird will report the band. This probability can vary relative to a number of factors, particularly the inscription on the band and the ease with which it can be reported. Other factors, such as geographic reporting region, and species and sex of the bird may also play a role. We tested whether reporting probabilities of wood ducks (Aix sponsa) and American black ducks (black ducks; Anas rubripes) differed from those of mallards (Anas platyrhynchos) and whether band reporting varied geographically or by the sex of the banded bird. In the analysis of spatially comparable wood duck and mallard data, a band reporting probability of 0.73 (95% CI = 0.67–0.78) was appropriate for use across species, sex, and reporting region within the United States. In the black duck–mallard comparison, the band reporting probability of black ducks in Eastern Canada (0.50, 95% CI = 0.44–0.57) was lower than in the Eastern United States (0.73, 95% CI = 0.62–0.83). These estimates reflected an increase in overall band reporting probability following the addition of a toll-free telephone number to band inscriptions. Lower reporting in Eastern Canada may be because of cultural, linguistic, or logistical barriers.

  18. Determinants of breeding distributions of ducks

    Science.gov (United States)

    Johnson, D.H.; Grier, J.W.

    1988-01-01

    The settling of breeding habitat by migratory waterfowl is a topic of both theoretical and practical interest. We use the results of surveys conducted annually during 1955-81 in major breeding areas to examine the factors that affect the distributions of 10 common North American duck species. Three patterns of settling are described: homing, opportunistic, and flexible. Homing is generally more pronounced among species that use more stable (more predictable) wetlands, such as the redhead (Aythya americana), canvasback (A. valisineria), lesser scaup (A. affinis), mallard (Anas platyrhynchos), gadwall (Anas strepera), and northern shoveler (Anas clypeata). Opportunistic settling is more prevalent among species that use less stable (less predictable) wetlands, such as northern pintail (Anas acuta) and blue-winged teal (Anas discors). Flexible settling is exhibited to various degrees by most species.The 10 species are shown to fall along a natural ordination reflecting different life history characteristics. Average values of indices of r- and K-selection indicated that pintail, mallard, blue-winged teal, and shoveler have the most features associated with unstable or unpredictable environments. Gadwall, American wigeon (Anas americana), and green-winged teal (Anas crecca) were intermediate, and attributes of the diving ducks were associated with the use of stable or predictable environments.Some species--notably mallard, gadwall, blue-winged teal, redhead, and canvasback--tend to fill available breeding habitat first in the central portions of their range, and secondly in peripheral areas. Other species--American wigeon, green-winged teal, northern shoveler, northern pintail, and lesser scaup--fill their habitat in the order it is encountered during spring migration.Age and sex classes within species vary in their settling pattern. Some of this variation can be predicted from the mating systems of ducks in which breeding females, especially successful ones, have a

  19. Effects of dietary vanadium in mallard ducks

    Science.gov (United States)

    White, D.H.; Dieter, M.P.

    1978-01-01

    Adult mallard ducks fed 0, 1, 10, or 100 ppm vanadyl sulfate in the diet were sacrificed after 12 wk on treatment; tissues were analyzed for vanadium. No birds died during the study and body weights did not change. Vanadium accumulated to higher concentrations in the bone and liver than in other tissues. Concentrations in bones of hens were five times those in bones of drakes, suggesting an interaction between vanadium and calcium mobilization in laying hens. Vanadium concentrations in most tissues were significantly correlated and increased with treatment level. Lipid metabolism was altered in laying hens fed 100 ppm vanadium. Very little vanadium accumulated in the eggs of laying hens.

  20. Data set incongruence and correlated character evolution: An example of functional convergence in the hind-limbs of stifftail diving ducks

    Science.gov (United States)

    McCracken, K.G.; Harshman, J.; Mcclellan, D.A.; Afton, A.D.

    1999-01-01

    The unwitting inclusion of convergent characters in phylogenetic estimates poses a serious problem for efforts to recover phylogeny. Convergence is not inscrutable, however, particularly when one group of characters tracks phylogeny and another set tracks adaptive history. In such cases, convergent characters may be correlated with one or a few functional anatomical units and readily identifiable by using comparative methods. Stifftail ducks (Oxyurinae) offer one such opportunity to study correlated character evolution and function in the context of phylogenetic reconstruction. Morphological analyses place stifftail ducks as part of a large clade of diving ducks that includes the sea ducks (Mergini), Hymenolaimus, Merganetta, and Tachyeres, and possibly the pochards (Aythyini). Molecular analyses, on the other hand, place stifftails far from other diving ducks and suggest, moreover, that stifftails are polyphyletic. Mitochondrial cytochrome b gene sequences of eight stifftail species traditionally supposed to form a clade were compared with each other and with sequences from 50 other anseriform and galliform species. Stifftail ducks are not the sister group of sea ducks but lie outside the typical ducks (Anatinae). Of the four traditional stifftail genera, monophyly of Oxyura and its sister group relationship with Nomonyx are strongly supported. Heteronetta probably is the sister group of that clade, but support is weak. Biziura is not a true stifftail. Within Oxyura, Old World species (O. australis, O. leucocephala, O. mnccoa) appear to form a clade, with New World species (O. jamaicensis, O. vittata) branching basally. Incongruence between molecules and morphology is interpreted to be the result of adaptive specialization and functional convergence in the hind limbs of Biziura and true stifftails. When morphological characters are divided into classes, only hind-limb characters are significantly in conflict with the molecular tree. Likewise, null models of

  1. Multiple losses of flight and recent speciation in steamer ducks

    Science.gov (United States)

    Fulton, Tara L.; Letts, Brandon; Shapiro, Beth

    2012-01-01

    Steamer ducks (Tachyeres) comprise four species, three of which are flightless. The flightless species are believed to have diverged from a flying common ancestor during the Late Pleistocene; however, their taxonomy remains contentious. Of particular interest is the previously unstudied population of flying steamer ducks in the Falkland Islands. We present the first genetic data from this insular population, and illustrate that the flying and flightless steamer ducks on the Falkland Islands are genetically indistinguishable, in contrast to their traditional classification as separate species. The three species that reside in continental South America form a genetically distinct lineage from the Falkland Island ducks. The Falkland steamer ducks diverged from their continental relatives 2.2–0.6 million years ago, coincident with a probable land bridge connecting the Falkland Islands to the mainland. The three continental species share a common ancestor approximately 15 000 years ago, possibly owing to isolation during a recent glacial advance. The continental steamer duck species are not reciprocally monophyletic, but show some amount of genetic differentiation between them. Each lineage of Tachyeres represents a different stage between flight and flightlessness. Their phylogenetic relationships suggest multiple losses of flight and/or long-term persistence of mixed-flight capability. As such, steamer ducks may provide a model system to study the evolution of flightlessness. PMID:22319122

  2. Properties of duck meat sausages supplemented with cereal flours.

    Science.gov (United States)

    Yang, H S; Ali, M S; Jeong, J Y; Moon, S H; Hwang, Y H; Park, G B; Joo, S T

    2009-07-01

    Duck meat sausages were prepared using 10% beef fat (FDS) and 10% hydrated cereal flours including rice (RDS), wheat, corn, millet, and barley to replace fat. Control duck sausages (DS) were also prepared only with duck meat and duck meat plus 10% beef fat. Results showed that protein and fat contents significantly decreased and total expressible fluid reduced with the addition of cereal flours in duck sausage batters. The FDS had higher fat content and lower pH compared with others. Duck sausages with 10% supplemented wheat flour showed the lowest cooking loss among sausages and had similar redness and chroma values to FDS and DS. Texture analysis indicated that hardness of duck sausage significantly decreased when cereal flours and beef fat were added. In particular, RDS showed the lowest values for all texture measurements compared with others. Result of moisture absorption capacity suggested that the decrease in hardness in RDS was due to higher moisture retention for rice flour treatment. Sensory evaluation indicated that DS had significantly lower overall acceptability than RDS, due to its off-flavor, whereas RDS had higher overall acceptability than DS.

  3. Molting characteristics of crossbreds between Alabio and Pekin ducks

    Directory of Open Access Journals (Sweden)

    Susanti T

    2015-03-01

    Full Text Available Molting is a problem for duck farmers, during which the ducks stop laying eggs. Molting characteristics may be altered through crossing between non-molting to molting ducks. The purpose of this study was to evaluate molting characteristics of the crossing between Alabio and Pekin ducks. The materials used were 90 female AP (Alabio males x Pekin females and 90 female PA (Pekin males x Alabio females, 25 female Alabio and 25 female Pekin ducks. The ducks were housed in individual cages at the Indonesian Research Institute for Animal Production, Ciawi Bogor. Variables measured were the length of molting and egg production in 30 weeks, data were analyzed using ANOVA and followed by the estimation of the value of heterosis. Result showed that the molting of Pekin ducks was 71.31±9.36 days, it was longer than Alabio, AP or PA ducks, which were respectively 42.44±8.59, 43.63±4.88 and 49.35±4.85 days (P<0.01. Egg production of Pekin duck (56.41±4.59 was significantly lower (P<0.01 than that of Alabio, AP or PA, which were 72.48±3.24, 83.75±1.39 and 76.12±1.68 respectively. The heterosis of molting period of AP was higher than that of PA (-23.29 vs -13.23%. The heterosis of egg production of AP was higher than PA (29.96 vs 18.12%. It is concluded that the AP crossbred could be utilized as the initial population to produce a superior line characterized by high egg production and controllable molting.

  4. Influence of nutrients on feed intake and condition of captive canvasbacks in winter

    Science.gov (United States)

    Perry, M.C.; Kuenzel, W.J.; Williams, B.K.; Serafin, J.A.

    1986-01-01

    Dramatic changes in the food habits and distribution of canvasbacks (Aythya valisineria) in Chesapeake Bay during the 1970's generated a need to evaluate the nutritional value of food items and the requirements of this species on its wintering grounds. Groups of captive canvasbacks were maintained ad libitum on 5 diets during the winters of 1978-79 and 1979-80 to evaluate the effects of varying protein and energy levels on feed intake and condition. Feed intake during the 1979-80 winter was 42% greater for those ducks fed the low energy (1,543 kcal/kg) diet than for those fed the high energy (3,638 kcal/kg) diet. Canvasbacks fed the high energy diet, however, consumed 317 kcal/bird day, whereas those fed the low energy diet consumed only 191 kcal/bird day. Body weight of males and females did not differ among groups fed different diets, but there were seasonal differences (P < 0.05) for both sexes aggregated across diets. Data from this study indicate that canvasbacks may be unable to adjust intake rates to compensate for low energy foods and subsequently may store less fat or modify behavior. However, decreased weight, feed intake, and activity of ducks fed ad libitum rations occurred in mid-winter irrespective of diet quality and appeared to be an endogenous component of their annual cycle that persists in captivity. These changes apparently have a selective advantage of increasing the probability of survival in ducks by decreasing energy expenditure during periods of winter stress.

  5. Winters fuels report

    International Nuclear Information System (INIS)

    1995-01-01

    The outlook for distillate fuel oil this winter is for increased demand and a return to normal inventory patterns, assuming a resumption of normal, cooler weather than last winter. With industrial production expected to grow slightly from last winter's pace, overall consumption is projected to increase 3 percent from last winter, to 3.4 million barrels per day during the heating season (October 1, 1995-March 31, 1996). Much of the supply win come from stock drawdowns and refinery production. Estimates for the winter are from the Energy Information Administration's (EIA) 4th Quarter 1995 Short-Tenn Energy Outlook (STEO) Mid-World Oil Price Case forecast. Inventories in place on September 30, 1995, of 132 million barrels were 9 percent below the unusually high year-earlier level. Inventories of high-sulfur distillate fuel oil, the principal type used for heating, were 13 percent lower than a year earlier. Supply problems are not anticipated because refinery production and the ready availability of imports should be adequate to meet demand. Residential heating off prices are expected to be somewhat higher than last winter's, as the effects of lower crude oil prices are offset by lower distillate inventories. Heating oil is forecast to average $0.92 per gallon, the highest price since the winter of 1992-93. Diesel fuel (including tax) is predicted to be slightly higher than last year at $1.13 per gallon. This article focuses on the winter assessment for distillate fuel oil, how well last year's STEO winter outlook compared to actual events, and expectations for the coming winter. Additional analyses include regional low-sulfur and high-sulfur distillate supply, demand, and prices, and recent trends in distillate fuel oil inventories

  6. Replication cycle of duck hepatitis A virus type 1 in duck embryonic hepatocytes

    International Nuclear Information System (INIS)

    Yao, Fangke; Chen, Yun; Shi, Jintong; Ming, Ke; Liu, Jiaguo; Xiong, Wen; Song, Meiyun; Du, Hongxu; Wang, Yixuan; Zhang, Shuaibin; Wu, Yi; Wang, Deyun; Hu, Yuanliang

    2016-01-01

    Duck hepatitis A virus type 1 (DHAV-1) is an important agent of duck viral hepatitis. Until recently, the replication cycle of DHAV-1 is still unknown. Here duck embryonic hepatocytes infected with DHAV-1 were collected at different time points, and dynamic changes of the relative DHAV-1 gene expression during replication were detected by real-time PCR. And the morphology of hepatocytes infected with DHAV was evaluated by electron microscope. The result suggested that the adsorption of DHAV-1 saturated at 90 min post-infection, and the virus particles with size of about 50 nm including more than 20 nm of vacuum drying gold were observed on the infected cells surface. What's more, the replication lasted around 13 h after the early protein synthesis for about 5 h, and the release of DHAV-1 was in steady state after 32 h. The replication cycle will enrich the data for DVH control and provide the foundation for future studies. - Highlights: • This is the first description of the replication cycle of DHAV-1. • Firstly find that DHAV-1 adsorption saturated at 90 min post-infection. • The replication lasted around 13 h after early protein synthesis for about 5 h. • The release of DHAV-1 was in steady state after 32 h.

  7. Replication cycle of duck hepatitis A virus type 1 in duck embryonic hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Fangke; Chen, Yun; Shi, Jintong; Ming, Ke; Liu, Jiaguo, E-mail: liujiaguo@njau.edu.cn; Xiong, Wen; Song, Meiyun; Du, Hongxu; Wang, Yixuan; Zhang, Shuaibin; Wu, Yi; Wang, Deyun; Hu, Yuanliang

    2016-04-15

    Duck hepatitis A virus type 1 (DHAV-1) is an important agent of duck viral hepatitis. Until recently, the replication cycle of DHAV-1 is still unknown. Here duck embryonic hepatocytes infected with DHAV-1 were collected at different time points, and dynamic changes of the relative DHAV-1 gene expression during replication were detected by real-time PCR. And the morphology of hepatocytes infected with DHAV was evaluated by electron microscope. The result suggested that the adsorption of DHAV-1 saturated at 90 min post-infection, and the virus particles with size of about 50 nm including more than 20 nm of vacuum drying gold were observed on the infected cells surface. What's more, the replication lasted around 13 h after the early protein synthesis for about 5 h, and the release of DHAV-1 was in steady state after 32 h. The replication cycle will enrich the data for DVH control and provide the foundation for future studies. - Highlights: • This is the first description of the replication cycle of DHAV-1. • Firstly find that DHAV-1 adsorption saturated at 90 min post-infection. • The replication lasted around 13 h after early protein synthesis for about 5 h. • The release of DHAV-1 was in steady state after 32 h.

  8. Sex determination of duck embryos: observations on syrinx development

    Science.gov (United States)

    Wilson, Robert E.; Sonsthagen, Sarah A.; Franson, J. Christian

    2013-01-01

    Ducks exhibit sexual dimorphism in vocal anatomy. Asymmetrical ossification of the syrinx (bulla syringealis) is discernable at about 10 days of age in male Pekin duck (Anas platyrhynchos domestica) embryos, but information is lacking on the early development of the bulla in wild ducks. To evaluate the reliability of this characteristic for sexing developing embryos, we examined the syrinx of dead embryos and compared results with molecular sexing techniques in high arctic nesting Common Eiders (Somateria mollissima). Embryos 8 days or older were accurately (100%) sexed based on the presence/absence of a bulla, 2 days earlier than Pekin duck. The use of the tracheal bulla can be a valuable technique when sex identification of embryos or young ducklings is required.

  9. Lead shot pellets dispersed by hunters: ingested by ducks

    Energy Technology Data Exchange (ETDEWEB)

    Danell, K [Univ. of Umea, Sweden; Andersson, A; Marcstrom, V

    1977-01-01

    Many of the lead pellets shot by waterfowl hunters over shores and waters fall on the feeding grounds of ducks and geese. These pellets, picked up and ingested by the birds, can remain in the gizzard where they are eroded by mechanical and chemical action. In some cases the bird absorbs enough lead to cause lead poisoning. This report describes the incidence of ingested lead shot pellets found in 928 ducks collected in Sweden during hunting season. Pellets were found in both dabbling and diving ducks and were present in birds from six of the eight localities sampled. Usually one or two pellets were found but some ducks contained up to 62 pellets. As the incidence of ingested pellets in the present study is approximately the same as that found in North America, where the annual duck loss due to lead poisoning is estimated to be 2 to 3 percent of the population, it may be assumed that lead poisoning is a mortality factor for Swedish ducks also.

  10. Updating movement estimates for American black ducks (Anas rubripes

    Directory of Open Access Journals (Sweden)

    Orin J. Robinson

    2016-03-01

    Full Text Available Understanding migratory connectivity for species of concern is of great importance if we are to implement management aimed at conserving them. New methods are improving our understanding of migration; however, banding (ringing data is by far the most widely available and accessible movement data for researchers. Here, we use band recovery data for American black ducks (Anas rubripes from 1951–2011 and analyze their movement among seven management regions using a hierarchical Bayesian framework. We showed that black ducks generally exhibit flyway fidelity, and that many black ducks, regardless of breeding region, stopover or overwinter on the Atlantic coast of the United States. We also show that a non-trivial portion of the continental black duck population either does not move at all or moves to the north during the fall migration (they typically move to the south. The results of this analysis will be used in a projection modeling context to evaluate how habitat or harvest management actions in one region would propagate throughout the continental population of black ducks. This analysis may provide a guide for future research and help inform management efforts for black ducks as well as other migratory species.

  11. Winter Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Winter Bottom Trawl Survey was initiated in 1992 and covered offshore areas from the Mid-Atlantic to Georges Bank. Inshore strata were covered...

  12. Deer Wintering Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — Deer winter habitat is critical to the long term survival of white-tailed deer (Odocoileus virginianus) in Vermont. Being near the northern extreme of the...

  13. Duck enteritis virus glycoprotein D and B DNA vaccines induce immune responses and immunoprotection in Pekin ducks.

    Science.gov (United States)

    Zhao, Yan; Cao, Yongsheng; Cui, Lihong; Ma, Bo; Mu, Xiaoyu; Li, Yanwei; Zhang, Zhihui; Li, Dan; Wei, Wei; Gao, Mingchun; Wang, Junwei

    2014-01-01

    DNA vaccine is a promising strategy for protection against virus infection. However, little is known on the efficacy of vaccination with two plasmids for expressing the glycoprotein D (gD) and glycoprotein B (gB) of duck enteritis virus (DEV) in inducing immune response and immunoprotection against virulent virus infection in Pekin ducks. In this study, two eukaryotic expressing plasmids of pcDNA3.1-gB and pcDNA3.1-gD were constructed. Following transfection, the gB and gD expressions in DF1 cells were detected. Groups of ducks were vaccinated with pcDNA3.1-gB and/or pcDNA3.1-gD, and boosted with the same vaccine on day 14 post primary vaccination. We found that intramuscular vaccinations with pcDNA3.1-gB and/or pcDNA3.1-gD, but not control plasmid, stimulated a high frequency of CD4+ and CD8+ T cells in Pekin ducks, particularly with both plasmids. Similarly, vaccination with these plasmids, particularly with both plasmids, promoted higher levels of neutralization antibodies against DEV in Pekin ducks. More importantly, vaccination with both plasmids significantly reduced the virulent DEV-induced mortality in Pekin ducks. Our data indicated that vaccination with plasmids for expressing both gB and gD induced potent cellular and humoral immunity against DEV in Pekin ducks. Therefore, this vaccination strategy may be used for the prevention of DEV infection in Pekin ducks.

  14. MORPHOLOGY AND GENETIC DIVERSITY OF MITOCHONDRIAL DNA D-LOOP REGION USING PCR-RFLP ANALYSIS IN MAGELANG DUCK AND OTHER NATIVE DUCK

    Directory of Open Access Journals (Sweden)

    D. Purwantini

    2014-10-01

    Full Text Available The aim of this study was to investigate the different of plumage colors on morphological diversityof Magelang duck and genetic diversity using PCR-RFLP mtDNA D-loop region analysis of Magelangduck and four others native duck population (Tegal, Mojosari, Bali and Alabio duck in Indonesia. Bloodsample was taken from 50 Magelang ducks and 20 of each native ducks. Morphological characteristicsof body measurement, production ability and egg quality of Magelang duck were analyzed usingCompletely Randomized Design with 11 plumage colors as treatments. PCR technique was administeredto amplify fragments in mtDNA D-loop region and PCR products were digested with endonucleaserestriction enzyme AluI and HaeIII. The result showed that morphology diversity of Magelang duck wasstatistically affected by different plumage colors. PCR-RFLP analysis using AluI and HaeIII restrictionenzyme resulted in six combinations of restriction fragment pattern shown in six haplotypes (A, B, C, D,E and F. Haplotype difference showed genetic diversity in the population of Magelang duck and theother native ducks. In conclusion, the different plumage colors affected morphology diversity ofMagelang duck. Genetic diversity of Indonesian native duck population could be identified by usingPCR-RFLP analysis on mtDNA D-loop region.

  15. Cross-sectional serosurvey of avian influenza antibodies presence in domestic ducks of Kathmandu, Nepal.

    Science.gov (United States)

    Karki, S; Lupiani, B; Budke, C M; Manandhar, S; Ivanek, R

    2014-09-01

    Kathmandu, Nepal has been classified as a high-risk area for highly pathogenic avian influenza (HPAI) by the Nepali Government. While ducks have an important role in the transmission of avian influenza viruses (AIV), including HPAI, seroprevalence of antibodies to AIV in domestic ducks of Kathmandu has never been assessed. The objectives of this study were (i) to estimate the prevalence of seroconversion to AIV in domestic ducks in major duck-raising areas of Kathmandu and (ii) to assess the effect of age, sex, presence of swine and the number of ducks on the farm on the carriage of antibodies to AIV in these ducks. From April through July of 2011, a cross-sectional study was conducted and a total of 310 ducks in the major duck-raising areas of Kathmandu were sampled. The estimated prevalence of AIV antibodies was 27.2% [95% confidence interval (CI): 24.6-29.5]. Of 62 enrolled farms, 42% had at least one seropositive duck. Half of the enrolled farms also kept pigs of which 52% had at least one seropositive duck. Bivariate analysis indicated association between ducks' seroconversion to AIV and their age, sex and farm size. However, the final multivariable model, after controlling for clustering of ducks within farms, identified age as the only significant risk factor. Based on this model, ducks older than 1 year of age were more likely to be seropositive compared to ducks ducks in the major duck-raising areas of Kathmandu and identify a high-risk group that can be targeted in surveillance activities. Future studies should be conducted to differentiate the subtypes of AIV present among domestic ducks in Kathmandu, with particular interest in the presence of HPAI viruses. © 2014 Blackwell Verlag GmbH.

  16. The Characteristics of Meat Duck, Problems and Prevention of Off Flavor Due to Lipid Oxidation

    Directory of Open Access Journals (Sweden)

    Procula R Matitaputty

    2010-09-01

    Full Text Available Source of poultry meat in Indonesia is currently dominated by chicken while local resources such as ducks have the potential to grow and be used as an alternative meat producer. Duck contribution towards the provision of a relatively small meat of 2.29%, compared with free-range chicken to reachs 20.33%. Sources of duck meat in Indonesia comes from local duck, and culled female ducks. Acceptance of most local duck meat is still relatively low, although in some areas local duck dishes are excellent. Meat ducks are generally less desirable, because taste and smell is different from chicken. Because consumers are not accustomed to the taste of typical meat, especially those that give the sensation of irregularities off meat – flavor or smell fishy/ rancid. Similarly, the color of duck meat is darker than that of chicken meat, high fat content of about 2.7 to 6.8%, which also influences consumer preferences. The high fat content, especially acid-unsaturated fatty acids in meat duck gives a tendency to produce off – flavors. Efforts to increase the consumption of duck meat should be based on the cause of the lack of acceptance by consumers. The smell of rancid meat duck is the most dominant cause of which is not liked by consumers. Efforts to reduce the off flavor of duck meat could be by adding antioxidant in feed stuffs.

  17. Treatment of duck house wastewater by a pilot-scale sequencing batch reactor system for sustainable duck production.

    Science.gov (United States)

    Su, Jung-Jeng; Huang, Jeng-Fang; Wang, Yi-Lei; Hong, Yu-Ya

    2018-06-15

    The objective of this study is trying to solve water pollution problems related to duck house wastewater by developing a novel duck house wastewater treatment technology. A pilot-scale sequencing batch reactor (SBR) system using different hydraulic retention times (HRTs) for treating duck house wastewater was developed and applied in this study. Experimental results showed that removal efficiency of chemical oxygen demand in untreated duck house wastewater was 98.4, 98.4, 87.8, and 72.5% for the different HRTs of 5, 3, 1, and 0.5 d, respectively. In addition, removal efficiency of biochemical oxygen demand in untreated duck house wastewater was 99.6, 99.3, 90.4, and 58.0%, respectively. The pilot-scale SBR system was effective and deemed capable to be applied to treat duck house wastewater. It is feasible to apply an automatic SBR system on site based on the previous case study of the farm-scale automatic SBR systems for piggery wastewater treatment.

  18. Cloning, characterization and expression of Peking duck fatty acid synthase during adipocyte differentiation

    Directory of Open Access Journals (Sweden)

    Fang Ding

    2014-11-01

    Conclusion: We have successfully cloned and characterized Peking duck FAS. FAS was induced during adipocyte differentiation and by oleic acid treatment. These findings suggest that Peking duck FAS plays a similar role to mammalian FAS during adipocyte differentiation.

  19. Study on rural duck production systems in selected areas of Bangladesh

    DEFF Research Database (Denmark)

    Khanum, J.; Chwalibog, André; Huque, K.S.

    2005-01-01

    The present study was carried out to investigate scavenging duck production systems in two regions (Netrokona Sadar Upazila and Sundargonj Upazila) of Bangladesh. Feeding systems and availability of feed for raising ducks, production performance of scaavenging ducks and profitability of raising...... ducks were evaluated. Information was collected from the farmers through a questionnaire. All the farmers of Sundargonj Upazila used mixed feed compund, but in Netrokona only 14% of farmers fed mixed feed to their ducks. The rest was either paddy or wheat alone or a mixture of both. Deshi (local) ducks...... were mostly used in Netrokona but in Sundargonj, farmers mostly raise exotic ducks. The farmers of Sundargonj area increased the amount of feed with the increase of age of their ducks, but the farmers of Netrokona decreased the amount of feed. The mortality rate in Netrokona was 27.1% but in Sundargonj...

  20. Economics of duck marketing in Oyo State | Saka | African Journal of ...

    African Journals Online (AJOL)

    Economics of duck marketing in Oyo State. ... The marketing survey involved 50 duck traders selected from Ibadan, Oyo and Ogbomoso. Majority (72%) of the marketers procured ... EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL ...

  1. Experimental reproduction of an Enterococcus cecorum infection in Pekin ducks.

    Science.gov (United States)

    Jung, Arne; Metzner, Martin; Köhler-Repp, Dagmar; Rautenschlein, Silke

    2013-12-01

    Enterococcus cecorum (EC) was thus far only known as a pathogen for broilers and broiler breeders. Recently there was evidence of EC field outbreaks in Pekin duck flocks in Germany. In this study we experimentally reproduced an EC infection in Pekin ducks. At 12 days post hatch, groups of Pekin ducks were infected orally, via the thoracic air sac or intravenously with 1.5 × 10(9) colony-forming units (CFU) of EC per bird or via the air sac with 8.5 × 10(5) or 8.5 × 10(7) CFU per bird. Ducks of the intravenously infected group showed 100% mortality after 2 days post infection. The air sac inoculated high-dose group exhibited a mortality rate of 67%. Birds that were infected with 8.5 × 10(5) and 8.5 × 10(7) CFU showed 6.7% mortality after 7 days post infection. Dead birds displayed pneumonia, airsacculitis, pericarditis and splenitis and EC was re-isolated from these organs. Surviving birds of all groups apart from the orally infected ducks demonstrated clinical signs such as huddling, reduced mobility and diarrhoea. Furthermore, they showed gross pathological lesions including airsacculitis and splenitis and lower bodyweights than the control group at necropsy on days 7, 14 and 21 post infection. The present study clearly confirms that EC is pathogenic for Pekin ducks after experimental infection via the intravenous route or the respiratory tract. EC therefore has to be considered as an emerging avian pathogen not only in broilers but also in Pekin ducks.

  2. Differential gene expression analysis of in vitro duck hepatitis B virus infected primary duck hepatocyte cultures

    Directory of Open Access Journals (Sweden)

    Issac Aneesh

    2011-07-01

    Full Text Available Abstract Background The human hepatitis B virus (HBV, a member of the hepadna viridae, causes acute or chronic hepatitis B, and hepatocellular carcinoma (HCC. The duck hepatitis B virus (DHBV infection, a dependable and reproducible model for hepadna viral studies, does not result in HCC unlike chronic HBV infection. Information on differential gene expression in DHBV infection might help to compare corresponding changes during HBV infection, and to delineate the reasons for this difference. Findings A subtractive hybridization cDNA library screening of in vitro DHBV infected, cultured primary duck hepatocytes (PDH identified cDNAs of 42 up-regulated and 36 down-regulated genes coding for proteins associated with signal transduction, cellular respiration, transcription, translation, ubiquitin/proteasome pathway, apoptosis, and membrane and cytoskeletal organization. Those coding for both novel as well as previously reported proteins in HBV/DHBV infection were present in the library. An inverse modulation of the cDNAs of ten proteins, reported to play role in human HCC, such as that of Y-box binding protein1, Platelet-activating factor acetylhydrolase isoform 1B, ribosomal protein L35a, Ferritin, α-enolase, Acid α-glucosidase and Caspase 3, copper-zinc superoxide dismutase (CuZnSOD, Filamin and Pyruvate dehydrogenase, was also observed in this in vitro study. Conclusions The present study identified cDNAs of a number of genes that are differentially modulated in in vitro DHBV infection of primary duck hepatocytes. Further correlation of this differential gene expression in in vivo infection models would be valuable to understand the little known aspects of the hepadnavirus biology.

  3. Epitope Identification and Application for Diagnosis of Duck Tembusu Virus Infections in Ducks

    Directory of Open Access Journals (Sweden)

    Chenxi Li

    2016-11-01

    Full Text Available Duck Tembusu virus (DTMUV causes substantial egg drop disease. DTMUV was first identified in China and rapidly spread to Malaysia and Thailand. The antigenicity of the DTMUV E protein has not yet been characterized. Here, we investigated antigenic sites on the E protein using the non-neutralizing monoclonal antibodies (mAbs 1F3 and 1A5. Two minimal epitopes were mapped to 221LD/NLPW225 and 87YAEYI91 by using phage display and mutagenesis. DTMUV-positive duck sera reacted with the epitopes, thus indicating the importance of the minimal amino acids of the epitopes for antibody-epitope binding. The performance of the dot blotting assay with the corresponding positive sera indicated that YAEYI was DTMUV type-specific, whereas 221LD/NLPW225 was a cross-reactive epitope for West Nile virus (WNV, dengue virus (DENV, and Japanese encephalitis virus (JEV and corresponded to conserved and variable amino acid sequences among these strains. The structure model of the E protein revealed that YAEYI and LD/NLPW were located on domain (D II, which confirmed that DII might contain a type-specific non-neutralizing epitope. The YAEYI epitope-based antigen demonstrated its diagnostic potential by reacting with high specificity to serum samples obtained from DTMUV-infected ducks. Based on these observations, a YAEYI-based serological test could be used for DTMUV surveillance and could differentiate DTMUV infections from JEV or WNV infections. These findings provide new insights into the organization of epitopes on flavivirus E proteins that might be valuable for the development of epitope-based serological diagnostic tests for DTMUV.

  4. Winter distribution of Calanus finmarchicus in the Northeast Atlantic

    DEFF Research Database (Denmark)

    Heath, M.R.; Fraser, J.G.; Gislason, A.

    2000-01-01

    Data from plankton sampling and Optical Plankton Counter deployments during six cruises between December of 1994 and 1999 have been used to derive a composite three-dimensional distribution of the abundance of Calanus finmarchicus during winter (December-January) in the Norwegian Sea and Northeast...... Northeast Atlantic, the concentration of wintering animals is around 30% of that in the Norwegian Sea and the vertical distribution is more diffuse and on average deeper. Modelling studies have shown that the overwinter distribution and transport are key factors determining the spatial persistence of C...

  5. Functional Characteristics of Spent Duck Meat for Use in Emulsion-Type Meat Products

    OpenAIRE

    Juni Sumarmono; Samsu Wasito

    2010-01-01

    Spent ducks produce nutritive meat; however the meat possesses undesirable characteristics such as strong odor and tough. Hence, appropriate yet simple processing technologies need to be developed in order to maximize the use of duck meat. The experiment was conducted to evaluate functional characteristics of spent duck meat as raw material for the production of emulsion-type meat products, such as nugget and sausage. Chilled carcasses of 96 spent ducks were deboned manually, then mixed thor...

  6. The nuclear winter

    International Nuclear Information System (INIS)

    Velikhow, Y.P.

    1986-01-01

    Nuclear winter is an example of possible secondary effects, and if we speak of secondary we are thinking of small-scale second-order effects, but a nuclear winter is not a second-order effect. If you calculate the amount of heat produced by a nuclear explosion, it is a very small amount which does not have any chance of changing the Earth's climate, but a nuclear explosion drives or stars some new mechanism - the mechanism of nuclear winter - after 100 megatons of dust are transferred to the upper atmosphere. Another example of such amplification is radioactive fall-out, especially long-life radioactive fall-out after the possible elimination of the nuclear power industry, nuclear storage and distribution of storage waste around the globe. This is a very powerful amplification mechanism

  7. Hydropericardium Hepatitis Syndrome Emerged in Cherry Valley Ducks in China.

    Science.gov (United States)

    Chen, H; Dou, Y; Zheng, X; Tang, Y; Zhang, M; Zhang, Y; Wang, Z; Diao, Y

    2017-08-01

    Since June 2015, a highly pathogenic disease occurred in duck flocks in China, causing pericardial effusion, enlarged discoloured liver, renal enlargement and haemorrhagic lung with a mortality ranging from 5% to 20%. Previous study confirmed that Fowl adenovirus group C (FAdV-C) and some field FAdVs isolates had been identified as causative agents of hydropericardium hepatitis syndrome (HHS) in chickens and geese world widely. In this study, we firstly report the isolation of FAdV-C from ducks with HHS. The two isolates, designated as SDSX and SDJX, were separated from liver samples using 9-day-old SPF chicken embryos and could cause severe cytopathic effects in duck and chicken embryonic kidney cells. The entire ORF sequences of hexon gene of the two isolates were amplified, sequenced and analysed by restriction fragment length polymorphism. Phylogenetic analysis of loop 1 sequences of hexon gene of FAdVs revealed that the two isolates were closely related to FAdV-C isolates, which could cause HHS in chickens. Experimental infection indicated that the isolate was high pathogenicity to 20-day-old ducks. Our study shows that the recently emerged HHS in ducks was caused by FAdV-C and may possess a potential risk to other poultry flocks. © 2016 Blackwell Verlag GmbH.

  8. Ultrasonic Technique for Predicting Grittiness of Salted Duck Egg

    Science.gov (United States)

    Erawan, S.; Budiastra, I. W.; Subrata, I. D. M.

    2018-05-01

    Grittiness of egg yolk is a major factor in consumer acceptance of salted duck egg product. Commonly, the grittiness level is determined by the destructive method. Salted egg industries need a grading system that can judge the grittiness accurately and nondestructively. The purpose of this study was to develop a method for determining grittiness of salted duck eggs nondestructively based on ultrasonic method. This study used 100 samples of salted duck eggs with 7,10,14 and 21 days of salting age. Velocity and attenuation were measured by an ultrasonic system at frequency 50 kHz, followed by physicochemical properties measurement (hardness of egg yolks and salt content), and organoleptic test. Ultrasonic wave velocity in salted duck eggs ranged from 620.6 m/s to 1334.6 m/s, while the coefficient of attenuation value ranged from – 0.76 dB/m to -0.51 dB/m. Yolk hardness was 2.68 N at 7 days to 5.54 N at 21 days of salting age. Salt content was 1.81 % at 7 days to 5.71 % at 21 days of salting age. Highest scores of organoleptic tests on salted duck eggs were 4.23 and 4.18 for 10 and 14 days of salting age, respectively. Discriminant function using ultrasonic velocity variables in minor and major diameter could predict grittiness with 95 % accuracy.

  9. Late Holocene extinction of Finsch's duck (Chenonetta finschi), an endemic, possibly flightless, New Zealand duck

    International Nuclear Information System (INIS)

    Holdaway, R.N.; Jones, M.D.; Beavan Athfield, N.R.

    2002-01-01

    Finsch's duck (Chenonetta finschi), an extinct, possibly flightless New Zealand endemic, was widely distributed and apparently abundant immediately before human settlement of New Zealand, but its bones have rarely been identified in archaeological sites. Its extinction has been variously attributed to habitat changes, predation by the introduced Pacific rat (Rattus exulans), and human predation. Discriminating between possible causes of its extinction hinges on determining the relative timing of phases of the extinction process and the arrival of rats and humans. Methodological problems of determining the time of extinction of fossil species are reviewed. Bayesian statistical analysis of a series of accelerator mass spectrometry 14 C ages on gelatin from Finsch's duck bones from non-cultural deposits suggests that the species began to decline before widespread Polynesian settlement and that it was much reduced in range and numbers by the time extensive human predation and habitat alteration began. Possible causes of its extinction after Polynesian settlement are discussed. (author). 90 refs., 6 figs., 3 tabs

  10. Impacts of winter NPO on subsequent winter ENSO: sensitivity to the definition of NPO index

    Science.gov (United States)

    Chen, Shangfeng; Wu, Renguang

    2018-01-01

    This study investigates the linkage between boreal winter North Pacific Oscillation (NPO) and subsequent winter El Niño-Southern Oscillation (ENSO) based on seven different NPO indices. Results show that the influence of winter NPO on the subsequent winter El Niño is sensitive to how the NPO is defined. A significant NPO-El Niño connection is obtained when the NPO-related anomalous cyclone over the subtropical North Pacific extends to near-equatorial regions. The anomalous cyclone induces warm sea surface temperature (SST) anomalies through modulating surface heat fluxes. These warm SST anomalies are able to maintain into the following spring and summer through an air-sea coupled process and in turn induce significant westerly wind anomalies over the tropical western Pacific. In contrast, the NPO-El Niño relationship is unclear when the NPO-related anomalous cyclone over the subtropical North Pacific is confined to off-equatorial regions and cannot induce significant warm SST anomalies over the subtropical North Pacific. The present study suggests that definitions of NPO should be taken into account when using NPO to predict ENSO. In particular, we recommend defining the NPO index based on the empirical orthogonal function technique over appropriate region that does not extend too far north.

  11. Live Attenuated Vaccine based on Duck Enteritis Virus against Duck Hepatitis A Virus Types 1 and 3

    Directory of Open Access Journals (Sweden)

    Zhong Zou

    2016-10-01

    Full Text Available As causative agents of duck viral hepatitis, duck hepatitis A virus type 1 (DHAV-1 and type 3 (DHAV-3 causes significant economic losses in the duck industry. However, a licensed commercial vaccine that simultaneously controls both pathogens is currently unavailable. Here, we generated DEV recombinants (rC-KCE-2VP1 containing both VP1 from DHAV-1 (VP1/DHAV-1 and VP1 from DHAV-3 (VP1/DHAV-3 between UL27 and UL26. A self-cleaving 2A-element of FMDV was inserted between the two different types of VP1, allowing production of both proteins from a single open reading frame. Immunofluorescence and Western blot analysis results demonstrated that both VP1 proteins were robustly expressed in rC-KCE-2VP1-infected chicken embryo fibroblasts. Ducks that received a single dose of rC-KCE-2VP1 showed potent humoral and cellular immune responses and were completely protected against challenges of both pathogenic DHAV-1 and DHAV-3 strains. The protection was rapid, achieved as early as three days after vaccination. Moreover, viral replication was fully blocked in vaccinated ducks as early as one week post-vaccination. These results demonstrated, for the first time, that recombinant rC-KCE-2VP1 is potential fast-acting vaccine against DHAV-1 and DHAV-3.

  12. The preliminary study on peculiar flavor from irradiated dried duck

    International Nuclear Information System (INIS)

    Li Zongju; Chen Zongdao; Xu Denyi

    1992-01-01

    Peculiar flavor may be induced from irradiative preservation of meat with higher dose. The study on the irradiation of dried duck indicated that peculiar flavor is produced by a threshold of 1.5 kGy and intensifies with the increase of dose. The flavor primarily comes from muscle of dried duck especially from its water soluble protein. With the increase of dose, volatile carbonyl compounds, amines and sulfur compounds increased significantly. Paper chromatography analysis shows that two new volatile carbonyl compounds (R f =0.23 and 0.28) and a new volatile amine-propamine are induced by irradiation. This compounds may be the source of peculiar flavor in irradiated dried duck

  13. The preliminary study on peculiar flavor from irradiated dried duck

    Energy Technology Data Exchange (ETDEWEB)

    Zongju, Li; Zongdao, Chen; Denyi, Xu [Southwest Agricultural Univ., Chongqing, SC (China)

    1992-11-01

    Peculiar flavor may be induced from irradiative preservation of meat with higher dose. The study on the irradiation of dried duck indicated that peculiar flavor is produced by a threshold of 1.5 kGy and intensifies with the increase of dose. The flavor primarily comes from muscle of dried duck especially from its water soluble protein. With the increase of dose, volatile carbonyl compounds, amines and sulfur compounds increased significantly. Paper chromatography analysis shows that two new volatile carbonyl compounds (R[sub f] =0.23 and 0.28) and a new volatile amine-propamine are induced by irradiation. This compounds may be the source of peculiar flavor in irradiated dried duck.

  14. Employment and winter construction

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Larsen, Jacob Norvig

    2011-01-01

    Reduced seasonal building activity in the construction sector is often assumed to be related to hard winter conditions for building activities and poor working conditions for construction workers, resulting in higher costs and poor quality of building products, particularly in the northern hemisp...... of contracts for workers is more likely to explain differences in seasonal activity than climatic or technological factors....

  15. Titan's Emergence from Winter

    Science.gov (United States)

    Flasar, F. Michael; Achterberg, Richard; Jennings, Donald; Schinder, Paul

    2011-01-01

    We summarize the changes in Titans thermal structure derived from Cassini CIRS and radio-occultation data during the transition from winter to early spring. Titan's surface, and middle atmosphere show noticeable seasonal change, whereas that in most of the troposphere is mated. This can be understood in terms of the relatively small radiative relaxation time in the middle atmosphere and much larger time scale in the troposphere. The surface exhibits seasonal change because the heat capacity in an annual skin depth is much smaller than that in the lowest scale height of the troposphere. Surface temperatures rise 1 K at raid and high latitudes in the winter northern hemisphere and cool in the southern hemisphere. Changes in in the middle atmosphere are more complicated. Temperatures in the middle stratosphere (approximately 1 mbar) increase by a few kelvin at mid northern latitudes, but those at high latitudes first increase as that region moves out of winter shadow, and then decrease. This probably results from the combined effect of increased solar heating as the suit moves higher in the sky and the decreased adiabatic warming as the sinking motions associated with the cross-equatorial meridional cell weaken. Consistent with this interpretation, the warm temperatures observed higher up at the winter polar stratopause cool significantly.

  16. Development of an indirect ELISA with epitope on nonstructural protein of Muscovy duck parvovirus for differentiating between infected and vaccinated Muscovy ducks.

    Science.gov (United States)

    Yan, B; Ma, J-Z; Yu, T-F; Shao, S-L; Li, M; Fan, X-D

    2014-12-01

    The aim of this study was to develop an indirect enzyme-linked immunosorbent assay (i-ELISA) based on epitope AA503-509 (RANEPKE), which is on nonstructural protein of Muscovy duck parvovirus (MDPV). Sera (100) from negative and vaccinated Muscovy ducks were compared with infected sera (240) to establish the cut-off value of this i-ELISA. There was a significant difference between the positive and negative populations (P ducks from Muscovy ducks vaccinated with inactivated virus. In this study, we developed an i-ELISA based on epitope AA503-509 (RANEPKE), which is on nonstructural protein of MDPV. This i-ELISA could be used as a diagnostic tool for differentiating infected Muscovy ducks from Muscovy ducks vaccinated with inactivated virus. © 2014 The Society for Applied Microbiology.

  17. Modelling the distribution of domestic ducks in Monsoon Asia

    Science.gov (United States)

    Van Bockel, Thomas P.; Prosser, Diann; Franceschini, Gianluca; Biradar, Chandra; Wint, William; Robinson, Tim; Gilbert, Marius

    2011-01-01

    Domestic ducks are considered to be an important reservoir of highly pathogenic avian influenza (HPAI), as shown by a number of geospatial studies in which they have been identified as a significant risk factor associated with disease presence. Despite their importance in HPAI epidemiology, their large-scale distribution in Monsoon Asia is poorly understood. In this study, we created a spatial database of domestic duck census data in Asia and used it to train statistical distribution models for domestic duck distributions at a spatial resolution of 1km. The method was based on a modelling framework used by the Food and Agriculture Organisation to produce the Gridded Livestock of the World (GLW) database, and relies on stratified regression models between domestic duck densities and a set of agro-ecological explanatory variables. We evaluated different ways of stratifying the analysis and of combining the prediction to optimize the goodness of fit of the predictions. We found that domestic duck density could be predicted with reasonable accuracy (mean RMSE and correlation coefficient between log-transformed observed and predicted densities being 0.58 and 0.80, respectively), using a stratification based on livestock production systems. We tested the use of artificially degraded data on duck distributions in Thailand and Vietnam as training data, and compared the modelled outputs with the original high-resolution data. This showed, for these two countries at least, that these approaches could be used to accurately disaggregate provincial level (administrative level 1) statistical data to provide high resolution model distributions.

  18. Reciprocal crosses between Alabio and Mojosari ducks : early egg production

    Directory of Open Access Journals (Sweden)

    L.H Prasetyo

    2000-12-01

    Full Text Available alternative to increasing productivity and production efficiency. Crossbreeding has been used widely for increasing productivity, and in this experiment Alabio and Mojosari ducks were crossed reciprocally in order to evaluate their egg production and egg quality, when compared to their parental breeds. Four genotypes AA, AM, MA and MM were compared and each consisted of 50 layer ducks. Each animal was kept in individual cage, and individual egg production and egg quality were recorded. They were given layer feed containing 20% crude protein and 3000 kcal/kg metabolisable energy. Results showed that the crossbred ducks (AM and MA laid eggs earlier than their parental breeds (AA and MM, and MA laid earlier than AM. The weight of first eggs of the crossbreeds did not differ significantly, AM was the same as MM and MA the same as AA. For the body weight at first lay, MA and AM weighed in between their parental breeds, AA was the heaviest and then followed by MA, AM and MM. For the 3-month egg production, MA ducks laid significantly more egg than the other 3 genotypes, and this is related to the age of first lay being the earliest. In terms of egg quality such as egg weight, yolk color, weight and thickness of shell, weight of the white and HU value, the crossbred ducks showed quality in between AA and MM. The AM ducks tended to be closer to MM and MA closer to AA, and this shows a strong influence of maternal effects. The average level of heterosis for weight of first egg is 2.41% and for 3-month egg production is 2.1%, but for MA cross the heterosis level is 11.69% for egg production. The overall results showed that crossbreeds between Alabio and Mojosari have the potential in improving production traits in the effort to increase productivity and production efficiency.

  19. An empirical evaluation of landscape energetic models: Mallard and American black duck space use during the non-breeding period

    Science.gov (United States)

    Beatty, William S.; Webb, Elisabeth B.; Kesler, Dylan C.; Naylor, Luke W.; Raedeke, Andrew H.; Humburg, Dale D.; Coluccy, John M.; Soulliere, G.

    2015-01-01

    Bird conservation Joint Ventures are collaborative partnerships between public agencies and private organizations that facilitate habitat management to support waterfowl and other bird populations. A subset of Joint Ventures has developed energetic carrying capacity models (ECCs) to translate regional waterfowl population goals into habitat objectives during the non-breeding period. Energetic carrying capacity models consider food biomass, metabolism, and available habitat to estimate waterfowl carrying capacity within an area. To evaluate Joint Venture ECCs in the context of waterfowl space use, we monitored 33 female mallards (Anas platyrhynchos) and 55 female American black ducks (A. rubripes) using global positioning system satellite telemetry in the central and eastern United States. To quantify space use, we measured first-passage time (FPT: time required for an individual to transit across a circle of a given radius) at biologically relevant spatial scales for mallards (3.46 km) and American black ducks (2.30 km) during the non-breeding period, which included autumn migration, winter, and spring migration. We developed a series of models to predict FPT using Joint Venture ECCs and compared them to a biological null model that quantified habitat composition and a statistical null model, which included intercept and random terms. Energetic carrying capacity models predicted mallard space use more efficiently during autumn and spring migrations, but the statistical null was the top model for winter. For American black ducks, ECCs did not improve predictions of space use; the biological null was top ranked for winter and the statistical null was top ranked for spring migration. Thus, ECCs provided limited insight into predicting waterfowl space use during the non-breeding season. Refined estimates of spatial and temporal variation in food abundance, habitat conditions, and anthropogenic disturbance will likely improve ECCs and benefit conservation planners

  20. Transfection of embryonated Muscovy duck eggs with a recombinant plasmid is suitable for rescue of infectious Muscovy duck parvovirus.

    Science.gov (United States)

    Wang, Jianye; Huang, Yu; Ling, Jueyi; Wang, Zhixiang; Zhu, Guoqiang

    2017-12-01

    For members of the family Parvoviridae, rescue of infectious virus from recombinant plasmid is usually done in cultured cells. In this study, the whole genome of the pathogenic Muscovy duck parvovirus (MDPV) strain YY was cloned into the pBluescript II (SK) vector, generating recombinant plasmid pYY. With the aid of a transfection reagent, pYY plasmid was inoculated into 11-day-old embryonated Muscovy duck eggs via the chorioallantoic membrane route, resulting in the successful rescue of infectious virus and death of the embryos. The rescued virus exhibited pathogenicity in Muscovy ducklings similar to that of its parental strain, as evaluated based on the mortality rate. The results demonstrate that plasmid transfection in embryonated Muscovy duck eggs is a convenient and efficacious method for rescue of infectious MDPV in comparison to transfection of primary cells, which is somewhat time-consuming and laborious.

  1. Genetic Diversity Analysis of South and East Asian Duck Populations Using Highly Polymorphic Microsatellite Markers

    Directory of Open Access Journals (Sweden)

    Dongwon Seo

    2016-04-01

    Full Text Available Native duck populations have lower productivity, and have not been developed as much as commercials duck breeds. However, native ducks have more importance in terms of genetic diversity and potentially valuable economic traits. For this reason, population discriminable genetic markers are needed for conservation and development of native ducks. In this study, 24 highly polymorphic microsatellite (MS markers were investigated using commercial ducks and native East and South Asian ducks. The average polymorphic information content (PIC value for all MS markers was 0.584, indicating high discrimination power. All populations were discriminated using 14 highly polymorphic MS markers by genetic distance and phylogenetic analysis. The results indicated that there were close genetic relationships among populations. In the structure analysis, East Asian ducks shared more haplotypes with commercial ducks than South Asian ducks, and they had more independent haplotypes than others did. These results will provide useful information for genetic diversity studies in ducks and for the development of duck traceability systems in the market.

  2. No evidence that migratory geese disperse avian influenza viruses from breeding to wintering ground.

    Directory of Open Access Journals (Sweden)

    Shenglai Yin

    Full Text Available Low pathogenic avian influenza virus can mutate to a highly pathogenic strain that causes severe clinical signs in birds and humans. Migratory waterfowl, especially ducks, are considered the main hosts of low pathogenic avian influenza virus, but the role of geese in dispersing the virus over long-distances is still unclear. We collected throat and cloaca samples from three goose species, Bean goose (Anser fabalis, Barnacle goose (Branta leucopsis and Greater white-fronted goose (Anser albifrons, from their breeding grounds, spring stopover sites, and wintering grounds. We tested if the geese were infected with low pathogenic avian influenza virus outside of their wintering grounds, and analysed the spatial and temporal patterns of infection prevalence on their wintering grounds. Our results show that geese were not infected before their arrival on wintering grounds. Barnacle geese and Greater white-fronted geese had low prevalence of infection just after their arrival on wintering grounds in the Netherlands, but the prevalence increased in successive months, and peaked after December. This suggests that migratory geese are exposed to the virus after their arrival on wintering grounds, indicating that migratory geese might not disperse low pathogenic avian influenza virus during autumn migration.

  3. Prototype of A/Duck/Sukoharjo/Bbvw-1428-9/2012 subtipe H5N1 clade 2.3.2 as vaccine on local duck

    Directory of Open Access Journals (Sweden)

    Risa Indriani

    2014-06-01

    Full Text Available A/Duck/Sukoharjo/Bbvw-1428-9/2012 virus subtipe H5N1 clade 2.3.2 as seed vaccine on local duck. AI H5N1 clade 2.3.2 vaccine containing 256 HAU per dose was formulated using adjuvant ISA 71VG Montanide ™. Six groups of one day old local duck were used in this study. Three groups (10 ducks per group were vaccinated and 3 groups (9 duck per group were served control. Vaccination was conducted when the duck were three weeks old of age using single dose. Three weeks after vaccination when the duck were challenged either with HPAI H5N1 clade 2.3.2, or HPAI H5N1 clade 2.1.3 virus at dose 106 EID50/ 0.1 ml by drops intranasaly. Result showed that vaccination produced 100% protection compared to unvaccinated ducks againt HPAI subtipe H5N1 clade 2.3.2, and 100% protection againt HPAI H5N1 clade 2.1.3 (A/ck/wj/Subang-29/2007 and A/ck/wj/Smi-Part/2006, while unvaccinated ducks showed virus shedding on day 3 post infection.

  4. RNA-seq comparative analysis of Peking ducks spleen gene expression 24 h post-infected with duck plague virulent or attenuated virus.

    Science.gov (United States)

    Liu, Tian; Cheng, Anchun; Wang, Mingshu; Jia, Renyong; Yang, Qiao; Wu, Ying; Sun, Kunfeng; Zhu, Dekang; Chen, Shun; Liu, Mafeng; Zhao, XinXin; Chen, Xiaoyue

    2017-09-13

    Duck plague virus (DPV), a member of alphaherpesvirus sub-family, can cause significant economic losses on duck farms in China. DPV Chinese virulent strain (CHv) is highly pathogenic and could induce massive ducks death. Attenuated DPV vaccines (CHa) have been put into service against duck plague with billions of doses in China each year. Researches on DPV have been development for many years, however, a comprehensive understanding of molecular mechanisms underlying pathogenicity of CHv strain and protection of CHa strain to ducks is still blank. In present study, we performed RNA-seq technology to analyze transcriptome profiling of duck spleens for the first time to identify differentially expressed genes (DEGs) associated with the infection of CHv and CHa at 24 h. Comparison of gene expression with mock ducks revealed 748 DEGs and 484 DEGs after CHv and CHa infection, respectively. Gene pathway analysis of DEGs highlighted valuable biological processes involved in host immune response, cell apoptosis and viral invasion. Genes expressed in those pathways were different in CHv infected duck spleens and CHa vaccinated duck spleens. The results may provide valuable information for us to explore the reasons of pathogenicity caused by CHv strain and protection activated by CHa strain.

  5. The phenotypic diversity and fruit characterization of winter squash ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Jan 11, 2010 ... collected from different provinces of the Black Sea region in 2006 and 2007 and phenotypic ... Picture of the diversity fruit size, shape and color for Cucurbita maxima ... Fruit traits used winter squash (C. maxima Duch) population characterization. S/N ..... Group J: There were a total of 18 populations in this.

  6. Investigation of the relationship between permafrost distribution in NW Europe and extensive winter sea-ice cover in the North Atlantic Ocean during the cold phases of the Last Glaciation.

    NARCIS (Netherlands)

    Renssen, H.; Vandenberghe, J.

    2003-01-01

    Atmospheric model simulations with different extents of sea-ice are compared with reconstructed European mean annual temperatures derived from permafrost indicators. Analysis of the results suggest that during cold phases of the Last Glacial, the southern margin of permafrost in western Europe was

  7. Editorial - The winter Atomiades

    CERN Multimedia

    Staff Association

    2011-01-01

    As we wrote in our previous editorial, the Staff Association gives direct support to sports events, such as the Atomiades, a section of the Association of Sports Communities of European Research Institutes, which brings together sportsmen and women from 38 European research centres in 13 countries (Austria, Belgium, Czech Republic, United Kingdom, Finland, France, Germany, Hungary, Italy, Luxemburg, the Netherlands, Russia, and Switzerland). The summer Atomiades take place between the months of June and September every three years. Thirteen such events have taken place since 1973, the last one in June 2009 in Berlin. As far as the winter Atomiades are concerned, also organized every three years, and alternating with the summer Atomiades, there have been eleven since 1981, the last one at the end of January this year in neighbouring France. The following article tells the wonderful adventure of the CERN staff who took part in this event. A positive outcome for CERN skiers at the winter Atomiades The 11t...

  8. Winter is losing its cool

    Science.gov (United States)

    Feng, S.

    2017-12-01

    Winter seasons have significant societal impacts across all sectors ranging from direct human health to ecosystems, transportation, and recreation. This study quantifies the severity of winter and its spatial-temporal variations using a newly developed winter severity index and daily temperature, snowfall and snow depth. The winter severity and the number of extreme winter days are decreasing across the global terrestrial areas during 1901-2015 except the southeast United States and isolated regions in the Southern Hemisphere. These changes are dominated by winter warming, while the changes in daily snowfall and snow depth played a secondary role. The simulations of multiple CMIP5 climate models can well capture the spatial and temporal variations of the observed changes in winter severity and extremes during 1951-2005. The models are consistent in projecting a future milder winter under various scenarios. The winter severity is projected to decrease 60-80% in the middle-latitude Northern Hemisphere under the business-as-usual scenario. The winter arrives later, ends earlier and the length of winter season will be notably shorter. The changes in harsh winter in the polar regions are weak, mainly because the warming leads to more snowfall in the high latitudes.

  9. The liability of some haematological parameters in chickens and ducks

    African Journals Online (AJOL)

    The liability of some haematological parameters in chickens and ducks. E.M. Smith, J Hattingh. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

  10. Fish and harlequin ducks compete on breeding streams

    NARCIS (Netherlands)

    LeBourdais, S.V.; Ydenberg, R.C.; Esler, D.

    2009-01-01

    We investigated interactions among harlequin ducks (Histrionicus histrionicus ( L., 1758)), fish, and their shared aquatic insect prey. We measured flow variability, benthic aquatic prey abundance, fish presence, and breeding density of harlequins on eight rivers in the Southern Coast Mountain Range

  11. 78 FR 10201 - Proposed Information Collection; Electronic Duck Stamp Program

    Science.gov (United States)

    2013-02-13

    ..., Interior. ACTION: Notice; request for comments. SUMMARY: We (U.S. Fish and Wildlife Service) will ask the... refuges where admission is charged. Duck Stamps and products that bear stamp images are also popular... fee the State will charge for issuance of an electronic stamp. Description of the process the State...

  12. Estimation of L-threonine requirements for Longyan laying ducks

    Directory of Open Access Journals (Sweden)

    A. M. Fouad

    2017-02-01

    Full Text Available Objective A study was conducted to test six threonine (Thr levels (0.39%, 0.44%, 0.49%, 0.54%, 0.59%, and 0.64% to estimate the optimal dietary Thr requirements for Longyan laying ducks from 17 to 45 wk of age. Methods Nine hundred Longyan ducks aged 17 wk were assigned randomly to the six dietary treatments, where each treatment comprised six replicate pens with 25 ducks per pen. Results Increasing the Thr level enhanced egg production, egg weight, egg mass, and the feed conversion ratio (FCR (linearly or quadratically; p<0.05. The Haugh unit score, yolk color, albumen height, and the weight, percentage, thickness, and breaking strength of the eggshell did not response to increases in the Thr levels, but the albumen weight and its proportion increased significantly (p<0.05, whereas the yolk weight and its proportion decreased significantly as the Thr levels increased. Conclusion According to a regression model, the optimal Thr requirement for egg production, egg mass, and FCR in Longyan ducks is 0.57%, while 0.58% is the optimal level for egg weight from 17 to 45 wk of age.

  13. Karyotype analysis in Machaerium lunatum (Linn. f.) Ducke ...

    African Journals Online (AJOL)

    ADOWIE PERE

    2017-12-11

    Dec 11, 2017 ... Ducke (syn. Drepanocarpus lunatus (Linn. f.) G.F.W. Mey) belongs to the family Fabaceae-Papilionaceae. (Hutchinson and Dalziel 1954). It has about 130 species distributed from Mexico to Argentina which are difficult to delimit taxonomically (Rudd 1987) and 150 species distributed from Mexico to South.

  14. Genetic Divergence in Ducks for Economic Traits | Kalita | Animal ...

    African Journals Online (AJOL)

    D2 Statistics was used to identify the genetic divergence in 4 groups of duck, namely Khaki Campbell (KC), Desi (D), Khaki Campbell x Desi (KC x D) and Desi x Khaki Campbell (D x KC) reared under rural conditions at the Siphajar, Darrang District, Assam, India. The study showed that both Khaki Campbell and Desi or ...

  15. The evaluation of domestic ducks as potential reservoir of avian ...

    African Journals Online (AJOL)

    The evaluation of domestic ducks as potential reservoir of avian influenza virus in post HPAI H5N1 outbreak area, Sunyani Municipality, Brong Ahafo Region of Ghana. Vitus Burimuah, W.K. Ampofo, B Awumbila, N Yebuah, B.O. Emikpe, W Tasiame, R.D. Folitse ...

  16. Carcass Characteristics and Meat Quality of Korean Native Ducks and Commercial Meat-type Ducks Raised under Same Feeding and Rearing Conditions

    Directory of Open Access Journals (Sweden)

    H. J. Kwon

    2014-11-01

    Full Text Available This study was conducted to compare carcass characteristics and physico-chemical meat quality in two different genotype ducks raised under identical feeding and rearing conditions. A total of ninety 1-d-old Korean native ducks (KND, n = 45 and commercial meat-type ducks (Grimaud, n = 45 were fed same experimental diets during 56 d and 42 d, respectively to obtain similar slaughter weights. The experimental diet for starter period contained 20% crude protein (CP and 2,900 kcal nitrogen corrected true metabolizable energy (TMEn/kg of diet and that for grower period contained 17% CP and 3,050 TMEn/kg of diet. Average daily gain and feed efficiency of KND were inferior to those of commercial meat-type ducks (p<0.05. Carcass weight was not different between two genetically different ducks, but carcass yield of KND was significantly higher (p<0.05 than that of commercial meat-type ducks. There were no significant differences in cooking loss and pH of breast meat between two genetically different ducks, but water holding capacity of KND was significantly higher than that of commercial meat-type ducks. The linoleic acid and total polyunsaturated fatty acid of breast meat from KND were significantly higher (p<0.05 than the corresponding part from commercial meat-type ducks. Significant differences were detected in water holding capacity and the content of linoleic acid and polyunsaturated fatty acid, which were significantly higher in KND, whereas growth performance tended to be superior in commercial ducks. At the market weight, the meat from KND was judged to have better qualities with regard to higher water holding capacity and greater content of polyunsaturated fatty acid compare with meat from commercial meat-type duck.

  17. Evaluation of duck efficiency as a biocontrol agent on weed density and diversity in rice-duck farming (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    M. Mohammadi

    2016-05-01

    Full Text Available In order to evaluate the effect of ducks number on weeds diversity and density in paddy fields, an experiment was conducted at Sari Agricultural Sciences and Natural Resource University during growing season of 2011-2012. Experiment was arranged in split plot based on complete randomized block design with four replications. Main factors were duck number at three levels (consisting of control, 400 and 800 ducks.ha-1 and sub plots were three contrast cultivars (including Tarom as a traditional, and Shirodi and Ghaem as improved cultivars. Results of ANOVA showed highly significant differences between ducks, cultivars and ducks × cultivar interaction in terms of weeds density including nutsedge (Cyperus spp. L., common Water-plantain (Alisma plantago-aquatica L., barnyard grass (Echinochloa crus-galli L., duckweed (Lemna minor L., azolla (Azolla pinata R.Br. and paddy yield. Accordingly, the lowest weed density and diversity were recorded at 800 and 400 ducks.ha-1, respectively. Among rice cultivars Tarom and Ghaem had the minimum and the maximum weeds density and diversity. The highest nutsedge density (67 plant.m-2 was related to Ghaem cultivar in control (without duck plots as much as 97% higher than 800 ducks.ha-1. Maximum paddy yield was observed in 800 ducks.ha-1 in Shirodi (5.3 t.ha-1, Ghaem (4.3 t.ha-1 and Tarom (3.6 t.ha-1 as much as 23, 7 and 20% higher than those cultivars in 400 ducks.ha-1, respectively. Finally, in the current research conditions using 800 ducks.ha-1and Tarom cultivar resulted the best performance because of the lowest weed diversity and density as compared to other treatments.

  18. Effects of El Nino Modoki on winter precipitation in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do-Woo [Korea Meteorological Administration, National Institute of Meteorological Research, Seoul (Korea, Republic of); Choi, Ki-Seon [Korea Meteorological Administration, National Typhoon Center, Jeju (Korea, Republic of); Byun, Hi-Ryong [Pukyong National University, Department of Environmental Atmospheric Sciences, Nam-gu, Busan (Korea, Republic of)

    2012-04-15

    This study compares the impacts of El Nino Modoki and El Nino on precipitation over Korea during the boreal winters from 1954 to 2009. Precipitation in Korea tends to be equal to or greater than the normal level during an El Nino Modoki winter, whereas there is no significant change during an El Nino winter. Greater than normal precipitation during El Nino Modoki was also found over the lower reaches of the Yangtze River, China and much of southern Japan. The latitudes of these regions are 5-10 further north than in southern China, where precipitation increases during El Nino. The following two anomalous atmospheric circulations were found to be causes that led to different precipitation distributions over East Asia. First, an atmospheric wave train in the lower troposphere, which propagated from the central tropical Pacific (cyclonic) through the southern Philippine Sea (anticyclonic) to East Asia (cyclonic), reached the southern China and northern Philippine Sea during El Nino, whereas it reached Korea and southern Japan during El Nino Modoki. Second, an anomalous local meridional circulation, which consists of air sinking in the tropics, flowing poleward in the lower troposphere, and rising in the subtropics, developed between the southern Philippine Sea and northern Philippine Sea during El Nino. During El Nino Modoki, however, this circulation expanded further to the north and was formed between the southern Philippine Sea and regions of Korea and southern Japan. (orig.)

  19. Wetland dynamics influence mid-continent duck recruitment

    Science.gov (United States)

    Anteau, Michael J.; Pearse, Aaron T.; Szymankski, Michael L.

    2013-01-01

    Recruitment is a key factor influencing duck population dynamics. Understanding what regulates recruitment of ducks is a prerequisite to informed habitat and harvest management. Quantity of May ponds (MP) has been linked to recruitment and population size (Kaminski and Gluesing 1987, Raveling and Heitmeyer 1989). However, wetland productivity (quality) is driven by inter-annual hydrological fluctuations. Periodic drying of wetlands due to wet-dry climate cycles releases nutrients and increases invertebrate populations when wet conditions return (Euliss et al. 1999). Wetlands may also become wet or dry within a breeding season. Accordingly, inter-annual and intra-seasonal hydrologic variation potentially influence duck recruitment. Here, we examined influences of wetland quantity, quality, and intra-seasonal dynamics on recruitment of ducks. We indexed duck recruitment by vulnerability-corrected age ratios (juveniles/adult females) for mid-continent Gadwall (Anas strepera). We chose Gadwall because the majority of the continental population breeds in the Prairie Pothole Region (PPR), where annual estimates of MP exist since 1974. We indexed wetland quality by calculating change in MP (?MP) over the past two years (?MP = 0.6[MPt – MPt-1] + 0.4[MPt – MPt-2]). We indexed intra-seasonal change in number of ponds by dividing the PPR mean standardized precipitation index for July by MP (hereafter summer index). MP and ?MP were positively correlated (r = 0.65); therefore, we calculated residual ?MP (?MPr) with a simple linear regression using MP, creating orthogonal variables. Finally, we conducted a multiple regression to examine how MP, ?MPr, and summer index explained variation in recruitment of Gadwall from 1976–2010. Our model explained 67% of the variation in mid-continent Gadwall recruitment and all three hydrologic indices were positively correlated with recruitment (Figure 1). Type II semi-partial R2 estimates indicated that MP accounted for 41%, ?MPr

  20. Indirect risk effects reduce feeding efficiency of ducks during spring.

    Science.gov (United States)

    Behney, Adam C; O'Shaughnessy, Ryan; Eichholz, Michael W; Stafford, Joshua D

    2018-01-01

    Indirect risk effects of predators on prey behavior can have more of an impact on prey populations than direct consumptive effects. Predation risk can elicit more vigilance behavior in prey, reducing the amount of time available for other activities, such as foraging, which could potentially reduce foraging efficiency. Understanding the conditions associated with predation risk and the specific effects predation risk have on prey behavior is important because it has direct influences on the profitability of food items found under various conditions and states of the forager. The goals of this study were to assess how ducks perceived predation risk in various habitat types and how strongly perceived risk versus energetic demand affected foraging behavior. We manipulated food abundance in different wetland types in Illinois, USA to reduce confounding between food abundance and vegetation structure. We conducted focal-animal behavioral samples on five duck species in treatment and control plots and used generalized linear mixed-effects models to compare the effects of vegetation structure versus other factors on the intensity with which ducks fed and the duration of feeding stints. Mallards fed more intensively and, along with blue-winged teal, used longer feeding stints in open habitats, consistent with the hypothesis that limited visibility was perceived to have a greater predation risk than unlimited visibility. The species temporally nearest to nesting, wood ducks, were willing to take more risks for a greater food reward, consistent with an increase in a marginal value of energy as they approached nesting. Our results indicate that some duck species value energy differently based on the surrounding vegetation structure and density. Furthermore, increases in the marginal value of energy can be more influential than perceived risk in shaping foraging behavior patterns. Based on these findings, we conclude that the value of various food items is not solely

  1. Movement analysis of free-grazing domestic ducks in Poyang Lake, China: a disease connection.

    Science.gov (United States)

    Prosser, Diann J; Palm, Eric C; Takekawa, John Y; Zhao, Delong; Xiao, Xiangming; Li, Peng; Liu, Ying; Newman, Scott H

    2016-01-01

    Previous work suggests domestic poultry are important contributors to the emergence and transmission of highly pathogenic avian influenza throughout Asia. In Poyang Lake, China, domestic duck production cycles are synchronized with arrival and departure of thousands of migratory wild birds in the area. During these periods, high densities of juvenile domestic ducks are in close proximity to migratory wild ducks, increasing the potential for the virus to be transmitted and subsequently disseminated via migration. In this paper, we use GPS dataloggers and dynamic Brownian bridge models to describe movements and habitat use of free-grazing domestic ducks in the Poyang Lake basin and identify specific areas that may have the highest risk of H5N1 transmission between domestic and wild birds. Specifically, we determine relative use by free-grazing domestic ducks of natural wetlands, which are the most heavily used areas by migratory wild ducks, and of rice paddies, which provide habitat for resident wild ducks and lower densities of migratory wild ducks. To our knowledge, this is the first movement study on domestic ducks, and our data show potential for free-grazing domestic ducks from farms located near natural wetlands to come in contact with wild waterfowl, thereby increasing the risk for disease transmission. This study provides an example of the importance of movement ecology studies in understanding dynamics such as disease transmission on a complicated landscape.

  2. Movement analysis of free-grazing domestic ducks in Poyang Lake, China: A disease connection

    Science.gov (United States)

    Prosser, Diann J.; Palm, Eric C.; Takekawa, John Y.; Zhao, Delong; Xiao, Xiangming; Li, Peng; Liu, Ying; Newman, Scott H.

    2015-01-01

    Previous work suggests domestic poultry are important contributors to the emergence and transmission of highly pathogenic avian influenza throughout Asia. In Poyang Lake, China, domestic duck production cycles are synchronized with arrival and departure of thousands of migratory wild birds in the area. During these periods, high densities of juvenile domestic ducks are in close proximity to migratory wild ducks, increasing the potential for the virus to be transmitted and subsequently disseminated via migration. In this paper, we use GPS dataloggers and dynamic Brownian bridge models to describe movements and habitat use of free-grazing domestic ducks in the Poyang Lake basin and identify specific areas that may have the highest risk of H5N1 transmission between domestic and wild birds. Specifically, we determine relative use by free-grazing domestic ducks of natural wetlands, which are the most heavily used areas by migratory wild ducks, and of rice paddies, which provide habitat for resident wild ducks and lower densities of migratory wild ducks. To our knowledge, this is the first movement study on domestic ducks, and our data show potential for free-grazing domestic ducks from farms located near natural wetlands to come in contact with wild waterfowl, thereby increasing the risk for disease transmission. This study provides an example of the importance of movement ecology studies in understanding dynamics such as disease transmission on a complicated landscape.

  3. Live weight and body measurements of male and female native ducks raised in different raising systems

    Directory of Open Access Journals (Sweden)

    Kadir Önk

    2018-05-01

    Full Text Available ABSTRACT The purpose of this study was to determine live weight and body measurements of male and female native ducks raised in different raising systems. One hundred and twenty native ducks (60 males, 60 females were used in the study. The ducks were raised in deep litter floor and cage systems. Live weight and body values were measured every two weeks, until they were 56 days old. Three-parameter logistic regression and Gompertz model were used to determine growth model of male and female ducks. Interactions of time-raising system and time-sex were statistically significant in terms of live weight. At the end of eight weeks, live weights of ducks raised in deep litter floor were higher than ducks raised in cage system. In addition, live weights of male ducks were higher than female ducks. Consequently, deep litter floor is more appropriate for live weight in native ducks. Accuracy rate of Three-parameter Logistic and Gompertz models for estimation of growth in ducks was between 0.91-0.95 and similar results were obtained from both models. The Gompertz model is appropriate for the data structure of this study because it contains fewer iterations than the Three-Parameter Logistic model.

  4. Who Is Spreading Avian Influenza in the Moving Duck Flock Farming Network of Indonesia?

    Directory of Open Access Journals (Sweden)

    Joerg Henning

    Full Text Available Duck populations are considered to be a reservoir of Highly pathogenic avian influenza (HPAI virus H5N1 in some agricultural production systems, as they are able to shed the virus for several days without clinical signs. Countries endemically affected with HPAI in Asia are characterised by production systems where ducks are fed on post-harvest spilled rice. During this scavenging process it is common for ducks to come into contact with other duck flocks or wild birds, thereby providing opportunities for virus spread. Effective risk management for HPAI has been significantly compromised by a limited understanding of management of moving duck flocks in these countries, despite of a small number of recent investigations. Here, for the first time, we described the management of moving duck flocks and the structure of the moving duck flock network in quantitative terms so that factors influencing the risk of HPAIV transmission can be identified. By following moving duck flock farmers over a period of 6 months in Java, Indonesia, we were able to describe the movement of flocks and to characterise the network of various types of actors associated with the production system. We used these data to estimate the basic reproductive number for HPAI virus spread. Our results suggest that focussing HPAI prevention measures on duck flocks alone will not be sufficient. Instead, the role of transporters of moving duck flocks, hatcheries and rice paddy owners, in the spread of the HPAI virus needs to be recognised.

  5. Survey for West Nile virus antibodies in wild ducks, 2004-06, USA

    Science.gov (United States)

    Hofmeister, Erik K.; Jankowski, Mark D.; Goldberg, Diana R.; Franson, J. Christian

    2016-01-01

    Detection of West Nile virus (WNV) in ducks has been reported in North America in isolated cases of mortality in wild waterbirds and following outbreaks in farmed ducks. Although the virus has been noted as an apparent incidental finding in several species of ducks, little is known about the prevalence of exposure or the outcome of infection with WNV in wild ducks in North America. From 2004–06, we collected sera from 1,406 wild-caught American Wigeon (Anas americana), Mallard (Anas platyrhynchos), and Northern Pintail (Anas acuta) ducks at national wildlife refuges (NWRs) in North Dakota and Wood Ducks (Aix sponsa) at NWRs in South Carolina and Tennessee. We measured the prevalence of previous exposure to WNV in these ducks by measuring WNV antibodies and evaluated variation in exposure among species, age, and year. Additionally, we evaluated the performance of a commercial antibody to wild bird immunoglobulin in duck species that varied in their phylogenetic relatedness to the bird species the antibody was directed against. As determined by a screening immunoassay and a confirmatory plaque reduction neutralization assay, the prevalence of WNV antibody was 10%. In light of experimental studies that show ducks to be relatively resistant to mortality caused by WNV, the antibody prevalence we detected suggests that wild ducks may be less-frequently exposed to WNV than expected for birds inhabiting wetlands where they may acquire infection from mosquitoes.

  6. Effects of Maillard reaction on flavor and safety of Chinese traditional food: roast duck.

    Science.gov (United States)

    Zhou, Yiming; Xie, Fan; Zhou, Xiaoli; Wang, Yuqiang; Tang, Wen; Xiao, Ying

    2016-04-01

    Roast duck is one kind of representative roast food whose flavor is mainly produced by the Maillard reaction. However, some potentially toxic compounds are generated in the thermal process and are a potential health risk. The aim of this work was to analyze the effects of the Maillard reaction on flavor and safety of a Chinese traditional food: roast duck. Ducks with different roasting times (0, 10, 20, 30, 40, 50 and 60 min) were analyzed. The 40 and 50 min roast ducks exhibited an acceptable degree of sensory attributes, but the 60 min roast duck showed the most abundant aroma compounds. Antioxidant activities were observed to increase with roasting, and the 60 min roast duck showed the highest antioxidant activities (1,1-diphenylpicryhydrazyl, 39.3 µmol Trolox g(-1) sample). The highest content of acrylamide (0.21 µg g(-1)) and 5-hydroxymethylfurfural (0.089 µg g(-1)) were detected in the 50 and 60 min roast duck extract, respectively. Furthermore, water extract from 60 min roast ducks manifested a higher lactose dehydrogenase release ratio (51.9%) and greatly increased cell apoptosis. The drastic Maillard reaction in duck induced by long roasting time could be advantageous for color, aroma and antioxidant activities in roast ducks, but might be not beneficial to health. © 2015 Society of Chemical Industry.

  7. Winter Frost and Fog

    Science.gov (United States)

    2005-01-01

    This somewhat oblique blue wide angle Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the 174 km (108 mi) diameter crater, Terby, and its vicinity in December 2004. Located north of Hellas, this region can be covered with seasonal frost and ground-hugging fog, even in the afternoon, despite being north of 30oS. The subtle, wavy pattern is a manifestation of fog. Location near: 28oS, 286oW Illumination from: upper left Season: Southern Winter

  8. The estimation of genetic distance and discriminant variables on breed of duck (Alabio, Bali, Khaki Campbell, Mojosari and Pegagan) by morphological analysis

    OpenAIRE

    B Brahmantiyo; L.H Prasetyo; A.R Setioko; R.H Mulyono

    2003-01-01

    A study on morphological body conformation of Alabio, Bali, Khaki Campbell, Mojosari and Pegagan ducks was carried out to determine the genetic distance and discriminant variables. This research was held in Research Institute for Animal Production, Ciawi, Bogor using 65 Alabio ducks, 40 Bali ducks, 36 Khaki Campbell ducks, 60 Mojosari ducks and 30 Pegagan ducks. Seven different body parts were measured, they were the length of femur, tibia, tarsometatarsus, the circumference of tarsometatarsu...

  9. Spreading Of Avian Flu On Duck And Its Impact On Social Economy: Lesson Learnt From Avian Flu Cases On Chicken

    OpenAIRE

    Nyak Ilham

    2013-01-01

    Bird flu disease that attacks duck dismissed the notion of duck immune to bird flu disease. Learning from the experience of bird flu disease that attacks poultry in the year of 2004-2005, necessary to measure the spread of disease prevention bird flu in ducks. This paper aims to describe the business and trade patterns of duck associated with the spread of avian influenza and predict the socio-economic impact of bird flu on duck farms in Indonesia. Duck rearing patterns mostly are in the e...

  10. Decontamination and winter conditions

    International Nuclear Information System (INIS)

    Quenild, C.; Tveten, U.

    1984-12-01

    The report deals with two decontamonation experiments under winter conditions. A snow-covered parking lot was contaminated, and the snow was subsequently removed using standard snow-moving equipment. The snow left behind was collected and the content of contaminant was determined. A non-radioactive contaminant was used. A decontamination factor exceeding 100 was obtained. Although the eksperimental conditions were close to ideal, it is reason to believe that extremely efficient removal of deposited materials on a snow surface is achivable. In another investigation, run-off from agricultural surface, contaminated while covered with snow, was measured A lycimeter was used in this experiment. A stable layer of ice and snow was allowed to form before contamination. The run-off water was collected at each thaw period until all snow and ice was gone. Cs-134 was used as contaminant. Roughly 30% of the Cs-134 with which the area was contaminated ran off with the melt water. Following a reactor accident situation, this would have given a corresponding reduction in the long term doses. Both of these experiments show that consequence calculation assumptions, as they are currently applied to large accident assessment, tend to overestimate the consequences resulting from accidents taking place under winter conditions

  11. Spirit's Winter Work Site

    Science.gov (United States)

    2006-01-01

    [figure removed for brevity, see original site] Annotated Version This portion of an image acquired by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment camera shows the Spirit rover's winter campaign site. Spirit was parked on a slope tilted 11 degrees to the north to maximize sunlight during the southern winter season. 'Tyrone' is an area where the rover's wheels disturbed light-toned soils. Remote sensing and in-situ analyses found the light-toned soil at Tyrone to be sulfate rich and hydrated. The original picture is catalogued as PSP_001513_1655_red and was taken on Sept. 29, 2006. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.

  12. Winter School Les Houches

    CERN Document Server

    Lannoo, Michel; Bastard, Gérald; Voos, Michel; Boccara, Nino

    1986-01-01

    The Winter School held in Les Houches on March 12-21, 1985 was devoted to Semiconductor Heterojunctions and Superlattices, a topic which is recognized as being now one of the most interesting and active fields in semiconductor physics. In fact, following the pioneering work of Esaki and Tsu in 1970, the study of these two-dimensional semiconductor heterostructures has developed rapidly, both from the point of view of basic physics and of applications. For instance, modulation-doped heterojunctions are nowadays currently used to investigate the quantum Hall effect and to make very fast transistors. This book contains the lectures presented at this Winter School, showing in particular that many aspects of semiconductor heterojunctions and super­ lattices were treated, extending from the fabrication of these two-dimensional systems to their basic properties and applications in micro-and opto-electron­ ics. Among the subjects which were covered, one can quote as examples: molecular beam epitaxy and metallorgani...

  13. Maternal transfer of dechloranes and their distribution among tissues in contaminated ducks.

    Science.gov (United States)

    Wu, Ping-Fan; Yu, Lian-Lian; Li, Long; Zhang, Yun; Li, Xing-Hong

    2016-05-01

    The tissue concentrations of dechlorane plus and its analogues were determined in ducks collected from several e-waste recycling villages of Taizhou, China. Compared with the published literature, the relatively high concentrations of these compounds were detected in ducks, indicating serious DP contamination. Since both the duck meat and eggs were important components for diet, this result reminded us of keeping a watchful eye on human dietary exposure to DP and its analogues in this study area. The wet-weight concentrations of DP and its analogues were significantly related to tissue lipid content (p ducks. On the basis of lipid adjustment, the significantly lower levels in brain than those in liver and blood, displayed the occurrence of liver sequestration and blood-brain barrier to DP and its analogues in the duck (p ducks. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Evaluation of a portable automated serum chemistry analyzer for field assessment of harlequin ducks, Histrionicus histrionicus

    Science.gov (United States)

    Stoskopf, Michael K.; Mulcahy, Daniel M.; Esler, Daniel N.

    2010-01-01

    A portable analytical chemistry analyzer was used to make field assessments of wild harlequin ducks (Histrionicus histrionicus) in association with telemetry studies of winter survival in Prince William Sound, Alaska. We compared serum chemistry results obtained on-site with results from a traditional laboratory. Particular attention was paid to serum glucose and potassium concentrations as potential indicators of high-risk surgical candidates based on evaluation of the field data. The median differential for glucose values ( = 8 2) between methods was 0.6 mmol/L (quartiles 0.3 and 0.9 mmol/L) with the median value higher when assayed on site. Analysis of potassium on site returned a median of 2.7 mmol/L ( = 8 8 ; quartiles 2.4 and 3.0 mmol/L). Serum potassium values were too low for quantitation by the traditional laboratory. Changes in several serum chemistry values following a three-day storm during the study support the value of on site evaluation of serum potassium to identify presurgical patients with increased anesthetic risk.

  15. Stable-isotope analysis of canvasback winter diet in upper Chesapeake Bay

    Science.gov (United States)

    Haramis, G.M.; Jorde, Dennis G.; Macko, S.A.; Walker, J.L.

    2001-01-01

    A major decline in submerged aquatic vegetation (SAV) in Chesapeake Bay has altered the diet of wintering Canvasbacks (Aythya valisineria) from historically plant to a combination of benthic animal foods, especially the ubiquitous Baltic clam (Macoma balthica), supplemented with anthropogenic corn (Zea mays). Because the isotopic signature of corn is readily discriminated from bay benthos, but not SAV, we used stable-isotope methodology to investigate the corn–SAV component of the winter diet of Canvasbacks. Feeding trials with penned Canvasbacks were conducted to establish turnover rates and fractionation end-point loci of δ13C and δ15N signatures of whole blood for individual ducks fed ad libitum diets of (1) Baltic clams, (2) Baltic clams and corn, and (3) tubers of wild celery (Vallisneria americana). Turnover time constants averaged 4.5 weeks, indicating that signatures of wild ducks would be representative of bay diets by late February. Isotopic signatures of wild Canvasbacks sampled in February fell on a continuum between end-point loci for the Baltic clam and the combination Baltic clam and corn diet. Although that finding verifies a clear dependence on corn–SAV for wintering Canvasbacks, it also reveals that not enough corn–SAV is available to establish ad libitum consumption for the 15,000+ Canvasbacks wintering in the upper bay. On the basis of mean δ13C signature of bay Canvasbacks (n = 59) and ingestion rates from feeding trials, we estimated that 258 kg corn per day would account for the observed δ13C enrichment and supply 18% of daily energetic needs for 15,000 Canvasbacks. That level of corn availability is so realistic that we conclude that SAV is likely of little dietary importance to Canvasbacks in that portion of the bay.

  16. Result of observation on winter lightning onto a wireless tower in a mountainous area along the Sea of Japan. Nihonkai engan no sangakuchi musento ni okeru toki kaminari yosoku kekka

    Energy Technology Data Exchange (ETDEWEB)

    Katsuragi, Y; Yamauchi, M; Shimizu, M [The Chubu Electric Power Co. Inc., Nagoya (Japan); Sakurano, H [Ishikawa College of Technology, Ishikawa (Japan)

    1993-11-01

    This paper reports the result of observing winter lightnings for three years using a wireless tower on the summit of Mt. Hotatsu in Ishikawa Prefecture (with an altitude of 637 m and a distance of about 8 km to the western seashore) as an observation site. Battery driven lightning surge memory devices were used to measure lightning current waveforms at different parts of the wireless tower and power distribution poles. An automatic stationary camera was used to photograph lightning paths to the wireless tower and a rain radar. The result of the observation may be summarized as follows: about half of the lightnings is of positive polarity and dual polarity; the lightning current having struck the wireless tower flows back into a power distribution pole through the ground; the ratio of lightning on the wireless tower to that on the power distribution pole is 3 to 1; the ratio of lightning on the lightning arrestor on the tower to that on the building is 3 to 7; half of the lightnings on the rain radar has struck directly the radome; and the back-flow ratio of lightning current onto the arrestor in the case of positive polarity is more than double that in the case of negative polarity. 7 refs., 22 figs., 11 tabs.

  17. Comparative Study on the Nutritional Value of Pidan and Salted Duck Egg.

    Science.gov (United States)

    Ganesan, P; Kaewmanee, T; Benjakul, S; Baharin, B S

    2014-01-01

    Pidan and salted duck eggs are of nutritional rich alternative duck egg products which are predominantly consumed in China, Thailand, South Korea and other Chinese migrated countries. Both eggs are rich in proteins, lipids, unsaturated fatty acids and minerals. A Pidan whole egg contains 13.1% of protein, 10.7% of fat, 2.25% of carbohydrate and 2.3% of ash, whereas the salted duck egg contains 14% of protein, 16.6% of fat, 4.1% of carbohydrate and 7.5% of ash. The fresh duck egg contains a range of 9.30-11.80% of protein, 11.40-13.52% of fat, 1.50-1.74% of sugar and 1.10-1.17% of ash. Proteins, lipids, and ash contents are found to be greatly enhanced during the pickling and salting process of pidan and salted duck eggs. However, the alkaline induced aggregation of pidan leads to degradation and subsequent generation of free peptides and amino acids. Very few amino acids are found to be lost during the pickling and storage. However, no such losses of amino acids are reported in salted duck eggs during the salting process of 14 d. Phospholipids and cholesterol contents are lower in pidan oil and salted duck egg yolk oil. Thus, the pidan and salted duck eggs are nutritionally rich alternatives of duck egg products which will benefit the human health during consumption.

  18. Microwave Irradiation of Nanohydroxyapatite from Chicken Eggshells and Duck Eggshells

    Directory of Open Access Journals (Sweden)

    Nor Adzliana Sajahan

    2014-01-01

    Full Text Available Due to similarity in composition to the mineral component of bones and human hard tissues, hydroxyapatite with chemical formula Ca10(PO46(OH2 has been widely used in medical field. Both chicken and duck eggshells are mainly composed of calcium carbonate. An attempt has been made to fabricate nanohydroxyapatite (nHA by chicken (CES and duck eggshells (DES as calcium carbonate source (CaCO3. CES and DES were reacted with diammonium hydrogen [(NH42HPO4] solution and subjected to microwave heating at 15 mins. Under the effect of microwave irradiation, nHA was produced directly in the solution and involved in crystallographic transformation. Sample characterization was done using by X-ray diffraction (XRD, fourier transform infrared spectroscopy (FTIR, and scanning electron microscopy (SEM.

  19. Identification of duck plague virus by polymerase chain reaction

    Science.gov (United States)

    Hansen, W.R.; Brown, Sean E.; Nashold, S.W.; Knudson, D.L.

    1999-01-01

    A polymerase chain reaction (PCR) assay was developed for detecting duck plague virus. A 765-bp EcoRI fragment cloned from the genome of the duck plague vaccine (DP-VAC) virus was sequenced for PCR primer development. The fragment sequence was found by GenBank alignment searches to be similar to the 3a?? ends of an undefined open reading frame and the gene for DNA polymerase protein in other herpesviruses. Three of four primer sets were found to be specific for the DP-VAC virus and 100% (7/7) of field isolates but did not amplify DNA from inclusion body disease of cranes virus. The specificity of one primer set was tested with genome templates from other avian herpesviruses, including those from a golden eagle, bald eagle, great horned owl, snowy owl, peregrine falcon, prairie falcon, pigeon, psittacine, and chicken (infectious laryngotracheitis), but amplicons were not produced. Hence, this PCR test is highly specific for duck plague virus DNA. Two primer sets were able to detect 1 fg of DNA from the duck plague vaccine strain, equivalent to five genome copies. In addition, the ratio of tissue culture infectious doses to genome copies of duck plague vaccine virus from infected duck embryo cells was determined to be 1:100, making the PCR assay 20 times more sensitive than tissue culture for detecting duck plague virus. The speed, sensitivity, and specificity of this PCR provide a greatly improved diagnostic and research tool for studying the epizootiology of duck plague. /// Se desarroll?? una prueba de reacci??n en cadena por la polimerasa para detectar el virus de la peste del pato. Un fragmento EcoRI de 765 pares de bases clonado del genoma del virus vacunal de la peste del pato fue secuenciado para la obtenci??n de los iniciadores de la prueba de la reacci??n en cadena por la polimerasa. En investigaciones de alineaci??n en el banco de genes ('GenBank') se encontr?? que la secuencia del fragmento era similar a los extremos 3a?? de un marco de lectura abierto

  20. Food use and nutrition of black ducks nesting in Maine

    Science.gov (United States)

    Reinecke, K.J.; Owen, R.B.

    1980-01-01

    Based on 32 adult black ducks (Anas rubripes) collected during the nesting seasons of 1974-76, the proportion of macro invertebrates (as aggregate [average] percent of dry weight) in the diet of males, egg-laying females, and postlaying females was 60, 75, and 55%, respectivey. Sample sizes were small, and the differences associated with sex and reproductive condition were not signficant. Molluscs, Isopods, ephemeropteran and odonate nymphs, and coleopteran, trichopteran, and dipteran larvae contributed 74% of the dry weight and 64% of the gross energy ingested. Data from proximate analyses of 9 invertebrate and 9 plant foods were combined with food habits data to estimate the nutrients available to breeding hens. We concluded that females with access to an adequate amount of natural food including invertebrates and the seeds and tubers of aquatic plants would obtain sufficient minerals, protein, and energy for reproduction. Food quality does not appear to limit the density of black ducks nesting in Maine.

  1. Spirit Scans Winter Haven

    Science.gov (United States)

    2006-01-01

    At least three different kinds of rocks await scientific analysis at the place where NASA's Mars Exploration Rover Spirit will likely spend several months of Martian winter. They are visible in this picture, which the panoramic camera on Spirit acquired during the rover's 809th sol, or Martian day, of exploring Mars (April 12, 2006). Paper-thin layers of light-toned, jagged-edged rocks protrude horizontally from beneath small sand drifts; a light gray rock with smooth, rounded edges sits atop the sand drifts; and several dark gray to black, angular rocks with vesicles (small holes) typical of hardened lava lie scattered across the sand. This view is an approximately true-color rendering that combines images taken through the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.

  2. Winter fuels report

    International Nuclear Information System (INIS)

    1995-01-01

    The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and State and local governments on the following topics: distillate fuel oil net production, imports and stocks on a US level and for all Petroleum Administration for Defense Districts (PADD) and product supplied on a US level; propane net production, imports and stocks on a US level and for PADD's I, II, and III; natural gas supply and disposition and underground storage for the US and consumption for all PADD's, as well as selected National average prices; residential and wholesale pricing data for heating oil and propane for those States participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil and petroleum price comparisons for the US and selected cities; and a 6-10 day, 30-Day, and 90-Day outlook for temperature and precipitation and US total heating degree-days by city

  3. Winter fuels report

    Energy Technology Data Exchange (ETDEWEB)

    1990-11-29

    The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and state and local governments on the following topics: distillate fuel oil net production, imports and stocks for all PADD's and product supplied on a US level; propane net product supplied on a US level; propane net production, imports and stocks for Petroleum Administration for Defense Districts (PADD) I, II, and III; natural gas supply and disposition and underground storage for the United States and consumption for all PADD's; residential and wholesale pricing data for propane and heating oil for those states participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil and petroleum price comparisons for the United States and selected cities; and US total heating degree-days by city. 27 figs, 12 tabs.

  4. Seasonal sea surface temperature contrast between the Holocene and last glacial period in the western Arabian Sea (Ocean Drilling Project Site 723A): Modulated by monsoon upwelling

    Digital Repository Service at National Institute of Oceanography (India)

    Naidu, P.D.; Malmgren, B.A.

    Annual, summer, and winter sea surface temperatures (SSTs) in the western Arabian Sea were reconstructed through the last 22 kyr using artificial neural networks (ANNs) based on quantitative analyses of planktic foraminifera. Down-core SST estimates...

  5. Intraseasonal sea surface temperature variability in Indonesian seas

    Science.gov (United States)

    Napitu, A. M.; Gordon, A. L.; Yuan, X.

    2012-12-01

    The satellite-derived sea surface temperature (SST) data, 1998-mid 2012, are used to examine intraseasonal variability (ISV; 20-90 days) across the Indonesian seas. The most energetic ISV is observed in the Banda Sea and across the Indo-Australia basin with an The satellite-derived sea surface temperature (SST) data, 1998-mid 2012, are used to examine intraseasonal variability (ISV; 20-90 days) across the Indonesian seas. The most energetic ISV is observed in the Banda Sea and across the Indo-Australia basin with an average SST standard deviation (STD) between 0.4-0.5°C, with strongest signature during boreal winter. What physical processes force the SST ISV variability within the Indonesian seas? Ocean process, sea-air interaction, or both? To help identify the main forcing, the satellite derived outgoing longwave radiation (OLR) and wind stress data in the region are examined. The OLR shows robust intraseasonal variations and is significantly correlated with the SST, particularly for variability with periods of 30-60 days, with OLR accounting for ~60-70% of the SST variance. The OLR is also maximum during boreal winter. Conversely, the surface wind may play insignificant role in perturbing the SST at intraseasonal timescales as shown by weak correlation between wind stress and SST. We thus suspect that the surface solar flux (suggested by the OLR) is likely more dominant than the surface turbulent heat flux (indicated by the surface wind) as the main source for the ISV in the SST in Indonesian seas. Furthermore the maximum OLR phase, coupled with a period of minimum mixed layer depth, may explain the strong SST variation during boreal winter in Indonesian seas. The influence of the Madden-Julian Oscillation (MJO) on the OLR and SST variability is currently being evaluated.

  6. RELATIONSHIP BETWEEN PROLACTIN HORMONE LEVEL, MOLTING AND DUCK EGG PRODUCTION

    Directory of Open Access Journals (Sweden)

    T. Susanti

    2012-09-01

    Full Text Available The aims of this study were to obtain information on the mechanism of molting and the prolactin hormone levels affecting egg production. The study utilized AP (crossbred of Alabio ♂ with Peking ♀ and PA (crossbred of Peking ♂ and Alabio ♀ ducks with a total of 180 birds. The observed variables were the duration of cessation of egg production before and after molting, the prolactin hormone level in the period of molting, the egg production period before and after molting. The data was analyzed using ANOVA, regression and correlation. The results showed that AP crossbred had fewer molting (23.33% compared to PA (50.00%. The mechanism of molting is always preceded by cessation of egg production, molting and relaying. The prolactin hormone concentrations of AP and PA in the period before and after molting were significantly higher than in the period of molting. At the egg production period before molting, the prolactin hormone concentration of AP ducks was higher than the PA ducks. So that the egg production of AP before molting (0-16 weeks was higher than the PA. The egg production of AP was higher than PA, 256.66±6.00 vs 232.22±6.64 eggs for 48 weeks. So it can be concluded that the prolactin hormone affects the molting and egg production.

  7. Identification of double-yolked duck egg using computer vision.

    Directory of Open Access Journals (Sweden)

    Long Ma

    Full Text Available The double-yolked (DY egg is quite popular in some Asian countries because it is considered as a sign of good luck, however, the double yolk is one of the reasons why these eggs fail to hatch. The usage of automatic methods for identifying DY eggs can increase the efficiency in the poultry industry by decreasing egg loss during incubation or improving sale proceeds. In this study, two methods for DY duck egg identification were developed by using computer vision technology. Transmittance images of DY and single-yolked (SY duck eggs were acquired by a CCD camera to identify them according to their shape features. The Fisher's linear discriminant (FLD model equipped with a set of normalized Fourier descriptors (NFDs extracted from the acquired images and the convolutional neural network (CNN model using primary preprocessed images were built to recognize duck egg yolk types. The classification accuracies of the FLD model for SY and DY eggs were 100% and 93.2% respectively, while the classification accuracies of the CNN model for SY and DY eggs were 98% and 98.8% respectively. The CNN-based algorithm took about 0.12 s to recognize one sample image, which was slightly faster than the FLD-based (about 0.20 s. Finally, this work compared two classification methods and provided the better method for DY egg identification.

  8. Experimental susceptibility of Wood Ducks (Aix sponsa) for West Nile virus

    Science.gov (United States)

    Hofmeister, Erik K.; Porter, Robert E.; Franson, J. Christian

    2015-01-01

    Detection of West Nile virus (WNV) has been reported in a variety of wild ducks in the US, but little is known about the pathogenesis and outcome of exposure of the disease in these species. Previous experimental studies of WNV in ducks either have challenged a small number of ducks with WNV or have tested domesticated ducks. To determine susceptibility and immune response, we challenged 7-wk-old Wood Ducks (Aix sponsa) with a 1999 American Crow (Corvus brachyrhynchos) isolate of WNV. Wood Ducks were susceptible to infection with the virus, and, although clinical signs or mortality were not observed, microscopic lesions were noted, particularly in the heart and brain. West Nile virus viremia peaked on day 2 postinfection (pi) at 104.54 plaque-forming units (PFU) of virus/mL serum and WNV was shed orally (between 102and 102.9 PFU per swab) and cloacally. Specific anti-WNV antibody response was rapid, with anti-WNV IgM detected on day 3 pi followed on day 5 pi by anti-WNV IgG. Neutralizing antibodies were detected by plaque-reduction neutralization assay in one duck on day 4 pi, and in all sampled ducks on day 5. These results indicate that Wood Ducks are susceptible to WNV, but it is unlikely that significant WNV mortality events occur in Wood Ducks or that ducks play a significant role in transmission. However, WNV viremia was sufficient, in theory, to infect mosquitoes, and oral and cloacal shedding of the virus may increase the risk of infection to other waterbirds.

  9. Comparative Pharmacokinetics of Levofloxacin in Healthy and Renal Damaged Muscovy Ducks following Intravenous and Oral Administration

    Directory of Open Access Journals (Sweden)

    Mohamed Aboubakr

    2014-01-01

    Full Text Available The pharmacokinetics aspects of levofloxacin were studied in healthy and experimentally renal damaged Muscovy ducks after single intravenous (IV and oral (PO dose of 10 mg kg−1 bwt. Following IV administration, elimination half-life (t1/2(β and mean residence time (MRT were longer in renal damaged ducks than in healthy ones. Total clearance (Cltot in renal damaged ducks (0.20 L kg−1 h−1 was significantly lower as compared to that in healthy ones (0.41 L kg−1 h−1. Following PO administration, the peak serum concentration (Cmax was higher in renal damaged than in healthy ducks and was achieved at maximum time (tmax of 2.47 and 2.05 h, respectively. The drug was eliminated (t1/2(el at a significant slower rate (3.94 h in renal damaged than in healthy ducks (2.89 h. The pharmacokinetic profile of levofloxacin is altered in renal damaged ducks due to the increased serum levofloxacin concentrations compared with that in clinically healthy ducks. Oral administration of levofloxacin at 10 mg kg−1 bwt may be highly efficacious against susceptible bacteria in ducks. Also, the dose of levofloxacin should be reduced in renal damaged ducks. Pharmacokinetic/pharmacodynamic integration revealed significantly higher values for Cmax/MIC and AUC/MIC ratios in renal damaged ducks than in healthy ones, indicating the excellent pharmacokinetic characteristics of levofloxacin in renal damaged ducks.

  10. Spreading Of Avian Flu On Duck And Its Impact On Social Economy: Lesson Learnt From Avian Flu Cases On Chicken

    Directory of Open Access Journals (Sweden)

    Nyak Ilham

    2013-06-01

    Full Text Available Bird flu disease that attacks duck dismissed the notion of duck immune to bird flu disease. Learning from the experience of bird flu disease that attacks poultry in the year of 2004-2005, necessary to measure the spread of disease prevention bird flu in ducks. This paper aims to describe the business and trade patterns of duck associated with the spread of avian influenza and predict the socio-economic impact of bird flu on duck farms in Indonesia. Duck rearing patterns mostly are in the extensive and semi-intensive system, that have large potential disease transmission occured between duck and wild. Illegal trade in the crossborder region and imports from countries that re-export it, ias alo become potential as well as the entry point to the bird flu virus in Indonesia. Ducks trade between regions by land transportation is difficult to control as well becomes the potential media to spread of the virus to a wider area. The economic impact of bird flu on duck business occured due to the death of ducks, decline in production and loss of job opportunities, while that on demand reduction was not significant. Small scale farmers that were bankrupt as a result of bird flu outbreaks may require technical assistance and access to capital for recovery. In the future, development of ducks business should be directed at duck farms into a semi-intensive and intensive system to facilitate the control of epidemic diseases

  11. Winter fuels report

    Energy Technology Data Exchange (ETDEWEB)

    1995-01-13

    The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and State and local governments on the following topics: distillate fuel oil net production, imports and stocks on a US level and for all Petroleum Administration for Defense Districts (PADD) and product supplied on a US level; propane net production, imports and stocks on a US level and for PADD`s I, II, and III; natural gas supply and disposition and underground storage for the US and consumption for all PADD`s, as well as selected National average prices; residential and wholesale pricing data for heating oil and propane for those States participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil and petroleum price comparisons for the US and selected cities; and a 6-10 day, 30-Day, and 90-Day outlook for temperature and precipitation and US total heating degree-days by city.

  12. Klaus Winter (1930 - 2015)

    CERN Multimedia

    2015-01-01

    We learned with great sadness that Klaus Winter passed away on 9 February 2015, after a long illness.   Klaus was born in 1930 in Hamburg, where he obtained his diploma in physics in 1955. From 1955 to 1958 he held a scholarship at the Collège de France, where he received his doctorate in nuclear physics under the guidance of Francis Perrin. Klaus joined CERN in 1958, where he first participated in experiments on π+ and K0 decay properties at the PS, and later became the spokesperson of the CHOV Collaboration at the ISR. Starting in 1976, his work focused on experiments with the SPS neutrino beam. In 1984 he joined Ugo Amaldi to head the CHARM experiment, designed for detailed studies of the neutral current interactions of high-energy neutrinos, which had been discovered in 1973 using the Gargamelle bubble chamber at the PS. The unique feature of the detector was its target calorimeter, which used large Carrara marble plates as an absorber material. From 1984 to 1991, Klau...

  13. Winter fuels report

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-04

    The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and state and local governments on the following topics: distillate fuel oil net production, imports and stocks for all PADD's and product supplied on a US level; propane net production, imports and stocks for Petroleum Administration for Defense Districts (PADD) I, II, and III; natural gas supply and disposition, underground storage, and consumption for all PADD's; residential and wholesale pricing data for propane and heating oil for those states participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil price comparisons for the United States and selected cities; and US total heating degree-days by city. This report will be published weekly by the EIA starting the first week in October 1990 and will continue until the first week in April 1991. The data will also be available electronically after 5:00 p.m. on Thursday during the heating season through the EIA Electronic Publication System (EPUB). 12 tabs.

  14. Interdecadal variability of winter precipitation in Southeast China

    OpenAIRE

    Zhang, L.; Zhu, X.; Fraedrich, K.; Sielmann, F.; Zhi, X.

    2014-01-01

    Interdecadal variability of observed winter precipitation in Southeast China (1961–2010) is characterized by the first empirical orthogonal function of the three-monthly Standardized Precipitation Index (SPI) subjected to a 9-year running mean. For interdecadal time scales the dominating spatial modes represent monopole features involving the Arctic Oscillation (AO) and the sea surface temperature (SST) anomalies. Dynamic composite analysis (based on NCEP/NCAR reanalyzes) reveals the followin...

  15. Effects of alfalfa meal on carcase quality and fat metabolism of Muscovy ducks.

    Science.gov (United States)

    Jiang, J F; Song, X M; Huang, X; Wu, J L; Zhou, W D; Zheng, H C; Jiang, Y Q

    2012-01-01

    1. The effects of alfalfa meal on carcase quality and fat metabolism of Muscovy duck were evaluated. The objective of this research was to establish whether alfalfa meal can reduce fat content and improve carcase quality of Muscovy duck. Animal products with a high fat content present a risk factor for many diseases. Reducing fat content in poultry products is an important goal for the poultry industry. 2. A total of 240 14-d-old white Muscovy ducks were selected and randomly allocated to 1 of 4 dietary treatments containing 0, 3, 6, and 9% of alfalfa meal for 5 weeks. Growth performances were recorded and carcase characteristics and lipid parameters were analysed. 3. Results showed that 3, 6, and 9% alfalfa meal in diet had no significant effects on growth performance of Muscovy ducks from 14 to 49 d of age. Ducks given 3, 6, and 9% alfalfa meal had significantly higher dressing percentage and lower abdominal fat percentage compared with those given no alfalfa meal. Ducks given 9% alfalfa meal had higher breast meat percentage compared with those given no alfalfa meal. The concentrations of triglyceride, total cholesterol, low density lipoprotein (LDL), very low density lipoprotein (VLDL) and free fatty acid in serum of ducks fed on alfalfa meal decreased. Alfalfa meal in the diet decreased abdominal fat percentage and improved carcase traits of Muscovy duck. 4. The study showed that dietary alfalfa meal decreased abdominal fat percentage and improved carcase traits, without an adverse effect on performance.

  16. Tissue distribution of metals in white-fronted geese and spot-billed ducks from Korea.

    Science.gov (United States)

    Kim, Jungsoo; Oh, Jong-Min

    2013-07-01

    This study presents concentrations of Fe, Zn, Mn, Cu, Pb and Cd in livers, kidneys, muscles and bones of white-fronted geese Anser albifrons (geese) and spot-billed ducks Anas poecilorhyncha (ducks). Iron in livers, kidneys and muscles, Zn in muscles, Mn and Cd in every tissue, Cu in livers, muscles and bones and Pb in bones differed between species, and there were significant differences among tissues in both species. Essential elements such as Fe, Zn, Mn and Cu concentrations were within the background levels. Lead concentrations in livers of 7 of 14 geese and 7 of 19 ducks and in bones of 4 of 19 ducks exceeded background concentrations for waterfowl (5 μg/g dw for the liver, 10 μg/g dw for the bone). Almost all samples of both species had the background Cd concentrations in the liver (33 of 33 geese and ducks) and kidney (14 geese and 18 ducks). Tissue concentrations of Cd were greater in geese than ducks. In contrast, tissue concentrations of Pb in bones were greater in ducks than in geese. These different trends for Cd and Pb reflect a short and/or long term difference in exposure and degree of accumulation of these metals.

  17. Effects of alfalfa meal on the intestinal microbial diversity and immunity of growing ducks.

    Science.gov (United States)

    Jiang, J F; Song, X M; Wu, J L; Jiang, Y Q

    2014-12-01

    This study was conducted to investigate the effects of alfalfa meal diets on the intestinal microbial diversity and immunity of growing egg-type ducks. A total of 128 healthy 7-week-old female egg-type Shaoxing ducks were selected and randomly assigned into four dietary treatments: 0%, 3%, 6% and 9% alfalfa meal for 8 weeks. Each treatment consisted of four replicates of eight ducks each. Polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) was used to characterize the microbiota. The results showed that the DGGE fingerprints of the V6-V8 fragments of the 16S rRNA from the caeca and faeces of ducks fed 3%, 6% and 9% alfalfa meal had significantly higher microbiota species richness than those fed 0% alfalfa meal (p ducks fed 3%, 6% and 9% alfalfa meal was significantly higher than those fed 0% alfalfa meal (p 0.05), and the 3-9% alfalfa meal did not affect the growth performance of the growing egg-type ducks. The proliferation of T and B lymphocytes was significantly greater (p ducks. Dietary alfalfa meal supplementation increases intestinal microbial community diversity and improves of the immune response growing egg-type ducks. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  18. Lead exposure affects health indices in free-ranging ducks in Argentina.

    Science.gov (United States)

    Ferreyra, Hebe; Beldomenico, Pablo M; Marchese, Krysten; Romano, Marcelo; Caselli, Andrea; Correa, Ana I; Uhart, Marcela

    2015-05-01

    Numerous experiments under controlled conditions and extensive investigation of waterfowl die-offs have demonstrated that exposure to lead from spent gunshot is highly detrimental to the health of waterfowl. However, few studies have focused on examining the more subtle sub-lethal effects of lead toxicity on ducks in non-experimental settings. In our study, the health of ducks exposed to varying amounts of lead under natural conditions was assessed by correlating individual lead exposure with relevant indices of health. Based on hunter-killed wild ducks in Argentina, we measured spleen mass, body condition, examined bone marrow smears, and determined Ca and P in bone tissue. In free-ranging live-trapped ducks we determined basic hematology and aminolevulinic acid dehydratase activity. Using multivariate analyses, we found that, when controlling for the potential confounding effect of site type, year, duck species, body mass and age, lead levels in the liver were negatively associated with body condition and spleen mass. Spleen mass was also lower in ducks with higher lead levels in their bones. In live ducks, high blood lead levels were associated with low packed cell volume and red cell morphologic abnormalities. These findings suggest that, despite the lack of recorded lead-induced mortality in the region, lead exposure results in less conspicuous but still significant impacts on the health of ducks, which could have serious implications for their conservation. Moreover, this evidence further supports the need for urgently banning lead shot in the region.

  19. Sentinel model for influenza A virus monitoring in free-grazing ducks in Thailand.

    Science.gov (United States)

    Boonyapisitsopa, Supanat; Chaiyawong, Supassama; Nonthabenjawan, Nutthawan; Jairak, Waleemas; Prakairungnamthip, Duangduean; Bunpapong, Napawan; Amonsin, Alongkorn

    2016-01-01

    Influenza A virus (IAV) can cause influenza in birds and mammals. In Thailand, free-grazing ducks are known IAV reservoirs and can spread viruses through frequent movements in habitats they share with wild birds. In this study, the sentinel model for IAV monitoring was conducted over 4 months in two free-grazing duck flocks. IAV subtypes H4N6 (n=1) and H3N8 (n=5) were isolated from sentinel ducks at the ages of 13 and 15 weeks. Clinical signs of depression and ocular discharge were observed in the infected ducks. Phylogenetic analysis and genetic characterization of the isolated IAVs indicated that all Thai IAVs were clustered in the Eurasian lineage and pose low pathogenic avian influenza characteristics. Serological analysis found that antibodies against IAVs could be detected in the ducks since 9-weeks-old. In summary, our results indicate that the sentinel model can be used for IAV monitoring in free-grazing duck flocks. Since free-grazing ducks are potential reservoirs and transmitters of IAVs, routine IAV surveillance in free-grazing duck flocks can be beneficial for influenza prevention and control strategies. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Protective efficacy of an inactivated vaccine against H9N2 avian influenza virus in ducks.

    Science.gov (United States)

    Teng, Qiaoyang; Shen, Weixia; Liu, Qinfang; Rong, Guangyu; Chen, Lin; Li, Xuesong; Chen, Hongjun; Yang, Jianmei; Li, Zejun

    2015-09-17

    Wild ducks play an important role in the evolution of avian influenza viruses (AIVs). Domestic ducks in China are known to carry and spread H9N2 AIVs that are thought to have contributed internal genes for the recent outbreak of zoonotic H7N9 virus. In order to protect animal and public health, an effective vaccine is urgently needed to block and prevent the spread of H9N2 virus in ducks. We developed an inactivated H9N2 vaccine (with adjuvant Montanide ISA 70VG) based on an endemic H9N2 AIV and evaluated this vaccine in ducks. The results showed that the inactivated H9N2 vaccine was able to induce a strong and fast humoral immune response in vaccinated ducks. The hemagglutination inhibition titer in the sera increased fast, and reached its peak of 12.3 log2 at 5 weeks post-vaccination in immunized birds and remained at a high level for at least 37 weeks post-vaccination. Moreover, viral shedding was completely blocked in vaccinated ducks after challenge with a homologous H9N2 AIV at both 3 and 37 weeks post-vaccination. The results of this study indicate that the inactivated H9N2 vaccine induces high and prolonged immune response in vaccinated ducks and are efficacious in protecting ducks from H9N2 infection.

  1. Epidemiologic Investigation of Riemerella anatipestifer in a Commercial Duck Company by Serotyping and DNA Fingerprinting

    Science.gov (United States)

    A commercial duck company that raises approximately two million Pekin ducks per year experienced an outbreak of Riemerella anatipestifer(RA)on nine farms over a one year period. Due to concerns that the bacteria was being spread from farm to farm, an investigation using serotyping and DNA fingerprin...

  2. [Nitrogen cycling in rice-duck mutual ecosystem during double cropping rice growth season].

    Science.gov (United States)

    Zhang, Fan; Chen, Yuan-Quan; Sui, Peng; Gao, Wang-Sheng

    2012-01-01

    Raising duck in paddy rice field is an evolution of Chinese traditional agriculture. In May-October 2010, a field experiment was conducted in a double cropping rice region of Hunan Province, South-central China to study the nitrogen (N) cycling in rice-duck mutual ecosystem during early rice and late rice growth periods, taking a conventional paddy rice field as the control. Input-output analysis method was adopted. The N output in the early rice-duck mutual ecosystem was 239.5 kg x hm(-2), in which, 12.77 kg x hm(-2) were from ducks, and the N output in the late rice-duck mutual ecosystem was 338.7 kg x hm(-2), in which, 23.35 kg x hm(-2) were from ducks. At the present N input level, there existed soil N deficit during the growth seasons of both early rice and late rice. The N input from duck sub-system was mainly from the feed N, and the cycling rate of the duck feces N recycled within the system was 2.5% during early rice growth season and 3.5% during late rice growth season. After late rice harvested, the soil N sequestration was 178.6 kg x hm(-2).

  3. Transmission dynamics of the recently-identified BYD virus causing duck egg-drop syndrome.

    Directory of Open Access Journals (Sweden)

    Naveen K Vaidya

    Full Text Available Baiyangdian (BYD virus is a recently-identified mosquito-borne flavivirus that causes severe disease in ducks, with extremely rapid transmission, up to 15% mortality within 10 days and 90% reduction in egg production on duck farms within 5 days of infection. Because of the zoonotic nature of flaviviruses, the characterization of BYD virus and its epidemiology are important public health concerns. Here, we develop a mathematical model for the transmission dynamics of this novel virus. We validate the model against BYD outbreak data collected from duck farms in Southeast China, as well as experimental data obtained from an animal facility. Based on our model, the basic reproductive number of BYD virus is high (R(0 = 21 indicating that this virus is highly transmissible, consistent with the dramatic epidemiology observed in BYDV-affected duck farms. Our results indicate that younger ducks are more vulnerable to BYD disease and that ducks infected with BYD virus reduce egg production (to about 33% on average for about 3 days post-infection; after 3 days infected ducks are no longer able to produce eggs. Using our model, we predict that control measures which reduce contact between mosquitoes and ducks such as mosquito nets are more effective than insecticides.

  4. Comparative effects of fumonisins on sphingolipid metabolism and toxicity in ducks and turkeys.

    Science.gov (United States)

    Benlasher, Emad; Geng, Xiuyu; Nguyen, Ngoc Thanh Xuan; Tardieu, Didier; Bailly, Jean-Denis; Auvergne, Alain; Guerre, Philippe

    2012-03-01

    Fumonisins (FBs) are mycotoxins that are found worldwide in maize and maize products. Their main toxic effects have been well characterized in poultry, but differences between species have been demonstrated. Ducks appeared very sensitive to toxicity, whereas turkeys are more resistant. At the same time, alterations of sphingolipid metabolism, with an increase of the concentration of the free sphinganine (Sa) in serum and liver, have been demonstrated in the two species, but the link between the toxicity of FBs and Sa accumulation remains difficult to interpret. The aim of the present work was to compare the effects of FBs (10 mg FB1 + FB2/kg body weight) on sphingolipid metabolism in ducks and turkeys. Growth, feed consumption, and serum biochemistry were also investigated to evaluate toxicity. The main results showed that FBs increased Sa concentrations in liver and serum in ducks and turkeys, but these accumulations were not directly correlated with toxicity. Sa accumulation was higher in the livers of turkeys than in ducks, whereas Sa levels were higher in the sera of ducks than in turkeys. Hepatic toxicity was more pronounced in ducks than in turkeys and accompanied a decrease of body weight and an increase of serum biochemistry in ducks but not in turkeys. So, although FBs increase Sa concentration in the livers of both species, this effect is not directly proportional to toxicity. The mechanisms of FB toxicity and/or the mechanisms of protection of ducks and turkeys to the Sa accumulation within the liver remain to be established.

  5. Inositol-P6 induced structural changes in duck major haemoglobin

    African Journals Online (AJOL)

    Bamiji Babalola

    2011-11-02

    Nov 2, 2011 ... of duck (Anas platyrhinchos) have been carried out in the presence of ... dependence profile of the apparent second-order rate constant of both oxy- and ... Key words: 5,5‟-Dithiobis (2-nitrobenzoate), duck, haemoglobin, inositol-P6, sulphydryl group. ... Saigo, 1999), thereby making it possible to detect the.

  6. 78 FR 14413 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel LUCKY DUCK; Invitation for...

    Science.gov (United States)

    2013-03-05

    ... Administrative Waiver of the Coastwise Trade Laws: Vessel LUCKY DUCK; Invitation for Public Comments AGENCY... should refer to docket number MARAD-2013-0019. Written comments may be submitted by hand or by mail to... LUCKY DUCK is: Intended Commercial Use Of Vessel: ``The vessel is to be operated as a sailing...

  7. A polymerase chain reaction assay for detection of virulent and attenuated strains of duck plague virus.

    Science.gov (United States)

    Xie, Liji; Xie, Zhixun; Huang, Li; Wang, Sheng; Huang, Jiaoling; Zhang, Yanfang; Zeng, Tingting; Luo, Sisi

    2017-11-01

    Sequence analysis of duck plague virus (DPV) revealed that there was a 528bp (B fragment) deletion within the UL2 gene of DPV attenuated vaccine strain in comparison with field virulent strains. The finding of gene deletion provides a potential differentiation test between DPV virulent strain and attenuated strain based on their UL2 gene sizes. Thus we developed a polymerase chain reaction (PCR) assay targeting to the DPV UL2 gene for simultaneous detection of DPV virulent strain and attenuated strain, 827bp for virulent strain and 299bp for attenuated strain. This newly developed PCR for DPV was highly sensitive and specific. It detected as low as 100fg of DNA on both DPV virulent and attenuated strains, no same size bands were amplified from other duck viruses including duck paramyxovirus, duck tembusu virus, duck circovirus, Muscovy duck parvovirus, duck hepatitis virus type I, avian influenza virus and gosling plague virus. Therefore, this PCR assay can be used for the rapid, sensitive and specific detection of DPV virulent and attenuated strains affecting ducks. Copyright © 2017. Published by Elsevier B.V.

  8. Phenology of abundance of bivalve spat and of their epibenthic predators: limited evidence for mismatches after cold winters

    NARCIS (Netherlands)

    Dekker, R.; Beukema, J.J.

    2014-01-01

    Annual recruitment of bivalves in the Wadden Sea is usually more successful in summers after cold than after mild winters. The new generation (0-group) of the main predators (shrimps and shore crabs) of early benthic stages of bivalves appear later in spring on tidal flats after colder winters. If

  9. Five Year Mean Sea-surface Salinity in the Northern Gulf of Mexico for 2005 through 2009

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These images were created by combining the mean sea-surface salinity values to produce seasonal representations for winter, spring, summer and fall. Winter includes...

  10. Five Year Mean Sea-Surface Temperature in the Northern Gulf of Mexico for 2005 through 2009

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These images were created by combining the mean sea-surface temperature values to produce seasonal representations for winter, spring, summer and fall. Winter...

  11. Seasonal forecasts of northern hemisphere winter 2009/10

    International Nuclear Information System (INIS)

    Fereday, D R; Maidens, A; Arribas, A; Scaife, A A; Knight, J R

    2012-01-01

    Northern hemisphere winter 2009/10 was exceptional for atmospheric circulation: the North Atlantic Oscillation (NAO) index was the lowest on record for over a century. This contributed to cold conditions over large areas of Eurasia and North America. Here we use two versions of the Met Office GloSea4 seasonal forecast system to investigate the predictability of this exceptional winter. The first is the then operational version of GloSea4, which uses a low top model and successfully predicted a negative NAO in forecasts produced in September, October and November 2009. The second uses a new high top model, which better simulates sudden stratospheric warmings (SSWs). This is particularly relevant for 2009/10 due to its unusual combination of a strong El Niño and an easterly quasi-biennial oscillation (QBO) phase, favouring SSW development. SSWs are shown to play an influential role in surface conditions, producing a stronger sea level pressure signal and improving predictions of the 2009/10 winter. (letter)

  12. Hydrophobic duck feathers and their simulation on textile substrates for water repellent treatment

    International Nuclear Information System (INIS)

    Liu Yuyang; Chen Xianqiong; Xin, J H

    2008-01-01

    Inspired by the non-wetting phenomena of duck feathers, the water repellent property of duck feathers was studied at the nanoscale. The microstructures of the duck feather were investigated by a scanning electron microscope (SEM) imaging method through a step-by-step magnifying procedure. The SEM results show that duck feathers have a multi-scale structure and that this multi-scale structure as well as the preening oil are responsible for their super hydrophobic behavior. The microstructures of the duck feather were simulated on textile substrates using the biopolymer chitosan as building blocks through a novel surface solution precipitation (SSP) method, and then the textile substrates were further modified with a silicone compound to achieve low surface energy. The resultant textiles exhibit super water repellent properties, thus providing a simple bionic way to create super hydrophobic surfaces on soft substrates using flexible material as building blocks

  13. Effect of Housing System, Slaughter Age and Sex on Slaughter and Carcass Parameters of Broiler Ducks

    Directory of Open Access Journals (Sweden)

    Cyril Hrnčár

    2014-11-01

    Full Text Available The aim of this study was to determine the effects of housing system slaughterage and sex on performance and carcass parameters of broiler ducks. Theexperiment was carried out in half-operation conditions experimental base ofDepartment of Poultry Science and Small Animal Husbandry of Slovak Universityof Agriculture in Nitra. A total of 60 one day old ducklings (type Peking DuckWhite were randomly divided to 2 housing groups: three-floor cage system anddeep litter system, both under uniform microclimate conditions. The housingsystem, slaughter age and sex significantly affected the slaughter weights ofbroiler ducks in 49 and 56 day of fattening. The results of this study showed the influenceof housing system, sex and slaughter age on slaughter and carcass parameters.The slaughter and carcass parameters were statistically higher (P0.05. The some slaughterand carcass parameters of male ducks were statistically higher (P<0.05 comparedwith female ducks.

  14. Effects of Alfalfa Meal on Growth Performance and Gastrointestinal Tract Development of Growing Ducks

    Directory of Open Access Journals (Sweden)

    J. F. Jiang

    2012-10-01

    Full Text Available A study was conducted to evaluate effects of alfalfa meal on growth performance and gastrointestinal tract development of growing layer ducks to provide evidence for application of alfalfa meal in the duck industry. Two hundred and fifty-six healthy Shaoxing 7-wk old growing layer ducks were selected and randomly allocated to 1 of 4 dietary treatments based on corn and soybean meal and containing 0, 3, 6, and 9% of alfalfa meal for 8 wks. Each treatment consisted of 4 replicates of 16 ducks each. Briefly, birds were raised in separate compartments, and each compartment consisted of three parts: indoor floor house, adjacent open area and a connecting water area. The results showed: i Growing ducks fed alfalfa meal diet were not significantly different in average daily gain, feed intake and gain-to-feed ratio from those fed no alfalfa diet (p>0.05. ii Alfalfa meal increased the ratio crop, gizzard to live weight, caecum to live weight, the caecum index of growing ducks (p<0.05. iii Villus height in duodenum and jejunum of growing ducks increased significantly with the increase of alfalfa meal levels (p<0.05. Crypt depth in duodenum and jejunum of growing ducks decreased significantly with the increase of alfalfa meal levels (p<0.05. This experiment showed that feeding of alfalfa meal to growing layer ducks could improve gastrointestinal tract growth and small intestinal morphology without effect on performance. This experiment provides evidence that alfalfa meal is a very valuable feedstuff for growing layer ducks.

  15. Local Duck Fanning At Paddy Three Times Planting Areas ("IP Padi 300"

    Directory of Open Access Journals (Sweden)

    Setioko A.R

    2000-03-01

    Full Text Available Most of duck husbandry in Indonesia is still run traditionally, herded in rice field or in the swampy area. This kind of husbandry seemed to be much preferred by farmers as they thought it was a simple and did not need high skill and high capital "IP padi 300" was a term of rice planting system tree times instead of twice in a year. This kind of changing might have significantly affected duck faming. The objective of the study was to observe the interactively effect of "IP padi 300" to duck husbandry at the same area. Two locations were choosen (Subang, West Jawa and Pemalang, Central Java with 5 farmers at each location to be involved in the study. As many as 1200 laying pullet ducks were distributed to 10 farmers at two locations. The farmers were suggested to raise laying ducks with their own systems (fully intensive, semi intensive and fully herded and were observed for 6 months. Biota was observed on both field and in the crop of the laying ducks. There was an interactive effect of "IP padi 300" and the duck farming on the same area. The availability of feed was increased on the "IP padi 300", which gave benefit to duck farming especially fue herded system, not to go far from owner's home base. Whilst the benefit to "IP padi 300" was assumed to the reduction of pest and desease, which was frequently attacked the rice field. The production of egg from herded duck was very fluctuative due to the movement and feed availability in the rice field. Field biota in Subang and Pemalang was very much the same in profile, although "golden snail" was only found in Subang. Ducks' crop content seemed to be very much similar with the profile of field biota, although rice grain was the most in the crop. Thus, it was found that field biota was not reduced by "IP padi 300", in fact it was rather increased.

  16. Winter/Summer Monsoon Experiment

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Winter/Summer Monsoon Experiment (MONEX) was conducted during the First Global GARP (Global Atmospheric Research Program) Experiment (FGGE). An international...

  17. Temporal flexibility of reproduction in temperate-breeding dabbling ducks

    Science.gov (United States)

    Krapu, Gary L.

    2000-01-01

    I compared nesting intervals during three consecutive years in five species of temperate-nesting dabbling ducks (Mallard [Anas platyrhynchos], Northern Pintail [Anas acuta], Northern Shoveler [Anas clypeata], Blue-winged Teal [Anas discors], Gadwall [Anas strepera]) and assessed whether differences existed in timing of refractoriness. Most nesting by females of all five species ended by the summer solstice. Nesting ended earliest for Northern Shovelers and Northern Pintails and latest for Gadwalls. Some Mallards, Blue-winged Teal, and Gadwalls continued to nest into mid- and late summer, whereas Northern Shovelers and Northern pintails did not. Mallards, Blue-winged Teal, and Gadwalls accounted for 99% (81 of 82) of flightless broods resulting from nests initiated during mid- or late summer in North Dakota and 98% (58 of 59) of flightless juveniles shot on or after 1 October by a random sample of duck hunters from across the United States. Early cessation of breeding by Northern Shovelers may have evolved in response to the species' limited flexibility in diet. Photorefractory mechanisms that limit most breeding to spring presumably evolved in response to severe constraints on reproductive success when nesting continued through summer(e.g. mortality of late-hatched young and molting females due to low temperatures). Interspecific differences in photosensitivity may account for variation in timing of cessation of nesting in late spring, but controlled experiments are needed to assess the possible role of non-photic influences. My results suggest that the refractory mechanisms controlling length of the breeding in temperate-nesting dabbling ducks are more varied and complex than previously thought, with non-photic influences (e.g. water conditions, food availability, food quality) having a larger role than indicated by earlier research.

  18. Salted and preserved duck eggs: a consumer market segmentation analysis.

    Science.gov (United States)

    Arthur, Jennifer; Wiseman, Kelleen; Cheng, K M

    2015-08-01

    The combination of increasing ethnic diversity in North America and growing consumer support for local food products may present opportunities for local producers and processors in the ethnic foods product category. Our study examined the ethnic Chinese (pop. 402,000) market for salted and preserved duck eggs in Vancouver, British Columbia (BC), Canada. The objective of the study was to develop a segmentation model using survey data to categorize consumer groups based on their attitudes and the importance they placed on product attributes. We further used post-segmentation acculturation score, demographics and buyer behaviors to define these groups. Data were gathered via a survey of randomly selected Vancouver households with Chinese surnames (n = 410), targeting the adult responsible for grocery shopping. Results from principal component analysis and a 2-step cluster analysis suggest the existence of 4 market segments, described as Enthusiasts, Potentialists, Pragmatists, Health Skeptics (salted duck eggs), and Neutralists (preserved duck eggs). Kruskal Wallis tests and post hoc Mann-Whitney tests found significant differences between segments in terms of attitudes and the importance placed on product characteristics. Health Skeptics, preserved egg Potentialists, and Pragmatists of both egg products were significantly biased against Chinese imports compared to others. Except for Enthusiasts, segments disagreed that eggs are 'Healthy Products'. Preserved egg Enthusiasts had a significantly lower acculturation score (AS) compared to all others, while salted egg Enthusiasts had a lower AS compared to Health Skeptics. All segments rated "produced in BC, not mainland China" products in the "neutral to very likely" range for increasing their satisfaction with the eggs. Results also indicate that buyers of each egg type are willing to pay an average premium of at least 10% more for BC produced products versus imports, with all other characteristics equal. Overall

  19. The meaning of nuclear winter

    International Nuclear Information System (INIS)

    Geiger, H.J.

    1987-01-01

    In this paper the author reviews the history and origins of the basic ideas underlying nuclear winter; and findings and predictions of several groups regarding this topic. The author reviews some of the further developments and scientific analyses regarding nuclear winter since the initial announcements of 1983, touching on some of the revisions and controversies and trying to indicate the current status of the field

  20. The Growth of Protein Crystals Using McDUCK

    Science.gov (United States)

    Ewing, Felicia; Wilson, Lori; Nadarajah, Arunan; Pusey, Marc

    1998-01-01

    Most of the current microgravity crystal growth hardware is optimized to produce crystals within the limited time available on orbit. This often results in the actual nucleation and growth process being rushed or the system not coming to equilibrium within the limited time available. Longer duration hardware exists, but one cannot readily pick out crystals grown early versus those which nucleated and grew more slowly. We have devised a long duration apparatus, the Multi-chamber Dialysis Unit for Crystallization Kinetics, or McDUCK. This apparatus-is a series of protein chambers, stacked upon a precipitant reservoir chamber. All chambers are separated by a dialysis membrane, which serves to pass small molecules while retaining the protein. The volume of the Precipitant chamber is equal to the sum of the volumes of the protein chamber. In operation, the appropriate chambers are filled with precipitant solution or protein solution, and the McDUCK is placed standing upright, with the precipitant chamber on the bottom. The precipitant diffuses upwards over time, with the time to reach equilibration a function of the diffusivity of the precipitant and the overall length of the diffusion pathway. Typical equilibration times are approximately 2-4 months, and one can readily separate rapid from slow nucleation and growth crystals. An advantage on Earth is that the vertical precipitant concentration gradient dominates that of the solute, thus dampening out solute density gradient driven convective flows. However, large Earth-grown crystals have so far tended to be more two dimensional. Preliminary X-ray diffraction analysis of lysozyme crystals grown in McDUCK have indicated that the best, and largest, come from the middle chambers, suggesting that there is an optimal growth rate. Further, the improvements in diffraction resolution have been better signal to noise ratios in the low resolution data, not an increase in resolution overall. Due to the persistently large crystals

  1. Irradiation studies of mallard duck eggs material containing Mirex

    International Nuclear Information System (INIS)

    Lane, R.H.; Grodner, R.M.; Graves, J.L.

    1976-01-01

    Eggs containing Mirex (dodecachloropentacyclo[5.3.0.0 2 , 6 .0 3 , 9 .0 4 , 8 ]decane) from mallard ducks (Anas platyrhychos l.), fed diets with the insecticide incorporated at levels of 1 and 100 ppM for 25 weeks, were subjected to ultraviolet (uv) and γ irradiation. Seven derivatives were obtained on photolysis and eight derivatives were obtained from γ irradiation. Irradiation products appeared to be mono and dihydro derivatives of Mirex. Structural assignments for two monohydro derivatives and three dihydro derivatives were made on the basis of retention time and mass spectral data

  2. Two-Dimensional Zymography of Proteases from Steatotic Duck Liver.

    Science.gov (United States)

    Wilkesman, Jeff; Padrón, María Fernanda; Kurz, Liliana; Rémignon, Hervé

    2017-01-01

    Protease activity present in liver cells with steatosis can be electrophoretically characterized. Zymographic techniques allow semi-quantitative results, successfully detecting cathepsin and metalloprotease activity using polyacrylamide gels copolymerized with gelatin and quantified by densitometry. By using specific inhibitors, the identity of the proteases can be confirmed. 2D zymography allows the determination of both M r. and pI of the metalloprotease and cathepsin activity present in the homogenates. The analysis of liver proteases activities in force fed ducks may elucidate the mechanisms behind steatosis development.

  3. Archiving California’s historical duck nesting data

    Science.gov (United States)

    Ackerman, Joshua T.; Herzog, Mark P.; Brady, Caroline; Eadie, John M.; Yarris, Greg S.

    2015-07-14

    The U.S. Geological Survey (USGS), in partnership with the California Waterfowl Association (CWA) and other organizations, have compiled large datasets on the nesting ecology and management of dabbling ducks and associated upland nesting birds (Northern Harriers [Circus cyaneus], Short-eared Owls [Asio flammeus], Ring-necked Pheasants [Phasianus colchicus], and American Bitterns [Botaurus lentiginosus]) throughout California on Federal Refuges, State Wildlife Areas, and private lands, some participating in State and Federal habitat programs. These datasets encompass several long-term monitoring programs at multiple sites throughout California, and include data from more than 26,000 nests and span nearly 30 years.

  4. Age-class separation of blue-winged ducks

    Science.gov (United States)

    Hohman, W.L.; Moore, J.L.; Twedt, D.J.; Mensik, John G.; Logerwell, E.

    1995-01-01

    Accurate determination of age is of fundamental importance to population and life history studies of waterfowl and their management. Therefore, we developed quantitative methods that separate adult and immature blue-winged teal (Anas discors), cinnamon teal (A. cyanoptera), and northern shovelers (A. clypeata) during spring and summer. To assess suitability of discriminant models using 9 remigial measurements, we compared model performance (% agreement between predicted age and age assigned to birds on the basis of definitive cloacal or rectral feather characteristics) in different flyways (Mississippi and Pacific) and between years (1990-91 and 1991-92). We also applied age-classification models to wings obtained from U.S. Fish and Wildlife Service harvest surveys in the Mississippi and Central-Pacific flyways (wing-bees) for which age had been determined using qualitative characteristics (i.e., remigial markings, shape, or wear). Except for male northern shovelers, models correctly aged lt 90% (range 70-86%) of blue-winged ducks. Model performance varied among species and differed between sexes and years. Proportions of individuals that were correctly aged were greater for males (range 63-86%) than females (range 39-69%). Models for northern shovelers performed better in flyway comparisons within year (1991-92, La. model applied to Calif. birds, and Calif. model applied to La. birds: 90 and 94% for M, and 89 and 76% for F, respectively) than in annual comparisons within the Mississippi Flyway (1991-92 model applied to 1990-91 data: 79% for M, 50% for F). Exclusion of measurements that varied by flyway or year did not improve model performance. Quantitative methods appear to be of limited value for age separation of female blue-winged ducks. Close agreement between predicted age and age assigned to wings from the wing-bees suggests that qualitative and quantitative methods may be equally accurate for age separation of male blue-winged ducks. We interpret annual

  5. Time-lapse imagery of Adélie penguins reveals differential winter strategies and breeding site occupation.

    Science.gov (United States)

    Black, Caitlin; Southwell, Colin; Emmerson, Louise; Lunn, Daniel; Hart, Tom

    2018-01-01

    Polar seabirds adopt different over-wintering strategies to survive and build condition during the critical winter period. Penguin species either reside at the colony during the winter months or migrate long distances. Tracking studies and survey methods have revealed differences in winter migration routes among penguin species and colonies, dependent on both biotic and abiotic factors present. However, scan sampling methods are rarely used to reveal non-breeding behaviors during winter and little is known about presence at the colony site over this period. Here we show that Adélie penguins on the Yalour Islands in the Western Antarctic Peninsula (WAP) are present year-round at the colony and undergo a mid-winter peak in abundance during winter. We found a negative relationship between daylight hours and penguin abundance when either open water or compact ice conditions were present, suggesting that penguins return to the breeding colony when visibility is lowest for at-sea foraging and when either extreme low or high levels of sea ice exist offshore. In contrast, Adélie penguins breeding in East Antarctica were not observed at the colonies during winter, suggesting that Adélie penguins undergo differential winter strategies in the marginal ice zone on the WAP compared to those in East Antarctica. These results demonstrate that cameras can successfully monitor wildlife year-round in areas that are largely inaccessible during winter.

  6. Time-lapse imagery of Adélie penguins reveals differential winter strategies and breeding site occupation

    Science.gov (United States)

    Southwell, Colin; Emmerson, Louise; Lunn, Daniel

    2018-01-01

    Polar seabirds adopt different over-wintering strategies to survive and build condition during the critical winter period. Penguin species either reside at the colony during the winter months or migrate long distances. Tracking studies and survey methods have revealed differences in winter migration routes among penguin species and colonies, dependent on both biotic and abiotic factors present. However, scan sampling methods are rarely used to reveal non-breeding behaviors during winter and little is known about presence at the colony site over this period. Here we show that Adélie penguins on the Yalour Islands in the Western Antarctic Peninsula (WAP) are present year-round at the colony and undergo a mid-winter peak in abundance during winter. We found a negative relationship between daylight hours and penguin abundance when either open water or compact ice conditions were present, suggesting that penguins return to the breeding colony when visibility is lowest for at-sea foraging and when either extreme low or high levels of sea ice exist offshore. In contrast, Adélie penguins breeding in East Antarctica were not observed at the colonies during winter, suggesting that Adélie penguins undergo differential winter strategies in the marginal ice zone on the WAP compared to those in East Antarctica. These results demonstrate that cameras can successfully monitor wildlife year-round in areas that are largely inaccessible during winter. PMID:29561876

  7. Sea ice contribution to the air-sea CO(2) exchange in the Arctic and Southern Oceans

    DEFF Research Database (Denmark)

    Rysgaard...[], Søren; Bendtsen, Jørgen; Delille, B.

    2011-01-01

    Although salt rejection from sea ice is a key process in deep-water formation in ice-covered seas, the concurrent rejection of CO(2) and the subsequent effect on air-sea CO(2) exchange have received little attention. We review the mechanisms by which sea ice directly and indirectly controls the air......-sea CO(2) exchange and use recent measurements of inorganic carbon compounds in bulk sea ice to estimate that oceanic CO(2) uptake during the seasonal cycle of sea-ice growth and decay in ice-covered oceanic regions equals almost half of the net atmospheric CO(2) uptake in ice-free polar seas. This sea......-sea CO(2) exchange during winter, and (3) release of CO(2)-depleted melt water with excess total alkalinity during sea-ice decay and (4) biological CO(2) drawdown during primary production in sea ice and surface oceanic waters....

  8. Effects of different wavelengths of light on the biology, behavior, and production of grow-out Pekin ducks.

    Science.gov (United States)

    Campbell, C L; Colton, S; Haas, R; Rice, M; Porter, A; Schenk, A; Meelker, A; Fraley, S M; Fraley, G S

    2015-08-01

    Previous research has shown that red light conditions may improve growth and decrease aggressive behaviors in chickens and turkeys; however, more recent studies suggest that blue-green light may improve production of broilers over red light. To date, no research has been conducted to examine whether different wavelengths of light have an impact on production in the Pekin duck. To determine this, we raised Pekin ducks under aviary conditions that were similar to standard commercial barns. The ducks were kept in 3 different pens: red light (approximately 625 nm), blue light (approximately 425 nm), and white light. Light sources in each pen were standardized to produce a peak energy at 1.6 × 10³ μM photons/m²/s at the level of the ducks' heads. Ducks were given ad libitum access to water and commercial duck diet, and were housed on pine shavings at a density of 0.43 m²/duck. Ducks were evaluated weekly for BW and condition and a subjective measure of the duck's anxiety levels was determined. We found that ducks housed under blue light had significantly (P study (processing age; 35 d). Unlike ducks housed under red or white light, ducks housed in the blue pen showed a higher level of anxiety; while evaluators were in the pen a majority of them began panting, they were much less inquisitive than other ducks, they took longer to exhibit normal social behavior once evaluation was completed, and they frequently "swarmed" when no people were present. There were no differences in any measurements between the red and white-lighted pens. These data suggest that unlike the chicken, blue lights may be inappropriate for raising Pekin ducks in a commercial setting. © 2015 Poultry Science Association Inc.

  9. Thinking like a duck: fall lake use and movement patterns of juvenile ring-necked ducks before migration.

    Science.gov (United States)

    Roy, Charlotte L; Fieberg, John; Scharenbroich, Christopher; Herwig, Christine M

    2014-01-01

    The post-fledging period is one of the least studied portions of the annual cycle in waterfowl. Yet, recruitment into the breeding population requires that young birds have sufficient resources to survive this period. We used radio-telemetry and generalized estimating equations to examine support for four hypotheses regarding the drivers of landscape scale habitat use and movements made by juvenile ring-necked ducks between the pre-fledging period and departure for migration. Our response variables included the probability of movement, distances moved, and use of different lake types: brood-rearing lakes, staging lakes, and lakes with low potential for disturbance. Birds increased their use of staging areas and lakes with low potential for disturbance (i.e., without houses or boat accesses, >100 m from roads, or big lakes with areas where birds could sit undisturbed) throughout the fall, but these changes began before the start of the hunting season and their trajectory was not changed by the onset of hunting. Males and females moved similar distances and had similar probabilities of movements each week. However, females were more likely than males to use brood-rearing lakes later in the fall. Our findings suggest juvenile ring-necked ducks require different lake types throughout the fall, and managing solely for breeding habitat will be insufficient for meeting needs during the post-fledging period. Maintaining areas with low potential for disturbance and areas suitable for staging will ensure that ring-necked ducks have access to habitat throughout the fall.

  10. Death feigning by ducks in response to predation by red foxes (Vulpes fulva)

    Science.gov (United States)

    Sargeant, A.B.; Eberhardt, L.E.

    1975-01-01

    Predation by captive red foxes (Vulpes fulva) on approximately 50 ducks comprised of five species was observed in tests conducted at the Northern Prairie Wildlife Research Center, Jamestown, North Dakota. Most ducks were attacked from a rear or lateral position and seized in the cervical or thoracic region. All birds became immobile (death-feigned) immediately when seized and with few exceptions remained motionless during prey-handling and for varying lengths of time thereafter. Initial death feints lasted from 20 sec to 14 min. Recovery was delayed by tactile, visual and, possibly, auditory cues from the foxes. Death-feigning birds appeared alert and often took advantage of escape opportunities. Twenty-nine birds survived initial capture and handling by the foxes. Naive foxes were wary of ducks during initial confrontations, but experienced foxes showed little hesitation in attacking them. After capture, most ducks were taken alive to lay-down sites where they were mouthed and often killed. Then the ducks were usually cached or taken to dens or pups. Several birds were cached alive. Red foxes appear to have adapted to the escape of death-feigning ducks by learning to kill some birds soon after capture and by the evolution of an appendage-severing behavior. Death feigning appears to be a highly developed antipredator behavior of ducks that facilitates the escape of some birds after capture by red foxes.

  11. Optimizing the Performance of Solo Duck Wave Energy Converter in Tide

    Directory of Open Access Journals (Sweden)

    Jinming Wu

    2017-02-01

    Full Text Available The high efficiency performance of the Edinburgh Duck wave energy converter (WEC in 2D regular wave tests makes it a promising wave energy conversion scheme. A solo Duck WEC will be able to apply the point absorber effect to further enhance its performance. Since released degree of freedom will decrease the efficiency, a Duck WEC with fixed pitching axis will be a better option. However, for fixed supported WECs, tide is a non-ignorable consideration. In this paper, a movable mass method is utilized in the whole tidal range to not only balance the Duck to appropriate beak angles, but also follow the variation of hydrodynamic coefficients to keep cancelling the reactance of the system impedance so that complex conjugate control can be realized to optimize the power capture performance of the Duck WEC in tide. Results show that the beak angle should be adjusted to as large a value as possible so that the response amplitude of the Duck at maximum relative capture width will be reasonable small, and the lowest weight of the movable mass is found when its designed position locates at the center of the Duck profile.

  12. Mitochondrial D-loop sequence of domesticated waterfowl in Central Java: goose and muscovy duck

    Science.gov (United States)

    Susanti, R.; Iswari, R. S.

    2018-03-01

    This study aims to determine the genetic characterization of domesticated waterfowl (goose and Muscovy duck) in Central Java based on a D-loop mtDNA gene. The D-loop gene was amplified using PCR technique by specific primer and sequenced using dideoxy termination method. Multiple alignments of D-loop gene obtained were 710 nucleotides at position 74 to 783 at the 5’ end (for goose) and 712 nucleotides at position 48 to 759 at the 5’ end (for Muscovy duck). The results of the polymorphism analysis on D-loop sequences of muscovy duck produced 3 haplotypes. In the D-loop gene of goose does not show polymorphism, with substitution at G117A. Phylogenetic trees reconstructions of goose and Muscovy duck, which was collected during this research compared with another species from Anser, Chairina and Anas was generated 2 forms of clusters. The first group consists of all kind of Muscovy duck together with Chairina moschata and Anas, while the second group consists of all geese and Anser cygnoides the other. The determination of Muscovy duck and geese identity can be distinguished from the genetic marker information. Based on the phylogenetic analysis, it can be concluded that the Muscovy duck is closely related to Chairina moschata, while geese is closely related to Anser cygnoides.

  13. Detection and molecular characterization of J subgroup avian leukosis virus in wild ducks in China.

    Science.gov (United States)

    Zeng, Xiangwei; Liu, Lanlan; Hao, Ruijun; Han, Chunyan

    2014-01-01

    To assess the status of avian leukosis virus subgroup J (ALV-J) in wild ducks in China, we examined samples from 528 wild ducks, representing 17 species, which were collected in China over the past 3 years. Virus isolation and PCR showed that 7 ALV-J strains were isolated from wild ducks. The env genes and the 3'UTRs from these isolates were cloned and sequenced. The env genes of all 7 wild duck isolates were significantly different from those in the prototype strain HPRS-103, American strains, broiler ALV-J isolates and Chinese local chicken isolates, but showed close homology with those found in some layer chicken ALV-J isolates and belonged to the same group. The 3'UTRs of 7 ALV-J wild ducks isolates showed close homology with the prototype strain HPRS-103 and no obvious deletion was found in the 3'UTR except for a 1 bp deletion in the E element that introduced a binding site for c-Ets-1. Our study demonstrated the presence of ALV-J in wild ducks and investigated the molecular characterization of ALV-J in wild ducks isolates.

  14. Evaluation of chlorpyrifos transferred from contaminated feed to duck commodities and dietary risks to Chinese consumers.

    Science.gov (United States)

    Li, Rui; Ji, Xiaofeng; He, Liang; Liu, Zhiqiang; Wei, Wei; Qiang, Mingrong; Wang, Qiang; Yuan, Yuwei

    2015-06-03

    The present study describes chlorpyrifos residues in duck commodities through the duck food chain, transfer factors, and dietary risks to Chinese consumers. After duck feeding experiments with pellet feed that lasted for 42 days, chlorpyrifos residues found in all samples collected from the ducks on maximum estimated dose group (3.20 mg/kg level) were from chlorpyrifos had a low persistency in duck meat and metabolism organs. The chronic exposure assessment revealed that only 0.034-0.150% of the acceptable daily intake (ADI; 0-0.01 mg/kg/bw/day) of chlorpyrifos was consumed via the duck commodities for different age and gender groups in China. The acute exposure assessments of different age and gender groups were only 0.019-0.082% of the acute reference dose (ARfD; 0-0.1 mg/kg/bw). The results show that the single dietary exposure risk of chlorpyrifos raised by the intake of duck commodities was quite low in China.

  15. Advertising displays of male Musk Ducks indicate population subdivision across the Nullarbor Plain of Australia

    Science.gov (United States)

    McCracken, K.G.; Fullagar, P.J.; Slater, E.C.; Paton, D.C.; Afton, A.D.

    2002-01-01

    Acoustic advertising displays (n=75) of male Musk Ducks Biziura lobata were analysed at ten widely spaced geographic localities in South Australia, Victoria, and Western Australia. Vocalisations differed in a fixed, non-overlapping pattern between allopatric Musk Duck populations in southeastern and southwestern Australia. These findings suggest that Musk Duck populations are subdivided by the Nullarbor Plain, the arid treeless desert at the head of the Great Australian Bight. Three vocalisations performed by male Musk Ducks not previously reported in the literature were documented also. Vocalisations of captive Musk Ducks collected from different geographic regions (southeast and southwest) differed between regions from which captives originally were collected and were unlike those performed by wild birds. Based on calls of immature Musk Ducks, acoustic variation within regional populations and the apparent inability of captive Musk Ducks reared in isolation to develop the wild type adult call, regional dialects seemingly are acquired in a social context by repeated observance of adult males and some combination of social imprinting, learning, or practice.

  16. Duck egg-drop syndrome caused by BYD virus, a new Tembusu-related flavivirus.

    Directory of Open Access Journals (Sweden)

    Jingliang Su

    Full Text Available Since April 2010, a severe outbreak of duck viral infection, with egg drop, feed uptake decline and ovary-oviduct disease, has spread around the major duck-producing regions in China. A new virus, named BYD virus, was isolated in different areas, and a similar disease was reproduced in healthy egg-producing ducks, infecting with the isolated virus. The virus was re-isolated from the affected ducks and replicated well in primary duck embryo fibroblasts and Vero cells, causing the cytopathic effect. The virus was identified as an enveloped positive-stranded RNA virus with a size of approximately 55 nm in diameter. Genomic sequencing of the isolated virus revealed that it is closely related to Tembusu virus (a mosquito-borne Ntaya group flavivirus, with 87-91% nucleotide identity of the partial E (envelope proteins to that of Tembusu virus and 72% of the entire genome coding sequence with Bagaza virus, the most closely related flavivirus with an entirely sequenced genome. Collectively our systematic studies fulfill Koch's postulates, and therefore, the causative agent of the duck egg drop syndrome occurring in China is a new flavivirus. Flavivirus is an emerging and re-emerging zoonotic pathogen and BYD virus that causes severe egg-drop, could be disastrous for the duck industry. More importantly its public health concerns should also be evaluated, and its epidemiology should be closely watched due to the zoonotic nature of flaviviruses.

  17. Hemato-biochemical and pathological changes on avian influenza in naturally infected domestic ducks in Egypt

    Directory of Open Access Journals (Sweden)

    Essam A. Mahmoud

    2015-10-01

    Full Text Available Aim: Few studies have been made in regard to avian influenza (AI in ducks, thus the aim of this work was planned to investigate the hematological, biochemical, and pathological changes in domestic Egyptian ducks naturally infected with AI. Materials and Methods: 30 duck from private backyards 3-month-old 15 were clinically healthy (Group 1 and the other fifteen (Group 2 were naturally diseased with AI (H5N1. The disease was diagnosed by polymerase chain reaction as H5N1. Results: Duck showed cyanosis, subcutaneous edema of head and neck with nervous signs (torticollis. Hematological studies revealed a microcytic hypochromic anemia. Biochemical studies revealed a significant decrease in total protein, albumin and globulin concentration with significant increase of activities of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, Υ-glutamyl transpeptidase, lactic acid dehydrogenase and creatine phsphokinase. Prominent increase in creatinine and uric acid in addition to hypocalcemia and hyperphosphatemia were significantly detected in the infected ducks. Histopathological finding confirm these investigations. Conclusion: The highly pathogenic AIV (A/H5N1 became more severe infectious to ducks than before and causes nervous manifestations and blindness which were uncommon in ducks. Besides the significant increases of hepatic enzymes, brain, heart, and renal markers as a response to virus damage to these organs.

  18. Morphometric Traits of Muscovy Ducks from Two Agro Ecological Zones of Nigeria

    Directory of Open Access Journals (Sweden)

    Yakubu, A.

    2011-01-01

    Full Text Available Morphological variation between Muscovy ducks from the guinea savannah and rainforest zones of Nigeria was examined using multivariate discriminant analysis. Data comprised eight morphometric traits measured in a total of 435 adult ducks randomly selected in the two agro-ecological zones. Common descriptive statistics showed that ducks from the rainforest zone had higher (P< 0.05 body weight, foot length and thigh circumference, while their guinea savannah counterparts were longer (P< 0.05 in the neck. Stepwise discriminant analysis indicated that foot length, neck length, thigh circumference and body length were more effective in discriminating between the duck populations. The low Mahalanobis distance of 3.39, as revealed by the canonical discriminant analysis, is an indication of high gene flow between ducks from the two agro-ecological zones. The cluster analysis also revealed the homogeneity of the genetic identity of the duck populations. The present information will be the basis for further characterization, conservation and sustainable genetic improvement strategies for indigenous ducks.

  19. Effect of Bacillus subtilis natto on growth performance in Muscovy ducks

    Directory of Open Access Journals (Sweden)

    T Sheng-Qiu

    2013-09-01

    Full Text Available The aim of the present study was to determine whether dietary Bacillus subtilis natto could affect growth performance of Muscovy ducks. A total of 120 hundred Muscovy ducks at the age of 1 day were randomly assigned to four groups (30 Muscovy ducks/group, and fed with diets supplemented with 0% (control group, 0.1%, 0.2%, and 0.4% Bacillus subtilis natto, respectively during the 6-week feeding period. Weight gain, feed intake and feed conversion efficiency of Muscovy ducks were significantly improved by the dietary addition of Bacillus subtilis natto, and the results were more significant in 0.4% dietary Bacillus subtilis natto treatment group; Also, Bacillus subtilis natto reduced Escherichia coli and Salmonella colonies, and increased lactobacilli population in the ileum and the cecum. Biochemical parameters, including total protein, GOT (glutamic oxaloacetic transaminase, GPT (glutamic pyruvic transaminase, AKP (alkaline phosphatase, triiodothyronine (T3 and tetraiodothyronine (T4 contents (pBacillus subtilis natto was added to the diets (p0.05. The results of the present study indicate that diets with 0.4% Bacillus subtilis natto improved the growth performance of Muscovy ducks by increasing the absorption of protein, simulating hormone secretion, suppressing harmful microflora, and improving the duodenal structure and immune functions of Muscovy ducks. It is suggested that Bacillus subtilis natto is a potential candidate to be used use as a probiotic to improve the growth performance of Muscovy ducks.

  20. Observational analysis of air-sea fluxes and sea water temperature offshore South China Sea

    Science.gov (United States)

    Bi, X.; Huang, J.; Gao, Z.; Liu, Y.

    2017-12-01

    This paper investigates the air-sea fluxes (momentum flux, sensible heat flux and latent heat flux) from eddy covariance method based on data collected at an offshore observation tower in the South China Sea from January 2009 to December 2016 and sea water temperature (SWT) on six different levels based on data collected from November 2011 to June 2013. The depth of water at the tower over the sea averages about 15 m. This study presents the in-situ measurements of continuous air-sea fluxes and SWT at different depths. Seasonal and diurnal variations in air-sea fluxes and SWT on different depths are examined. Results show that air-sea fluxes and all SWT changed seasonally; sea-land breeze circulation appears all the year round. Unlike winters where SWT on different depths are fairly consistent, the difference between sea surface temperature (SST) and sea temperature at 10 m water depth fluctuates dramatically and the maximum value reaches 7 °C during summer.

  1. Analysis of the Warmest Arctic Winter, 2015-2016

    Science.gov (United States)

    Cullather, Richard I.; Lim, Young-Kwon; Boisvert, Linette N.; Brucker, Ludovic; Lee, Jae N.; Nowicki, Sophie M. J.

    2016-01-01

    December through February 2015-2016 defines the warmest winter season over the Arctic in the observational record. Positive 2m temperature anomalies were focused over regions of reduced sea ice cover in the Kara and Barents Seas and southwestern Alaska. A third region is found over the ice-covered central Arctic Ocean. The period is marked by a strong synoptic pattern which produced melting temperatures in close proximity to the North Pole in late December and anomalous high pressure near the Taymyr Peninsula. Atmospheric teleconnections from the Atlantic contributed to warming over Eurasian high-latitude land surfaces, and El Niño-related teleconnections explain warming over southwestern Alaska and British Columbia, while warm anomalies over the central Arctic are associated with physical processes including the presence of enhanced atmospheric water vapor and an increased downwelling longwave radiative flux. Preconditioning of sea ice conditions by warm temperatures affected the ensuing spring extent.

  2. Characterization of nasal cavity-associated lymphoid tissue in ducks.

    Science.gov (United States)

    Kang, Haihong; Yan, Mengfei; Yu, Qinghua; Yang, Qian

    2014-05-01

    The nasal mucosa is involved in immune defense, as it is the first barrier for pathogens entering the body through the respiratory tract. The nasal cavity-associated lymphoid tissue (NALT), which is found in the mucosa of the nasal cavity, is considered to be the main mucosal immune inductive site in the upper respiratory tract. NALT has been found in humans and many mammals, which contributes to local and systemic immune responses after intranasal vaccination. However, there are very few data on NALT in avian species, especially waterfowl. For this study, histological sections of the nasal cavities of Cherry Valley ducks were used to examine the anatomical location and histological characteristics of NALT. The results showed that several lymphoid aggregates are present in the ventral wall of the nasal cavity near the choanal cleft, whereas several more lymphoid aggregates were located on both sides of the nasal septum. In addition, randomly distributed intraepithelial lymphocytes and isolated lymphoid follicles were observed in the regio respiratoria of the nasal cavity. There were also a few lymphoid aggregates located in the lamina propria of the regio vestibularis, which was covered with a stratified squamous epithelium. This study focused on the anatomic and histological characteristics of the nasal cavity of the duck and performed a systemic overview of NALT. This will be beneficial for further understanding of immune mechanisms after nasal vaccination and the development of effective nasal vaccines for waterfowls. Copyright © 2014 Wiley Periodicals, Inc.

  3. Transcriptome analysis of adiposity in domestic ducks by transcriptomic comparison with their wild counterparts.

    Science.gov (United States)

    Chen, L; Luo, J; Li, J X; Li, J J; Wang, D Q; Tian, Y; Lu, L Z

    2015-06-01

    Excessive adiposity is a major problem in the duck industry, but its molecular mechanisms remain unknown. Genetic comparisons between domestic and wild animals have contributed to the exploration of genetic mechanisms responsible for many phenotypic traits. Significant differences in body fat mass have been detected between domestic and wild ducks. In this study, we used the Peking duck and Anas platyrhynchos as the domestic breed and wild counterpart respectively and performed a transcriptomic comparison of abdominal fat between the two breeds to comprehensively analyze the transcriptome basis of adiposity in ducks. We obtained approximately 350 million clean reads; assembled 61 250 transcripts, including 23 699 novel ones; and identified alternative 5' splice sites, alternative 3' splice sites, skipped exons and retained intron as the main alternative splicing events. A differential expression analysis between the two breeds showed that 753 genes exhibited differential expression. In Peking ducks, some lipid metabolism-related genes (IGF2, FABP5, BMP7, etc.) and oncogenes (RRM2, AURKA, CYR61, etc.) were upregulated, whereas genes related to tumor suppression and immunity (TNFRSF19, TNFAIP6, IGSF21, NCF1, etc.) were downregulated, suggesting adiposity might closely associate with tumorigenesis in ducks. Furthermore, 280 576 single-nucleotide variations were found differentiated between the two breeds, including 8641 non-synonymous ones, and some of the non-synonymous ones were found enriched in genes involved in lipid-associated and immune-associated pathways, suggesting abdominal fat of the duck undertakes both a metabolic function and immune-related function. These datasets enlarge our genetic information of ducks and provide valuable resources for analyzing mechanisms underlying adiposity in ducks. © 2015 Stichting International Foundation for Animal Genetics.

  4. A comparison of long bone development in historical and contemporary ducks.

    Science.gov (United States)

    Van Wyhe, R C; Applegate, T J; Lilburn, M S; Karcher, D M

    2012-11-01

    The selection for growth and carcass traits in poultry meat species has contributed to increased interest in understanding and characterizing skeletal growth as the birds struggle to balance skeletal development with increased BW and muscle mass. The objective of this study was to compare the physical characteristics and mineralization of the tibia and femur from commercial Pekin ducks representing circa 1993 and 2010 commercial strains. In 1993, the femur and tibia were collected from 8 ducks at 11 ages between 11 and 53 d. A similar study was done in 2010 in which the femur and tibia were collected from 8 ducks at 12 sample ages between 10 and 49 d. All bones were weighed and the length and width at 50% of length were measured. Each bone was subsequently cut into epiphyseal (top 25% of length) and diaphyseal (midregion at 50% of length) sections. Each bone segment was extracted with ether, hot weighed, and ashed. The 2010 contemporary ducks reached market weight faster than the 1993 ducks. Therefore, statistical comparisons were made at common BW as well as at common ages. The mean tibia length of the 2010 duck was 0.75 cm greater (P ducks. The percentage epiphyseal ash in the femur was 10% lower (P ducks but there were no significant differences by 18 d of age. The lower epiphyseal ash values at both younger ages and smaller BW in the 2010 contemporary ducks suggests that it is critical to monitor those factors that influence bone mineralization in contemporary ducklings that can achieve market BW at earlier chronological ages.

  5. Penggantian Sebagian Ransum Komersial dengan Polar dan Aditif Duck mix terhadap Komposisi Fisik Karkas Itik

    Directory of Open Access Journals (Sweden)

    Ni Wayan Siti

    2009-10-01

    Full Text Available The substitution a part of commercial feed with pollard and duck mix additive on duck carcass physic composition ABSTRACT. The aim of this experiment was to study pollard optimum levels with additive complex mineral vitamin on the carcass physic composition Balinese male duck age 10 weeks, was carried out at Jl. Binginambe, Kediri village, Tabanan Regency. The design which used in this experiment a completely randomized design Those four treatments were ration contain 100% commercial feed (A; ration with 85% commercial feed + 15% pollard + 0,3% duck mix (B; ration with 70% commercial feed + 30% pollard + 0,3% duck mix (C; ration with 55% commercial feed + 45% pollard + 0,3% duck mix (D, respectively. The variables which measured were carcass weight, carcass percent, and carcass physic composition. The result of this experiment showed that the substitution commercial feed with pollard from 15-45% and duck mix were not significant (P >0.05 decrease carcass percent, carcass bone percent than treatment A. Meat percent on treatment B 1.81% non significant (P>0.05 increase than treatment A, but C and D treatments 2.63% and 4.87% significantly increase than treatment A. Subcutan fat on C and D treatments 6.72% and 6.67% significant lower (P <0.05 than treatment A, and D treatment 4.91% significant lower than treatment B. From the result of this experiment can be concluded that substitution pollard from 15%-45% with additive 0.3% duck mix were decrease carcass percent and bone carcass percent, but substitution pollard 30% and 45% can increase meat carcass percent and decrease fat Balinese male duck age 10 weeks.

  6. Accumulation and elimination of polychlorinated dibenzo-p-dioxins and dibenzofurans in mule ducks

    International Nuclear Information System (INIS)

    Wu, Ting-Wei; Lee, Jai-Wei; Liu, Hsueh-Yen; Lin, Wei-Hsiao; Chu, Chun-Yen; Lin, Sheng-Lun; Chang-Chien, Guo Ping; Yu, Chi

    2014-01-01

    In Taiwan, a food safety crisis involving a presence of high concentrations of dioxin residues in duck eggs occurred in 2004. The dioxin content in duck meat sampled from supermarkets was also reported to be substantially higher than in products from other farm animals. Despite increased awareness of the potential for contamination and exposure to dioxins, the accumulation and elimination of dioxins in ducks have not been well characterized. In the present study, mule ducks were fed capsules containing polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) for 14 days and the trial was continued for another 28 days without PCDD/Fs supplementation. Ducks were sacrificed on the 14th, 28th, and 42nd days from the beginning of administration and samples of abdominal fat, breast, and liver tissue were obtained. The concentrations of PCDD/Fs were analyzed in the samples to investigate their distribution and elimination in various duck tissues. The bioaccumulation of PCDD/Fs in ducks was found to be tissue-dependent. In the abdominal fat, the bioconcentration factor was negatively correlated with the degree of chlorination. Conversely, more chlorinated PCDD/Fs (hexa- or hepta-congeners) were associated with higher bioconcentration in the liver and breast tissue. In terms of the efficiency of PCDD/Fs elimination, the liver was found to be the fastest, followed by the breast and the abdominal fat. The clearance rate positively correlated with the degree of chlorination, as determined by comparing the apparent elimination rate constant (k) of PCDD/Fs in various tissues. Overall, lower k values observed in this study imply that mule ducks have a reduced clearance of PCDD/Fs in comparison with layer and broiler chickens. - Highlights: • We describe the accumulation and elimination of PCDD/Fs in mule ducks. • The accumulation of PCDD/Fs in mule ducks was tissue-specific. • The elimination of PCDD/Fs in tissues of mule ducks was congener-specific. • The

  7. Ecology of fall-migrating ducks in central Illinois: A radar perspective

    Science.gov (United States)

    O'Neal, Benjamin J.

    Research from the last two decades has elucidated the importance of migration in the annual cycle of ducks, but many aspects of migration ecology remain poorly understood due to the difficulty of investigating movements that occur over large spatial scales, at substantial heights and at night. Weather surveillance radar (WSR) offers a unique tool for observing movements of birds aloft, but until now has been used primarily to address questions only relevant to broad taxonomic groups. Using thermal infrared imaging, portable radar, and natural history, I ground-truthed WSR echoes originating from a complex of wetlands in the central Illinois River valley to develop a technique for identifying and enumerating ducks as they emigrated from this important stopover area. With this technique, I quantified duck emigrations during 7 falls (1996, 1997, 2003, and 2005-2008). I used WSR-derived estimates of annual turnover in combination with aerial inventory estimates of duck use to estimate the average amount of time ducks spent at my study site during fall (stopover duration). The mean stopover duration estimate of 11 days (SD = 4 days) was much shorter than a historical estimate (28 days) that has been use for regional waterfowl conservation planning. I also regressed average annual stopover duration estimates against an index of annual foraging habitat quality and found a strong, positive relationship (r2 = 0.71), suggesting ducks assessed local habitat conditions and adjusted time spent at the site. Weather influences the timing of migration in many avian taxa, but this relationship is poorly understood for ducks. An evaluation of competing models including 15 years of data indicated following winds aloft, no precipitation, less cloud cover, decreasing temperatures, increasing barometric pressure and date best predicted emigration (R2 = 0.52). Based on this model, the odds of a duck emigration occurring when winds were following and precipitation was absent were 13.2 to

  8. Plasma corticosterone and thyroxine concentrations during chronic ingestion of crude oil in mallard ducks (Anas platyrhynchos)

    Science.gov (United States)

    Rattner, B.A.; Eastin, W.C.

    1981-01-01

    1. Blood samples were collected from mallard ducks after 6, 12, and 18 weeks of dietary exposure to mash containing 0.015%, 0.150%, and 1.500% crude oil.2. Plasma corticosterone concentrations in ducks fed mash containing 0.150% or 1.500% Alaskan Prudhoe Bay crude oil were uniformly depressed when compared to values in untreated control birds.3. Plasma thyroxine concentration was not altered in ducks chronically exposed to crude oil.4. The observed alteration in corticosterone concentration could reduce tolerance to temperature and dietary fluctuations in the environment.

  9. MARKETING STRATEGY FOR START UP BUSINESS OF BROILER PEKING DUCK FARM WITH ECO-GREEN INTEGRATED

    OpenAIRE

    Silitonga N.; Syah T.Y.R.; Erni N.

    2018-01-01

    The increasing number and the rate of Banten population growth from year to year make it as a potential market which is quite large for the development of broiler duck farming business in the future. In this case, intensive system broiler Peking duck farming which is integrated, economic, and eco-green intensive, eco-green commonly utilizes Azolla microphylla and flour of pluchea leaves and other germ plasmas as the feed supplements. As a company in Peking duck farming with Eco Green concept,...

  10. Accumulation and elimination of polychlorinated dibenzo-p-dioxins and dibenzofurans in mule ducks

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Ting-Wei, E-mail: M10126010@mail.npust.edu.tw [Department of Animal Science, National Pingtung University of Science Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan (China); Lee, Jai-Wei, E-mail: joeylee@mail.npust.edu.tw [Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan (China); Liu, Hsueh-Yen, E-mail: M9926012@mail.npust.edu.tw [Department of Animal Science, National Pingtung University of Science Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan (China); Lin, Wei-Hsiao, E-mail: M10126011@mail.npust.edu.tw [Department of Animal Science, National Pingtung University of Science Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan (China); Chu, Chun-Yen, E-mail: cychu@mail.npust.edu.tw [Graduate Institute of Animal Vaccine Technology, National Pingtung University of Science Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan (China); Lin, Sheng-Lun, E-mail: sllin100@csu.edu.tw [Supermicro Mass Research and Technology Center, Cheng Shiu University, No. 840, Chengcing Road, Niaosong Dist., Kaohsiung City 83347, Taiwan (China); Center for General Education, Cheng Shiu University, No. 840, Chengcing Road, Niaosong Dist., Kaohsiung City 83347, Taiwan (China); Chang-Chien, Guo Ping, E-mail: guoping@csu.edu.tw [Supermicro Mass Research and Technology Center, Cheng Shiu University, No. 840, Chengcing Road, Niaosong Dist., Kaohsiung City 83347, Taiwan (China); Department of Cosmetics and Fashion styling, Cheng Shiu University, No. 840, Chengcing Road, Niaosong Dist., Kaohsiung City 83347, Taiwan (China); Yu, Chi, E-mail: chiyu@mail.npust.edu.tw [Department of Animal Science, National Pingtung University of Science Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan (China)

    2014-11-01

    In Taiwan, a food safety crisis involving a presence of high concentrations of dioxin residues in duck eggs occurred in 2004. The dioxin content in duck meat sampled from supermarkets was also reported to be substantially higher than in products from other farm animals. Despite increased awareness of the potential for contamination and exposure to dioxins, the accumulation and elimination of dioxins in ducks have not been well characterized. In the present study, mule ducks were fed capsules containing polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) for 14 days and the trial was continued for another 28 days without PCDD/Fs supplementation. Ducks were sacrificed on the 14th, 28th, and 42nd days from the beginning of administration and samples of abdominal fat, breast, and liver tissue were obtained. The concentrations of PCDD/Fs were analyzed in the samples to investigate their distribution and elimination in various duck tissues. The bioaccumulation of PCDD/Fs in ducks was found to be tissue-dependent. In the abdominal fat, the bioconcentration factor was negatively correlated with the degree of chlorination. Conversely, more chlorinated PCDD/Fs (hexa- or hepta-congeners) were associated with higher bioconcentration in the liver and breast tissue. In terms of the efficiency of PCDD/Fs elimination, the liver was found to be the fastest, followed by the breast and the abdominal fat. The clearance rate positively correlated with the degree of chlorination, as determined by comparing the apparent elimination rate constant (k) of PCDD/Fs in various tissues. Overall, lower k values observed in this study imply that mule ducks have a reduced clearance of PCDD/Fs in comparison with layer and broiler chickens. - Highlights: • We describe the accumulation and elimination of PCDD/Fs in mule ducks. • The accumulation of PCDD/Fs in mule ducks was tissue-specific. • The elimination of PCDD/Fs in tissues of mule ducks was congener-specific. • The

  11. Novel genetic markers of the carbonic anhydrase II gene associated with egg production and reproduction traits in Tsaiya ducks.

    Science.gov (United States)

    Chang, M-T; Cheng, Y-S; Huang, M-C

    2013-02-01

    In our previous cDNA microarray study, we found that the carbonic anhydrase II (CA2) gene is one of the differentially expressed transcripts in the duck isthmus epithelium during egg formation period. The aim of this study was to identify the single-nucleotide polymorphisms (SNPs) in the CA2 gene of Tsaiya ducks. The relationship of SNP genotype with egg production and reproduction traits was also investigated. A total of 317 ducks from two lines, a control line with no selection and a selected line, were employed for testing. Three SNPs (C37T, A62G and A65G) in the 3'-untranslated region of the CA2 gene were found. SNP-trait association analysis showed that SNP C37T and A62G were associated with duck egg weight besides fertility. The ducks with the CT and AG genotypes had a 1.46 and 1.62 g/egg lower egg weight as compared with ducks with the CC and AA genotypes, respectively (p ducks with CT and AG genotypes had 5.20% and 4.22% higher fertility than those with CC and AA genotypes, respectively (p duck fertility, and the diplotype H1H4 was dominant for duck fertility. These findings might provide the basis for balanced selection and may be used in marker-assisted selection to improve egg weight and fertility simultaneously in the Tsaiya ducks. © 2012 Blackwell Verlag GmbH.

  12. Genomic and pathogenic analysis of a Muscovy duck parvovirus strain causing short beak and dwarfism syndrome without tongue protrusion.

    Science.gov (United States)

    Fu, Qiuling; Huang, Yu; Wan, Chunhe; Fu, Guanghua; Qi, Baomin; Cheng, Longfei; Shi, Shaohua; Chen, Hongmei; Liu, Rongchang; Chen, Zhenhai

    2017-12-01

    In 2008, clinical cases of short beak and dwarfism syndrome (SBDS) caused by Muscovy duck parvovirus (MDPV) infection were found in mule duck and Taiwan white duck farms in Fujian, China. A MDPV LH strain causing duck SBDS without tongue protrusion was isolated in this study. Phylogenetic analysis show that the MDPV LH strain was clustered together with other MDPV strains, but divergent from GPV isolates. Two major fragment deletions were found in the inverted terminal repeats (ITR) of MDPV LH similar to the ones in the ITR of MDPV GX5, YY and SAAS-SHNH strains. To investigate the pathogenicity of the MDPV LH strain, virus infection of young mule ducks was performed. The infected ducks showed SBDS symptoms including retard growth and shorten beaks without tongue protrusion. Atrophy of thymus, spleen and bursa of Fabricius was identified in the infected ducks. The results show that MDPV LH strain is moderately pathogenic to mule duck, leading to occurrence of SBDS. As far as we know, it is the first study showing that SBDS without tongue protrusion, and atrophy of thymus, spleen and bursa of Fabricius possibly associated with immunosuppression were found in the MDPV-infected ducks. The established duck-MDPV-SBDS system will help us to further work on the virus pathogenesis and develop efficacious vaccine against MDPV infection. Copyright © 2017. Published by Elsevier Ltd.

  13. Concentrations of cadmium, mercury and selenium in common eider ducks in the eastern Canadian arctic: Influence of reproductive stage

    International Nuclear Information System (INIS)

    Wayland, Mark; Gilchrist, H. Grant; Neugebauer, Ewa

    2005-01-01

    Concentrations and total organ content of mercury, selenium and cadmium, as well as liver, kidney and body mass were determined in female common eiders from 1997 to 2000 at the East Bay Migratory Bird Sanctuary in the eastern Canadian arctic. In 1997 and 1999, female eiders were collected during the pre-nesting period when they eat copious amounts of food and gain substantial weight in preparation for the rigours of nesting. In 1998 and 1999, female eiders were collected during the mid to late stages of the nesting period when they eat very little, if at all, and, as a consequence undergo dramatic weight loss. Total body mass, liver mass and kidney mass were highest in pre-nesting birds, especially in 1997. They were significantly lower in nesting birds collected in 1998 and 2000. In contrast, mercury and cadmium concentrations were lowest in pre-nesting birds collected in 1997 and 1999 and increased to significantly higher concentrations in nesting birds collected in 1998 and 2000. In contrast to these results, the total contents of mercury in liver and cadmium in kidney did not change significantly over the 4-year period. Hepatic selenium concentrations were relatively stable over the 4-year study period while changes in the total content of selenium in the liver paralleled changes in liver mass and body mass. The results suggest that mercury and cadmium concentrations in female common eiders change in response to normal changes in body and organ mass that occur during the reproductive period. Thus, it may be important to consider body condition or reproductive stage when using common eiders (and perhaps other species of sea ducks) in biomonitoring studies or when interpreting concentrations of metals in tissues in terms of the risk they pose to these ducks

  14. Concentrations of cadmium, mercury and selenium in common eider ducks in the eastern Canadian arctic: influence of reproductive stage.

    Science.gov (United States)

    Wayland, Mark; Gilchrist, H Grant; Neugebauer, Ewa

    2005-12-01

    Concentrations and total organ content of mercury, selenium and cadmium, as well as liver, kidney and body mass were determined in female common eiders from 1997 to 2000 at the East Bay Migratory Bird Sanctuary in the eastern Canadian arctic. In 1997 and 1999, female eiders were collected during the pre-nesting period when they eat copious amounts of food and gain substantial weight in preparation for the rigours of nesting. In 1998 and 1999, female eiders were collected during the mid to late stages of the nesting period when they eat very little, if at all, and, as a consequence undergo dramatic weight loss. Total body mass, liver mass and kidney mass were highest in pre-nesting birds, especially in 1997. They were significantly lower in nesting birds collected in 1998 and 2000. In contrast, mercury and cadmium concentrations were lowest in pre-nesting birds collected in 1997 and 1999 and increased to significantly higher concentrations in nesting birds collected in 1998 and 2000. In contrast to these results, the total contents of mercury in liver and cadmium in kidney did not change significantly over the 4-year period. Hepatic selenium concentrations were relatively stable over the 4-year study period while changes in the total content of selenium in the liver paralleled changes in liver mass and body mass. The results suggest that mercury and cadmium concentrations in female common eiders change in response to normal changes in body and organ mass that occur during the reproductive period. Thus, it may be important to consider body condition or reproductive stage when using common eiders (and perhaps other species of sea ducks) in biomonitoring studies or when interpreting concentrations of metals in tissues in terms of the risk they pose to these ducks.

  15. Concentrations of cadmium, mercury and selenium in common eider ducks in the eastern Canadian arctic: Influence of reproductive stage

    Energy Technology Data Exchange (ETDEWEB)

    Wayland, Mark [Environment Canada, Prairie and Northern Wildlife Research Centre, 115 Perimeter Rd., Saskatoon, SK, S7N 0X4 (Canada)]. E-mail: mark.wayland@ec.gc.ca; Gilchrist, H. Grant [Canadian Wildlife Service, Prairie and Northern Region, Suite 301, 5204-50th St., Yellowknife, NT, X1A 1E2 (Canada); Neugebauer, Ewa [Environment Canada, National Wildlife Research Centre, Carleton University, 1125 Colonel By Dr., Ottawa, ON, K1S 5B6 (Canada)

    2005-12-01

    Concentrations and total organ content of mercury, selenium and cadmium, as well as liver, kidney and body mass were determined in female common eiders from 1997 to 2000 at the East Bay Migratory Bird Sanctuary in the eastern Canadian arctic. In 1997 and 1999, female eiders were collected during the pre-nesting period when they eat copious amounts of food and gain substantial weight in preparation for the rigours of nesting. In 1998 and 1999, female eiders were collected during the mid to late stages of the nesting period when they eat very little, if at all, and, as a consequence undergo dramatic weight loss. Total body mass, liver mass and kidney mass were highest in pre-nesting birds, especially in 1997. They were significantly lower in nesting birds collected in 1998 and 2000. In contrast, mercury and cadmium concentrations were lowest in pre-nesting birds collected in 1997 and 1999 and increased to significantly higher concentrations in nesting birds collected in 1998 and 2000. In contrast to these results, the total contents of mercury in liver and cadmium in kidney did not change significantly over the 4-year period. Hepatic selenium concentrations were relatively stable over the 4-year study period while changes in the total content of selenium in the liver paralleled changes in liver mass and body mass. The results suggest that mercury and cadmium concentrations in female common eiders change in response to normal changes in body and organ mass that occur during the reproductive period. Thus, it may be important to consider body condition or reproductive stage when using common eiders (and perhaps other species of sea ducks) in biomonitoring studies or when interpreting concentrations of metals in tissues in terms of the risk they pose to these ducks.

  16. Trade patterns facilitating highly pathogenic avian influenza virus dissemination in the free-grazing layer duck system in Vietnam.

    Science.gov (United States)

    Meyer, A; Dinh, T X; Han, T A; Do, D V; Nhu, T V; Pham, L T; Nguyen, T T T; Newman, S; Häsler, B; Pfeiffer, D U; Vergne, T

    2018-04-01

    Highly pathogenic avian influenza (HPAI) viruses continue to threaten smallholder poultry producers in several South-east Asian countries, including Vietnam. In particular, the free-grazing duck system has been repeatedly highlighted as a major risk factor for HPAI outbreaks. Free-grazing ducks, which scavenge on rice paddies after the harvest, account for a large proportion of the duck population in Vietnam and the wider South-east Asian region. However, the structure and dynamics of the free-grazing duck production from farm to consumption has not been described for Vietnam. In this study, we used a value chain approach to provide a complete picture of the actors involved in the production and marketing of free-grazing duck eggs and spent layer ducks, as well as to investigate the governance structure of this food system. Group interviews and key informant interviews were conducted in two provinces located in the Mekong River Delta (MRD) and the Red River Delta (RRD). The results presented here highlight similarities and differences in farming and trade practices between the two provinces. The trade of spent layer ducks involved large volumes of live ducks being sent to China and Cambodia for consumption, generating a substantial risk of transboundary spread of pathogens, including HPAI viruses. We describe the major role of "duck yards", which act as hubs in the northbound trade of spent layer ducks. These yards should be considered as essential links in the value chain of spent layer ducks when considering HPAI surveillance and control. The veterinary authorities are only marginally involved in the value chain activities, and their influence could be strengthened by increasing surveillance activities for instance in duck yards. Last, we discuss the dynamics of the duck value chain and further implications for future HPAI management policies. © 2017 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.

  17. Surface layer temperature inversion in the Arabian Sea during winter

    Digital Repository Service at National Institute of Oceanography (India)

    Pankajakshan, T.; Ghosh, A.K.

    picture of the actual inversion phenomena occurring in this area. Figure 1 illustrates the procedure adopted in finding the inversion stations. If the temperature difference (Del T) obtained from (T U –T L ) is greater than 0.2°C, then the station... is more or less consistent. Figure 3-A shows the frequency distribution of temperature difference of the inversion layer (Del T). Figure 3-B shows the frequency distribution of the thickness of the inversion layers in meters (Di). Del T is distributed over...

  18. Some physical characteristics of Andaman sea waters during winter

    Digital Repository Service at National Institute of Oceanography (India)

    RamaRaju, D.V.; Gouveia, A.D.; Murty, C.S.

    Based on the data collected during the cruises of R V Gaveshani in Jan-Feb of 1979 and 1980 around the Andaman Islands, 6 transects are selected, along which the present study on some physical properties of the waters derived from the distributions...

  19. Growth Performance of Pekin Ducks Fed with Golden Snail and Fresh Banana Peelings

    Directory of Open Access Journals (Sweden)

    Ulep, LJL.

    1995-01-01

    Full Text Available The growth performance and economics of feeding confined Pekin ducks with three different levels of golden snail fresh meat and banana peelings in equal percentage for replacing 50 %, 70 % or 90 % of the commercial feed of the diet was studied. Body weight gains and feed consumption of ducks, cost of feed and profit above feed and stock cost different significantly among treatments. Feed conversion varied during the first month of feeding but became comparable after the second month. Ducks fed the diet with 45 % banana peel and 45 % golden snail meat gave the best performance, were the most economical and yielded the highest profit. Snail meat and banana peeling utilization as replacement to commercial diet for ducks is advantageaous in terms of growth performance and cost benefit.

  20. Inheritance patterns of enzymes and serum proteins of mallard-black duck hybrids

    Science.gov (United States)

    Morgan, R.P.; Meritt, D.W.; Block, S.B.; Cole, M.A.; Sulkin, S.T.; Lee, F.B.; Henny, C.J.

    1984-01-01

    From 1974 to 1976, a breeding program was used to produce hybrids of black ducks and mallards for the evaluation of inheritance patterns of serum proteins and serum, liver and muscle enzymes. In addition to the crosses designed to produce hybrids, a series of matings in 1975 and 1976 were designed to evaluate inheritance patterns of a hybrid with either a black duck or mallard. At the F1 level, hybrids were easily distinguished using serum proteins. However, once a hybrid was crossed back to either a mallard or black duck, only 12?23% of the progeny were distinguishable from black ducks or mallards using serum proteins and 23?39% using esterases. Muscle, serum and liver enzymes were similar between the two species.

  1. Harlequin duck capture and EROD activity data from Prince William Sound, Alaska, 2011, 2013, 2014

    Data.gov (United States)

    Department of the Interior — This data set includes capture information and ethoxyresorufin­O­deethylase (EROD) activity results for harlequin ducks sampled during March 2011, 2013, and 2014 in...

  2. Physicochemical properties of meat of ducks of mulberries in modern technologies of meat products

    Directory of Open Access Journals (Sweden)

    R. F. Galin

    2017-01-01

    Full Text Available The article presents the results of studying the chemical composition of mullards duck meat in comparison with the ducks of the Beijingg white breed and musk ducks. The chemical analysis results allow us to note the high moisture content for mullard duck meat. The low fat content for white and red mullard duck meat opens up wide opportunities for the development of an assortment of meat products with a functional orientation. The limited amino acids are determined. The total number of essential amino acids in the mullard duck meat is higher than in musk (by 1.02 g / 100 g protein and Beijingg (by 0.86 g / 100 g protein, which indicates a higher biological value. The limiting amino acid is methionine and cysteine. The article presents the results of the raw material aroma assessment using the "MAG 8" - "electronic nose" analyzer. The content of easily volatile compounds in the equilibrium gas phase for samples of muscle and fat tissue from ducks of different breeding was compared and evaluated. The most informative in the matrix are sensors with films of polydiethylene glycol succinate, polyvinylpyrrolidone, polyethylene glycol PEG-2000, 18-crown-6, trioctylphosphine oxidase, which show maximum sensitivity to polar and nitrogen-containing compounds, aromatic hydrocarbons. This is explained by the fact that the easily volatile fraction of both meat and fat of the samples under study is represented by a variety of organic compounds of different concentrations. Such a variety of substances can be perceived by tasters as "a noticeable smell, difficult". In accordance with the results obtained, we concluded that the aroma of muscle and fat tissue of mulard ducks is more intense, more saturated than the Beijingg duck. The obtained data on the chemical composition indicate possible dietary properties of meat of ducks of mullards. The rich, pronounced aroma of muscle and fatty tissue causes high organoleptic parameters of the finished product, which is

  3. Campylobacter jejuni colonization and population structure in urban populations of ducks and starlings in New Zealand.

    Science.gov (United States)

    Mohan, Vathsala; Stevenson, Mark; Marshall, Jonathan; Fearnhead, Paul; Holland, Barbara R; Hotter, Grant; French, Nigel P

    2013-08-01

    A repeated cross-sectional study was conducted to determine the prevalence of Campylobacter spp. and the population structure of C. jejuni in European starlings and ducks cohabiting multiple public access sites in an urban area of New Zealand. The country's geographical isolation and relatively recent history of introduction of wild bird species, including the European starling and mallard duck, create an ideal setting to explore the impact of geographical separation on the population biology of C. jejuni, as well as potential public health implications. A total of 716 starling and 720 duck fecal samples were collected and screened for C. jejuni over a 12 month period. This study combined molecular genotyping, population genetics and epidemiological modeling and revealed: (i) higher Campylobacter spp. isolation in starlings (46%) compared with ducks (30%), but similar isolation of C. jejuni in ducks (23%) and starlings (21%), (ii) significant associations between the isolation of Campylobacter spp. and host species, sampling location and time of year using logistic regression, (iii) evidence of population differentiation, as indicated by FST , and host-genotype association with clonal complexes CC ST-177 and CC ST-682 associated with starlings, and clonal complexes CC ST-1034, CC ST-692, and CC ST-1332 associated with ducks, and (iv) greater genetic diversity and genotype richness in ducks compared with starlings. These findings provide evidence that host-associated genotypes, such as the starling-associated ST-177 and ST-682, represent lineages that were introduced with the host species in the 19th century. The isolation of sequence types associated with human disease in New Zealand indicate that wild ducks and starlings need to be considered as a potential public health risk, particularly in urban areas. © 2013 The Authors. Microbiology Open published by John Wiley & Sons Ltd.

  4. Study of formation of green eggshell color in ducks through global gene expression.

    Science.gov (United States)

    Xu, Fa Qiong; Li, Ang; Lan, Jing Jing; Wang, Yue Ming; Yan, Mei Jiao; Lian, Sen Yang; Wu, Xu

    2018-01-01

    The green eggshell color produced by ducks is a threshold trait that can be influenced by various factors, such as hereditary, environment and nutrition. The aim of this study was to investigate the genetic regulation of the formation of eggs with green shells in Youxian ducks. We performed integrative analysis of mRNAs and miRNAs expression profiling in the shell gland samples from ducks by RNA-Seq. We found 124 differentially expressed genes that were associated with various pathways, such as the ATP-binding cassette (ABC) transporter and solute carrier supper family pathways. A total of 31 differentially expressed miRNAs were found between ducks laying green eggs and white eggs. KEGG pathway analysis of the predicted miRNA target genes also indicated the functional characteristics of these miRNAs; they were involved in the ABC transporter pathway and the solute carrier (SLC) supper family. Analysis with qRT-PCR was applied to validate the results of global gene expression, which showed a correlation between results obtained by RNA-seq and RT-qPCR. Moreover, a miRNA-mRNA interaction network was established using correlation analysis of differentially expressed mRNA and miRNA. Compared to ducks that lay white eggs, ducks that lay green eggs include six up-regulated miRNAs that had regulatory effects on 35 down-regulated genes, and seven down-regulated miRNAs which influenced 46 up-regulated genes. For example, the ABC transporter pathway could be regulated by expressing gga-miR-144-3p (up-regulated) with ABCG2 (up-regulated) and other miRNAs and genes. This study provides valuable information about mRNA and miRNA regulation in duck shell gland tissues, and provides foundational information for further study on the eggshell color formation and marker-assisted selection for Youxian duck breeding.

  5. Accumulation and elimination of polychlorinated dibenzo-p-dioxins and dibenzofurans in mule ducks.

    Science.gov (United States)

    Wu, Ting-Wei; Lee, Jai-Wei; Liu, Hsueh-Yen; Lin, Wei-Hsiao; Chu, Chun-Yen; Lin, Sheng-Lun; Chang-Chien, Guo Ping; Yu, Chi

    2014-11-01

    In Taiwan, a food safety crisis involving a presence of high concentrations of dioxin residues in duck eggs occurred in 2004. The dioxin content in duck meat sampled from supermarkets was also reported to be substantially higher than in products from other farm animals. Despite increased awareness of the potential for contamination and exposure to dioxins, the accumulation and elimination of dioxins in ducks have not been well characterized. In the present study, mule ducks were fed capsules containing polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) for 14 days and the trial was continued for another 28 days without PCDD/Fs supplementation. Ducks were sacrificed on the 14th, 28th, and 42nd days from the beginning of administration and samples of abdominal fat, breast, and liver tissue were obtained. The concentrations of PCDD/Fs were analyzed in the samples to investigate their distribution and elimination in various duck tissues. The bioaccumulation of PCDD/Fs in ducks was found to be tissue-dependent. In the abdominal fat, the bioconcentration factor was negatively correlated with the degree of chlorination. Conversely, more chlorinated PCDD/Fs (hexa- or hepta-congeners) were associated with higher bioconcentration in the liver and breast tissue. In terms of the efficiency of PCDD/Fs elimination, the liver was found to be the fastest, followed by the breast and the abdominal fat. The clearance rate positively correlated with the degree of chlorination, as determined by comparing the apparent elimination rate constant (k) of PCDD/Fs in various tissues. Overall, lower k values observed in this study imply that mule ducks have a reduced clearance of PCDD/Fs in comparison with layer and broiler chickens. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Study of formation of green eggshell color in ducks through global gene expression.

    Directory of Open Access Journals (Sweden)

    Fa Qiong Xu

    Full Text Available The green eggshell color produced by ducks is a threshold trait that can be influenced by various factors, such as hereditary, environment and nutrition. The aim of this study was to investigate the genetic regulation of the formation of eggs with green shells in Youxian ducks. We performed integrative analysis of mRNAs and miRNAs expression profiling in the shell gland samples from ducks by RNA-Seq. We found 124 differentially expressed genes that were associated with various pathways, such as the ATP-binding cassette (ABC transporter and solute carrier supper family pathways. A total of 31 differentially expressed miRNAs were found between ducks laying green eggs and white eggs. KEGG pathway analysis of the predicted miRNA target genes also indicated the functional characteristics of these miRNAs; they were involved in the ABC transporter pathway and the solute carrier (SLC supper family. Analysis with qRT-PCR was applied to validate the results of global gene expression, which showed a correlation between results obtained by RNA-seq and RT-qPCR. Moreover, a miRNA-mRNA interaction network was established using correlation analysis of differentially expressed mRNA and miRNA. Compared to ducks that lay white eggs, ducks that lay green eggs include six up-regulated miRNAs that had regulatory effects on 35 down-regulated genes, and seven down-regulated miRNAs which influenced 46 up-regulated genes. For example, the ABC transporter pathway could be regulated by expressing gga-miR-144-3p (up-regulated with ABCG2 (up-regulated and other miRNAs and genes. This study provides valuable information about mRNA and miRNA regulation in duck shell gland tissues, and provides foundational information for further study on the eggshell color formation and marker-assisted selection for Youxian duck breeding.

  7. Learning through a Winter's Tale

    Science.gov (United States)

    Vidotto, Kristie

    2010-01-01

    In this article, the author shares her experience during the final semester of Year 11 Theatre Studies when she performed a monologue about Hermione from "The Winter's Tale". This experience was extremely significant to her because it nearly made her lose faith in one of the most important parts of her life, drama. She believes this…

  8. South China Sea

    Science.gov (United States)

    Morton, Brian; Blackmore, Graham

    2001-01-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of the three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the South

  9. South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Morton, Brian [Hong Kong Univ., Swire Inst. of Marine Science, Hong Kong (China); Hong Kong Univ., Dept. of Ecology and Biodiversity, Hong Kong (China); Blackmore, Graham [Hong Kong Univ. of Science and Technology, Dept. of Biology, Hong Kong (China)

    2001-07-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshops and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km{sup 2} and depths range from the shallowest coastal fringe to 5377m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economics on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken

  10. Methylmercury: Second generation reproductive and behavioral effects of mallard ducks

    Science.gov (United States)

    Heinz, G.H.

    1976-01-01

    Mallard ducks (Anas platyrhynchos) whose parents were fed a diet containing 0.5 ppm mercury (equal to about 0.1 ppm mercury in a natural diet) also were fed a diet containing 0.5 ppm mercury beginning at 9 days of age and continuing through their reproductive season. Mercury in the eggs of treated hens averaged 0.86 ppm. Hens fed 0.5 ppm mercury made less efficient use of feed and laid a greater percentage of eggs outside nestboxes compared with controls. Hens fed mercury also produced fewer 1-week-old ducklings than did controls. There were no significant differences between controls and ducklings from parents fed 0.5 ppm mercury in approach responses to tape-recorded maternal calls, in avoidance of a frightening stimulus, or in open-field behavior. Ducklings from parents fed 0.5 pprn mercury did not grow as fast as did control ducklings.

  11. [Book review] Ducks, geese and swans of North America

    Science.gov (United States)

    Krapu, Gary L.

    1983-01-01

    This is the 3rd edition of the classic work "The Ducks, Geese and Swans of North America," which was first published in December 1942.  The original edition was authored by Francis C. Kortright with color plates by T. M. Shortt. An authoritative reference on North American waterfowl for many years, the book had become outdated as a result of major advances in the field of waterfowl biology. The need to update the 1st edition culminated in the publication in 1976 of a 2nd edition authored by Frank Bellrose. Readers interested in comparing features of the 1976 edition with other major recent works on North American waterfowl by P. A. Johnsgard and R. S. Palmer should read Weller (1977, Auk 94: 173).

  12. Linkages between Icelandic Low position and SE Greenland winter precipitation

    Science.gov (United States)

    Berdahl, M.; Rennermalm, A. K.; Hammann, A. C.; Mioduszewski, J.; Hameed, S.; Tedesco, M.; Stroeve, J. C.; Mote, T. L.

    2015-12-01

    Greenland's largest flux of precipitation occurs in its Southeast (SE) region. An understanding of the mechanisms controlling precipitation in this region is lacking despite its disproportionate importance in the mass balance of Greenland and the consequent contributions to sea level rise. We use weather station data from the Danish Meteorological Institute to reveal the governing influences on precipitation in SE Greenland during the winter and fall. We find that precipitation in the fall is significantly correlated to the longitude of the Icelandic Low and the NAO. Winter precipitation is correlated with the strength and longitude of the Icelandic Low, as well as the NAO. We show that in years of extreme high precipitation, onshore winds dominate, thereby advecting more moisture inland. In low precipitation years, winds are more westerly, approaching the stations from land. Understanding the controls of SE Greenland precipitation will help us predict how future precipitation in this key region may change in a warming climate.

  13. Changes in the seasonality of Arctic sea ice and temperature

    Science.gov (United States)

    Bintanja, R.

    2012-04-01

    Observations show that the Arctic sea ice cover is currently declining as a result of climate warming. According to climate models, this retreat will continue and possibly accelerate in the near-future. However, the magnitude of this decline is not the same throughout the year. With temperatures near or above the freezing point, summertime Arctic sea ice will quickly diminish. However, at temperatures well below freezing, the sea ice cover during winter will exhibit a much weaker decline. In the future, the sea ice seasonal cycle will be no ice in summer, and thin one-year ice in winter. Hence, the seasonal cycle in sea ice cover will increase with ongoing climate warming. This in itself leads to an increased summer-winter contrast in surface air temperature, because changes in sea ice have a dominant influence on Arctic temperature and its seasonality. Currently, the annual amplitude in air temperature is decreasing, however, because winters warm faster than summer. With ongoing summer sea ice reductions there will come a time when the annual temperature amplitude will increase again because of the large seasonal changes in sea ice. This suggests that changes in the seasonal cycle in Arctic sea ice and temperature are closely, and intricately, connected. Future changes in Arctic seasonality (will) have an profound effect on flora, fauna, humans and economic activities.

  14. Factors governing the deep ventilation of the Red Sea

    KAUST Repository

    Papadopoulos, Vassilis P.

    2015-11-19

    A variety of data based on hydrographic measurements, satellite observations, reanalysis databases, and meteorological observations are used to explore the interannual variability and factors governing the deep water formation in the northern Red Sea. Historical and recent hydrographic data consistently indicate that the ventilation of the near-bottom layer in the Red Sea is a robust feature of the thermohaline circulation. Dense water capable to reach the bottom layers of the Red Sea can be regularly produced mostly inside the Gulfs of Aqaba and Suez. Occasionally, during colder than usual winters, deep water formation may also take place over coastal areas in the northernmost end of the open Red Sea just outside the Gulfs of Aqaba and Suez. However, the origin as well as the amount of deep waters exhibit considerable interannual variability depending not only on atmospheric forcing but also on the water circulation over the northern Red Sea. Analysis of several recent winters shows that the strength of the cyclonic gyre prevailing in the northernmost part of the basin can effectively influence the sea surface temperature (SST) and intensify or moderate the winter surface cooling. Upwelling associated with periods of persistent gyre circulation lowers the SST over the northernmost part of the Red Sea and can produce colder than normal winter SST even without extreme heat loss by the sea surface. In addition, the occasional persistence of the cyclonic gyre feeds the surface layers of the northern Red Sea with nutrients, considerably increasing the phytoplankton biomass.

  15. Modelling the distribution of chickens, ducks, and geese in China

    Science.gov (United States)

    Prosser, Diann J.; Wu, Junxi; Ellis, Erie C.; Gale, Fred; Van Boeckel, Thomas P.; Wint, William; Robinson, Tim; Xiao, Xiangming; Gilbert, Marius

    2011-01-01

    Global concerns over the emergence of zoonotic pandemics emphasize the need for high-resolution population distribution mapping and spatial modelling. Ongoing efforts to model disease risk in China have been hindered by a lack of available species level distribution maps for poultry. The goal of this study was to develop 1 km resolution population density models for China's chickens, ducks, and geese. We used an information theoretic approach to predict poultry densities based on statistical relationships between poultry census data and high-resolution agro-ecological predictor variables. Model predictions were validated by comparing goodness of fit measures (root mean square error and correlation coefficient) for observed and predicted values for 1/4 of the sample data which were not used for model training. Final output included mean and coefficient of variation maps for each species. We tested the quality of models produced using three predictor datasets and 4 regional stratification methods. For predictor variables, a combination of traditional predictors for livestock mapping and land use predictors produced the best goodness of fit scores. Comparison of regional stratifications indicated that for chickens and ducks, a stratification based on livestock production systems produced the best results; for geese, an agro-ecological stratification produced best results. However, for all species, each method of regional stratification produced significantly better goodness of fit scores than the global model. Here we provide descriptive methods, analytical comparisons, and model output for China's first high resolution, species level poultry distribution maps. Output will be made available to the scientific and public community for use in a wide range of applications from epidemiological studies to livestock policy and management initiatives.

  16. Differential effects of coyotes and red foxes on duck nest success

    Science.gov (United States)

    Sovada, Marsha A.; Sargeant, A.; Grier, J.W.

    1995-01-01

    Low recruitment rates prevail among ducks in the Prairie Pothole Region of North America, primarily because of high nest depredation rates. The red fox (Vulpes vulpes) is a major predator of duck eggs, but fox abundance is depressed by coyotes (Canis latrans). We tested the hypothesis that nest success of upland-nesting ducks is higher in areas with coyotes than in areas with red foxes. We conducted the study during 1990-92 in uplands of 36 areas managed for nesting ducks in North Dakota and South Dakota. Overall nest success averaged 32% (95% CI = 25-40) on 17 study areas where coyotes were the principal canid and 17% (CI = 11-25) on 13 study areas where red foxes were the principal canid (P = 0.01). Both canids were common on 6 other areas, where nest success averaged 25% (CI = 13-47). Habitat composition, predator communities with the exception of canids, and species composition of duck nests in coyote and red fox areas were similar overall. Upon examining only nests with greater than or equal to 6 eggs on the last visit prior to hatch or depredation, we determined nests with evidence characteristic of fox predation accounted for 4% of depredated nests in coyote areas and 27% in fox areas (P = 0.001). An expanding coyote population is contributing to higher overall nest success. Management of coyotes may be an effective method for increasing duck nest success.

  17. Effects of dietary gossypol concentration on growth performance, blood profiles, and hepatic histopathology in meat ducks.

    Science.gov (United States)

    Zeng, Q F; Yang, G L; Liu, G N; Wang, J P; Bai, S P; Ding, X M; Luo, Y H; Zhang, K Y

    2014-08-01

    The objective of this study was to determine the effects of gossypol from cottonseed meal (CSM) on growth performance, blood biochemical profiles, and liver histopathology of ducks. A total of 900 1-d-old ducks were randomly allocated to 5 treatments with 12 pens/treatment and 15 ducks/pen. The 5 experimental diets were formulated in such a way that 0% (a corn-soybean meal basal diet, diet 1), 25% (diet 2), 50% (diet 3), 75% (diet 4), and 100% (diet 5) of protein from soybean meal were replaced with that from CSM. All diets were formulated on a digestible amino acid basis. The experiment included 2 phases, the starter phase (1 to 3 wk) where the test diets contained graded levels of CSM and the growth phase (4 to 5 wk) where birds were fed a corn-soybean basal diet to examine the recovery of ducks after CSM withdrawal. Dietary CSM and gossypol linearly (P ducks among all treatments. These results suggest that meat ducks' dietary TG and FG concentration should be lower than 928.9 and 77.2 mg/kg, respectively, during d 1 to 21 of age and that a 2-wk withdrawal of diets containing gossypol should be considered. © Poultry Science Association Inc.

  18. Comparative amino acid digestibility for broiler chickens and White Pekin ducks.

    Science.gov (United States)

    Kong, C; Adeola, O

    2013-09-01

    A total of 608 three-week-old male broiler chickens and White Pekin ducks were used in a 5-d trial to compare ileal amino acid (AA) digestibility of soybean meal (SBM) and canola meal (CM) using the regression method. A corn-casein-cornstarch-based diet was mixed to contain 15% CP. Cornstarch was replaced with test ingredient (SBM or CM) to contain 18 or 21% of CP in 4 other diets. A nitrogen-free diet (NFD) was used for standardization of apparent digestibility. Birds received a standard starter diet (23% CP) from d 0 to 14 posthatch and then 6 experimental diets for 5 d. On d 19 posthatch, birds were asphyxiated with CO(2), and digesta from the distal section of ileum was collected. The ileal digestibility of AA from the test ingredients was assessed by multiple linear regression analysis using data on daily apparent ileal digestible AA and total AA intakes. The basal endogenous losses of N and all AA for ducks were significantly higher than those for broilers. For ileal AA digestibility by regression of apparent digestible AA intake against AA intake, there was a higher (P ducks compared with broilers (P ducks, and Lys and Pro of broilers (P study showed that ducks have higher basal endogenous AA losses compared with broiler chickens as well as higher ileal Cys and Pro digestibility estimates derived from regression approach, indicating that data obtained from broilers should not be used to formulate diets for ducks.

  19. Inhibition of duck hepatitis B virus replication by mimic peptides in vitro.

    Science.gov (United States)

    Jia, Hongyu; Liu, Changhong; Yang, Ying; Zhu, Haihong; Chen, Feng; Liu, Jihong; Zhou, Linfu

    2015-11-01

    The aim of the present study was to investigate the inhibitory effect of specific mimic peptides targeting duck hepatitis B virus polymerase (DHBVP) on duck hepatitis B virus (DHBV) replication in primary duck hepatocytes. Phage display technology (PDT) was used to screen for mimic peptides specifically targeting DHBVP and the associated coding sequences were determined using DNA sequencing. The selected mimic peptides were then used to treat primary duck hepatocytes infected with DHBV in vitro. Infected hepatocytes expressing the mimic peptides intracellularly were also prepared. The cells were divided into mimic peptide groups (EXP groups), an entecavir-treated group (positive control) and a negative control group. The medium was changed every 48 h. Following a 10-day incubation, the cell supernatants were collected. DHBV-DNA in the cellular nucleus, cytoplasm and culture supernatant was analyzed by quantitative polymerase chain reaction (qPCR). Eight mimic peptides were selected following three PDT screening rounds for investigation in the DHBV-infected primary duck hepatocytes. The qPCR results showed that following direct treatment with mimic peptide 2 or 7, intracellular expression of mimic peptide 2 or 7, or treatment with entecavir, the DHBV-DNA levels in the culture supernatant and cytoplasm of duck hepatocytes were significantly lower than those in the negative control (Pmimic peptide 7 was lower than that in the other groups (Pmimic peptide 7 was significantly lower than that in the other groups (PMimic peptides specifically targeting DHBVP, administered directly or expressed intracellularly, can significantly inhibit DHBV replication in vitro .

  20. The diet of the South American sea lion (Otaria flavescens at Río Negro, Patagonia, Argentina, during the winter-spring period Dieta del lobo marino de un pelo sudamericano (Otaria flavescens en Río Negro, Patagonia, Argentina, durante el invierno y primavera

    Directory of Open Access Journals (Sweden)

    Raimundo L. Bustos

    2012-12-01

    Full Text Available The South American sea lion, Otaria flavescens (Shaw, 1800 population is steadily expanding along the Patagonian coast of Argentina in the last decades. However, little is known about the feeding ecology of the species in the area. The aim of this study was to analyze the food habits of O. flavescens from 91 scats collected at Río Negro province, during the winter and spring of 2005. Fish occurred in 96% of scats containing prey remains, followed by cephalopods (26%. Raneya brasiliensis (Kaup, 1856 was the most frequent and abundant species occurring in 58.6% of samples and constituting almost 50% of fish predated. Second in importance were Porichthys porosissimus (Cuvier, 1829 and Cynoscion guatucupa (Cuvier, 1830 in terms of occurrence (%FO 20.7 and numbers (29.6% respectively. The squid Loligo gahi (d'Orbigny, 1835 was the most frequent cephalopod prey (42.1%, whereas Octopus tehuelchus (d'Orbigny, 1834 was the most abundant (77%. The higher amount and diversity of prey found in the spring in comparison with the winter season might be related to a higher feeding activity of seals or to a seasonal increase in food availability in the area.La población del lobo marino de un pelo sudamericano Otaria flavescens (Shaw, 1800 ha experimentado un crecimiento continuo en las ultimas décadas en las costas de la Patagonia Argentina. Sin embargo, poco se conoce sobre la ecología trófica de la especie en el área. El objetivo de este estudio fue analizar los hábitos alimentarios de O. flavescens a partir de 91 fecas colectadas en la provincia de Río Negro, durante el invierno y la primavera del 2005. Los peces estuvieron presentes en el 96% de las fecas que contenían remanentes presas, seguidos por los cefalópodos (26%. Raneya brasiliensis (Kaup, 1856 fue la especie mas frecuente y abundante ocurriendo en el 58.6% de las muestras y constituyendo casi el 50% de los peces predados. Le siguieron en importancia Porichthys porosissimus (Cuvier, 1829 y

  1. Transcriptome analysis of duck liver and identification of differentially expressed transcripts in response to duck hepatitis A virus genotype C infection.

    Science.gov (United States)

    Tang, Cheng; Lan, Daoliang; Zhang, Huanrong; Ma, Jing; Yue, Hua

    2013-01-01

    Duck is an economically important poultry and animal model for human viral hepatitis B. However, the molecular mechanisms underlying host-virus interaction remain unclear because of limited information on the duck genome. This study aims to characterize the duck normal liver transcriptome and to identify the differentially expressed transcripts at 24 h after duck hepatitis A virus genotype C (DHAV-C) infection using Illumina-Solexa sequencing. After removal of low-quality sequences and assembly, a total of 52,757 unigenes was obtained from the normal liver group. Further blast analysis showed that 18,918 unigenes successfully matched the known genes in the database. GO analysis revealed that 25,116 unigenes took part in 61 categories of biological processes, cellular components, and molecular functions. Among the 25 clusters of orthologous group categories (COG), the cluster for "General function prediction only" represented the largest group, followed by "Transcription" and "Replication, recombination, and repair." KEGG analysis showed that 17,628 unigenes were involved in 301 pathways. Through comparison of normal and infected transcriptome data, we identified 20 significantly differentially expressed unigenes, which were further confirmed by real-time polymerase chain reaction. Of the 20 unigenes, nine matched the known genes in the database, including three up-regulated genes (virus replicase polyprotein, LRRC3B, and PCK1) and six down-regulated genes (CRP, AICL-like 2, L1CAM, CYB26A1, CHAC1, and ADAM32). The remaining 11 novel unigenes that did not match any known genes in the database may provide a basis for the discovery of new transcripts associated with infection. This study provided a gene expression pattern for normal duck liver and for the previously unrecognized changes in gene transcription that are altered during DHAV-C infection. Our data revealed useful information for future studies on the duck genome and provided new insights into the molecular

  2. The Importance of Non-Native Prey, the Zebra Mussel Dreissena polymorpha, for the Declining Greater Scaup Aythya marila: A Case Study at a Key European Staging and Wintering Site.

    Directory of Open Access Journals (Sweden)

    Dominik Marchowski

    Full Text Available The European population of Greater Scaup Aythya marila has experienced an alarming, ~60% decline in numbers over the last two decades. The brackish lagoons of the Odra River Estuary (ORE in the south-western Baltic Sea, represent an important area for the species during the non-breeding season in Europe. The lagoons regularly support over 20 000 Scaup, with peaks exceeding 100 000 (38%-70% of the population wintering in NW Europe and the highest number recorded in April 2011-105 700. In the ORE, Scaup feed almost exclusively on the non-native Zebra Mussel Dreissena polymorpha. This mussel was present in the ORE already in the 19th century and continues to be superabundant. Using the results of 22 Scaup censuses (November to April 2002/2003 to 2013/2014 from the whole ORE (523 km2 of water, we show that Scaup flocks follow areas with the greatest area of occurrence and biomass of the Zebra Mussel, while areas with low mussel densities are ignored. The numbers of Scaup in the ORE are primarily related to the area of Zebra Mussel occurrence on the lagoon's bottom (km2 in a non-linear fashion. Zebra Mussels were absolutely prevalent (97% of biomass in the digestive tracts of birds unintentionally by-caught in fishing nets (n = 32. We estimate that Scaup alone consume an average of 5 400 tons of Zebra Mussels annually, which represents 5.6% of the total resources of the mussel in the ORE. Our results provide a clear picture of the strong dependence of the declining, migratory duck species on the non-native mussel, its primary food in the ORE. Our findings are particularly important as they can form the basis for the conservation action plan aimed at saving the north-western European populations of Scaup.

  3. The Importance of Non-Native Prey, the Zebra Mussel Dreissena polymorpha, for the Declining Greater Scaup Aythya marila: A Case Study at a Key European Staging and Wintering Site.

    Science.gov (United States)

    Marchowski, Dominik; Neubauer, Grzegorz; Ławicki, Łukasz; Woźniczka, Adam; Wysocki, Dariusz; Guentzel, Sebastian; Jarzemski, Maciej

    2015-01-01

    The European population of Greater Scaup Aythya marila has experienced an alarming, ~60% decline in numbers over the last two decades. The brackish lagoons of the Odra River Estuary (ORE) in the south-western Baltic Sea, represent an important area for the species during the non-breeding season in Europe. The lagoons regularly support over 20 000 Scaup, with peaks exceeding 100 000 (38%-70% of the population wintering in NW Europe and the highest number recorded in April 2011-105 700). In the ORE, Scaup feed almost exclusively on the non-native Zebra Mussel Dreissena polymorpha. This mussel was present in the ORE already in the 19th century and continues to be superabundant. Using the results of 22 Scaup censuses (November to April 2002/2003 to 2013/2014) from the whole ORE (523 km2 of water), we show that Scaup flocks follow areas with the greatest area of occurrence and biomass of the Zebra Mussel, while areas with low mussel densities are ignored. The numbers of Scaup in the ORE are primarily related to the area of Zebra Mussel occurrence on the lagoon's bottom (km2) in a non-linear fashion. Zebra Mussels were absolutely prevalent (97% of biomass) in the digestive tracts of birds unintentionally by-caught in fishing nets (n = 32). We estimate that Scaup alone consume an average of 5 400 tons of Zebra Mussels annually, which represents 5.6% of the total resources of the mussel in the ORE. Our results provide a clear picture of the strong dependence of the declining, migratory duck species on the non-native mussel, its primary food in the ORE. Our findings are particularly important as they can form the basis for the conservation action plan aimed at saving the north-western European populations of Scaup.

  4. Impacts of Climate Modes on Air–Sea Heat Exchange in the Red Sea

    KAUST Repository

    Abualnaja, Yasser

    2015-04-01

    The impacts of various climate modes on the Red Sea surface heat exchange are investigated using the MERRA reanalysis and the OAFlux satellite reanalysis datasets. Seasonality in the atmospheric forcing is also explored. Mode impacts peak during boreal winter [December–February (DJF)] with average anomalies of 12–18 W m−2 to be found in the northern Red Sea. The North Atlantic Oscillation (NAO), the east Atlantic–west Russia (EAWR) pattern, and the Indian monsoon index (IMI) exhibit the strongest influence on the air–sea heat exchange during the winter. In this season, the largest negative anomalies of about −30 W m−2 are associated with the EAWR pattern over the central part of the Red Sea. In other seasons, mode-related anomalies are considerably lower, especially during spring when the mode impacts are negligible. The mode impacts are strongest over the northern half of the Red Sea during winter and autumn. In summer, the southern half of the basin is strongly influenced by the multivariate ENSO index (MEI). The winter mode–related anomalies are determined mostly by the latent heat flux component, while in summer the shortwave flux is also important. The influence of the modes on the Red Sea is found to be generally weaker than on the neighboring Mediterranean basin.

  5. Impact of curcumin supplementation in monochromatic light on lipid serum profile of sexually mature female Magelang ducks

    Directory of Open Access Journals (Sweden)

    K. Kasiyati

    2018-03-01

    Full Text Available An experiment was conducted to study the effect of curcumin supplementation inexpose monochromatic light on serum lipid concentrations of sexually mature female magelang duck. One hundred and ninety two female magelang ducks were assigned into a completely randomized design with a 4×4 factorial arrangement and each experimental unit was repeated 3 times, each with 4 female magelang ducks. The first factor was dose of curcumin supplementation consisted of 4 levels i.e., 0, 9, 18, and 36 mg/duck/day. The second factor was the color of monochromatic light consisted of 4 levels i.e., white, red, green, and blue colors. The data were analyzed by two-way ANOVA. The result showed that serum concentrations of triglyceride, cholesterol, very low density lipoprotein (VLDL, and low density lipoprotein (LDL were lower (P<0.05 while high density lipoprotein (HDL were higher (P<0.05 in experimental ducks supplemented with a curcumin dose of 36 mg/duck/day in variety of monochromatic light colors compared to control experimental ducks without curcumin supplementation. The curcumin doses of 18 or 36 mg/duck/day within red, green, or blue light had the potential to modulate lipid metabolism, as indicated by the increased serum concentration of HDL and the decreased serum concentrations of triglyceride, cholesterol, VLDL, and LDL of the experimental female magelang ducks.

  6. Examination of Growth Hormone (GH) Gene Polymorphism and its Association with Body Weight and Selected Body Dimensions in Ducks.

    Science.gov (United States)

    Mazurowski, Artur; Frieske, Anna; Kokoszynski, Dariusz; Mroczkowski, Sławomir; Bernacki, Zenon; Wilkanowska, Anna

    2015-01-01

    The main objective of the study was to assess the polymorphism in intron 2 of the GH gene and its association with some morphological traits (body weight--BW, length of trunk with neck--LTN, length of trunk--LT, chest girth--CG, length of breast bone--LBB, length of shank--LS). Polymorphism in intron 2 of the GH gene was evaluated for four duck populations (Pekin ducks AF51, Muscovy ducks from a CK and CRAMMLCFF mother and Mulard ducks). Genetic polymorphism was determined with the PCR-RFLP method using the BsmFI restriction enzyme. In the studied duck sample two alleles (GH(C) and GH(T)) and three genotypes (GH/TT, GH/CT, GH/CC) were found at locus GH/BsmFI. In both groups of Muscovies and in Mulards the dominant allele was GH(T). On the contrary in Pekin ducks AF51, the frequency of both alleles was found to be similar. The most frequent genotype in the examined ducks was GH/TT. In Pekin ducks AF51 three genotypes were observed, while in Mulard ducks and in male Muscovy ducks from a mother marked as CK, two genotypes (GH/TT and GH/CT) were identified. Muscovy duck females from a CK mother and all males and females of Muscovy duck from a CRAMMLCFF mother were monomorphic with only the GH/TTgenotype detected. The results showed that males of Pekin duck AF51 with the GH/TT genotype were characterized by higher (P ducks AF51, this same trend was observed; individuals with GH/TT genotype were superior (P ducks with the GH/TT genotype were distinguished by higher values of all evaluated traits compared to ducks with GH/CT and GH/CC genotypes, however most of the recorded differences were not significant. The only trait markedly impacted (P < 0.05) by the polymorphism of the GH gene intron 2 was the LS value in males.

  7. Is ability to hepatic steatosis influenced by age at the beginning of the overfeeding period in Muscovy and Pekin ducks?

    Science.gov (United States)

    Chartrin, P; Bernadet, M D; Sannier, M; Baéza, E

    2013-04-01

    The aim of this study was to analyse the effects of species (Muscovy and Pekin ducks) and age at the beginning of the overfeeding period on fatty liver production, carcass composition and lipid and moisture content of the liver and breast muscle. We reared four groups of 40 ducks per species for the study, starting at 2-week intervals in order to have four different ages together at the beginning of the overfeeding period (10, 12, 14 and 16 weeks). At the end of the overfeeding period, all ducks were slaughtered. Our results confirmed the high levels of difference in carcass composition and lipid content in the plasma, liver and breast muscle between Muscovy and Pekin ducks at all ages. Pekin ducks were not able to develop a high degree of hepatic steatosis, but had increased lipid storage in peripheral adipose and muscle tissues than Muscovy ducks. However, the fatty liver weight of Pekin ducks increased with age, with lipid deposition in the liver and peripheral tissues. The ability of Muscovy ducks to produce fatty livers remained unchanged with age in line, with lipid deposition in the liver and peripheral tissues. The sites of lipid deposition thus depend on species and not on the physiological maturity of ducks.

  8. Risks of avian influenza transmission in areas of intensive free-ranging duck production with wild waterfowl

    Science.gov (United States)

    Cappelle, Julien; Zhao, Delong; Gilbert, Marius; Newman, Scott H.; Takekawa, John Y.; Gaidet, Nicolas; Prosser, Diann J.; Liu, Ying; Li, Peng; Shu, Yuelong; Xiao, Xiangming

    2014-01-01

    For decades, southern China has been considered to be an important source for emerging influenza viruses since key hosts live together in high densities in areas with intensive agriculture. However, the underlying conditions of emergence and spread of avian influenza viruses (AIV) have not been studied in detail, particularly the complex spatiotemporal interplay of viral transmission between wild and domestic ducks, two major actors of AIV epidemiology. In this synthesis, we examine the risks of avian influenza spread in Poyang Lake, an area of intensive free-ranging duck production and large numbers of wild waterfowl. Our synthesis shows that farming of free-grazing domestic ducks is intensive in this area and synchronized with wild duck migration. The presence of juvenile domestic ducks in harvested paddy fields prior to the arrival and departure of migrant ducks in the same fields may amplify the risk of AIV circulation and facilitate the transmission between wild and domestic populations. We provide evidence associating wild ducks migration with the spread of H5N1 in the spring of 2008 from southern China to South Korea, Russia, and Japan, supported by documented wild duck movements and phylogenetic analyses of highly pathogenic avian influenza H5N1 sequences. We suggest that prevention measures based on a modification of agricultural practices may be implemented in these areas to reduce the intensity of AIV transmission between wild and domestic ducks. This would require involving all local stakeholders to discuss feasible and acceptable solutions.

  9. The estimation of genetic distance and discriminant variables on breed of duck (Alabio, Bali, Khaki Campbell, Mojosari and Pegagan by morphological analysis

    Directory of Open Access Journals (Sweden)

    B Brahmantiyo

    2003-03-01

    Full Text Available A study on morphological body conformation of Alabio, Bali, Khaki Campbell, Mojosari and Pegagan ducks was carried out to determine the genetic distance and discriminant variables. This research was held in Research Institute for Animal Production, Ciawi, Bogor using 65 Alabio ducks, 40 Bali ducks, 36 Khaki Campbell ducks, 60 Mojosari ducks and 30 Pegagan ducks. Seven different body parts were measured, they were the length of femur, tibia, tarsometatarsus, the circumference of tarsometatarsus, the length of third digits, wing and maxilla. General Linear Models and simple discriminant analysis were used in this observation (SAS package program. Male and female Pegagan ducks had morphological size bigger than Alabio, Bali, Khaki Campbell and Mojosari ducks. Khaki Campbell ducks were mixed with Bali ducks (47.22% and Pegagan ducks from isolated location in South Sumatera were lightly mixed with Alabio and Bali. Mahalanobis genetic distance showed that Bali and Khaki Campbell ducks, also, Alabio and Mojosari ducks had similarity, with genetic distance of 1.420 and 1.548, respectively. Results from canonical analysis showed that the most discriminant variables were obtained from the length of femur, tibia and third digits.

  10. Winter feeding activity of the common starfish (Asterias rubens L.): The role of temperature and shading

    NARCIS (Netherlands)

    Agüera García, A.; Trommelen, M.A.; Burrows, F.; Jansen, J.M.; Schellekens, T.; Smaal, A.C.

    2012-01-01

    In the Wadden Sea common starfish is an important predator of mussel beds which in turn are relevant ecological and economic resource. To improve the management of mussel seedbeds, knowledge is required on over winter predation, a factor affecting mussel survival. The aim of this study was to assess

  11. A robust empirical seasonal prediction of winter NAO and surface climate.

    Science.gov (United States)

    Wang, L; Ting, M; Kushner, P J

    2017-03-21

    A key determinant of winter weather and climate in Europe and North America is the North Atlantic Oscillation (NAO), the dominant mode of atmospheric variability in the Atlantic domain. Skilful seasonal forecasting of the surface climate in both Europe and North America is reflected largely in how accurately models can predict the NAO. Most dynamical models, however, have limited skill in seasonal forecasts of the winter NAO. A new empirical model is proposed for the seasonal forecast of the winter NAO that exhibits higher skill than current dynamical models. The empirical model provides robust and skilful prediction of the December-January-February (DJF) mean NAO index using a multiple linear regression (MLR) technique with autumn conditions of sea-ice concentration, stratospheric circulation, and sea-surface temperature. The predictability is, for the most part, derived from the relatively long persistence of sea ice in the autumn. The lower stratospheric circulation and sea-surface temperature appear to play more indirect roles through a series of feedbacks among systems driving NAO evolution. This MLR model also provides skilful seasonal outlooks of winter surface temperature and precipitation over many regions of Eurasia and eastern North America.

  12. 36 CFR 1002.19 - Winter activities.

    Science.gov (United States)

    2010-07-01

    ... RECREATION § 1002.19 Winter activities. (a) Skiing, snowshoeing, ice skating, sledding, innertubing, tobogganing and similar winter sports are prohibited on Presidio Trust roads and in parking areas open to...

  13. Classification guide: Sochi 2014 Paralympic Winter Games

    OpenAIRE

    2014-01-01

    The Sochi 2014 Paralympic Winter Games classification guide is designed to provide National Paralympic Committees (NPCs) and International Federations (IFs) with information about the classification policies and procedures that will apply to the Sochi 2014 Paralympic Winter Games.

  14. Essential Outdoor Sun Safety Tips for Winter

    Science.gov (United States)

    ... Weekend Warriors expand/collapse Vitamin D Essential Outdoor Sun Safety Tips for Winter Winter sports enthusiasts are ... skiing! Be Mindful of Time Spent in the Sun, Regardless of the Season If possible, ski early ...

  15. THE DIGESTIBILITY OF NUTRIENTS AT DIFFERENT LEVELS AND SOURCES OF LIPIDS IN DUCK DIETS

    Directory of Open Access Journals (Sweden)

    M.Yu. Sychov

    2016-04-01

    Full Text Available The estimation of digestibility of nutrients in ducklings was performed by use of feed contained the lipids from different levels and sources. Experimental studies were conducted in terms of problem research laboratory of feed additives of National Agriculture University of Ukraine. The material for scientific experiments was the ducklings of cross STAR 53 H.Y. Experiment was carried out by group-analog method. We determined the optimal content of crude fat in fodder of young ducks at the first stage of experiment and the best source of lipids at second stage. We increased the crude fat in duckling feed by the introduction of sunflower oil at first stage. The amount of fat in the duck feed was 5% in control group and this were 3% and 7% in group II and III. The ducks from experimental groups received feed with sunflower oil at the second stage of experiment, the ducks of group II and III obtained feed from soya, rapeseed, and palm fat. Feeding the ducks was done per group twice per day – in morning and evening. It was registered that the feeding of 8-14 days ducks by food with crude fat of 7% plausible increased the digestibility of protein by 3.2%, of fat by 5.1%, and nitrogen-free extractives matters by 2.7%. At the same time the use of feed for 36-42 days ducks with crude fat of 7% allows to get the best results with the more higher level of protein and fat digestibility by 4.9% and 4.8% respectively. The use of feed with the addition of soybean oil for duck feeding have a positive effect towards increasing the level of digestibility of organic matter, protein, fat, and fiber in all the duck age groups. At the same time the use of feed containing palm oil reduces the digestibility of fat by 4,1-6,7%  compared to control group, that obtained feed with sunflower oil . We confirmed the prospect of further research in order to to establish the optimal ratio of saturated and unsaturated fatty acids in the diet of ducks and to determine their

  16. Comparison of East Asian winter monsoon indices

    Directory of Open Access Journals (Sweden)

    Gao Hui

    2007-01-01

    Full Text Available Four East Asian winter monsoon (EAWM indices are compared in this paper. In the research periods, all the indices show similar interannual and decadal-interdecadal variations, with predominant periods centering in 3–4 years, 6.5 years and 9–15 years, respectively. Besides, all the indices show remarkable weakening trends since the 1980s. The correlation coefficient of each two indices is positive with a significance level of 99%. Both the correlation analyses and the composites indicate that in stronger EAWM years, the Siberian high and the higher-level subtropical westerly jet are stronger, and the Aleutian low and the East Asia trough are deeper. This circulation pattern is favorable for much stronger northwesterly wind and lower air temperature in the subtropical regions of East Asia, while it is on the opposite in weaker EAWM years. Besides, EAWM can also exert a remarkable leading effect on the summer monsoon. After stronger (weaker EAWM, less (more summer precipitation is seen over the regions from the Yangtze River valley of China to southern Japan, while more (less from South China Sea to the tropical western Pacific.

  17. 32th Winter Workshop on Nuclear Dynamics

    CERN Document Server

    2016-01-01

    The 32nd edition of the Winter Workshop will be held 28 February - 5 March 2016, Hotel Resort Fort Royal Guadeloupe in Guadeloupe a French overseas territory, is an island group in the southern Caribbean Sea. As with previous years, the workshop will bring together scientists from all fields of nuclear physics for engaging and friendly exchanges of ideas. Much emphasis will be on the recent LHC, RHIC and SPS heavy ion results, but advances in the ongoing and future programs at FAIR, FRIB, EIC, JLab and NICA and will also be featured. The meeting will start with a welcome reception on the evening of Sunday, February 28. The workshop program will commence on Monday morning and run until Saturday. We recommend to arrive on Sunday and leave on Sunday. Talks will be as usual 25+5 minutes, there will be no parallel sessions. If you are interested in presenting your work, please fill out the registration form prior to the registration deadline. After the program committee has met we will confirm your talk via indivi...

  18. Leadership in American Indian Communities: Winter Lessons

    Science.gov (United States)

    Metoyer, Cheryl A.

    2010-01-01

    Winter lessons, or stories told in the winter, were one of the ways in which tribal elders instructed and directed young men and women in the proper ways to assume leadership responsibilities. Winter lessons stressed the appropriate relationship between the leader and the community. The intent was to remember the power and purpose of that…

  19. 46 CFR 45.73 - Winter freeboard.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Winter freeboard. 45.73 Section 45.73 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Freeboards § 45.73 Winter freeboard. The minimum winter freeboard (fw) in inches is obtained by the formula: fw=f(s)+T s...

  20. The effect of changing sea ice on the vulnerability of Arctic coasts

    OpenAIRE

    K. R. Barnhart; I. Overeem; R. S. Anderson

    2014-01-01

    Shorefast sea ice prevents the interaction of the land and the ocean in the Arctic winter and influences this interaction in the summer by governing the fetch. In many parts of the Arctic the sea-ice-free season is increasing in duration, and the summertime sea ice extents are decreasing. Sea ice provides a first order control on the vulnerability of Arctic coasts to erosion, inundation, and damage to settlements and infrastructure. We ask how the changing sea ic...

  1. Link between the Barents Oscillation and recent boreal winter cooling over the Asian midlatitudes

    Science.gov (United States)

    Shu, Qi; Qiao, Fangli; Song, Zhenya; Song, Yajuan

    2018-01-01

    The link between boreal winter cooling over the midlatitudes of Asia and the Barents Oscillation (BO) since the late 1980s is discussed in this study, based on five datasets. Results indicate that there is a large-scale boreal winter cooling during 1990-2015 over the Asian midlatitudes, and that it is a part of the decadal oscillations of long-term surface air temperature (SAT) anomalies. The SAT anomalies over the Asian midlatitudes are significantly correlated with the BO in boreal winter. When the BO is in its positive phase, anomalously high sea level pressure over the Barents region, with a clockwise wind anomaly, causes cold air from the high latitudes to move over the midlatitudes of Asia, resulting in anomalous cold conditions in that region. Therefore, the recent increasing trend of the BO has contributed to recent winter cooling over the Asian midlatitudes.

  2. Composition and sources of winter and summertime aerosols at Ny Alesund, Spitsbergen

    International Nuclear Information System (INIS)

    Maenhaut, W.; Cornille, P.; Pacyna, J.M.

    1991-01-01

    Filter samples of < 2.5 μm aerosol were collected in (late) winter of 1983, 1984, 1986, and 1987 and in the summer of 1984, 1986, and 1987 at Ny Alesund, Spitsbergen, and analyzed for over 40 elements by a combination of INAA and PIXE. The data sets of the various sampling campaigns and the combined winter and combined summer data were examined by receptor modeling, including absolute principal component analysis (APCA), chemical mass balance (CMB) and multiple linear regression (MLR) techniques. APCA yielded four components, both for the winter and for the summer aerosol. For the winter aerosol, the components were identified as a general pollution component, crustal dust, sea-salt, and a halogen (Br,I) component. The CMB and MLR calculations were used to obtain source (source region) apportionments for the anthropogenic trace elements and for sulfate. For the summer, about 50% of the sulfate was attributed to a marine biogenic source

  3. 76 FR 22140 - Parker River and Thacher Island National Wildlife Refuges, Essex County, MA; Comprehensive...

    Science.gov (United States)

    2011-04-20

    ..., particularly migratory birds and wintering American black ducks. A focus of management is to serve as a land... recent sea level rise study predicts that Plum Island's natural and cultural resources are imminently...

  4. Restoration of sea eagle population: A review

    Directory of Open Access Journals (Sweden)

    Josef RAJCHARD

    2009-10-01

    Full Text Available The population density of the white-tailed sea eagle Haliaeetus albicilla is very low in many countries. In last twenty years, the sea eagle population in South Bohemia was restored by strict protection subsidized by reintroduction. The active help consisted of feeding during winter and building of artificial nests. A new sea eagle breeding population arose in the Třeboň basin area in the early 1980’s. Until this time sea eagles had used former breeding places only for wintering, probably coming from the Baltic. The South Bohemian sea eagle population is very unique: it exists in a densely man-occupied landscape, mainly in areas with very intensive carp breeding in artificial fishponds and was partly artficially (help to wintering birds and reintroduction of some individuals restored. The experience from South Bohemia may have importance for populations of the sea eagle in other areas of its occurence, primarily in the continental conditions [Current Zoology 55 (5:–2009].

  5. Antioxidant Enzyme Activity and Meat Quality of Meat Type Ducks Fed with Dried Oregano ( L. Powder

    Directory of Open Access Journals (Sweden)

    J. H. Park

    2015-01-01

    Full Text Available One-day-old Cherry valley meat-strain ducks were used to investigate the effect of supplemental dried oregano powder (DOP in feed on the productivity, antioxidant enzyme activity, and breast meat quality. One hundred sixty five ducks were assigned to 5 dietary treatments for 42 days. The dietary treatment groups were control group (CON; no antibiotic, no DOP, antibiotic group (ANT; CON+0.1% Patrol, 0.1% DOP (CON+0.1% DOP, 0.5% DOP (CON+0.5% DOP, and 1.0% DOP (CON+1.0% DOP. Upon feeding, 1,1-diphenyl-2-picryl-hydrazyl (DPPH radical scavenging activity of oregano extracts was higher than that of tocopherol, although it was less than that of ascorbic acid. As a result of in vivo study, DOP in the diet showed no effects on final body weight, feed intake, or feed conversion ratio. However, dietary 0.5% and 1% DOP supplementation caused a significant increase in the serum enzyme activity of superoxide dismutase (SOD compared with CON and ANT, while glutathione peroxidase (GPx in tissue was increased as compared to ANT (p<0.05. Cooking loss from ducks fed with DOP decreased compared with the control ducks. Thiobarbituric acid reactive substance (TBARS values of duck breast meat at 5 d post slaughter was found to be significantly reduced in ducks whose diets were supplemented with 0.5% and 1% DOP (p<0.05. These results suggest that diets containing 0.5% and 1% DOP may beneficially affect antioxidant enzyme activity of GPx and SOD, improve meat cooking loss, and reduce TBARS values in breast meat at 5 d of storage in ducks.

  6. Influence of indoor microbial aerosol on the welfare of meat ducks.

    Science.gov (United States)

    Yu, G L; Wei, L M; Liu, Y Y; Liu, J Y; Wang, Y; Gao, J; Chai, T J; Cai, Y M

    2016-01-01

    The aim of the study was to evaluate the effects of microbial aerosols on ducks' welfare and provide information on which to establish microbial aerosol concentration standards for poultry. A total of 1800 1-d-old Cherry Valley ducks were randomly divided into 5 groups (A, B, C, D and E) with 360 ducks in each. To obtain objective data, each group had three replications. Different microbial aerosol concentrations in different groups were created by controlling ventilation and bedding cleaning frequency. Group A was the control group and hygienic conditions deteriorated progressively from group B to E. A 6-stage Andersen impactor was used to detect the aerosol concentration of aerobes, fungi, gram-negative bacteria and an AGI-30 microbial air sampler detected endotoxins. Physiological stress was evaluated in the ducks by adrenocorticotropic hormone (ACTH) values in serum. To assess the effects of bioaerosol factors, welfare indicators including fluctuating asymmetry (FA), appearance and gait as well as the Lactobacillus caecal concentration were evaluated. The data showed group D had already reached the highest limit of concentration of airborne aerobic bacteria, airborne fungi, airborne gram-negative bacteria and airborne endotoxin. The ducks in this group had significantly increased serum ACTH values and significantly decreased caecal lactobacilli concentration. Furthermore, appearance and gait scores, wing length and overall FA and caecal Lactobacillus concentration in this group were significantly increased at 6 and 8 weeks of age. In conclusion, high concentrations of microbial aerosol adversely affected the welfare of meat ducks. The microbial aerosol values in group D suggest a preliminary upper limit concentration of bioaerosols in ambient air for healthy meat ducks.

  7. Flow cytometric DNA analysis of ducks accumulating 137Cs on a reactor reservoir

    International Nuclear Information System (INIS)

    George, L.S.; Dallas, C.E.; Brisbin, I.L. Jr.; Evans, D.L.

    1991-01-01

    The objective of this study was to detect red blood cell (rbc) DNA abnormalities in male, game-farm mallard ducks as they ranged freely and accumulated 137Cs (radiocesium) from an abandoned nuclear reactor cooling reservoir. Prior to release, the ducks were tamed to enable recapture at will. Flow cytometric measurements conducted at intervals during the first year of exposure yielded cell cycle percentages of DNA (G0/G1, S, G2 + M phases) of rbc, as well as coefficients of variation (CV) in the G0/G1 phase. DNA histograms of exposed ducks were compared with two sets of controls which were maintained 30 and 150 miles from the study site. 137Cs live wholebody burdens were also measured in these animals in a parallel kinetics study, and an approximate steady-state equilibrium was attained after about 8 months. DNA histograms from 2 of the 14 contaminated ducks revealed DNA aneuploid-like patterns after 9 months exposure. These two ducks were removed from the experiment at this time, and when sampled again 1 month later, one continued to exhibit DNA aneuploidy. None of the control DNA histograms demonstrated DNA aneuploid-like patterns. There were no significant differences in cell cycle percentages at any time point between control and exposed animals. A significant increase in CV was observed at 9 months exposure, but after removal of the two ducks with DNA aneuploidy, no significant difference was detected in the group monitored after 12 months exposure. An increased variation in the DNA and DNA aneuploidy could, therefore, be detected in duck rbc using flow cytometric analysis, with the onset of these effects being related to the attainment of maximal levels of 137Cs body burdens in the exposed animals

  8. Quantitative transmission characteristics of different H5 low pathogenic avian influenza viruses in Muscovy ducks.

    Science.gov (United States)

    Niqueux, Éric; Picault, Jean-Paul; Amelot, Michel; Allée, Chantal; Lamandé, Josiane; Guillemoto, Carole; Pierre, Isabelle; Massin, Pascale; Blot, Guillaume; Briand, François-Xavier; Rose, Nicolas; Jestin, Véronique

    2014-01-10

    EU annual serosurveillance programs show that domestic duck flocks have the highest seroprevalence of H5 antibodies, demonstrating the circulation of notifiable avian influenza virus (AIV) according to OIE, likely low pathogenic (LP). Therefore, transmission characteristics of LPAIV within these flocks can help to understand virus circulation and possible risk of propagation. This study aimed at estimating transmission parameters of four H5 LPAIV (three field strains from French poultry and decoy ducks, and one clonal reverse-genetics strain derived from one of the former), using a SIR model to analyze data from experimental infections in SPF Muscovy ducks. The design was set up to accommodate rearing on wood shavings with a low density of 1.6 ducks/m(2): 10 inoculated ducks were housed together with 15 contact-exposed ducks. Infection was monitored by RNA detection on oropharyngeal and cloacal swabs using real-time RT-PCR with a cutoff corresponding to 2-7 EID50. Depending on the strain, the basic reproduction number (R0) varied from 5.5 to 42.7, confirming LPAIV could easily be transmitted to susceptible Muscovy ducks. The lowest R0 estimate was obtained for a H5N3 field strain, due to lower values of transmission rate and duration of infectious period, whereas reverse-genetics derived H5N1 strain had the highest R0. Frequency and intensity of clinical signs were also variable between strains, but apparently not associated with longer infectious periods. Further comparisons of quantitative transmission parameters may help to identify relevant viral genetic markers for early detection of potentially more virulent strains during surveillance of LPAIV. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Tropism and infectivity of duck-derived egg drop syndrome virus in chickens.

    Directory of Open Access Journals (Sweden)

    Min Kang

    Full Text Available Egg drop syndrome virus (EDSV can markedly decrease egg production in laying hens. Duck is the natural host of EDSV. EDSV derived from ducks abrogate egg drop in laying hens. We have previously confirmed that duck-derived EDSVs have a variety of replication activities in chick embryo liver (CEL cells. However, it is currently unclear whether duck-derived EDSV could display tropism and adaptation in laying hens. This study assessed whether duck-derived EDSV can adapt to laying hens, and estimated the inducing factors. Complete genome sequences of duck-derived EDSVs (D11-JW-012, D11-JW-017, and D11-JW-032 isolates with various replication efficiency in CEL cells and C10-GY-001 isolate causing disease in laying hens were analyzed to find their differences. Phylogenetic analysis of complete genome sequence revealed that C10-GY-001, D11-JW-032, and strain 127 virus as vaccine were clustered into the same group, with D11-JW-012 and D11-JW-017 clustered in another group. Comparison between D11-JW-012 isolate that poorly replicated and D11-JW-017 isolate that replicated well in CEL cells in same cluster revealed six amino acid differences on IVa2, DNA polymerase, endopeptidase, and DNA-binding protein. These amino acids might be key candidates enhancing cellular tropism in chicken. When the pathogenicities of these isolates in laying hens were compared, D11-JW-032 showed severe signs similar to 127 virus, D11-JW-017 showed intermediate signs, while D11-JW-012 showed almost no sign. Eleven amino acids differed between D11-JW-032 and D11-JW-017, and 17 amino acids were different between D11-JW-032 and D11-JW-012. These results suggest that EDSVs derived from ducks have various pathogenicities in laying hens. Key amino acid candidates might have altered their affinity to tropism of laying hens, causing difference pathogenicities.

  10. Isolation and characterization of a subtype C avian metapneumovirus circulating in Muscovy ducks in China.

    Science.gov (United States)

    Sun, Shikai; Chen, Feng; Cao, Sheng; Liu, Jiajia; Lei, Wen; Li, Guangwei; Song, Yongfeng; Lu, Junpeng; Liu, Chuang; Qin, Jianping; Li, Haiyan

    2014-07-25

    Subtype C avian metapneumovirus (aMPV-C), is an important pathogen that can cause egg-drop and acute respiratory diseases in poultry. To date, aMPV-C infection has not been documented in Muscovy ducks in China. Here, we isolated and characterized an aMPV-C, designated S-01, which has caused severe respiratory disease and noticeable egg drop in Muscovy duck flocks in south China since 2010. Electron microscopy showed that the isolate was an enveloped virus exhibiting multiple morphologies with a diameter of 20-500 nm. The S-01 strain was able to produce a typical cytopathic effect (CPE) on Vero cells and cause death in 10- to 11-day-old Muscovy duck embryos. In vivo infection of layer Muscovy ducks with the isolate resulted in typical clinical signs and pathological lesions similar to those seen in the original infected cases. We report the first complete genomic sequence of aMPV-C from Muscovy ducks. A phylogenetic analysis strongly suggested that the S-01 virus belongs to the aMPV-C family, sharing 92.3%-94.3% of nucleotide identity with that of aMPV-C, and was most closely related to the aMPV-C strains isolated from Muscovy ducks in France. The deduced eight main proteins (N, P, M, F, M2, SH, G and L) of the novel isolate shared higher identity with hMPV than with other aMPV (subtypes A, B and D). S-01 could bind a monoclonal antibody against the F protein of hMPV. Together, our results indicate that subtype-C aMPV has been circulating in Muscovy duck flocks in South China, and it is urgent for companies to develop new vaccines to control the spread of the virus in China.

  11. Phylogenetic relationships and pathogenicity variation of two Newcastle disease viruses isolated from domestic ducks in Southern China.

    Science.gov (United States)

    Kang, Yinfeng; Li, Yanling; Yuan, Runyu; Li, Xianwei; Sun, Minhua; Wang, Zhaoxiong; Feng, Minsha; Jiao, Peirong; Ren, Tao

    2014-08-12

    Newcastle disease (ND) is an OIE listed disease caused by virulent avian paramyxovirus type 1 (APMV-1) strains, which is enzootic and causes large economic losses in the poultry sector. Genotype VII and genotype IX NDV viruses were the predominant circulating genotype in China, which may possibly be responsible for disease outbreaks in chicken flocks in recent years. While ducks and geese usually have exhibited inapparent infections. In the present study, we investigate the complete genome sequence, the clinicopathological characterization and transmission of two virulent Newcastle disease viruses, SS-10 and NH-10, isolated from domestic ducks in Southern China in 2010. F, and the complete gene sequences based on phylogenetic analysis demonstrated that SS-10 (genotype VII) and NH-10 (genotype IX) belongs to class II. The deduced amino acid sequence was (112)R-R-Q-K/R-R-F(117) at the fusion protein cleavage site. Animal experiment results showed that the SS-10 virus isolated from ducks was highly pathogenic for chickens and geese, but low pathogenic for ducks. It could be detected from spleen, lung, kidney, trachea, small intestine, bursa of fabricius, thymus, pancreas and cecal tonsils, oropharyngeal and cloacal swabs, and could transmit to the naive contact birds. Moreover, it could transmit to chickens, ducks and geese by naive contact. However, the NH-10 virus isolated from ducks could infect some chickens, ducks and geese, but only caused chickens to die. Additionally, it could transmit to the naive contact chickens, ducks, and geese. The two NDV isolates exhibited different biological properties with respect to pathogenicity and transmission in chickens, ducks and geese. Therefore, no species-preference exists for chicken, duck or goose viruses and more attention should be paid to the trans-species transmission of VII NDVs between ducks, geese and chickens for the control and eradication of ND.

  12. The first whole genome sequence and pathogenicity characterization of a fowl adenovirus 4 isolated from ducks associated with inclusion body hepatitis and hydropericardium syndrome.

    Science.gov (United States)

    Pan, Qing; Liu, Linlin; Wang, Yongqiang; Zhang, Yanping; Qi, Xiaole; Liu, Changjun; Gao, Yulong; Wang, Xiaomei; Cui, Hongyu

    2017-10-01

    In June 2015, an infectious disease with high prevalence causing severe hydropericardium syndrome (HPS) first appeared in duck farms of northeast China. The disease showed high morbidity of 35% and mortality of 15% in a commercial duck farm with 200,000 45-day-old ducks. One strain of hypervirulent fowl adenovirus serotype 4 was identified and designated as HLJDAd15. The whole genome of the duck isolate was sequenced and found to contain the same large deletions as a genotype that has become prevalent in chickens in China recently, indicating that this disease might be transmitted from chickens to ducks. The pathogenicity of HLJDAd15 was evaluated in SPF chickens and ducks. The results showed that chickens were more susceptible to this new genotype of fowl adenovirus, and it was more difficult to infect ducks than chickens with the duck origin virus. Thus, it appears that this severe HPS in ducks is far more likely to have been transmitted from chickens to ducks than from ducks to ducks. Therefore, transmission from chickens to ducks constitutes a threat to the duck farming industry, and this transmission route is a very important consideration for the prevention and control of the new genotype of fowl adenovirus. This is the first whole genome sequence of a FAdV-4 isolated from ducks, and this information is important for understanding the molecular characteristics and evolution of aviadenoviruses. The potential risks of infection with this new hypervirulent FAdV-4 genotype in chickens and ducks urgently require an effective vaccine.

  13. Sea Ice Drift Monitoring in the Bohai Sea Based on GF4 Satellite

    Science.gov (United States)

    Zhao, Y.; Wei, P.; Zhu, H.; Xing, B.

    2018-04-01

    The Bohai Sea is the inland sea with the highest latitude in China. In winter, the phenomenon of freezing occurs in the Bohai Sea due to frequent cold wave influx. According to historical records, there have been three serious ice packs in the Bohai Sea in the past 50 years which caused heavy losses to our economy. Therefore, it is of great significance to monitor the drift of sea ice and sea ice in the Bohai Sea. The GF4 image has the advantages of short imaging time and high spatial resolution. Based on the GF4 satellite images, the three methods of SIFT (Scale invariant feature - the transform and Scale invariant feature transform), MCC (maximum cross-correlation method) and sift combined with MCC are used to monitor sea ice drift and calculate the speed and direction of sea ice drift, the three calculation results are compared and analyzed by using expert interpretation and historical statistical data to carry out remote sensing monitoring of sea ice drift results. The experimental results show that the experimental results of the three methods are in accordance with expert interpretation and historical statistics. Therefore, the GF4 remote sensing satellite images have the ability to monitor sea ice drift and can be used for drift monitoring of sea ice in the Bohai Sea.

  14. Contrasting nest survival patterns for ducks and songbirds in northern mixed-grass prairie

    Science.gov (United States)

    Grant, Todd; Shaffer, Terry L.; Madden, Elizabeth M.; Nenneman, Melvin P.

    2017-01-01

    Management actions intended to protect or improve habitat for ducks may benefit grassland-nesting passerines, but scant information is available to explore this assumption. During 1998–2003, we examined nest survival of ducks and songbirds to determine whether effects of prescribed fire and other habitat features (e.g., shrub cover and distance to habitat edges) were similar for ducks and passerines breeding in North Dakota. We used the logistic-exposure method to estimate survival of duck and songbird nests (n = 3,171). We used an information-theoretic approach to identify factors that most influenced nest survival. Patterns of nest survival were markedly different between taxonomic groups. For ducks, nest survival was greater during the first postfire nesting season (daily survival rate [DSR] = 0.957, 85% CI = 0.951–0.963), relative to later postfire nesting seasons (DSR = 0.946, 85% CI = 0.942–0.950). Furthermore duck nest survival and nest densities were inversely related. Duck nest survival also was greater as shrub cover decreased and as distance from cropland and wetland edges increased. Passerines had lower nest survival during the first postfire nesting season (DSR = 0.934, 85% CI = 0.924–0.944), when densities also were low compared to subsequent postfire nesting seasons (DSR = 0.947, 85% CI = 0.944–0.950). Parasitism by brown-headed cowbirds (Molothrus ater) reduced passerine nest survival and this effect was more pronounced during the first postfire nesting season compared to subsequent nesting seasons. Passerine nest survival was greater as shrub cover decreased and perhaps for more concealed nests. Duck and songbird nest survival rates were not correlated during this study and for associated studies that examined additional variables using the same dataset, suggesting that different mechanisms influenced their survival. Based on our results, ducks should not be considered direct surrogates for passerines

  15. Effect of dietary energy and protein content on growth and carcass traits of Pekin ducks.

    Science.gov (United States)

    Zeng, Q F; Cherry, P; Doster, A; Murdoch, R; Adeola, O; Applegate, T J

    2015-03-01

    A study was conducted to determine the influence of dietary energy and protein concentrations on growth performance and carcass traits of Pekin ducks from 15 to 35 d of age. In experiment 1, 14-d-old ducks were randomly assigned to 3 dietary metabolizable energy (11.8, 12.8, and 13.8 MJ/kg) and 3 crude protein concentrations (15, 17, and 19%) in a 3×3 factorial arrangement (6 replicate pens; 66 ducks/pen). Carcass characteristics were evaluated on d 28, 32, and 35. In Experiment 2, 15-d-old ducks (6 replicate cages; 6 ducks/cage) were randomly allotted to the 9 diets that were remixed with 0.5% chromic oxide. Excreta were collected from d 17 to 19, and ileal digesta was collected on d 19 to determine AMEn and amino acid digestibility. In Experiment 1, there were interactions (Pducks were fed a high dietary AMEn (13.75 MJ/kg) and high CP (19%, 1.21% SID Lys). These results provide a framework for subsequent modeling of amino acid and energy inputs and the corresponding outputs of growth performance and carcass components. © The Author 2015. Published by Oxford University Press on behalf of Poultry Science Association.

  16. Feeding Diets Containing Different Forms of Duckweed on Productive Performance and Egg Quality of Ducks

    Directory of Open Access Journals (Sweden)

    B. Indarsih

    2012-08-01

    Full Text Available The present experiment was undertaken to study the feeding effect of diets containing different forms of duckweed for local ducks on their productive performance and egg quality or egg yolk pigmentation. A total of 90 birds of 24 wk old ducks were randomly divided into 18 experimental units of 2.0 x 1.0 m2 of cages. The experiment was assigned in a completely randomized design (3 treatments with 6 replicates, 5 birds each. There were 3 dietary treatments, namely P1= ducks fed a complete diet containing 20 % of dried duckweed and given in the form of dry-mash; P2= a complete diet in P1 but it was offered in wet form (slurry; and P3= ducks were offered basal diet in the form of dry-mash and fresh duckweed was offered separately ad libitum. Diets were formulated to have similar nutritional contents. Feed consumption, feed conversion ratio (FCR, and egg yolk pigmentation were measured. The result of the study showed that these three parameters were affected by the feeding different forms of duckweed. Feeding diet with fresh duckweed brought about the best pigmentation than did the dry one. Fresh duckweed offers a promise as a potential feedstuff for ducks and has a good implication in reducing feed processing cost.

  17. Nutritive Value of Fermented Water Hyacinth (Eichornia crassipes Leaf with Aspergillus niger in Tegal Duck

    Directory of Open Access Journals (Sweden)

    I Mangisah

    2010-05-01

    Full Text Available Two steps of experiment were conducted to evaluate the proximate composition and nutritive value of fermented water hyacinth leaf (WHL with Aspergillus niger in Tegal duck. Twenty two heads of eight-week Tegal ducks with an average body weight of 1202.55 + 111.14 g were used in this experiment. There were two treatments namely: non-fermented (NFWH and fermented with Aspergillus niger (FWHAN. Each treatment was replicated 10 times. Data gathered were analyzed using t-student test. The proximate composition between NFWH and FWHAN showed an increase in crude protein/CP (11.44 vs 16.09% and ash (12.76 vs 22.37% but a decrease in crude fiber/CF (21.51 vs 16.62% and nitrogen free extract/NFE (53.20 vs 43.59%. The nutritive value of diet for eight-week Tegal ducks showed that fermentation of WHL with Aspergillus niger significantly increased CP digestibility, true metabolizable energy (TME and nitrogen retention (NR, but not for CF digestibility. It could be concluded that fermentation of WHL with Aspergillus niger increases the nutrient quality and the nutritive value of diet for eight-week Tegal ducks in term of CP digestibility, TME and NR. (Animal Production 12(2: 100-104 (2010Key Words: water hyacinth leaf, fermentation, Aspergillus niger, biological value, Tegal ducks

  18. QUALITY AND SHELF LIFE EVALUATION OF NUGGETS PREPARED FROM SPENT DUCK AND SPENT HEN MEAT

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar

    2015-12-01

    Full Text Available A study was conducted to compare the quality of nuggets prepared from spent hen and duck meat. The cooked nuggets were analyzed for pH, thiobarbituric acid (TBA, tyrosine value (TV, moisture, fat, protein, total plate count (TPC and sensory evaluations. Nuggets prepared from spent hen meat showed significantly higher (p<0.05 moisture content however pH, fat and protein content were significantly higher (p<0.05 in duck nuggets. TBA values, TVs and (TPC were highest in duck nuggets but were within the acceptable level up to 7th day of refrigerated storage (4±1°C in both types of nuggets. Both nuggets maintain their sensory quality up to 7th day of refrigeration storage but spent hen nuggets were preferred by consumers compared to nuggets prepared from spent duck meat. Result of the study indicated that, despite the comparative differences among these nuggets, spent duck and hen meat could be used for preparation of nutritionally rich and acceptable nuggets.

  19. DNA microarray global gene expression analysis of influenza virus-infected chicken and duck cells

    Directory of Open Access Journals (Sweden)

    Suresh V. Kuchipudi

    2015-06-01

    Full Text Available The data described in this article pertain to the article by Kuchipudi et al. (2014 titled “Highly Pathogenic Avian Influenza Virus Infection in Chickens But Not Ducks Is Associated with Elevated Host Immune and Pro-inflammatory Responses” [1]. While infection of chickens with highly pathogenic avian influenza (HPAI H5N1 virus subtypes often leads to 100% mortality within 1 to 2 days, infection of ducks in contrast causes mild or no clinical signs. The rapid onset of fatal disease in chickens, but with no evidence of severe clinical symptoms in ducks, suggests underlying differences in their innate immune mechanisms. We used Chicken Genechip microarrays (Affymetrix to analyse the gene expression profiles of primary chicken and duck lung cells infected with a low pathogenic avian influenza (LPAI H2N3 virus and two HPAI H5N1 virus subtypes to understand the molecular basis of host susceptibility and resistance in chickens and ducks. Here, we described the experimental design, quality control and analysis that were performed on the data set. The data are publicly available through the Gene Expression Omnibus (GEOdatabase with accession number GSE33389, and the analysis and interpretation of these data are included in Kuchipudi et al. (2014 [1].

  20. THE EFFECT OF CALCIUM AND PHOSPHORUS DIETARY LEVEL ON EGG PRODUCTION OF THE BANTUL LOCAL DUCK

    Directory of Open Access Journals (Sweden)

    H. Sasongko

    2014-10-01

    Full Text Available This study was conducted to determine the effect of various calcium and phosphorus levels on theproduction performance of Bantul Duck. A total of 270 female ducks, 26 weeks age, were used in thestudy with a 3x3 factorial treatment, which is a combination of three levels of Ca: 3.75; 3.25 and 2.75%and three levels of P: 0.45, 0.35 and 0.25%. Each treatment occupied three replication cages, each ofwhich consisted of 10 ducks. The experiment was conducted for 12 weeks.. Data recorded were: (a feedintake (g/duck/day, (b egg production (% HDA, and (c feed conversion. All quantitative dataobtained during the study were analyzed by analysis of variance (ANOVA using SPSS computerprogram. The results of the variables recorded did not show significantly difference. Increasing Ca levelon feed showed an increasing trend of egg production. The average feed consumption ranged at 151-159g/duck/day; egg production was 75-84%, and the feed conversion was 184-212 g/egg.

  1. THE EFFECT OF CALCIUM AND PHOSPHORUS DIETARY LEVEL ON EGG PRODUCTION OF THE BANTUL LOCAL DUCK

    Directory of Open Access Journals (Sweden)

    H. Sasongko

    2012-12-01

    Full Text Available This study was conducted to determine the effect of various calcium and phosphorus levels on the production performance of Bantul Duck. A total of 270 female ducks, 26 weeks age, were used in the study with a 3x3 factorial treatment, which is a combination of three levels of Ca: 3.75; 3.25 and 2.75% and three levels of P: 0.45, 0.35 and 0.25%. Each treatment occupied three replication cages, each of which consisted of 10 ducks. The experiment was conducted for 12 weeks.. Data recorded were: (a feed intake (g/duck/day, (b egg production (% HDA, and (c feed conversion. All quantitative data obtained during the study were analyzed by analysis of variance (ANOVA using SPSS computer program. The results of the variables recorded did not show significantly difference. Increasing Ca level on feed showed an increasing trend of egg production. The average feed consumption ranged at 151-159 g/duck/day; egg production was 75-84%, and the feed conversion was 184-212 g/egg.

  2. Mechanism and capacities of reducing ecological cost through rice-duck cultivation.

    Science.gov (United States)

    Long, Pan; Huang, Huang; Liao, Xiaolan; Fu, Zhiqiang; Zheng, Huabin; Chen, Aiwu; Chen, Can

    2013-09-01

    Rice-duck cultivation is the essence of Chinese traditional agriculture. A scientific assessment of the mechanism and its capacity is of theoretical significance and practical value in improving modern agricultural technology. The duck's secretions, excreta and their treading, pecking and predation decrease the occurrence of plant diseases, pests and weeds, enrich species diversity and improve the field environment. The rice-duck intergrowth system effectively prevents rice planthoppers and rice leafhoppers. The control effects can be up to 98.47% and 100% respectively; it also has effects on the control of Chilo suppressalis, Tryporyza incertulas and the rice leafrollers. Notable control results are found on sheath blight, while the effects on other diseases are about 50%. Harm from weeds is placed under primary control; prevention of weeds is sequenced by broadleaf weeds > sedge weeds > Gramineae weeds. Contents of soil organic matter, N, P and K are improved by the system; nutrient utilization is accelerated, resulting in decreased fertilizer application. Greenhouse gas emissions are reduced by 1-2% and duck fodder is saved in this system. There is also an obvious economic benefit. Compared to conventional rice cultivation, rice-duck cultivation shows great benefits to ecologic cost and economic income. © 2013 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  3. Communicating Certainty About Nuclear Winter

    Science.gov (United States)

    Robock, A.

    2013-12-01

    I have been spending much of my time in the past several years trying to warn the world about the continuing danger of nuclear weapons, and that the solution is a rapid reduction in the nuclear arsenal. I feel that a scientist who discovers dangers to society has an ethical duty to issue a warning, even if the danger is so scary that it is hard for people to deal with. The debate about nuclear winter in the 1980s helped to end the nuclear arms race, but the planet still has enough nuclear weapons, even after reductions planned for 2017 under the New START treaty, to produce nuclear winter, with temperatures plunging below freezing in the summer in major agricultural regions, threatening the food supply for most of the planet. New research by myself, Brian Toon, Mike Mills, and colleagues over the past six years has found that a nuclear war between any two countries, such as India and Pakistan, using 50 atom bombs each of the size dropped on Hiroshima could produce climate change unprecedented in recorded human history, and a world food crisis because of the agricultural effects. This is much less than 1% of the current global arsenal. Communicating certainty - what we know for sure - has been much more effective than communicating uncertainty. The limited success I have had has come from persistence and serendipity. The first step was to do the science. We have published peer-reviewed articles in major journals, including Science, Nature, Proceedings of the National Academy of Sciences, Journal of Geophysical Research, Atmospheric Chemistry and Physics, Physics Today, and Climatic Change. But policymakers do not read these journals. Through fairly convoluted circumstances, which will be described in this talk, we were able to get papers published in Scientific American and the Bulletin of Atomic Scientists. I have also published several encyclopedia articles on the subject. As a Lead Author of Chapter 8 (Radiative Forcing) of the recently published Fifth Assessment

  4. Surface wind energy trends near Taiwan in winter since 1871

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2017-01-01

    Full Text Available The tropical surface wind speed in boreal winter reaches a maximum near Taiwan. This stable wind resource may be used for future clean energy development. How this surface wind energy source has changed in past 141 years is investigated using the 20th century reanalysis dataset and CMIP5 models. Our observational analysis shows that the surface wind speed experienced a weakening trend in the past 141 years (1871 - 2010. The average decreasing rate is around -1.4 m s-1 per century. The decrease is primarily attributed to the relative sea surface temperature (SST cooling in the subtropical North Pacific, which forces a large-scale low-level anti-cyclonic circulation anomaly in situ and is thus responsible for the southerly trend near Taiwan. The relative SST trend pattern is attributed mainly to the greenhouse gas effect associated with anthropogenic activities. The southerly trend near Taiwan is more pronounced in the boreal winter than in summer. Such seasonal difference is attributed to the reversed seasonal mean wind, which promotes more efficient positive feedback in the boreal winter. The CMIP5 historical run analysis reveals that climate models capture less SST warming and large-scale anti-cyclonic circulation in the subtropical North Pacific, but the simulated weakening trend of the surface wind speed near Taiwan is too small.

  5. Molecular characterization, phylogeny analysis and pathogenicity of a Muscovy duck adenovirus strain isolated in China in 2014

    International Nuclear Information System (INIS)

    Zhang, Xinheng; Zhong, Yangjin; Zhou, Zhenhai; Liu, Yang; Zhang, Huanmin; Chen, Feng; Chen, Weiguo; Xie, Qingmei

    2016-01-01

    This study aimed to characterize a novel adenovirus (AdV) isolated from diseased Muscovy ducks in China. After the AdV was successfully propagated in duck embryo fibroblasts, the morphological and physicochemical properties of the virions were studied by electron microscopy and different tests. The results of the analyses were in conformity with AdV properties. The full genome sequence was determined and analyzed. The new isolate (named CH-GD-12-2014) shared over 91% sequence identity with duck AdV-2 representing the species Duck aviadenovirus B. The most important distinguishing feature between the two DAdV strains was the presence of a second fiber gene in the Chinese isolate. Phylogeny reconstruction confirmed the affiliation of the virus with goose and duck AdVs in the genus Aviadenovirus. Experimental infection resulted in embryo death, and intramuscular inoculation provoked morbidity and mortality among ducks and chickens. - Highlights: • A duck adenovirus type 3 was isolated and the complete genome of DAdV-3 was obtained. • Physicochemical properties and electron microscopy were researched. • Pathogenicity of duck adenovirus type 3 was researched.

  6. Molecular characterization, phylogeny analysis and pathogenicity of a Muscovy duck adenovirus strain isolated in China in 2014

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xinheng [College of Animal Science, South China Agricultural University & Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Guangzhou 510642 (China); Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangzhou, Guangdong 510642 (China); South China Collaborative Innovation Center for Poultry Disease Control and Product Safety, Guangzhou 510642 (China); Zhong, Yangjin; Zhou, Zhenhai; Liu, Yang [College of Animal Science, South China Agricultural University & Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Guangzhou 510642 (China); Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangzhou, Guangdong 510642 (China); Zhang, Huanmin [USDA, Agriculture Research Service, Avian Disease and Oncology Laboratory, East Lansing, MI 48823 (United States); Chen, Feng [College of Animal Science, South China Agricultural University & Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Guangzhou 510642 (China); Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangzhou, Guangdong 510642 (China); Chen, Weiguo [College of Animal Science, South China Agricultural University & Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Guangzhou 510642 (China); Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangzhou, Guangdong 510642 (China); South China Collaborative Innovation Center for Poultry Disease Control and Product Safety, Guangzhou 510642 (China); Xie, Qingmei, E-mail: qmx@scau.edu.cn [College of Animal Science, South China Agricultural University & Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, Guangzhou 510642 (China); Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangzhou, Guangdong 510642 (China); South China Collaborative Innovation Center for Poultry Disease Control and Product Safety, Guangzhou 510642 (China)

    2016-06-15

    This study aimed to characterize a novel adenovirus (AdV) isolated from diseased Muscovy ducks in China. After the AdV was successfully propagated in duck embryo fibroblasts, the morphological and physicochemical properties of the virions were studied by electron microscopy and different tests. The results of the analyses were in conformity with AdV properties. The full genome sequence was determined and analyzed. The new isolate (named CH-GD-12-2014) shared over 91% sequence identity with duck AdV-2 representing the species Duck aviadenovirus B. The most important distinguishing feature between the two DAdV strains was the presence of a second fiber gene in the Chinese isolate. Phylogeny reconstruction confirmed the affiliation of the virus with goose and duck AdVs in the genus Aviadenovirus. Experimental infection resulted in embryo death, and intramuscular inoculation provoked morbidity and mortality among ducks and chickens. - Highlights: • A duck adenovirus type 3 was isolated and the complete genome of DAdV-3 was obtained. • Physicochemical properties and electron microscopy were researched. • Pathogenicity of duck adenovirus type 3 was researched.

  7. The Birth of a research animal. Ibsen's The Wild Duck and the origin of a new animal science

    NARCIS (Netherlands)

    Zwart, H.A.E.

    2000-01-01

    What role does the wild duck play in Ibsen's famous drama? I argue that, besides mirroring the fate of the human cast members, the duck is acting as animal subject in a quasi-experiment, conducted in a private setting. Analysed from this perspective, the play allows us to discern the epistemological

  8. A Feasibility Study of Sustainable Distributed Generation Technologies to Improve the electrical System on the Duck Valley Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Herman Atkins, Shoshone-Paiute; Mark Hannifan, New West Technologies

    2005-06-30

    A range of sustainable energy options were assessed for feasibility in addressing chronic electric grid reliability problems at Duck Valley IR. Wind power and building energy efficiency were determined to have the most merit, with the Duck Valley Tribes now well positioned to pursue large scale wind power development for on- and off-reservation sales.

  9. Establishment of an H6N2 Influenza Virus Lineage in Domestic Ducks in Southern China ▿ †

    Science.gov (United States)

    Huang, K.; Bahl, J.; Fan, X. H.; Vijaykrishna, D.; Cheung, C. L.; Webby, R. J.; Webster, R. G.; Chen, H.; Smith, Gavin J. D.; Peiris, J. S. M.; Guan, Y.

    2010-01-01

    Multiple reassortment events between different subtypes of endemic avian influenza viruses have increased the genomic diversity of influenza viruses circulating in poultry in southern China. Gene exchange from the natural gene pool to poultry has contributed to this increase in genetic diversity. However, the role of domestic ducks as an interface between the natural gene pool and terrestrial poultry in the influenza virus ecosystem has not been fully characterized. Here we phylogenetically and antigenically analyzed 170 H6 viruses isolated from domestic ducks from 2000 to 2005 in southern China, which contains the largest population of domestic ducks in the world. Three distinct hemagglutinin lineages were identified. Group I contained the majority of isolates with a single internal gene complex and was endemic in domestic ducks in Guangdong from the late 1990s onward. Group II was derived from reassortment events in which the surface genes of group I viruses were replaced with novel H6 and N2 genes. Group III represented H6 viruses that undergo frequent reassortment with multiple virus subtypes from the natural gene pool. Surprisingly, H6 viruses endemic in domestic ducks and terrestrial poultry seldom reassort, but gene exchanges between viruses from domestic ducks and migratory ducks occurred throughout the surveillance period. These findings suggest that domestic ducks in southern China mediate the interaction of viruses between different gene pools and facilitate the generation of novel influenza virus variants circulating in poultry. PMID:20463062

  10. Molecular characterization, phylogeny analysis and pathogenicity of a Muscovy duck adenovirus strain isolated in China in 2014

    Science.gov (United States)

    This study aimed to characterize a novel adenovirus (AdV) isolated from diseased Muscovy ducks in China. After the AdV was successfully propagated in duck embryo fibroblasts, the morphological and physicochemical properties of the virions were studied by electron microscopy and different tests. The ...

  11. Effects of dirty snow in nuclear winter simulations

    International Nuclear Information System (INIS)

    Vogelmann, A.M.; Robock, A.; Ellingson, R.G.

    1988-01-01

    A large-scale nuclear war would inject smoke into the atmosphere from burning forests, cities, and industries in targeted areas. This smoke could fall out onto snow and ice and would lower cryospheric albedos by as much as 50%. A global energy balance climate model is used to investigate the maximum effect these ''dirty snow'' albedos have on the surface temperature in nuclear winter simulations which span several years. These effects are investigated for different nuclear winter scenarios, snow precipitation rates, latitudinal distributions of smoke, and seasonal timings. We find that dirty snow, in general, would have a small temperature effect at mid- and low latitudes but could have a large temperature effect at polar latitudes, particularly if the soot is able to reappear significantly in later summers. Factors which limit the climatic importance of the dirty snow are (1) the dirty snow albedo is lowest when the atmosphere still contains a large amount of light-absorbing smoke; (2) even with dirty snow, sea ice areas can still increase, which helps maintain colder temperatures through the sea ice thermal inertial feedback; (3) the snow and ice areas affected by the dirty snow albedos are largest when there is little seasonal solar insolation; and (4) the area affected by the dirty snow is relatively small under all circumstances. copyright American Geophysical Union 1988

  12. Failure to transmit avian vacuolar myelinopathy to mallard ducks

    Science.gov (United States)

    Larsen, R.S.; Nutter, F.B.; Augspurger, T.; Rocke, T.E.; Thomas, N.J.; Stoskopf, M.K.

    2003-01-01

    Avian vacuolar myelinopathy (AVM) is a neurologic disease that has been diagnosed in free-ranging birds in the southeastern United States. Bald eagles (Haliaeetus leuocephalus), American coots (Fulica americana), and mallards (Anas platyrhynchos) have been affected. Previous investigations have not determined the etiology of this disease. In November and December 2002, we attempted to induce AVM in game-farmed mallards through four, 7-day exposure trials. Mallards were housed in six groups of eight, with two of these groups serving as controls. One group was housed with AVM-affected coots; one group was tube fed daily with water from the lake where affected coots were captured; one group was tube fed daily with aquatic vegetation (Hydrilla verticillata) from the same lake; and another group was tube fed daily with sediment from the lake. No ducks exhibited clinical neurologic abnormalities consistent with AVM and no evidence of AVM was present at histopathologic examination of brain tissue. Although limitations in sample size, quantity of individual doses, frequency of dose administration, duration of exposure, and timing of these trials restrict the interpretation of the findings, AVM was not readily transmitted by direct contact, water, hydrilla, or sediment in this investigation.

  13. Red fox prey demands and implications to prairie duck production

    Science.gov (United States)

    Sargeant, A.B.

    1978-01-01

    Experiments were conducted during spring and summer with 33 red foxes (Vulpes vulpes) to determine prey demands, feeding characteristics, and growth rates using natural foods. Pups began eating prey the 4th week after birth. Then, prey consumption averaged 1.38 and 1.90 kg/pup/week for weeks 5-8 and 9-12 of the denning season respectively, and 2.54 kg/pup/week for the postdenning period. Feeding by adults averaged 2.25 kg/adult/week. Free water was not needed by either pups or adults. About 90 percent of the prey offered to pups on simulated natural diets was consumed, remains varied with prey availability and prey type. Prey biomass required by a typical fox family was estimated at 18.5 kg/km2 for the 12-week denning season and 2.4 kg/km2/week for the postdenning period. Because of the large prey demands, ducks could represent a small part of the foxes' diet and yet be of consequence to the productivity of particular species. An example is provided for the mallard (Anas platyrhynchos).

  14. Sublethal effects of cadmium ingestion on mallard ducks. [Anas platyrhynchos

    Energy Technology Data Exchange (ETDEWEB)

    Di Giulio, R T; Scanlon, P F

    1984-11-01

    Juvenile mallard (Anas platyrhynchos) drakes were fed diets containing 0, 50, 150, or 450 ppM cadmium for 42 +/- 1 days in order to assess the impacts of cadmium ingestion on energy metabolism and tissue metal concentrations in this species. Most significant effects on energy metabolism were observed only in the 450 ppM group which displayed reduced body and liver weights, increased kidney weights, reduced liver aldolase activity, increased plasma concentrations of uric acid, decreased plasma triiodothyronine concentrations, and elevated adrenal weights and adrenal corticosterone concentrations. Ducks in the 150 ppM group displayed increased adrenal and kidney weights and elevated plasma nonesterified fatty acid concentrations. Among all treatments, increased cadmium and zinc concentrations in both livers and kidneys were dose-related; a similar trend was observed for copper concentrations in kidneys but not livers. Cadmium interference with carbohydrate metabolism in similar studies with mammals was more severe than that observed in mallards in the present study. 52 references, 6 tables.

  15. Feeding ducks, bacterial chemotaxis, and the Gini index

    Science.gov (United States)

    Peaudecerf, François J.; Goldstein, Raymond E.

    2015-08-01

    Classic experiments on the distribution of ducks around separated food sources found consistency with the "ideal free" distribution in which the local population is proportional to the local supply rate. Motivated by this experiment and others, we examine the analogous problem in the microbial world: the distribution of chemotactic bacteria around multiple nearby food sources. In contrast to the optimization of uptake rate that may hold at the level of a single cell in a spatially varying nutrient field, nutrient consumption by a population of chemotactic cells will modify the nutrient field, and the uptake rate will generally vary throughout the population. Through a simple model we study the distribution of resource uptake in the presence of chemotaxis, consumption, and diffusion of both bacteria and nutrients. Borrowing from the field of theoretical economics, we explore how the Gini index can be used as a means to quantify the inequalities of uptake. The redistributive effect of chemotaxis can lead to a phenomenon we term "chemotactic levelling," and the influence of these results on population fitness are briefly considered.

  16. Breeding ecology of the redhead duck in western Montana

    Science.gov (United States)

    Lokemoen, J.T.

    1966-01-01

    The habits of the redhead duck (Aythya americana) were studied in the Flathead Valley of western Montana in 1960 and 1961 to determine their habitat preferences in this pothole breeding ground. The 2,600-acre study area, surrounding the Ninepipe Reservoir, contained 686 potholes. Redheads usually were paired by the time they arrived on the study area in March. The average density of redhead breeding pairs was 25 pairs per square mile. For all spring activities except nesting, the birds used large, deep, open potholes or breeding-pair potholes. The several breeding-pair potholes and the nesting pothole utilized by the pair comprised their home range. Starting in late April, the pairs moved about the home range as the hens selected nesting sites, usually in the dense emergent vegetation of small, shallow potholes. Hard-stem bulrush (Scirpus acutus) and cat-tail (Typha latifolia) were preferred nesting cover. Redhead nesting success was only 15 percent, a low rate apparently caused by degenerate nesting behavior complicated by high redhead density, a lack of suitable nest hosts, and certain habitat deficiencies. By late June most drakes and unsuccessful hens had moved from the potholes to nearby reservoirs. All successful hens led their newly hatched broods from the nesting potholes to larger brood potholes and many eventually moved to the reservoir. By mid-July virtually all redheads had moved from the potholes to the reservoirs, where they remained until fall migration.

  17. Duck Valley Habitat Enhancement and Protection, 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Dodson, Guy; Pero, Vincent (Shoshone-Paiute Nation, Duck Valley Indian Reservation, Owyhee, NV)

    2000-01-01

    The Duck Valley Indian Reservations' Habitat Enhancement project is an ongoing project designed to enhance and protect the critical riparian areas, natural springs, and native fish spawning areas on the Reservation. The project was begun in 1997 with the hiring of a fisheries biologist and the creation of a new department for the Tribes. The project's goals are to protect and enhance the springs, Owyhee River, its tributaries, and to develop a database that can be used by other fisheries professionals which includes information on water quality and fish composition, health, abundance, and genetic makeup. One habitat portion of the project is a focus on protection the numerous springs that provide clean, cool water to the Owyhee River. This will be accomplished through enclosure fences of the spring heads and water troughs to provide clean cool drinking water for wildlife and livestock. Another habitat portion of the project involves protecting headwater areas of streams with native fish populations. This is accomplished through enclosure fencing and riparian plantings on any eroded or degraded banks in the enclosure area. Finally, we monitor and evaluate the areas protected and enhanced. This is accomplished through biological sampling for temperature, Oxygen, sedimentation, and measurements of water depth, bank height and undercut, and width of stream. With the habitat and biological indices we will be able to evaluate how well protective measures are doing, and where to focus future efforts.

  18. Discussing implications of fast depleting rural ponds on the globally threatened wetland winter migratory bird in Haryana: a Case Study of Nigdu village pond in Karnal District

    Directory of Open Access Journals (Sweden)

    Rohtash Chand Gupta

    2013-05-01

    Full Text Available The Nigdu-Sarovar is located in Nilokheri block in Karnal district in Haryana (29°50′N 76°55′E. The duration of observations span over seven years (September, 2005 to March, 2012. The recording of wetland winter visitor birds during 2005-08 in winter season included atleast 58 species of birds belonging to 10 orders and 18 families. It is important to mention that 29 species of wetland birds were winter migratory, 17 residents, 9 local migratory and three species of wetland birds like Lesser-whistling Duck Dendrocygna javanica, Pheasant-tailed Jacana Hydrophasianus chirurgus and Blue-cheeked Bee-eater Merops persicus were summer migratory. The special features of 2005-06 winter was the huge populations of birds like Northern Shoveller Anas clypeata, Northern Pintail Anas acuta, Common Teal Anas crecca, Spot-billed Duck Anas poecilorhynchus, Common Pochard Aythya ferina, Bar-headed Goose Anser indicus, Greylag Goose Anser anser, Gadwall Anas strepera, Great Cormorant Phalacrocorax carbo, Mallard Anas platyrhynchos and Common Redshank Tringa totanus etc.In successive years, the scenario was more or less a substantial one depicting stability with respect to diversity of birds, number of birds upto the year of 2008. The popular birds included Painted Stork Mycteria leucocephala, Openbill Stork Anastomus oscitans, White-necked Stork Ciconia episcopus, Black-necked Stork Ephippiorhynchus asiaticus, Eurasian Spoonbill Platalea leucorodia, Spotted Greenshank Tringa guttifer and Kentish Plover Charadrius alexandrines. The sharp decline in winter migratory birds at “Nigdu-Sarovar” started in the year of 2008 when the pond was leased out for FISH-FARMING as per the policies of Govt. of Haryana. Fish Farming based deepening of the pond by excavation of bottom resulting in total decimation of rooted, floating, submerged and ejecting plants along with its subsidiary fauna, Zooplanktons, phytoplankton etc. The age old structural regime of the pond

  19. Genetic characterization of a potentially novel goose parvovirus circulating in Muscovy duck flocks in Fujian Province, China.

    Science.gov (United States)

    Wang, Shao; Cheng, Xiao-Xia; Chen, Shao-Ying; Zhu, Xiao-Li; Chen, Shi-Long; Lin, Feng-Qiang; Li, Zhao-Long

    2013-01-01

    We report a novel goose parvovirus (MDGPV/PT) isolated from an affected Muscovy duck in Fujian Province, China. In this study, the NS1 sequence analyses indicated a close genetic relationship between MDGPV/PT and Muscovy duck parvovirus (MDPV) strains, although MDGPV/DY, which was isolated from a Muscovy duck in 2006 in Sichuan Province, could be divided into GPV-related groups. Phylogenetic analysis showed that except for differences in the NS1 gene, MDGPV strains PT and DY are closely related to a parvovirus that infects domestic waterfowls. This is the first demonstration of recombination between goose and Muscovy duck parvoviruses in nature, and MDGPV/PT might have led to the generation of a novel waterfowl parvovirus strain circulating in Muscovy duck flocks in China.

  20. Attribution of UK Winter Floods to Anthropogenic Forcing

    Science.gov (United States)

    Schaller, N.; Alison, K.; Sparrow, S. N.; Otto, F. E. L.; Massey, N.; Vautard, R.; Yiou, P.; van Oldenborgh, G. J.; van Haren, R.; Lamb, R.; Huntingford, C.; Crooks, S.; Legg, T.; Weisheimer, A.; Bowery, A.; Miller, J.; Jones, R.; Stott, P.; Allen, M. R.

    2014-12-01

    Many regions of southern UK experienced severe flooding during the 2013/2014 winter. Simultaneously, large areas in the USA and Canada were struck by prolonged cold weather. At the time, the media and public asked whether the general rainy conditions over northern Europe and the cold weather over North America were caused by climate change. Providing an answer to this question is not trivial, but recent studies show that probabilistic event attribution is feasible. Using the citizen science project weather@home, we ran over 40'000 perturbed initial condition simulations of the 2013/2014 winter. These simulations fall into two categories: one set aims at simulating the world with climate change using observed sea surface temperatures while the second set is run with sea surface temperatures corresponding to a world that might have been without climate change. The relevant modelled variables are then downscaled by a hydrological model to obtain river flows. First results show that anthropogenic climate change led to a small but significant increase in the fractional attributable risk for 30-days peak flows for the river Thames. A single number can summarize the final result from probabilistic attribution studies indicating, for example, an increase, decrease or no change to the risk of the event occurring. However, communicating this to the public, media and other scientists remains challenging. The assumptions made in the chain of models used need to be explained. In addition, extreme events, like the UK floods of the 2013/2014 winter, are usually caused by a range of factors. While heavy precipitation events can be caused by dynamic and/or thermodynamic processes, floods occur only partly as a response to heavy precipitation. Depending on the catchment, they can be largely due to soil properties and conditions of the previous months. Probabilistic attribution studies are multidisciplinary and therefore all aspects need to be communicated properly.

  1. South-coast cyclone in Japan during El Niño-caused warm winters

    Science.gov (United States)

    Ueda, Hiroaki; Amagai, Yuusuke; Hayasaki, Masamitsu

    2017-05-01

    La Niña conditions during boreal winter sometimes brings excessive snowfall in Japan, especially on the East Sea/Sea of Japan coastal and mountain areas through intensified northwesterly cold winds caused by La-Niña related atmospheric teleconnection. Meanwhile, snowfall events also increase in the Pacific coast area of Japan during the El Niño state due to extratropical cyclones passing along the south coast of Japan (hereafter referred to as South-coast cyclone). In the present study, we investigated year-to-year snowfall/rainfall variations based on meteorological station data and cyclone tracks identified by using the Japanese 55-year Reanalysis. The result clearly indicates increase of the South-coast cyclone during El Niño-developing winters, which is consistent with excessive snow-fall in the northern part of the Pacific coast. Strong subtropical jet hampers cyclogenesis due to less vertical interaction through the trapping of upper-level eddies. During El Niño-developing winters, the subtropical jet is weakened over East Asia, indicating dynamic linkage to increased cyclone frequency. In addition to this, both the deepening of the upper-tropospheric trough over East Asia and anomalous low-tropospheric northwest anticyclones extending from the Philippines toward Japan are also consistent with the enhancement of cyclogenesis over the East China Sea as well as warm winter in Japan.

  2. Does winter region affect spring arrival time and body mass of king eiders in northern Alaska?

    Science.gov (United States)

    Powell, Abby N.; Oppel, Steffen

    2009-01-01

    Events during the non-breeding season may affect the body condition of migratory birds and influence performance during the following breeding season. Migratory birds nesting in the Arctic often rely on endogenous nutrients for reproductive efforts, and are thus potentially subject to such carry-over effects. We tested whether king eider (Somateria spectabilis) arrival time and body mass upon arrival at breeding grounds in northern Alaska were affected by their choice of a winter region in the Bering Sea. We captured birds shortly after arrival on breeding grounds in early June 2002–2006 at two sites in northern Alaska and determined the region in which individuals wintered using satellite telemetry or stable isotope ratios of head feathers. We used generalized linear models to assess whether winter region explained variation in arrival body mass among individuals by accounting for sex, site, annual variation, and the date a bird was captured. We found no support for our hypothesis that either arrival time or arrival body mass of king eiders differed among winter regions. We conclude that wintering in different regions in the Bering Sea is unlikely to have reproductive consequences for king eiders in our study areas.

  3. Winter therapy for the accelerators

    CERN Multimedia

    Corinne Pralavorio

    2016-01-01

    Hundreds of people are hard at work during the year-end technical stop as all the accelerators are undergoing maintenance, renovation and upgrade operations in parallel.   The new beam absorber on its way to Point 2 before being lowered into the LHC tunnel for installation. The accelerator teams didn’t waste any time before starting their annual winter rejuvenation programme over the winter. At the end of November, as the LHC ion run was beginning, work got under way on the PS Booster, where operation had already stopped. On 14 December, once the whole complex had been shut down, the technical teams turned their attention to the other injectors and the LHC. The year-end technical stop (YETS) provides an opportunity to carry out maintenance work on equipment and repair any damage as well as to upgrade the machines for the upcoming runs. Numerous work projects are carried out simultaneously, so good coordination is crucial. Marzia Bernardini's team in the Enginee...

  4. The Effect of Zingiber Officinale Rosc in The Diets of Performance in Culled Layer Ducks

    Directory of Open Access Journals (Sweden)

    Tjokorda Gede Belawa Yadnya

    2012-02-01

    Full Text Available The experiment was design using a completely randomized block design (CRBD with four treatments. Treatment were diets without Zingiber officinale rosc (A, diets contain 2,91% Zingiber officinale Rosc  (B, diets contain 5,66%. Zingiber officinale Rosc (C, and diets contain 8,26% Zingiber officinale Rosc (D. Each treatment with five replicates, and each replicate consist four culled layer ducks. Variable observed were feed conversation ratio, carcass physical composition, and meat quality. It was concluded that present  Zingiber officinale Rosc in the diets could be improved of performance in culled layer ducks.   Keywords : Zingiber officinale Rosc, Culled layer ducks, and  meat qualit

  5. Effects of stocking density on growth performance, meat quality and tibia development of Pekin ducks.

    Science.gov (United States)

    Zhang, Ya Ru; Zhang, Lu Shuang; Wang, Zhong; Liu, Yang; Li, Fu Huang; Yuan, Jian Min; Xia, Zhao Fei

    2018-06-01

    This study was performed to investigate the effects of stocking density on performance, meat quality and tibia development in Pekin ducks reared on a plastic wire floor. A total of 372 healthy, 21-day-old, male ducks with similar body weight (BW) were randomly allotted to stocking densities of five (low), eight (medium) and 11 (high) birds/m 2 . Each group had six replicates. Results showed that compared with the low density group, medium and high stocking density caused a decrease in final BW at 42 days old, and in average daily gain, European performance index (p study, the stocking density of male Pekin ducks should be adjusted between five and eight birds/m 2 . © 2018 Japanese Society of Animal Science.

  6. Effect of Gamma Radiation to the Content of Nutrition Duck Egg Environment Sample

    International Nuclear Information System (INIS)

    Sutjipto; Yohannes Sardjono

    2007-01-01

    The effect of gamma radiation dose of 0.7 kGy to the content of nutrition duck egg environment sample of Turi area, Bantul Yogyakarta has been studied. This research is conducted to determine the effect of gamma radiation 0.7 kGy to the nutrition duck egg which stored during 21 days. The grouped of some fresh duck egg sample to become 2 group. First group with 0 kGy (non irradiation) and the second group with 0.7 kGy dose. The irradiation sample was conducted at Kartini reactor Beamport. After the desired dose reached, the duck egg was lifted. Both irradiated and non irradiated duck egg then stored during 21 days. The research design used is Complete Block Random Device (RABL) with pattern factorial and restating as block. First factor : Dose of Irradiation (D) : D 1 = 0 kGy (non irradiation) and D 2 = 0.7 kGy. Second factors : stored time (P) : P 1 = 0 and day of P 2 = 21 days. The analysis of water content, total protein, dissolve protein, ash and fat was carried out. The research result shows that the gamma irradiation have no significant effect to the water content, total protein, dissolve protein, ash and fat both in white and also duck egg yolk for day of 0 (P> 0.05). For storage during 21 days, gamma radiation have significant effect to the water content, total protein, dissolve protein both in white and also duck egg yolk (P 0.05), because the irradiation process do not influence the availability of mineral in egg yolk and also have no significant effect to fat content (P> 0.05), because at the protein have compound which able to kill bacterium, so-called with lysozyme, besides high protein alkalinity which do not advantage growth of bacterium, so that during storage do not happened protein lipolysis by enzyme of lipase yielded by microbe. The effect of gamma radiation to the duck egg which stored during 21 days shows that the water content at white duck egg rising to 1.02 % wb, the protein total decreasing to 0.99 % db, the dissolve protein decreasing to 0

  7. Short beak and dwarfism syndrome of mule duck is caused by a distinct lineage of goose parvovirus.

    Science.gov (United States)

    Palya, Vilmos; Zolnai, Anna; Benyeda, Zsófia; Kovács, Edit; Kardi, Veronika; Mató, Tamás

    2009-04-01

    From the early 1970s to the present, numerous cases of short beak and dwarfism syndrome (SBDS) have been reported in mule ducks from France. The animals showed strong growth retardation with smaller beak and tarsus. It was suggested that the syndrome was caused by goose parvovirus on the basis of serological investigation, but the causative agent has not been isolated and the disease has not so far been reproduced by experimental infection. The aim of the present study was to characterize the virus strains isolated from field cases of SBDS, and to reproduce the disease experimentally. Phylogenetic analysis proved that the parvovirus isolates obtained from SBDS of mule duck belonged to a distinct lineage of goose parvovirus-related group of waterfowl parvoviruses. The authors carried out experimental infections of 1-day-old, 2-week-old and 3-week-old mule ducks by the oral route with three different parvovirus strains: strain D17/99 of goose parvovirus from Derzsy's disease, strain FM of Muscovy duck parvovirus from the parvovirus disease of Muscovy ducks, and strain D176/02 isolated from SBDS of mule duck. The symptoms of SBDS of the mule duck could only be reproduced with the mule duck isolate (strain D176/02) following 1-day-old inoculation. Infection with a genetically different strain of goose parvovirus isolated from classical Derzsy's disease (D17/99) or with the Muscovy duck parvovirus strain (FM) did not cause any clinical symptoms or pathological lesions in mule ducks.

  8. Ducks and passerines nesting in northern mixed-grass prairie treated with fire

    Science.gov (United States)

    Grant, Todd A.; Shaffer, Terry L.; Madden, Elizabeth M.; Berkey, Gordon B.

    2011-01-01

    Prescribed fire is an important, ecology-driven tool for restoration of grassland systems. However, prescribed fire remains controversial for some grassland managers because of reported reductions in bird use of recently burned grasslands. Few studies have evaluated effects of fire on grassland bird populations in the northern mixed-grass prairie region. Fewer studies yet have examined the influence of fire on nest density or survival. In our review, we found no studies that simultaneously examined effects of fire on duck and passerine nesting. During 1998—2003, we examined effects of prescribed fire on the density of upland-nesting ducks and passerines nesting in north-central North Dakota, USA. Apparent nest densities of gadwall (Anas strepera), mallard (A. platyrhynchos), and all duck species combined, were influenced by fire history of study units, although the degree of influence was not compelling. Fire history was not related to nest densities of blue-winged teal (A. discors), northern shoveler (A. clypeata), or northern pintail (A. acuta); however, apparent nest densities in relation to the number of postfire growing seasons exhibited a strikingly similar pattern among all duck species. When compared to ducks, fire history strongly influenced apparent nest densities of clay-colored sparrow (Spizella pallida), Savannah sparrow (Passerculus sandwichensis), and bobolink (Dolichonyx oryzivorus). For most species examined, apparent nest densities were lowest in recently burned units, increased during the second postfire growing season, and stabilized or, in some cases, decreased thereafter. Prescribed fire is critical for restoring the ecology of northern mixed-grass prairies and our findings indicate that reductions in nest densities are limited mostly to the first growing season after fire. Our results support the premise that upland-nesting ducks and several grassland passerine species are adapted to periodic fires occurring at a frequency similar to that

  9. Effect of cooking methods on the formation of heterocyclic aromatic amines in chicken and duck breast.

    Science.gov (United States)

    Liao, G Z; Wang, G Y; Xu, X L; Zhou, G H

    2010-05-01

    Heterocyclic aromatic amines (HAAs), potent mutagens/carcinogens, are pyrolysis formed during the cooking of meat and fish. In the present study, the effects of various cooking methods, pan-frying, deep-frying, charcoal grilling and roasting on the formation of HAAs in chicken breast and duck breast were studied. The various HAAs formed during cooking were isolated by solid-phase extraction and analyzed by high-performance liquid chromatography (HPLC). Results showed that chicken breast cooked by charcoal grilling contained the highest content of total HAAs, as high as 112 ng/g, followed by pan-fried duck breast (53.3 ng/g), charcoal grilled duck breast (32 ng/g), pan-fried chicken breast (27.4 ng/g), deep-fried chicken breast (21.3 ng/g), deep-fried duck breast (14 ng/g), roasted duck breast (7 ng/g) and roasted chicken breast (4 ng/g). For individual HAA, the most abundant HAA was 9H-pyrido-[4,3-b]indole (Norharman), which was detected in charcoal grilled chicken breast at content as high as 32.2 ng/g, followed by 1-methyl-9H-pyrido[4,3-b] indole (Harman) and 2-amino-1-methyl-6-phenylimidazo[4,5-f]pyridine(PhIP) at 32 and 31.1 ng/g in charcoal grilled chicken breast, respectively. The content of PhIP in pan-fried duck and chicken breast were 22 and 18.3 ng/g, respectively. Generally, the type and content of HAAs in cooked poultry meat varies with cooking method and cooking conditions. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  10. Anemia and mechanism of erythrocyte destruction in ducks with acute Leucocytozoon infections

    Science.gov (United States)

    Kocan, R.M.

    1968-01-01

    In the anemia which accompanies infection by Leucocytozoon simondi in Pekin ducks there was a far greater loss of erythrocytes than could be accounted for as a result of direct physical rupture by the parasite. Erythrocyte loss began at the same time the 1st parasites appeared in the blood and was severest just prior to maximum parasitemia. Blood replacement and parasite loss occurred simultaneously. Examination of the spleen and bone marrow revealed that erythrophagocytosis was not the cause of anemia as reported for infections of Plasmodium, Babesia and Anaplasma. An anti-erythrocyte (A-E) factor was found in the serum of acutely infected ducks which agglutinated and hemolyzed normal untreated duck erythrocytes as well as infected cells. This A-E factor appeared when the 1st red cell loss was detected and reached its maximum titer just prior to the greatest red cell loss. Titers of the A-E factor were determined using normal uninfected erythrocytes at temperatures between 4 and 42 C. Cells agglutinated below 25 C and hemolyzed at 37 and 42 C. These results indicated that the A-E factor could be responsible for loss of cells other than those which were infected and could thus produce an excess loss of red cells. Attempts to implicate the A-E factor as an autoantibody were all negative. The A-E factor was present in the gamma fraction of acute serum but no anamnestic response could be detected when recovered ducks were reinfected. Anemia was never as severe in reinfections as in primary infections. The A-E factor also never reached as high a titer and was removed from the circulation very rapidly in reinfected ducks. It is concluded that red cell loss in ducks with acute Leucocytozoon disease results from intravascular hemolysis rather than erythrophagocytosis. The A-E factor responsible for hemolysis is more likely a parasite product rather than autoantibody.

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