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Sample records for ross river glycoprotein-pseudotyped

  1. Climate variability and Ross River virus transmission.

    PubMed

    Tong, S; Bi, P; Donald, K; McMichael, A J

    2002-08-01

    (1) To examine the feasibility to link climate data with monthly incidence of Ross River virus (RRv). (2) To assess the impact of climate variability on the RRv transmission. An ecological time series analysis was performed on the data collected between 1985 to 1996 in Queensland, Australia. Information on the notified RRv cases was obtained from the Queensland Department of Health. Climate and population data were supplied by the Australian Bureau of Meteorology and the Australian Bureau of Statistics, respectively. Spearman's rank correlation analyses were performed to examine the relation between climate variability and the monthly incidence of notified RRv infections. The autoregressive integrated moving average (ARIMA) model was used to perform a time series analysis. As maximum and minimum temperatures were highly correlated with each other (r(s)=0.75), two separate models were developed. For the eight major cities in Queensland, the climate-RRv correlation coefficients were in the range of 0.12 to 0.52 for maximum and minimum temperatures, -0.10 to 0.46 for rainfall, and 0.11 to 0.52 for relative humidity and high tide. For the whole State, rainfall (partial regression coefficient: 0.017 (95% confidence intervals 0.009 to 0.025) in Model I and 0.018 (0.010 to 0.026) in Model II), and high tidal level (0.030 (0.006 to 0.054) in Model I and 0.029 (0.005 to 0.053) in Model II) seemed to have played significant parts in the transmission of RRv in Queensland. Maximum temperature was also marginally significantly associated with the incidence of RRv infection. Rainfall, temperature, and tidal levels may be important environmental determinants in the transmission cycles of RRv disease.

  2. Epidemic polyarthritis (Ross River) virus infection in the Cook Islands.

    PubMed

    Rosen, L; Gubler, D J; Bennett, P H

    1981-11-01

    An epidemic of Ross River virus infection occurred in the Cook Islands early in 1980 and affected the majority of the inhabitants of Rarotonga, the most populated island in the group. This represents the easternmost extension of the virus which, until 1979, was believed limited to Australia, New Guinea, and the Solomon Islands. The clinical manifestations of Ross River disease, predominantly polyarthritis, did not differ significantly from those observed previously in Australia. However, unlike the experience in Australia, where Ross River virus has never been isolated from a patient with polyarthritis, the agent was recovered from the serum of one-half of approximately 100 such patients with serologically proven infections. It is not known if this latter observation is the result of a change in the virus, the different virus isolation technique employed, or other factors. It was found that the incubation period of the disease could be as short as 3 days--much less than previously suspected. Ross River virus was isolated from six pools of Aedes polynesiensis mosquitoes collected in nature and it appeared that this species was the most probable vector on Rarotonga. In view of the widespread distribution of Ae. polynesiensis on islands, in the eastern Pacific it would not be surprising if Ross River virus occurs in other previously unaffected areas in the future.

  3. Risks for Ross River virus disease in tropical Australia.

    PubMed

    Harley, David; Ritchie, Scott; Bain, Chris; Sleigh, Adrian C

    2005-06-01

    There are no analytical studies of individual risks for Ross River virus (RRV) disease. Therefore, we set out to determine individual risk and protective factors for RRV disease in a high incidence area and to assess the utility of the case-control design applied for this purpose to an arbovirus disease. We used a prospective matched case-control study of new community cases of RRV disease in the local government areas of Cairns, Mareeba, Douglas, and Atherton, in tropical Queensland, from January 1 to May 31, 1998. Protective measures against mosquitoes reduced the risk for disease. Mosquito coils, repellents, and citronella candles each decreased risk by at least 2-fold, with a dose-response for the number of protective measures used. Light-coloured clothing decreased risk 3-fold. Camping increased the risk 8-fold. These risks were substantial and statistically significant, and provide a basis for educational programs on individual protection against RRV disease in Australia. Our study demonstrates the utility of the case-control method for investigating arbovirus risks. Such a risk analysis has not been done before for RRV infection, and is infrequently reported for other arbovirus infections.

  4. Increased Proinflammatory Cytokine Levels in Prolonged Arthralgia in Ross River Virus Infection

    PubMed Central

    Pérez-Girón, José Vicente; Gómez-Medina, Sergio; Günther, Stephan; Muñoz-Fontela, César; Schmidt-Chanasit, Jonas

    2017-01-01

    Ross River virus, a mosquitoborne alphavirus, causes epidemic polyarthritis in Australia and the Pacific region. We analyzed serum cytokine, chemokine, and growth factor levels in travelers returning to Germany from Australia. Serum samples showed elevated concentrations in the acute phase of the illness and, more pronounced, in the long-lasting convalescent phase. PMID:28322700

  5. The molecular and cellular aspects of arthritis due to alphavirus infections: lesson learned from Ross River virus.

    PubMed

    Rulli, Nestor E; Melton, Julian; Wilmes, Anja; Ewart, Gary; Mahalingam, Suresh

    2007-04-01

    Alphaviruses such as the Sindbis-group viruses, Scandinavian Ockelbo virus, the African Asian chikungunya virus, the African O'nyong-nyong virus, the South American Mayaro virus, and the Australasian Barmah Forest and Ross River viruses, are commonly associated with outbreaks of acute and persistent arthritis and arthralgia in humans. The mechanisms by which these viruses cause arthritis/arthralgia are poorly understood. This chapter summarizes our current understanding of viral arthritides using our newly developed mouse model of Ross River virus-induced joint and muscle inflammation.

  6. Evidence of vertical transmission of Ross River and Sindbis viruses (Togaviridae: Alphavirus) by mosquitoes (Diptera: Culicidae) in southeastern Australia.

    PubMed

    Dhileepan, K; Azuolas, J K; Gibson, C A

    1996-01-01

    Ross River and Sindbis viruses were isolated from Aedes camptorhynchus adults reared from immatures collected from a salt marsh in coastal Victoria, indicating the existence of field vertical transmission. These first isolations of an arbovirus from adult mosquitoes reared from field-collected immatures in Australia indicates one mechanism for arbovirus maintenance in temperate regions.

  7. Heparin binding sites on Ross River virus revealed by electron cryo-microscopy

    SciTech Connect

    Zhang Wei; Heil, Marintha; Kuhn, Richard J.; Baker, Timothy S. . E-mail: tsb@chem.ucsd.edu

    2005-02-20

    Cell surface glycosaminoglycans play important roles in cell adhesion and viral entry. Laboratory strains of two alphaviruses, Sindbis and Semliki Forest virus, have been shown to utilize heparan sulfate as an attachment receptor, whereas Ross River virus (RRV) does not significantly interact with it. However, a single amino acid substitution at residue 218 in the RRV E2 glycoprotein adapts the virus to heparan sulfate binding and expands the host range of the virus into chicken embryo fibroblasts. Structures of the RRV mutant, E2 N218R, and its complex with heparin were determined through the use of electron cryo-microscopy and image reconstruction methods. Heparin was found to bind at the distal end of the RRV spikes, in a region of the E2 glycoprotein that has been previously implicated in cell-receptor recognition and antibody binding.

  8. Epidemiologic patterns of Ross River virus disease in Queensland, Australia, 2001-2011.

    PubMed

    Yu, Weiwei; Mengersen, Kerrie; Dale, Pat; Mackenzie, John S; Toloo, Ghasem Sam; Wang, Xiaoyu; Tong, Shilu

    2014-07-01

    Ross River virus (RRV) infection is a debilitating disease that has a significant impact on population health, economic productivity, and tourism in Australia. This study examined epidemiologic patterns of RRV disease in Queensland, Australia, during January 2001-December 2011 at a statistical local area level. Spatio-temporal analyses were used to identify the patterns of the disease distribution over time stratified by age, sex, and space. The results show that the mean annual incidence was 54 per 100,000 persons, with a male:female ratio of 1:1.1. Two space-time clusters were identified: the areas adjacent to Townsville, on the eastern coast of Queensland, and the southeast areas. Thus, although public health intervention should be considered across all areas in which RRV occurs, it should specifically focus on high-risk regions, particularly during summer and autumn to reduce the social and economic impacts of RRV infection. © The American Society of Tropical Medicine and Hygiene.

  9. Environmental drivers of Ross River virus in southeastern Tasmania, Australia: towards strengthening public health interventions.

    PubMed

    Werner, A K; Goater, S; Carver, S; Robertson, G; Allen, G R; Weinstein, P

    2012-02-01

    In Australia, Ross River virus (RRV) is predominantly identified and managed through passive health surveillance. Here, the proactive use of environmental datasets to improve community-scale public health interventions in southeastern Tasmania is explored. Known environmental drivers (temperature, rainfall, tide) of the RRV vector Aedes camptorhynchus are analysed against cumulative case records for five adjacent local government areas (LGAs) from 1993 to 2009. Allowing for a 0- to 3-month lag period, temperature was the most significant driver of RRV cases at 1-month lag, contributing to a 23·2% increase in cases above the long-term case average. The potential for RRV to become an emerging public health issue in Tasmania due to projected climate changes is discussed. Moreover, practical outputs from this research are proposed including the development of an early warning system for local councils to implement preventative measures, such as public outreach and mosquito spray programmes.

  10. Epidemiologic Patterns of Ross River Virus Disease in Queensland, Australia, 2001–2011

    PubMed Central

    Yu, Weiwei; Mengersen, Kerrie; Dale, Pat; Mackenzie, John S.; Toloo, Ghasem (Sam); Wang, Xiaoyu; Tong, Shilu

    2014-01-01

    Ross River virus (RRV) infection is a debilitating disease that has a significant impact on population health, economic productivity, and tourism in Australia. This study examined epidemiologic patterns of RRV disease in Queensland, Australia, during January 2001–December 2011 at a statistical local area level. Spatio-temporal analyses were used to identify the patterns of the disease distribution over time stratified by age, sex, and space. The results show that the mean annual incidence was 54 per 100,000 persons, with a male:female ratio of 1:1.1. Two space-time clusters were identified: the areas adjacent to Townsville, on the eastern coast of Queensland, and the southeast areas. Thus, although public health intervention should be considered across all areas in which RRV occurs, it should specifically focus on high-risk regions, particularly during summer and autumn to reduce the social and economic impacts of RRV infection. PMID:24799374

  11. Climate variability and Ross River virus infections in Riverland, South Australia, 1992-2004.

    PubMed

    Bi, P; Hiller, J E; Cameron, A S; Zhang, Y; Givney, R

    2009-10-01

    Ross River virus (RRV) infection is the most common notifiable vector-borne disease in Australia, with around 6000 cases annually. This study aimed to examine the relationship between climate variability and notified RRV infections in the Riverland region of South Australia in order to set up an early warning system for the disease in temperate-climate regions. Notified data of RRV infections were collected by the South Australian Department of Health. Climatic variables and monthly river flow were provided by the Australian Bureau of Meteorology and South Australian Department of Water, Land and Biodiversity Conservation over the period 1992-2004. Spearman correlation and time-series-adjusted Poisson regression analysis were performed. The results indicate that increases in monthly mean minimum and maximum temperatures, monthly total rainfall, monthly mean Southern Oscillation Index and monthly flow in the Murray River increase the likelihood, but an increase in monthly mean relative humidity decreases the likelihood, of disease transmission in the region, with different time-lag effects. This study demonstrates that a useful early warning system can be developed for local regions based on the statistical analysis of readily available climate data. These early warning systems can be utilized by local public health authorities to develop disease prevention and control activities.

  12. Epidote Eclogites From Ross River Area, Yukon, Canada, Indicate Very High Pressure Metamorphism

    NASA Astrophysics Data System (ADS)

    Ghent, E. D.; Erdmer, P.

    2009-05-01

    Eclogites occur as tectonic inclusions in metasedimentary rocks at several locations within Yukon Territory. In the Ross River area the eclogites contain omphacite-garnet-Ca-Na amphibole-epidote-rutile-quartz. Phengite, paragonite, and titanite are local additional phases. The matrix of omphacite and Ca-amphibole is fine-grained and strongly deformed. Using bulk X-ray fluorescence analyses we have calculated isochemical phase diagram P-T sections (P-T pseudosections). The chemical system used is SiO2-TiO2- Al2O3-FeO-MgO-CaO-Na2O-K2O-H2O. We have not modeled MnO and ferric iron because of the lack of activity-composition data for minerals other than garnet. The P-T boundary of lawsonite- out provides approximate lower P and T limits on the stability of epidote with garnet and omphacite. The results are: 480-520°C at 20 kbar, near the lawsonite-eclogite/epidote-eclogite boundary at ˜ 500°C and 23 kbar. Garnet analyses indicate compositional zoning with Mn-rich cores. Intersections of the calculated grossular and pyrope isopleths (with observed compositions) provide estimates of P and T at the time of crystallization of garnet cores. The results range from 475-493°C and 19.7-23.5 kbar. Temperature estimates using the Zr in rutile geothermometer yield a T range of 521-557°C at 20 kbar. A metasedimentary host rock yielded three matrix results with 560 ± 54°C. These last results lead us to suggest that the host rocks experienced a similar T history to the eclogite inclusions. These eclogites were formed by subduction-related metamorphism, but did not involve continental collision. Ultrahigh pressures (coesite stability field) are usually associated with continental collision. The implied tectonic uplift of Ross River eclogite is greater than previously thought.

  13. Climate variation and incidence of Ross river virus in Cairns, Australia: a time-series analysis.

    PubMed

    Tong, S; Hu, W

    2001-12-01

    In this study we assessed the impact of climate variability on the Ross River virus (RRv) transmission and validated an epidemic-forecasting model in Cairns, Australia. Data on the RRv cases recorded between 1985 and 1996 were obtained from the Queensland Department of Health. Climate and population data were supplied by the Australian Bureau of Meteorology and the Australian Bureau of Statistics, respectively. The cross-correlation function (CCF) showed that maximum temperature in the current month and rainfall and relative humidity at a lag of 2 months were positively and significantly associated with the monthly incidence of RRv, whereas relative humidity at a lag of 5 months was inversely associated with the RRv transmission. We developed autoregressive integrated moving average (ARIMA) models on the data collected between 1985 to 1994, and then validated the models using the data collected between 1995 and 1996. The results show that the relative humidity at a lag of 5 months (p < 0.001) and the rainfall at a lag of 2 months (p < 0.05) appeared to play significant roles in the transmission of RRv disease in Cairns. Furthermore, the regressive forecast curves were consistent with the pattern of actual values.

  14. Ross River Virus Transmission, Infection, and Disease: a Cross-Disciplinary Review

    PubMed Central

    Harley, David; Sleigh, Adrian; Ritchie, Scott

    2001-01-01

    Ross River virus (RRV) is a fascinating, important arbovirus that is endemic and enzootic in Australia and Papua New Guinea and was epidemic in the South Pacific in 1979 and 1980. Infection with RRV may cause disease in humans, typically presenting as peripheral polyarthralgia or arthritis, sometimes with fever and rash. RRV disease notifications in Australia average 5,000 per year. The first well-described outbreak occurred in 1928. During World War II there were more outbreaks, and the name epidemic polyarthritis was applied. During a 1956 outbreak, epidemic polyarthritis was linked serologically to a group A arbovirus (Alphavirus). The virus was subsequently isolated from Aedes vigilax mosquitoes in 1963 and then from epidemic polyarthritis patients. We review the literature on the evolutionary biology of RRV, immune response to infection, pathogenesis, serologic diagnosis, disease manifestations, the extraordinary variety of vertebrate hosts, mosquito vectors, and transmission cycles, antibody prevalence, epidemiology of asymptomatic and symptomatic human infection, infection risks, and public health impact. RRV arthritis is due to joint infection, and treatment is currently based on empirical anti-inflammatory regimens. Further research on pathogenesis may improve understanding of the natural history of this disease and lead to new treatment strategies. The burden of morbidity is considerable, and the virus could spread to other countries. To justify and design preventive programs, we need accurate data on economic costs and better understanding of transmission and behavioral and environmental risks. PMID:11585790

  15. Development of a predictive model for ross river virus disease in Brisbane, Australia.

    PubMed

    Hu, Wenbiao; Nicholls, Neville; Lindsay, Mike; Dale, Pat; McMichael, Anthony J; Mackenzie, John S; Tong, Shilu

    2004-08-01

    This paper describes the development of an empirical model to forecast epidemics of Ross River virus (RRV) disease using the multivariate seasonal auto-regressive integrated moving average (SARIMA) technique in Brisbane, Australia. We obtained computerized data on notified RRV disease cases, climate, high tide, and population sizes in Brisbane for the period 1985-2001 from the Queensland Department of Health, the Australian Bureau of Meteorology, the Queensland Department of Transport, and Australian Bureau of Statistics, respectively. The SARIMA model was developed and validated by dividing the data file into two data sets: the data between January 1985 and December 2000 were used to construct a model, and those between January and December 2001 to validate it. The SARIMA models show that monthly precipitation (beta = 0.004, P = 0.031) was significantly associated with RRV transmission. However, there was no significant association between other climate variables (e.g., temperature, relative humidity, and high tides) and RRV transmission. The predictive values in the model were generally consistent with actual values (root mean square percentage error = 0.94%). Therefore, this model may have applications as a decision supportive tool in disease control and risk-management planning programs.

  16. Regional Comparison of Mosquito Bloodmeals in South Australia: Implications for Ross River Virus Ecology.

    PubMed

    Flies, Emily J; Flies, Andrew S; Fricker, Stephen R; Weinstein, Philip; Williams, Craig R

    2016-07-01

    Ross River virus (RRV) is responsible for the most notifications of human arboviral infection in Australia. Seroprevalence and experimental infection studies have implicated macropods (e.g., kangaroos) as the major reservoir hosts. However, transmission ecology varies spatially, and infections in urban areas have prompted the question of what animals serve as reservoirs in regions where macropods are scarce. In South Australia (SA), human infection rates for RRV vary greatly by region as do vector and reservoir abundance. We hypothesized that mosquito abundance and feeding patterns would vary among ecoregions of SA and could help explain divergent human case rates. To test our hypothesis, we amplified and sequenced a 457 base pair region of the cytochrome B segment of mitochondrial DNA from blood fed mosquitoes collected in three main ecoregions of SA and identified sequences using a BLAST search in NCBI. Domestic livestock made up the vast majority of bloodmeals from the region with the highest human infection rate. Livestock are generally not considered to be important reservoir hosts for RRV, but our results suggest they may have a role in transmission ecology in some places. Surprisingly, none of the 199 bloodmeal samples were identified as macropod in origin. In the context of these findings, we consider the possible RRV vectors and reservoir hosts in these regions and propose that diverse spatial and temporal transmission ecologies occur in SA, depending on vector and reservoir availability. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Recreational water quality control in Mississippi, USA: bacteriological assessment in the Pearl River and Ross Barnett reservoir.

    PubMed

    Kishinhi, Stephen; Tchounwou, Paul B; Farah, Ibrahim O; Chigbu, Paulinus

    2006-01-01

    We assessed the bacteriological water quality in the Pearl River and Ross Barnett reservoir, a major source of public raw water for the city of Jackson, Mississippi, USA and an important site for recreational activities for local residents and visitors. Infectious diseases caused by pathogenic bacteria are the most common and widespread health risks associated with such water contact activities as bathing, canoeing, and swimming in recreational waters. Water samples collected twice monthly from April 2004 to April 2005 from five different sites of the Pearl river/Ross Barnett reservoir were tested for heterotrophic bacteria, total coliforms, fecal coliforms, and enterococci using membrane filtration technique. Physicochemical parameters (temperature, pH, turbidity, dissolved oxygen, conductivity) were also analyzed using standard methods. The respective mean concentrations of bacteria in water samples were 8.9 x 10(4) +/- 7.4 x 10(4) colony forming units (CFU) 100 mL(-1), 3.0 x 10(3) +/- 4.1 x 10(3) CFU 100 mL(-1), 2.3 x 10(2) +/- 5.4 x 10(2) CFU 100 mL(-1), and 2.3 x 10(2) +/- 4.8 x 10(2) CFU 100 mL(-1) for heterotrophic bacteria, total coliforms, enterococci, and fecal coliforms. The mean values of the physical and chemical parameters were at acceptable levels. Bacterial densities, however, significantly exceeded federal/state guidelines, raising public health concerns. Hence, control strategies should be developed and implemented to prevent further bacterial contamination of Pearl River-Ross Barnett reservoir water resource system.

  18. Seroprevalence of Antibodies to Ross River and Barmah Forest Viruses: Possible Implications for Blood Transfusion Safety After Extreme Weather Events.

    PubMed

    Faddy, Helen; Dunford, Melanie; Seed, Clive; Olds, Andrew; Harley, David; Dean, Melinda; Racloz, Vanessa; McCarthy, Suzi; Smith, David; Flower, Robert

    2015-06-01

    Climate change is predicted to increase the transmission of many vector-borne pathogens, representing an increasing threat to a safe blood supply. In early 2011, Australia experienced catastrophic rainfall and flooding, coupled with increased arbovirus transmission. We used Ross River (RRV) and Barmah Forest (BFV) viruses as test cases to investigate the potential risk posed to Australia's blood supply after this period of increased rainfall . We estimated the risk of collecting an infected donation as one in 2,500-58,000 for RRV and one in 2,000-28,000 for BFV. Climate change may incrementally increase the arbovirus threat to blood safety.

  19. Antibodies to the Ross River virus in captive marsupials in urban areas of eastern New South Wales, Australia.

    PubMed

    Old, Julie M; Deane, Elizabeth M

    2005-07-01

    Serum samples collected from 224 tammar wallabies (Macropus eugenii) in two captive populations in urban areas in eastern New South Wales Australia, between December 1999 and May 2004, were tested for antibodies to Ross River virus (RRV). In one population in northwest Sydney, 21 animals (11%) tested positive, and in another population in Newcastle, New South Wales, thirteen (33%) of the animals were positive. Antibodies were detected in four of 11 wallaroos (Macropus robustus) (36%) but not in parma wallabies (Macropus parma) (n=5), koalas (Phascolarctos cinereus) (n=12) and southern hairy-nosed wombats (Lasiorhinus latifrons) (n=2) from the Sydney area. These data support the possible role of marsupials as urban amplifying hosts for RRV.

  20. Exploratory spatial analysis of social and environmental factors associated with the incidence of Ross River virus in Brisbane, Australia.

    PubMed

    Hu, Wenbiao; Tong, Shilu; Mengersen, Kerrie; Oldenburg, Brian

    2007-05-01

    We used geographic information systems and a spatial analysis approach to explore the pattern of Ross River virus (RRV) incidence in Brisbane, Australia. Climate, vegetation and socioeconomic data in 2001 were obtained from the Australian Bureau of Meteorology, the Brisbane City Council and the Australian Bureau of Statistics, respectively. Information on the RRV cases was obtained from the Queensland Department of Health. Spatial and multiple negative binomial regression models were used to identify the socioeconomic and environmental determinants of RRV transmission. The results show that RRV activity was primarily concentrated in the northeastern, northwestern, and southeastern regions in Brisbane. Multiple negative binomial regression models showed that the spatial pattern of RRV disease in Brisbane seemed to be determined by a combination of local ecologic, socioeconomic, and environmental factors.

  1. Ross River Virus Disease Activity Associated With Naturally Occurring Nontidal Flood Events in Australia: A Systematic Review.

    PubMed

    Tall, Julie A; Gatton, Michelle L; Tong, Shilu

    2014-11-01

    Ross River virus (RRV) disease is the most common and widespread mosquito-borne disease in Australia, resulting in considerable health and economic cost to communities. While naturally occurring nontidal flood events may enhance mosquito abundance, little is known about the impact of such events on RRV transmission. This article critically reviews the existing evidence for an association between naturally occurring nontidal flood events and RRV transmission. A systematic literature search was conducted on RRV transmission related to flooding and inundation from rain and riverine overflow. Overall, the evidence to support a positive association between flooding and RRV outbreaks is largely circumstantial, with the literature mostly reporting only coincidental occurrence between the two. However, for the Murray River, river flow and height (surrogates of flooding) were positively and significantly associated with RRV transmission. The association between nontidal flooding and RRV transmission has not been studied comprehensively. More frequent flood events arising from climate change may result in increased outbreaks of RRV disease. Understanding the link between flood events and RRV transmission is necessary if resources for mosquito spraying and public health warnings are to be used more effectively and efficiently.

  2. Occurrence of Ross River virus and Barmah Forest virus in mosquitoes at Shoalwater Bay military training area, Queensland, Australia.

    PubMed

    Frances, S P; Cooper, R D; Rowcliffe, K L; Chen, N; Cheng, Q

    2004-01-01

    Shoalwater Bay military training area (SWBTA), 2,713 km2 of land located 50-80 km north of Rockhampton, Queensland, Australia, is used by Australian and allied forces for training purposes. Between March 1998 and February 2000, monthly collections of mosquitoes at 15 sites were conducted using carbon dioxide-baited traps to study the seasonal occurrence of mosquitoes and Ross River virus (RRV) and Barmah Forest virus (BFV) in mosquitoes. A total of 72,616 mosquitoes, comprising 3,897 pools were collected, and 2,428 pools were tested using a reverse transcriptase-polymerase chain reaction. A total of 15 pools of mosquitoes were positive for virus, 10 RRV and five BFV. Blood meals from an additional 763 mosquitoes were tested by a gel diffusion assay, and the majority (96%) of those identified were from kangaroo, which was the most common mammal in the study area. The results indicate that Culex annulirostris Skuse and Ochlerotatus vigilax (Skuse) are the main vectors of RRV at SWBTA.

  3. Critical role for macrophage migration inhibitory factor (MIF) in Ross River virus-induced arthritis and myositis.

    PubMed

    Herrero, Lara J; Nelson, Michelle; Srikiatkhachorn, Anon; Gu, Ran; Anantapreecha, Surapee; Fingerle-Rowson, Günter; Bucala, Richard; Morand, Eric; Santos, Leilani L; Mahalingam, Suresh

    2011-07-19

    Arthrogenic alphaviruses, such as Ross River virus (RRV), chikungunya, Sindbis, mayaro and o'nyong-nyong viruses circulate endemically worldwide, frequently causing outbreaks of polyarthritis. The exact mechanisms of how alphaviruses induce polyarthritis remain ill defined, although macrophages are known to play a key role. Macrophage migration inhibitory factor (MIF) is an important cytokine involved in rheumatoid arthritis pathogenesis. Here, we characterize the role of MIF in alphavirus-induced arthritides using a mouse model of RRV-induced arthritis, which has many characteristics of RRV disease in humans. RRV-infected WT mice developed severe disease associated with up-regulated MIF expression in serum and tissues, which corresponded to severe inflammation and tissue damage. MIF-deficient (MIF(-/-)) mice developed mild disease accompanied by a reduction in inflammatory infiltrates and muscle destruction in the tissues, despite having viral titers similar to WT mice. In addition, reconstitution of MIF into MIF(-/-) mice exacerbated RRV disease and treatment of mice with MIF antagonist ameliorated disease in WT mice. Collectively, these findings suggest that MIF plays a critical role in determining the clinical severity of alphavirus-induced musculoskeletal disease and may provide a target for the development of antiviral pharmaceuticals. The prospect being that early treatment with MIF-blocking pharmaceuticals may curtail the debilitating arthritis associated with alphaviral infections.

  4. Projecting the impact of climate change on the transmission of Ross River virus: methodological challenges and research needs.

    PubMed

    Yu, W; Dale, P; Turner, L; Tong, S

    2014-10-01

    Ross River virus (RRV) is the most common vector-borne disease in Australia. It is vitally important to make appropriate projections on the future spread of RRV under various climate change scenarios because such information is essential for policy-makers to identify vulnerable communities and to better manage RRV epidemics. However, there are many methodological challenges in projecting the impact of climate change on the transmission of RRV disease. This study critically examined the methodological issues and proposed possible solutions. A literature search was conducted between January and October 2012, using the electronic databases Medline, Web of Science and PubMed. Nineteen relevant papers were identified. These studies demonstrate that key challenges for projecting future climate change on RRV disease include: (1) a complex ecology (e.g. many mosquito vectors, immunity, heterogeneous in both time and space); (2) unclear interactions between social and environmental factors; and (3) uncertainty in climate change modelling and socioeconomic development scenarios. Future risk assessments of climate change will ultimately need to better understand the ecology of RRV disease and to integrate climate change scenarios with local socioeconomic and environmental factors, in order to develop effective adaptation strategies to prevent or reduce RRV transmission.

  5. Osteoblasts from osteoarthritis patients show enhanced susceptibility to Ross River virus infection associated with delayed type I interferon responses.

    PubMed

    Chen, Weiqiang; Foo, Suan-Sin; Li, Rachel W; Smith, Paul N; Mahalingam, Suresh

    2014-11-19

    Arthritogenic alphaviruses such as Ross River virus (RRV) and chikungunya virus (CHIKV) have caused widespread outbreaks of chronic polyarthritis. The inflammatory responses in alphavirus-induced arthritis and osteoarthritis (OA) share many similar features, which suggests the possibility of exacerbated alphavirus-induced bone pathology in individuals with pre-existing OA. Here, we investigated the susceptibility of osteoblasts (OBs) from OA patients to RRV infection and dissected the immune mechanisms elicited from infection. Primary hOBs obtained from trabecular bone of healthy donors and OA patients were infected with RRV. Infectivity and viral replication were determined using flow cytometry and plaque assay, respectively. Real-time PCR was performed to determine expression kinetics of type I interferon (IFN)-related immune mediators and osteotropic factors. OA hOBs showed enhanced RRV infectivity and replication during infection, which was associated with delayed induction of IFN-β and RIG-I expression. Enhanced susceptibility of OA hOBs to RRV was associated with a more pronounced increase in RANKL/OPG ratio and expression of osteotropic factors (IL-6, IL-1β, TNF-α and CCL2) in comparison to RRV-infected healthy hOBs. Delayed activation of type I IFN-signalling pathway may have contributed to enhanced susceptibility to RRV infection in hOBs from OA patients. RRV-induced increases in RANKL/OPG ratio and expression of osteotropic factors that favour bone resorption, which may be exacerbated during osteoarthritis. This study provides the novel insight that osteoarthritis may be a risk factor for exacerbated arthritogenic alphaviral infection.

  6. Climate variability, social and environmental factors, and ross river virus transmission: research development and future research needs.

    PubMed

    Tong, Shilu; Dale, Pat; Nicholls, Neville; Mackenzie, John S; Wolff, Rodney; McMichael, Anthony J

    2008-12-01

    Arbovirus diseases have emerged as a global public health concern. However, the impact of climatic, social, and environmental variability on the transmission of arbovirus diseases remains to be determined. Our goal for this study was to provide an overview of research development and future research directions about the interrelationship between climate variability, social and environmental factors, and the transmission of Ross River virus (RRV), the most common and widespread arbovirus disease in Australia. We conducted a systematic literature search on climatic, social, and environmental factors and RRV disease. Potentially relevant studies were identified from a series of electronic searches. The body of evidence revealed that the transmission cycles of RRV disease appear to be sensitive to climate and tidal variability. Rainfall, temperature, and high tides were among major determinants of the transmission of RRV disease at the macro level. However, the nature and magnitude of the interrelationship between climate variability, mosquito density, and the transmission of RRV disease varied with geographic area and socioenvironmental condition. Projected anthropogenic global climatic change may result in an increase in RRV infections, and the key determinants of RRV transmission we have identified here may be useful in the development of an early warning system. The analysis indicates that there is a complex relationship between climate variability, social and environmental factors, and RRV transmission. Different strategies may be needed for the control and prevention of RRV disease at different levels. These research findings could be used as an additional tool to support decision making in disease control/surveillance and risk management.

  7. 2. ROSS POWERHOUSE: TRANSFORMER DECK, TAILRACE, AND BOATHOUSE AS SEEN ...

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

    2. ROSS POWERHOUSE: TRANSFORMER DECK, TAILRACE, AND BOATHOUSE AS SEEN FROM EAST END OF TRANSFORMER DECK, 1989. - Skagit Power Development, Ross Powerhouse, On Skagit River, 10.7 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  8. 5. ROSS POWERHOUSE: SAME CAMERA STATION AS ABOVE PHOTO BUT ...

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

    5. ROSS POWERHOUSE: SAME CAMERA STATION AS ABOVE PHOTO BUT LOOKING EAST. NOTE INFORMATION DISPLAY FOR TOURISTS AT FLOOR LEVEL, 1987. - Skagit Power Development, Ross Powerhouse, On Skagit River, 10.7 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  9. 20. ROSS POWERHOUSE: BUTTERFLY VALVE AS SEEN FROM INSIDE THE ...

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

    20. ROSS POWERHOUSE: BUTTERFLY VALVE AS SEEN FROM INSIDE THE SCROLL CASE, 1987. - Skagit Power Development, Ross Powerhouse, On Skagit River, 10.7 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  10. 18. ROSS POWERHOUSE: BUTTERFLY VALVE FROM BELOW AND SCROLL CASE ...

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

    18. ROSS POWERHOUSE: BUTTERFLY VALVE FROM BELOW AND SCROLL CASE DRAIN. TAG INDICATES THE SCROLL CASE DRAIN WAS OPEN, 1989. - Skagit Power Development, Ross Powerhouse, On Skagit River, 10.7 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  11. 12. ROSS POWERHOUSE: DETAIL OF GAUGES AND PUMPS IN UNIT ...

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

    12. ROSS POWERHOUSE: DETAIL OF GAUGES AND PUMPS IN UNIT 41 TURBINE PIT, 1989. - Skagit Power Development, Ross Powerhouse, On Skagit River, 10.7 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  12. Ross Sea

    Atmospheric Science Data Center

    2013-04-16

    article title:  Icebergs in the Ross Sea     View Larger Image Two large icebergs, designated B-15A and C-16, are captured in this Multi-angle Imaging ... the longitudinal quadrant in which it is first seen, and new icebergs sighted in that quadrant are sequentially numbered. B-15 divided from ...

  13. Different responses of Ross River virus to climate variability between coastline and inland cities in Queensland, Australia.

    PubMed

    Tong, S; Hu, W

    2002-11-01

    To examine the potential impact of climate variability on the transmission of Ross River virus (RRv) infection, and to assess the difference in the potential predictors of RRv incidence in coastline and inland regions, Queensland, Australia. Information on the RRv cases notified between 1985 to 1996 was obtained from the Queensland Department of Health. Climate and population data were supplied by the Australian Bureau of Meteorology and the Australia Bureau of Statistics, respectively. The function of cross correlations was used to compute a series of correlations between climate variables (rainfall, maximum temperature, minimum temperature, relative humidity, and high tide) and the monthly incidence of RRv disease over a range of time lags. Time series Poisson regression models were performed to adjust for the autocorrelations of the monthly incidences of RRv disease and the confounding effects of seasonality, the case notification time, and population sizes. The cross correlation function shows rainfall, maximum temperature, minimum temperature, and relative humidity at a lag of 1-2 months and high tide in the current month were significantly associated with the monthly incidence of RRv in the coastline region. Relative humidity and rainfall at a lag of two months was also significantly associated with the monthly incidence of RRv in the inland region. The results of Poisson regressive models show that the incidence of RRv disease was significantly associated with rainfall, maximum temperature, minimum temperature, relative humidity, and high tide in the coastline region, and with rainfall and relative humidity in the inland region. There was a significant interaction between climate variables and locality in RRv transmission. Climate variability may have played a significant role in the transmission of RRv. There appeared to be different responses of RRv to climate variability between coastline and inland cities in Queensland, Australia. Maximum temperature

  14. Proximity to mosquito breeding habitat and Ross River virus risk in the Peel region of Western Australia.

    PubMed

    Jardine, Andrew; Neville, Peter J; Lindsay, Michael D A

    2015-02-01

    It is intuitive that vector-borne disease exposure risk is related to proximity to sources of vector breeding, but this aspect rarely receives empirical testing. The population of Western Australia (WA) is increasing rapidly, with many new residential developments proposed in close proximity to mosquito breeding habitat. However, potential mosquito-borne disease risks for future residents are given little consideration by planning authorities. The Peel region is one of the fastest growing regions in WA and regularly experiences a large number of cases of the mosquito-borne Ross River virus (RRV) disease with epidemics occuring in the region every few years. A spatial analysis of RRV disease data in the Peel region was undertaken to determine the risk associated with proximity to a mosquito breeding habitat. Geographic Information Systems (GIS) software was used to create buffers between 1 and 6 km from the breeding habitat. The number of cases per 1000 dwellings in each buffer was calculated between 2002/03 to 2011/12 for years with >100 cases across all buffers (n=5) in addition to the cumulative rate over the entire period in each buffer. Residents living within 1 km of a mosquito breeding habitat had a significantly higher rate of RRV disease compared to the background rate across the Peel region in all individual years investigated. The cumulative data over the 10-year study period showed that residents in the 1- and 2-km buffers had a significantly higher rate, whereas those living between 3 and 6 km away did not. This study demonstrates an increased mosquito-borne disease risk associated with living in close proximity to a mosquito breeding habitat in a rapidly expanding region of WA and highlights the importance of considering mosquito-borne disease risks when planning authorities assess new residential development applications. Known mosquito breeding wetlands should be incorporated into land use planning scheme maps to ensure that they are accurately

  15. Proximity to Mosquito Breeding Habitat and Ross River Virus Risk in the Peel Region of Western Australia

    PubMed Central

    Neville, Peter J.; Lindsay, Michael D.A.

    2015-01-01

    Abstract It is intuitive that vector-borne disease exposure risk is related to proximity to sources of vector breeding, but this aspect rarely receives empirical testing. The population of Western Australia (WA) is increasing rapidly, with many new residential developments proposed in close proximity to mosquito breeding habitat. However, potential mosquito-borne disease risks for future residents are given little consideration by planning authorities. The Peel region is one of the fastest growing regions in WA and regularly experiences a large number of cases of the mosquito-borne Ross River virus (RRV) disease with epidemics occuring in the region every few years. A spatial analysis of RRV disease data in the Peel region was undertaken to determine the risk associated with proximity to a mosquito breeding habitat. Geographic Information Systems (GIS) software was used to create buffers between 1 and 6 km from the breeding habitat. The number of cases per 1000 dwellings in each buffer was calculated between 2002/03 to 2011/12 for years with >100 cases across all buffers (n=5) in addition to the cumulative rate over the entire period in each buffer. Residents living within 1 km of a mosquito breeding habitat had a significantly higher rate of RRV disease compared to the background rate across the Peel region in all individual years investigated. The cumulative data over the 10-year study period showed that residents in the 1- and 2-km buffers had a significantly higher rate, whereas those living between 3 and 6 km away did not. This study demonstrates an increased mosquito-borne disease risk associated with living in close proximity to a mosquito breeding habitat in a rapidly expanding region of WA and highlights the importance of considering mosquito-borne disease risks when planning authorities assess new residential development applications. Known mosquito breeding wetlands should be incorporated into land use planning scheme maps to ensure that they are

  16. Regulation of type I-interferon responses in the human epidermal melanocyte cell line SKMEL infected by the Ross River alphavirus.

    PubMed

    Assi, Mohamad; Thon-Hon, Vincent Gérard; Jaffar-Bandjee, Marie-Christine; Martinez, Audrey; Gasque, Philippe

    2015-12-01

    Melanocytes are melanin-producing cells and with emerging innate immune functions including the expression of antiviral interferon-type I cytokines. We herein ascertained the susceptibility of the human melanocytes to Ross River alphavirus (RRV) infection and analyzed the subsequent immune responses. We demonstrated for the first time that (1) SKMEL-28 melanocyte cell line was susceptible to RRV infection and displaying major cytopathic activities and (2) RRV interfered with the interferon-type I response by altering nuclear translocation of pSTAT1 and pSTAT2 in infected SKMEL-28. These results suggest that the human melanoma cell line SKMEL-28 is a valuable model to analyze the mechanisms involved in severe skin manifestations and melanocyte's immunity at the portal of entry of major infection by arboviruses.

  17. Ross River Virus Risk Associated with Dispersal of Aedes (Ochlerotatus) camptorhynchus (Thomson) from Breeding Habitat into Surrounding Residential Areas: Muddy Lakes, Western Australia

    PubMed Central

    Jardine, Andrew; Neville, Peter J.; Dent, Colin; Webster, Carla; Lindsay, Michael D. A.

    2014-01-01

    Rapid population growth in Western Australia has resulted in increased development of land for residential housing, and new developments are often proposed close to water because of intrinsic aesthetic values. However, this placement may place future residents at risk of mosquito-borne disease, of which Ross River virus (RRV) disease is the most common in Australia. Mosquito dispersal data were combined with a spatial analysis of human RRV cases to show that mosquitoes dispersed readily from larval habitat into surrounding low- and high-density residential areas and that residents living within 2 km of mosquito breeding habitat had a significantly higher rate of RRV disease. This finding highlights the importance of planning authorities in state and local governments to consider the implications of mosquito-borne disease risks when assessing residential development applications. PMID:24799370

  18. Experimental infection of Australian brushtail possums, Trichosurus vulpecula (Phalangeridae: Marsupialia), with Ross River and Barmah Forest viruses by use of a natural mosquito vector system.

    PubMed

    Boyd, A M; Hall, R A; Gemmell, R T; Kay, B H

    2001-12-01

    Brushtail possums, Trichosurus vulpecula Kerr, were experimentally infected with Ross River (RR) or Barmah Forest (BF) virus by Aedes vigilax (Skuse) mosquitoes. Eight of 10 animals exposed to RR virus developed neutralizing antibody, and 3 possums developed high viremia for < 48 hr after infection, sufficient to infect recipient mosquitoes. Two of 10 animals exposed to BF virus developed neutralizing antibody. Both infected possums maintained detectable neutralizing antibody to BF for at least 45 days after infection (log neutralization index > 2.0 at 45 days). Eight possums did not develop neutralizing antibody to BF despite exposure to infected mosquitoes. These results suggest that T. vulpecula may potentially act as a reservoir species for RR in urban areas. However, T. vulpecula infected with BF do not develop viremia sufficient to infect mosquitoes and are unlikely to be important hosts for BF.

  19. Geographic Information Systems used to describe the link between the risk of Ross River virus infection and proximity to the Leschenault estuary, WA.

    PubMed

    Vally, Hassan; Peel, Mark; Dowse, Gary K; Cameron, Scott; Codde, Jim P; Hanigan, Ivan; Lindsay, Michael D A

    2012-06-01

    To investigate the relationship between risk of Ross River virus (RRV) infection and proximity to mosquito-breeding habitat surrounding a tidal wetland ecosystem in south-west Australia. Geographic information systems (GIS) were used to spatially map cases of RRV disease in the Leschenault region between July 1995 and June 1996. Half kilometre buffer zones were constructed around the Leschenault Estuary and associated waterways; RRV disease case counts were calculated for each zone. Different relationships between RRV disease incidence and proximity to saltmarsh mosquito habitat were observed east of the Leschenault Estuary compared with an urban region to the south. Disease incidence showed a decreasing trend away from eastern margins of the Estuary, particularly for the first 2 km. In the urban region, RRV disease risk was low close to the Estuary, but increased further out and remained steady across the remainder of that region. The findings support an increased risk of contracting RRV disease for people residing close to eastern margins of the Leschenault Estuary. This study highlights how historical data combined with GIS can improve understanding of the epidemiology of RRV disease. This has a valuable role in assessing the risk of mosquito-borne disease for land-use planning. © 2012 The Authors. ANZJPH © 2012 Public Health Association of Australia.

  20. Does mosquito control have an effect on mosquito-borne disease? The case of Ross River virus disease and mosquito management in Queensland, Australia.

    PubMed

    Tomerini, Deanna M; Dale, Pat E; Sipe, Neil

    2011-03-01

    We examined the relationship between types of mosquito control programs and the mosquito-borne Ross River virus (RRV) disease in Queensland, Australia. Mosquito control information was collected through a survey of the responsible agencies (local governments), and RRV disease notification data were provided by the Queensland state health authority. The study developed a typology of mosquito control programs, based on the approaches used. Based on the analysis of data on RRV disease rates between mosquito control types within 4 climatic regions, each region had different combinations of mosquito control strategies in their programs; there were also general similarities in the relationship between program types and RRV rates between the regions. The long-term RRV disease rates were lower in areas where the mosquito control program included pre-emptive (rather than reactive) surveillance based on an extensive (rather than incomplete) knowledge of mosquito habitats, and where treatment of both saltwater and freshwater habitats (compared to only saltwater habitats, in coastal areas) occurred. The data indicate that mosquito control is an effective public health intervention to reduce mosquito-borne disease; hence, climate change adaptation strategies should ensure that adequate resources are available for effective vector control so as to manage the risk of mosquito-borne diseases.

  1. Impact of dryland salinity on population dynamics of vector mosquitoes (Diptera: Culicidae) of Ross River virus in inland areas of southwestern Western Australia.

    PubMed

    Jardine, A; Lindsay, M D A; Johansen, C A; Cook, A; Weinstein, P

    2008-11-01

    Clearing of native vegetation for agriculture since European settlement has left 1.047 million ha of southwestern Australia affected by a severe form of environmental degradation called dryland salinity, characterized by secondary soil salinization and waterlogging. This area may expand by a further 1.7-3.4 million ha if current trends continue. Detailed investigations of seasonal of adult and larval mosquito population dynamics were undertaken in the region to test the hypothesis that the development of dryland salinity and waterlogging in inland southwestern Australia has led to a succession of mosquito species and increased Ross River virus (family Togaviridae, genus Alphavirus, RRV) transmission risk. Aedes (Ochlerotatus) camptorhynchus (Thomson) made up >90% of adult mosquito collections in saline regions. Nonmetric multidimensional scaling and generalized estimating equations modeling demonstrated that it was strongly associated with increasing severity of dryland salinity. This article describes the first detailed investigation of the mosquito fauna of inland southwestern Australia, and it is the first description of the influence of secondary soil salinity on mosquito population dynamics. Despite the dominant presence of Ae. camptorhynchus, RRV disease incidence is not currently a significant population health priority in areas affected by dryland salinity. Potential limiting factors include local climatic impacts on the seasonal mosquito population dynamics, vertebrate host distribution and feeding behavior of Ae. camptorhynchus, and the scarce and uneven distribution of the human population in the region.

  2. Ross River virus infection surveillance in the Greater Perth Metropolitan area--has there been an increase in cases in the winter months?

    PubMed

    Selvey, Linda A; Donnelly, Jenny A; Lindsay, Michael D; PottumarthyBoddu, Sudha; D'Abrera, Victoria C; Smith, David W

    2014-06-30

    An increase in off-season (June to September) Ross River virus (RRV) notifications from the greater Perth metropolitan area was observed from 2006 to 2009. We investigated the increase to determine whether it is likely to have reflected a true increase in off-season cases. A single positive RRV IgM test result is sufficient for RRV notification but where follow-up testing was performed, the positive predictive value of an IgM test where IgG was negative was very low in the off-season and also in the season when using the only commercially available test kit. The increase in off-season notifications was not associated with an increase in off-season testing. Some Perth laboratories use more stringent notification criteria than the nationally agreed RRV case definition, and the geographical distribution of samples tested varies between laboratories. Our findings make a strong case to change the nationally agreed case definition for RRV to not accept a single IgM positive test result as laboratory definitive evidence where the IgG is negative. Our study also identified a range of challenges in interpreting changes in seasonal patterns and geographical distribution of RRV. Any such observed changes should be investigated through further data analysis and/or mosquito trapping and testing in order to assess validity.

  3. Difference in mosquito species (Diptera: Culicidae) and the transmission of Ross River virus between coastline and inland areas in Brisbane, Australia.

    PubMed

    Hu, W; Mengersen, K; Dale, P; Tong, S

    2010-02-01

    This study examined the distribution of major mosquito species and their roles in the transmission of Ross River virus (RRV) infection for coastline and inland areas in Brisbane, Australia (27 degrees 28' S, 153 degrees 2' E). We obtained data on the monthly counts of RRV cases in Brisbane between November 1998 and December 2001 by statistical local areas from the Queensland Department of Health and the monthly mosquito abundance from the Brisbane City Council. Correlation analysis was used to assess the pairwise relationships between mosquito density and the incidence of RRV disease. This study showed that the mosquito abundance of Aedes vigilax (Skuse), Culex annulirostris (Skuse), and Aedes vittiger (Skuse) were significantly associated with the monthly incidence of RRV in the coastline area, whereas Aedes vigilax, Culex annulirostris, and Aedes notoscriptus (Skuse) were significantly associated with the monthly incidence of RRV in the inland area. The results of the classification and regression tree (CART) analysis show that both occurrence and incidence of RRV were influenced by interactions between species in both coastal and inland regions. We found that there was an 89% chance for an occurrence of RRV if the abundance of Ae. vigilax was between 64 and 90 in the coastline region. There was an 80% chance for an occurrence of RRV if the density of Cx. annulirostris was between 53 and 74 in the inland area. The results of this study may have applications as a decision support tool in planning disease control of RRV and other mosquito-borne diseases.

  4. 17. ROSS POWERHOUSE: BUTTERFLY VALVE CONTROLS FOR UNIT 43. THE ...

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

    17. ROSS POWERHOUSE: BUTTERFLY VALVE CONTROLS FOR UNIT 43. THE BUTTERFLY VALVE LOCK INDICATES THE BUTTERFLY VALVE IS CLOSED AS UNIT 43 WAS SHUT DOWN FOR REPAIRS, 1989. - Skagit Power Development, Ross Powerhouse, On Skagit River, 10.7 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  5. An Inactivated Ross River Virus Vaccine Is Well Tolerated and Immunogenic in an Adult Population in a Randomized Phase 3 Trial

    PubMed Central

    van der Velden, Maikel V. W.; Portsmouth, Daniel; Draxler, Wolfgang; O'Rourke, Maria; Richmond, Peter; Hall, Stephen; McBride, William J. H.; Redfern, Andrew; Aaskov, John; Barrett, P. Noel; Aichinger, Gerald

    2014-01-01

    Ross River virus (RRV) is endemic in Australia and several South Pacific Islands. More than 90,000 cases of RRV disease, which is characterized by debilitating polyarthritis, were reported in Australia in the last 20 years. There is no vaccine available to prevent RRV disease. A phase 3 study was undertaken at 17 sites in Australia to investigate the safety and immunogenicity of an inactivated whole-virus Vero cell culture-derived RRV vaccine in 1,755 healthy younger adults aged 16 to 59 years and 209 healthy older adults aged ≥60 years. Participants received a 2.5-μg dose of Al(OH)3-adjuvanted RRV vaccine, with a second and third dose after 3 weeks and 6 months, respectively. Vaccine-induced RRV-specific neutralizing and total IgG antibody titers were measured after each immunization. Vaccine safety was monitored over the entire study period. The vaccine was safe and well-tolerated after each vaccination. No cases of arthritis resembling RRV disease were reported. The most frequently reported systemic reactions were headache, fatigue, and malaise; the most frequently reported injection site reactions were tenderness and pain. After the third immunization, 91.5% of the younger age group and 76.0% of the older age group achieved neutralizing antibody titers of ≥1:10; 89.1% of the younger age group and 70.9% of the older age group achieved enzyme-linked immunosorbent assay (ELISA) titers of ≥11 PanBio units. A whole-virus Vero cell culture-derived RRV vaccine is well tolerated in an adult population and induces antibody titers associated with protection from RRV disease in the majority of individuals. (This study is registered at www.clinicaltrials.gov under registration no. NCT01242670.) PMID:25540268

  6. Ross Ice Shelf

    Atmospheric Science Data Center

    2013-04-16

    ... to hatch their young this year due to a combination of huge icebergs grounded near Ross Island and an unprecedented amount of sea ice in the Ross Sea. The grounded icebergs and sea ice have increased the distance between the penguins' feeding ...

  7. John Ross, Cherokee Chief.

    ERIC Educational Resources Information Center

    Moulton, Gary Evan

    Emphasizing the dedication with which John Ross (1790-1866) labored to achieve Cherokee social and political cohesion, this biography details the historical and political events which influenced Ross's attempts to make the U.S. honor its treaty obligations and thwart the Federal "Removal Policy" (removal of American Indians from their…

  8. Victoria Land, Ross Sea, and Ross Ice Shelf, Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On December 19, 2001, MODIS acquired data that produced this image of Antarctica's Victoria Land, Ross Ice Shelf, and the Ross Sea. The coastline that runs up and down along the left side of the image denotes where Victoria Land (left) meets the Ross Ice Shelf (right). The Ross Ice Shelf is the world's largest floating body of ice, approximately the same size as France. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  9. Victoria Land, Ross Sea, and Ross Ice Shelf, Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On December 19, 2001, MODIS acquired data that produced this image of Antarctica's Victoria Land, Ross Ice Shelf, and the Ross Sea. The coastline that runs up and down along the left side of the image denotes where Victoria Land (left) meets the Ross Ice Shelf (right). The Ross Ice Shelf is the world's largest floating body of ice, approximately the same size as France. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  10. [Ross operation in Chile].

    PubMed

    Turner G, Eduardo; Muñoz C, Rodrigo; Cumsille G, Miguel; Iturra U, Sebastián; Strodthoff R, Pablo; Ulzurrún T, Nicolás; Rodríguez A, Juan

    2010-04-01

    Donald Ross introduced the pulmonary autograft for aortic valve replacement with reconstruction of the right ventricular outflow tract with a homograft. Despite its advantages over conventional valve prostheses, the Ross Operation is performed in a minority of patients who need an aortic valve replacement throughout the world. To report the operative and long term results of a series of patients subjected to Ross operation in Chile. Between 1996 and 2006, 131 patients aged 35+/-11 years (62% males) were subjected to an aortic root replacement with a pulmonary autograft and reconstruction of the right ventricular outflow tract with a pulmonary homograft. Seventy percent had congenital valve disease. Associated procedures were done in 39%. Patients were followed for a mean of 56+/-30 months. Operative mortality was 2.3%. Two patients had the autografts replaced intraoperatively because of tears in the proximal suture line and one within a month of the operation after suffering autograft endocarditis. At last follow up all patients are in functional class 1 or 2. Autograft reoperations were done in two patients who developed dilation with valve regurgitation (both had aortic regurgitation as primary indication for aortic valve replacement). Three patients required reoperation for pulmonary homograft dysfunction. Another three patients had uneventful pregnancies with normal newborns. Actuarial freedom from any reoperation at 10 years is 93%. The Ross Operation has low operative morbidity and mortality with excellent long term results. Reoperations have been rare within 10 years of follow up both for the autograft or the homograft.

  11. Ross during EVA 2

    NASA Image and Video Library

    1998-12-09

    S88-E-5093 (12-09-98) --- Astronaut Jerry L. Ross, mission specialist, requires artificial light to work during the second STS-88 space walk. Part of a pressurized mating adapter (PMA) is in the foreground. The photo was taken with an electronic still camera (ESC) at 23:49:36 GMT, Dec. 9.

  12. Bandura, Ross, and Ross: Observational Learning and the Bobo Doll

    ERIC Educational Resources Information Center

    Artino, Anthony R., Jr.

    2007-01-01

    Since the publication of their seminal article entitled, "Transmission of Aggression Through Imitation of Aggressive Models" (Bandura, Ross, & Ross, 1961), the work of Albert Bandura and his co-authors has had an immeasurable impact on the field of psychology, in general, and educational psychology, more specifically. The purpose of this report is…

  13. Antarctica - Ross Ice Shelf

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This color picture of Antarctica is one part of a mosaic of pictures covering the entire polar continent taken during the hours following Galileo's historic first encounter with its home planet. The view shows the Ross Ice Shelf to the right and its border with the sea. An occasional mountain can be seen poking through the ice near the McMurdo Station. It is late spring in Antarctica, so the sun never sets on the frigid, icy continent. This picture was taken about 6:20 p.m. PST on December 8, 1990. From top to bottom, the frame looks across about half of Antarctica.

  14. Antarctica - Ross Ice Shelf

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This color picture of Antarctica is one part of a mosaic of pictures covering the entire polar continent taken during the hours following Galileo's historic first encounter with its home planet. The view shows the Ross Ice Shelf to the right and its border with the sea. An occasional mountain can be seen poking through the ice near the McMurdo Station. It is late spring in Antarctica, so the sun never sets on the frigid, icy continent. This picture was taken about 6:20 p.m. PST on December 8, 1990. From top to bottom, the frame looks across about half of Antarctica.

  15. Identification and characterization of a ross river virus variant that grows persistently in macrophages, shows altered disease kinetics in a mouse model, and exhibits resistance to type I interferon.

    PubMed

    Lidbury, Brett A; Rulli, Nestor E; Musso, Cristina M; Cossetto, Susan B; Zaid, Ali; Suhrbier, Andreas; Rothenfluh, Harald S; Rolph, Michael S; Mahalingam, Suresh

    2011-06-01

    Alphaviruses, such as chikungunya virus, o'nyong-nyong virus, and Ross River virus (RRV), cause outbreaks of human rheumatic disease worldwide. RRV is a positive-sense single-stranded RNA virus endemic to Australia and Papua New Guinea. In this study, we sought to establish an in vitro model of RRV evolution in response to cellular antiviral defense mechanisms. RRV was able to establish persistent infection in activated macrophages, and a small-plaque variant (RRV(PERS)) was isolated after several weeks of culture. Nucleotide sequence analysis of RRV(PERS) found several nucleotide differences in the nonstructural protein (nsP) region of the RRV(PERS) genome. A point mutation was also detected in the E2 gene. Compared to the parent virus (RRV-T48), RRV(PERS) showed significantly enhanced resistance to beta interferon (IFN-β)-stimulated antiviral activity. RRV(PERS) infection of RAW 264.7 macrophages induced lower levels of IFN-β expression and production than infection with RRV-T48. RRV(PERS) was also able to inhibit type I IFN signaling. Mice infected with RRV(PERS) exhibited significantly enhanced disease severity and mortality compared to mice infected with RRV-T48. These results provide strong evidence that the cellular antiviral response can direct selective pressure for viral sequence evolution that impacts on virus fitness and sensitivity to alpha/beta IFN (IFN-α/β).

  16. Water-discharge determinations for the tidal reach of the Willamette River from Ross Island Bridge to Mile 10.3, Portland, Oregon

    USGS Publications Warehouse

    Dempster, G.R.; Lutz, Gale A.

    1968-01-01

    Water-discharge, velocity, and slope variations for a 3.7-mile-Iong tidal reach of the Willamette River at Portland, Oreg., were defined from discharge measurements and river stage data collected between July 1962 and January 1965. Observed water discharge during tide-affected flows, during floods, and during backwater from the Columbia River and recorded stages at each end of the river reach were used to determine water discharge from two mathematical models. These models use a finite-difference method to solve the equations of moderately unsteady open-channel streamflow, and discharges are computed by an electronic digital computer. Discharges computed by using the mathematical models compare satisfactorily with observed discharges, except during the period of backwater from the annual flood of the Columbia River. The flow resistance coefficients used in the models vary with discharge; for one model, the coefficients for discharges above 30,000 cfs (cubic feet per second) are 12 and 24 percent less than the coefficient used for discharges below 30,000 cfs. Daily mean discharges were determined by use of one mathematical model for approximately two-thirds of the water year, October 1963 through September 1964. Agreement of computed with routed daily mean discharges is fair; above 30,000 cfs, average differences between the two discharges are about 10 percent, and below 30,000 cfs, computed daily discharges are consistently greater (by as much as 25 percent) than routed discharges. The other model was used to compute discharges for the unusually high flood flows of December 1964.

  17. Ross ice shelf vibrations

    NASA Astrophysics Data System (ADS)

    Bromirski, P. D.; Diez, A.; Gerstoft, P.; Stephen, R. A.; Bolmer, T.; Wiens, D. A.; Aster, R. C.; Nyblade, A.

    2015-09-01

    Broadband seismic stations were deployed across the Ross Ice Shelf (RIS) in November 2014 to study ocean gravity wave-induced vibrations. Initial data from three stations 100 km from the RIS front and within 10 km of each other show both dispersed infragravity (IG) wave and ocean swell-generated signals resulting from waves that originate in the North Pacific. Spectral levels from 0.001 to 10 Hz have the highest accelerations in the IG band (0.0025-0.03 Hz). Polarization analyses indicate complex frequency-dependent particle motions, with energy in several frequency bands having distinctly different propagation characteristics. The dominant IG band signals exhibit predominantly horizontal propagation from the north. Particle motion analyses indicate retrograde elliptical particle motions in the IG band, consistent with these signals propagating as Rayleigh-Lamb (flexural) waves in the ice shelf/water cavity system that are excited by ocean wave interactions nearer the shelf front.

  18. Chikungunya Virus Glycoproteins Pseudotype with Lentiviral Vectors and Reveal a Broad Spectrum of Cellular Tropism

    PubMed Central

    Wang, Hua; Liu, Shuangchun; Yu, Lianhua; Sun, Lingfen; Qu, Ying

    2014-01-01

    Background Outbreaks of the Chikungunya virus (CHIKV) infection has been documented in over 40 countries, resulting in clinical symptoms characterized by fever and joint pain. Diagnosing CHIKV in a clinical lab setting is often omitted because of the high lab safety requirement. An infection system that mimics CHIKV infection will permit clinical evaluation of the production of neutralizing antibody for both disease diagnostics and treatment. Methodology/Principal Findings We generated a CHIKV construct expressing CHIKV structural proteins. This construct permits the production of CHIKV pseudo-viral particles with a luciferase reporter. The pseudo-virus was able to infect a wide range of cell lines. The pseudovirus could be neutralized by the addition of neutralizing antibodies from patients. Conclusions Taken together, we have developed a powerful system that can be handled at biosafety level 2 laboratories for evaluation of existence of CHIKV neutralizing antibodies. PMID:25333782

  19. Resting lymphocyte transduction with measles virus glycoprotein pseudotyped lentiviral vectors relies on CD46 and SLAM

    SciTech Connect

    Zhou Qi; Schneider, Irene C.; Gallet, Manuela; Kneissl, Sabrina; Buchholz, Christian J.

    2011-05-10

    The measles virus (MV) glycoproteins hemagglutinin (H) and fusion (F) were recently shown to mediate transduction of resting lymphocytes by lentiviral vectors. MV vaccine strains use CD46 or signaling lymphocyte activation molecule (SLAM) as receptor for cell entry. A panel of H protein mutants derived from vaccine strain or wild-type MVs that lost or gained CD46 or SLAM receptor usage were investigated for their ability to mediate gene transfer into unstimulated T lymphocytes. The results demonstrate that CD46 is sufficient for efficient vector particle association with unstimulated lymphocytes. For stable gene transfer into these cells, however, both MV receptors were found to be essential.

  20. Complement inhibition enables tumor delivery of LCMV glycoprotein pseudotyped viruses in the presence of antiviral antibodies

    PubMed Central

    Evgin, Laura; Ilkow, Carolina S; Bourgeois-Daigneault, Marie-Claude; de Souza, Christiano Tanese; Stubbert, Lawton; Huh, Michael S; Jennings, Victoria A; Marguerie, Monique; Acuna, Sergio A; Keller, Brian A; Lefebvre, Charles; Falls, Theresa; Le Boeuf, Fabrice; Auer, Rebecca A; Lambris, John D; McCart, J Andrea; Stojdl, David F; Bell, John C

    2016-01-01

    The systemic delivery of therapeutic viruses, such as oncolytic viruses or vaccines, is limited by the generation of neutralizing antibodies. While pseudotyping of rhabdoviruses with the lymphocytic choriomeningitis virus glycoprotein has previously allowed for multiple rounds of delivery in mice, this strategy has not translated to other animal models. For the first time, we provide experimental evidence that antibodies generated against the lymphocytic choriomeningitis virus glycoprotein mediate robust complement-dependent viral neutralization via activation of the classical pathway. We show that this phenotype can be capitalized upon to deliver maraba virus pseudotyped with the lymphocytic choriomeningitis virus glycoprotein in a Fischer rat model in the face of neutralizing antibody through the use of complement modulators. This finding changes the understanding of the humoral immune response to arenaviruses, and also describes methodology to deliver viral vectors to their therapeutic sites of action without the interference of neutralizing antibody. PMID:27909702

  1. Earth - Ross Ice Shelf, Antarctica

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This color picture of Antarctica is one part of a mosaic of pictures covering the entire Antarctic continent taken during the hours following Galileo's historic first encounter with its home planet. The view shows the Ross Ice Shelf. An occasional mountain can be seen poking through the ice. It is late spring in Antarctica, so the sun never sets on the frigid, icy continent. This picture was taken on December 8, 1990.

  2. Bloom in the Ross Sea

    NASA Image and Video Library

    2017-09-28

    NASA image acquired January 22, 2011 To see a detail of this image go to: www.flickr.com/photos/gsfc/5398237910 Every southern spring and summer, after the Sun has risen into its 24-hour circuit around the skies of Antarctica, the Ross Sea bursts with life. Floating, microscopic plants, known as phytoplankton, soak up the sunlight and the nutrients stirring in the Southern Ocean and grow into prodigious blooms. Those blooms become a great banquet for krill, fish, penguins, whales, and other marine species who carve out a living in the cool waters of the far south. This true-color image captures such a bloom in the Ross Sea on January 22, 2011, as viewed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite. Bright greens of plant-life have replaced the deep blues of open ocean water. The Ross Sea is a relatively shallow bay in the Antarctic coastline and due south from New Zealand. As the spring weather thaws the sea ice around Antarctica, areas of open water surrounded by ice—polynyas—open up on the continental shelf. In this open water, sunlight provides the fuel and various current systems provide nutrients from deeper waters to form blooms that can stretch 100 to 200 kilometers (60 to 120 miles). These blooms are among the largest in extent and abundance in the world. Scientists have hypothesized that the Modified Circumpolar Deep Water is the engine behind the blooms, stirring up just the right mix of trace metals and minerals from the deep to sustain plankton growth. This month, researchers aboard the U.S. icebreaking ship Nathaniel B. Palmer are cruising in the Ross Sea in search of the signatures of this current system. NASA image courtesy Norman Kuring, Ocean Color Team at NASA Goddard Space Flight Center. Caption by Mike Carlowicz, with information from Hugh Powell, COSEE-NOW. Instrument: Aqua - MODIS Credit: NASA Earth Observatory earthobservatory.nasa.gov/IOTD/view.php?id=48949 NASA Goddard Space Flight Center

  3. Bloom in the Ross Sea

    NASA Image and Video Library

    2017-09-28

    NASA image acquired January 22, 2011 Every southern spring and summer, after the Sun has risen into its 24-hour circuit around the skies of Antarctica, the Ross Sea bursts with life. Floating, microscopic plants, known as phytoplankton, soak up the sunlight and the nutrients stirring in the Southern Ocean and grow into prodigious blooms. Those blooms become a great banquet for krill, fish, penguins, whales, and other marine species who carve out a living in the cool waters of the far south. This true-color image captures such a bloom in the Ross Sea on January 22, 2011, as viewed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite. Bright greens of plant-life have replaced the deep blues of open ocean water. The Ross Sea is a relatively shallow bay in the Antarctic coastline and due south from New Zealand. As the spring weather thaws the sea ice around Antarctica, areas of open water surrounded by ice—polynyas—open up on the continental shelf. In this open water, sunlight provides the fuel and various current systems provide nutrients from deeper waters to form blooms that can stretch 100 to 200 kilometers (60 to 120 miles). These blooms are among the largest in extent and abundance in the world. Scientists have hypothesized that the Modified Circumpolar Deep Water is the engine behind the blooms, stirring up just the right mix of trace metals and minerals from the deep to sustain plankton growth. This month, researchers aboard the U.S. icebreaking ship Nathaniel B. Palmer are cruising in the Ross Sea in search of the signatures of this current system. NASA image courtesy Norman Kuring, Ocean Color Team at NASA Goddard Space Flight Center. Caption by Mike Carlowicz, with information from Hugh Powell, COSEE-NOW. Instrument: Aqua - MODIS Go here to download the full high res file: earthobservatory.nasa.gov/IOTD/view.php?id=48949 Credit: NASA Earth Observatory NASA image use policy. NASA Goddard Space Flight Center enables NASA

  4. Liquid hydrocarbons probable under Ross Sea

    USGS Publications Warehouse

    Cooper, A. K.; Davey, F.J.; Hinz, K.

    1988-01-01

    Thick glacial strata, which have no source-rock potential, cover the Ross Sea. If these strata persist to great depths, then hydrocarbon-generation prospects will be poor. Deeply buried strata within Ross Sea rift-grabens, if like other Gondwana rift-deposits, could have good potential for hydrocarbon generation. Current hydrocarbon assessments of the Ross Sea and adjacent areas must be considered highly speculative because the deeply buried rift(?) strata have not been sampled in situ. The assessment of the Ross Sea relies on geophysical/geologic data, two-stage rift models, and data from formerly nearby Gondwana rift-basins. We conclude that conditions favorable for hydrocarbon generation and entrapment are likely throughout the Ross Sea, and especially in the Victoria Land basin, if adequate source beds exist. -Authors

  5. Sir Donald Ross, pioneer aortic valve surgeon.

    PubMed

    Wheatley, David

    2015-06-01

    Tribute to Sir Donald Ross by David Wheatley, as read by Robert Kleinloog, President, Society of Cardiothoracic Surgeons of South Africa at the Annual Congress of the South African Heart Association 19 October 2014.

  6. The South Pole and the Ross Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image shows a rare clear view of the South Pole (lower right) and the Ross Sea, Antarctica. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) acquired the scene on December 26, 2001. The geographic South Pole is located in the center of Antarctica, at an altitude of 2,900 meters (9,300 feet). It rests on a continent-wide ice sheet that is 2,870 m thick, with the underlying bedrock only 30 m (98 feet) above sea level. The ice underlying the South Pole is as much as 140,000 years old, and is currently accumulating at about 82 cm (32 inches) per year. Roughly 2,500 km (1,550 miles) away is the green water of the Ross Sea, which indicates the presence of large numbers of phytoplankton. This is a highly productive part of the world's oceans. Also note the ice gathered around McMurdo Sound, seen toward the lefthand shoreline of the Ross Sea, at the edge of the Ross Ice Shelf. According to National Science Foundation researchers, this ice is making it difficult for penguins to reach their food supply. Separating the continental Antarctic ice sheet from the Ross Sea are the Queen Maud Mountains and the Ross Ice Shelf. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  7. The South Pole and the Ross Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image shows a rare clear view of the South Pole (lower right) and the Ross Sea, Antarctica. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) acquired the scene on December 26, 2001. The geographic South Pole is located in the center of Antarctica, at an altitude of 2,900 meters (9,300 feet). It rests on a continent-wide ice sheet that is 2,870 m thick, with the underlying bedrock only 30 m (98 feet) above sea level. The ice underlying the South Pole is as much as 140,000 years old, and is currently accumulating at about 82 cm (32 inches) per year. Roughly 2,500 km (1,550 miles) away is the green water of the Ross Sea, which indicates the presence of large numbers of phytoplankton. This is a highly productive part of the world's oceans. Also note the ice gathered around McMurdo Sound, seen toward the lefthand shoreline of the Ross Sea, at the edge of the Ross Ice Shelf. According to National Science Foundation researchers, this ice is making it difficult for penguins to reach their food supply. Separating the continental Antarctic ice sheet from the Ross Sea are the Queen Maud Mountains and the Ross Ice Shelf. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  8. STS-110 Crew Interview: Jerry Ross

    NASA Technical Reports Server (NTRS)

    2002-01-01

    STS-110 Mission Specialist Jerry Ross is seen during this preflight interview, where he gives a quick overview of the mission before answering questions about his inspiration to become an astronaut and his career path. Ross outlines his role in the mission in general, and specifically during the docking and extravehicular activities (EVAs). He describes the payload (S0 Truss and Mobile Transporter) and the dry run installation of the S0 truss that will take place the day before the EVA for the actual installation. Ross discusses the planned EVAs in detail and outlines what supplies will be left for the resident crew of the International Space Station (ISS). He ends with his thoughts on the most valuable aspect of the ISS.

  9. Improvements in Ross type astrometric objectives

    NASA Technical Reports Server (NTRS)

    Baker, J.

    1971-01-01

    It is shown that aspheric deformations of the first and fourth elements of the four element Ross objective can be introduced to permit one to obtain improved color corrections for astrometric purposes. The usual monochromatic aberrations are as well corrected as for the standard Ross lens. In addition, one can eliminate or reduce additional aberrations, such as secondary spectrum, chromatic spherical aberration, chromatic coma and chromatic distortion. The resulting objectives are suitable for use as intermediate and long focus astrometric objectives covering large angle fields.

  10. Retargeting vesicular stomatitis virus glycoprotein pseudotyped lentiviral vectors with enhanced stability by in situ synthesized polymer shell.

    PubMed

    Liang, Min; Yan, Ming; Lu, Yunfeng; Chen, Irvin S Y

    2013-02-01

    The ability to introduce transgenes with precise specificity to the desired target cells or tissues is key to a more facile application of genetic therapy. Here, we describe a novel method using nanotechnology to generate lentiviral vectors with altered recognition of host cell receptor specificity. Briefly, the infectivity of the vesicular stomatitis virus glycoprotein (VSV-G) pseudotyped lentiviral vectors was shielded by a thin polymer shell synthesized in situ onto the viral envelope, and new binding ability was conferred to the shielded virus by introducing acrylamide-tailored cyclic arginine-glycine-aspartic acid (cRGD) peptide to the polymer shell. We termed the resulting virus "targeting nanovirus." The targeting nanovirus had similar titer with VSV-G pseudotypes and specifically transduced Hela cells with high transduction efficiency. In addition, the encapsulation of the VSV-G pseudotyped lentivirus by the polymer shell did not change the pathway that VSV-G pseudotypes enter and fuse with cells, as well as later events such as reverse transcription and gene expression. Furthermore, the targeting nanovirus possessed enhanced stability in the presence of human serum, indicating protection of the virus by the polymer shell from human serum complement inactivation. This novel use of nanotechnology demonstrates proof of concept for an approach that could be more generally applied for redirecting viral vectors for laboratory and clinical purposes.

  11. Retargeting Vesicular Stomatitis Virus Glycoprotein Pseudotyped Lentiviral Vectors with Enhanced Stability by In Situ Synthesized Polymer Shell

    PubMed Central

    Liang, Min; Yan, Ming; Lu, Yunfeng

    2013-01-01

    Abstract The ability to introduce transgenes with precise specificity to the desired target cells or tissues is key to a more facile application of genetic therapy. Here, we describe a novel method using nanotechnology to generate lentiviral vectors with altered recognition of host cell receptor specificity. Briefly, the infectivity of the vesicular stomatitis virus glycoprotein (VSV-G) pseudotyped lentiviral vectors was shielded by a thin polymer shell synthesized in situ onto the viral envelope, and new binding ability was conferred to the shielded virus by introducing acrylamide-tailored cyclic arginine-glycine-aspartic acid (cRGD) peptide to the polymer shell. We termed the resulting virus “targeting nanovirus.” The targeting nanovirus had similar titer with VSV-G pseudotypes and specifically transduced Hela cells with high transduction efficiency. In addition, the encapsulation of the VSV-G pseudotyped lentivirus by the polymer shell did not change the pathway that VSV-G pseudotypes enter and fuse with cells, as well as later events such as reverse transcription and gene expression. Furthermore, the targeting nanovirus possessed enhanced stability in the presence of human serum, indicating protection of the virus by the polymer shell from human serum complement inactivation. This novel use of nanotechnology demonstrates proof of concept for an approach that could be more generally applied for redirecting viral vectors for laboratory and clinical purposes. PMID:23327104

  12. Icebergs in the Ross Sea, Antarctica

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Two large icebergs, designated B-15A and C-16, are captured in this MISR nadir camera view of the Ross Ice Shelf and Ross Sea in Antarctica. The image was acquired on December 10, 2000 during Terra orbit 5220.

    Iceberg C-16 calved off the ice shelf in late September and is nearly 50 kilometers in length. It is seen here having migrated to the vicinity of Cape Bird on Ross Island. The initial letter designation in an iceberg's name denotes the longitudinal quadrant in which it is first seen, and new icebergs sighted in that quadrant are sequentially numbered. B-15 divided from the ice shelf last March, and initially was nearly as large as the state of Connecticut. It has since broken up into several pieces, hence the final letter designation in the berg shown in this image.

    Ross Island lies between 77 and 78 degrees south latitude, and consists of several volcanic peaks, of which the still active Mt. Erebus is the tallest (3794 meters). It overlooks McMurdo Station, a U.S. research facility located near the tip of the island's Hut Point Peninsula.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  13. Icebergs in the Ross Sea, Antarctica

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Two large icebergs, designated B-15A and C-16, are captured in this MISR nadir camera view of the Ross Ice Shelf and Ross Sea in Antarctica. The image was acquired on December 10, 2000 during Terra orbit 5220.

    Iceberg C-16 calved off the ice shelf in late September and is nearly 50 kilometers in length. It is seen here having migrated to the vicinity of Cape Bird on Ross Island. The initial letter designation in an iceberg's name denotes the longitudinal quadrant in which it is first seen, and new icebergs sighted in that quadrant are sequentially numbered. B-15 divided from the ice shelf last March, and initially was nearly as large as the state of Connecticut. It has since broken up into several pieces, hence the final letter designation in the berg shown in this image.

    Ross Island lies between 77 and 78 degrees south latitude, and consists of several volcanic peaks, of which the still active Mt. Erebus is the tallest (3794 meters). It overlooks McMurdo Station, a U.S. research facility located near the tip of the island's Hut Point Peninsula.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  14. Rapid early-Holocene deglaciation in the Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Spector, Perry; Stone, John; Cowdery, Seth G.; Hall, Brenda; Conway, Howard; Bromley, Gordon

    2017-08-01

    Deglaciation of the Ross Sea following the last ice age provides an important opportunity to examine the stability of marine ice sheets and their susceptibility to changing environmental conditions. Insufficient chronology for Ross Sea deglaciation has helped sustain (i) the theory that this region contributed significantly to Meltwater Pulse 1A (MWP-1A) and (ii) the idea that Ross Sea grounding-line retreat occurred in a "swinging gate" pattern hinged north of Roosevelt Island. We present deglaciation records from southern Transantarctic Mountain glaciers, which delivered ice to the central Ross Sea. Abrupt thinning of these glaciers 9-8 kyr B.P. coincided with deglaciation of the Scott Coast, ˜800 km to the north, and ended with the Ross Sea grounding line near Shackleton Glacier. This deglaciation removed grounded ice from most of the central and western Ross Sea in less than 2 kyr. The Ross Sea Sector neither contributed nor responded significantly to MWP-1A.

  15. Climatological aspects of mesoscale cyclogenesis over the Ross Sea and Ross Ice shelf regions of Antarctica

    SciTech Connect

    Carrasco, J.F.; Bromwich, D.H.

    1994-11-01

    A one-year (1988) statistical study of mesoscale cyclogenesis near Terra Nova Bay and Byrd Glacier, Antarctica, was conducted using high-resolution digital satellite imagery and automatic weather station data. Results indicate that on average two (one) mesoscale cyclones form near Terra Nova Bay (Byrd Glacier) each week, confirming these two locations as mesoscale cyclogeneis areas. The maximum (minimum) weekly frequency of mesoscale cyclones occurred during the summer (winter). The satellite survey of mesoscale vortices was extended over the Ross Sea and Ross Ice Shelf. Results suggest southern Marie Byrd Land as another area of mesoscale cyclone formation. Also, frequent mesoscale cyclonic activity was noted over the Ross Sea and Ross Ice Shelf, where, on average, six and three mesoscale vortices were observed each week, respectively, with maximum (minimum) frequency during summer (winter) in both regions. The majority (70-80%) of the vortices were of comma-cloud type and were shallow. Only around 10% of the vortices near Terra Nova Bay and Byrd Glacier were classified as deep vortices, while over the Ross Sea and Ross Ice Shelf around 20% were found to be deep. The average large-scale pattern associated with cyclogenesis days near Terra Nova Bay suggests a slight decrease in the sea level pressure and 500-hPa geopotential height to the northwest of this area with respect to the annual average. This may be an indication of the average position of synoptic-scale cyclones entering the Ross Sea region. Comparison with a similar study but for 1984-85 shows that the overall mesoscale cyclogenesis activity was similar during the three years, but 1985 was found to be the year with greater occurrence of {open_quotes}significant{close_quotes} mesoscales cyclones. The large-scale pattern indicates that this greater activity is related to a deeper circumpolar trough and 500-hPa polar vortex for 1985 in comparison to 1984 and 1988. 64 refs., 13 figs., 5 tabs.

  16. STS-88 Crew Interview: Jerry Ross

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Jerry Ross discusses the seven-day mission that will be highlighted by the mating of the U.S.-built Node 1 station element to the Functional Energy Block (FGB) which will already be in orbit, and two spacewalks to connect power and data transmission cables between the Node and the FGB. Node 1 will be the first Space Station hardware delivered by the Space Shuttle. He also disscusses the assembly sequence. The crew will conduct a series of rendezvous maneuvers similar to those conducted on other Shuttle missions to reach the orbiting FGB. Once the two elements are docked, Ross and Newman will conduct two scheduled spacewalks to connect power and data cables between the Node, PMAs and the FGB. The day following the spacewalks, Endeavour will undock from the two components, completing the first Space Station assembly mission.

  17. Iceberg B-15, Ross Ice Shelf, Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Iceberg B-15 broke from the Ross Ice Shelf in Antarctica in late March. Among the largest ever observed, the new iceberg is approximately 170 miles long x 25 miles wide. Its 4,250 square-mile area is nearly as large as the state of Connecticut. The iceberg was formed from glacial ice moving off the Antarctic continent and calved along pre-existing cracks in the Ross Ice Shelf near Roosevelt Island. The calving of the iceberg essentially moves the northern boundary of the ice shelf about 25 miles to the south, a loss that would normally take the ice shelf as long as 50-100 years to replace. This infrared image was acquired by the DMSP (Defense Meteorological Satellite Program) F-13 satellite on April 13, 2000. For more images see Antarctic Meteorological Research Center Image courtesy of the University of Wisconsin - Madison, Space Science and Engineering Center, Antarctic Meteorological Research Center

  18. Ross Ice Shelf, Antarctic Ice and Clouds

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In this view of Antarctic ice and clouds, (56.5S, 152.0W), the Ross Ice Shelf of Antarctica is almost totally clear, showing stress cracks in the ice surface caused by wind and tidal drift. Clouds on the eastern edge of the picture are associated with an Antarctic cyclone. Winds stirred up these storms have been known to reach hurricane force.

  19. Dynamics of the Ross Ice Shelf

    NASA Technical Reports Server (NTRS)

    Casassa, Gino; Turner, John

    1991-01-01

    The changing flow of the Ross Ice Shelf is described based on AVHRR data from 18 cloud-free images which evince flow stripes and form the data for a glaciological map. The discharge region of the valley glaciers in the Transantarctic Mountains is found to have curvilinear stripes, and the brightness contrast is enhanced to examine the feature. The map of the region also shows rifts, ridge crests, surface folds, and large-scale lineaments.

  20. Phenolic compounds in Ross Sea water

    NASA Astrophysics Data System (ADS)

    Zangrando, Roberta; Barbaro, Elena; Gambaro, Andrea; Barbante, Carlo; Corami, Fabiana; Kehrwald, Natalie; Capodaglio, Gabriele

    2016-04-01

    Phenolic compounds are semi-volatile organic compounds produced during biomass burning and lignin degradation in water. In atmospheric and paleoclimatic ice cores studies, these compounds are used as biomarkers of wood combustion and supply information on the type of combusted biomass. Phenolic compounds are therefore indicators of paleoclimatic interest. Recent studies of Antarctic aerosols highlighted that phenolic compounds in Antarctica are not exclusively attributable to biomass burning but also derive from marine sources. In order to study the marine contribution to aerosols we developed an analytical method to determine the concentration of vanillic acid, vanillin, p-coumaric acid, syringic acid, isovanillic acid, homovanillic acid, syringaldehyde, acetosyringone and acetovanillone present in dissolved and particle phases in Sea Ross waters using HPLC-MS/MS. The analytical method was validated and used to quantify phenolic compounds in 28 sea water samples collected during a 2012 Ross Sea R/V cruise. The observed compounds were vanillic acid, vanillin, acetovanillone and p-coumaric acid with concentrations in the ng/L range. Higher concentrations of analytes were present in the dissolved phase than in the particle phase. Sample concentrations were greatest in the coastal, surficial and less saline Ross Sea waters near Victoria Land.

  1. 33 CFR 117.949 - Tennessee River.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Tennessee River. 117.949 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Tennessee § 117.949 Tennessee River. The draws of the Chief John Ross Bridge over the Tennessee River, mile 464.1, at Chattanooga, and the Southern Railway...

  2. 33 CFR 117.949 - Tennessee River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Tennessee River. 117.949 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Tennessee § 117.949 Tennessee River. The draws of the Chief John Ross Bridge over the Tennessee River, mile 464.1, at Chattanooga, and the Southern Railway...

  3. 33 CFR 117.949 - Tennessee River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Tennessee River. 117.949 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Tennessee § 117.949 Tennessee River. The draws of the Chief John Ross Bridge over the Tennessee River, mile 464.1, at Chattanooga, and the Southern Railway...

  4. 33 CFR 117.949 - Tennessee River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Tennessee River. 117.949 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Tennessee § 117.949 Tennessee River. The draws of the Chief John Ross Bridge over the Tennessee River, mile 464.1, at Chattanooga, and the Southern Railway...

  5. 33 CFR 117.949 - Tennessee River.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Tennessee River. 117.949 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Tennessee § 117.949 Tennessee River. The draws of the Chief John Ross Bridge over the Tennessee River, mile 464.1, at Chattanooga, and the Southern Railway...

  6. 33 CFR 165.1337 - Regulated Navigation Area, Zidell Waterfront Property, Willamette River, OR.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... approximate river mile 14.2 near the Ross Island Bridge and approximate river mile 13.5 near the Marquam Bridge. (b) Regulations. All vessels are prohibited from anchoring, dragging, dredging, or trawling in... additional information and requirements. ...

  7. Results of geophysical research in Ross Sea

    SciTech Connect

    Hinz, K.

    1987-05-01

    The Ross Sea is underlain from the east to the west by three north-south-trending sedimentary basins: the Eastern basin (east of the 180/sup 0/ meridian), the Central basin (along 175/sup 0/), and the Victoria Land basin. In the center of the Eastern basin, the thickness of the sediments generally ranges between 3000 and 6000 m. The pre-late Oligocene sediments occur only in the center of the basin. There are no indications of block faulting in the sedimentary sequence, indicating that synsedimentary subsidence has been the dominant tectonic process. A broad basement high, the Central High, lies to the west of the Eastern basin. The top of basement is a peneplain over large parts of the high. The overlying sediments are mostly younger than Oligocene. The Central basin lies to the west of the Central High, extends approximately north-south through the central Ross Sea. Sedimentary thicknesses in excess of 6000 m were observed. A relatively narrow basement high, trending north-south, separates the Central basin from the complex Victoria Land basin. The Victoria Land basin is a 150-km wide basin that extends from the Ross Ice shelf to 75/sup 0/S. It is bounded to the north by a shallow and characteristically planated basement high, the Coulman High, and to the west by the uplifted Transantarctic Mountains. The Victoria Land basin is subdivided by north-south-trending zones of volcanic/magmatic intrusions, probably equivalents of the Neogene Hallett Volcanics and McMurdo Volcanics, respectively, that affected the Victoria Land basin, resulting in uplift and inversion of parts of the basin.

  8. Career Profile- Jim Ross, Aerial Photographer

    NASA Image and Video Library

    2016-12-21

    Check out what it takes to “capture the moment” at Mach speeds. The stunning aerial imagery of NASA Armstrong Flight Research Center comes from well-skilled photographers like Jim Ross, Photo Lead. This career profile video highlights Jim’s job responsibilities in documenting aircraft hardware installations, aerial research, and mission work that happens both on center and around the world. During Jim’s 27-year career, he has logged over 800 flight hours in twelve different types of aircraft.

  9. Bloom in the Ross Sea [detail

    NASA Image and Video Library

    2017-09-27

    NASA image acquired January 22, 2011 To view the full image go to: www.flickr.com/photos/gsfc/5397636843 Every southern spring and summer, after the Sun has risen into its 24-hour circuit around the skies of Antarctica, the Ross Sea bursts with life. Floating, microscopic plants, known as phytoplankton, soak up the sunlight and the nutrients stirring in the Southern Ocean and grow into prodigious blooms. Those blooms become a great banquet for krill, fish, penguins, whales, and other marine species who carve out a living in the cool waters of the far south. This true-color image captures such a bloom in the Ross Sea on January 22, 2011, as viewed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite. Bright greens of plant-life have replaced the deep blues of open ocean water. The Ross Sea is a relatively shallow bay in the Antarctic coastline and due south from New Zealand. As the spring weather thaws the sea ice around Antarctica, areas of open water surrounded by ice—polynyas—open up on the continental shelf. In this open water, sunlight provides the fuel and various current systems provide nutrients from deeper waters to form blooms that can stretch 100 to 200 kilometers (60 to 120 miles). These blooms are among the largest in extent and abundance in the world. Scientists have hypothesized that the Modified Circumpolar Deep Water is the engine behind the blooms, stirring up just the right mix of trace metals and minerals from the deep to sustain plankton growth. This month, researchers aboard the U.S. icebreaking ship Nathaniel B. Palmer are cruising in the Ross Sea in search of the signatures of this current system. NASA image courtesy Norman Kuring, Ocean Color Team at NASA Goddard Space Flight Center. Caption by Mike Carlowicz, with information from Hugh Powell, COSEE-NOW. Instrument: Aqua - MODIS For more info go to: earthobservatory.nasa.gov/IOTD/view.php?id=48949 Credit: NASA Earth Observatory NASA Goddard Space

  10. Rivers

    USGS Publications Warehouse

    Leopold, Luna Bergere

    1962-01-01

    Rivers are both the means and the routes by which the products of continental weathering are carried to the oceans of the world. Except in the most arid areas more water falls as precipitation than is lost by evaporation and transpiration from the land surface to the atmosphere. Thus there is an excess of water, which must flow to the ocean. Rivers, then, are the routes by which this excess water flows to the ultimate base level. The excess of precipitation over evaporation and transpiration provides the flow of rivers and springs, recharges ground-water storage, and is the supply from which man draws water for his needs.

  11. Elisabeth Kubler-Ross as a Religious Leader.

    ERIC Educational Resources Information Center

    Klass, Dennis; Hutch, Richard A.

    1986-01-01

    Considers Elisabeth Kubler-Ross as a charismatic religious leader and examines the feminine quality of her message and leadership style. An examination of the prospects for an enduring cultural innovation based on Kubler-Ross's work concludes that her leadership does not conform to conditions necessary for institutionalization of her charismatic…

  12. The ocean tide in the southern Ross Sea

    NASA Astrophysics Data System (ADS)

    Williams, Richard T.; Robinson, Edwin S.

    1980-11-01

    A survey of the ocean tide in the southern Ross Sea was done by measuring tidal variations of gravity at nine locations on the floating Ross Ice Shelf. Tidal water level fluctuations were calculated from recordings between 29 days and 58 days long of the periodic variation in gravity on the ice shelf surface that is caused by tidal changes in elevation and water mass. Conventional tide gauge measurements from McMurdo Sound were included in the survey. The data indicate that the Ross Sea tide is principally diurnal. Along the northern margin of the Ross Ice Shelf the tropic (diurnal spring) tidal range is between 1 m and ?; m. The range increases to more than 2 m in the southernmost part of the Ross Sea. It is more than 3 times larger than the equatorial (diurnal neap) tidal range. Amplitudes of the principal diurnal constituents K1 P1 and O1 are apparently magnified by a condition of diurnal resonance in the Ross Sea. This would be expected because wavelengths of the diurnal harmonic constituents are approximately 4 times the length of the Ross Sea in the direction of propagation. The diurnal constituent amplitudes also appear to vary proportionally with the fourth root of the water depth as predicted from the theory of long wave propagation in a canal. Semidiurnal constituents M2, S2, and N2 have small amplitudes and appear to progress clockwise around amphidromes located beneath the northwestern part of the Ross Ice Shelf.

  13. Elisabeth Kubler-Ross as a Religious Leader.

    ERIC Educational Resources Information Center

    Klass, Dennis; Hutch, Richard A.

    1986-01-01

    Considers Elisabeth Kubler-Ross as a charismatic religious leader and examines the feminine quality of her message and leadership style. An examination of the prospects for an enduring cultural innovation based on Kubler-Ross's work concludes that her leadership does not conform to conditions necessary for institutionalization of her charismatic…

  14. Ross opens Tool Stowage Assembly on ODS support structure

    NASA Image and Video Library

    1998-12-10

    S88-E-5104 (12-10-98) With the Shuttle in a "night side" position, astronaut Jerry L. Ross, mission specialist, uses artificial light during the second STS-88 space walk. Ross is near a pressurized module adapter (PMA) on Endeavour's port side. The photo was taken with an electronic still camera (ESC) at 03:10:00 GMT, Dec. 10.

  15. Relationships in Areal Variability: The Ross Sea Polynya and Ice

    NASA Astrophysics Data System (ADS)

    Ward, Jason Michael

    General increases in Antarctic sea ice coverage occur primarily in the Ross Sea. This study investigates the Ross Sea Polynya's relationship with the Ross Sea ice areal coverage. A unique, relatively long term Ross Sea Polynya area dataset was created through the application of the Polynya Signature Simulation Method (PSSM) onto Special Sensor Microwave Imager (SSM/I) data inputs. Bivariate regression analyses were used to determine the relationships, at the 95% confidence level, between Ross Sea Polynya and ice areal trends, annual seasonalities, and anomalies at the full temporal scale as well as the monthly level. Polynya and sea ice have significant positive relationships in the late austral summer and early spring (February to March), and a significant negative relationship in the late austral winter (August). The areal anomalies only had a significant relationship in February, while the trends were not correlated at any time.

  16. Seismic Stratigraphy Of The Ross Island Flexural Moat Under Western Mcmurdo-Ross Ice Shelf, Antarctica

    NASA Astrophysics Data System (ADS)

    Horgan, H.; Naish, T.; Bannister, S.; Balfour, N.; Wilson, G.; Finnemore, F.

    2003-04-01

    Ross Island is a volcanic complex that began forming with the emplacement Mount Bird around 5 million years ago, though it has developed most significantly within the last 1 million years with the emplacement of the c. 4km high Mount Erebus. Throughout this time, loading of the lithosphere by this volcanic complex has warped the underlying crust into a subcircular submarine depression that has been accumulating sediment in series of flexural moat basins around the periphery of the island. Due to the depth of the floor of the depression (800-1000 m below sea level today), the sediment fill has largely escaped subsequent erosion by grounded ice of the McMurdo and Ross Ice Shelves (MRIS) and Ross Ice Sheet. Our interest is in the 1.5 km-thick sedimentary record that now lies beneath the deepest part of the depression and is covered by the MRIS. The sediments here have the potential to provide a continuous and high resolution (10^2-10^3 year) record back to 5 million years of the past behaviour of the MRIS and its influence on bottom water production in Ross Sea. The flexural moat basin-fill between the volcanic complexes of Ross and White Islands, which because of its remoteness is only now being investigated for the first time, is in a key location beneath the north western corner of the Ross Ice Shelf (RIS) where it flows into the McMurdo Ice Shelf (MIS). This site forms one of the 4 objectives of the ANDRILL Programme and is scheduled for drilling in 2005. Here we present new multi-channel seismic reflection data from over-ice shelf surveys conducted between 2001-2003, that elucidate the geometry and stratigraphy of the flexural-moat basin-fill and its relationship to the adjacent volcanics. We illustrate the proposed drill sites and make an initial prognosis of the sedimentary fill. The uppermost c. 500 m of the sedimentary succession is expected to be fine-grained muds with occasional glacigene sediment and layers of volcanic ash. Underlying strata may become

  17. Use of acoustic technology to aid in the regulation of Ross Barnett Reservoir near Jackson, Mississippi: Trials and tribulations

    USGS Publications Warehouse

    Storm, J.B.

    2004-01-01

    The U.S. Geological Survey is computing continuous discharge of the Pearl River at the upper end of the Ross Barnett Reservoir near Jackson, Mississippi, using acoustic technology and conventional streamgaging methods. The computed inflow is posted "real-time" to the Mississippi District's web page where it can be monitored by the Pearl River Valley Water Supply District (PRVWSD) to aid in reservoir regulation. The use of this technology to determine discharge allows the PRVWSD to prepare for headwater flooding conditions ahead of time and adjust reservoir outflow accordingly. Hydraulic and acoustic problems inherent to this site have presented problems not normally encountered at a typical streamgaging site. Copyright ASCE 2004.

  18. The Paediatric Cardiology Hall of Fame – Donald Nixon Ross.

    PubMed

    Somerville, Jane

    2015-10-01

    Donald Nixon Ross, FRCS (4 October 1922 to 7 July 2014) was a South African-born British cardiothoracic surgeon, who developed the pulmonary autograft, known as the Ross procedure, for the treatment of aortic valve disease, and also performed the first heart transplant in the United Kingdom in 1968. This paper, written by Jane Somerville, Professor of Cardiology [Retired], Imperial College London, London, United Kingdom, provides the personal recollections about Donald Ross from Jane Somerville, and thus provides a unique snapshot of cardiac surgical history.

  19. An overview of the NSCAT/N-ROSS program

    NASA Technical Reports Server (NTRS)

    Martin, B. D.; Freilich, Michael H.; Li, F. K.; Callahan, Phillip S.

    1986-01-01

    The NASA Scatterometer (NSCAT) to fly on the U.S. Navy Remote Ocean Sensing System (N-ROSS) mission is presented. The overall N-ROSS mission, the NSCAT flight instrument and groundbased data processing/distribution system, and NASA-supported science and verification activities are described. The N-ROSS system is designed to provide measurements of near-surface wind, ocean topography, wave height, sea-surface temperature, and atmospheric water content over the global oceans. The NSCAT is an improved version of the Seasat scatterometer. It will measure near surface vector winds.

  20. Seismic Stratigraphy of the Ross Island Flexural Basin, West Antarctica

    NASA Astrophysics Data System (ADS)

    Wenman, C. P.; Harry, D. L.; Jha, S.

    2014-12-01

    Marine seismic reflection data collected over the past 30+ years in the Ross Sea region of southwest Antarctica has been tied to the ANDRILL and CIROS boreholes to develop a seismic stratigraphic model that constrains the spatial and temporal evolution of the flexural basin surrounding Ross Island. Ross Island was formed from 4.6 Ma to present by extrusive volcanism in the Ross Sea at the southern end of the Terror Rift. Preliminary mapping has identified a hinge zone trending northeastward from Mt. Bird, separating the well-developed flexural moat on the west side of the island from sub-horizontal strata on the northeast and east sides. The flexural moat on the west and north-northwest sides of the island is approximately 40-45 km wide with sediment fill thickness of roughly 1100 m. Seismic lines to the east and northeast of the island do not indicate the presence of a flexural moat. Instead, the thickness of strata on the east side of the island that are time-equivalent to the infill of the flexural moat on the west side remains constant from the Coulman High westward to within ~28 km of Ross Island (the landward extent of the seismic data coverage). The concordant post-Miocene strata on the east and northeast sides of Ross Island imply either that the flexural basin does not extend more than ~28 km eastward from the Ross Island shoreline, or that the flexural basin is not present on that side of the island. The first scenario requires that the elastic strength of the lithosphere differ on either side of the hinge. The second scenario can be explained by a mechanical rupture in the lithosphere beneath Ross Island, with Ross Island acting as an end-load on a mechanical half-plate that forms the lithosphere beneath Ross Island and westward. In this model, the lithosphere east of Ross Island and the hinge forms a second half-plate, bearing little or none of the Ross Island volcanic load.

  1. 27 CFR 9.221 - Fort Ross-Seaview.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Fort Ross Road with the Middle Branch of Russian Gulch Creek, and then proceed south along that creek... line meanders north then south around the West Branch of Russian Gulch, returning to the beginning...

  2. 27 CFR 9.221 - Fort Ross-Seaview.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Fort Ross Road with the Middle Branch of Russian Gulch Creek, and then proceed south along that creek... line meanders north then south around the West Branch of Russian Gulch, returning to the beginning...

  3. 27 CFR 9.221 - Fort Ross-Seaview.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Fort Ross Road with the Middle Branch of Russian Gulch Creek, and then proceed south along that creek... line meanders north then south around the West Branch of Russian Gulch, returning to the beginning...

  4. Cretaceous and Tertiary extension throughout the Ross Sea, Antarctica

    USGS Publications Warehouse

    Decesari, Robert C.; Wilson, Douglas C.; Luyendyk, Bruce P.; Faulkner, Michael

    2007-01-01

    Marine geophysical data from the deep sea adjacent to the Ross Sea, Antarctica suggest that 70 km of extension occurred between East and West Antarctica from 46 to 2 Ma. The Northern and Victoria Land Basins in the western Ross Sea adjacent to the Transantarctic Mountains accommodated 95 km of this extension. Several kilometers of Oligocene sediments are found in the Central Trough and Eastern Basin in the eastern Ross Sea. Subsidence modeling accounts for these accumulations with about 40 km of extension in each basin centered on 35 Ma; therefore Ross Sea-wide Tertiary extension was comparable to extension in the deep-sea system. The early Tertiary geometry was of one oceanic rift that branched into at least three rifts in the continental lithosphere. This pattern is likely due to the contrast of physical properties and thermal state between the two different lithospheres at the continent-ocean boundary.

  5. The Ross II procedure: pulmonary autograft in the mitral position.

    PubMed

    Athanasiou, Thanos; Cherian, Ashok; Ross, Donald

    2004-10-01

    The surgical management of mitral valve disease in women of childbearing age, young patients, and children with congenital mitral valve defects is made difficult by the prospect of lifelong anticoagulation. We suggest the use of a pulmonary autograft in the mitral position (Ross II procedure) as an alternative surgical technique. We present a review of the literature, historical perspectives, indications, selection criteria, and surgical technique for the Ross II procedure. Our literature search identified 14 studies that reported results from the Ross II operation. Performed in 103 patients, the overall in-hospital mortality was 7 (6.7%), with a late mortality of 10 (9%). Although further research is needed, current evidence suggests the Ross II operation is a valuable alternative in low-risk young patients where valve durability and the complication rate from other procedures is unsatisfactory and anticoagulation not ideal.

  6. ROSS Skills, Knowledge, and Abilities Training Evaluation. Gaps and Recommendations

    SciTech Connect

    Ala, Maureen; Gruidl, Jeremiah; Buddemeier, Brooke

    2015-09-30

    This document describes the development of the ROSS SKAs, the cross-mapping of the SKAs to the available training, identifies gaps in the SKA and training, and provides recommendations to address those gaps.

  7. Literature and Writing: A Conversation with Ramon Ross.

    ERIC Educational Resources Information Center

    Writing Teacher, 1989

    1989-01-01

    Interviews Dr. Ramon Ross of San Diego State University, an experienced author and teacher. Discusses the relationship between writing and literature, and suggests techniques for using the two in harmony. (SR)

  8. Literature and Writing: A Conversation with Ramon Ross.

    ERIC Educational Resources Information Center

    Writing Teacher, 1989

    1989-01-01

    Interviews Dr. Ramon Ross of San Diego State University, an experienced author and teacher. Discusses the relationship between writing and literature, and suggests techniques for using the two in harmony. (SR)

  9. 36 CFR 7.69 - Ross Lake National Recreation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.69 Ross Lake National Recreation Area... the U.S./Canadian border to the end of the road at East Landing. (3) Access and circulatory roads...

  10. 36 CFR 7.69 - Ross Lake National Recreation Area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.69 Ross Lake National Recreation Area... the U.S./Canadian border to the end of the road at East Landing. (3) Access and circulatory roads...

  11. 36 CFR 7.69 - Ross Lake National Recreation Area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.69 Ross Lake National Recreation Area... the U.S./Canadian border to the end of the road at East Landing. (3) Access and circulatory roads...

  12. 36 CFR 7.69 - Ross Lake National Recreation Area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.69 Ross Lake National Recreation Area... the U.S./Canadian border to the end of the road at East Landing. (3) Access and circulatory roads...

  13. 36 CFR 7.69 - Ross Lake National Recreation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.69 Ross Lake National Recreation Area... the U.S./Canadian border to the end of the road at East Landing. (3) Access and circulatory roads...

  14. STS-74 M.S. Jerry L. Ross suits up

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Spaceflight veteran Jerry L. Ross, Mission Specialist 2 on Shuttle Mission STS-74, is assisted by a suit technician as he finishes getting into his launch/entry suit in the Operations and Checkout Building. Ross and four fellow astronauts will depart shortly for Launch Pad 39A, where the Space Shuttle Atlantis awaits a second liftoff attempt during a seven-minute window scheduled to open at approximately 7:30 a.m. EST, Nov. 12.

  15. Circulation and melting beneath the ross ice shelf.

    PubMed

    Jacobs, S S; Gordon, A L; Ardai, J L

    1979-02-02

    Thermohaline observations in the water column beneath the Ross Ice Shelf and along its terminal face show significant vertical stratification, active horizontal circulation, and net melting at the ice shelf base. Heat is supplied by seawater that moves southward beneath the ice shelf from a central warm core and from a western region of high salinity. The near-freezing Ice Shelf Water produced flows northward into the Ross Sea.

  16. Western Ross Sea continental slope gravity currents

    NASA Astrophysics Data System (ADS)

    Gordon, Arnold L.; Orsi, Alejandro H.; Muench, Robin; Huber, Bruce A.; Zambianchi, Enrico; Visbeck, Martin

    2009-06-01

    Antarctic Bottom Water of the world ocean is derived from dense Shelf Water that is carried downslope by gravity currents at specific sites along the Antarctic margins. Data gathered by the AnSlope and CLIMA programs reveal the presence of energetic gravity currents that are formed over the western continental slope of the Ross Sea when High Salinity Shelf Water exits the shelf through Drygalski Trough. Joides Trough, immediately to the east, offers an additional escape route for less saline Shelf Water, while the Glomar Challenger Trough still farther east is a major pathway for export of the once supercooled low-salinity Ice Shelf Water that forms under the Ross Ice Shelf. The Drygalski Trough gravity currents increase in thickness from ˜100 to ˜400 m on proceeding downslope from ˜600 m (the shelf break) to 1200 m (upper slope) sea floor depth, while turning sharply to the west in response to the Coriolis force during their descent. The mean current pathway trends ˜35° downslope from isobaths. Benthic-layer current and thickness are correlated with the bottom water salinity, which exerts the primary control over the benthic-layer density. A 1-year time series of bottom-water current and hydrographic properties obtained on the slope near the 1000 m isobath indicates episodic pulses of Shelf Water export through Drygalski Trough. These cold (<-1 °C), salty (>34.75) pulses correlate with strong downslope bottom flow. Extreme examples occurred during austral summer/fall 2003, comprising concentrated High Salinity Shelf Water (-1.9 °C; 34.79) and approaching 1.5 m s -1 at descent angles as large as ˜60° relative to the isobaths. Such events were most common during November-May, consistent with a northward shift in position of the dense Shelf Water during austral summer. The coldest, saltiest bottom water was measured from mid-April to mid-May 2003. The summer/fall export of High Salinity Shelf Water observed in 2004 was less than that seen in 2003. This

  17. A study on the polynyas of the Ross Sea

    NASA Astrophysics Data System (ADS)

    Flocco, D.; Biggs, N. R. T.; Zambianchi, E.; Wadhams, P.

    2003-04-01

    The Ross Sea polynya is a complex oceanographic feature with a strong influence on the heat balances of the Ross Sea. The opening of the Ross Sea polynya depends on three main factors: the katabatic surges associated with the cyclogenesys events on the Siple coast, the katabatic flow down the glaciers in the Eastern Ross Sea and the katabatic winds blowing from the Transantarctic Mountains, which are turned aside by Ross Island (Bromwich et al., 1998). In this work, the polynya opening and closure in 1999 is studied. A flux model (Biggs et al. 2000) is applied to a few case study in order to describe the polynya behaviour. Heat fluxes and sea ice production will be evaluated by using bulk formulae. The meteorological input for the calculations are provided by the European Center for Medium-range Weather Forecasting. Sea ice concentration data will be used in order to validate the model. Daily ice concentration data were retrieved by using the Sea Lion algorithm to obtain maps of the polynya area with a spatial resolution of 12.5x12.5km2 (Kern and Heygster, 2001; Kern, 2001). This is achieved using the polarization difference of 85GHz brightness temperatures acquired by the Special Sensor Microwave/Imager (SSM/I). This study focuses on the Ross Sea Polynya, but nevertheless the Terra Nova Bay polynya case will be investigated.

  18. Odd cloud in the Ross Sea, Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On January 28, 2002, MODIS captured this image of an interesting cloud formation in the boundary waters between Antarctica's Ross Sea and the Southern Ocean. A dragon? A snake? A fish? No, but it is an interesting example of the atmospheric physics of convection. The 'eye' of this dragon-looking cloud is likely a small spot of convection, the process by which hot moist air rises up into the atmosphere, often producing big, fluffy clouds as moisture in the air condenses as rises into the colder parts of the atmosphere. A false color analysis that shows different kinds of clouds in different colors reveals that the eye is composed of ice crystals while the 'body' is a liquid water cloud. This suggests that the eye is higher up in the atmosphere than the body. The most likely explanation for the eye feature is that the warm, rising air mass had enough buoyancy to punch through the liquid water cloud. As a convective parcel of air rises into the atmosphere, it pushes the colder air that is higher up out of its way. That cold air spills down over the sides of the convective air mass, and in this case has cleared away part of the liquid cloud layer below in the process. This spilling over of cold air from higher up in the atmosphere is the reason why thunderstorms are often accompanied by a cool breeze. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  19. Odd cloud in the Ross Sea, Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On January 28, 2002, MODIS captured this image of an interesting cloud formation in the boundary waters between Antarctica's Ross Sea and the Southern Ocean. A dragon? A snake? A fish? No, but it is an interesting example of the atmospheric physics of convection. The 'eye' of this dragon-looking cloud is likely a small spot of convection, the process by which hot moist air rises up into the atmosphere, often producing big, fluffy clouds as moisture in the air condenses as rises into the colder parts of the atmosphere. A false color analysis that shows different kinds of clouds in different colors reveals that the eye is composed of ice crystals while the 'body' is a liquid water cloud. This suggests that the eye is higher up in the atmosphere than the body. The most likely explanation for the eye feature is that the warm, rising air mass had enough buoyancy to punch through the liquid water cloud. As a convective parcel of air rises into the atmosphere, it pushes the colder air that is higher up out of its way. That cold air spills down over the sides of the convective air mass, and in this case has cleared away part of the liquid cloud layer below in the process. This spilling over of cold air from higher up in the atmosphere is the reason why thunderstorms are often accompanied by a cool breeze. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  20. Seismicity in the vicinity of Ross Island, Antarctica

    NASA Astrophysics Data System (ADS)

    Rowe, C. A.; Kienle, J.

    1986-12-01

    Earthquakes in the Ross Sea, Antarctica, are of two types: volcanic, and those which appear to be of tectonic origin. Volcanic events in the vicinity of Ross Island are associated exclusively with Mount Erebus, Ross Island; this volcano erupts regularly, generating several earthquakes per day whose characteristics are quite distinct from non-volcanic events. These nonvolcanic earthquakes are recognizable by their distinct P- and S-wave arrivals, and a lack of the high frequency, often monochromatic character typical of Erebus events. One hundred fifty-seven tectonic microearthquakes (M < 2.0) were recorded in 1983 and 1984 by the ten station network on Ross Island; these events were located using the least-squares routine, HYPOELLIPSE. Of these events, 106 have RMS residual traveltime errors of less than or equal to 0.6 seconds; they are clustered in the vicinity of Ross Island, but are not restricted to it. There is a linear trend of epicenters cutting across the island and continuing northward. Most activity seems to center beneath Mount Terra Nova, between Mount Erebus and Mount Terror. Mean depth for events is 8.2 km; however, depths are rather evenly distributed over a range of 0 to 25 km. Modelling based on Bouger gravity anomalies and seismic refraction studies indicates a depth to the Moho of about 40 km beneath the continent, shallowing to 27 km beneath the Ross Sea. This 27 km depth is approximately equal to the lower limit of the tectonic seismicity detected by the Erebus network; hence, events are of crustal origin. These data suggest, with the rift-type geochemistry of Erebus' magma, that the Ross Sea is a site of active crustal extension and rifting.

  1. Glacial history of Prince Gustav Channel and James Ross Island

    NASA Astrophysics Data System (ADS)

    Glasser, N. F.; Davies, B. J.; Hambrey, M.; Carrivick, J.; Nyvlt, D.; Smellie, J.

    2012-12-01

    During the Last Glacial Maximum (LGM) in Antarctica, circa 18 cal. ka BP, ice draining from northeast Antarctic Peninsula and an ice dome over James Ross Island coalesced in Prince Gustav Channel. These glaciers formed a palaeo-ice stream flowing northwards and southwards to the shelf edge, resulting in an ice divide off northwest James Ross Island. However, this record is largely derived from marine sediment cores and swath bathymetry. The onshore interaction of Antarctic Peninsula-derived ice and an extended Mount Haddington Ice Cap on James Ross Island remains uncertain, and chronostratigraphy is poor, being largely based on radiocarbon dates, which are influenced by the large marine reservoir effect. A key issue is the age of the glacial incursion that deposited the granite erratics on Ulu Peninsula. Our hypothesis is that James Ross Island was initially inundated by a thick Antarctic Peninsula Ice Sheet, which deposited the inland and high-elevation erratic boulders on James Ross Island. During deglaciation, this ice sheet was subsequently drained by fast-flowing ice streams including the ice stream that developed in the Prince Gustav Channel. At this time the Antarctic Peninsula Ice Sheet ice was thinner and therefore only impinged on the coastal fringes of James Ross Island. We therefore anticipate that the inland and high-elevation granite boulders on basalt-rich glacial deposits will yield the age of pre-LGM ice advances of the Antarctic Peninsula Ice Sheet onto James Ross Island, and that the erratic boulders associated with glacial deposits enriched in Trinity Peninsula erratics at low-lying coastal sites will represent the age of the deglacial Prince Gustav Ice Stream.

  2. Radiological Operations Support Specialist (ROSS) Pilot Course Summary and Recommendations

    SciTech Connect

    Alai, M.; Askin, A.; Buddemeier, B.; Wogan, L.; Doshi, P.; Tai, L.

    2016-09-30

    In support of the Department of Homeland Security / Science and Technology Directorate’s (DHS/S&T) creation of a new position called the Radiological Operations Support Specialist (ROSS), Lawrence Livermore National Laboratory (LLNL) in Sub-task 1.1 and 1.2 has assisted in the development of the ROSS skills, knowledge, and abilities (SKAs); identified potentially relevant training; cross-mapped the training to the SKAs; and identified gaps in the training related to the SKAs, as well as their respective level of training knowledge - current versus desired. In the follow on task, Sub-task 1.3, a 5 day ROSS Pilot Training course was developed to fill the priority gaps identified in Sub-Task 1.2. Additionally, in Sub-Task 1.5, LLNL has performed a gap analysis of electronic tools, handbooks, and job-aides currently available to the ROSS and developed recommendations for additional and next generation tools to ensure the operational effectiveness of the ROSS position. This document summarizes the feedback received from the instructors and pilot course observers on what worked in the course and what could be improved as well as an assessment of the Pre- and Post-Test administered to the students.

  3. Physiochemical controls on phytoplankton distributions in the Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Liu, Xiao; Smith, Walker O.

    2012-06-01

    The continental shelf of the Ross Sea, Antarctica, is characterized by extreme seasonal and interannual changes in atmospheric and oceanographic processes, which result in distinct temporal patterns in phytoplankton biomass and assemblage composition. However, the environmental forcing of these variations remains uncertain, especially when a series of correlated variables are considered. Hydrological profiles, dissolved nutrients, particulate matter, and phytoplankton pigments were measured in the southern Ross Sea in austral spring and summer during four years (1996-97, 2003-04, 2004-05, and 2005-06), and a series of multivariate analyses were conducted to assess the causative mechanisms in the control of phytoplankton distributions in the Ross Sea. Our results demonstrate that the significant interannual, seasonal and spatial variability that occurs in the southern Ross Sea in hydrographic and chemical properties is highly correlated with the variability in phytoplankton distributions. Although multiple controlling mechanisms were suggested, mixed layer depths did not appear to be a dominant factor regulating phytoplankton biomass or composition; conversely, we found a significant role of water column temperature in structuring phytoplankton assemblage composition in the southern Ross Sea, in that cooler water strongly selects for Phaeocystis antarctica, which is a dominant control of carbon flux to depth, and thus of substantial biogeochemical importance.

  4. A composite semiresorbable armoured scaffold stabilizes pulmonary autograft after the Ross operation: Mr Ross's dream fulfilled.

    PubMed

    Nappi, Francesco; Spadaccio, Cristiano; Fraldi, Massimiliano; Montagnani, Stefania; Fouret, Pierre; Chachques, Juan Carlos; Acar, Christophe

    2016-01-01

    Use of resorbable external reinforcement of the pulmonary autograft during the Ross operation has been suggested, but the differential regional potential for dilation of the aorta, mainly regarding the neo-root and the neo-Valsalva sinuses, represents an unresolved issue. Auxetic materials could be useful in preventing dilation given their favorable mechanical properties. We designed a composite semiresorbable armoured bioprosthesis constituted by polydioxanone and expanded polytetrafluoroethylene and evaluated its effectiveness as a pulmonary autograft reinforcement device in an animal model of the Ross procedure. An experimental model of the Ross procedure was performed in 20 three-month-old growing lambs. The pulmonary autograft was alternatively nonreinforced (control group n = 10) or reinforced with composite bioprosthesis (reinforced group n = 10). Animals were followed up during growth for 6 months by angiography and echocardiography. Specific stainings for extracellular matrix and immunohistochemistry for metalloproteinase-9 were performed. Reference aortic diameter increased from 14 ± 1 mm to 19 ± 2 mm over 6 months of growth. In the control group, pulmonary autograft distension (28 ± 2 mm) was immediately noted, followed by aneurysm development at 6 months (40 ± 2 mm, P < .001 vs reference). In the reinforced group, an initial dilation to 18 ± 1 mm was detected and the final diameter was 27 ± 2 mm (42% increase). Two deaths due to pulmonary autograft rupture occurred in the control group. On histology, the control group showed medial disruption with connective fibrous replacement, whereas in the reinforced group compensatory intimal hyperplasia was present in the absence of intimal tears. The bioprosthesis promoted a positive matrix rearrangement process favoring neoarterialization and elastic remodeling as demonstrated on specific staining for elastin collagen and metalloproteinase-9. The device adapted and functionally compensated for the

  5. B-15 iceberg family in the Ross Sea, Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from September 17, 2000, shows the B15 family of icebergs that calved off the Ross Ice Shelf in March of 2000, at the end of the Antarctic summer melt season. The enormous bergs were locked up in winter sea ice before they could drift very far that first season, but at the onset of the winter thaw, soon after this image was acquired, the bergs began to drift. The large, southernmost berg is B-15, and it eventually drifted over toward Ross Island, seen at the bottom left of the image. The amazing shadow being cast on the ground south of Ross Island is from Mt. Erebus.

  6. Spring Phytoplankton Production in the Western Ross Sea

    NASA Astrophysics Data System (ADS)

    Arrigo, Kevin R.; McClain, Charles R.

    1994-10-01

    Coastal zone color scanner (CZCS) imagery of the western Ross Sea revealed the presence of an intense phytoplankton bloom covering >106,000 square kilometers in early December 1978. This bloom developed inside the Ross Sea polynya, within 2 weeks of initial polynya formation in late November. Primary productivity calculated from December imagery (3.9 grams of carbon per square meter per day) was up to four times the values measured during in situ studies in mid-January to February 1979. Inclusion of this early season production yields a spring-to-summer estimate of 141 to 171 grams of carbon per square meter, three to four times the values previously reported for the western Ross Sea.

  7. N-ROSS: The dynamics and control issues

    NASA Technical Reports Server (NTRS)

    Lindberg, Robert E.

    1986-01-01

    The Navy Remote Ocean Sensing System (N-ROSS) Dynamic Stability Study team concluded that the frozen April 1985 design was viable and contained no show stoppers, although it was also clear from the study results that the configuration required further optimization. While the frozen N-ROSS configuration used has since been superceded, and the vehicle is now under competitive procurement, several other results remain from the study that will have lasting value to the N-ROSS program. The importance of constructing an integrated simulation, to serve as a design and verification aid, has been clearly established. The two team approach to the study afforded the Navy a higher degree of confidence in the results than could have been accomplished by a single simulation, and the approach led to results that highlighted subtleties in the model and simulation development that surely would have been overlookded without the benefit of an independent companion simulation with which to compare it.

  8. Subsurface mapping of the Ross Island flexural basin, southwest Antarctica

    NASA Astrophysics Data System (ADS)

    Wenman, Christopher P.

    Ross Island is a post-Miocene (< 4.6 Ma) volcanic island located in the Ross Sea region of southwest Antarctica. This region of Antarctica borders the western edge of the West Antarctic Rift System, along the Transantarctic Mountain front. Marine and over-ice multi-channel seismic reflection surveys and borehole studies targeting the Ross Sea region over the last 30+ years have been used in this study to develop a seismic stratigraphic model of the development and evolution of the Ross Island flexural basin. Four key stratigraphic horizons were identified and mapped to fully capture the basin-fill, as well as strata lying above and below the flexural basin. From oldest to youngest these horizons are named RIB-m, RIM-g, RIM-b and RIB-r. Time structure, isochron and isochore maps were created for the horizons and the stratigraphic intervals they bound. The seismic stratigraphic record shows the Ross Island flexural moat formation post-dates the main tectonic subsidence phase within the Victoria Land Basin. The maps presented here are the first to fully illustrate the evolution of the Ross Island flexural basin. The maps highlight depositional patterns of two distinct periods of flexural subsidence and basin-filling superimposed on the older N-S trending Victoria Land Basin depocenter. Two units of flexural basin fill, Unit FFI between horizons RIM-g and RIM-b (the oldest flexural basin fill), and Unit FFII between horizons RIM-b and RIB-r (the youngest flexural basin fill) are associated with the two periods of flexural subsidence. Flexural moat subsidence and subsequent filling occurred episodically during periods of active volcanism on the island. Unit FFI is estimated to range from ca. 4 to 2 Ma, corresponding with formation of the Mt. Bird volcanic edifice on Ross Island. Unit FFII ranges in age from ca. 2 to 1 Ma, and is related to Mt. Terror, Mt. Erebus, and Hut Point Peninsula volcanism. The isochore maps suggest the depocenter of the flexural basin during

  9. STS-88 Mission Specialist Ross suits up for launch

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-88 Mission Specialist Jerry L. Ross (left) and astronaut Charles Precourt pose for a photo during suiting up activities in the Operations and Checkout Building. STS-88 will be the sixth spaceflight for Ross, who is scheduled to perform three spacewalks on the mission. He and the five other STS-88 crew members will depart shortly for Launch Pad 39A where the Space Shuttle Endeavour is poised for liftoff on the first U.S. mission dedicated to the assembly of the International Space Station.

  10. Science opportunities using the NASA scatterometer on N-ROSS

    NASA Technical Reports Server (NTRS)

    Freilich, M. H.

    1985-01-01

    The National Aeronautics and Space Administration scatterometer (NSCAT) is to be flown as part of the Navy Remote Ocean Sensing System (N-ROSS) scheduled for launch in 1989. The NSCAT will provide frequent accurate and high-resolution measurements of vector winds over the global oceans. NSCAT data will be applicable to a wide range of studies in oceanography, meteorology, and instrument science. The N-ROSS mission, is outlined, are described. The capabilities of the NSCAT flight instrument and an associated NASA research ground data-processing and distribution system, and representative oceanographic meteorological, and instrument science studies that may benefit from NSCAT data are surveyed.

  11. 76 FR 81962 - Final Environmental Impact Statement for General Management Plan, Ross Lake National Recreation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... of Ross Lake NRA, Goodell Creek, and Newhalem Creek. Climate change impacts and Ross Lake NRA's... evaluating the changes and impacts of the other three alternatives. The emphasis of the No Action Alternative... NATIONAL PARK SERVICE Final Environmental Impact Statement for General Management Plan, Ross Lake...

  12. 76 FR 22338 - Proposed Fort Ross-Seaview Viticultural Area; Comment Period Reopening

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-21

    ... Alcohol and Tobacco Tax and Trade Bureau 27 CFR Part 9 RIN 1513-AB44 Proposed Fort Ross-Seaview... the Fort Ross-Seaview viticultural area in western Sonoma County, California. Through this notice, TTB is soliciting comments on the establishment of the Fort Ross-Seaview viticultural area as proposed...

  13. Ross Ice Shelf airstream driven by polar vortex cyclone

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2012-07-01

    The powerful air and ocean currents that flow in and above the Southern Ocean, circling in the Southern Hemisphere's high latitudes, form a barrier to mixing between Antarctica and the rest of the planet. Particularly during the austral winter, strong westerly winds isolate the Antarctic continent from heat, energy, and mass exchange, bolstering the scale of the annual polar ozone depletion and driving the continent's record-breaking low temperatures. Pushing through this wall of high winds, the Ross Ice Shelf airstream (RAS) is responsible for a sizable amount of mass and energy exchange from the Antarctic inland areas to lower latitudes. Sitting due south of New Zealand, the roughly 470,000-square-kilometer Ross Ice Shelf is the continent's largest ice shelf and a hub of activity for Antarctic research. A highly variable lower atmospheric air current, RAS draws air from the inland Antarctic Plateau over the Ross Ice Shelf and past the Ross Sea. Drawing on modeled wind patterns for 2001-2005, Seefeldt and Cassano identify the primary drivers of RAS.

  14. Astronauts Jerry Ross and Sherwood Spring assemble ACCESS components

    NASA Image and Video Library

    1985-12-01

    Astronauts Jerry L. Ross (left) and Sherwood C. (Woody) Spring are photographed as they assemble pieces of the Experimental Assembly of Structures in Extravehicular Activities (EASE) device in the open payload bay. The Canadian-built remote manipulator system (RMS) arm (partially obscured in the right portion of the frame) is in position to allow television cameras to record the activity.

  15. John Ross--The Story of an American Indian.

    ERIC Educational Resources Information Center

    Harrell, Sara Gordon

    First elected Principal Chief of the Cherokee Nation in 1828, John Ross served his people with courage and honor through a difficult and tragic period in their history. Born in 1790, he grew up when the Cherokees' world was rapidly changing and treaties with federal and state governments ended in broken promises and the loss of Cherokee lands. He…

  16. STS-74 MS Jerry L. Ross in white room

    NASA Technical Reports Server (NTRS)

    1995-01-01

    At Launch Pad 39A, Mission Specialist Jerry L. Ross is nearly ready to enter the Space Shuttle Atlantis, scheduled for liftoff at about 7:30 a.m. EST, Nov. 12. Johnson Space Center Lockheed suit technician Ray Villalobos (left) is one member of the white room closeout crew that helps Shuttle crews into the orbiter.

  17. Ross Ice Shelf and the Queen Maude Mounains, Antarctica

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Part of the Ross Ice Shelf and the Queen Maude Mounains of Antarctica (55.5N, 178.0W) are in the background of this scene, oriented toward the south. Low stratocumulus clouds are predominant throughout most of the scene.

  18. STS-74 MS Jerry L. Ross in white room

    NASA Technical Reports Server (NTRS)

    1995-01-01

    At Launch Pad 39A, Mission Specialist Jerry L. Ross is nearly ready to enter the Space Shuttle Atlantis, scheduled for liftoff at about 7:30 a.m. EST, Nov. 12. Johnson Space Center Lockheed suit technician Ray Villalobos (left) is one member of the white room closeout crew that helps Shuttle crews into the orbiter.

  19. Abundances in the metal poor dwarf Ross 451

    NASA Technical Reports Server (NTRS)

    Spiesman, William J.

    1990-01-01

    High dispersion echelle spectra of the high velocity subdwarf Ross 451 (= G236-080) were obtained using the 4-m telescope at Kitt Peak. Initial abundance determinations for six elements are presented, using absolute oscillator strengths and metal-poor stellar-atmosphere models.

  20. Ross Ice Shelf and the Queen Maude Mounains, Antarctica

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Part of the Ross Ice Shelf and the Queen Maude Mounains of Antarctica (55.5N, 178.0W) are in the background of this scene, oriented toward the south. Low stratocumulus clouds are predominant throughout most of the scene.

  1. John Ross--The Story of an American Indian.

    ERIC Educational Resources Information Center

    Harrell, Sara Gordon

    First elected Principal Chief of the Cherokee Nation in 1828, John Ross served his people with courage and honor through a difficult and tragic period in their history. Born in 1790, he grew up when the Cherokees' world was rapidly changing and treaties with federal and state governments ended in broken promises and the loss of Cherokee lands. He…

  2. Tectonic and Geomporphic Overview of the Ross Embayment Extensional Province

    NASA Astrophysics Data System (ADS)

    Wilson, D. S.

    2016-12-01

    The Ross Embayment is one of the lowest-standing continental regions on Earth. In essentially all places where basement topography has been mapped, the morphology is horst and graben. Several authors have suggested that the low topography is recent, with the area having been an orogenic highland in the Cretaceous. The tectonic extension driving the transition from high topography to low topography may have been as much as 500 km, with stretching factors of 2-3 over wide areas. Timing of the extension is incompletely known, but may have spanned most of the interval from 100 to 25 Ma. An analogy between the Ross Embayment and the North American Basin and Range province has often been suggested, and the case for that analogy has been growing. North American orogenic topography was probably highest 50 Ma, and margin-normal extension has been of the order of 200 km, and is ongoing. The Transantarctic Mountains bordering the Ross Embayment may share elements of their formation with the Wasatch Mountains of Utah and other parts of the eastern boundary of the Basin and Range. Glacial erosion and deposition have played a huge role in the geomorphic history of the Ross Embayment. The source region for the major ice streams, now well below sea level even after accounting for removal of the present ice load, restores with confidence to above sea level in the Eocene after accounting for the effects of 2 km of erosion and of thermal subsidence. The scale of these topographic changes is large enough that they need to be considered in detailed simulations of past climates, especially the initiation of the Antarctic ice sheets. Under generous interpretations of early Cenozoic tectonic extension in the Ross Embayment, the Late Cretaceous ancestral Transantarctic Mountains may have been high enough to host short-lived ice caps inferred from global sea level and oxygen-isotope records.

  3. Measles virus glycoprotein-pseudotyped lentiviral vector-mediated gene transfer into quiescent lymphocytes requires binding to both SLAM and CD46 entry receptors.

    PubMed

    Frecha, Cecilia; Lévy, Camille; Costa, Caroline; Nègre, Didier; Amirache, Fouzia; Buckland, Robin; Russell, Steven J; Cosset, François-Loïc; Verhoeyen, Els

    2011-06-01

    Gene transfer into quiescent T and B cells is of importance for gene therapy and immunotherapy approaches to correct hematopoietic disorders. Previously, we generated lentiviral vectors (LVs) pseudotyped with the Edmonston measles virus (MV) hemagglutinin and fusion glycoproteins (Hgps and Fgps) (H/F-LVs), which, for the first time, allowed efficient transduction of quiescent human B and T cells. These target cells express both MV entry receptors used by the vaccinal Edmonston strain, CD46 and signaling lymphocyte activation molecule (SLAM). Interestingly, LVs pseudotyped with an MV Hgp, blind for the CD46 binding site, were completely inefficient for resting-lymphocyte transduction. Similarly, SLAM-blind H mutants that recognize only CD46 as the entry receptor did not allow stable LV transduction of resting T cells. The CD46-tropic LVs accomplished vector-cell binding, fusion, entry, and reverse transcription at levels similar to those achieved by the H/F-LVs, but efficient proviral integration did not occur. Our results indicate that both CD46 and SLAM binding sites need to be present in cis in the Hgp to allow successful stable transduction of quiescent lymphocytes. Moreover, the entry mechanism utilized appears to be crucial: efficient transduction was observed only when CD46 and SLAM were correctly engaged and an entry mechanism that strongly resembles macropinocytosis was triggered. Taken together, our results suggest that although vector entry can occur through the CD46 receptor, SLAM binding and subsequent signaling are also required for efficient LV transduction of quiescent lymphocytes to occur.

  4. Vesicular stomatitis virus glycoprotein- and Venezuelan equine encephalitis virus-derived glycoprotein-pseudotyped lentivirus vectors differentially transduce corneal endothelium, trabecular meshwork, and human photoreceptors.

    PubMed

    Lipinski, Daniel M; Barnard, Alun R; Charbel Issa, Peter; Singh, Mandeep S; De Silva, Samantha R; Trabalza, Antonio; Eleftheriadou, Ioanna; Ellison, Stuart M; Mazarakis, Nicholas D; MacLaren, Robert E

    2014-01-01

    The ability to deliver a large transgene efficiently to photoreceptors using viral vectors remains problematic and yet is critical for the future therapy of inherited retinal diseases such as Stargardt's and Usher's 1B. Herein, we examine the ocular tropism of a HIV-1-based lentivirus vector pseudotyped with Venezuelan equine encephalitis virus-derived glycoprotein (VEEV-G) after intraocular delivery to the posterior and anterior chambers of C57BL/6 wild-type mice. Reporter gene (EGFP) expression was evaluated using in vivo fluorescence imaging followed by postmortem immunohistochemistry and retinal function assessed by electroretinography. Intracameral administration of VEEV-G and vesicular stomatitis virus glycoprotein (VSV-G)-pseudotyped vectors resulted in robust transgene expression in the corneal endothelium and trabecular meshwork. After subretinal administration, onset of transgene expression was observed in the retinal pigment epithelium (RPE) 1 day postinjection with both VEEV-G and control VSV-G pseudotypes, but no significant photoreceptor transduction was apparent. Substantial degeneration of the outer nuclear layer was observed with VEEV-G-pseudotyped vector, which corresponded to ablation of retinal function. Subretinal administration of VSV-G was observed to result in significant suppression of electrophysiological function compared with buffer-injected and uninjected control eyes. Suppression of the c-wave amplitude, in addition to reduced RPE65 expression, indicated potential RPE dysfunction. Ex vivo tropism of VSV-G was assessed using organotypic culture of explanted retina harvested from wild-type mice and human patients undergoing retinal detachment surgery to examine the prevention of transduction by physical barriers and species differences in tropism.

  5. Ross syndrome: Unilateral hyperhidrosis, Adie's tonic pupils and diffuse areflexia.

    PubMed

    Yaşar, Sirin; Aslan, Canan; Serdar, Zehra Aşiran; Demirci, Gülşen Tükenmez; Tutkavul, Kemal; Babalik, Dilek

    2010-12-01

    Ross syndrome is a rare disorder first described in 1958 with partial autonomic dysfunction. It has three basic components including unilateral or bilateral segmental anhidrosis, Adie's tonic pupils and areflexia or hyporeflexia of deep tendon reflexes. The most disturbing symptom in the patients is segmental compensatory hyperhidrosis and often the hypohidrosis or anhidrosis is not even noticed. While the pathogenesis of Ross syndrome is unclear, degenerative changes or damage to the peripheral autonomic nerve system or dorsal root ganglia have been suggested as possible causes. About 50 cases have been reported, usually by neurologists and ophthalmologists, and less often by dermatologists. We present a 26-year-old patient who displayed the classic triad of this syndrome, emphasizing that the presenting complaint may be hyperhidrosis and that multidisciplinary evaluation in neurology and ophthalmology is essential. © The Authors • Journal compilation © Blackwell Verlag GmbH, Berlin.

  6. Condition of the Ross Ice Shelf derived from AVHRR imagery

    NASA Technical Reports Server (NTRS)

    Casassa, Gino

    1993-01-01

    Advanced Very High Resolution Radiometer (AVHRR) satellite imagery is combined with the Ross Ice Shelf Geophysical and Glaciological Survey (RIGGS) data to study recent changes on the Ross Ice Shelf. Flow stripes that appear on the AVHRR imagery agree with significant changes in ice flow that have occurred over the past 1,100 years on the ice shelf sector fed by East Antarctica. A large looping pattern of flow stripes that disagrees with RIGGS flow lines appears west of Crary Ice Rise, on the eastern part of the ice shelf. This looped pattern is interpreted as relict flow stripes related to past activity of a major ice stream of West Antarctica, which occurred about 800 years ago.

  7. Condition of the Ross Ice Shelf derived from AVHRR imagery

    NASA Technical Reports Server (NTRS)

    Casassa, Gino

    1993-01-01

    Advanced Very High Resolution Radiometer (AVHRR) satellite imagery is combined with the Ross Ice Shelf Geophysical and Glaciological Survey (RIGGS) data to study recent changes on the Ross Ice Shelf. Flow stripes that appear on the AVHRR imagery agree with significant changes in ice flow that have occurred over the past 1,100 years on the ice shelf sector fed by East Antarctica. A large looping pattern of flow stripes that disagrees with RIGGS flow lines appears west of Crary Ice Rise, on the eastern part of the ice shelf. This looped pattern is interpreted as relict flow stripes related to past activity of a major ice stream of West Antarctica, which occurred about 800 years ago.

  8. ROSS: An Object-Oriented Language for Constructing Simulations.

    DTIC Science & Technology

    1984-12-01

    W. Giarla, S. Narain, E. Cesar , and S. Turner, R-3158-AF, October 1984. Fast Concurrent Simulation Using the Time Warp Mechanism, Part I: Local Contru... Villanueva , and H. M. Markowitz, The Simscript H Pmoramming Language, Prentice-Hall, Englewood Cliffs, New Jersey, 1968. Klahr, P., J. Ellis, W. Giarla, S...Narain, E. Cesar , and S. Turner, TWIRL Tactical Warfare in the ROSS Lanuage, The Rand Corporation, R.3158-AF, October 1984. Klahr, P., and W. S

  9. Provenance of Ross Sea Till From Sand Petrography

    NASA Astrophysics Data System (ADS)

    Lederer, J. R.; Swope, R.; Licht, K. J.

    2002-12-01

    The 125-2000 micron fraction of till samples from cores retrieved beneath the Whillans Ice Stream and Ice Stream C in West Antarctica and samples collected proximal to four outlet glaciers in East Antarctica have distinct compositions. The sand fraction of East Antarctic till samples is dominantly composed of angular intermediate to mafic igneous lithic fragments, quartz-rich lithic fragments, rounded quartz grains, rounded carbonate lithic fragments, angular pyroxene grains, and rounded feldspar grains. The sand fraction of West Antarctic till is dominantly composed of rounded quartz grains, rounded feldspar grains, quartz-rich lithic fragments, and felsic igneous lithic fragments containing quartz, feldspar and phyllosillicates (biotite and chlorite). We also examined the 125-2000 micron fraction of several till samples from cores retrieved from the eastern Ross Sea. The samples are composed of (1) (25-40 %) rounded quartz grains; (2) (10-36 %) quartz-rich lithic fragments; (3) (8-20 %) quartzite fragments; (4) (5-15 %) felsic igneous lithic fragments containing quartz, feldspar, hornblende, and phyllosilicates (biotite and chlorite); (5) (5-10 %) intermediate igneous lithic fragments containing quartz, feldspar, pyroxene, and amphibole; (6) (<1 %) carbonate grains; and (7) (<1 %) feldspar grains. Compositional similarities in last glacial maximum till from the eastern Ross Sea and till collected from beneath ice streams in West Antarctica indicate the likelihood that eastern Ross Sea sediments were deposited by an advance of the West Antarctic Ice Sheet. Most notable are the compositional similarities in the quartz grain and quartz-rich sedimentary lithic fragment percentages, and felsic lithic fragment percentages and composition. Future work involves sampling numerous last glacial maximum till samples across the Ross Sea using sand petrography as a provenance tracer to determine paleo ice flow paths.

  10. Ross sea ice motion, area flux, and deformation

    NASA Technical Reports Server (NTRS)

    kwok, Ron

    2005-01-01

    The sea ice motion, area export, and deformation of the Ross Sea ice cover are examined with satellite passive microwave and RADARSAT observations. The record of high-resolution synthetic aperture radar (SAR) data, from 1998 and 2000, allows the estimation of the variability of ice deformation at the small scale (10 km) and to assess the quality of the longer record of passive microwave ice motion. Daily and subdaily deformation fields and RADARSAT imagery highlight the variability of motion and deformation in the Ross Sea. With the passive microwave ice motion, the area export at a flux gate positioned between Cape Adare and Land Bay is estimated. Between 1992 and 2003, a positive trend can be seen in the winter (March-November) ice area flux that has a mean of 990 x 103 km2 and ranges from a low of 600 x 103 km2 in 1992 to a peak of 1600 x 103 km2 in 2001. In the mean, the southern Ross Sea produces almost twice its own area of sea ice during the winter. Cross-gate sea level pressure (SLP) gradients explain 60% of the variance in the ice area flux. A positive trend in this gradient, from reanalysis products, suggests a 'spinup' of the Ross Sea Gyre over the past 12 yr. In both the NCEP-NCAR and ERA-40 surface pressure fields, longer-term trends in this gradient and mean SLP between 1979 and 2002 are explored along with positive anomalies in the monthly cross-gate SLP gradient associated with the positive phase of the Southern Hemisphere annular mode and the extrapolar Southern Oscillation.

  11. Astronaut Jerry Ross on RMS holds on to ACCESS device

    NASA Image and Video Library

    1985-12-01

    61B-102-022 (1 Dec 1985) --- Astronaut Jerry L. Ross, anchored to the foot restraint on the remote manipulator system (RMS), holds onto the tower-like Assembly Concept for Construction of Erectable Space Structures (ACCESS) device, as the Atlantis flies over white clouds and blue ocean waters. The frame was exposed with a negative-equipped camera held by Astronaut Sherwood C. Spring, who was also on the EVA-task.

  12. Rosse, 3rd Earl of [William Parsons, Lord Rosse, Lord Oxmantown] (1800-67) and Rosse, 4th Earl of [Laurence Parsons, Lord Rosse, Lord Oxmantown] (1840-1908)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Irish astronomer and landowner, the 3rd Lord Rosse was educated at Trinity College, Dublin and Oxford as a mathematician. He became interested in astronomy and made at the family castle in Birr a 36 in reflector with the same design as William Herschel's (see HERSCEL FAMILY). Mapped the Moon, and observed nebulae with the intent to resolve them into stars. He developed the technology at Birr Cast...

  13. Ross sea ice motion, area flux, and deformation

    NASA Technical Reports Server (NTRS)

    kwok, Ron

    2005-01-01

    The sea ice motion, area export, and deformation of the Ross Sea ice cover are examined with satellite passive microwave and RADARSAT observations. The record of high-resolution synthetic aperture radar (SAR) data, from 1998 and 2000, allows the estimation of the variability of ice deformation at the small scale (10 km) and to assess the quality of the longer record of passive microwave ice motion. Daily and subdaily deformation fields and RADARSAT imagery highlight the variability of motion and deformation in the Ross Sea. With the passive microwave ice motion, the area export at a flux gate positioned between Cape Adare and Land Bay is estimated. Between 1992 and 2003, a positive trend can be seen in the winter (March-November) ice area flux that has a mean of 990 x 103 km2 and ranges from a low of 600 x 103 km2 in 1992 to a peak of 1600 x 103 km2 in 2001. In the mean, the southern Ross Sea produces almost twice its own area of sea ice during the winter. Cross-gate sea level pressure (SLP) gradients explain 60% of the variance in the ice area flux. A positive trend in this gradient, from reanalysis products, suggests a 'spinup' of the Ross Sea Gyre over the past 12 yr. In both the NCEP-NCAR and ERA-40 surface pressure fields, longer-term trends in this gradient and mean SLP between 1979 and 2002 are explored along with positive anomalies in the monthly cross-gate SLP gradient associated with the positive phase of the Southern Hemisphere annular mode and the extrapolar Southern Oscillation.

  14. Trophic interactions within the Ross Sea continental shelf ecosystem.

    PubMed

    Smith, Walker O; Ainley, David G; Cattaneo-Vietti, Riccardo

    2007-01-29

    The continental shelf of the Ross Sea is one of the Antarctic's most intensively studied regions. We review the available data on the region's physical characteristics (currents and ice concentrations) and their spatial variations, as well as components of the neritic food web, including lower and middle levels (phytoplankton, zooplankton, krill, fishes), the upper trophic levels (seals, penguins, pelagic birds, whales) and benthic fauna. A hypothetical food web is presented. Biotic interactions, such as the role of Euphausia crystallorophias and Pleuragramma antarcticum as grazers of lower levels and food for higher trophic levels, are suggested as being critical. The neritic food web contrasts dramatically with others in the Antarctic that appear to be structured around the keystone species Euphausia superba. Similarly, we suggest that benthic-pelagic coupling is stronger in the Ross Sea than in most other Antarctic regions. We also highlight many of the unknowns within the food web, and discuss the impacts of a changing Ross Sea habitat on the ecosystem.

  15. Trophic interactions within the Ross Sea continental shelf ecosystem

    PubMed Central

    Smith, Walker O; Ainley, David G; Cattaneo-Vietti, Riccardo

    2006-01-01

    The continental shelf of the Ross Sea is one of the Antarctic's most intensively studied regions. We review the available data on the region's physical characteristics (currents and ice concentrations) and their spatial variations, as well as components of the neritic food web, including lower and middle levels (phytoplankton, zooplankton, krill, fishes), the upper trophic levels (seals, penguins, pelagic birds, whales) and benthic fauna. A hypothetical food web is presented. Biotic interactions, such as the role of Euphausia crystallorophias and Pleuragramma antarcticum as grazers of lower levels and food for higher trophic levels, are suggested as being critical. The neritic food web contrasts dramatically with others in the Antarctic that appear to be structured around the keystone species Euphausia superba. Similarly, we suggest that benthic–pelagic coupling is stronger in the Ross Sea than in most other Antarctic regions. We also highlight many of the unknowns within the food web, and discuss the impacts of a changing Ross Sea habitat on the ecosystem. PMID:17405209

  16. Qualification test of the Ross Double Planetary Mixer

    NASA Technical Reports Server (NTRS)

    Lueders, Kurt F.

    1993-01-01

    This test report describes the qualification test of the Ross Double Planetary Mixer used to mix room temperature vulcanized (RTV) silicone (Dow Corning 90-006-2) for the redesigned solid rocket motor (RSRM) nozzle joints. Testing was completed 18 June 1993 in the M-113A Nozzle Fabrication Facility at Thiokol Corporation, Space Operations, Brigham City, Utah. The Ross mixer provides better mixing and better control on temperature and humidity, resulting in better quality RTV and a longer usable pot life. The test began on 3 May 1993 and was stopped due to operator error during the tensile strength and elongation testing. Specimens were ruined without gathering any useful data. A 'no test' was declared, the problem was remedied, and the test was re-run with MSFC approval. The test was run and all pass/fail criteria were met, most with a considerable margin. The Ross Double Planetary Mixer met all certification objectives and is recommended for immediate use for mixing RTV silicone for RSRM nozzle joints.

  17. Qualification test of the Ross Double Planetary Mixer

    NASA Astrophysics Data System (ADS)

    Lueders, Kurt F.

    1993-07-01

    This test report describes the qualification test of the Ross Double Planetary Mixer used to mix room temperature vulcanized (RTV) silicone (Dow Corning 90-006-2) for the redesigned solid rocket motor (RSRM) nozzle joints. Testing was completed 18 June 1993 in the M-113A Nozzle Fabrication Facility at Thiokol Corporation, Space Operations, Brigham City, Utah. The Ross mixer provides better mixing and better control on temperature and humidity, resulting in better quality RTV and a longer usable pot life. The test began on 3 May 1993 and was stopped due to operator error during the tensile strength and elongation testing. Specimens were ruined without gathering any useful data. A 'no test' was declared, the problem was remedied, and the test was re-run with MSFC approval. The test was run and all pass/fail criteria were met, most with a considerable margin. The Ross Double Planetary Mixer met all certification objectives and is recommended for immediate use for mixing RTV silicone for RSRM nozzle joints.

  18. Ross Ice Shelf Polynya - Contribution to Antarctic Sea Ice Variability

    NASA Astrophysics Data System (ADS)

    Ward, J. M.; Raphael, M. N.

    2016-12-01

    The complexity of the Antarctic sea ice system is contributed to by the numerous sea ice generating polynyas which occur around the continental coast. The Ross Ice Shelf Polynya is the largest by far and has the highest ice production rates. It is commonly assumed that the relationship between the size of the open water area and sea ice generation is positive. This study uses NASA Team sea ice concentration (SIC) and a new and unique dataset of daily RISP area to establish and examine the temporal geographical reach of the sea ice generated within the RISP. The dataset spans the period 1987 - 2015 and represents the longest timeseries of this polynya to date. Initial analyses show that areal variability of the RISP has significant effects on the SIC in the Ross Sea sector. The relationship varies in sign and strength depending on the time of year. During the warm season, the relationship is strongly negative suggesting that a larger polynya is associated with lower SIC. During the cold season, the relationship is positive and stronger in some months than others. These new findings are discussed. This study sheds new light on the way in which the RISP interacts with the SIC in the Ross Sea and has potential for increasing our understanding of sea ice variability in that region.

  19. Note On The Ross Sea Shelf Water Downflow Processes (antarctica)

    NASA Astrophysics Data System (ADS)

    Bergamasco, A.; Defendi, V.; Spezie, G.; Budillon, G.; Carniel, S.

    In the framework of the CLIMA Project of the Italian National Program for Research in Antarctica, three different experimental data sets were acquired along the continental shelf break; two of them (in 1997 and 2001) close to Cape Adare, the 1998 one in the middle of the Ross Sea (i.e. 75 S, 177 W). The investigations were chosen in order to explore the downslope flow of the bottom waters produced in the Ross Sea, namely the High Salinity Shelf Water (HSSW, the densest water mass of the southern ocean coming from its formation site in the polynya region in Terra Nova bay), and the Ice Shelf Water (ISW, originated below the Ross Ice Shelf and outflowing northward). Both bottom waters spill over the shelf edge and mix with the Circumpolar Deep Water (CDW) contributing to the formation of the Antarctic Bottom Waters (AABW). Interpreting temperature, salinity and density maps in terms of cascading processes, both HSSW and ISW overflows are evidenced during, respectively, 1997 and 1998. During the 2001 acquisition there is no presence of HSSW along the shelf break, nevertheless distribution captures the evidence of a downslope flow process.

  20. The Hillary Canyon and the Iselin Bank (Eastern Ross Sea, Antarctica): Alongslope and Downslope Route For Ross Sea Bottom Water

    NASA Astrophysics Data System (ADS)

    De Santis, L.; Bergamasco, A.; Colizza, E.; Geletti, R.; Accaino, F.; Wardell, N.; Olivo, E.; Petronio, L.; Henrys, S. A.; Black, J.; Mckay, R. M.; Bohm, G.

    2015-12-01

    The modern seabed of the Antarctic continental slope generally does not show a rugged geomorphology. Channel systems incise the lower continental rise, but in most cases they are inherited features formed as channel-levee turbiditic systems during past, more temperate times. The Hillary Canyon cuts the eastern Ross Sea continental slope and rise, to the Southeast of the Iselin Bank, and is directly connected to the Glomar Challenger Trough on the continental shelf. Cold dense salty water forms today in the Ross Sea polynya, spreads below the Ross Ice Shelf, becomes supercooled, fills up the landward deepening Glomar Challenger Trough and then spills over the sill of the shelf edge and flows downslope, often along the Hillary Canyon, in a geostrophic way, deviated westwards by the Coriolis Force, but sometimes also with a cascading a-geostrophic behaviour. This supercold water signal was found on the continental slope down to 1200 m depth. The shape of this tongue of modified ISW, whose thickness reaches up to 100 m, is very narrow, suggesting that the overflow occurs in very localized areas along the slope. Here we combine seismic stratigraphy analysis of multichannel seismic reflection profiles, box and gravity cores in the Hillary Canyon and along the eastern flank of the Iselin Bank, with seabed bathymetry and numerical modelling of thevertical and spatial distribution of the water masses, in order to identify modern and past pathways of the Ross Sea Bottom Water current. The results of this work show that the Hillary Canyon and the sediment mounds that formed along its flanks have been active since early Miocene times. Sediment drift-moat features and sediment waves are indicative of strong Northwest bottom currents reworking the seabed sediments at different water depths along the slope, possibly since the late Miocene. These sediment drifts are some of the targets of the IODP proposal 751-full.

  1. Amphibian Seismological Studies in the Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Schmidt-Aursch, Mechita; Kuk Hong, Jong; Lee, Won Sang; Geissler, Wolfram; Yun, Sukyoung; Gohl, Karsten; Park, Yongcheol; Yoo, Hyun Jae

    2016-04-01

    The Antarctic Ross Sea is one of the key regions for polar research activities. Research stations from several countries located at the coast are the base for inland expeditions. Even in the austral summer, the Ross Sea is party covered with drifting ice fields; this requires an icebreaker for all marine explorations. Therefore, large geophysical surveys in the Ross Sea are difficult. But the area is of special interest for seismologists: The Terror Rift in the western Ross Sea is a prominent neotectonic structure of the West Antarctic Rift System (WARS). It is located near the coast in the Victoria Land Basin and extends parallel to the Transantarctic Mountains. The rifting processes and the accompanying active onshore volcanism lead to increased seismicity in the region. The annual waxing and waning of the sea-ice and the dynamics of the large Ross Ice Shelf and nearby glaciers generate additional seismic signals. Investigation on seismological activities associated with the WARS and the cryogenic signals simultaneously would give us an unprecedented opportunity to have a better understanding of the Evolution of the WARS (EWARS) and the rapid change in the cryospheric environment nearby. The Korea Polar Research Institute (KOPRI) and the Alfred-Wegener-Institut (AWI) have conducted a pilot study off the Korean Jang Bogo research station in the Terra Nova Bay by developing a collaborative research program (EWARS) since 2011 to explore seismicity and seismic noise in this region. Four broadband ocean-bottom seismometers (OBS) from the German DEPAS pool were deployed in January 2012 with the Korean research icebreaker RV Araon. Three instruments could successfully be recovered after 13 months, the fourth OBS was not accessible due to local sea-ice coverage. We have successfully completed a second recovery operation in January 2014. All stations recorded data of good quality, one station stopped after 8 months due to a recorder error. The OBS recovered in 2014

  2. Ross Ice Shelf Seismic Survey and Future Drilling Recommendation

    NASA Astrophysics Data System (ADS)

    van Haastrecht, Laurine; Ohneiser, Christian; Gorman, Andrew; Hulbe, Christina

    2016-04-01

    The Ross Ice Shelf (RIS) is one of three gateways through which change in the ocean can be propagated into the interior of West Antarctica. Both the geologic record and ice sheet models indicate that it has experienced widespread retreat under past warm climates. But inland of the continental shelf, there are limited data available to validate the models. Understanding what controls the rate at which the ice shelf will respond to future climate change is central to making useful climate projections. Determining the retreat rate at the end of the last glacial maximum is one part of this challenge. In November 2015, four lines of multi-channel seismic data, totalling over 45 km, were collected on the Ross Ice Shelf, approximately 300 km south of Ross Island using a thumper seismic source and a 96 channel snow streamer. The seismic survey was undertaken under the New Zealand Antarctic Research Institute (NZARI) funded Aotearoa New Zealand Ross Ice Shelf Programme to resolve bathymetric details and to image sea floor sediments under a proposed drilling site on the ice shelf, at about 80.7 S and 174 E. The thumper, a purpose-built, trailer mounted, weight-drop seismic source was towed behind a Hägglund tracked vehicle to image the bathymetry and sediments underneath the RIS. Seismic data collection on an ice shelf has unique challenges, in particular strong attenuation of the seismic energy by snow and firn, and complex multiple ray paths. The thumper, which consists of a heavy weight (250kg) that is dropped on a large, ski mounted steel plate, produced a consistent, repeatable higher energy signal when compared to sledge hammer source and allowed for a greater geographic coverage and lower environmental impact than an explosive source survey. Our survey revealed that the seafloor is smooth and that there may be up to 100 m of layered sediments beneath the seafloor and possibly deeper, more complex structures. A multiple generated by internally reflected seismic energy

  3. Unique manifestations of mixed-phase cloud microphysics over Ross Island and the Ross Ice Shelf, Antarctica

    NASA Astrophysics Data System (ADS)

    Scott, Ryan C.; Lubin, Dan

    2016-03-01

    Spaceborne radar and lidar observations from the CloudSat and CALIPSO satellites are used to compare seasonal variations in the microphysical and radiative properties of clouds over Ross Island, Antarctica, with two contrasting Arctic atmospheric observatories located in Barrow, Alaska, and Summit, Greenland. At Ross Island, downstream from recurrent intrusions of marine air over the West Antarctic Ice Sheet and eastern Ross Ice Shelf, clouds exhibit a tendency toward the greatest geometrical thickness and coldest temperatures in summer, the largest average ice water content, IWC, at low altitude during summer and autumn, the most abundant IWC at cold mixed-phase temperatures (-40°C

  4. High-resolution Body Wave Tomography of the Ross Sea Embayment, Antarctica

    NASA Astrophysics Data System (ADS)

    Nyblade, A.; White-Gaynor, A.; Wiens, D.; Aster, R. C.; Gerstoft, P.; Bromirski, P. D.; Stephen, R. A.; Winberry, J. P.; Huerta, A. D.; Anandakrishnan, S.; Wilson, T. J.

    2016-12-01

    The West Antarctic Rift System (WARS) remains the least understood continental rift system on the planet. The WARS is largely composed of the Ross Sea Embayment, which is overlain by the Ross Ice Shelf between Marie Byrd Land and the Transantarctic Mountains. Active volcanism on Ross Island continues to challenge our understanding of the seismically quiescent rift system. Previous regional-scale body wave tomographic investigations have identified areas of low seismic wave speed to about 200 km depth beneath Ross Island. However mantle structure under the Ross Sea Embayment away from Ross Island has not been previously well imaged. For this investigation we utilize teleseismic P waves recorded on the recently deployed RIS/DRIS network, which consists of 34 seismometers deployed across the Ross Ice Shelf, along with data from nearby POLENET stations and TAMSEIS stations. Relative P wave travel time residuals were obtained from 560 events using a multichannel cross correlation method, and have been inverted to obtain a preliminary model of the upper mantle. Initial results suggest that the low wave speed structure under Ross Island does not extend beneath the Ross Sea Embayment portion of the WARS.

  5. Downslope flow across the Ross Sea shelf break (Antarctica)

    NASA Astrophysics Data System (ADS)

    Bergamasco, A.; Budillon, G.; Carniel, S.; Defendi, V.; Meloni, R.; Paschini, E.; Sclavo, M.; Spezie, G.

    2003-12-01

    The analysis of some high-resolution hydrological data sets acquired during the 1997, 1998, 2001 and 2003 austral summers across the Ross Sea continental shelf break are here presented. The main focus of these cruises carried out in the framework of the Italian National Antarctic Program was the investigation of the downslope flow of the dense waters originated inside the Ross Sea. Such dense waters, flow near the bottom and, reaching the continental shelf break, ventilate the deep ocean. Two Antarctic continental shelf mechanisms can originate dense and deep waters. The former mechanism involves the formation, along the Victoria Land coasts, of a dense and saline water mass, the High Salinity Shelf Water (HSSW). The HSSW formation is linked to the rejection of salt into the water column as sea ice freezes, especially during winter, in the polynya areas, where the ice is continuously pushed offshore by the strong katabatic winds. The latter one is responsible of the formation of a supercold water mass, the Ice Shelf Water (ISW). The salt supplied by the HSSW recirculated below the Ross Ice Shelf, the latent heat of melting and the heat sink provided by the Ross Ice Shelf give rise to plumes of ISW, characterized by temperatures below the sea-surface freezing point. The dense shelf waters migrate to the continental shelf-break, spill over the shelf edge and descend the continental slope as a shelf-break gravity current, subject to friction and possibly enhanced by topographic channelling. Friction, in particular, breaks the constraint of potential vorticity conservation, counteracting the geostrophic tendency for along slope flow. The density-driven downslope motion or cascading entrains ambient water, namely the lower layer of the CDW, reaches a depth where density is the same and spreads off-slope. In fact, the cascading event is inhibited by friction without entrainment. The downslope processes are important for the ocean and climate system because they play a

  6. Positive mass balance of the Ross Ice Streams, West Antarctica.

    PubMed

    Joughin, Ian; Tulaczyk, Slawek

    2002-01-18

    We have used ice-flow velocity measurements from synthetic aperture radar to reassess the mass balance of the Ross Ice Streams, West Antarctica. We find strong evidence for ice-sheet growth (+26.8 gigatons per year), in contrast to earlier estimates indicating a mass deficit (-20.9 gigatons per year). Average thickening is equal to approximately 25% of the accumulation rate, with most of this growth occurring on Ice Stream C. Whillans Ice Stream, which was thought to have a significantly negative mass balance, is close to balance, reflecting its continuing slowdown. The overall positive mass balance may signal an end to the Holocene retreat of these ice streams.

  7. STS-110 M.S. Ross suits up for TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-110 Mission Specialist Jerry Ross relaxes during suit fit, which is part of Terminal Countdown Demonstration Test activities. The TCDT is held at KSC prior to each Space Shuttle flight to provide flight crews an opportunity to participate in simulated launch countdown activities. Scheduled for launch April 4, the 11-day mission will feature Shuttle Atlantis docking with the International Space Station (ISS) and delivering the S0 truss, the centerpiece-segment of the primary truss structure that will eventually extend over 300 feet.

  8. STS-88 Mission Specialists Currie and Ross inside Endeavour

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-88 Mission Specialists Nancy J. Currie, Ph.D., (back) and Jerry L. Ross (front) check over equipment inside orbiter Endeavour during Terminal Countdown Demonstration Activities (TCDT). The TCDT includes mission familiarization activities, emergency egress training, and the simulated main engine cut-off exercise. Mission STS-88 is targeted for launch on Dec. 3, 1998. It is the first U.S. flight for the assembly of the International Space Station and will carry the Unity connecting module. Unity will be mated with the already orbiting Russian-built Zarya control module. The 12-day mission includes three planned spacewalks to connect power, data and utility lines and install exterior equipment.

  9. STS-88 Mission Specialist Ross prepares to enter Endeavour

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-88 Mission Specialist Jerry L. Ross is assisted with his ascent and re-entry flight suit in the white room at Launch Pad 39A before entering Space Shuttle Endeavour for launch. During the nearly 12-day mission, the six-member crew will mate the first two elements of the International Space Station -- the already-orbiting Zarya control module with the Unity connecting module carried by Endeavour. He is making his sixth spaceflight and is one of two extravehicular activity crew members on this mission.

  10. Cryptoendolithic lichen and cyanobacterial communities of the Ross Desert, Antarctica.

    PubMed

    Friedmann, E I; Hua, M; Ocampo-Friedmann, R

    1988-01-01

    Cryptoendolithic microbial communities in the Ross Desert (McMurdo Dry Valleys) are characterized on the basis of photosynthetic microorganisms and fungi. Two eukaryotic communities (the lichen-dominated and Hemichloris communities) and three cyanobacterial communities (the red Gloeocapsa, Hormathonema-Gloeocapsa, and Chroococcidiopsis communities) are described. Eleven coccoid, one pleurocapsoid, and five filamentous cyanobacteria occurring in these communities are characterized and illustrated. The moisture grade of the rock substrate seems to affect pH, formation of primary iron stain, and the distribution of microbial communities.

  11. Cryptoendolithic lichen and cyanobacterial communities of the Ross Desert, Antarctica

    NASA Technical Reports Server (NTRS)

    Friedmann, E. I.; Hua, M.; Ocampo-Friedmann, R.

    1988-01-01

    Cryptoendolithic microbial communities in the Ross Desert (McMurdo Dry Valleys) are characterized on the basis of photosynthetic microorganisms and fungi. Two eukaryotic communities (the lichen-dominated and Hemichloris communities) and three cyanobacterial communities (the red Gloeocapsa, Hormathonema-Gloeocapsa, and Chroococcidiopsis communities) are described. Eleven coccoid, one pleurocapsoid, and five filamentous cyanobacteria occurring in these communities are characterized and illustrated. The moisture grade of the rock substrate seems to affect pH, formation of primary iron stain, and the distribution of microbial communities.

  12. The Era of Newton, Herschel and Lord Rosse

    NASA Astrophysics Data System (ADS)

    Bennett, Jim

    2009-08-01

    In the eighteenth century England was dominant in building telescopes and instrumentation. This paper describes the contributions of the most important opticians and telescope builders, from Newton’s Opticks and the telescope design that bears his name, through various instrument makers who constructed ‘popular’ telescopes and published descriptions of mirror grinding (Smith, the Dollonds and their patent on achromatic lenses), to Herschel, who refined the description of his polishing procedures, and Lord Rosse, who attempted to communicate his through publication. The narrative of theory, practice and communication takes unexpected turns.

  13. Ultraviolet spectrum synthesis of the helium white dwarf Ross 640

    NASA Technical Reports Server (NTRS)

    Cottrell, P. L.; Greenstein, J. L.

    1980-01-01

    The UV spectrum of the He-rich white dwarf Ross 640 was used to derive Mg, Si, and Fe abundances by a spectrum synthesis technique. The values obtained were: Mg/He = 6.8 x 10 to the -8th; Si/He = 3.2 x 10 to the -8th; Ca/He = 7.6 x 10 to the -10th; and Fe/He = 2.0 x 10 to the -9th. The abundances indicate the operation of diffusion processes within a helium-rich atmosphere, provided some mechanism exists to deposit metals in the observable layers.

  14. Cryptoendolithic lichen and cyanobacterial communities of the Ross Desert, Antarctica

    NASA Technical Reports Server (NTRS)

    Friedmann, E. I.; Hua, M.; Ocampo-Friedmann, R.

    1988-01-01

    Cryptoendolithic microbial communities in the Ross Desert (McMurdo Dry Valleys) are characterized on the basis of photosynthetic microorganisms and fungi. Two eukaryotic communities (the lichen-dominated and Hemichloris communities) and three cyanobacterial communities (the red Gloeocapsa, Hormathonema-Gloeocapsa, and Chroococcidiopsis communities) are described. Eleven coccoid, one pleurocapsoid, and five filamentous cyanobacteria occurring in these communities are characterized and illustrated. The moisture grade of the rock substrate seems to affect pH, formation of primary iron stain, and the distribution of microbial communities.

  15. Frank Elmore Ross and His Variable Star Discoveries

    NASA Astrophysics Data System (ADS)

    Osborn, W.

    2012-06-01

    Frank Ross (1874-1960) was a talented astronomer that excelled in such diverse fields as computational astronomy, optical instrument design, and astrophotography. His career and astronomical contributions are briefly summarized. One contribution was finding 379 probable new variable stars. Most of these variables are poorly studied, and for a number the identifications are still uncertain and the variability not yet confirmed more than eighty years after publication. Ross’s original observing cards and plates are being used to re-examine the stars and resolve the problem cases. Follow-up work on a few stars has yielded interesting results. This work is illustrated with one example.

  16. 75 FR 32802 - Certificate of Alternative Compliance for the Offshore Supply Vessel ROSS CANDIES

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-09

    ... SECURITY Coast Guard Certificate of Alternative Compliance for the Offshore Supply Vessel ROSS CANDIES... Alternative Compliance was issued for the offshore supply vessel ROSS CANDIES as required by 33 U.S.C. 1605(c... CANDIES, O.N. 1222260. Full compliance with 72 COLREGS ] would hinder the vessel's ability to maneuver...

  17. Does temperature structure phytoplankton community composition in the Ross Sea, Antarctica?

    EPA Science Inventory

    The Ross Sea polynya experiences one of the largest phytoplankton blooms in the Southern Ocean. Energy flow potential within the Ross Sea food web is primarily set by diatoms and prymnesiophytes, the latter dominated by Phaeocystis antarctica. We investigated physical, chemical,...

  18. 75 FR 69432 - Ross Bachofer v. Calpine Corporation; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Ross Bachofer v. Calpine Corporation; Notice of Complaint November 4, 2010..., 18 CFR 385.206 and section 206 of the Federal Power Act, 16 U.S.C. 2824c, Ross Bachofer...

  19. Critiquing Research Methodology: Comments on Broader Concerns about Complex Statistical Studies. A Response to Ross

    ERIC Educational Resources Information Center

    Stapleton, Paul

    2006-01-01

    Steven Ross's (2005) recent paper empirically measuring the efficacy of formative assessment compared to the summative variety found that the former produced positive effects on some aspects of language learning. In this critique, it is contended that Ross's study is flawed because his two groups of learners, one receiving summative assessment and…

  20. 77 FR 30320 - General Management Plan/Environmental Impact Statement, Ross Lake National Recreation Area, North...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR National Park Service General Management Plan/Environmental Impact Statement, Ross Lake National Recreation... the Final Environmental Impact Statement for the new General Management Plan (GMP) for Ross...

  1. Against Raising Hope of Raising the Dead: Contra Moody and Kubler-Ross.

    ERIC Educational Resources Information Center

    Vicchio, Stephen J.; And Others

    1979-01-01

    Kubler-Ross and Moody have made assertions about survival after death. They argued that the subjects were not dead, but in the process of dying. An alternative explanation to this "glimpse of the afterlife" approach is offered. Other theological objections are raised to the Moody/Kubler-Ross approach. (Author)

  2. Giving to Excellence: Generating Philanthropic Support for UK Higher Education. Ross-CASE Report 2016

    ERIC Educational Resources Information Center

    Jain, Yashraj

    2016-01-01

    This report presents findings from the 2016 Ross-CASE Survey of Philanthropic Giving to Universities in UK. The project was conducted by CASE Europe and funded by HEFCE and the Ross-Group. This year's survey comes at a time of great change for the UK charity sector. The historical trend data of previous surveys will be invaluable in helping…

  3. Against Raising Hope of Raising the Dead: Contra Moody and Kubler-Ross.

    ERIC Educational Resources Information Center

    Vicchio, Stephen J.; And Others

    1979-01-01

    Kubler-Ross and Moody have made assertions about survival after death. They argued that the subjects were not dead, but in the process of dying. An alternative explanation to this "glimpse of the afterlife" approach is offered. Other theological objections are raised to the Moody/Kubler-Ross approach. (Author)

  4. Response to Ross's "Commentary: Problems with the sexual disorders sections of DSM-5".

    PubMed

    Miccio-Fonseca, L C

    2015-01-01

    The recent commentary by Ross (2015) addresses concerns regarding the newly created Paraphilic Disorders section of the Diagnostic and Statistical Manual of Mental Disorders, fifth edition, and "inconsistencies." The author's statements reflect notable confusion regarding issues related to human sexuality and the categories thereof in the DSM-5 (e.g., gender dysphoria and pedophilic disorder). This is a response to Ross's commentary.

  5. The Re-construction of the 6-foot Rosse Telescope of Ireland

    NASA Astrophysics Data System (ADS)

    Tubridy, Michael

    An article describing the reconstruction and restoration efforts by Michael Tubridy, the engineer of the project, of the Lord Rosse Leviathan of Parsonstown, a 6-foot telescope, and the first to reveal spiral structure in galaxies, and a brief biography on the third Earl of Rosse, William Parsons.

  6. Does temperature structure phytoplankton community composition in the Ross Sea, Antarctica?

    EPA Science Inventory

    The Ross Sea polynya experiences one of the largest phytoplankton blooms in the Southern Ocean. Energy flow potential within the Ross Sea food web is primarily set by diatoms and prymnesiophytes, the latter dominated by Phaeocystis antarctica. We investigated physical, chemical,...

  7. The Oceanography and Ecology of the Ross Sea

    NASA Astrophysics Data System (ADS)

    Smith, Walker O.; Ainley, David G.; Arrigo, Kevin R.; Dinniman, Michael S.

    2014-01-01

    The continental shelf of the Ross Sea exhibits substantial variations in physical forcing, ice cover, and biological processes on a variety of time and space scales. Its circulation is characterized by advective inputs from the east and exchanges with off-shelf regions via the troughs along the northern portions. Phytoplankton biomass is greater there than anywhere else in the Antarctic, although nitrate is rarely reduced to levels below 10 μmol L-1. Overall growth is regulated by irradiance (via ice at the surface and by the depths of the mixed layers) and iron concentrations. Apex predators reach exceptional abundances, and the world's largest colonies of Adélie and emperor penguins are found there. Krill are represented by two species (Euphausia superba near the shelf break and Euphausia crystallorophias throughout the continental shelf region). Equally important and poorly known is the Antarctic silverfish (Pleuragramma antarcticum), which is also consumed by most upper-trophic-level predators. Future changes in the Ross Sea environment will have profound and unpredictable effects on the food web.

  8. Seasonal and diurnal calling patterns of Ross and leopards

    NASA Astrophysics Data System (ADS)

    Rogers, Tracey L.; Rowney, Gayle A.; Ciaglia, Michaela B.; Cato, Douglas H.

    2005-09-01

    The temporal calling patterns of two Antarctic pack ice seals, the leopard and Ross seal, were examined. This included seasonal onset and decline of calling (coinciding with their breeding season) as well as diurnal changes. Understanding of calling behavior has important implications for acoustic surveying, since this allows the number of calls to be related to an index of the number of animals present and to estimate abundance. The monthly changes in diurnal calling and haul-out patterns (measured via satellite telemetry) were compared. Underwater acoustic recordings were made between 14 October 2003 and 10 January 2004 off Mawson, Eastern Antarctica (660 44.243S and 690 48.748E). Recordings were made using an Acoustics Recording Package (ARP by Dr. John Hildebrand, Scripps Institute of Oceanography, La Jolla, CA) which is designed to sit on the seafloor and passively record acoustic signals. The package was deployed at a depth of 1320.7 m. The sampling rate was 500 Hz and the effective bandwidth from 10 to 250 Hz, covering the bandwidth of only the low-frequency calls of the Ross and leopard seal.

  9. A Study of the Low Mass Binary Star Ross 614

    NASA Astrophysics Data System (ADS)

    Gatewood, G.; Han, I.; Tangren, W.

    2001-12-01

    We have combined photograph, MAP, interferometric, and spectroscopic data to determine the orbital characteristics and masses of the Ross 614 binary star system. Attention was first drawn to the star by Frank E. Ross (1927, AJ 37, 193) who noticed its high proper motion in a comparison of new plates with those taken at the Yerkes Observatory by E.E. Barnard. The Binary nature of the star was recognized from accelerations in the star's proper motion (D. Reuyl 1936, AJ 55, 236) and the mass of the companion was first estimated by combining measurements of McCormick and Sproul plates with a separation measured by Walter Baade at the Hale 5-m reflector (S.L. Lippincott 1955, AJ 60, 379). In her paper Lippincott notes the companion's significance as defining the lower end of the observational main sequence. Fifty six years later the star still holds that honor. With a wealth of new data spanning more than 3 additional orbits, we find her value of 0.08 solar masses to be within our error of our value.

  10. The oceanography and ecology of the Ross Sea.

    PubMed

    Smith, Walker O; Ainley, David G; Arrigo, Kevin R; Dinniman, Michael S

    2014-01-01

    The continental shelf of the Ross Sea exhibits substantial variations in physical forcing, ice cover, and biological processes on a variety of time and space scales. Its circulation is characterized by advective inputs from the east and exchanges with off-shelf regions via the troughs along the northern portions. Phytoplankton biomass is greater there than anywhere else in the Antarctic, although nitrate is rarely reduced to levels below 10 μmol L(-1). Overall growth is regulated by irradiance (via ice at the surface and by the depths of the mixed layers) and iron concentrations. Apex predators reach exceptional abundances, and the world's largest colonies of Adélie and emperor penguins are found there. Krill are represented by two species (Euphausia superba near the shelf break and Euphausia crystallorophias throughout the continental shelf region). Equally important and poorly known is the Antarctic silverfish (Pleuragramma antarcticum), which is also consumed by most upper-trophic-level predators. Future changes in the Ross Sea environment will have profound and unpredictable effects on the food web.

  11. Decadal trends in air-sea CO2 exchange in the Ross Sea (Antarctica)

    NASA Astrophysics Data System (ADS)

    Tagliabue, Alessandro; Arrigo, Kevin R.

    2016-05-01

    Highly productive Antarctic shelf systems, like the Ross Sea, play important roles in regional carbon budgets, but the drivers of local variations are poorly quantified. We assess the variability in the Ross Sea carbon cycle using a regional physical-biogeochemical model. Regionally, total partial pressure of CO2 (pCO2) increases are largely controlled by the biological pump and broadly similar to those in the offshore Southern Ocean. However, this masks substantial local variability within the Ross Sea, where interannual fluctuations in total pCO2 are driven by the biological pump and alkalinity, whereas those for anthropogenic pCO2 are related to physical processes. Overall, the high degree of spatial variability in the Ross Sea carbon cycle causes extremes in aragonite saturation that can be as large as long-term trends. Therefore, Antarctic shelf polynya systems like the Ross Sea will be strongly affected by local processes in addition to larger-scale phenomena.

  12. Department management of the Ross Aviation, Inc. , contract aircraft major spare parts inventory, Albuquerque, New Mexico

    SciTech Connect

    Not Available

    1991-07-26

    The purpose of this audit was to determine whether the Department of Energy's (Department) management of its contract with Ross Aviation, Inc. (Ross) provided reasonable assurance that the inventory of aircraft major spare parts at Ross was economical and efficient. The audit disclosed that approximately $447,000 (acquisition and interest carrying costs) of low-use major spare parts was excessive. Internal control deficiencies which fostered the excessive inventory included: (1) Ross had set stock levels without considering such factors as consumption or projected needs; and (2) the Department had not reviewed inventory quantities when appraising Ross' property management. The Albuquerque Operations Office (AL) agreed to take the corrective actions recommended in the report.

  13. Past ice-sheet behaviour: retreat scenarios and changing controls in the Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Halberstadt, Anna Ruth W.; Simkins, Lauren M.; Greenwood, Sarah L.; Anderson, John B.

    2016-05-01

    Studying the history of ice-sheet behaviour in the Ross Sea, Antarctica's largest drainage basin can improve our understanding of patterns and controls on marine-based ice-sheet dynamics and provide constraints for numerical ice-sheet models. Newly collected high-resolution multibeam bathymetry data, combined with two decades of legacy multibeam and seismic data, are used to map glacial landforms and reconstruct palaeo ice-sheet drainage. During the Last Glacial Maximum, grounded ice reached the continental shelf edge in the eastern but not western Ross Sea. Recessional geomorphic features in the western Ross Sea indicate virtually continuous back-stepping of the ice-sheet grounding line. In the eastern Ross Sea, well-preserved linear features and a lack of small-scale recessional landforms signify rapid lift-off of grounded ice from the bed. Physiography exerted a first-order control on regional ice behaviour, while sea floor geology played an important subsidiary role. Previously published deglacial scenarios for Ross Sea are based on low-spatial-resolution marine data or terrestrial observations; however, this study uses high-resolution basin-wide geomorphology to constrain grounding-line retreat on the continental shelf. Our analysis of retreat patterns suggests that (1) retreat from the western Ross Sea was complex due to strong physiographic controls on ice-sheet drainage; (2) retreat was asynchronous across the Ross Sea and between troughs; (3) the eastern Ross Sea largely deglaciated prior to the western Ross Sea following the formation of a large grounding-line embayment over Whales Deep; and (4) our glacial geomorphic reconstruction converges with recent numerical models that call for significant and complex East Antarctic ice sheet and West Antarctic ice sheet contributions to the ice flow in the Ross Sea.

  14. Regional seismic stratigraphic correlations of the Ross Sea: Implications for the tectonic history of the West Antarctic Rift System

    USGS Publications Warehouse

    Decesari, Robert C.; Sorlien, Christopher C.; Luyendyk, Bruce P.; Wilson, Douglas S.; Bartek, Louis; Diebold, John; Hopkins, Sarah E.

    2007-01-01

    Using existing and new seismic reflection data, new and updated correlations of late Oligocene-early Miocene RSS-2 strata were made between the southern parts of Ross Sea basins. Previous studies documented Cretaceous extension across much of Ross Sea. We interpret that Cenozoic extension also occurred across Ross Sea. Subsidence during and following this extension deepened existing basins and may have initiated basins in the west, subsiding ridges between basins below sea level during the late Oligocene. Pre-Oligocene strata record cessation of L. Cretaceous extension in easternmost Ross Sea. Successively younger Cenozoic extension occurred from east to west across the rest of Ross Sea.

  15. Late Wisconsin and early holocene glacial history, inner Ross Embayment, Antarctica

    NASA Technical Reports Server (NTRS)

    Denton, George H.; Bockheim, James G.; Wilson, Scott C.; Stuiver, Minze

    1991-01-01

    Lateral drift sheets of outlet glaciers that pass through the Transantarctic Mountains constrain past changes of the huge Ross ice drainage system of the Antarctic Ice Sheet. Drift stratigraphy suggests correlation of Reedy III (Reedy Glacier), Beardmore, Britannia (Hatherton/Darwin Glaciers), Ross Sea (McMurdo Sound), and younger (Terra Nova Bay) drifts; radiocarbon dates place the outer limits of Ross Sea drift in late Wisconsin time at 24,000 to 13,000 yr B.P. Outlet glacier profiles from these drifts constrain late Wisconsin ice sheet surface elevations. Within these constraint, two extreme late Wisconsin reconstructions are given of the Ross ice drainage system. Both show little elevation change of the polar plateau coincident with extensive ice shelf grounding along the inner Ross Embayment. However, in the central Ross Embayment, one reconstruction shows floating shelf ice, where as the other shows a grounded ice sheet. Massive late Wisconsin/Holocene recession of grounded ice from the western Ross Embayment, which was underway at 13,040 yr B.P. and completed by 6600 to 6020 yr B.P., was accompanied by little change in plateau ice levels inland of the Transantarctic Mountains.

  16. Variability and Trends in Sea Ice Extent and Ice Production in the Ross Sea

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino; Kwok, Ronald; Martin, Seelye; Gordon, Arnold L.

    2011-01-01

    Salt release during sea ice formation in the Ross Sea coastal regions is regarded as a primary forcing for the regional generation of Antarctic Bottom Water. Passive microwave data from November 1978 through 2008 are used to examine the detailed seasonal and interannual characteristics of the sea ice cover of the Ross Sea and the adjacent Bellingshausen and Amundsen seas. For this period the sea ice extent in the Ross Sea shows the greatest increase of all the Antarctic seas. Variability in the ice cover in these regions is linked to changes in the Southern Annular Mode and secondarily to the Antarctic Circumpolar Wave. Over the Ross Sea shelf, analysis of sea ice drift data from 1992 to 2008 yields a positive rate of increase in the net ice export of about 30,000 sq km/yr. For a characteristic ice thickness of 0.6 m, this yields a volume transport of about 20 cu km/yr, which is almost identical, within error bars, to our estimate of the trend in ice production. The increase in brine rejection in the Ross Shelf Polynya associated with the estimated increase with the ice production, however, is not consistent with the reported Ross Sea salinity decrease. The locally generated sea ice enhancement of Ross Sea salinity may be offset by an increase of relatively low salinity of the water advected into the region from the Amundsen Sea, a consequence of increased precipitation and regional glacial ice melt.

  17. Variability and Trends in Sea Ice Extent and Ice Production in the Ross Sea

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino; Kwok, Ronald; Martin, Seelye; Gordon, Arnold L.

    2011-01-01

    Salt release during sea ice formation in the Ross Sea coastal regions is regarded as a primary forcing for the regional generation of Antarctic Bottom Water. Passive microwave data from November 1978 through 2008 are used to examine the detailed seasonal and interannual characteristics of the sea ice cover of the Ross Sea and the adjacent Bellingshausen and Amundsen seas. For this period the sea ice extent in the Ross Sea shows the greatest increase of all the Antarctic seas. Variability in the ice cover in these regions is linked to changes in the Southern Annular Mode and secondarily to the Antarctic Circumpolar Wave. Over the Ross Sea shelf, analysis of sea ice drift data from 1992 to 2008 yields a positive rate of increase in the net ice export of about 30,000 sq km/yr. For a characteristic ice thickness of 0.6 m, this yields a volume transport of about 20 cu km/yr, which is almost identical, within error bars, to our estimate of the trend in ice production. The increase in brine rejection in the Ross Shelf Polynya associated with the estimated increase with the ice production, however, is not consistent with the reported Ross Sea salinity decrease. The locally generated sea ice enhancement of Ross Sea salinity may be offset by an increase of relatively low salinity of the water advected into the region from the Amundsen Sea, a consequence of increased precipitation and regional glacial ice melt.

  18. Late Wisconsin and early holocene glacial history, inner Ross Embayment, Antarctica

    NASA Astrophysics Data System (ADS)

    Denton, George H.; Bockheim, James G.; Wilson, Scott C.; Stuiver, Minze

    1991-05-01

    Lateral drift sheets of outlet glaciers that pass through the Transantarctic Mountains constrain past changes of the huge Ross ice drainage system of the Antarctic Ice Sheet. Drift stratigraphy suggests correlation of Reedy III (Reedy Glacier), Beardmore, Britannia (Hatherton/Darwin Glaciers), Ross Sea (McMurdo Sound), and younger (Terra Nova Bay) drifts; radiocarbon dates place the outer limits of Ross Sea drift in late Wisconsin time at 24,000 to 13,000 yr B.P. Outlet glacier profiles from these drifts constrain late Wisconsin ice sheet surface elevations. Within these constraint, two extreme late Wisconsin reconstructions are given of the Ross ice drainage system. Both show little elevation change of the polar plateau coincident with extensive ice shelf grounding along the inner Ross Embayment. However, in the central Ross Embayment, one reconstruction shows floating shelf ice, where as the other shows a grounded ice sheet. Massive late Wisconsin/Holocene recession of grounded ice from the western Ross Embayment, which was underway at 13,040 yr B.P. and completed by 6600 to 6020 yr B.P., was accompanied by little change in plateau ice levels inland of the Transantarctic Mountains.

  19. Post-LGM Retreat History in Ross Sea Reflects Changing Controls on Marine Ice Sheet Behavior

    NASA Astrophysics Data System (ADS)

    Halberstadt, A. R.; Simkins, L. M.; Anderson, J. B.; Prothro, L. O.; Demet, B. P.; Greenwood, S. L.; Yokoyama, Y.

    2016-12-01

    Newly collected high-resolution multibeam swath bathymetry data and sediment cores, combined with two decades of legacy multibeam and seismic data, are used to map glacial landforms, reconstruct paleodrainage and study patterns, timing, and controls on marine-based ice-sheet dynamics in Antarctica's largest drainage basin, the Ross Sea. This paleodrainage reconstruction independently validates recent numerical models that call for significant and dynamic East Antarctic Ice Sheet and West Antarctic Ice Sheet contributions to ice flow in the Ross Sea. Last Glacial Maximum grounded ice reached the continental shelf edge in the eastern but not western Ross Sea. Recessional geomorphic features in the western Ross Sea indicate frequent, small scale grounding line retreat from the outer shelf following an episode of ice shelf collapse. In contrast, well-preserved linear features and large, isolated grounding zone wedges record large scale (tens of kilometers) step-wise grounding line retreat in eastern Ross Sea. Physiography exerted a first-order control on ice behavior, while seafloor geology played an important subsidiary role. Our analysis of retreat patterns further indicates that: (1) initial ice sheet retreat was initiated by a large grounding line embayment in the eastern Ross Sea; (2) retreat was highly variable and asynchronous between troughs; and (3) subglacial meltwater played a role in destabilizing grounding lines in parts of the western Ross Sea.

  20. Influence of hydrography on phytoplankton distribution in the Amundsen and Ross Seas, Antarctica

    NASA Astrophysics Data System (ADS)

    Fragoso, Glaucia M.; Smith, Walker O.

    2012-01-01

    The phytoplankton of the Ross Sea have been intensively studied, in contrast to that of the Amundsen Sea. This study focused on understanding the environmental variables that influence the spatial patterns of assemblages during late summer, 2007, and late spring-early summer, 2008 in the Amundsen and Ross Seas. Blooms of the prymnesiophyte Phaeocystis antarctica, and the silicoflagellate Dictyocha speculum occurred in the southwestern to eastern parts of the Ross Sea, respectively, whereas diatoms dominated in southeastern Ross and the Amundsen Sea. Shallow mixed layers supported the growth of diatoms, but were not the only factor required for diatom bloom development. Modified Circumpolar Deep Water intruded into the subsurface waters (< 200 m) in the southwestern Ross Sea during February 2007, and possibly favored the formation of P. antarctica blooms. Photosynthetic quantum yield data suggest that blooms from the southwestern Ross Sea were approaching stress during January 2008, likely due to iron limitation, in contrast to blooms close to the ice edge in the Amundsen Sea, where iron may be more available to the phytoplankton. A detailed comparison between the Amundsen and Ross Seas may allow a greater understanding of the environmental-induced impacts on phytoplankton distribution and regional biogeochemical cycles.

  1. Ross E. Baker, DC: A Canadian chiropractic survivor

    PubMed Central

    Brown, Douglas M.

    2014-01-01

    This paper is an historical biography of a fortunate man. It begins with a glimpse of Ross E. Baker’s origins in south-western Ontario, watches him going to school and working in Hamilton before joining the Canadian Army and shipping off to Europe to fight in the Second World War. At War’s end, the article picks up Dr. Baker as he comes home, starts a family, becomes a chiropractor and sustains a viable practice. Now in the twilight of life, the good doctor is last seen content with his retirement, spending days at his cottage property, reviewing his memoirs and reflecting on the tumult, terror and eventual triumph of the D-Day landing at Normandy. PMID:24587499

  2. Gaussian estimation for discretely observed Cox-Ingersoll-Ross model

    NASA Astrophysics Data System (ADS)

    Wei, Chao; Shu, Huisheng; Liu, Yurong

    2016-07-01

    This paper is concerned with the parameter estimation problem for Cox-Ingersoll-Ross model based on discrete observation. First, a new discretized process is built based on the Euler-Maruyama scheme. Then, the parameter estimators are obtained by employing the maximum likelihood method and the explicit expressions of the error of estimation are given. Subsequently, the consistency property of all parameter estimators are proved by applying the law of large numbers for martingales, Holder's inequality, B-D-G inequality and Cauchy-Schwarz inequality. Finally, a numerical simulation example for estimators and the absolute error between estimators and true values is presented to demonstrate the effectiveness of the estimation approach used in this paper.

  3. The Kubler-Ross model, physician distress, and performance reporting.

    PubMed

    Smaldone, Marc C; Uzzo, Robert G

    2013-07-01

    Physician performance reporting has been proposed as an essential component of health-care reform, with the aim of improving quality by providing transparency and accountability. Despite strong evidence demonstrating regional variation in practice patterns and lack of evidence-based care, public outcomes reporting has been met with resistance from medical professionals. Application of the Kubler-Ross 'five stages of grief' model--a conceptual framework consisting of a series of emotional stages (denial, anger, bargaining, depression, and acceptance) inspired by work with terminally ill patients--could provide some insight into why physicians are reluctant to accept emerging quality-reporting mechanisms. Physician-led quality-improvement initiatives are vital to contemporary health-care reform efforts and applications in urology, as well as other medical disciplines, are currently being explored.

  4. [A reappraisal of the works of Elisabeth Kubler-Ross].

    PubMed

    Afonso, Selene Beviláqua Chaves; Minayo, Maria Cecília de Souza

    2013-09-01

    This article presents a reappraisal of part of the works of Elizabeth Kubler-Ross, one of the most quoted authors addressing the end of life process, mourning and dying. Her work has contributed to a clearer understanding of these issues by health professionals, families, religious and lay people who handle and/or experience mourning. She has also been the subject of controversy related to ethical issues and the scientific rigor of her work. The books analyzed in this article are: On death and dying (1969); Questions and answers on death and dying (1971); Living with death and dying (1981); On children and death(1983); On life after death (1991) and Life lessons (2000).

  5. Albert Ross Tilley: The legacy of a Canadian plastic surgeon.

    PubMed

    Mowbrey, Kevin

    2013-01-01

    The present article chronicles the career of Dr Albert Ross Tilley, one of the most important Canadian plastic surgeons of the 20th century. Tilley is most well known for his innovations of burn management during World War II and his treatment of a group of burn patients known affectionately as the 'Guinea Pig Club'. In addition to the superb surgical skills he applied to the physical wounds of his patients, Tilley was also a pioneer of caring for the emotional and psychological afflictions suffered by many airmen of World War II. As one of the founding fathers of the Canadian Society of Plastic Surgeons, Tilley's work was instrumental in establishing the specialty and ensured its prosperity for years to come. Serving in the capacity of leader, educator and innovator, Tilley remains one of Canada's most decorated physicians, and his body of work encompasses contributions to the medical field that remain significant and beneficial to patient care to this day.

  6. Low-frequency microwave radiometer for N-ROSS

    NASA Technical Reports Server (NTRS)

    Hollinger, J. P.; Lo, R. C.

    1985-01-01

    The all weather, global determination of sea surface temperature (SST) has been identified as a requirement needed to support naval operations. The target SST accuracy is + or - 1.0 K with a surface resolution of 10 km. Investigations of the phenomenology and technology of remote passive microwave sensing of the ocean environment over the past decade have demonstrated that this objective is presently attainable. Preliminary specification and trade off studies were conducted to define the frequency, polarization, scan geometry, antenna size, and other esstential parameters of the low frequency microwave radiometer (LFMR). It will be a dual polarized, dual frequency system at 5.2 and 10.4 GHz using a 4.9 meter deployable mesh surface antenna. It is to be flown on the Navy-Remote Ocean Sensing System (N-ROSS) satellite scheduled to be launched in late 1988.

  7. The surface climatology of the Ross Ice Shelf Antarctica

    PubMed Central

    Lazzara, Matthew A.; Keller, Linda M.; Cassano, John J.

    2016-01-01

    ABSTRACT The University of Wisconsin‐Madison Antarctic Automatic Weather Station (AWS) project has been making meteorological surface observations on the Ross Ice Shelf (RIS) for approximately 30 years. This network offers the most continuous set of routine measurements of surface meteorological variables in this region. The Ross Island area is excluded from this study. The surface climate of the RIS is described using the AWS measurements. Temperature, pressure, and wind data are analysed on daily, monthly, seasonal, and annual time periods for 13 AWS across the RIS. The AWS are separated into three representative regions – central, coastal, and the area along the Transantarctic Mountains – in order to describe specific characteristics of sections of the RIS. The climatology describes general characteristics of the region and significant changes over time. The central AWS experiences the coldest mean temperature, and the lowest resultant wind speed. These AWSs also experience the coldest potential temperatures with a minimum of 209.3 K at Gill AWS. The AWS along the Transantarctic Mountains experiences the warmest mean temperature, the highest mean sea‐level pressure, and the highest mean resultant wind speed. Finally, the coastal AWS experiences the lowest mean pressure. Climate indices (MEI, SAM, and SAO) are compared to temperature and pressure data of four of the AWS with the longest observation periods, and significant correlation is found for most AWS in sea‐level pressure and temperature. This climatology study highlights characteristics that influence the climate of the RIS, and the challenges of maintaining a long‐term Antarctic AWS network. Results from this effort are essential for the broader Antarctic meteorology community for future research. PMID:28008213

  8. STS-110 Astronaut Jerry Ross Performs Extravehicular Activity (EVA)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Launched aboard the Space Shuttle Orbiter Atlantis on April 8, 2002, the STS-110 mission prepared the International Space Station (ISS) for future space walks by installing and outfitting the 43-foot-long Starboard side S0 (S-zero) truss and preparing the first railroad in space, the Mobile Transporter. The 27,000 pound S0 truss was the first of 9 segments that will make up the Station's external framework that will eventually stretch 356 feet (109 meters), or approximately the length of a football field. This central truss segment also includes a flatcar called the Mobile Transporter and rails that will become the first 'space railroad,' which will allow the Station's robotic arm to travel up and down the finished truss for future assembly and maintenance. The completed truss structure will hold solar arrays and radiators to provide power and cooling for additional international research laboratories from Japan and Europe that will be attached to the Station. STS-110 Extravehicular Activity (EVA) marked the first use of the Station's robotic arm to maneuver space walkers around the Station and was the first time all of a shuttle crew's space walks were based out of the Station's Quest Airlock. In this photograph, Astronaut Jerry L. Ross, mission specialist, anchored on the end of the Canadarm2, moves near the newly installed S0 truss. Astronaut Lee M. E. Morin, mission specialist, (out of frame), worked in tandem with Ross during this fourth and final scheduled session of EVA for the STS-110 mission. The final major task of the space walk was the installation of a beam, the Airlock Spur, between the Quest Airlock and the S0. The spur will be used by space walkers in the future as a path from the airlock to the truss.

  9. STS-110 Astronaut Jerry Ross Performs Extravehicular Activity (EVA)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Launched aboard the Space Shuttle Orbiter Atlantis on April 8, 2002, the STS-110 mission prepared the International Space Station (ISS) for future space walks by installing and outfitting the 43-foot-long Starboard side S0 (S-zero) truss and preparing the first railroad in space, the Mobile Transporter. The 27,000 pound S0 truss was the first of 9 segments that will make up the Station's external framework that will eventually stretch 356 feet (109 meters), or approximately the length of a football field. This central truss segment also includes a flatcar called the Mobile Transporter and rails that will become the first 'space railroad,' which will allow the Station's robotic arm to travel up and down the finished truss for future assembly and maintenance. The completed truss structure will hold solar arrays and radiators to provide power and cooling for additional international research laboratories from Japan and Europe that will be attached to the Station. STS-110 Extravehicular Activity (EVA) marked the first use of the Station's robotic arm to maneuver space walkers around the Station and was the first time all of a shuttle crew's space walks were based out of the Station's Quest Airlock. In this photograph, Astronaut Jerry L. Ross, mission specialist, anchored on the end of the Canadarm2, moves near the newly installed S0 truss. Astronaut Lee M. E. Morin, mission specialist, (out of frame), worked in tandem with Ross during this fourth and final scheduled session of EVA for the STS-110 mission. The final major task of the space walk was the installation of a beam, the Airlock Spur, between the Quest Airlock and the S0. The spur will be used by space walkers in the future as a path from the airlock to the truss.

  10. Mesoscale cyclogenesis dynamics over the southwestern Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Carrasco, Jorge F.; Bromwich, David H.

    1993-07-01

    Previous work has shown that frequent mesoscale cyclogenesis adjacent to Franklin Island is linked to the strong and persistent katabatic winds from East Antarctica which funnel into Terra Nova Bay and then blow out over the southwestern Ross Sea. Four mesoscale cyclones that formed near Terra Nova Bay between February 16 and 20, 1988 are examined to more clearly define the governing mechanisms. These events are investigated using all available observations, including automatic weather station data, high-resolution satellite images, satellite soundings, and hemispheric synoptic analyses. The first two cyclones formed on low-level baroclinic zones established by the synoptic scale advection of warm moist air toward the cold continental air blowing gently from East Antarctica. In the second case, baroclinic instability of this small-scale cold front was apparently triggered by the enhanced upward vertical motion associated with the approach of a midtropospheric trough. The third mesocyclone formed shortly after on a baroclinic zone over the polar plateau; the second vortex completely disrupted the usual katabatic drainage over the plateau and forced warm moist air over the coastal slopes. All three cyclones moved to the north in the prevailing cyclonic flow, but the plateau vortex lasted for only 6 hours. The fourth mesoscale low formed in conjunction with an abrupt and intense surge of katabatic air from Terra Nova Bay which resharpened the coastal baroclinic zone. At the same time a transiting midtropospheric trough probably associated with lower tropospheric upward vertical motion apparently accelerated the katabatic winds and triggered the vortex formation. A similar katabatic wind-forced mesocyclone formed near Byrd Glacier. The two vortices moved to the east-southeast and northeast, respectively, apparently being steered by the generating katabatic airstreams, and merged just to the north of the Ross Ice Shelf. The combined vortex reintensified as another

  11. The surface climatology of the Ross Ice Shelf Antarctica.

    PubMed

    Costanza, Carol A; Lazzara, Matthew A; Keller, Linda M; Cassano, John J

    2016-12-01

    The University of Wisconsin-Madison Antarctic Automatic Weather Station (AWS) project has been making meteorological surface observations on the Ross Ice Shelf (RIS) for approximately 30 years. This network offers the most continuous set of routine measurements of surface meteorological variables in this region. The Ross Island area is excluded from this study. The surface climate of the RIS is described using the AWS measurements. Temperature, pressure, and wind data are analysed on daily, monthly, seasonal, and annual time periods for 13 AWS across the RIS. The AWS are separated into three representative regions - central, coastal, and the area along the Transantarctic Mountains - in order to describe specific characteristics of sections of the RIS. The climatology describes general characteristics of the region and significant changes over time. The central AWS experiences the coldest mean temperature, and the lowest resultant wind speed. These AWSs also experience the coldest potential temperatures with a minimum of 209.3 K at Gill AWS. The AWS along the Transantarctic Mountains experiences the warmest mean temperature, the highest mean sea-level pressure, and the highest mean resultant wind speed. Finally, the coastal AWS experiences the lowest mean pressure. Climate indices (MEI, SAM, and SAO) are compared to temperature and pressure data of four of the AWS with the longest observation periods, and significant correlation is found for most AWS in sea-level pressure and temperature. This climatology study highlights characteristics that influence the climate of the RIS, and the challenges of maintaining a long-term Antarctic AWS network. Results from this effort are essential for the broader Antarctic meteorology community for future research.

  12. Two-dimensional Tomographic Inversion Model of Ross Island, Antarctica

    NASA Astrophysics Data System (ADS)

    Maraj, S.; Aster, R. C.; Knox, H. A.; Zandomeneghi, D.; Snelson, C. M.; Kyle, P. R.

    2010-12-01

    A controlled-source seismic refraction experiment (Tomo-Erebus; TE) was undertaken during the 2008-09 Austral summer field season to examine the magmatic system beneath the active Erebus volcano (TE-3D) and the crustal structure beneath Ross Island, including details of the Terror Rift (TE-2D). Previous geophysical studies north of Ross Island have determined the north-south trending Terror Rift within the broader Victoria Land Basin, which are part of the intraplate West Antarctic Rift System. For TE-2D, 21 seismic recorders (Ref Tek 130) with three-component 4.5 Hz geophones (Sercel L-28-3D) were deployed along a 77-km east-west line between Capes Royds and Crozier. For TE-3D, 79 similar instruments were deployed in a 3 x 3 km grid around the crater of Erebus, an array of 8 permanent short period and broadband sensors and 23 three-component sensors (Guralp CMG-40T, 30s-100 Hz) were positioned around the flanks and summit of Erebus. Fifteen chemical sources ranging from 75 to 600 kg of ANFO were used. An additional shot was detonated in the sea (McMurdo Sound) using 200 kg of dynamite. Although the station spacing is ~5 km, the data have a high signal to noise ratio with clear first arrivals and wide-angle reflections across the array. Forward modelling ray tracing was used to develop 1-D P-wave velocity models by matching layers of known velocities with the P-wave first arrival times. 1-D velocity models developed for 3 sources and show ~3 layers with a velocity of ~7 km/s below 6-8 km depth. The 1-D models were used as the starting model for a the P-wave tomographic velocity model.

  13. Freshening of the Ross Sea during the late 20th century.

    PubMed

    Jacobs, S S; Giulivi, C F; Mele, P A

    2002-07-19

    Ocean measurements in the Ross Sea over the past four decades, one of the longest records near Antarctica, reveal marked decreases in shelf water salinity and the surface salinity within the Ross Gyre. These changes have been accompanied by atmospheric warming on Ross Island, ocean warming at depths of approximately 300 meters north of the continental shelf, a more negative Southern Oscillation Index, and thinning of southeast Pacific ice shelves. The freshening appears to have resulted from a combination of factors, including increased precipitation, reduced sea ice production, and increased melting of the West Antarctic Ice Sheet.

  14. Elisabeth Kubler-Ross and the Tradition of the Private Sphere: An Analysis of Symbols.

    ERIC Educational Resources Information Center

    Klass, Dennis

    1981-01-01

    Shows how Kubler-Ross' schema functions as a symbol system. Analyzes the symbol "acceptance." Shows how that symbol is part of a strong American tradition of symbols of the private sphere. (Author/JAC)

  15. Quadruple valve replacement and bypass surgery 23 years after the Ross operation†.

    PubMed

    Oeser, Claudia; Andreas, Martin; Habertheuer, Andreas; Kocher, Alfred

    2015-07-01

    This report describes a case of simultaneous quadruple valve replacement, coronary artery bypass surgery and reconstruction of one aortic sinus performed in a patient who had undergone the Ross operation 23 years previously.

  16. Elisabeth Kubler-Ross and the Tradition of the Private Sphere: An Analysis of Symbols.

    ERIC Educational Resources Information Center

    Klass, Dennis

    1981-01-01

    Shows how Kubler-Ross' schema functions as a symbol system. Analyzes the symbol "acceptance." Shows how that symbol is part of a strong American tradition of symbols of the private sphere. (Author/JAC)

  17. STS-37 Mission Specialist (MS) Ross during EVA in OV-104's payload bay

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-37 Mission Specialist (MS) Jerry L. Ross drifts outside Atlantis', Orbiter Vehicle (OV) 104's, payload bay (PLB) as he attaches a tether to a port side guidewire during extravehicular activity (EVA). OV-104's wing tip is visible below Ross. The Crew and Equipment Translation Aid (CETA) deployable track appears mounted inside the PLB. Only the shoulder and upper arm of the deployed remote manipulator system (RMS) are visible at the right.

  18. STS-37 MS Godwin balances MS Ross using her index finger on OV-104's middeck

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-37 Mission Specialist (MS) Linda M. Godwin holds MS Jerry L. Ross over her head using only her index finger. The two crewmembers are participating in a microgravity balancing act on the middeck of Atlantis, Orbiter Vehicle (OV) 104. The Bioserve Instrumentation Technology Associates Materials Dispersion Apparatus (BIMDA) bioprocessing test bed mixing and sampling configuration is attached to the forward middeck lockers at Ross' right. The sleep restraints are attached on the starboard wall behind the astronauts.

  19. STS-37 Mission Specialist (MS) Ross during EVA in OV-104's payload bay

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-37 Mission Specialist (MS) Jerry L. Ross drifts outside Atlantis', Orbiter Vehicle (OV) 104's, payload bay (PLB) as he attaches a tether to a port side guidewire during extravehicular activity (EVA). OV-104's wing tip is visible below Ross. The Crew and Equipment Translation Aid (CETA) deployable track appears mounted inside the PLB. Only the shoulder and upper arm of the deployed remote manipulator system (RMS) are visible at the right.

  20. Frank Ross's Early Direct Photographs of Venus and His Interpretation of Them

    NASA Astrophysics Data System (ADS)

    Osterbrock, Donald E.

    2006-09-01

    Frank Ross was an outstandingly creative astronomical "jack of many trades" (Monet) or "cat with nine astronomical lives". After joining the Yerkes Observatory faculty in 1924, at age 50, he took a long series of almost nightly direct photographs of Venus in 1927 with the Mount Wilson 60-inch and 100-inch reflectors as a guest observer. He published many of these images in the ApJ in 1928, with his conclusions on the nature of Venus. Ross discovered markings, seen only in the ultraviolet images, parallel "belts" indicating rotation. They changed rapidly. From these photographs he developed a tentative picture of a deep opaque atmosphere, with high pressure at the surface of the planet. The changes were due to "violent events" (winds or storms) in its atmosphere. From spectroscopic results of Slipher, Adams, StJohn, and Nicholson he took the rotation period to be long. But bolometric observations of Pettit, Nicholson, Coblentz, and Lampland, indicated little temperature change between the illuminated and dark parts of the disk, so it could not be too slow. Ross settled on a "compromise" rotation period of about 30 days based on the data he had. The spectroscopic measurements showed there was very little, if any, H2O or O2 in the atmosphere. Ross is best known today for his Ross wide-angle camera design, his Ross high-proper-motion stars, his Ross photometer, and his Ross correctors for large reflecting telescopes, but his foray into planetary astronomy, long before the era of radar or close-up imaging and spectroscopy from space vehicles, was an important first step toward understanding Venus. His years of experience in laboratory studies of the properties of photographic plates, developers, and mensuration were highly important for this work. Equally so were his cheerful, peppery personality and his close relations with many Mount Wilson and Lowell Observatory staff members.

  1. Comparison of Cobb and Ross strains in embryo physiology and chick juvenile growth.

    PubMed

    Tona, K; Onagbesan, O M; Kamers, B; Everaert, N; Bruggeman, V; Decuypere, E

    2010-08-01

    Broiler performance is known to be related to embryonic developmental parameters. However, strain or genotype differences with regard to embryo physiological parameters and juvenile growth have received little attention. A total of 1,200 hatching eggs produced by Cobb and Ross broiler breeders of the same age were studied. At setting for incubation and between 66 and 130 h of incubation, egg resonant frequency (RF) was measured as an indicator of embryonic development. Also, eggs were weighed before setting and at d 18. From d 10 to 18 of incubation, remaining albumen was weighed. During the last days of incubation, hatching events such as internal pipping (IP), external pipping, and hatch were monitored every 2 h. Hatched chicks were recorded and weighed. At IP stage, gas partial pressures in the egg air chamber were measured. Hatched chicks were reared for 7 d and weighed. Results indicate that RF of Ross eggs were lower than those of Cobb eggs (P < 0.01) and starting time point of RF decrease occurred earlier in Cobb eggs than in Ross eggs. Relative egg weight loss up to 18 d of incubation was lower in Cobb than in Ross (P < 0.05). At IP, partial pressure of CO(2) was higher in Cobb than in Ross (P < 0.05) with shorter incubation duration in Cobb. Between 6 and 60 h posthatch, heat production was higher in Cobb than in Ross (P < 0.05). At 7 d posthatch, Cobb chicks were heavier than Ross chicks (P < 0.05). It is concluded that Cobb and Ross embryos-chicks have different growth trajectories leading in different patterns of growth resulting from differences in physiological parameters.

  2. Fish, crustaceans, and the sea floor under the ross ice shelf.

    PubMed

    Bruchhausen, P M; Raymond, J A; Jacobs, S S; Devries, A L; Thorndike, E M; Dewitt, H H

    1979-02-02

    Baited traps and a camera lowered through the Ross Ice Shelf, Antarctica, at a point 475 kilometers from the open Ross Sea and to 597 meters below sea level revealed the presence of fish, many amphipods, and one isopod. Biological or current markings were not evident on a soft bottom littered with subangular lumps. A fish was caught through a crevasse 80 kilometers from the shelf edge.

  3. Ross Sea Till Properties: Implications for Ice Sheet Bed Interaction

    NASA Astrophysics Data System (ADS)

    Halberstadt, A. R.; Anderson, J. B.; Simkins, L.; Prothro, L. O.; Bart, P. J.

    2015-12-01

    Since the discovery of a pervasive shearing till layer underlying Ice Stream B, the scientific community has categorized subglacial diamictons as either deformation till or lodgement till primarily based on shear strength. Deformation till is associated with streaming ice, formed through subglacial deformation of unconsolidated sediments. Lodgement till is believed to be deposited by the plastering of sediment entrained at the base of slow-flowing ice onto a rigid bed. Unfortunately, there has been a paucity of quantitative data on the spatial distribution of shear strength across the continental shelf. Cores collected from the Ross Sea on cruises NBP1502 and NBP9902 provide a rich dataset that can be used to interpret till shear strength variability. Till strengths are analyzed within the context of: (1) geologic substrate; (2) water content and other geotechnical properties; (3) ice sheet retreat history; and (4) geomorphic framework. Tills display a continuum of shear strengths rather than a bimodal distribution, suggesting that shear strength cannot be used to distinguish between lodgement and deformation till. Where the substrate below the LGM unconformity is comprised of older lithified deposits, till shear strengths are both highly variable within the till unit, as well as highly variable between cores. Conversely, where ice streams flowed across unconsolidated Plio-Pleistocene deposits, shear strengths are low and less variable within the unit and between cores. This suggests greater homogenization of cannibalized tills, and possibly a deeper pervasive shear layer. Coarser-grained tills are observed on banks and bank slopes, with finer tills in troughs. Highly variable and more poorly sorted tills are found in close proximity to sediment-based subglacial meltwater channels, attesting to a change in ice-bed interaction as subglacial water increases. Pellets (rounded sedimentary clasts of till matrix) are observed in Ross Sea cores, suggesting a history of

  4. Mass Balance and Structure of the Ross Ice Shelf

    NASA Astrophysics Data System (ADS)

    Das, I.; Padman, L.; Chu, W.; Fricker, H. A.; Becker, M. K.; Bell, R. E.; Tinto, K. J.; Millstein, J. D.

    2016-12-01

    Changes in ice shelf mass balance is key to the long term stability of the Antarctic ice sheet. Although the most extensive thinning occurs on the Amundsen Sea sector of West Antarctica, recent studies indicate that many other ice shelves are also experiencing widespread thinning. Here, we focus on the Ross Ice Self. An 18-year record (1994-2012) of satellite radar altimetry shows elevation change 1 m/yr across the shelf. Significant variability in ice shelf height on interannual time scales makes it difficult to detect a long-term mass budget trend of this ice shelf. Variability of radar signal penetration into the ice-shelf snow and firn layers further complicates assessment of mass changes. In this work, we investigate the Ross Ice Shelf mass balance using aerogeophyical data from the ROSETTA-ICE IcePod and NASA's Operation IceBridge. ROSSETTA-ICE is an aerogeophysical program planned to survey the ice shelf at a 10 km spacing over the course of two field seasons-2015 and 2016. This NSF/Moore Foundation supported multi-University collaborative project is designed to provide an integrated view of the ice shelf and the underlying bathymetry using the IcePod system including its ice-penetrating radars, laser altimetry, gravity meters and magnetometers. We present preliminary results from our ongoing efforts of quantifying the mass balance of the ice shelf using IcePod ice penetrating radars and laser altimetry along with satellite data. We will use internal layers traced from ice penetrating radars to outline the structure of the ice shelf. Airborne laser altimetry measurements from this IcePod survey and IceBridge will be used to study the elevation change of the ice shelf. Spatial variations of thickness of the internal layers in the first few meters of the ice shelf, particularly near the grounding line, will indicate the impact of wind-blown snow coming from the continent onto the ice shelf. In order to infer conditions of melt and freeze-on at the ice

  5. Neogene Development of the Terror Rift, western Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Sauli, C.; Sorlien, C. C.; Busetti, M.; De Santis, L.; Wardell, N.; Henrys, S. A.; Geletti, R.; Wilson, T. J.; Luyendyk, B. P.

    2015-12-01

    Terror Rift is a >300 km-long, 50-70 km-wide, 14 km-deep sedimentary basin at the edge of the West Antarctic Rift System, adjacent to the Transantarctic Mountains. It is cut into the broader Victoria Land Basin (VLB). The VLB experienced 100 km of mid-Cenozoic extension associated with larger sea floor spreading farther north. The post-spreading (Neogene) development of Terror Rift is not well understood, in part because of past use of different stratigraphic age models. We use the new Rossmap seismic stratigraphy correlated to Cape Roberts and Andrill cores in the west and to DSDP cores in the distant East. This stratigraphy, and new fault interpretations, was developed using different resolutions of seismic reflection data included those available from the Seismic Data Library System. Depth conversion used a new 3D velocity model. A 29 Ma horizon is as deep as 8 km in the south, and a 19 Ma horizon is >5 km deep there and 4 km-deep 100 km farther north. There is a shallower northern part of Terror Rift misaligned with the southern basin across a 50 km right double bend. It is bounded by steep N-S faults down-dropping towards the basin axis. Between Cape Roberts and Ross Island, the Oligocene section is also progressively-tilted. This Oligocene section is not imaged within northern Terror Rift, but the simplest hypothesis is that some of the Terror Rift-bounding faults were active at least during Oligocene through Quaternary time. Many faults are normal separation, but some are locally vertical or even reverse-separation in the upper couple of km. However, much of the vertical relief of the strata is due to progressive tilting (horizontal axis rotation) and not by shallow faulting. Along the trend of the basin, the relief alternates between tilting and faulting, with a tilting margin facing a faulted margin across the Rift, forming asymmetric basins. Connecting faults across the basin form an accommodation zone similar to other oblique rifts. The Neogene basin is

  6. Long-term productivity in the cryptoendolithic microbial community of the Ross Desert, Antarctica.

    PubMed

    Friedmann, E I; Kappen, L; Meyer, M A; Nienow, J A

    1993-01-01

    Annual gross productivity of the lichen-dominated cryptoendolithic community was calculated from a computer analysis of photosynthetic response based on laboratory measurements of CO2 exchange and three years (1985-1988) of field nanoclimate data. Photosynthetic optimum increased from -3 to 2 degrees C between irradiance levels of 100 and 1500 micromoles photons m-2 s-1, while the upper compensation point rose from 1 to 17 degrees C. The mean yearly total time available for metabolic activity (temperature above -10 degrees C and moisture present) was 771.3 h for horizontal rock, 421.5 h for northeast-oriented sloped rock, and 1042.2 h for a small depression in horizontal rock (the characteristic site of occasional lichen apothecia). The calculated mean gross productivity value for a horizontal rock was 1215 mg C m-2 y-1, and net photosynthetic gain was 606 mg C m-2 y-1. Net ecosystem productivity (annual accretion of cellular biomass) estimated from long-term events amounted to only about 3 mg C m-2 y-1. The difference between these two values may represent the long-term metabolic costs of the frequent dehydration-rehydration and freezing-thawing cycles or of overwintering, and may account for the leaching of organic substances to the rock. The yearly gross productivity of the cryptoendolithic microbial community of the entire Ross Desert area was estimated at approximately 120,000-180,000 kg C. Of this, 600-900 kg C is in microbial biomass, and much of the rest is soluble compounds that leach into the rocks and possibly percolate to the valleys, providing a source of organic matter for lakes, rivers, and soils.

  7. Long-term productivity in the cryptoendolithic microbial community of the Ross Desert, Antarctica

    NASA Technical Reports Server (NTRS)

    Friedmann, E. I.; Kappen, L.; Meyer, M. A.; Nienow, J. A.

    1993-01-01

    Annual gross productivity of the lichen-dominated cryptoendolithic community was calculated from a computer analysis of photosynthetic response based on laboratory measurements of CO2 exchange and three years (1985-1988) of field nanoclimate data. Photosynthetic optimum increased from -3 to 2 degrees C between irradiance levels of 100 and 1500 micromoles photons m-2 s-1, while the upper compensation point rose from 1 to 17 degrees C. The mean yearly total time available for metabolic activity (temperature above -10 degrees C and moisture present) was 771.3 h for horizontal rock, 421.5 h for northeast-oriented sloped rock, and 1042.2 h for a small depression in horizontal rock (the characteristic site of occasional lichen apothecia). The calculated mean gross productivity value for a horizontal rock was 1215 mg C m-2 y-1, and net photosynthetic gain was 606 mg C m-2 y-1. Net ecosystem productivity (annual accretion of cellular biomass) estimated from long-term events amounted to only about 3 mg C m-2 y-1. The difference between these two values may represent the long-term metabolic costs of the frequent dehydration-rehydration and freezing-thawing cycles or of overwintering, and may account for the leaching of organic substances to the rock. The yearly gross productivity of the cryptoendolithic microbial community of the entire Ross Desert area was estimated at approximately 120,000-180,000 kg C. Of this, 600-900 kg C is in microbial biomass, and much of the rest is soluble compounds that leach into the rocks and possibly percolate to the valleys, providing a source of organic matter for lakes, rivers, and soils.

  8. Long-term productivity in the cryptoendolithic microbial community of the Ross Desert, Antarctica

    NASA Technical Reports Server (NTRS)

    Friedmann, E. I.; Kappen, L.; Meyer, M. A.; Nienow, J. A.

    1993-01-01

    Annual gross productivity of the lichen-dominated cryptoendolithic community was calculated from a computer analysis of photosynthetic response based on laboratory measurements of CO2 exchange and three years (1985-1988) of field nanoclimate data. Photosynthetic optimum increased from -3 to 2 degrees C between irradiance levels of 100 and 1500 micromoles photons m-2 s-1, while the upper compensation point rose from 1 to 17 degrees C. The mean yearly total time available for metabolic activity (temperature above -10 degrees C and moisture present) was 771.3 h for horizontal rock, 421.5 h for northeast-oriented sloped rock, and 1042.2 h for a small depression in horizontal rock (the characteristic site of occasional lichen apothecia). The calculated mean gross productivity value for a horizontal rock was 1215 mg C m-2 y-1, and net photosynthetic gain was 606 mg C m-2 y-1. Net ecosystem productivity (annual accretion of cellular biomass) estimated from long-term events amounted to only about 3 mg C m-2 y-1. The difference between these two values may represent the long-term metabolic costs of the frequent dehydration-rehydration and freezing-thawing cycles or of overwintering, and may account for the leaching of organic substances to the rock. The yearly gross productivity of the cryptoendolithic microbial community of the entire Ross Desert area was estimated at approximately 120,000-180,000 kg C. Of this, 600-900 kg C is in microbial biomass, and much of the rest is soluble compounds that leach into the rocks and possibly percolate to the valleys, providing a source of organic matter for lakes, rivers, and soils.

  9. Quantifying fall migration of Ross's gulls (Rhodostethia rosea) past Point Barrow, Alaska

    USGS Publications Warehouse

    Uher-Koch, Brian D.; Davis, Shanti E.; Maftei, Mark; Gesmundo, Callie; Suydam, R.S.; Mallory, Mark L.

    2014-01-01

    The Ross's gull (Rhodostethia rosea) is a poorly known seabird of the circumpolar Arctic. The only place in the world where Ross's gulls are known to congregate is in the near-shore waters around Point Barrow, Alaska where they undertake an annual passage in late fall. Ross's gulls seen at Point Barrow are presumed to originate from nesting colonies in Siberia, but neither their origin nor their destination has been confirmed. Current estimates of the global population of Ross's gulls are based largely on expert opinion, and the only reliable population estimate is derived from extrapolations from previous counts conducted at Point Barrow, but these data are now over 25 years old. In order to update and clarify the status of this species in Alaska, our study quantified the timing, number, and flight direction of Ross's gulls passing Point Barrow in 2011. We recorded up to two-thirds of the estimated global population of Ross's gulls (≥ 27,000 individuals) over 39 days with numbers peaking on 16 October when we observed over 7,000 birds during a three-hour period.

  10. Ross, macdonald, and a theory for the dynamics and control of mosquito-transmitted pathogens.

    PubMed

    Smith, David L; Battle, Katherine E; Hay, Simon I; Barker, Christopher M; Scott, Thomas W; McKenzie, F Ellis

    2012-01-01

    Ronald Ross and George Macdonald are credited with developing a mathematical model of mosquito-borne pathogen transmission. A systematic historical review suggests that several mathematicians and scientists contributed to development of the Ross-Macdonald model over a period of 70 years. Ross developed two different mathematical models, Macdonald a third, and various "Ross-Macdonald" mathematical models exist. Ross-Macdonald models are best defined by a consensus set of assumptions. The mathematical model is just one part of a theory for the dynamics and control of mosquito-transmitted pathogens that also includes epidemiological and entomological concepts and metrics for measuring transmission. All the basic elements of the theory had fallen into place by the end of the Global Malaria Eradication Programme (GMEP, 1955-1969) with the concept of vectorial capacity, methods for measuring key components of transmission by mosquitoes, and a quantitative theory of vector control. The Ross-Macdonald theory has since played a central role in development of research on mosquito-borne pathogen transmission and the development of strategies for mosquito-borne disease prevention.

  11. Ross, Macdonald, and a Theory for the Dynamics and Control of Mosquito-Transmitted Pathogens

    PubMed Central

    Smith, David L.; Battle, Katherine E.; Hay, Simon I.; Barker, Christopher M.; Scott, Thomas W.; McKenzie, F. Ellis

    2012-01-01

    Ronald Ross and George Macdonald are credited with developing a mathematical model of mosquito-borne pathogen transmission. A systematic historical review suggests that several mathematicians and scientists contributed to development of the Ross-Macdonald model over a period of 70 years. Ross developed two different mathematical models, Macdonald a third, and various “Ross-Macdonald” mathematical models exist. Ross-Macdonald models are best defined by a consensus set of assumptions. The mathematical model is just one part of a theory for the dynamics and control of mosquito-transmitted pathogens that also includes epidemiological and entomological concepts and metrics for measuring transmission. All the basic elements of the theory had fallen into place by the end of the Global Malaria Eradication Programme (GMEP, 1955–1969) with the concept of vectorial capacity, methods for measuring key components of transmission by mosquitoes, and a quantitative theory of vector control. The Ross-Macdonald theory has since played a central role in development of research on mosquito-borne pathogen transmission and the development of strategies for mosquito-borne disease prevention. PMID:22496640

  12. Confirming and Improving Ross Variable Star RV Del

    NASA Astrophysics Data System (ADS)

    Linder, Tyler R.; Sanchez, Rick; Palser, Sage; Schultze, Kendra; Kenney, Jessica; Thompson, Briana; DeCoster, Richard; Mills, Frank; Osborn, Wayne; Hoette, Vivian L.; Skynet Junior Scholars; Stone Edge Observatory

    2017-01-01

    RV Del is an intrinsic pulsating variable star in the constellation Delphinus, discovered by Ross (1926). The AAVSO list RV Del as a RRAB type of variable star. RV Del has been found to have a magnitude that varies from 12.9 - 14.2 and a period of 11.9553 hours.The purpose of our research of RV Del is to confirm and improve previous results as well as explore different methods to engage middle school students in the scientific method and astronomy. The SKYNET network of telescopes allows students to request images from a group of international research class telescopes. The telescope request process allows students first-hand experience in astronomy while the data analysis allows students to understand advance software systems to produce publishable results. Data is being gathered using the SKYNET network and Stone Edge Observatory to gather photometry of RV Del and create a new light curve. Findings will be presented the January 2017 AAS.

  13. STS-88 Mission Specialist Ross arrives for launch

    NASA Technical Reports Server (NTRS)

    1998-01-01

    A smiling Mission Specialist Jerry L. Ross prepares to exit the T-38 jet aircraft that brought him to the Shuttle Landing Facility. He joins other crew members Mission Commander Robert D. Cabana, Pilot Frederick W. 'Rick' Sturckow, Mission Specialist Nancy J. Currie, Mission Specialist James H. Newman and Mission Specialist Sergei Konstantinovich Krikalev, a Russian cosmonaut, for pre-launch preparations for mission STS-88 aboard Space Shuttle Endeavour. The scheduled time of launch is 3:56 a.m. EST on Dec. 3 from Launch Pad 39A. The mission is the first U.S. launch for the International Space Station. Endeavour carries the Unity connecting module which the crew will be mating with the Russian-built Zarya control module already in orbit. In addition to Unity, two small replacement electronics boxes are on board for possible repairs to Zarya batteries. Endeavour is expected to land at KSC at 10:17 p.m. on Monday, Dec. 14.

  14. Movement of fuel spills in the Ross Ice Shelf

    SciTech Connect

    Tumeo, M.A.; Larson, M.K.

    1994-12-31

    Williams Field provides logistical support to McMurdo Station in Antarctica and managers large amounts of fuel for their cargo planes. Numerous spills have occurred at this site with little recovery or remediation of the spilled fuel. From 1980 to 1989, approximately 380,000 liters (L) leaked during documented fuel spills-197,600 L of that total came from one spill alone, in October of 1989, when fuel leaked onto the ice at Williams Field. An additional 20 spills of unknown quantities have also occurred at McMurdo Station and Williams Field. Although recent improvements in equipment and procedures in Antarctica have significantly reduced the accidental release of fuel and all but eliminated the risk of a large fuel spill, the potential for small releases still exists. To track the movement of fuel spills on the ice shelf more accurately and to established the basis for remediation methods NSF funded a 3-year study. This article discusses information obtained about the movement of fuel from a small oil spill from a flexible pipeline between McMurdo Station and Williams Field on the Ross Ice Shelf. 1 fig., 1 tab.

  15. STS-88 Mission Specialist Ross arrives for launch

    NASA Technical Reports Server (NTRS)

    1998-01-01

    A smiling Mission Specialist Jerry L. Ross prepares to exit the T-38 jet aircraft that brought him to the Shuttle Landing Facility. He joins other crew members Mission Commander Robert D. Cabana, Pilot Frederick W. 'Rick' Sturckow, Mission Specialist Nancy J. Currie, Mission Specialist James H. Newman and Mission Specialist Sergei Konstantinovich Krikalev, a Russian cosmonaut, for pre-launch preparations for mission STS-88 aboard Space Shuttle Endeavour. The scheduled time of launch is 3:56 a.m. EST on Dec. 3 from Launch Pad 39A. The mission is the first U.S. launch for the International Space Station. Endeavour carries the Unity connecting module which the crew will be mating with the Russian-built Zarya control module already in orbit. In addition to Unity, two small replacement electronics boxes are on board for possible repairs to Zarya batteries. Endeavour is expected to land at KSC at 10:17 p.m. on Monday, Dec. 14.

  16. Albert Ross Tilley: The legacy of a Canadian plastic surgeon

    PubMed Central

    Mowbrey, Kevin

    2013-01-01

    The present article chronicles the career of Dr Albert Ross Tilley, one of the most important Canadian plastic surgeons of the 20th century. Tilley is most well known for his innovations of burn management during World War II and his treatment of a group of burn patients known affectionately as the ‘Guinea Pig Club’. In addition to the superb surgical skills he applied to the physical wounds of his patients, Tilley was also a pioneer of caring for the emotional and psychological afflictions suffered by many airmen of World War II. As one of the founding fathers of the Canadian Society of Plastic Surgeons, Tilley’s work was instrumental in establishing the specialty and ensured its prosperity for years to come. Serving in the capacity of leader, educator and innovator, Tilley remains one of Canada’s most decorated physicians, and his body of work encompasses contributions to the medical field that remain significant and beneficial to patient care to this day. PMID:24431953

  17. Seasonal circulation under the eastern Ross Ice Shelf, Antarctia

    SciTech Connect

    Hellmer, H.H.; Jacobs, S.S.

    1995-06-15

    An annual cycle of shelf water temperatures and salinities measured at depth near the eastern Ross Ice Shelf front is used to force a two-dimensional thermohaline circulation model adapted to different subice paths in the vicinity of Roosevelt Island. These paths were assumed to have constant water column thicknesses of 160, 200, and 240 m and lengths of 460-800 km. Additional simulations with the longer cavity included a 80-m thick interior water column in order to approximate conditions closer to the grounding line. Model results were compared with other long-term measurements that showed outflow from beneath the ice shelf. Shelf water flowing into the cavity west of Roosevelt Island appears to follow a cyclonic route around the island. The ice shelf base loses mass at a rate of 18-27 cm yr{sup {minus}1}, with seasonal forcing increasing the spatial and temporal variability of circulation and property distributions in the larger cavities. Shallow cavities reduce the influence of shelf water variability with increasing length. Introducing a transient shelf water temperature rise of 0.01{degrees}C yr {sup {minus}1} for 100 years increases the melt rate by 4-5 times. However, this increase is smaller if salinity also decreases over the same period of time, as might be expected from the added meltwater component. 42 refs., 9 figs.

  18. Antarctic marine ice sheet retreat in the Ross Sea during the early Holocene

    NASA Astrophysics Data System (ADS)

    Mckay, R. M.; Golledge, N.; Naish, T.; Maas, S.; Levy, R. H.; Kuhn, G.; Lee, J. I.; Dunbar, G. B.

    2015-12-01

    Geological constraints on the timing of the retreat of the Last Glacial Maximum (LGM) Antarctic Ice Sheets provide critical insights into the processes controlling marine-based ice sheet stability. The over-deepened, seaward shallowing bathymetry of Antarctica's continental shelves is ideally configured to promote past, and potentially future, marine ice-sheet instability. The retreat history of the LGM ice sheet in the Ross Sea region is primarily constrained by C-14 ages on coastal beach ridges and relict penguin colonies along the Transantarctic Mountain front in the Western Ross Sea. Although these terrestrial sites offer more reliable dates than imprecise C-14 chronologies derived from bulk marine sediments, they may reflect retreat of local piedmont glaciers derived from East Antarctic outlet glaciers rather than representing the timing of retreat of the ice sheet in the central Ross Embayment. We present a sedimentary facies succession and foraminifera-based C-14 chronology from a core collected beneath the Ross Ice Shelf via a hot water drill access hole used for the ANDRILL Coulman High site survey. The site is to the east of Ross Island and distal from the coast, and yields a minimum age for glacial retreat that is approximately 1000 yrs earlier than suggested by coastal records along the nearby Victoria Land coast. We examine the implications of this constraint on the timing of ice sheet retreat in the context of model simulations and new multi-beam bathymetry data acquired in the Western Ross Sea. On the basis of these data we hypothesize that marine-based ice sheet retreat was triggered by oceanic forcings along most of the Pacific Ocean coastline of Antarctica simultaneously, but continued retreat in the Ross Sea occurred primarily as a consequence of marine ice sheet instability.

  19. Grounding zone heterogeneity around the Ross Ice Shelf

    NASA Astrophysics Data System (ADS)

    Marsh, Oliver; Floricioiu, Dana; Rack, Wolfgang

    2017-04-01

    Grounding lines are most accurately mapped by identifying patterns of differential vertical movement from SAR interferometry. The apparent grounding line position at the upstream limit of flexure and the width of the flexure zone are influenced by satellite acquisition time relative to the tides, even for steep bedrock slopes. Here we identify and interpret spatial variations in flexure around the Ross Ice Shelf using a suite of TerraSAR-X interferograms. A small change in grounding line position can indicate short-term dynamic variability in ice thickness or the onset of ocean-induced instability, though neither are observed here. Nevertheless, interferograms also contain information about the stiffness of ice, its time-dependent response to tides and basal characteristics at the ice shelf boundary. Using flexure zone width, we estimate ice stiffness and link it to variations in thickness and rheology. Surface profiles across the grounding line from ICESat laser altimetry are re-interpreted and used to clarify the process of buoyancy-induced bending. Observations match well to theoretical models predicting an ice-shelf bump of variable amplitude and wavelength downstream of the transition. A deviation from hydrostatic balance is particularly clear at the steep, fast-flowing outlet glaciers of the Transantarctic Mountains (Mulock / Beardmore) but is also found in non-moving areas such as the Kamb Ice Stream. This deviation can lead to a positive bias of up to 15% of ice thickness and may cause significant miscalculation of ice shelf basal melt rates and errors in 'flux gate' type mass balance calculations. Here, cross-sections through the grounding line are modelled analytically in 1D from fundamental glaciological parameters using the new grounding line locations, leading to much improved estimates of ice thickness from ICESat surface profiles. Thickness is validated using airborne ground penetrating radar data where available.

  20. Springtime winds drive Ross Sea ice variability and change in the following autumn.

    PubMed

    Holland, Marika M; Landrum, Laura; Raphael, Marilyn; Stammerjohn, Sharon

    2017-09-28

    Autumn sea ice trends in the western Ross Sea dominate increases in Antarctic sea ice and are outside the range simulated by climate models. Here we use a number of independent data sets to show that variability in western Ross Sea autumn ice conditions is largely driven by springtime zonal winds in the high latitude South Pacific, with a lead-time of 5 months. Enhanced zonal winds dynamically thin the ice, allowing an earlier melt out, enhanced solar absorption, and reduced ice cover the next autumn. This seasonal lag relationship has implications for sea ice prediction. Given a weakening trend in springtime zonal winds, this lagged relationship can also explain an important fraction of the observed sea ice increase. An analysis of climate models indicates that they simulate weaker relationships and wind trends than observed. This contributes to weak western Ross Sea ice trends in climate model simulations.Antarctic sea ice extent continues to increase, with autumn sea ice advances in the western Ross Sea particularly anomalous. Here, based on analysis of independent datasets, the authors show that springtime zonal winds in the high latitude South Pacific drive western Ross Sea autumn sea ice conditions.

  1. Fluvial Instability and Channel Degradation of Amite River and its Tributaries, Southwest Mississippi and Southeast Louisiana

    DTIC Science & Technology

    2007-09-01

    48 Figure 64. Clearcutting ( deforestation ) of the riparian buffer between the Amite River and adjacent...and include land-use/land-cover changes and local engineered changes. Changes in land-use or land-cover include urbanization, deforestation and...diversity, reduced productivity, and extirpation or complete extinction of certain faunal groups (Hartfield 1988; Patrick, Ross, and Hartfield 1994

  2. The vascular plant flora of Hopewell Culture National Historical Park. Ross County, Ohio

    USGS Publications Warehouse

    Bennett, J.P.; Course, J.E.

    1996-01-01

    HopewellCulture National Historical Park, a unit of the United States National Park Service located in Ross County in south central Ohio, was created to restore, protect, and interpret the legacy of the mound building Hopewell prehistoric peoples. The vascular flora of the park had been estimated to be only 20% known prior to the undertaking of this project. During the spring, summer, and fall of 1995, almost 700 plant specimens were collected by three investigators from five units of the park. Totals of 438 species, 281 genera, and 93 families of vascular plants were discovered, representing 40% of the flora of Ross County, and 17% of the flora of Ohio. Introduced species constituted 32% of the flora. Sixty-five species are new records for Ross County. Two species of special concern, Spiranthes ovalis and Eleocharis ovata, are on the state's threatened and endangered species list. The Hopewell unit had the highest plant diversity of the five units.

  3. ‘Bellography’: Life and Contributions of Ross and Joyce Bell, two New England Naturalists

    PubMed Central

    Spence, John R.; Ball, George E.; Davidson, Robert L.; Rykken, Jessica J.

    2011-01-01

    Abstract The lives and contributions of Ross and Joyce Bell are described with particular attention to studies of invertebrate natural history in the state of Vermont and carabid beetles of several groups, including the world rhysodine fauna. Their work, all done at the University of Vermont, was mainly taxonomic in nature and included aspects of the biology of the species considered. During their careers they described more than 75% of the c. 340 rhysodine species known to science. Ross Bell also wrote a number of seminal papers about the basal relationships of the Adephaga and the comparative anatomy of carabid coxal cavities. Ross and Joyce inspired several generations of students at UVM to take up advanced work in entomology and natural history. PMID:22371660

  4. Paleobathymetric Reconstruction of Ross Sea: seismic data processing and regional reflectors mapping

    NASA Astrophysics Data System (ADS)

    Olivo, Elisabetta; De Santis, Laura; Wardell, Nigel; Geletti, Riccardo; Busetti, Martina; Sauli, Chiara; Bergamasco, Andrea; Colleoni, Florence; Vanzella, Walter; Sorlien, Christopher; Wilson, Doug; De Conto, Robert; Powell, Ross; Bart, Phil; Luyendyk, Bruce

    2017-04-01

    PURPOSE: New maps of some major unconformities of the Ross Sea have been reconstructed, by using seismic data grids, combined with the acoustic velocities from previous works, from new and reprocessed seismic profiles. This work is carried out with the support of PNRA and in the frame of the bilateral Italy-USA project GLAISS (Global Sea Level Rise & Antarctic Ice Sheet Stability predictions), funded by the Ministry of Foreign Affairs. Paleobathymetric maps of 30, 14 and 4 million years ago, three 'key moments' for the glacial history of the Antarctic Ice Sheet, coinciding with global climatic changes. The paleobathymetric maps will then be used for numeric simulations focused on the width and thickness of the Ross Sea Ice Sheet. PRELIMINARY RESULTS: The first step was to create TWT maps of three main unconformity (RSU6, RSU4, and RSU2) of Ross Sea, revisiting and updating the ANTOSTRAT maps, through the interpretation of sedimentary bodies and erosional features, used to infer active or old processes along the slope, we identified the main seismic unconformities. We used the HIS Kingdom academic license. The different groups contribution was on the analysis of the Eastern Ross Sea continental slope and rise (OGS), of the Central Basin (KOPRI) of the western and central Ross Sea (Univ. of Santa Barbara and OGS), where new drill sites and seismic profiles were collected after the publication of the ANTOSTRAT maps. Than we joined our interpretation with previous interpretations. We examined previous processing of several seismic lines and all the old acoustic velocity analysis. In addiction we reprocessed some lines in order to have a higher data coverage. Then, combining the TWT maps of the unconformity with the old and new speed data we created new depth maps of the study area. The new depth maps will then be used for reconstructing the paleobathymetry of the Ross Sea by applying backstripping technique.

  5. Identifying the role of reactive oxygen species (ROSs) in Fusarium solani spores inactivation.

    PubMed

    Du, Yilin; Xiong, Houfeng; Dong, Shuangshi; Zhang, Jun; Ma, Dongmei; Zhou, Dandan

    2016-12-01

    The inactivation mechanism of photocatalytic disinfectants on bacteria is well known. In contrast, the potential inactivation of fungal spores by visible-light induced photocatalysis has been recognized, but the inactivation mechanism is poorly understood. We hypothesize that photocatalytically generated reactive oxygen species (ROSs) are directly involved in this mechanism. To test this hypothesis, we identified the roles of ROSs in the inactivation of Fusarium solani spores. As the photocatalysts, we doped TiO2 with 3 typical dopants, forming Ag/TiO2, N/TiO2 and Er(3+):YAlO3/TiO2. The Ag/TiO2 photocatalysis was dominated by H2O2, with the longest lifetime among the investigated ROSs. Ag/TiO2 photocatalysis yielded almost 100 % inactivation efficiency and preserved the cell-wall shape of the spores, thus minimizing the biomolecule leakage. Er(3+):YAlO3/TiO2 was dominated by h(+) ROSs, yielding an inactivation efficiency of 91 %; however, the severe leakage released large numbers of molecular bio-products. Severe damage to the cell walls by the h(+) species was confirmed in micrograph observations. Subsequent to cell wall breakage, the Er(3+):YAlO3/TiO2 nanoparticles entered the spore cells and directly oxidized the intracellular material. The N/TiO2 photocatalysis, with •O2(-) dominated ROSs, delivered intermediate performance. In conclusion, photocatalysts that generate H2O2-dominated ROSs are most preferred for spore inactivation.

  6. The role of thermal and mechanical processes in the formation of the Ross Sea summer polynya

    NASA Astrophysics Data System (ADS)

    Reddy, Tasha E.; Arrigo, Kevin R.; Holland, David M.

    2007-07-01

    Three decades of satellite observations collected during spring and early summer have shown a recurring region of ice-free water forming in the sea-ice cover of the Ross Sea, Antarctica. This Ross Sea summer polynya plays an important role in heat exchange between the ocean and atmosphere, ventilation of deep water, and is characterized by high biological productivity. Despite its appearance each year, the relative importance of different physical processes to its formation and maintenance are not widely agreed upon. Here we use a three-dimensional coupled ice/ocean model to better understand processes controlling the dynamics of the Ross Sea polynya. Results from the model control run agree favorably with satellite microwave imagery of sea ice. Model sensitivity studies suggest that polynya dynamics are insensitive to the amount of snowfall, the presence of the Ross Ice Shelf cavity, tides, and solar radiation penetrating the ice. The model results also corroborate earlier findings that both the advection of sea ice and heat entrainment from warm Modified Circumpolar Deep Water play a role in Ross Sea polynya development. More importantly, the model further demonstrates that advection of sea ice due to wind stress plays the primary role in summer polynya formation. Additionally, we suggest that (1) heat entrainment reduces the rate of sea ice formation rather than melts existing sea ice, and (2) advection of sea ice due to synoptic wind events associated with variations in atmospheric pressure are the processes primarily responsible for the formation and expansion of the Ross Sea summer polynya.

  7. 78 FR 12357 - Brockway Mould, Inc., a Division of Ross International Ltd. Including Robert Lerch From BJR...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-22

    ... Employment and Training Administration Brockway Mould, Inc., a Division of Ross International Ltd. Including... Brockway Mould, Inc., a division of Ross International Ltd, Brockport, Pennsylvania (subject firm). The...,862 is hereby issued as follows: ``All workers from Brockway Mould, Inc., a division of...

  8. The M51 mystery: Lord Rosse, Robinson, South and the discovery of spiral structure in 1845

    NASA Astrophysics Data System (ADS)

    Steinicke, Wolfgang

    2012-03-01

    In April 1845 Lord Rosse discovered the spiral structure of M51 with his 72-inch reflector at Birr Castle. Already in March the new telescope had been pointed at the object in Canes Venatici, later nicknamed the 'Whirlpool Nebula'. Two experienced astronomers were present: Sir James South and the Reverend Thomas Romney Robin-son. The problem is that there is no record that they noticed the spiral structure, even though it was immediately seen by Lord Rosse the next month. The solution presented here is based on evidentiary facts, highlighting the nineteenth century astronomical praxis. Focal points are bias, fantasy and a sometimes fatal conspiracy of eye and brain.

  9. Barometric effects on tabular iceberg drift in the Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Turnbull, Ian D.

    The Inverse Barometer Effect (IBE) was observed in the nineteenth century by Sir James Clark Ross (Ross, 1854a), as deviations in sea-surface elevation in response to deviations in atmospheric pressure. This effect embodies the inverse relationship between sea-surface height (relative to long-term mean sea level) and atmospheric surface pressure. This thesis addresses the hypothesis that icebergs in the Ross Sea region of Antarctica are influenced by the same forces that create the IBE. This hypothesis is motivated by studies of icebergs in the Ross Sea, where drift data suggest that icebergs are drawn into temporary holding zones, or "Iceberg Parking Lots" situated where the surface pressure tends to display persistent, annual average low pressure. A physical explanation for the IBE's influence on icebergs is that they are often able to travel up the sea-surface slope induced by the IBE below atmospheric lows against the gravitational pull because of the pressure gradient force of the atmosphere acting on the iceberg's freeboard (the part of the iceberg that is above the waterline). Here, I evaluate the validity of the hypothesized IBE-iceberg relationship using a combined approach of data analysis and modeling. I have examined atmospheric surface pressure and wind records taken directly from the surfaces of four Ross Sea icebergs---B15A, B15K, C16, and B15J, and I have also built, and experimented with, models that predict iceberg drift response to atmospheric surface pressure and surface winds, using observed pressures and winds from B15A and B15J as model forcing. I additionally performed various experiments on a large, idealized tabular iceberg's physical sensitivity to the IBE using a model that treats atmospheric pressure and winds in an idealized, theoretical manner. I discovered that the IBE is indeed a significant influence on iceberg drift in and around Lewis Bay, just to the north of Ross Island, which will further our understanding of these icebergs

  10. STS-88 Mission Specialist Jerry L. Ross suits up for TCDT

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-88 Mission Specialist Jerry L. Ross (right) suits up in the Operations and Checkout Building, as part of a flight crew equipment fit check, prior to his trip to Launch Pad 39A. He is helped by suit tech Leonard Groce II. The STS-88 crew is at KSC to participate in the Terminal Countdown Demonstration Test (TCDT) which includes mission familiarization activities, emergency egress training, and a simulated launch countdown. This is Ross' sixth space flight. Mission STS-88 is targeted for launch on Dec. 3, 1998. It is the first U.S. flight for the assembly of the International Space Station and will carry the Unity connecting module.

  11. Holocene elephant seal distribution implies warmer-than-present climate in the Ross Sea.

    PubMed

    Hall, B L; Hoelzel, A R; Baroni, C; Denton, G H; Le Boeuf, B J; Overturf, B; Töpf, A L

    2006-07-05

    We show that southern elephant seal (Mirounga leonina) colonies existed proximate to the Ross Ice Shelf during the Holocene, well south of their core sub-Antarctic breeding and molting grounds. We propose that this was due to warming (including a previously unrecognized period from approximately 1,100 to 2,300 (14)C yr B.P.) that decreased coastal sea ice and allowed penetration of warmer-than-present climate conditions into the Ross Embayment. If, as proposed in the literature, the ice shelf survived this period, it would have been exposed to environments substantially warmer than present.

  12. Sea ice and oceanic processes on the Ross Sea continental shelf

    NASA Technical Reports Server (NTRS)

    Jacobs, S. S.; Comiso, J. C.

    1989-01-01

    The spatial and temporal variability of Antarctic sea ice concentrations on the Ross Sea continental shelf have been investigated in relation to oceanic and atmospheric forcing. Sea ice data were derived from Nimbus 7 scanning multichannel microwave radiometer (SMMR) brightness temperatures from 1979-1986. Ice cover over the shelf was persistently lower than above the adjacent deep ocean, averaging 86 percent during winter with little month-to-month of interannual variability. The large spring Ross Sea polynya on the western shelf results in a longer period of summer insolation, greater surface layer heat storage, and later ice formation in that region the following autumn.

  13. On the quasi-stationary distribution of the Ross malaria model.

    PubMed

    Nåsell, I

    1991-12-01

    Approximations are derived for the quasi-stationary distribution of the fully stochastic version of the classical Ross malaria model. The approximations are developed in two stages. In the first stage, the Ross process is approximated with a bivariate Markov chain without an absorbing state. The second stage of the approximation uses ideas from perturbation theory to derive explicit expressions that serve as approximations of the joint stationary distribution of the approximating process. Numerical comparisons are made between the approximations and the quasi-stationary distribution.

  14. STS-37 MS Godwin balances MS Ross using her index finger on OV-104's middeck

    NASA Image and Video Library

    1991-04-11

    STS037-29-002 (5-11 April 1991) --- Astronauts Linda M. Godwin and Jerry L. Ross perform a balancing act on Atlantis' middeck. With little effort Godwin is able to hold Ross up near the ceiling with her index finger. Although the area the two occupy is very small, a number of articles are seen, including two sleep restraints, the escape pole and Bioserve ITA Materials Dispersion Apparatus bioprocessing test bed (attached to stowage lockers at left). This was one of the visuals used by the STS-37 crewmembers during their April 19 post-flight press conference at the Johnson Space Center (JSC).

  15. James Ross Island captured by NASA photographer James Ross, from NASA's DC-8 aircraft during an AirSAR 2004 mission over the Antarctic Peninsula

    NASA Image and Video Library

    2004-03-16

    James Ross Island captured by NASA photographer James Ross(no relation), from NASA's DC-8 aircraft during an AirSAR 2004 mission over the Antarctic Peninsula. James Ross Island, named for 19th century British polar explorer Sir James Clark Ross, is located at the northern tip of the Antarctic Peninsula. The island is about 1500 m high and 40-60 km wide. In recent decades, the area has experienced significant atmospheric warming (about 2 degrees C since 1950), which has triggered a vast and spectacular retreat of its floating ice shelves, glacier reduction, a decrease in permanent snow cover and a lengthening of the melt season. AirSAR 2004 is a three-week expedition in Central and South America by an international team of scientists that is using an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR), located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world are combining ground research with NASA's AirSAR technology to improve and expand on the quality of research they are able to conduct. These photos are from the DC-8 aircraft while flying an AirSAR mission over Antarctica. The Antarctic Peninsula is more similar to Alaska and Patagonia than to the rest of the Antarctic continent. It is drained by fast glaciers, receives abundant precipitation, and melts significantly in the summer months. This region is being studied by NASA using a DC-8 equipped with the Airborne Synthetic Aperture Radar developed by scientists from NASA’s Jet Propulsion Laboratory. AirSAR will provide a baseline model and unprecedented mapping of the region. This data will make it possible to determine whether the warming trend is slowing, continuing or accelerating. AirSAR will also provide reliable information on ice shelf thickness to measure the contribution of the glaciers to sea level.

  16. Photographer: Digital Telepresence: Dr Murial Ross's Virtual Reality Application for Neuroscience

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Photographer: Digital Telepresence: Dr Murial Ross's Virtual Reality Application for Neuroscience Research Biocomputation. To study human disorders of balance and space motion sickness. Shown here is a 3D reconstruction of a nerve ending in inner ear, nature's wiring of balance organs.

  17. Bursch, Ross and Smith talk in Zvezda during STS-110's visit to the ISS

    NASA Image and Video Library

    2002-04-09

    STS110-E-5122 (10 April 2002) --- Astronauts Daniel W. Bursch (left), Expedition Four flight engineer, Jerry L. Ross and Steven L. Smith, both STS-110 mission specialists, converse in the Zvezda Service Module on the International Space Station (ISS). The image was taken with a digital still camera.

  18. Astronauts Ross and Helms at CAPCOM station during STS-61 simulations

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Astronauts Jerry L. Ross and Susan J. Helms are pictured at the Spacecraft Communicators console during joint integrated simulations for the STS-61 mission. Astronauts assigned to extravehicular activity (EVA) tasks with the Hubble Space Telescope (HST) were simultaneously rehearsing in a neutral buoyancy tank at the Marshall Space Flight Center (MSFC) in Alabama.

  19. Ross In Situ Uranium Recovery Project NESHAP Subpart W Construction Approval

    EPA Pesticide Factsheets

    On May 5, 2015, EPA issued a Construction Approval under the National Emission Standards for Hazardous Air Pollutants (NESHAPs) at 40 CFR Part 61, subpart W, to Strata Energy, Inc., for their Ross In Situ Recovery (ISR) Uranium Project in Crook County, WY.

  20. A Q-Methodological Study of the Kubler-Ross Stage Theory.

    ERIC Educational Resources Information Center

    Metzger, Anne M.

    1979-01-01

    Investigated the correspondence between stage changes hypothesized by the Kubler-Ross theory and the perception of the course of illness by seriously ill patients and their spouses. Supported the use of Q-methodology as a research procedure for investigations of terminal illness. (Author)

  1. Photographer: Digital Telepresence: Dr Murial Ross's Virtual Reality Application for Neuroscience

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Photographer: Digital Telepresence: Dr Murial Ross's Virtual Reality Application for Neuroscience Research Biocomputation. To study human disorders of balance and space motion sickness. Shown here is a 3D reconstruction of a nerve ending in inner ear, nature's wiring of balance organs.

  2. STS-37 Mission Specialist (MS) Ross during simulation in JSC's FB-SMS

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-37 Mission Specialist (MS) Jerry L. Ross 'borrows' the pilots station to rehearse some of his scheduled duties for his upcoming mission. He is on the flight deck of the fixed-based (FB) shuttle mission simulator (SMS) during this unsuited simulation. The SMS is part of JSC's Mission Simulation and Training Facility Bldg 5.

  3. Nest morphology and body size of Ross' Geese and Lesser Snow Geese

    USGS Publications Warehouse

    McCracken, K.G.; Afton, A.D.; Alisauskas, R.T.

    1997-01-01

    Arctic-nesting geese build large, insulated nests to protect developing embryos from cold ambient temperatures. Ross' Geese (Chen rossii) are about two-thirds the mass of Lesser Snow Geese (C. caerulescens caerulescens), have higher mass-specific metabolic rate, and maintain lower nest attentiveness, yet they hatch goslings with more functionally mature gizzards and more protein for their size than do Lesser Snow Geese. We compared nest size (a reflection of nest insulation) in four distinct habitats in a mixed breeding colony of Ross' Geese and Lesser Snow Geese at Karrak Lake, Northwest Territories, Canada. After adjusting measurements for nest-specific egg size and clutch size, we found that overall nest morphology differed between species and among habitats. Nest size increased progressively among heath, rock, mixed, and moss habitats. When nesting materials were not limiting, nests were smaller in habitats that provided cover from wind and precipitation than in habitats that did not provide cover. Ross' Geese constructed relatively larger, more insulated nests than did Lesser Snow Geese, which may hasten embryonic development, minimize energy expenditure during incubation, and minimize embryonic cooling during recesses. We suggest that relative differences in nest morphology reflect greater selection for Ross' Geese to improve nest insulation because of their smaller size (adults and embryos), higher mass-specific metabolic rate, and lower incubation constancy.

  4. A Q-Methodological Study of the Kubler-Ross Stage Theory.

    ERIC Educational Resources Information Center

    Metzger, Anne M.

    1979-01-01

    Investigated the correspondence between stage changes hypothesized by the Kubler-Ross theory and the perception of the course of illness by seriously ill patients and their spouses. Supported the use of Q-methodology as a research procedure for investigations of terminal illness. (Author)

  5. Ross procedure in a child with Aspergillus endocarditis and bicuspid aortic valve.

    PubMed

    Mitropoulos, Fotios A; Kanakis, Meletios A; Contrafouris, Constantinos; Laskari, Cleo; Rammos, Spyridon; Apostolidis, Christos; Azariadis, Prodromos; Chatzis, Andrew C

    2014-08-23

    The case is presented of a previously healthy infant with a known asymptomatic bicuspid aortic valve who developed fungal endocarditis. The patient underwent aortic root replacement with a pulmonary autograft (Ross procedure). Cultured operative material revealed Aspergillus infection. The patient had an excellent recovery and remained well one year later.

  6. A Helping Hand in the Frederick Community—Ross Smith | Poster

    Cancer.gov

    By day, Ross Smith is the compliance and security officer for Data Management Services, Inc., assigned to the National Cancer Institute (NCI) at Frederick. His role is to ensure the secure operation of in-house computer systems, servers, and network connections. But in his spare time, Smith is also a volunteer firefighter and emergency medical technician (EMT).

  7. California State Waters Map Series—Offshore of Fort Ross, California

    USGS Publications Warehouse

    Johnson, Samuel Y.; Dartnell, Peter; Golden, Nadine E.; Hartwell, Stephen R.; Erdey, Mercedes D.; Greene, H. Gary; Cochrane, Guy R.; Kvitek, Rikk G.; Manson, Michael W.; Endris, Charles A.; Dieter, Bryan E.; Watt, Janet T.; Krigsman, Lisa M.; Sliter, Ray W.; Lowe, Erik N.; Chin, John L.; Johnson, Samuel Y.; Cochran, Susan A.

    2015-12-03

    Potential marine benthic habitat types in the Offshore of Fort Ross map area include unconsolidated continental-shelf sediments, mixed continental-shelf substrate, and hard continental-shelf substrate. Rocky shelf outcrops and rubble are considered the primary habitat type for rockfish and lingcod, both of which are recreationally and commercially important species.

  8. REM/ROSS: a powerful tool for monitoring the prompt afterglow of γ-ray bursts

    NASA Astrophysics Data System (ADS)

    Tagliaferri, G.; Zerbi, F. M.; Chincarini, G.; Ghisellini, G.; Rodonò, M.; Palazzi, E.; Antonelli, L. A.; Conconi, P.; Covino, S.; Cutispoto, G.; Molinari, E.; Nicastro, L.; Tosti, G.; REM/ROSS Team

    2004-01-01

    Observations of the prompt afterglow of γ-ray burst events are unanimously considered of paramount importance for GRB science and cosmology. Such observations at NIR wavelengths are even more promising allowing the monitoring of high- z Ly-α absorbed bursts as well as events occurring in dusty star-forming regions. In these pages we present rapid eye mount (REM), a fully robotized fast slewing telescope equipped with a high throughput NIR (Z, J, H, K) camera dedicated to detecting the prompt IR afterglow. REM can discover objects at extremely high redshift and trigger large telescopes to observe them. The REM telescope will simultaneously feed REM optical slitless spectrograph (ROSS) via a dichroic. ROSS will intensively monitor the prompt optical continuum of GRB afterglows. The synergy between the REM-IR camera and the ROSS spectrograph makes REM a powerful observing tool for any kind of fast transient phenomena. Beside its ambitious scientific goals, REM is also technically challenging since it represent the first attempt to locate a NIR camera on a small telescope providing, with ROSS, unprecedented simultaneous wavelength coverage on a telescope of this size.

  9. Overflow dynamics and bottom water formation in the western Ross Sea: Influence of tides

    NASA Astrophysics Data System (ADS)

    Wang, Q.; Danilov, S.; Hellmer, H. H.; SchröTer, J.

    2010-10-01

    The tidal impact on overflow dynamics and bottom water production in the western Ross Sea is studied with the Finite Element Ocean Model, which allows embedding a mesh with 0.5 km resolution in a coarse resolution (30 km) setup without nesting. The simulated overflow properties inside and downstream of the western Ross Sea are described. The overflow exhibits pronounced variability at both daily and spring-neap tidal time scales in the western Ross Sea. Tides increase mixing over both the outer shelf and upper slope there. Plume jets are shaped by tidal currents at a bathymetric bend west of the Drygalski Trough mouth, descending rapidly and supplying the bottom water. A fraction of shelf water remains over the shelf and propagates westward from the Ross Sea, but it does not contribute significantly to bottom water formation because of energetic mixing over the upper slope. Compared to a simulation without tidal forcing, tides (with the major K1 and O1 constituents) increase the outflow rate over the continental slope off Cape Adare by about 70%. A set of sensitivity experiments show that the rate of bottom water production is not a monotonic function of the tidal currents amplitude. Tidal forcing with intermediate strength leads to the most efficient bottom water formation.

  10. STS-37 Mission Specialist (MS) Ross during simulation in JSC's FB-SMS

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-37 Mission Specialist (MS) Jerry L. Ross 'borrows' the pilots station to rehearse some of his scheduled duties for his upcoming mission. He is on the flight deck of the fixed-based (FB) shuttle mission simulator (SMS) during this unsuited simulation. The SMS is part of JSC's Mission Simulation and Training Facility Bldg 5.

  11. Astronauts Ross and Helms at CAPCOM station during STS-61 simulations

    NASA Image and Video Library

    1993-09-01

    S93-43752 (1 Sept 1993) --- Astronauts Jerry L. Ross and Susan J. Helms are pictured at the Spacecraft Communicators Console during joint integrated simulations for the STS-61 mission. Astronauts assigned to extravehicular activity (EVA) tasks with the Hubble Space Telescope (HST) were simultaneously rehearsing in a Neutral Buoyancy Simulator (NBS) tank at the Marshall Space Flight Center (MSFC) in Alabama.

  12. A Helping Hand in the Frederick Community—Ross Smith | Poster

    Cancer.gov

    By day, Ross Smith is the compliance and security officer for Data Management Services, Inc., assigned to the National Cancer Institute (NCI) at Frederick. His role is to ensure the secure operation of in-house computer systems, servers, and network connections. But in his spare time, Smith is also a volunteer firefighter and emergency medical technician (EMT).

  13. Two Case Histories, Ishbel Ross and Emma Bugbee: Women Journalists Ride the Rail with the Suffragettes.

    ERIC Educational Resources Information Center

    Merrick, Beverly G.

    The rise to prominence of the women's suffrage movement in the World War I years brought women reporters into U.S. newsrooms for the first time. In 1911 Emma Bugbee became the first woman hired as a "hard" news reporter for the "New York Tribune" (later the "Herald Tribune"). Ishbel Ross, author of "Ladies of the…

  14. Distribution and ventilation of water masses in the western Ross Sea inferred from CFC measurements

    NASA Astrophysics Data System (ADS)

    Rivaro, Paola; Ianni, Carmela; Magi, Emanuele; Massolo, Serena; Budillon, Giorgio; Smethie, William M.

    2015-03-01

    During the CLIMA Project (R.V. Italica cruise PNRA XVI, January-February 2001), hydrographic and chlorofluorocarbons (CFCs) observations were obtained, particularly in the western Ross Sea. Their distribution demonstrated water mass structure and ventilation processes in the investigated areas. In the surface waters (AASW) the CFC saturation levels varied spatially: CFCs were undersaturated in all the areas (range from 80 to 90%), with the exception of few stations sampled near Ross Island. In particular, the Terra Nova Bay polynya, where high salinity shelf water (HSSW) is produced, was a low-saturated surface area (74%) with respect to CFCs. Throughout most of the shelf area, the presence of modified circumpolar deep water (MCDW) was reflected in a mid-depth CFC concentration minima. Beneath the MCDW, CFC concentrations generally increased in the shelf waters towards the seafloor. We estimated that the corresponding CFCs saturation level in the source water region for HSSW was about 68-70%. Waters with high CFC concentrations were detected in the western Ross Sea on the down slope side of the Drygalski Trough, indicating that AABW was being supplied to the deep Antarctic Basin. Estimates of ventilation ages depend strongly on the saturation levels. We calculated ventilation ages using the saturation level calibrated tracer ratio, CFC11/CFC12. We deduced a mean residence time of the shelf waters of about 6-7 years between the western Ross Sea source and the shelf break.

  15. Temporal progression of photosynthetic-strategy in phytoplankton in the Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Ryan-Keogh, Thomas J.; DeLizo, Liza M.; Smith, Walker O.; Sedwick, Peter N.; McGillicuddy, Dennis J.; Moore, C. Mark; Bibby, Thomas S.

    2017-02-01

    The bioavailability of iron influences the distribution, biomass and productivity of phytoplankton in the Ross Sea, one of the most productive regions in the Southern Ocean. We mapped the spatial and temporal extent and severity of iron-limitation of the native phytoplankton assemblage using long- (> 24 h) and short-term (24 h) iron-addition experiments along with physiological and molecular characterisations during a cruise to the Ross Sea in December-February 2012. Phytoplankton increased their photosynthetic efficiency in response to iron addition, suggesting proximal iron limitation throughout most of the Ross Sea during summer. Molecular and physiological data further indicate that as nitrate is removed from the surface ocean the phytoplankton community transitions to one displaying an iron-efficient photosynthetic strategy characterised by an increase in the size of photosystem II (PSII) photochemical cross section (σPSII) and a decrease in the chlorophyll-normalised PSII abundance. These results suggest that phytoplankton with the ability to reduce their photosynthetic iron requirements are selected as the growing season progresses, which may drive the well-documented progression from Phaeocystis antarctica- assemblages to diatom-dominated phytoplankton. Such a shift in the assemblage-level photosynthetic strategy potentially mediates further drawdown of nitrate following the development of iron deficient conditions in the Ross Sea.

  16. Atmospheric forcing of sea ice anomalies in the Ross Sea polynya region

    NASA Astrophysics Data System (ADS)

    Dale, Ethan R.; McDonald, Adrian J.; Coggins, Jack H. J.; Rack, Wolfgang

    2017-01-01

    We investigate the impacts of strong wind events on the sea ice concentration within the Ross Sea polynya (RSP), which may have consequences on sea ice formation. Bootstrap sea ice concentration (SIC) measurements derived from satellite SSM/I brightness temperatures are correlated with surface winds and temperatures from Ross Ice Shelf automatic weather stations (AWSs) and weather models (ERA-Interim). Daily data in the austral winter period were used to classify characteristic weather regimes based on the percentiles of wind speed. For each regime a composite of a SIC anomaly was formed for the entire Ross Sea region and we found that persistent weak winds near the edge of the Ross Ice Shelf are generally associated with positive SIC anomalies in the Ross Sea polynya and vice versa. By analyzing sea ice motion vectors derived from the SSM/I brightness temperatures we find significant sea ice motion anomalies throughout the Ross Sea during strong wind events, which persist for several days after a strong wind event has ended. Strong, negative correlations are found between SIC and AWS wind speed within the RSP indicating that strong winds cause significant advection of sea ice in the region. We were able to partially recreate these correlations using colocated, modeled ERA-Interim wind speeds. However, large AWS and model differences are observed in the vicinity of Ross Island, where ERA-Interim underestimates wind speeds by a factor of 1.7 resulting in a significant misrepresentation of RSP processes in this area based on model data. Thus, the cross-correlation functions produced by compositing based on ERA-Interim wind speeds differed significantly from those produced with AWS wind speeds. In general the rapid decrease in SIC during a strong wind event is followed by a more gradual recovery in SIC. The SIC recovery continues over a time period greater than the average persistence of strong wind events and sea ice motion anomalies. This suggests that sea ice

  17. Coastal-change and glaciological map of the Ross Island area, Antarctica

    USGS Publications Warehouse

    Ferrigno, Jane G.; Foley, Kevin M.; Swithinbank, Charles; Williams, Richard S.

    2010-01-01

    Reduction in the area and volume of Earth?s two polar ice sheets is intricately linked to changes in global climate and to the resulting rise in sea level. Measurement of changes in area and mass balance of the Antarctic ice sheet was given a very high priority in recommendations by the Polar Research Board of the National Research Council. On the basis of these recommendations, the U.S. Geological Survey used its archive of satellite images to document changes in the cryospheric coastline of Antarctica and analyze the glaciological features of the coastal regions. The Ross Island area map is bounded by long 141? E. and 175? E. and by lat 76? S. and 81? S. The map covers the part of southern Victoria Land that includes the northwestern Ross Ice Shelf, the McMurdo Ice Shelf, part of the polar plateau and Transantarctic Mountains, the McMurdo Dry Valleys, northernmost Shackleton Coast, Hillary Coast, the southern part of Scott Coast, and Ross Island. Little noticeable change has occurred in the ice fronts on the map, so the focus is on glaciological features. In the western part of the map area, the polar plateau of East Antarctica, once thought to be a featureless region, has subtle wavelike surface forms (megadunes) and flow traces of glaciers that originate far inland and extend to the coast or into the Ross Ice Shelf. There are numerous outlet glaciers. Glaciers drain into the McMurdo Dry Valleys, through the Transantarctic Mountains into the Ross Sea, or into the Ross Ice Shelf. Byrd Glacier is the largest. West of the Transantarctic Mountains are areas of blue ice, readily identifiable on Landsat images, that have been determined to be prime areas for finding meteorites. Three subglacial lakes have been identified in the map area. Because McMurdo Station, the main U.S. scientific research station in Antarctica, is located on Ross Island in the map area, many of these and other features in the area have been studied extensively. The paper version of this map is

  18. Crustal Vp-Vs ratios and thickness for Ross Island and the Transantarctic Mountain front, Antarctica

    NASA Astrophysics Data System (ADS)

    Finotello, Marco; Nyblade, Andrew; Julia, Jordi; Wiens, Douglas; Anandakrishnan, Sridhar

    2011-04-01

    We investigate crustal Vp-Vs ratios and thickness along the Transantarctic Mountain (TAM) front and on Ross Island, Antarctica to determine if the TAM crust has been modified by the Neogene magmatism associated with Ross Island. A seismic low velocity zone (LVZ) in the upper mantle beneath Ross Island extends laterally ˜80 km under the TAM front, and mantle temperatures within the LVZ may be sufficiently elevated for partial melting to have occurred and modified the crust. Data for the study come from 16 temporary seismic stations that were part of the TAM Seismic Experiment and three permanent stations. Estimates of Vp/Vs (κ) and crustal thickness (H) have been obtained from receiver functions analysed using the H-κ stacking method for 10 of the stations, and for the remaining stations, crustal thickness has been calculated by using the Moho Ps arrival time with an assumed Vp/Vs value. A Vp/Vs value of 1.88 is obtained for Ross Island, consistent with the mafic composition of the volcanic rocks from Mt. Erebus. Vp/Vs values for stations in the TAM situated away from the LVZ range from 1.63 to 1.78, with a mean of 1.73, while values for stations in the TAM lying above the LVZ range from 1.67 to 1.78, with a mean of 1.72. This result indicates that there is little difference in bulk crustal composition for areas above and away from the LVZ, and together with a Vp/Vs value (1.73) that is typical for felsic to intermediate composition crust, suggests that the crust along the TAM front has not been altered significantly by mafic magmatism. Crustal thickness estimates along the coast are quite variable, ranging from 18 to 33 km, and increase to 39 km inland beneath the crest of the TAM. On Ross Island, crustal thickness estimates range between 19 and 27 km.

  19. The Scientific Papers of William Parsons, Third Earl of Rosse 1800-1867

    NASA Astrophysics Data System (ADS)

    Parsons, William; Parsons, Charles

    2011-11-01

    From the Edinburgh Journal of Science: 1. 1828. Account of a new reflecting telescope; 2. 1828. Account of an apparatus for grinding and polishing the specula of reflecting telescopes; 3. 1830. Account of a series of experiments on the construction of large reflecting telescopes; From the Proceedings of the Royal Irish Academy: 4. 1840. Account of the three-feet telescope T. R. Robinson; 5. 1845. On Lord Rosse's telescope T. R. Robinson; 6. 1848. On Lord Rosse's telescope T. R. Robinson; 7. 1848. Observation of the nebula, Herschel 44 T. R. Robinson; 8. 1848. Contents of an ancient bronze vessel, in the collection of the Earl of Rosse T. R. Robinson; From Reports of the British Association for the Advancement of Science: 9. 1843. Presidential address by the Earl of Rosse; 10. 1844. On the construction of large reflecting telescopes; 11. 1851. Plain specula of silver; 12. 1852. Drawings to illustrate recent observations on nebulae; 13. 1853. First report of the committee … on the physical characteristics of the Moon's surface; 14. 1857. Mechanical science; 15. 1859. Mathematics and physics; From Monthly Notices of the Royal Astronomical Society: 16. 1854. Notes on experiments relative to lunar photography and the construction of reflecting specula; 17. 1866. Description of an equatoreal clock; The Royal Society: 18. 1854. Address of the Rt. Hon. the Earl of Rosse; From the Philosophical Transactions of the Royal Society: 19. 1840. An account of experiments on the reflecting telescope; 20. 1844. Observations on some of the nebulae; 21. 1850. Observations on the nebulae; 22. 1861. On the construction of specula of six-feet aperture, and a selection from the observations of nebulae made with them; 23. 1867. An account of the observations on the great nebula in Orion, made at Birr Castle, with the 3-feet and 6-feet telescopes, between 1848 and 1867; Institution of Naval Architects: 24. 1854-65. A contribution to the history of ironclads.

  20. Widespread collapse of the Ross Ice Shelf during the late Holocene

    PubMed Central

    Yokoyama, Yusuke; Anderson, John B.; Yamane, Masako; Simkins, Lauren M.; Miyairi, Yosuke; Yamazaki, Takahiro; Koizumi, Mamito; Suga, Hisami; Kusahara, Kazuya; Prothro, Lindsay; Hasumi, Hiroyasu; Southon, John R.; Ohkouchi, Naohiko

    2016-01-01

    The stability of modern ice shelves is threatened by atmospheric and oceanic warming. The geologic record of formerly glaciated continental shelves provides a window into the past of how ice shelves responded to a warming climate. Fields of deep (−560 m), linear iceberg furrows on the outer, western Ross Sea continental shelf record an early post-Last Glacial Maximum episode of ice-shelf collapse that was followed by continuous retreat of the grounding line for ∼200 km. Runaway grounding line conditions culminated once the ice became pinned on shallow banks in the western Ross Sea. This early episode of ice-shelf collapse is not observed in the eastern Ross Sea, where more episodic grounding line retreat took place. More widespread (∼280,000 km2) retreat of the ancestral Ross Ice Shelf occurred during the late Holocene. This event is recorded in sediment cores by a shift from terrigenous glacimarine mud to diatomaceous open-marine sediment as well as an increase in radiogenic beryllium (10Be) concentrations. The timing of ice-shelf breakup is constrained by compound specific radiocarbon ages, the first application of this technique systematically applied to Antarctic marine sediments. Breakup initiated around 5 ka, with the ice shelf reaching its current configuration ∼1.5 ka. In the eastern Ross Sea, the ice shelf retreated up to 100 km in about a thousand years. Three-dimensional thermodynamic ice-shelf/ocean modeling results and comparison with ice-core records indicate that ice-shelf breakup resulted from combined atmospheric warming and warm ocean currents impinging onto the continental shelf. PMID:26884201

  1. Widespread collapse of the Ross Ice Shelf during the late Holocene.

    PubMed

    Yokoyama, Yusuke; Anderson, John B; Yamane, Masako; Simkins, Lauren M; Miyairi, Yosuke; Yamazaki, Takahiro; Koizumi, Mamito; Suga, Hisami; Kusahara, Kazuya; Prothro, Lindsay; Hasumi, Hiroyasu; Southon, John R; Ohkouchi, Naohiko

    2016-03-01

    The stability of modern ice shelves is threatened by atmospheric and oceanic warming. The geologic record of formerly glaciated continental shelves provides a window into the past of how ice shelves responded to a warming climate. Fields of deep (-560 m), linear iceberg furrows on the outer, western Ross Sea continental shelf record an early post-Last Glacial Maximum episode of ice-shelf collapse that was followed by continuous retreat of the grounding line for ∼200 km. Runaway grounding line conditions culminated once the ice became pinned on shallow banks in the western Ross Sea. This early episode of ice-shelf collapse is not observed in the eastern Ross Sea, where more episodic grounding line retreat took place. More widespread (∼280,000 km(2)) retreat of the ancestral Ross Ice Shelf occurred during the late Holocene. This event is recorded in sediment cores by a shift from terrigenous glacimarine mud to diatomaceous open-marine sediment as well as an increase in radiogenic beryllium ((10)Be) concentrations. The timing of ice-shelf breakup is constrained by compound specific radiocarbon ages, the first application of this technique systematically applied to Antarctic marine sediments. Breakup initiated around 5 ka, with the ice shelf reaching its current configuration ∼1.5 ka. In the eastern Ross Sea, the ice shelf retreated up to 100 km in about a thousand years. Three-dimensional thermodynamic ice-shelf/ocean modeling results and comparison with ice-core records indicate that ice-shelf breakup resulted from combined atmospheric warming and warm ocean currents impinging onto the continental shelf.

  2. Distribution, density, and abundance of pack-ice seals in the Amundsen and Ross Seas, Antarctica

    NASA Astrophysics Data System (ADS)

    Bengtson, John L.; Laake, Jeff L.; Boveng, Peter L.; Cameron, Michael F.; Bradley Hanson, M.; Stewart, Brent S.

    2011-05-01

    We made three sets of population surveys of the four species of ice-inhabiting phocid pinnipeds in the Ross and Amundsen Seas between 26 December 1999 and 24 March 2000 using icebreakers and helicopters deployed from those icebreakers. We used line transect methods to survey 23,671 km by helicopter and 3,694 km by ship accounting for a total coverage of 53,217 km 2. We detected and identified 11,308 seals in 7,104 groups and estimated their abundance from estimates of densities using distance sampling methods and corrections for probability of haul out of seals derived from satellite telemetry of tagged seals. Crabeater seals were most abundant (ca 1.7 million) followed by Weddell seals (330,000), Ross seals (22,600), and leopard seals (15,000). Our estimates of abundance are difficult to directly compare with earlier estimates because of geographic areas covered and by our improvements in survey and analytical methods. Notwithstanding these limitations and with some adjustments for differences in methods, we found that our estimates of abundance for crabeater seals are similar to those from the most recent surveys in the Ross and Amundsen Seas and along the George-Oates Coast. Our estimates for Weddell seals are the first for the broad areas of pack ice that we surveyed in the Ross and Amundsen Seas but indicate that these habitats are ecologically important to this species. Our estimates of abundance of Ross seals were relatively similar to estimates for surveys in these areas in the 1970s and 1980s whereas our estimates of abundance of leopard seals were substantially lower.

  3. Hemispheric atmospheric variations and oceanographic impacts associated with katabatic surges across the Ross Ice Shelf, Antarctica

    NASA Astrophysics Data System (ADS)

    Bromwich, David H.; Carrasco, Jorge F.; Liu, Zhong; Tzeng, Ren-Yow

    1993-07-01

    Numerical simulations and surface-based observations show that katabatic winds persistently converge toward and blow across the Siple Coast part of West Antarctica onto the Ross Ice Shelf. About 14% of the time during winter (April to August 1988), thermal infrared satellite images reveal the horizontal propagation of this negatively buoyant katabatic airstream for about 1000 km across the ice shelf to its northwestern edge, a trajectory that nearly parallels the Transantarctic Mountains. This takes place when the pressure field supports such airflow, and is caused by synoptic scale cyclones that decay near and/or over Marie Byrd Land. The northwestward propagation of the katabatic winds is accompanied by other changes in the hemispheric long wave pattern. An upper level ridge develops over Wilkes Land, resulting in an enhancement of the split jet in the Pacific Ocean. Then, more frequent and/or intensified synoptic scale cyclones are steered toward Marie Byrd Land where they become nearly stationary to the northeast of the climatological location. The resulting isobaric configuration accelerates the katabatic winds crossing Siple Coast and supports their horizontal propagation across the Ross Ice Shelf. An immediate impact of this katabatic airflow, that crosses from the ice shelf to the Ross Sea, is expansion of the persistent polynya that is present just to the east of Ross Island. This polynya is a conspicuous feature on passive microwave images of Antarctic sea ice and plays a central role in the salt budget of water masses over the Ross Sea continental shelf. The impact of this katabatic airflow upon mesoscale cyclogenesis over the South Pacific Ocean is also discussed.

  4. Air-sea Forcing and Thermohaline Changes In The Ross Sea.

    NASA Astrophysics Data System (ADS)

    Fusco, G.; Budillon, G.

    Heat exchanges between sea and atmosphere from 1986 to 2000 in the Ross Sea (Antarctica) were computed from climatological data obtained from the European Centre for Medium Range Weather Forecasts. They have been related with the thermo- haline changes observed during 5 hydrological surveys performed between the austral summer 1994-1995 and 2000-2001 in the western sector of the Ross Sea. The esti- mated heat fluxes show extremely strong spatial and temporal variability over all the Ross Sea. As can be expected the largest heat losses occur between May and August, while during the period November-February the heat budget becomes positive. In the first six years of the investigated period the heat loss is very strong with its maximum about 166 Wm-2; while during the period 1992-2000 the yearly heat losses are the lowest. Thermohaline changes in the surface layer (upper pycnocline) of the western Ross Sea follow the expected seasonal pattern of warming and freshening from the be- ginning to the end of the austral summer. The heating changes are substantially lower than the estimated heat supplied by the atmosphere during the summer, which under- lines the importance in this season of the advective component carried by the currents in the total heat budget of this area. The year to year differences are about one or two orders of magnitude smaller than the seasonal changes in the surface layer. In the in- termediate and deep layers, the summer heat and salt variability is of the same order as or one order higher than from one summer to the next. Moreover a freshening of the near bottom layer has been observed, it is consistent with the High Salinity Shelf Water salinity decrease recently detected in the Ross Sea.

  5. Large Trajectory Ensembles for understanding Snow Accumulation over the Ross Ice Shelf

    NASA Astrophysics Data System (ADS)

    Dale, Ethan; McDonald, Adrian; Rack, Wolfgang

    2017-04-01

    We investigate how differing synoptic weather patterns over Antarctica affect the rate of precipitation. During the 2015/16 field season a 16m firn core was drilled on the Ross Ice Shelf (80.7o S 174.5o E). Oxygen (δ18O) and Deuterium (δ2H) isotope analysis of this core allow a 40 year record of snow accumulation and therefore precipitation over the Ross Ice Shelf to be produced. The resulting precipitation record differs significantly in magnitude and trend from climate model precipitation over a similar period of time. In an effort to interpret this core we have attempted to identify distinctive weather patterns impacting snow accumulation. Lagrangian back trajectories are calculated from reanalysis wind fields to examine the origin of the air. The spatial distribution of trajectories as a function of time over the period of the ice core record are examined in an attempt to relate specific periods of large and small snow accumulation to particular pathways. We also examine how large scale modes of variability (Southern Annular Mode, El Nino Southern Oscillation and the Amundsen Sea Low) impact the spatial distribution of trajectories. Re-analysis humidity data along each trajectory is also considered allowing a more comprehensive identification of the origin of moist air, also helping to identify a representative 'residence time' of moisture for which our trajectory analysis is completed. Similar to previous studies we find that during periods of precipitation, air over the Ross Ice Shelf more frequently originates in the Ross and Amundsen Seas. While during dry periods over the Ross Ice Shelf we find the air originates more frequently from the Bellingshausen and Weddell seas, as well as continental Antarctica.

  6. Use of supplemental food by breeding Ross's Geese and Lesser Snow Geese: Evidence for variable anorexia

    USGS Publications Warehouse

    Gloutney, M.L.; Alisauskas, R.T.; Hobson, K.A.; Afton, A.D.

    1999-01-01

    Recent research suggests that foods eaten during laying and incubation play a greater role in supplying energy and nutrients to arctic-nesting geese than previously believed. We conducted food-supplementation experiments with Ross's Geese (Chen rossii) and Lesser Snow Geese (C. caerulescens) geese to evaluate: (1) if supplemental food was consumed by laying and incubating geese, (2) how food consumption influenced mass dynamics of somatic tissues of breeding geese, (3) if patterns of mass loss were consistent with fasting adaptations, and (4) whether energetic constraints would cause smaller Ross's Geese to consume more food relative to their body size than would larger Snow Geese. Quantity of supplemental food eaten by both species during laying and incubation was highly variable among individuals. Consumption of supplemental food during laying resulted in differences in overall body composition between control and treatment females. Treatment female Ross's Geese completed laying at a higher mass and with more abdominal fat than controls, whereas treatment female Snow Geese completed laying with heavier breast muscles and hearts. Overall body composition did not differ between control and treatment geese (both sexes and species) at the end of incubation, but treatment geese had heavier hearts than control geese. This suggests that treatment females did not rely to the same extent on metabolic adaptations associated with anorexia to meet energetic costs of incubation as did controls. Stable-nitrogen isotope analysis revealed patterns of protein maintenance during incubation consistent with metabolic adaptations to prolonged fasting. Our prediction that energetic constraints would cause smaller Ross's Geese to consume more food relative to their size than would Snow Geese was not supported. Mass-specific food consumption by Ross's Geese was 30% lower than that of Snow Geese during laying and 48% higher during incubation.

  7. Ross Sea paleo-ice sheet drainage and deglacial history during and since the LGM

    NASA Astrophysics Data System (ADS)

    Anderson, John B.; Conway, Howard; Bart, Philip J.; Witus, Alexandra E.; Greenwood, Sarah L.; McKay, Robert M.; Hall, Brenda L.; Ackert, Robert P.; Licht, Kathy; Jakobsson, Martin; Stone, John O.

    2014-09-01

    Onshore and offshore studies show that an expanded, grounded ice sheet occupied the Ross Sea Embayment during the Last Glacial Maximum (LGM). Results from studies of till provenance and the orientation of geomorphic features on the continental shelf show that more than half of the grounded ice sheet consisted of East Antarctic ice flowing through Transantarctic Mountain (TAM) outlet glaciers; the remainder came from West Antarctica. Terrestrial data indicate little or no thickening in the upper catchment regions in both West and East Antarctica during the LGM. In contrast, evidence from the mouths of the southern and central TAM outlet glaciers indicate surface elevations between 1000 m and 1100 m (above present-day sea level). Farther north along the western margin of the Ross Ice Sheet, surface elevations reached 720 m on Ross Island, and 400 m at Terra Nova Bay. Evidence from Marie Byrd Land at the eastern margin of the ice sheet indicates that the elevation near the present-day grounding line was more than 800 m asl, while at Siple Dome in the central Ross Embayment, the surface elevation was about 950 m asl. Farther north, evidence that the ice sheet was grounded on the middle and the outer continental shelf during the LGM implies that surface elevations had to be at least 100 m above the LGM sea level. The apparent low surface profile and implied low basal shear stress in the central and eastern embayment suggests that although the ice streams may have slowed during the LGM, they remained active. Ice-sheet retreat from the western Ross Embayment during the Holocene is constrained by marine and terrestrial data. Ages from marine sediments suggest that the grounding line had retreated from its LGM outer shelf location only a few tens of kilometer to a location south of Coulman Island by ˜13 ka BP. The ice sheet margin was located in the vicinity of the Drygalski Ice Tongue by ˜11 ka BP, just north of Ross Island by ˜7.8 ka BP, and near Hatherton Glacier by

  8. The Satellite Passive-Microwave Record of Sea Ice in the Ross Sea Since Late 1978

    NASA Technical Reports Server (NTRS)

    Parkinson, Claire L.

    2009-01-01

    Satellites have provided us with a remarkable ability to monitor many aspects of the globe day-in and day-out and sea ice is one of numerous variables that by now have quite substantial satellite records. Passive-microwave data have been particularly valuable in sea ice monitoring, with a record that extends back to August 1987 on daily basis (for most of the period), to November 1970 on a less complete basis (again for most of the period), and to December 1972 on a less complete basis. For the period since November 1970, Ross Sea sea ice imagery is available at spatial resolution of approximately 25 km. This allows good depictions of the seasonal advance and retreat of the ice cover each year, along with its marked interannual variability. The Ross Sea ice extent typically reaches a minimum of approximately 0.7 x 10(exp 6) square kilometers in February, rising to a maximum of approximately 4.0 x 10(exp 6) square kilometers in September, with much variability among years for both those numbers. The Ross Sea images show clearly the day-by-day activity greatly from year to year. Animations of the data help to highlight the dynamic nature of the Ross Sea ice cover. The satellite data also allow calculation of trends in the ice cover over the period of the satellite record. Using linear least-squares fits, the Ross Sea ice extent increased at an average rate of 12,600 plus or minus 1,800 square kilometers per year between November 1978 and December 2007, with every month exhibiting increased ice extent and the rates of increase ranging from a low of 7,500 plus or minus 5,000 square kilometers per year for the February ice extents to a high of 20,300 plus or minus 6,100 kilometers per year for the October ice extents. On a yearly average basis, for 1979-2007 the Ross Sea ice extent increased at a rate of 4.8 plus or minus 1.6 % per decade. Placing the Ross Sea in the context of the Southern Ocean as a whole, over the November 1978-December 2007 period the Ross Sea had

  9. Seismic stratigraphy of the Plio-Pleistocene Ross Island flexural moat-fill: a prognosis for ANDRILL Program drilling beneath McMurdo-Ross Ice Shelf

    NASA Astrophysics Data System (ADS)

    Horgan, H.; Naish, T.; Bannister, S.; Balfour, N.; Wilson, G.

    2005-02-01

    Ross Island volcanic complex began forming with the emplacement of the basaltic shield volcanoes of Mt. Bird and Mt. Terror between ca. 4.6 and 1.3 Ma, though it has developed most significantly over the last 1 Ma during an eruptive phase resulting in the 3794-m-high composite vent of Mt. Erebus. Throughout this time, loading of the lithosphere at the southern end of the Terror Rift by the Ross Island volcanic pile has progressively depressed the crust, resulting in a subcircular flexural moat around the periphery of the island. Multichannel seismic reflection data collected from the McMurdo-Ross Ice Shelf (MRIS) reveal the stratigraphic architecture of the moat-fill on the southeastern side of Ross Island. The moat region has accommodated a well-stratified, regionally extensive sedimentary succession of at least 1.2 km below the seafloor in the deepest part of the depression. Three seismic stratigraphic units are identified that generally thicken and dip towards Ross Island and are bounded by angular (onlap) unconformities. We infer that the three units were deposited in accommodation space created during discrete phases of volcanic load-induced subsidence: Unit III. Moderate to low-amplitude discontinuous reflectors are dislocated and tilted by normal faulting and interpreted to represent coarse-grained glacigenic and fine-grained marine sediments with likely intercalated volcanic ash. These strata may have started to accumulate during loading of the crust by Mt. Bird between ca. 4.6 and 3.8 Ma. Unit II. Moderate to high-amplitude continuous reflectors that onlap Unit III and are interpreted to represent coarse-grained glacigenic and fine-grained marine sediments with likely intercalated volcanic ash. These strata are inferred to have accumulated in the crustal depression resulting from loading by Mt. Terror between ca. 1.8 and 1.3 Ma. Unit I. Relatively continuous low-amplitude to seismically-opaque reflectors (Unit IB), onlap Unit II and grade upwards into

  10. Miocene Antarctic ice dynamics in the Ross Embayment (Western Ross Sea, Antarctica): Insights from provenance analyses of sedimentary clasts in the AND-2A drill core

    NASA Astrophysics Data System (ADS)

    Cornamusini, Gianluca; Talarico, Franco M.

    2016-11-01

    A detailed study of gravel-size sedimentary clasts in the ANDRILL-2A (AND-2A) drill core reveals distinct changes in provenance and allows reconstructions to be produced of the paleo ice flow in the McMurdo Sound region (Ross Sea) from the Early Miocene to the Holocene. The sedimentary clasts in AND-2A are divided into seven distinct petrofacies. A comparison of these with potential source rocks from the Transantarctic Mountains and the coastal Southern Victoria Land suggests that the majority of the sedimentary clasts were derived from formations within the Devonian-Triassic Beacon Supergroup. The siliciclastic-carbonate petrofacies are similar to the fossiliferous erratics found in the Quaternary Moraine in the southern McMurdo Sound and were probably sourced from Eocene strata that are currently hidden beneath the Ross Ice Shelf. Intraformational clasts were almost certainly reworked from diamictite and mudstone sequences that were originally deposited proximal to the drill site. The distribution of sedimentary gravel clasts in AND-2A suggests that sedimentary sequences in the drill core were deposited under two main glacial scenarios: 1) a highly dynamic ice sheet that did not extend beyond the coastal margin and produced abundant debris-rich icebergs from outlet glaciers in the central Transantarctic Mountains and South Victoria Land; 2) and an ice sheet that extended well beyond the coastal margin and periodically advanced across the Ross Embayment. Glacial scenario 1 dominated the early to mid-Miocene (between ca. 1000 and 225 mbsf in AND-2A) and scenario 2 the early Miocene (between ca. 1138 and 1000 mbsf) and late Neogene to Holocene (above ca. 225 mbsf). This study augments previous research on the clast provenance and highlights the added value that sedimentary clasts offer in terms of reconstructing past glacial conditions from Antarctic drill core records.

  11. CLOUDS IN THE COLDEST BROWN DWARFS: FIRE SPECTROSCOPY OF ROSS 458C

    SciTech Connect

    Burgasser, Adam J.; Simcoe, Robert A.; Bochanski, John J.; Saumon, Didier; Mamajek, Eric E.; McMurtry, Craig; Pipher, Judith L.; Forrest, William J.; Cushing, Michael C.; Marley, Mark S.

    2010-12-20

    Condensate clouds are a salient feature of L dwarf atmospheres, but have been assumed to play little role in shaping the spectra of the coldest T-type brown dwarfs. Here we report evidence of condensate opacity in the near-infrared spectrum of the brown dwarf candidate Ross 458C, obtained with the Folded-Port Infrared Echellette (FIRE) spectrograph at the Magellan Telescopes. These data verify the low-temperature nature of this source, indicating a T8 spectral classification, log{sub 10} L{sub bol}/L{sub sun} = -5.62 {+-} 0.03, T{sub eff} = 650 {+-} 25 K, and a mass at or below the deuterium burning limit. The data also reveal enhanced emission at the K band associated with youth (low surface gravity) and supersolar metallicity, reflecting the properties of the Ross 458 system (age = 150-800 Myr, [Fe/H] = +0.2 to +0.3). We present fits of FIRE data for Ross 458C, the T9 dwarf ULAS J133553.45+113005.2, and the blue T7.5 dwarf SDSS J141624.08+134826.7B, to cloudless and cloudy spectral models from Saumon and Marley. For Ross 458C, we confirm a low surface gravity and supersolar metallicity, while the temperature differs depending on the presence (635{sup +25}{sub -35} K) or absence (760{sup +70}{sub -45} K) of cloud extinction. ULAS J1335+1130 and SDSS J1416+1348B have similar temperatures (595{sup +25}{sub -45} K), but distinct surface gravities (log g = 4.0-4.5 cgs versus 5.0-5.5 cgs) and metallicities ([M/H] {approx} +0.2 versus -0.2). In all three cases, cloudy models provide better fits to the spectral data, significantly so for Ross 458C. These results indicate that clouds are an important opacity source in the spectra of young cold T dwarfs and should be considered when characterizing planetary-mass objects in young clusters and directly imaged exoplanets. The characteristics of Ross 458C suggest that it could itself be regarded as a planet, albeit one whose cosmogony does not conform with current planet formation theories.

  12. Phytoplankton blooms during austral summer in the Ross Sea, Antarctica: Driving factors and trophic implications

    PubMed Central

    Saggiomo, Vincenzo; Bolinesi, Francesco; Margiotta, Francesca; Budillon, Giorgio; Cotroneo, Yuri; Misic, Cristina; Rivaro, Paola; Saggiomo, Maria

    2017-01-01

    During the austral summer of 2014, an oceanographic cruise was conducted in the Ross Sea in the framework of the RoME (Ross Sea Mesoscale Experiment) Project. Forty-three hydrological stations were sampled within three different areas: the northern Ross Sea (RoME 1), Terra Nova Bay (RoME 2), and the southern Ross Sea (RoME 3). The ecological and photophysiological characteristics of the phytoplankton were investigated (i.e., size structure, functional groups, PSII maximum quantum efficiency, photoprotective pigments), as related to hydrographic and chemical features. The aim was to identify the mechanisms that modulate phytoplankton blooms, and consequently, the fate of organic materials produced by the blooms. The observed biomass standing stocks were very high (e.g., integrated chlorophyll-a up to 371 mg m-2 in the top 100 m). Large differences in phytoplankton community composition, relative contribution of functional groups and photosynthetic parameters were observed among the three subsystems. The diatoms (in different physiological status) were the dominant taxa in RoME 1 and RoME 3; in RoME 1, a post-bloom phase was identified, whereas in RoME 3, an active phytoplankton bloom occurred. In RoME 2, diatoms co-occurred with Phaeocystis antarctica, but were vertically segregated by the upper mixed layer, with senescent diatoms dominating in the upper layer, and P. antarctica blooming in the deeper layer. The dominance of the phytoplankton micro-fraction over the whole area and the high Chl-a suggested the prevalence of non-grazed large cells, independent of the distribution of the two functional groups. These data emphasise the occurrence of significant temporal changes in the phytoplankton biomass in the Ross Sea during austral summer. The mechanisms that drive such changes and the fate of the carbon production are probably related to the variations in the limiting factors induced by the concurrent hydrological modifications to the Ross Sea, and they remain to

  13. Temporal and Spatial Variability of Ross polynya using Multi-Satellite Observations

    NASA Astrophysics Data System (ADS)

    Park, J.; Jo, Y. H.

    2014-12-01

    Polynyas are particularly vulnerable to not only local environmental changes, but also global climate changes through air-sea-ice interactions. In order to understand the large scales of its interactions, a temporal and spatial variation of polynyas and, areas of open water in the middle of ice shelf, around the Antarctica were analyzed based on remote sensing measurements. Especially, the polynya in the Ross Sea (Ross polynya) was analyzed, which was the largest on among the all of them around the Antarctica for last decades. Accordingly, the main purpose of this presentation is to (1) evaluate a variability of Ross polynya spatial and temporal characteristics and (2) address relationship between spatial polynya variability and global warming effect. In order to conduct research the observations from the Advanced Microwave Scanning Radiometer-EOS (AMAR-E) were used. The products (SST, wind speed, cloud vapor, atmospheric water vapor and rain rate), including sea ice extent, are from June 2002 to October 2011. Additionally, Gravity Recovery and Climate Experiment (GRACE) data sets were used to estimate mass changes in adjacent ice sheet affected by local atmospheric condition. Based on the nine year's data, research results suggest that Ross polynya normally started to appear around the end of December and persist for about 77.5 days. The extent of Ross polynya in 2011 is the largest and had a tendency to increase year after year. SST in adjacent sea has slightly decreased for the same period (as 0.054◦C yr-1) due to the melting ice and variation of wind, water vapor and rain rate are 0.054 m s-1 yr-1, -0.027 mm yr-1 and 0.001 mm hr-1 yr-1, respectively. Increase land mass in the west-southern Antarctica could be the result of accumulating snow which is made of vapor induced by extended polynya. In addition, we would conduct to evaluate a correlation with characteristics of other global and local components corresponding climate change and understand that how the

  14. Phytoplankton blooms during austral summer in the Ross Sea, Antarctica: Driving factors and trophic implications.

    PubMed

    Mangoni, Olga; Saggiomo, Vincenzo; Bolinesi, Francesco; Margiotta, Francesca; Budillon, Giorgio; Cotroneo, Yuri; Misic, Cristina; Rivaro, Paola; Saggiomo, Maria

    2017-01-01

    During the austral summer of 2014, an oceanographic cruise was conducted in the Ross Sea in the framework of the RoME (Ross Sea Mesoscale Experiment) Project. Forty-three hydrological stations were sampled within three different areas: the northern Ross Sea (RoME 1), Terra Nova Bay (RoME 2), and the southern Ross Sea (RoME 3). The ecological and photophysiological characteristics of the phytoplankton were investigated (i.e., size structure, functional groups, PSII maximum quantum efficiency, photoprotective pigments), as related to hydrographic and chemical features. The aim was to identify the mechanisms that modulate phytoplankton blooms, and consequently, the fate of organic materials produced by the blooms. The observed biomass standing stocks were very high (e.g., integrated chlorophyll-a up to 371 mg m-2 in the top 100 m). Large differences in phytoplankton community composition, relative contribution of functional groups and photosynthetic parameters were observed among the three subsystems. The diatoms (in different physiological status) were the dominant taxa in RoME 1 and RoME 3; in RoME 1, a post-bloom phase was identified, whereas in RoME 3, an active phytoplankton bloom occurred. In RoME 2, diatoms co-occurred with Phaeocystis antarctica, but were vertically segregated by the upper mixed layer, with senescent diatoms dominating in the upper layer, and P. antarctica blooming in the deeper layer. The dominance of the phytoplankton micro-fraction over the whole area and the high Chl-a suggested the prevalence of non-grazed large cells, independent of the distribution of the two functional groups. These data emphasise the occurrence of significant temporal changes in the phytoplankton biomass in the Ross Sea during austral summer. The mechanisms that drive such changes and the fate of the carbon production are probably related to the variations in the limiting factors induced by the concurrent hydrological modifications to the Ross Sea, and they remain to

  15. Effects of male removal on female reproductive biology in Ross' and Lesser Snow Geese

    USGS Publications Warehouse

    Leschack, C.R.; Afton, A.D.; Alisauskas, R.T.

    1998-01-01

    We studied effects of mate removal on nesting and hatching success, incubation behavior, body mass, and post-hatch dispersal distance of female Ross' (Chen rossii) and Lesser Snow Geese (C. caerulescens caerulescens) at Karrak Lake. N.W.T., Canada. Male ge and widowed and paired control females were monitored through post-hatch dispersal. Nesting and hatching success did not differ between species or treatments (widowed vs paired) and averaged 77.5 ?? 3.8% and 64.0 ?? 3.6% (??SE), respectively. Paired females spent more time with their bills tucked (23.7 ?? 3.3% vs 9.1 ?? 4.0%) and less time alert (8.6 ?? 2.9% vs 22.9 ?? 3.5%) while on nests than did widowed females. Snow widowed females (31.1 ?? 4.7%) and Ross' widowed females (20.6 ?? 6.0%) generally spent more time each day in head-up alert than did Snow paired females (7.1 ?? 3.8%). Snow paired maleS (11.8 ?? 3.8%), Ross' paired females (9.4 ?? 3.6%), and Ross' paired males (7.9 ?? 3.6%). Body mass of paired and widowed female Ross' Geese did not differ at hatch or at time of post-hatch recapture; however, mean distance recaptured from the breeding colony was greater for paired (50.9 ?? 6.1 km) than for widowed females (27.3 ?? 6.6 km). Total mass gain (276 ?? 19 g) and rate of mass gain (8.4 ?? 0.5 g/day), from hatch until post-hatch recapture (33.1 ?? 1.2 days), were similar for widowed and paired female Ross' Geese. Male removal experiments in monogamous, precocial species generally have produced few effects on female nesting success or incubation behavior. We suggest that male parental care in arctic-nesting geese is more critical during laying and the post-hatch period than during incubation.

  16. Retreat history of the last glacial maximum ice sheet in Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Shipp, Stephanie Staples

    High-resolution geophysical and geologic data were acquired in western and central Ross Sea, Antarctica, to determine the: (1) maximum extent and configuration of the ice sheet during the Last Glacial Maximum (LGM); (2) conditions and processes at the base of the expanded ice sheet and their role in ice stream activity; and (3) relative retreat history of the ice sheet. This information can provide geologic constraints for modeling of ice-sheet retreat. The research formed the basis for development of a public Web site (http://www.glacier.rice.edu) and for middle-school earth-science instructional materials. Based on identification of isolated grounding-zone wedges and consistency of mega-scale glacial lineations, the LGM ice edge reached the Coulman Island region in western Ross Sea. The maximum extent in central Ross Sea occurred at the continental-shelf edge, based on the presence of mega-scale glacial lineations, glacio-tectonic features, and shelf-edge gullies. Streaming ice, overlying a deforming bed typically <5 m in thickness, filled the troughs. Thinner, divergent, slower moving ice, not underlain by deforming sediment, occupied the bank tops. The ice sheet eroded and conveyed sediment from the inner regions toward the outer shelf, where the material was deposited at the grounding line. No features associated with meltwater occur; water available to the subglacial system probably was incorporated into a deforming unit. The ice sheet may have undergone an initial phase of mass wasting, based the large, arcuate iceberg furrows associated with the grounding zones. Ice retreated first from western Ross Sea, possibly because of a diminished contribution from the East Antarctic Ice Sheet. Ice retreat from central Ross Sea lagged that of western Ross Sea. The banks remained ice covered after ice retreat from the troughs; ice shelves may have covered the troughs. During retreat, the grounded ice reworked the substrate into back-stepping grounding-zone wedges and

  17. STS-88 Mission Specialist Jerry Ross arrives at KSC for TCDT

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-88 Mission Specialist Jerry L. Ross arrives after dark at the Shuttle Landing Facility to take part in Terminal Countdown Demonstration Test (TCDT) activities. The TCDT provides the crew with simulated countdown exercises, emergency egress training, and opportunities to inspect their mission payloads in the orbiter's payload bay. Mission STS-88 is targeted for launch on Dec. 3, 1998. It is the first U.S. flight for the assembly of the International Space Station and will carry the Unity connecting module. Others in the STS-88 crew are Commander Robert D. Cabana, Pilot Frederick W. 'Rick' Sturckow, Mission Specialists Nancy J. Currie and James H. Newman and Russian cosmonaut Sergei Konstantinovich Krikalev. Ross and Newman will make three spacewalks to connect power, data and utility lines and install exterior equipment.

  18. Percutaneous valved stent repair of a failed homograft: implications for the Ross procedure.

    PubMed

    Pretorius, Victor; Jones, Alan; Taylor, Dylan; Coe, Yashu; Ross, David B

    2008-08-01

    A case of percutaneous pulmonary valve implantation following a failed homograft in the pulmonary position is reported. A 16-year-old boy developed infective endocarditis of his pulmonary homograft, which was implanted four years earlier during a Ross procedure for congenital aortic stenosis. Following successful medical therapy, the boy was symptomatic due to pulmonary stenosis and regurgitation. A 22 mm Melody valve (Medtronic, USA) was successfully implanted percutaneously. His symptoms resolved and he was discharged home one day after the procedure. Echocardiography at the six-month follow-up demonstrated a normally functioning pulmonary valve. Percutaneous pulmonary valve replacement may make the Ross procedure a more attractive option for patients with aortic stenosis, particularly in the pediatric population.

  19. STS-74 Mission Specialists McArther and Ross in OPF

    NASA Technical Reports Server (NTRS)

    1995-01-01

    In Orbiter Processing Facility Bay 2, STS-74 Mission Specialist William 'Bill' McArthur Jr. (left) and Jerry L. Ross are reviewing the configuration of payload elements in the orbiter Atlantis' payload bay. Ross and McArthur are participating in the Crew Equipment Interface Test (CEIT), an opportunity for flight crew members to become familiar with the payload hardware they will be working with on-orbit. Located in Atlantis' payload bay are the Orbiter Docking System and the Docking Module, two pieces of flight hardware that will play a crucial role in the second docking of the Space Shuttle to the Russian Space Station Mir. STS-74 is currently targeted for an early November launch

  20. Isolated generalised anhidrosis induced by postganglionic sympathetic skin nerve fibre degeneration: an incomplete Ross syndrome?

    PubMed

    Donadio, V; Cortelli, P; Falzone, F; Bugiardini, E; Giuliani, A; Misciali, C; Montagna, P; Calzà, L; Liguori, R

    2008-08-01

    Ross syndrome is characterised by tonic pupil, areflexia and anhidrosis, and the underlying lesion affects postganglionic skin sympathetic nerve fibres. We describe a 51-year-old man who had complained of anhidrosis since adolescence, at which time this problem was limited to the lower arms. The thermoregulatory sweating test disclosed generalised anhidrosis (GA) except for two small skin areas that were located in the right palm and left neck. Immunofluorescence analysis disclosed no cholinergic sudomotor fibres around the sweat glands of non-sweating skin areas, which were evident although sparse and deranged in the sweating site. In our patient, GA was induced by degeneration of postganglionic sympathetic skin nerve fibres, as found in Ross syndrome, although his clinical picture was incomplete as it lacked tonic pupil and areflexia. Isolated GA induced by degeneration of postganglionic sympathetic nerve fibers, directly evaluated by skin biopsy, has not previously been described.

  1. A Battle of Words: "Dignity" and "Peace" in the Writings of Elisabeth Kübler-Ross.

    PubMed

    Burnier, Daniel

    2017-01-01

    This article analyzes the writings of Elisabeth Kübler-Ross through the discursive lens of the phrase "dying with dignity." For her, the phrase meant allowing someone to die comfortably his/her own death. This phrase has to be understood in relationship with the final "stage of acceptance" of her model. Describing this key part of her well-known scientific output, she often used, in the early 1970s, the phrase "dying in peace and dignity." An evaluation of the evidence suggests that because the concept of dignity was co-opted by the pro-euthanasia movement during this decade, the language of dignity was little by little abandoned by her. In later years, only "peace" survived from her favorite expression. Although this concept of peace remains present to the end in all Kübler-Ross writings, the pro-euthanasia movement has also started to speak the language of peace.

  2. Northern Victoria Land (western Ross Sea-Antarctica): inner shelf fine sedimentation

    NASA Astrophysics Data System (ADS)

    Colizza, E.; Finocchiaro, F.; Ivaldi, R.; Pittà, A.; Tolotti, R.; Brambati, A.

    2003-04-01

    The Holocene sedimentation conditions are represented, in the western Ross Sea, by diatomaceous ooze in the uppermost part of sedimentary sequences, while diamicton deposited during Last Glacial Maximum are the basal unit of most cores. Thick layer (> 2 m) of diatomaceous ooze were sampled in the northern Joides Basin and into Granite Harbour. In Drygalski Ice Tongue area and along the coasts of northern Victoria Land, prevails coarse sedimentation, due to seaward flowing of large outlet glacier that drain the Transantarctic Mountain. During 1998-99 and 2001-02 PNRA antarctic cruises, favourable sea ice conditions, has allowed to sample inner shelf area, both in Wood Bay and south of Drygalski ice tongue (Nordenskjold basin). In both sites fine laminated diatomaceous mud are present. Preliminary seismostratigraphy and sedimentological data are here reported. This is the first note of new sites of fine sedimentation in the Ross Sea inner shelf.

  3. Dr Ross McIntire, otolaryngologist, and his care of President Franklin D. Roosevelt.

    PubMed

    Ruben, Robert J

    2009-07-01

    The role that otolaryngologist Ross McIntire, MD, played in the care of Franklin Delano Roosevelt, 32nd President of the United States, was documented by reviewing primary source material pertaining to the relationship of McIntire and Roosevelt. This included material from various archives including the Franklin D. Roosevelt Presidential Library at Hyde Park, New York; United States National Archives; and numerous autobiographies and diaries. McIntire's belief in the value of confidentiality and to provide information only on a need-to-know basis is consistent with the strategy that he had devised earlier for protecting his patient's privacy. In the context of his time and his position, Dr McIntire served his patient and his country well by making appropriate medical and wise personal judgments. The career of Dr Ross T. McIntire, otolaryngologist and personal physician to the 32nd president of the United States, engenders a sense of honor to our profession.

  4. James Ross (1837-1892) and his forgotten neurology textbook of 1881.

    PubMed

    Eadie, M J

    2010-09-01

    James Ross (1837-1892) was an Aberdeen medical graduate who, after 13 years in rural general practice, mainly in Lancashire, became a pathologist and then physician to the Manchester Royal Infirmary and professor of medicine at Owens College, Manchester. In mid-career he developed a major interest in clinical neurology and became, apart from Byrom Bramwell in Edinburgh, the only contemporary British physician outside London who had widely recognised neurological expertise. Ross made several notable original contributions to neurological knowledge, particularly in relation to aphasia and peripheral neuritis. He wrote the entire contents of the two editions of the massive two-volume A Treatise on the Diseases of the Nervous System (1881 and 1883), which was very favourably reviewed and commercially successful but which, like its author who died at the height of his powers, was soon forgotten once William Gowers' A Manual of Diseases of the Nervous System became available in the late 1880s.

  5. A new age constraint on the deglaciation of the Ross Sea from an ice core from Roosevelt Island, East Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Lee, J. E.; Brook, E.; Blunier, T.; Bertler, N. A. N.; Vallelonga, P. T.

    2014-12-01

    A new ice core from Roosevelt Island was drilled for the Roosevelt Island Climate Evolution (RICE) project to establish the history of deglaciation of the Ross Sea through the Holocene. Evidence of glacial retreat in the Ross Sea Embayment shows that deglaciation happened in several stages of rapid collapse and persisted well after the melting of the Northern Hemisphere ice sheets was complete. The ice rise on Roosevelt Island should record the timing of the recession of the West Antarctic Ice Sheet (WAIS) past Roosevelt Island. The transition between ice originating from WAIS and ice originating local to Roosevelt Island could, in principle, be identified in the RICE ice core by the Total Air Content (TAC), which depends on surface air pressure and climate. Because the accumulation zone of WAIS is at a higher altitude than Roosevelt Island, it is expected that TAC will record a sharp drop during the transition. Existing data back to 3.7 ka show a relatively constant air content, probably implying only small elevation changes over that time. New results from deeper sections will be discussed at the meeting.

  6. Lesser snow geese and ross's geese form mixed flocks during winter but differ in family maintenance and social status

    USGS Publications Warehouse

    Jonsson, J.E.; Afton, A.D.

    2008-01-01

    Smaller species are less likely to maintain families (or other forms of social groups) than larger species and are more likely to be displaced in competition with larger species. We observed mixed-species flocks of geese in southwest Louisiana and compared frequencies of social groups and success in social encounters of Lesser Snow Geese (Chen caerulescens caerulescens; hereafter Snow Geese) with that of the smaller, closely- related Ross's Geese (C. rossii). Less than 7% of adult and Ross's Geese were in families, whereas 10-22% of adult and 12-15% of juvenile Snow Geese were in families. Snow Geese won 70% of interspecific social encounters and had higher odds of success against Ross's Geese than against individuals of their own species. The larger Snow Geese maintain families longer than Ross's Geese, which probably contributes to their dominance over Ross's Geese during winter. Predator vigilance probably is an important benefit of mixed flocking for both species. We suggest the long-standing association with Snow Geese (along with associated subordinate social status) has selected against family maintenance in Ross's Geese.

  7. Monitoring Subsurface Ice-Ocean Processes Using Underwater Acoustics in the Ross Sea

    NASA Astrophysics Data System (ADS)

    Haxel, J. H.; Dziak, R. P.; Matsumoto, H.; Lee, W. S.; Yun, S.

    2016-12-01

    The Ross Sea is a dynamic area of ice-ocean interaction, where a large component of the Southern Ocean's sea ice formation occurs within regional polynyas in addition to the destructive processes happening at the seaward boundary of the Ross Ice Shelf. Recent studies show the sea-ice season has been lengthening and the sea ice extent has been growing with more persistent and larger regional polynyas. These trends have important implications for the Ross Sea ecosystem with polynyas supporting high rates of primary productivity in the area. Monitoring trends in sea ice and ice shelf dynamics in the Southern Ocean has relied heavily on satellite imagery and remote sensing methods despite a significant portion of these physical processes occurring beneath the ocean surface. In January 2014, an ocean bottom hydrophone (OBH) was moored on the seafloor in the polynya area of Terra Nova Bay in the northwest region of the Ross Sea, north of the Drygalski Ice Tongue. The OBH recorded a year long record of the underwater low frequency acoustic spectrum up to 500 Hz from January 29 until it was recovered the following December 17, 2014. The acoustic records reveal a complex annual history of ice generated signals with over 50,000 detected events. These ice generated events related to collisions and cracking provide important insight for the timing and intensity of the ice-ocean dynamics happening below the sea surface as the polynya grows and expands and the nearby Drygalski ice tongue flows into Terra Nova Bay. Additionally, high concentrations of baleen whale vocalizations in frequencies ranging from 200-400 Hz from September - December suggest a strong seasonal presence of whales in this ecologically important polynya region.

  8. MR imaging of right ventricular function after the Ross procedure for aortic valve replacement: initial experience.

    PubMed

    Grotenhuis, Heynric B; de Roos, Albert; Ottenkamp, Jaap; Schoof, Paul H; Vliegen, Hubert W; Kroft, Lucia J M

    2008-02-01

    To prospectively assess right ventricular (RV) function after the Ross procedure by using magnetic resonance (MR) imaging. The local ethics committee approved the study and informed consent was obtained from all participants prior to enrollment in the study. Seventeen patients (15 male, two female; mean age +/- standard deviation, 19 years +/- 3.9; imaging performed 8.3 years after surgery +/- 3.2) and 17 matched controls (15 male, two female; mean age +/- standard deviation, 20 years +/- 3.9) were studied by using MR imaging. Standard velocity-encoded and multisection multiphase imaging sequences were used to assess homograft valve function, systolic and diastolic RV function, and RV mass. The two-tailed Mann-Whitney U test and the Spearman rank correlation coefficient were used for statistical analysis. Minor degrees of homograft stenosis (peak flow velocity between 1.5 and 3.0 m/sec across the homograft valve) were found in 12 of 17 patients but not in controls (P < .001). A larger RV mass was present in Ross patients than in controls (17.0 g/m(2) +/- 4.8 vs 10.9 g/m(2) +/- 5.6, P = .004). In addition, impaired diastolic RV function was found, as shown by a decreased mean tricuspid valve early filling phase-atrial contraction phase (E/A) peak flow velocity ratio (1.56 +/- 0.75 vs 2.05 +/- 0.58, P = .03). Peak flow velocity across the homograft valve correlated with RV mass (r = 0.38, P = .03) and tricuspid valve E/A peak flow velocity ratio (r = 0.39, P = .02). RV systolic function was normal in Ross patients (mean RV ejection fraction, 52% +/- 8 vs 51% +/- 5; P = .74). RV hypertrophy and RV diastolic dysfunction are frequently observed in patients after the Ross procedure, even in the absence of overt homograft stenosis. RV systolic function is still preserved. (c) RSNA, 2007.

  9. Enumeration of Thermophilic Heterotrophs in Geothermally Heated Soils from Mount Erebus, Ross Island, Antarctica

    PubMed Central

    Hudson, J. Andrew; Daniel, Roy M.

    1988-01-01

    Soil samples with temperatures up to 64°C were collected from Mount Erebus, an active volcano located on Ross Island, Antarctica. Acridine orange direct counts and most probable number counts of soil samples stored at 4°C for 2 months showed a wide variation in the number of thermophilic microorganisms in different soils. Organisms similar to Clostridium thermohydrosulfuricum, Bacillus schlegelii, and Bacillus acidocaldarius, as well as neutrophilic Bacillus strains, were isolated. PMID:16347573

  10. Enumeration of thermophilic heterotrophs in geothermally heated soils from mount erebus, ross island, antarctica.

    PubMed

    Hudson, J A; Daniel, R M

    1988-02-01

    Soil samples with temperatures up to 64 degrees C were collected from Mount Erebus, an active volcano located on Ross Island, Antarctica. Acridine orange direct counts and most probable number counts of soil samples stored at 4 degrees C for 2 months showed a wide variation in the number of thermophilic microorganisms in different soils. Organisms similar to Clostridium thermohydrosulfuricum, Bacillus schlegelii, and Bacillus acidocaldarius, as well as neutrophilic Bacillus strains, were isolated.

  11. Clouds On A Cold Planet: FIRE Spectroscopy Of Ross 458C

    NASA Astrophysics Data System (ADS)

    Burgasser, Adam J.; Simcoe, R. A.; Bochanski, J. J.; Saumon, D.; Mamajek, E. E.; Cushing, M. C.; Marley, M. S.; McMurtry, C.; Pipher, J. L.; Forrest, W. J.

    2011-01-01

    Ross 458C is a widely-separated (1100 AU), faint companion to the nearby M0.5 Ve + M7 Ross 458AB binary, identified in the UKIDSS survey by Goldman et al. and Scholz and suspected by both of being a young brown dwarf. We obtained near-infrared spectroscopy of this source with the newly-commissioned Folded-Port Infrared Echellette (FIRE) at the Magellan Telescopes, which revealed the presence of strong methane and water absorption consistent with a T8 dwarf. The age of this system (150-800 Myr) and the low luminosity of the companion (log Lbol/Lsun = -5.62±0.03) indicate a mass at or below the deuterium burning limit. This is verified through atmospheric model fits to the spectral data, which indicate a low temperature (635 [+25,-35] K), a low surface gravity (log g 4 cgs) and a model-dependent mass of <=6 Jupiter masses. The spectral models further indicate that condensate clouds are present in the atmosphere of Ross 458C, in contrast to results for other cold T dwarfs. These results provide further evidence that clouds are an important opacity source in the spectra of young substellar objects, from planetary-mass brown dwarfs in young clusters to directly-imaged exoplanets. Moreover, its low mass, cool atmosphere and physical association with a stellar system give Ross 458C all of the trappings of a planet, albeit one whose cosmogony may not conform with current planet formation theories. This result includes data gathered with the 6.5-m Magellan Telescopes located at Las Campanas Observatory, Chile. Support for the modeling work of D.S. was provided by NASA through the Spitzer Science Center.

  12. Effects of physical constraints on the lability of POM during summer in the Ross Sea

    NASA Astrophysics Data System (ADS)

    Misic, Cristina; Covazzi Harriague, Anabella; Mangoni, Olga; Aulicino, Giuseppe; Castagno, Pasquale; Cotroneo, Yuri

    2017-02-01

    The 0-200 m surface layer of the Ross Sea was studied during summer 2014 to investigate the lability of the particulate organic matter (POM) in response to physical parameters. With the use of satellite information, we selected three zones, characterised by different physical setting: a northern offshore area, crossing the summer-polynya area of the Ross Sea (hereafter called ROME 1), a more coastal area next to the Terra Nova Bay polynya (ROME 2); a southern offshore area, towards the Ross Ice Shelf (ROME 3). Ice-maps showed that the seasonal ice retreat had already occurred in early December for most of the stations. Statistical analysis of the quantitative and qualitative characteristics of the POM pointed to significant differences between the stations, especially in the upper mixed layer (UML). A comparison with previous studies showed that the localised pulses of POM accumulation in the UML were similar to those recorded at the highly productive marginal ice zones, providing notable trophic support to the ecosystem. The UML, although rather thin and easily subjected to alterations, confirmed its pivotal role in the ecosystem dynamics. A POM quality favourable to consumers was highlighted at several stations in ROME 1 and ROME 3. Reduced trophic support was, instead, found in ROME 2. Limited POM consumption where deep-water formation takes place would increase the POM role in the transfer of C to the depths.

  13. Collaborative Research and Education in the Ross Sea: A broader impact evaluation report

    NASA Astrophysics Data System (ADS)

    Parsons, C.; Kohut, J. T.; Lichtenwalner, C. S.; Clark, H.

    2010-12-01

    An interdisciplinary team of researchers will focus on describing the high productivity patchiness observed in phytoplankton blooms in the mid-to-late summer in the Ross Sea, Antarctica. They will use a novel sampling strategy that employs a remotely controlled glider (AUV) to locate and map circumpolar deep water in near real time and also to direct further ship-based sampling. This unusual coordination of a polar research vessel with AUVs provides an exciting opportunity to engage formal and informal educators in a research adventure. As part of this NSF-funded project’s Criterion 2 broader impact, joining the researchers virtually will be 30 New Jersey middle-school teachers and their students. This summer in New Jersey, in partnership with Liberty Science Center educators, COSEE-NOW (Centers for Ocean Sciences Education Excellence-Networked Ocean World) and Woods Hole Oceanographic Institution, the project team introduced teachers to the Ross Sea, the research, the science behind it and the AUV. The summer workshop and ongoing schoolyear support is providing the teachers with the tools they need to bring the excitement of the research into their classrooms in real time during the Ross Sea cruise at the end of this year. This presentation by Chris Parsons, the project evaluator, will summarize the evaluation plan for this broader impact project, which follows teachers and their classes for a year, and provide the latest evaluation results from this project.

  14. Forced copulation results in few extrapair fertilizations in Ross's and lesser snow geese

    USGS Publications Warehouse

    Dunn, P.O.; Afton, A.D.; Gloutney, M.L.; Alisauskas, R.T.

    1999-01-01

    Extrapair paternity varies from 0 to over 70% of young among various populations of birds. Comparative studies have suggested that this variation is related to nesting density, breeding synchrony and the proportion of extrapair copulations. We used minisatellite DNA fingerprinting to examine levels of extrapair paternity in Ross's geese, Chen rossi, and lesser snow geese, C. caerulescens c. (hereafter snow geese) nesting in the largest known goose colony in the world. These geese have one of the highest known percentages of extrapair copulation (46-56% of all attempted copulations), and all of these appeared to be forced. Among all successful copulations, 33 and 38% were extrapair in Ross's and snow geese, respectively. Despite the high percentage of extrapair copulations, extrapair paternity was low in both Ross's and snow geese (2-5% of young). Extrapair paternity was not related to nest density in either species. However, in snow geese, extrapair paternity was more likely to occur in nests of females that nested asynchronously, either early or late in the season. This is one of a few reported examples of a negative relationship between extrapair paternity and breeding synchrony. Extrapair young also tended to come from eggs laid later in the clutch. Although forced extrapair copulations appear to be a relatively inefficient reproductive tactic for males, they may provide a reproductive advantage for some males.

  15. Tidal Modulation of Ice-shelf Flow: a Viscous Model of the Ross Ice Shelf

    NASA Technical Reports Server (NTRS)

    Brunt, Kelly M.; MacAyeal, Douglas R.

    2014-01-01

    Three stations near the calving front of the Ross Ice Shelf, Antarctica, recorded GPS data through a full spring-neap tidal cycle in November 2005. The data revealed a diurnal horizontal motion that varied both along and transverse to the long-term average velocity direction, similar to tidal signals observed in other ice shelves and ice streams. Based on its periodicity, it was hypothesized that the signal represents a flow response of the Ross Ice Shelf to the diurnal tides of the Ross Sea. To assess the influence of the tide on the ice-shelf motion, two hypotheses were developed. The first addressed the direct response of the ice shelf to tidal forcing, such as forces due to sea-surface slopes or forces due to sub-ice-shelf currents. The second involved the indirect response of ice-shelf flow to the tidal signals observed in the ice streams that source the ice shelf. A finite-element model, based on viscous creep flow, was developed to test these hypotheses, but succeeded only in falsifying both hypotheses, i.e. showing that direct tidal effects produce too small a response, and indirect tidal effects produce a response that is not smooth in time. This nullification suggests that a combination of viscous and elastic deformation is required to explain the observations.

  16. Model sensitivity of the Weddell and Ross seas, Antarctica, to vertical mixing and freshwater forcing

    NASA Astrophysics Data System (ADS)

    Kjellsson, Joakim; Holland, Paul R.; Marshall, Gareth J.; Mathiot, Pierre; Aksenov, Yevgeny; Coward, Andrew C.; Bacon, Sheldon; Megann, Alex P.; Ridley, Jeff

    2015-10-01

    We examine the sensitivity of the Weddell and Ross seas to vertical mixing and surface freshwater forcing using an ocean-sea ice model. The high latitude Southern Ocean is very weakly stratified, with a winter salinity difference across the pycnocline of only ∼0.2 PSU. We find that insufficient vertical mixing, freshwater supply from the Antarctic Ice Sheet, or initial sea ice causes a high salinity bias in the mixed layer which erodes the stratification and causes excessive deep convection. This leads to vertical homogenisation of the Weddell and Ross seas, opening of polynyas in the sea ice and unrealistic spin-up of the subpolar gyres and Antarctic Circumpolar Current. The model freshwater budget shows that a ∼30% error in any component can destratify the ocean in about a decade. We find that freshwater forcing in the model should be sufficient along the Antarctic coastline to balance a salinity bias caused by dense coastal water that is unable to sink to the deep ocean. We also show that a low initial sea ice area introduces a salinity bias in the marginal ice zone. We demonstrate that vertical mixing, freshwater forcing and initial sea ice conditions need to be constrained simultaneously to reproduce the Southern Ocean hydrography, circulation and sea ice in a model. As an example, insufficient vertical mixing will cause excessive convection in the Weddell and Ross seas even in the presence of large surface freshwater forcing and initial sea ice cover.

  17. Frank Ross's Early Orbits of the First Irregular Satellites of Saturn and Jupiter

    NASA Astrophysics Data System (ADS)

    Osterbrock, Donald E.

    2006-12-01

    Frank E. Ross, later the inventor of the wide-angle lens, photographic photometer, and correcting lens for large reflecting telescopes, developed for the 200-inch, that bear his name, was also an expert on celestial mechanics. After earning his PhD at Berkeley in 1901, he worked in Washington as chief assistant to Simon Newcomb, the leading astronomer of his time, until the latter's death in 1909. W. H. Pickering, who had discovered Phoebe, the first distant, irregular satellite of Saturn, was unable to calculate an orbit for it. He asked Newcomb to do it, but the "grim dean of American astronomy" was too busy, and turned the task over to Ross to do, mostly on his own time. The young assistant succeeded, but spent many sleepless nights on the job. He and his brother Walter were also running a cigar store in Washington at the time. Charles D. Perrine at Lick Observatory discovered J VI and J VII, the first two similar satellites of Jupiter, in 1904 and 1905, and could not obtain satisfactory orbits for them either, even with Director W. W. Campbell's help. Ross then calculated their orbits also, again at a tremendous cost of effort. He used log tables, pencil and paper, and a simple adding machine for his computing tasks, as all "computers" (persons) did at that time. These three satellites were the first to be discovered by photography.

  18. Competing connections between the Ross Ice Shelf with the Southern Ocean.

    NASA Astrophysics Data System (ADS)

    Jendersie, Stefan

    2016-04-01

    The stability of the Ross Ice Shelf (RIS) is critical to both the East Antarctic Ice Sheet, and the West Antarctic Ice Sheet. Results from a climatological ice shelf-ocean coupled numerical model (ROMS) suggest a new circulation mechanism associated with High Salinity Water (HSSW) production in the Ross Sea Polynya (RSP) that controls oceanic heat access to the RIS cavity. Within the RSP the dense water-saturated water column contracts during winter and causes a seasonal drop in Sea Surface Height (SSH) localised to a convection chimney under the RSP. The SSH gradients of up to 1.5 mm per km are sufficient to generate a barotropic pressure gradient that can counteract the wide scale horizontal baroclinic force and reverse the geostrophic circulation. In water depths between 600 and 800 m north of the western RIS the effect causes the seasonal occurrence of a cyclonic circulation cell with transports greater than 1Sv. Appearing with the beginning of winter sea ice formation in the RSP it significantly changes the dynamics at the ice shelf front. The new mechanism is described as one element in a framework of oceanographic processes that mitigate the exchange between the deep ocean and the ocean cavity under the RIS. Our study links local circulation features that are known from observation and previous model studies, and for the first time establishes a coherent system of responsible physical forcing processes in the Ross Sea.​

  19. Forced copulation results in few extrapair fertilizations in Ross's and lesser snow geese.

    PubMed

    Dunn; Afton; Gloutney; Alisauskas

    1999-05-01

    Extrapair paternity varies from 0 to over 70% of young among various populations of birds. Comparative studies have suggested that this variation is related to nesting density, breeding synchrony and the proportion of extrapair copulations. We used minisatellite DNA fingerprinting to examine levels of extrapair paternity in Ross's geese, Chen rossi, and lesser snow geese, C. caerulescens c. (hereafter snow geese) nesting in the largest known goose colony in the world. These geese have one of the highest known percentages of extrapair copulation (46-56% of all attempted copulations), and all of these appeared to be forced. Among all successful copulations, 33 and 38% were extrapair in Ross's and snow geese, respectively. Despite the high percentage of extrapair copulations, extrapair paternity was low in both Ross's and snow geese (2-5% of young). Extrapair paternity was not related to nest density in either species. However, in snow geese, extrapair paternity was more likely to occur in nests of females that nested asynchronously, either early or late in the season. This is one of a few reported examples of a negative relationship between extrapair paternity and breeding synchrony. Extrapair young also tended to come from eggs laid later in the clutch. Although forced extrapair copulations appear to be a relatively inefficient reproductive tactic for males, they may provide a reproductive advantage for some males. Copyright 1999 The Association for the Study of Animal Behaviour.

  20. Control of phytoplankton bloom inception in the Ross Sea, Antarctica, by Ekman restratification

    NASA Astrophysics Data System (ADS)

    Long, Matthew C.; Thomas, Leif N.; Dunbar, Robert B.

    2012-03-01

    Observations from November 2006 in the southwestern Ross Sea indicate that stratification developed in a localized fashion, proximal to upper ocean fronts. These regions were hotspots for biological productivity, exhibiting greater drawdown of CO2and accumulation of oxygen, indicative of enhanced photosynthesis and air-sea gas exchange. While the effect of stratification is clear, the reasons for its development was not; air temperatures were unseasonably cold, sea-ice melt and sea surface warming were not significant. By comparing a one-dimensional mixed layer model with two-dimensional numerical simulations that include horizontal density gradients characteristic of the region, it is shown that Ekman advection is critical to structuring early season stratification. Where fronts are forced by winds that oppose the surface frontal current, Ekman advection displaces lighter water over dense. As biological productivity is light limited in the Ross Sea, and thus sensitive to the depth of the mixed layer, Ekman restratification plays an important role in determining the spatial distribution and development of the annual phytoplankton bloom in the region. The presence of fronts is therefore of first-order importance to the restratification and bloom dynamics of the Ross Sea in the early spring.

  1. Dynamics of surface melting over Amery and Ross ice shelf in Antarctic using OSCAT data

    NASA Astrophysics Data System (ADS)

    Bothale, R. V.; Rao, P. V. N.; Dutt, C. B. S.; Dadhwal, V. K.

    2014-11-01

    Antarctic sea ice sheets play an important role in modulating the climate system. The present study investigates the dynamics of melt/freeze over Amery and Ross ice shelf located in Eastern and Southern part of continent using OSCAT, the microwave scatterometer data from OCEANSAT2. The study utilizes the sensitivity of backscatter coefficient values of scatterometer data to presence of liquid water in the snow caused due to melt conditions. The analysis carried out for four austral winters from 2010-2013 and five austral summer from 2009-2014 showed spatial and temporal variations in average backscatter coefficient over Amery and Ross shelf areas. A dynamic threshold based on the austral winter mean and standard deviation of HH polarization is considered for pixel by pixel analysis for the shelf area. There is significant spatio-temporal variability in melt extent, duration and melt index as observed in the analysis. Spatially, the melt over Amery shelf moves from South to North along coast and West towards inner shelf area. Maximum mean melt occurs on 9th January with January 1-15 fortnight accounting for 80 % of the melt. Extreme low melt conditions were observed during summer 2010-11 and 2011-12 indicating cold summer. Summer 2012-13 and 2013-14 were warm summer. Year 2014 experienced melt only in the month of January with entire shelf under melt conditions. Practically no melt was observed over Ross ice shelf.

  2. Vertical ocean heat redistribution sustaining sea-ice concentration trends in the Ross Sea.

    PubMed

    Lecomte, Olivier; Goosse, Hugues; Fichefet, Thierry; de Lavergne, Casimir; Barthélemy, Antoine; Zunz, Violette

    2017-08-15

    Several processes have been hypothesized to explain the slight overall expansion of Antarctic sea ice over the satellite observation era, including externally forced changes in local winds or in the Southern Ocean's hydrological cycle, as well as internal climate variability. Here, we show the critical influence of an ocean-sea-ice feedback. Once initiated by an external perturbation, it may be sufficient to sustain the observed sea-ice expansion in the Ross Sea, the region with the largest and most significant expansion. We quantify the heat trapped at the base of the ocean mixed layer and demonstrate that it is of the same order of magnitude as the latent heat storage due to the long-term changes in sea-ice volume. The evidence thus suggests that the recent ice coverage increase in the Ross Sea could have been achieved through a reorganization of energy within the near-surface ice-ocean system.The mechanisms responsible for the overall expansion of Antarctic sea-ice in recent decades remain unclear. Here, using observations and model results, the authors show that ice-ocean feedbacks, triggered by an external perturbation, could be responsible for changes in sea-ice extent observed in the Ross Sea.

  3. Subglacial Lake Whillans, West Antarctica; Solute Dynamics and Fluxes to the Ross Sea

    NASA Astrophysics Data System (ADS)

    Skidmore, M. L.; Michaud, A. B.; Achberger, A.; Barbante, C.; Christner, B. C.; Mikucki, J.; Mitchell, A. C.; Priscu, J. C.; Purcell, A. M.; van Gelder, W.; Vick-Majors, T.

    2014-12-01

    Subglacial Lake Whillans is located beneath the Whillans Ice Stream in West Antarctica. The lake is situated beneath 800 m of ice and ~ 70 km upstream of the grounding line where Whillans Ice Stream terminates into the Ross Sea. Subglacial Lake Whillans is a shallow lake and a component of a complex subglacial hydrological system that may resemble a large wetland along the Siple Coast of West Antarctica. Subglacial Lake Whillans drains and refills on a sub-decadal time scale discharging water towards the Ross Sea. Water and sediment samples were recovered from the lake, using clean access drilling technologies, in January, 2013. Isotopic analysis of the lake waters indicates basal meltwater from the ice sheet as the dominant water source. Geochemical analysis of the lake water reveals it is freshwater with mineral weathering as a significant solute source, with a minor contribution from sea water likely from relict marine sediments. Subglacial hydrothermal activity upstream may also contribute solutes. Nutrients N and P are present at micromolar concentrations. Sediment porewaters from shallow cores (~ 40 cm depth) of the subglacial lake sediments indicate increasing solute concentration with depth, with up to ~ five times greater solute concentrations than in the lake water. The waters and sediment contain metabolically active organisms which are likely involved in elemental cycling within the lake system. Here we will discuss solute sources to the lake, solute dynamics within the lake waters and sediment, and the fluxes of solute and nutrients to the Ross Sea and their implications for these marine ecosystems.

  4. Getting to know the nearest stars: Intermittent radio bursts from Ross 614

    NASA Astrophysics Data System (ADS)

    Winterhalter, Daniel; Knapp, Mary; Bastian, Tim

    2017-04-01

    Radio observations have been used as a search tool for exoplanets since before the confirmed discovery of the first extrasolar planet. To date, there have been no definitive detections of exoplanets in the radio regime. We are engaged in an ongoing blind radio survey of the nearest star systems for exoplanetary radio emission. The goal of this survey is to obtain meaningful upper limits on radio emission from (or modulated by) sub-stellar companions of the nearest stars. Nearby stars are strongly preferred because they suffer the least from the dilution of potential radio signals by distance. Targets are selected by distance and observability (both LOFAR and VLA) only. Other properties of target stars, such as stellar type, are not considered to avoid biasing the search. Five survey targets, Procyon, GJ 1111, GJ 725, Ross 614, and UGPSJ072227.51, have been observed with the VLA telescope L- and S-band receivers. P-band observations are ongoing. Of particular interest are, at this time, our observation of the Ross 614 System. Ross 614 is an M-dwarf binary system at a distance of about 13 Ly, with an orbital period of 16.6 years. The binary companions are classified as flare stars because strong radio emission has been detected from the location of the system in previous work. Analyses are in progress to determine if the intermittent burst are similar to solar-type burst, and/or if there is any evidence for emissions from sub-stellar companions.

  5. On the dense water spreading off the Ross Sea shelf (Southern Ocean)

    NASA Astrophysics Data System (ADS)

    Budillon, G.; Gremes Cordero, S.; Salusti, E.

    2002-07-01

    In this study, current meter and hydrological data obtained during the X Italian Expedition in the Ross Sea (CLIMA Project) are analyzed. Our data show a nice agreement with previous data referring to the water masses present in this area and their dynamics. Here, they are used to further analyze the mixing and deepening processes of Deep Ice Shelf Water (DISW) over the northern shelf break of the Ross Sea. In more detail, our work is focused on the elementary mechanisms that are the most efficient in removing dense water from the shelf: either classical mixing effects or density currents that interact with some topographic irregularity in order to drop to deeper levels, or also the variability of the Antarctic Circumpolar Current (ACC) which, in its meandering, can push the dense water off the shelf, thus interrupting its geostrophic flow. We also discuss in detail the (partial) evidence of dramatic interactions of the dense water with bottom particulate, of geological or biological origin, thus generating impulsive or quasi-steady density-turbidity currents. This complex interaction allows one to consider bottom particular and dense water as a unique self-interacting system. In synthesis, this is a first tentative analysis of the effect of bottom particulate on the dense water dynamics in the Ross Sea.

  6. Applicability of highly branched isoprenoids as a sea ice proxy in the Ross Sea

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Hyun; Lee, Jae Il; Belt, Simon T.; Gal, Jong-Ku; Smik, Lukas; Shin, Kyung-Hoon

    2016-04-01

    Sea ice is an integral component of the polar climate system, constraining the effect of changing surface albedo, ocean-atmosphere heat exchanges, the formation of deep and intermediate waters that participate in driving the meridional overturning circulation and thus global climate. In recent years, a mono-unsaturated highly branched isoprenoid (HBI) alkene which is biosynthesised by certain sea ice diatoms during the spring bloom and, upon ice melt, deposited into underlying sediments, has been uniquely observed in Arctic sea ice and in Arctic sediments. Hence, the term IP25 (ice proxy with 25 carbon atoms) was proposed to distinguish this compound from other HBI isomers and has become an established proxy for the reconstruction of Arctic sea ice. In contrast, a monounsaturated HBI alkene, i.e. IP25, has not been observed in sea ice or sediments from the Antarctic. Hence, the application of diene and triene HBI concentrations and the resulting diene/triene (D/T) ratio was alternatively introduced as sea ice/open water indicators in the Southern Ocean. However, there is still lack of data covering the wide areas around the Antarctic, especially from the Ross Sea. Hence, we investigated surface sediment samples from the Ross Sea (n=14) collected during the R/V ARAON cruise in 2015 as well as from the Antarctic Peninsula (n=17) collected during several R/V ARAON cruises between 2001 and 2013. We will present our preliminary results and will discuss the applicability of the HBI in the Ross Sea.

  7. Foraging time and dietary intake by breeding ross's and lesser snow geese

    USGS Publications Warehouse

    Gloutney, M.L.; Alisauskas, R.T.; Afton, A.D.; Slattery, S.M.

    2001-01-01

    We compared foraging times of female Ross's (Chen rossii) and Lesser Snow Geese (Chen caerulescens caerulescens) breeding at Karrak Lake, NT, Canada and examined variation due to time of day and reproductive stage. We subsequently collected female geese that had foraged for known duration and we estimated mass of foods consumed during foraging bouts. Female Ross's Geese spent more time foraging (mean % ?? SE = 28.4 ?? 1.3%; P = 0.0002), on average, than did female Lesser Snow Geese (21.5 ?? 1.4%). Foraging time by female geese differed among reproductive stages, but differences were not consistent among time periods (stage-by-time block interaction, P=0.0003). Females spent considerably more time foraging during prelaying and laying than during incubation. Ross's Geese also spent a greater percent of time feeding (83.0??2.8%) during incubation recesses than did Lesser Snow Geese (60.9??3.6%). Consumption of organic matter during foraging bouts was minimal; estimated consumption averaged 9.6??4.0 and 12.4??4.6 g (mean ?? SE) dry mass/day before incubation and 5.9??2.0 and 5.7??2.1 g dry mass/day during incubation for Lesser Snow and Ross's Geese, respectively. Diets consisted primarily of mosses (bryophytes), Chickweed (Stellaria spp.) and Sedges (Carex spp.). Before incubation, eggshell consumption was estimated as 4.3??3.2 and 0.4??0.3 g dry mass/day for Lesser Snow and Ross's Geese, respectively; neither species consumed eggshell during incubation. We conclude that eggshell from nests of previous years is likely an important source of dietary calcium used to meet mineral demands of eggshell formation at Karrak Lake. Our findings of wide disparities between foraging time and food intake indicate that results from studies that do not directly measure intake rates remain equivocal. Finally, we propose four hypotheses accounting for foraging effort that evidently yields little nutritional or energetic benefit to geese nesting at Karrak Lake.

  8. Decadal Changes in Hydrography of the Southern Pacific Ocean and Ross Sea

    NASA Astrophysics Data System (ADS)

    Talley, L. D.; Carter, B.; Warner, M. J.; Swift, J. H.; Orsi, A. H.; Sloyan, B.

    2014-12-01

    Quasi-decadal hydrographic sections of the GO-SHIP program cross the world's oceans with the highest accuracy measurements, documenting temporal variability in physical and chemical properties. The central southern Pacific and Ross Sea have been surveyed regularly along GO-SHIP sections P16S (150W) and S4P (67S) since the first occupation in WOCE in 1992. Observed changes are consistent with anthropogenic forcing. The central Ross Sea gyre's bottom 1000 m is nearly adiabatic (well mixed), and well-ventilated based on chlorofluorocarbon (CFC) and sulfur hexafluoride observations (see Figure), and can be easily compared from one survey to the next. This Ross Sea bottom layer observed in March, 2014, on P16S continued to warm, with a monotonic increase over the 4 WOCE/GO-SHIP surveys thus far: 1992, 2005, 2011, and now 2014 (see Figure). Deep temperature has increased by 0.1°C since 1992, continuing the trend of enhanced global ocean deep warming in the Southern Ocean documented by Purkey/Johnson (2010) and IPCC AR5 WG1. The abyssal central Ross Sea waters also continued to freshen slightly. The upper ocean in the Ross Sea warmed, became more stratified, had higher nutrients and total carbon, and was less ventilated in terms of apparent oxygen utilization than in 2005. North of the Antarctic Circumpolar Current along 150W, the upper ocean's Subantarctic Mode Water became saltier, also continuing the subtropical trend of the past several decades (Durack/Wijffels 2010), with an apparently stronger incursion of saline subtropical waters that render it more salt and temperature stratified, ruling out a local deep mixed layer formation mechanism, with an increasing tendency towards double diffusive processes. The Antarctic Intermediate Water salinity minimum continued to freshen. The arrival in 2014 of CFC's at the ocean bottom between 32S and 40S indicates that the Antarctic Bottom Water there is about 40-50 years old. CFCs in the ocean's surface layer decreased, in

  9. Atmospheric forcing of sea ice anomalies in the Ross Sea Polynya region

    NASA Astrophysics Data System (ADS)

    Dale, Ethan; McDonald, Adrian; Rack, Wolfgang

    2016-04-01

    Despite warming trends in global temperatures, sea ice extent in the southern hemisphere has shown an increasing trend over recent decades. Wind-driven sea ice export from coastal polynyas is an important source of sea ice production. Areas of major polynyas in the Ross Sea, the region with largest increase in sea ice extent, have been suggested to produce the vast amount of the sea ice in the region. We investigate the impacts of strong wind events on polynyas and the subsequent sea ice production. We utilize Bootstrap sea ice concentration (SIC) measurements derived from satellite based, Special Sensor Microwave Imager (SSM/I) brightness temperature images. These are compared with surface wind measurements made by automatic weather stations of the University of Wisconsin-Madison Antarctic Meteorology Program. Our analysis focusses on the winter period defined as 1st April to 1st November in this study. Wind data was used to classify each day into characteristic regimes based on the change of wind speed. For each regime, a composite of SIC anomaly was formed for the Ross Sea region. We found that persistent weak winds near the edge of the Ross Ice Shelf are generally associated with positive SIC anomalies in the Ross Sea polynya area (RSP). Conversely we found negative SIC anomalies in this area during persistent strong winds. By analyzing sea ice motion vectors derived from SSM/I brightness temperatures, we find significant sea ice motion anomalies throughout the Ross Sea during strong wind events. These anomalies persist for several days after the strong wing event. Strong, negative correlations are found between SIC within the RSP and wind speed indicating that strong winds cause significant advection of sea ice in the RSP. This rapid decrease in SIC is followed by a more gradual recovery in SIC. This increase occurs on a time scale greater than the average persistence of strong wind events and the resulting Sea ice motion anomalies, highlighting the production

  10. Foraging time and dietary intake by breeding Ross's and Lesser Snow Geese.

    PubMed

    Gloutney, Mark L; Alisauskas, Ray T; Afton, Alan D; Slattery, Stuart M

    2001-03-01

    We compared foraging times of female Ross's (Chen rossii) and Lesser Snow Geese (Chen caerulescens caerulescens) breeding at Karrak Lake, NT, Canada and examined variation due to time of day and reproductive stage. We subsequently collected female geese that had foraged for known duration and we estimated mass of foods consumed during foraging bouts. Female Ross's Geese spent more time foraging (mean % ± SE =28.4±1.3%; P=0.0002), on average, than did female Lesser Snow Geese (21.5 ± 1.4%). Foraging time by female geese differed among reproductive stages, but differences were not consistent among time periods (stage-by-time block interaction, P=0.0003). Females spent considerably more time foraging during prelaying and laying than during incubation. Ross's Geese also spent a greater percent of time feeding (83.0±2.8%) during incubation recesses than did Lesser Snow Geese (60.9±3.6%). Consumption of organic matter during foraging bouts was minimal; estimated consumption averaged 9.6±4.0 and 12.4±4.6 g (mean ± SE) dry mass/day before incubation and 5.9±2.0 and 5.7±2.1 g dry mass/day during incubation for Lesser Snow and Ross's Geese, respectively. Diets consisted primarily of mosses (bryophytes), Chickweed (Stellaria spp.) and Sedges (Carex spp.). Before incubation, eggshell consumption was estimated as 4.3±3.2 and 0.4±0.3 g dry mass/day for Lesser Snow and Ross's Geese, respectively; neither species consumed eggshell during incubation. We conclude that eggshell from nests of previous years is likely an important source of dietary calcium used to meet mineral demands of eggshell formation at Karrak Lake. Our findings of wide disparities between foraging time and food intake indicate that results from studies that do not directly measure intake rates remain equivocal. Finally, we propose four hypotheses accounting for foraging effort that evidently yields little nutritional or energetic benefit to geese nesting at Karrak Lake.

  11. A case study of a Ross Ice Shelf Airstream event using high resolution observational data captured by SNOWWEB

    NASA Astrophysics Data System (ADS)

    Jolly, Ben; McDonald, Adrian

    2015-04-01

    The Ross Ice Shelf Airstream (RAS) is the dominant weather pattern over the Ross Ice Shelf in Antarctica. Characterised by a strong southerly flow over the ice shelf, the RAS plays a significant role in the northward transport of cold air from the interior of the continent out into the Ross Sea. As it passes by Ross Island - home to McMurdo Station and Scott Base - and out over the edge of the ice shelf, the RAS also helps to create and maintain the Ross Sea Polynya, the single largest contributor to sea ice growth in the Ross Sea region. Our area of interest is the McMurdo Ice Shelf, situated directly south of Ross Island and adjoining the north-western tip of the much larger Ross Ice Shelf. The terrain of this region is complex, with large mountains, islands, and cliffs dominating local flow. Additionally, severe weather - often experienced during a RAS event - can greatly impact human activity. These two factors make this region particularly interesting to study. During the 2013/14 austral summer season we deployed 14 weather stations on the McMurdo Ice Shelf, creating a dense spatial observational network. In combination with existing automatic weather stations and high resolution model output from the Antarctic Mesoscale Prediction System (AMPS), we present a case study of a three day RAS event observed in November 2013. We find that AMPS represents the RAS well in general, however at the local scale there are some large discrepancies between observed and forecast winds. Predominantly these are a result of errors in timing, with AMPS incorrectly forecasting 'lulls' in the RAS when none were observed and vice-versa. There also appear to be some differences between AMPS and observations regarding the split of the southerly RAS flow around Ross Island. The representation within AMPS of both Hut Point Peninsula - a small yet important orographic feature running south-west from Ross Island that blocks relatively weak flows - and the Windless Bight high pressure

  12. River meanders

    USGS Publications Warehouse

    Leopold, Luna Bergere; Langbein, Walter Basil

    1966-01-01

    The striking geometric regularity of a winding river is no accident. Meanders appear to be the form in which a river does the least work in turning; hence they are the most probable form a river can take

  13. An analysis of the Ross Ice Shelf low-level wind field using surface observations and modeling studies

    NASA Astrophysics Data System (ADS)

    Seefeldt, Mark William

    A dominant feature of the Ross Ice Shelf region wind field is the Ross Ice Shelf air stream (RAS). The RAS is a northward moving air stream in the lower atmosphere over the Ross Ice Shelf. The RAS is comprised of katabatic winds, barrier winds, and winds associated with the passage of cyclone and mesocyclones. An analysis of the surface wind field is done using automatic weather station (AWS) observations by dividing the wind field into dominant wind regimes. The dominant wind regimes are classified by identifying patterns in the wind speed and wind direction from AWS across the Ross Ice Shelf region. The results indicate that previous studies on the Ross Ice Shelf surface wind field, focusing on katabatic winds and barrier winds, represent less than half of the observed winds. An analysis of the presence and location of low-level jets (LLJs) across the Ross Ice Shelf region is presented based on the analysis of the archived real-time numerical weather prediction output. The method of self-organizing maps (SOMs) is used to objectively identify different patterns in column-averaged wind speed as an identifier to the location of LLJs. The results indicate three LLJs in the region. The largest and most dominant LLJ is along the Transantarctic Mountains by the Siple Coast and the southern end of the Ross Ice Shelf. The second LLJ extends from the base of Byrd Glacier and curves to the north passing by the eastern extremes of Ross Island. The third LLJ extends from the base of Reeves Glacier and curves to the north across the western Ross Sea. The low-level wind field is investigated to provide more insight into the RAS through the use of SOMs. Four generalized patterns are found in the low-level wind field. The patterns are associated with a weak synoptic environment, a Ross Sea cyclone, a Cape Colbeck cyclone, and an elongated cyclone near Cape Adare. A temporal sequence in the low-level wind field is presented based on an analysis of transitions in the low-level wind

  14. X-ray Ross filter method for impurity transport studies on DIII-D (abstract)

    NASA Astrophysics Data System (ADS)

    Bogatu, I. N.; Kim, J. S.; Egdell, D. H.; Snider, R. T.; Brooks, N. H.; Wade, M. R.; West, W. P.

    2001-01-01

    The injection of Ar into the region of the DIII-D divertor is a promising technique for energy dissipation (through radiation and collisions) and consequently for reduction of the heat load on the plates. An important problem related to this technique, is the inherent poisoning of the core plasma by migrating Ar. The Ar core contamination seems also to improve the thermal transport in an advanced operating mode of the tokamak. It is therefore of great importance to measure the evolution of the impurity concentration profile within the core plasma. This goal could be achieved by using the Ross filter method in conjunction with the existing x-ray diagnostics on DIII-D. A basic Ross filter system consists of two identical detectors placed behind two different x-ray absorbing foils looking at the same plasma volume. The foils are made of different elements or compounds with adjacent or nearly adjacent atomic numbers. Their accurate thickness causes the x-ray transmission curves of the two foils to be effectively identical over the entire energy range except within the narrow region between their absorption edges. Since the transmission characteristics of the foils above and below their absorption edges are the same, any difference in the two detected signals is proportional to the total x-ray power of the emission spectrum between these two edge energies. An x-ray Ross filter with its energy pass band centered on the Ar XVII Kα line at 3.14 keV has been designed. This allows for the discrimination of the Ar Kα line only, regardless of Ar ionization state, against any background radiation with energies outside the energy pass band. The Ross filter was installed in front of two of the fan shaped poloidal x-ray arrays on DIII-D. The first measurements showed very good discrimination against Ne, another injected impurity. Emissivity profile evolution of the Kα lines and Ar enhanced continuum within the energy pass band of the Ross filter can be determined from the x

  15. Analyses on Origin of positive gravity anomalies of sedimentary basins of the Ross Sea

    NASA Astrophysics Data System (ADS)

    Gao, Jinyao; Yang, Chunguo; Ji, Fei; Wang, Wei; Shen, Zhongyan

    2017-04-01

    We have adopted gridded products describing surface elevation, ice-thickness and the sea floor and subglacial bed elevation south of 60◦ S from Bedmap2 and north of 60◦ S from JGP95E to calculate Bouguer and isostatic gravity anomaly of the Ross Sea region based on the DTU10 free-air gravity anomaly.Taking a view of the free-air, Bouguer and isostatic gravity anomalies, it is unusual that high values overlay the Victoria Land Basin, Central Trough, Northern Basin and Northern Central Trough while basement highs are associated with low value. A number of studies have attributed the high gravity anomalies across the depocenters to high-density volcanics deep within the basins or magmatic intrusions within the region of the thinned crust or upper mantle (e. g., Edwards et al., 1987). According to the conclusion from Karner et al. (2005), the anticorrelation of gravity anomalies with sediment basement can be reproduced if the flexural strength of the lithosphere during the late Cretaceous rifting is significantly lower than the flexural strength of the lithosphere at the Oligocene and Neogene time of sedimentation. We note that the isostatic gravity anomalies are higher than the free-air gravity anomalies adjacent to the Transantarctic Mountains, and vice versa away from the Transantarctic Mountains. We may ignore the constraints offered by the tranditional isostasy in the local gravity studies of the Ross Sea basins, especially advancing the concept of high density material in the lower crust or upper mantle. In particular, the modeled gravity does not laterally integrate to zero, due to the existence of unbalanced forces induced by mantle. Along the outer shelf uplift zone surrouding Antarctica, the positive gravity belt has higher values in free-air gravity anomalies than those in isostatic gravity anomalies. Meanwhile, the positive gravity belt of isostatic gravity anomalies almost disappears in the background anomalies of 20 mGal to 10 mGal facing the

  16. Microbial response to different phytoplankton-derived dissolved organic matter sources in the Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Sipler, R. E.; Spackeen, J.; McQuaid, J.; Bertrand, E. M.; Roberts, Q. N.; Baer, S. E.; Hutchins, D. A.; Allen, A. E.; Bronk, D. A.

    2016-02-01

    Western Antarctic shelves are highly productive regions that play an important role in global carbon and nitrogen cycles, specifically serving as a critical sink for carbon dioxide. Fixed carbon is stored within the phytoplankton cell as particulate organic matter or released into the surrounding water as dissolved organic matter (DOM). These phytoplankton-derived sources of organic matter support higher trophic levels as well as heterotrophic bacterial growth and respiration. The composition of the phytoplankton-derived organic matter is a function of the taxa as well as the environmental conditions under which it is produced. Phytoplankton community composition within western Antarctic Seas changes throughout Austral spring and summer with early production dominated by ice algae, switching to pelagic diatoms and flagellates later in the season. The goal of this study was to compare the response of Ross Sea microbial communities to DOM produced by ice algae or late season diatoms, specifically recent isolates of Pseudo nitzschia obtained from the Ross Sea. During 5-day bioassay studies, exudates from a natural ice algal community and from Pseudo nitzschia sp. isolates were added to natural microbial communities collected from two different Ross Sea locations, an ice-edge and an ice-covered site. The bacterial response to the DOM additions was greatest in the ice-covered community with a 5 and 3-fold higher bacterial abundance in the ice algae DOM and Pseudo nitzschia DOM treatments, respectively, relative to the control. The ice edge bacterial community responded similarly to both sources with a 2-fold increase in bacterial abundance compared to the control. Unlike the bacterial response, there was little difference in chlorophyll a concentrations between treatments, indicating that phytoplankton growth was not stimulated or inhibited by our additions.

  17. Geology, geochronology and geochemistry of a basanitic volcano, White Island, Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Cooper, Alan F.; Adam, Lotte J.; Coulter, Roseanne F.; Eby, G. Nelson; McIntosh, William C.

    2007-09-01

    White Island, Ross Sea, Antarctica is a Plio-Pleistocene basanite to tephriphonolite shield volcano, forming part of the Erebus Province, McMurdo Volcanic Group. Four new 40Ar/ 39Ar dates extend the age of surface volcanism from a previously determined 0.17 Ma to 5.05 ± 0.31 Ma. A U/Pb age on zircon in an anorthoclasite nodule extends White Island magmatism back to 7.65 ± 0.69 Ma. Volcanism was predominantly subaerial with eruption of agglutinated spatter-clast breccias and lava flows from vents with a NNE structural alignment. An early phase of inferred subaqueous/subglacial activity formed pillow breccias. Two nunataks in the southern part of the island comprise basanitic tuff cones, composed of poorly bedded pyroclastic deposits dominated by sideromelane lapilli, and containing horizons rich in accretionary and armoured lapilli. Many of the basanites have compositions of near-primary magmas and contain an assortment of Cr-diopside and Al-augite suite mantle nodules, lower crustal gabbros, mafic granulites, and assorted megacrysts. Peridotites are dominated by spinel facies inclusions, but include plagioclase-spinel lherzolites derived from shallow mantle beneath the tectonically thinned and attenuated Ross Sea lithosphere. Mantle nodules contain accessory amounts of pale brown, metasomatic amphibole. Volcanic geochemistry is compatible with fractionation of olivine, pyroxene, titano-magnetite and minor apatite from a basanite parent yielding tephriphonolite residual liquids. Magmatism is focused along, or at the termination of, Cenozoic rift basins in the Ross Sea. The regional McMurdo Volcanic Group distribution and tectonic setting, and the history of Erebus Province volcanic centres are difficult to reconcile in terms of active mantle plumes. Instead, more randomly distributed magmatism is inferred to result from rift-related decompression melting of previously enriched mantle that may have been fertilized by plume interaction prior to Gondwana

  18. Legacy persistent organic pollutants including PBDEs in the trophic web of the Ross Sea (Antarctica).

    PubMed

    Corsolini, Simonetta; Ademollo, Nicoletta; Martellini, Tania; Randazzo, Demetrio; Vacchi, Marino; Cincinelli, Alessandra

    2017-10-01

    The ecological features of the Ross Sea trophic web are peculiar and different from other polar food webs, with respect to the use of habitat and species interactions; due to its ecosystem integrity, it is the world's largest Marine Protected Area, established in 2016. Polar organisms are reported to bioaccumulate lipophilic contaminant, viz persistent organic pollutants (POPs). Legacy POPs and flame retardants (polybrominated diphenyl ethers, PBDEs) were studied in key species of the Ross Sea (Euphausia superba, Pleuragramma antarctica) and their predators (Dissostichus mawsoni, Pygoscelis adeliae, Aptenodytes forsteri, Catharacta maccormicki, Leptonychotes weddellii). Gaschromatography revealed the presence of PCBs, HCB, DDTs, PBDEs in most of the samples; HCHs, dieldrin, Eldrin, non-ortho PCBs, PCDDs, PCDFs were detected only in some species. The average ∑PBDEs was 0.19-1.35 pg/g wet wt in the key-species and one-two order of magnitude higher in the predators. Penguins and skuas from an area where a long-term field camp is located showed higher BDE concentrations. The ΣDDTs was higher in the Antarctic toothfish (20 ± 6.73 ng/g wet wt) and in the South Polar skua (5.911 ± 3.425 ng/g wet wt). The TEQs were evaluated and the highest concentration was found in the Weddell seal, due to PCB169, 1,2,3,4,7,8-HxCDF, and 2,3,4,6,7,8-HxCDF. There was no significant relationship between the trophic level and the POP concentrations. Although low concentrations, organisms of the Ross Sea trophic web should be further studied: lack of information on some ecotoxicological features and human impacts including global change may distress the ecosystem with unpredictable effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Marine record of Holocene climate, ocean, and cryosphere interactions: Herbert Sound, James Ross Island, Antarctica

    NASA Astrophysics Data System (ADS)

    Minzoni, Rebecca Totten; Anderson, John B.; Fernandez, Rodrigo; Wellner, Julia Smith

    2015-12-01

    The sediment record offshore James Ross Island, northeast Antarctic Peninsula presents an unparalleled opportunity to directly compare marine and terrestrial climate records spanning the Holocene in maritime Antarctica. An 11 m drill core was collected between Herbert Sound and Croft Bay as part of the SHALDRIL NBP-0502 initiative and produced the southernmost sediment record from the eastern side of the AP. Thirty-eight radiocarbon ages are used to construct an age model of centennial-scale resolution. Multi-proxy records, including magnetic susceptibility, pebble content, particle size, total organic carbon, and diatom assemblages, were interrogated in the context of nearby Holocene-age ice core, lake, and drift records from James Ross Island. Differences in the timing and expression of Holocene events reflect marine controls on tidewater glaciers, such as water mass configurations and sea ice. Glacial behavior mimics ice core paleotemperatures during the Holocene, with the exception of distinct ocean warming events. Herbert Sound was fully occupied by grounded ice during the Last Glacial Maximum, and experienced rapid lift-off, followed by a floating ice phase. The canopy of floating ice receded by 10 ± 2.4 cal kyr BP, presumably in response to Early Holocene warming. Herbert Sound and Croft Bay fully deglaciated by 7.2 cal kyr BP, when the Mid Holocene Hypsithermal commenced and the sound became open and productive. An extreme peak in productivity ∼6.1 cal kyr BP indicates an oceanic warming event that is not reflected in atmospheric temperature or lacustrine sediment records. Increase in sea ice cover and ice rafting mark the onset of the Neoglacial ∼2.5 cal kyr BP, when pronounced atmospheric cooling is documented in the James Ross Island ice core. Our comparison facilitates more holistic understanding of atmosphere-ocean-cryosphere interactions that may aid predictions of glacial response to future warming and sea-level scenarios.

  20. Soil micromorphology, geochemistry and microbiology at two sites on James Ross Island, Maritime Antarctica

    NASA Astrophysics Data System (ADS)

    Meier, Lars A.; Krauze, Patryk; Prater, Isabel; Scholten, Thomas; Wagner, Dirk; Kühn, Peter; Mueller, Carsten W.

    2017-04-01

    Referring to the fundamental question in ecosystem research, how biotic and abiotic processes interact, only a few studies exist for polar regions that integrate microbiological and soil scientific studies . Soils comprise the complex structure and environment that fosters water storage and nutrient cycling determined by its unique chemical, physical and biological properties with respect to the specific climate and parent material. In the extreme environment of Antarctica, soil biological processes are primarily controlled by microbial communities (Bacteria, Archaea and Fungi), and thus microbiota may also determine soils chemical and physical properties in a landscape lacking higher plants at an average air temperature below 0°C. James Ross Island, Maritime Antarctica, offers a pristine laboratory and an exceptional opportunity to study pedogenesis without the influence of vascular plants and burrowing animals. We analysed micromorphological features, chemical and microbiological measures at two sites on James Ross Island (Brandy Bay and St. Martha Cove) with similar substrates (mostly fine-grained calcareous sandstones and siltstones of the Alpha Member of the Santa Martha Formation with varying amounts of conglomerates and mudstones) at similar topographic positions (small plateaus at similar elevation (80m a.s.l.)). The sites represent luv- and leeward conditions with respect to the main southwesterly winds. The climate on James Ross Island is to be described as semi-arid polar-continental, which is in clear contrast to the Southern Shetlands (e.g. King George Island) north of the Antarctic Peninsula. We will present first results of soil physical (bulk density, soil moisture and grains size distribution), pedochemical (SOC, total N and S, pH, CECeff, and pedogenic oxides) micromorphological and microbial analyses (Microbial DNA content, microbial abundances).

  1. Ambient Seismic Signals Observed in Iceberg?Filled Waters of the Ross Sea, Antarctica.

    NASA Astrophysics Data System (ADS)

    Macayeal, D. R.; Okal, E. A.; Aster, R. C.

    2006-12-01

    A two-year seismometer deployment on various icebergs in the Ross Sea and on the Ross Ice Shelf (PASSCAL project SOUTHBERG) have produced an unusual seismological "tone poem" constituting a sample of ambient conditions in an iceberg-covered, coastal sea of Antarctica. The original motivation of the project was to investigate the source of signals seen as T-phases in the equatorial Pacific [e.g., Talandier et al., 2002]. During the periods of continuous seismometer operation (i.e., during the October - April periods of 2003-4 and 2004-5 when photovoltaic charging systems kept seismometers in operation) on icebergs B15A, C16 and Nascent Iceberg (a site not yet calved from the Ross Ice Shelf), about 1300 events were observed (roughly one event per day). These events are attributed to the icebergs, and are loosely referred to as "iceberg tremor" due to their long duration (many hours) and spectral structure (e.g., characterized by clearly preferential frequencies in the 1-3 Hz range, accompanied by multiple harmonics of a variable-pitch fundamental). The purpose of this presentation is to give a general qualitative overview of the various categories of iceberg tremor, and to describe their relationship to other variables observed (e.g., iceberg drift velocity, iceberg-on-iceberg collision, iceberg-on-seabed scraping). Speculation on the cause or causes of iceberg tremor will be postponed pending further study. Suggestions as to the relationship between the ambient tone poem of iceberg-covered waters and hydro-acoustic and seismic signals seen in the ocean beyond Antarctica will be offered.

  2. Insights into accumulation variability over the last 2000 years at James Ross Island, Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Massam, A.; Mulvaney, R.; McConnell, J.; Abram, N.; Arienzo, M. M.; Whitehouse, P. L.

    2016-12-01

    The James Ross Island ice core, drilled to 364 m on the northern tip of the Antarctic Peninsula, preserves a climate record that spans beyond the Holocene period to the end of the last glacial maximum (LGM). Reanalysis of the ice core using high-resolution continuous flow analysis (CFA) highlighted errors in the identification of events of known age that had been used to constrain the earlier chronology. The new JRI2 chronology is annual layer counted to 300 years, with the remaining profile reconstructed using a new age-depth model that is tied to age horizons identified in the annual-layer counted WAIS Divide ice core record. An accurate age-depth profile requires reliable known-age horizons along the ice core profile. In addition, these allow us to determine a solution for the accumulation history and rate of compaction due to vertical strain. The accuracy of the known-age constraints used in JRI2 allows only a small uncertainty in the reconstruction of the most recent 2000 years of accumulation variability. Independently, the surface temperature profile has been estimated from the stable water isotope profile and calibrated to borehole temperature observations. We present the accumulation, vertical thinning and temperature history interpreted from the James Ross Island ice core for the most recent 2000 years. JRI2 reconstructions show accumulation variability on a decadal to centennial timescale up to 20% from the present-day mean annual accumulation rate of 0.63 m yr-1. Analysis of the accumulation profile for James Ross Island offers insight into the sensitivity of accumulation to a change in surface temperature, as well as the reliability of the assumed relationship between accumulation and surface temperature in climate reconstructions using stable water isotope proxies.

  3. Structural map of flow variability and propagation behavior in the Ross Ice Shelf

    NASA Astrophysics Data System (ADS)

    LeDoux, C. M.; Hulbe, C. L.

    2011-12-01

    Fracture geometries in the Ross Ice Shelf, observable using visible band satellite imagery from the MODIS Mosaic of Antarctica (MOA) and the Landsat Image Mosaic of Antarctica (LIMA) provide a unique opportunity to study fracture propagation behavior and discharge variability in the ice streams and outlet glaciers feeding the shelf. Propagation is driven by changes in fracture length, near-field stress conditions, and the material properties of the ice. Changes in ice stream discharge and the development of "sticky spots," in both ice streams and within the shelf, lead to redirection of flow, changes in lateral gradients of ice velocity, and the propagation of fractures in response to changes in near-field stresses. The propagation behaviors most commonly observed in the ice shelf are the growth in the transverse direction of a fracture that formed within a shear zone and mechanical interactions between adjacent fracture tips. We use fracture mechanics theory and remote-sensed imagery to categorize fracture patterns and longitudinal zones of fractured ice in the Ross Ice Shelf. Near current sites of formation, simple fracture geometries and principal stresses are used to illustrate physical processes related to the formation and propagation of fractures. To compute flow lines and principal stresses, we derive a velocity map of the Ross Ice Shelf by merging two velocity datasets using a combination of statistical methods. A structural map of fracture geometries, relict shear margins, and structural boundaries is constructed. Using the ice shelf features, present-day flow lines, and principal stresses, we investigate the manner in which principal stresses affect fracture formation and propagation behavior and the variability of ice stream discharge into the shelf.

  4. Late Quaternary fluctuations of biogenic component fluxes on the continental slope of the Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Ceccaroni, L.; Frank, M.; Frignani, M.; Langone, L.; Ravaioli, M.; Mangini, A.

    1998-11-01

    A sediment core, collected from the western part of the continental slope of the Ross Sea at 2380 m water depth, records events of the last two climatic cycles (250 kyr). A 230Th ex-based chronology was obtained and boundaries of the isotope stages were set assuming that biological productivity was enhanced during periods of less ice cover. Then, 230Th ex0, organic carbon, biogenic silica and biogenic Ba distributions were compared to the glacial-interglacial stage boundaries and corresponding ages of the δ 18O record of Martinson et al. [Martinson, D.G., Pisias, N.G., Hays, J.D., Imbrie, J., Moore, T.C., Jr., Shackleton, N.J, 1987. Age dating and the orbital theory of the ice ages: development of a high-resolution 0 to 300,000-year chronostratigraphy. Quaternary Research, 27: 1-29]. Sediment accumulation rates ranged between 1.2 cm kyr -1 in the isotope stage 6 and 3.8 cm kyr -1 during the Holocene. Variations in the concentrations and fluxes of organic carbon, biogenic Ba, biogenic silica and Mn gave information on palaeoclimate changes. Processes of sediment redistribution in the Ross Sea margin were enlightened from a comparison of the measured and expected fluxes of 230Th ex. Calculation of the focusing-corrected accumulation rates of biogenic Ba enabled us to evaluate the export palaeoproductivity. Corrected accumulation rates of biogenic components and calculated palaeoproductivities were low, compared to the Antarctic Polar Front in the Atlantic sector, throughout the last two climatic cycles. Glacial-interglacial changes of sea ice cover and ventilation of the Ross Sea were probably major causes of variations in biogenic particle flux and distribution of redox-sensitive elements within the sediment column.

  5. Chili Cookoff: Unique Ingredients Prove Successful in Ross Smith’s Big Pot of Chili | Poster

    Cancer.gov

    By Ashley DeVine, Staff Writer If the past is any indication, judges at the Protective Services Chili Cookoff give high marks for chili recipes containing unique or uncommon ingredients. Previous winning recipes have included ingredients such as black beans, pumpkin, pineapple, pork loin, and even bourbon. Judges at the 12th annual event, held Jan. 5, continued this tradition by voting for Ross Smith’s Big Pot of Chili, which featured three types of meat, four different sauces, baker’s chocolate, and parmesan rind.  

  6. Outcomes of the Ross procedure in patients with an accompanying ascending aortic aneurysm.

    PubMed

    Karaskov, A M; Bogachev-Prokofiev, A V; Sharifulin, R M; Demin, I I; Zheleznev, S I; Open, A B; Pivkin, A N

    2016-01-01

    Analysed in the article are the results of the Ross procedure in patients presenting with dilatation of the ascending portion of the aorta. A combination of aortic valve defects with dilatation of the ascending aorta of more than 45 mm supposes simultaneous prosthetic repair of the aortic valve and ascending aorta. The most common surgical procedure remains the Bentall-DeBono operation whose main disadvantage is associated with implantation of a mechanical prosthesis and the necessity of lifelong anticoagulant therapy. An alternative method is the Ross procedure demonstrating low risk of thromboembolic complications and freedom from anticoagulant therapy. Over the period from 2002 to April 2015, specialists of the Novosibirsk Scientific Research Institute of Circulatory Pathology named after Academician E.N. Meshalkin carried out a total of 162 Ross procedures in patients presenting with accompanying dilatation of the ascending aorta (more than 45 mm). The mean diameter of the aorta at the level of Valsalva sinuses amounted to 45.6±8.6 mm, with that of the ascending aortic portion equalling 53.4±7.8 mm. The technique of total replacement of the aortic root was used in all cases. When the aneurysm extended to distal portions of the ascending aorta, additionally performed were the following procedures: in 24 patients--reduction aortoplasty, in 6 patients--replacement of the resected aorta with an insert from xenopericardium, and in 2 patients with a vascular graft. The average duration of follow up amounted to 40.1±21.6 months. Ten patients were subjected to repeat operations for autograft dysfunction. There were no reoperations on the ascending portion of the aorta. The regression analysis revealed that predictors of the development of autograft dysfunction were the baseline dilatation of the fibrous ring (FR) of the aortic valve of more than 27 mm (p=0.04) and uncorrected arterial hypertension in the postoperative period (p=0.03). In the group of patients with

  7. Diet and trophic niche of Antarctic silverfish Pleuragramma antarcticum in the Ross Sea, Antarctica.

    PubMed

    Pinkerton, M H; Forman, J; Bury, S J; Brown, J; Horn, P; O'Driscoll, R L

    2013-01-01

    The diet of Antarctic silverfish Pleuragramma antarcticum was evaluated by examining stomach contents of specimens collected in the Ross Sea (71°-77° S; 165°-180° E) in January to March 2008. Pleuragramma antarcticum (50-236 mm standard length, L(S)) and prey items were analysed for stable-isotopic composition of carbon and nitrogen. According to index of relative importance (I(RI) ), which incorporates frequency of occurrence, mass and number of prey items, the most important prey items were copepods (81%I(RI) over all specimens), predominantly Metridia gerlachei and Paraeuchaeta sp., with krill and fishes having low I(RI) (2·2 and 5·6%I(RI) overall). According to mass of prey (M) in stomachs, however, fishes (P. antarcticum and myctophids) and krill dominated overall diet (48 and 22%M, respectively), with copepods being a relatively minor constituent of overall diet by mass (9·9%M). Piscivory by P. antarcticum occurred mainly in the extreme south-west of the region and near the continental slope. Krill identified to species level in P. antarcticum stomachs were predominantly Euphausia superba (14·1%M) with some Euphausia crystallophorias (4·8%M). Both DistLM modelling (PRIMER-permanova+) on stomach contents (by I(RI)) and stepwise generalized linear modelling on stable isotopes showed that L(S) and location were significant predictors of P. antarcticum diet. Postlarval P. antarcticum (50-89 mm L(S)) consumed exclusively copepods. Juvenile P. antarcticum (90-151 mm L(S)) consumed predominantly krill and copepods by mass (46 and 30%M, respectively). Small adult P. antarcticum (152-178 mm L(S)) consumed krill, fishes and copepods (37, 36 and 15%M, respectively). Large adult P. antarcticum (179-236 mm L(S)) consumed predominantly fishes and krill (55 and 17%M, respectively), especially in the north (near the Ross Sea slope) and in the SW Ross Sea. Amphipods were occasionally important prey items for P. antarcticum (western Ross Sea, 39%M). General

  8. The relevance of buttressing for Filchner-Ronne and Ross Ice Shelf

    NASA Astrophysics Data System (ADS)

    Reese, Ronja; Gudmundsson, Hilmar; Levermann, Anders; Winkelmann, Ricarda

    2016-04-01

    Sub-shelf melting is an important component of Antarctica's mass budget. Although thinning of ice shelves does not directly contribute to sea-level rise, it may have a significant indirect impact through the potential of ice shelves to buttress their adjacent ice sheet. This is clearly seen in recent observations, e.g. in the Amundsen region (Pritchard et al., 2012) or at the Southern Antarctic Peninsula (Wouters et al, 2015) where increased ice loss of the adjacent upstream drainage basins is attributed to enhanced sub-shelf melting. In the extreme case, the complete disintegration of an ice shelf, e.g. during the calving events of Larsen A and B in 1995 and 2002, respectively, the adjacent ice streams subsequently accelerated significantly (Scambos et al., 2014). Here, we investigate the importance of buttressing using the finite-element, shallow-stream approximation numerical model Úa. We derive transfer functions for an idealized setup (Gudmundsson et al. 2012) and the Filchner-Ronne and Ross Ice Shelf. They allow for the computation of instantaneous changes in velocities to thickness perturbation patterns. Based on the transfer functions, we calculate the sensitivity of flux across the grounding line to regional varying melting patterns for the idealized setup and for Filchner-Ronne and Ross Ice Shelf. We find that the immediate response of velocities in the ice shelf-ice sheet system to changes in sub-shelf melting can be understood as the interaction of two effects: On the one hand, the spreading rate is a function of local ice thickness, indicating that a thinning of the ice shelf reduces velocities. On the other hand, ice shelf thinning weakens its ability to buttress, and thus enhances velocities. These two processes compete, leading to a complex pattern of velocity changes within the ice shelf. We find - both in the idealized setup and for Ross and Filchner-Ronne Ice Shelves - that the reduction in buttressing is dominating the velocity changes in the

  9. STS-110 M.S. Smith, Ross, and Walheim in Atlantis during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- (Left to right) STS-110 Mission Specialists Steven Smith, Jerry Ross and Rex Walheim settle into their seats aboard Space Shuttle Atlantis prior to a simulated launch countdown. The simulation is part of Terminal Countdown Demonstration Test activities. TCDT also includes emergency egress training and is held at KSC prior to each Space Shuttle flight. Scheduled for launch April 4, the 11-day mission will feature Shuttle Atlantis docking with the International Space Station (ISS) and delivering the S0 truss, the centerpiece-segment of the primary truss structure that will eventually extend over 300 feet.

  10. STS-110 M.S. Ross and Smith in M-113 personnel carrier during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- With STS-110 Mission Specialists Jerry Ross (far left) and Steven Smith (third from left) on board, Commander Michael Bloomfield scatters dust as he practices driving the M-113 armored personnel carrier. The driving is part of Terminal Countdown Demonstration Test activities, which include emergency egress training and a simulated launch countdown. The TCDT is held at KSC prior to each Space Shuttle flight. Scheduled for launch April 4, the 11-day mission will feature Shuttle Atlantis docking with the International Space Station (ISS) and delivering the S0 truss, the centerpiece-segment of the primary truss structure that will eventually extend over 300 feet.

  11. STS-110 M.S. Smith and Ross in slidewire basket during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-110 Mission Specialists Steven L. Smith (left) and Jerry L. Ross (right) get ready to climb out of the slidewire basket, part of emergency egress equipment on the launch pad.. The crew is taking part in Terminal Countdown Demonstration Test activities, which also include a simulated launch countdown, held at KSC prior to each Space Shuttle flight. Scheduled for launch April 4, the 11-day mission will feature Shuttle Atlantis docking with the International Space Station (ISS) and delivering the S0 truss, the centerpiece-segment of the primary truss structure that will eventually extend over 300 feet.

  12. STS-110 M.S. Ross in M-113 personnel carrier during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-110 Mission Specialist Jerry Ross waits his turn at driving the M-113 armored personnel carrier, part of Terminal Countdown Demonstration Test activities. In the background, right, is Mission Specialist Lee Morin. TCDT includes emergency egress training and a simulated launch countdown, and is held at KSC prior to each Space Shuttle flight. Scheduled for launch April 4, the 11-day mission will feature Shuttle Atlantis docking with the International Space Station (ISS) and delivering the S0 truss, the centerpiece-segment of the primary truss structure that will eventually extend over 300 feet.

  13. Moses presages Kubler-Ross: five stages in accepting death, as seen in the midrash.

    PubMed

    Berkowitz, M C; Knight, L

    2001-11-01

    This paper elucidates and explains an ancient midrash (rabbinic interpretation of a biblical text) through the lens of modern psychological theory. The midrash describes Moses' reactions to his approaching death. The paper points out that these reactions anticipate the five classic stages, described by Elizabeth Kubler-Ross, of coming to accept terminal illness: denial, anger, bargaining, depression and acceptance. The article shows the ancient rabbis' sensitivity to human feeling and the universal nature of human reaction through the dialogue and reactions they attribute to Moses. Finally, it shows how using this midrash offers a constructive model for approaching death, for Jewish and non-Jewish patients alike, as well as their caregivers.

  14. Newman and Ross work on the Early Communications System in Node 1

    NASA Image and Video Library

    2013-11-19

    STS088-334-033 (4-15 Dec. 1998) --- Astronauts Jerry L. Ross (on left with camera) and James H. Newman, both mission specialists, work in the Unity Module (Node 1). This task was designed to complete the assembly of an early S-band communications system that will allow flight controllers in Houston, Texas, to send commands to Unity's systems and to keep tabs on the health of the station with a more extensive communications capability than exists through Russian ground stations.

  15. STS-37 Mission Specialist Ross in OV-104's payload bay (PLB) during EVA

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-37 Mission Specialist (MS) Jerry L. Ross, suited in extravehicular mobility unit (EMU), peers into Atlantis', Orbiter Vehicle (OV) 104's, aft flight deck viewing window while performing emergency extravehicular activity (EVA) procedures in the payload bay (PLB). The unscheduled EVA was necessary to manually extend the Gamma Ray Observatory's (GRO's) high gain antenna (HGA). The GRO grappled by the remote manipulator system (RMS) end effector and held above the PLB is visible in the background. The entire scene is backdropped against the blue and white surface of the Earth.

  16. STS-110 M.S. Ross in M-113 personnel carrier during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-110 Mission Specialist Jerry Ross waits his turn at driving the M-113 armored personnel carrier, part of Terminal Countdown Demonstration Test activities. In the background, right, is Mission Specialist Lee Morin. TCDT includes emergency egress training and a simulated launch countdown, and is held at KSC prior to each Space Shuttle flight. Scheduled for launch April 4, the 11-day mission will feature Shuttle Atlantis docking with the International Space Station (ISS) and delivering the S0 truss, the centerpiece-segment of the primary truss structure that will eventually extend over 300 feet.

  17. Chili Cookoff: Unique Ingredients Prove Successful in Ross Smith’s Big Pot of Chili | Poster

    Cancer.gov

    By Ashley DeVine, Staff Writer If the past is any indication, judges at the Protective Services Chili Cookoff give high marks for chili recipes containing unique or uncommon ingredients. Previous winning recipes have included ingredients such as black beans, pumpkin, pineapple, pork loin, and even bourbon. Judges at the 12th annual event, held Jan. 5, continued this tradition by voting for Ross Smith’s Big Pot of Chili, which featured three types of meat, four different sauces, baker’s chocolate, and parmesan rind.  

  18. STS-110 M.S. Ross and Smith in M-113 personnel carrier during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- With STS-110 Mission Specialists Jerry Ross (far left) and Steven Smith (third from left) on board, Commander Michael Bloomfield scatters dust as he practices driving the M-113 armored personnel carrier. The driving is part of Terminal Countdown Demonstration Test activities, which include emergency egress training and a simulated launch countdown. The TCDT is held at KSC prior to each Space Shuttle flight. Scheduled for launch April 4, the 11-day mission will feature Shuttle Atlantis docking with the International Space Station (ISS) and delivering the S0 truss, the centerpiece-segment of the primary truss structure that will eventually extend over 300 feet.

  19. STS-110 M.S. Smith and Ross in slidewire basket during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- STS-110 Mission Specialists Steven L. Smith (left) and Jerry L. Ross (right) get ready to climb out of the slidewire basket, part of emergency egress equipment on the launch pad.. The crew is taking part in Terminal Countdown Demonstration Test activities, which also include a simulated launch countdown, held at KSC prior to each Space Shuttle flight. Scheduled for launch April 4, the 11-day mission will feature Shuttle Atlantis docking with the International Space Station (ISS) and delivering the S0 truss, the centerpiece-segment of the primary truss structure that will eventually extend over 300 feet.

  20. STS-110 M.S. Smith, Ross, and Walheim in Atlantis during TCDT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- (Left to right) STS-110 Mission Specialists Steven Smith, Jerry Ross and Rex Walheim settle into their seats aboard Space Shuttle Atlantis prior to a simulated launch countdown. The simulation is part of Terminal Countdown Demonstration Test activities. TCDT also includes emergency egress training and is held at KSC prior to each Space Shuttle flight. Scheduled for launch April 4, the 11-day mission will feature Shuttle Atlantis docking with the International Space Station (ISS) and delivering the S0 truss, the centerpiece-segment of the primary truss structure that will eventually extend over 300 feet.

  1. Remote sensing study of land use and sedimentation in the Ross Barnett Reservoir, Jackson, Mississippi area

    NASA Technical Reports Server (NTRS)

    Mealor, W. T., Jr.; Pinson, T. W.; Wertz, D. L.; Hoskin, C. M.; Williams, D. C.

    1972-01-01

    This multi-year study is aimed at focusing on the recognition of sediment and other affluents in a selected area of the Ross Barnett Reservoir. The principle objectives are the determination of land use types, effect of land use on erosion, and the correlation of sediment with land use in the area. The I2S multi-band imagery was employed in conjunction with ground truth data for both water and land use studies. The selected test site contains approximately forty square miles including forest, open land, and water in addition to residential and recreational areas.

  2. The effects of changing winds and temperatures on the oceanography of the Ross Sea in the 21st century

    NASA Astrophysics Data System (ADS)

    Smith, Walker O.; Dinniman, Michael S.; Hofmann, Eileen E.; Klinck, John M.

    2014-03-01

    The Ross Sea is critically important in regulating Antarctic sea ice and is biologically productive, which makes changes in the region's physical environment of global concern. We examined the effects of projected changes in atmospheric temperatures and winds on aspects of the ocean circulation likely important to primary production using a high-resolution sea ice-ocean-ice shelf model of the Ross Sea. The modeled summer sea-ice concentrations decreased by 56% by 2050 and 78% by 2100. The duration of shallow mixed layers over the continental shelf increased by 8.5 and 19.2 days in 2050 and 2100, and the mean summer mixed layer depths decreased by 12 and 44%. These results suggest that the annual phytoplankton production in the future will increase and become more diatomaceous. Other components of the Ross Sea food web will likely be severely disrupted, creating significant but unpredictable impacts on the ocean's most pristine ecosystem.

  3. Mixed-phase cloud radiative properties over Ross Island, Antarctica: The influence of various synoptic-scale atmospheric circulation regimes

    NASA Astrophysics Data System (ADS)

    Scott, Ryan C.; Lubin, Dan

    2014-06-01

    Spectral downwelling shortwave irradiance measurements made beneath overcast stratiform cloud decks at Ross Island, Antarctica (77.5°S, 167°E), are used in conjunction with discrete ordinates-based radiative transfer simulations to examine how mixed-phase clouds influence shortwave irradiance at the surface during austral spring-summer. From 10 October 2012 until 4 February 2013, an Analytical Spectral Devices (ASD, Inc.) spectroradiometer deployed at the Arrival Heights (77.82°S, 166.65°E) laboratory of McMurdo Station measured in 1 min averages the downwelling spectral hemispheric (direct plus diffuse) irradiance spanning visible (VIS) and near-infrared regions of the solar spectrum, from 350 to 2200 nm. Conservative-scattering cloud optical depth τc is retrieved in the interval 1022-1033 nm, where the albedo of the snow-covered surface is lower than at VIS wavelengths. The impact of liquid versus mixed-phase cloud properties on the surface shortwave energy budget is discerned using irradiances in the 1.6 μm window. Five case studies employ NASA A-Train satellite and ancillary meteorological data sets to investigate the macrophysical, microphysical, and shortwave radiative characteristics of clouds possessing distinct meteorological histories. Cloud systems within marine air masses arriving at Ross Island after transiting the West Antarctic ice sheet (WAIS) and the Ross Ice Shelf are radiatively dominated by the ice phase. In contrast, moist marine air moving directly onshore from the Ross Sea brings low clouds with a stronger influence of liquid water. Deep cyclonic disturbances over the Ross Sea are seen to be limited in their ability to deliver significant moisture as far south as Ross Island, where clouds are mainly optically thin.

  4. Evaluation of the Ross fast solution of Richards’ equation in unfavourable conditions for standard finite element methods

    NASA Astrophysics Data System (ADS)

    Crevoisier, David; Chanzy, André; Voltz, Marc

    2009-06-01

    Ross [Ross PJ. Modeling soil water and solute transport - fast, simplified numerical solutions. Agron J 2003;95:1352-61] developed a fast, simplified method for solving Richards' equation. This non-iterative 1D approach, using Brooks and Corey [Brooks RH, Corey AT. Hydraulic properties of porous media. Hydrol. papers, Colorado St. Univ., Fort Collins; 1964] hydraulic functions, allows a significant reduction in computing time while maintaining the accuracy of the results. The first aim of this work is to confirm these results in a more extensive set of problems, including those that would lead to serious numerical difficulties for the standard numerical method. The second aim is to validate a generalisation of the Ross method to other mathematical representations of hydraulic functions. The Ross method is compared with the standard finite element model, Hydrus-1D [Simunek J, Sejna M, Van Genuchten MTh. The HYDRUS-1D and HYDRUS-2D codes for estimating unsaturated soil hydraulic and solutes transport parameters. Agron Abstr 357; 1999]. Computing time, accuracy of results and robustness of numerical schemes are monitored in 1D simulations involving different types of homogeneous soils, grids and hydrological conditions. The Ross method associated with modified Van Genuchten hydraulic functions [Vogel T, Cislerova M. On the reliability of unsaturated hydraulic conductivity calculated from the moisture retention curve. Transport Porous Media 1988;3:1-15] proves in every tested scenario to be more robust numerically, and the compromise of computing time/accuracy is seen to be particularly improved on coarse grids. Ross method run from 1.25 to 14 times faster than Hydrus-1D.

  5. The Roosevelt Island Climate Evolution (RICE) Project - Did the Ross Ice Shelf Collapse During MIS 5e?

    NASA Astrophysics Data System (ADS)

    Bertler, N. A. N.; Conway, H.; Dahl-Jensen, D.; Blunier, T.; Brook, E.; Dadic, R.; Delmonte, B.; Dongqi, Z.; Edwards, R.; Emanuelsson, D. B.; Fudge, T. J.; Golledge, N.; Hindmarsh, R. C. A.; Hawley, R. L.; Kipfstuhl, S.; Kjær, H. A.; Kurbatov, A.; Lee, J.; Mayewski, P. A.; Naish, T.; Neff, P. D.; Scherer, R. P.; Severinghaus, J. P.; Simonsen, M. F.; Steig, E. J.; Tuohy, A.; Vallelonga, P. T.; Waddington, E. D.

    2014-12-01

    Geological evidence and modelling experiments suggest that the removal of ice shelves from marine based ice sheets can lead to catastrophic collapse. Roosevelt and Ross Islands are thought to be key stabilization anchors for the Ross Ice Shelf and thus the West Antarctic Ice Sheet. As part of the Roosevelt Island Climate Evolution (RICE) project, a 763m deep ice core was recovered during 2011-2013 from Roosevelt Island, at the northern edge of the Ross Ice Shelf. The ice at Roosevelt Island is grounded 210m below sea level and accumulates in situ, with the Ross Ice Shelf flowing around the rise. High resolution radar surveys show a well developed Raymond Bump at the divide of the ice dome. With the conclusion of the RICE core processing campaign in July 2014, a preliminary age model is developed using annual layer count, volcanic ash layers; and high resolution methane data tied to the WAIS Divide ice core record, and a glacial flow model. Here we show preliminary data spanning over 100 ka including evidence of ice from the Eemian period (MIS 5e) at the base of the core. The presence of Eemian ice in the RICE record raises the question: how much of the Ross Ice Shelf and West Antarctic Ice Sheet collapsed during the last interglacial, when global sea level was 4-8m higher than today? We discuss reconstructions of sea surface and air temperature, sea ice extent, atmospheric circulation patterns, and ice shelf retreat. An ensemble of sensitivity modelling experiments is used to determine thresholds for the removal of ice on Roosevelt Island and correlated grounding line and ice volume changes of the Ross Ice Shelf and the West Antarctic Ice Sheet.

  6. STS-55 MS1/PLC Ross and Payload Specialist Walter work in SL-D2 module

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-55 Mission Specialist 1 (MS1) and Payload Commander (PLC) Jerry L. Ross floats near cycle ergometer and Rack 9 Anthrorack (AR) (Human Physiology Laboratory) as German Payload Specialist 1 Ulrich Walter reviews a checklist in front of Rack 11 Experiment Rack. These experiment stations and the crewmembers are in the shirt-sleeve environment of the Spacelab Deutsche 2 (SL-D2) science module onboard the Earth-orbiting Columbia, Orbiter Vehicle (OV) 102. In the background is the SL-D2 aft end cone. Behind Ross and Walter is Rack 12 Experiment Rack with Baroreflex (BA).

  7. Supplement Analysis for the Transmission System Vegetation Management Program FEIS (DOE/EIS-0285/SA-117 - Ross Complex)

    SciTech Connect

    Stratton, Elaine

    2003-01-16

    Vegetation Management for the non-electric portions of the Bonneville Power Administration’s Ross Complex. BPA proposes to manage and maintain grounds and landscaping in the non-electrical portions of the Ross Facility. Vegetation management at the Facility shall include: 1) bare ground management of graveled storage areas, perimeter roads and parking areas; 2) mechanical and/or spot herbicide control of some broad leafs and noxious weeds; 3) mowing, fertilizing, and broadleaf control of landscaped lawn areas; 4) weed control in ornamental shrub areas; and 4) areas requiring only mechanical control to manage unwanted grasses, and shrubs.

  8. STS-55 MS1/PLC Ross and Payload Specialist Walter work in SL-D2 module

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-55 Mission Specialist 1 (MS1) and Payload Commander (PLC) Jerry L. Ross floats near cycle ergometer and Rack 9 Anthrorack (AR) (Human Physiology Laboratory) as German Payload Specialist 1 Ulrich Walter reviews a checklist in front of Rack 11 Experiment Rack. These experiment stations and the crewmembers are in the shirt-sleeve environment of the Spacelab Deutsche 2 (SL-D2) science module onboard the Earth-orbiting Columbia, Orbiter Vehicle (OV) 102. In the background is the SL-D2 aft end cone. Behind Ross and Walter is Rack 12 Experiment Rack with Baroreflex (BA).

  9. Increase of the Antarctic Sea Ice Extent is highly significant only in the Ross Sea

    NASA Astrophysics Data System (ADS)

    Yuan, Naiming; Ding, Minghu; Ludescher, Josef; Bunde, Armin

    2017-01-01

    In the context of global warming, the question of why Antarctic sea ice extent (SIE) has increased is one of the most fundamental unsolved mysteries. Although many mechanisms have been proposed, it is still unclear whether the increasing trend is anthropogenically originated or only caused by internal natural variability. In this study, we employ a new method where the underlying natural persistence in the Antarctic SIE can be correctly accounted for. We find that the Antarctic SIE is not simply short-term persistent as assumed in the standard significance analysis, but actually characterized by a combination of both short- and long-term persistence. By generating surrogate data with the same persistence properties, the SIE trends over Antarctica (as well as five sub-regions) are evaluated using Monte-Carlo simulations. It is found that the SIE trends over most sub-regions of Antarctica are not statistically significant. Only the SIE over Ross Sea has experienced a highly significant increasing trend (p = 0.008) which cannot be explained by natural variability. Influenced by the positive SIE trend over Ross Sea, the SIE over the entire Antarctica also increased over the past decades, but the trend is only at the edge of being significant (p = 0.034).

  10. Skeletal and isotopic composition and paleoclimatic significance of late Pleistocene carbonates, Ross Sea, Antarctica

    SciTech Connect

    Taviani, M. ); Reid, D.E.; Anderson, J.B. )

    1993-01-01

    Carbonates cover an extensive area of the northwestern Ross Sea continental shelf. Radiocarbon dates yield late Pleistocene (stage 3) ages for these deposits, hence the carbonates appear to be correlative with widespread tills and glacial marine deposits in the region. Four carbonate facies are recognized on the basis of skeletal composition: a barnacle/foraminifer facies, a muddy bryozoan facies, a bryozoan/barnacle/pelecypod/foraminifer facies, and a planktonic foraminiferal facies. These deposits occur on the shelf and upper slope, while carbonate turbidities derived from them occur on the adjacent continental slope and rise. Compositional analyses of Ross Sea carbonates lend support to previously recognized criteria for identifying cold water carbonates. These include: (1) the presence of an associated ice-rafted component (including dropstones); (2) a dominance of calcite relative to other carbonate minerals (the remaining fraction consists solely of aragonite); (3) allochems that are entirely skeletal; and (4) heavy oxygen isotopic compositions (in the range of +3.0 to +5.1% PDB).

  11. Krill distribution in relation to environmental parameters in mesoscale structures in the Ross Sea

    NASA Astrophysics Data System (ADS)

    Leonori, Iole; De Felice, Andrea; Canduci, Giovanni; Costantini, Ilaria; Biagiotti, Ilaria; Giuliani, Giordano; Budillon, Giorgio

    2017-02-01

    Krill, a key pelagic resource of the Antarctic food web, provides an important link between primary and secondary plankton production and top predators. Since krill abundance is a crucial factor in Antarctic ecosystem functioning, its monitoring supplies vital data. Acoustic surveys are an effective approach to estimating krill abundance. An acoustic survey was conducted in the western Ross Sea in January 2014-10 years after a similar survey by our team - to estimate krill abundance and biomass and monitor oceanographic conditions. Antarctic krill (Euphausia superba) was detected in the northern part of the western Ross Sea and dense swarms of ice krill (Euphausia crystallorophias) were found in its central coastal area. Data analysis revealed an inverse correlation between E. superba density and salinity in the water column, whereas a positive correlation was found between E. crystallorophias abundance and fluorescence; the latter relationship was confirmed in thematic maps of E. crystallorophias spatial distribution and fluorescence. Comparison of 2004 and 2014 biomass data showed a much greater abundance of both species in the more recent survey.

  12. Acoustic monitoring in the Ross Sea, Antarctica, using hydrophone of the Ocean Bottom Seismometer

    NASA Astrophysics Data System (ADS)

    Yun, Sukyoung; Lee, Won Sang; Kuk Hong, Jong; Yoo, Hyun Jae; Park, Yongcheol; Schmidt-Aursch, Mechita; Geissler, Wolfram H.

    2016-04-01

    Although a number of active source seismic experiments have been conducted over the last few decades to investigate the crustal structure in the Ross Sea, Antarctica, long-term observation to monitor underwater tectonic activities and changes in the cryospheric environment still remains challenging due to existence of sea ice in the study region. Korea Polar Research Institute has accomplished successful deployment of ocean bottom seismometers (OBS) in the Ross Sea collaborating with Alfred Wegener Institute during the period of 2011-2012 and 2014 by Korean icebreaker RV Araon. The OBS system manufactured by K.U.M. contains a hydrophone sensor that allow us to monitor underwater acoustics generated by tectonic and ice-related events. We present spectrograms of the continuous hydroacoustic data and various types of signals, e.g. seismic T-waves, iceequakes, and tremors. There are periodic and harmonic tremors that might be related with tidal modulation, and the seasonal variation of the background noise seems to be related with sea ice concentration.

  13. Inland diatoms from the McMurdo Dry Valleys and James Ross Island, Antarctica

    USGS Publications Warehouse

    Esposito, R.M.M.; Spaulding, S.A.; McKnight, Diane M.; Van De Vijver, B.; Kopalova, K.; Lubinski, D.; Hall, B.; Whittaker, T.

    2008-01-01

    Diatom taxa present in the inland streams and lakes of the McMurdo Dry Valleys and James Ross Island, Antarctica, are presented in this paper. A total of nine taxa are illustrated, with descriptions of four new species (Luticola austroatlantica sp. nov., Luticola dolia sp. nov., Luticola laeta sp. nov., Muelleria supra sp. nov.). In the perennially ice-covered lakes of the McMurdo Dry Valleys, diatoms are confined to benthic mats within the photic zone. In streams, diatoms are attached to benthic surfaces and within the microbial mat matrix. One species, L. austroatlantica, is found on James Ross Island, of the southern Atlantic archipelago, and the McMurdo Dry Valleys. The McMurdo Dry Valley populations are at the lower range of the size spectrum for the species. Streams flow for 6-10 weeks during the austral summer, when temperatures and solar radiation allow glacial ice to melt. The diatom flora of the region is characterized by species assemblages favored under harsh conditions, with naviculoid taxa as the dominant group and several major diatom groups conspicuously absent. ?? 2008 NRC.

  14. Interactive effects of iron, irradiance and CO 2 on Ross Sea phytoplankton

    NASA Astrophysics Data System (ADS)

    Feng, Y.; Hare, C. E.; Rose, J. M.; Handy, S. M.; Ditullio, G. R.; Lee, P. A.; Smith, W. O., Jr.; Peloquin, J.; Tozzi, S.; Sun, J.; Zhang, Y.; Dunbar, R. B.; Long, M. C.; Sohst, B.; Lohan, M.; Hutchins, D. A.

    2010-03-01

    We conducted a factorial shipboard continuous culture experiment to examine the interactive effects of altered iron, irradiance and CO 2 on the summer phytoplankton community of the Ross Sea, Antarctica. After 18 days of continuous incubation, iron enrichment increased phytoplankton biomass, nutrient drawdown, diatom and Phaeocystis abundance, and some photosynthetic parameters. High irradiance significantly increased the number of Phaeocystis antarctica colonies, as well as P. antarctica abundance relative to diatoms. Iron and light had significant interactive effects on diatom and P. antarctica pigment concentrations, P. antarctica colony abundance, and Si:N, Si:C, and N:P ratios. The major influence of high CO 2 was on diatom community structure, by favoring the large centric diatom Chaetoceros lineola over the small pennate species Cylindrotheca closterium. The ratio of centric to pennate diatoms was significantly responsive to changes in all three variables individually, and to all of their possible two- and three-way combinations. These results suggest that shifts in light, iron, and CO 2 and their mutual interactions all play a role in controlling present day Ross Sea plankton community structure, and need to be considered when predicting the possible future responses of biology and biogeochemistry in this region.

  15. Ross ice shelf cavity circulation, residence time, and melting: Results from a model of oceanic chlorofluorocarbons

    NASA Astrophysics Data System (ADS)

    Reddy, Tasha E.; Holland, David M.; Arrigo, Kevin R.

    2010-04-01

    Despite their harmful effects in the upper atmosphere, anthropogenic chlorofluorocarbons dissolved in seawater are extremely useful for studying ocean circulation and ventilation, particularly in remote locations. Because they behave as a passive tracer in seawater, and their atmospheric concentrations are well-mixed, well-known, and have changed over time, they are ideal for gaining insight into the oceanographic characteristics of the isolated cavities found under Antarctic ice shelves, where direct observations are difficult to obtain. Here we present results from a modeling study of air-sea chlorofluorocarbon exchange and ocean circulation in the Ross Sea, Antarctica. We compare our model estimates of oceanic CFC-12 concentrations along an ice shelf edge transect to field data collected during three cruises spanning 16 yr. Our model produces chlorofluorocarbon concentrations that are quite similar to those measured in the field, both in magnitude and distribution, showing high values near the surface, decreasing with depth, and increasing over time. After validating modeled circulation and air-sea gas exchange through comparison of modeled temperature, salinity, and chlorofluorocarbons with field data, we estimate that the residence time of water in the Ross Ice Shelf cavity is approximately 2.2 yr and that basal melt rates for the ice shelf average 10 cm yr -1. The model predicts a seasonal signature to basal melting, with highest melt rates in the spring and also the fall.

  16. Astronaut Ross Approaches Assembly Concept for Construction of Erectable Space Structure (ACCESS)

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The crew assigned to the STS-61B mission included Bryan D. O'Conner, pilot; Brewster H. Shaw, commander; Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission's primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Australia); and SATCOM KU-2 (RCA Americom). Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, Virginia, and the Marshall Space Flight Center (MSFC), EASE and ACCESS were developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). In this STS-61B onboard photo, astronaut Ross, perched on the Manipulator Foot Restraint (MFR) approaches the erected ACCESS. The primary objective of these experiments was to test the structural assembly concepts for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction.

  17. Competition among penguins and cetaceans reveals trophic cascades in the western Ross Sea, Antarctica.

    PubMed

    Ainley, David G; Ballard, Grant; Dugger, Katie M

    2006-08-01

    An apparent trophic cascade that appears during summer in the western Ross Sea, Antarctica, explains why the Antarctic silverfish (Pleuragramma antarcticum) there becomes cannibalistic; its principal prey, crystal krill (Euphausia crystallorophias) becomes scarce; and the diatom community is minimally grazed compared to adjacent areas. The krill is the major grazer of diatoms. On the basis of fieldwork at Ross Island, we suggest that the cascade results from foraging by unusually numerous Adélie Penguins (Pygoscelis adeliae), minke whales (Balaenoptera bonaerensis), and fish-eating killer whales (Orcinus orca). These species and other top predators apparently deplete the krill and silverfish. In drawing our conclusions, we were aided by two "natural experiments." In one "experiment," large, grounded icebergs altered the seasonal pattern of change in regional sea-ice cover, but not the seasonal change in penguin diet and foraging behavior that was also detected during the pre-iceberg era. In the other "experiment," a short-term polynya (opening in the ice) brought penguins and whales together in a confined area, this time altering both penguin diet and foraging behavior. We conclude that the foraging of penguins and whales, and not a formerly hypothesized seasonal decrease in sea-ice cover, explains (1) the annual switch in the penguins' prey from krill to silverfish, (2) the subsequent lengthening of penguin foraging trips, and (3) a marked decline of cetaceans in the area later in the season. Reduction in the middle-trophic-level prey is expressed in the relaxed grazing pressure on phytoplankton.

  18. Nursing the dying: implications of Kübler-Ross' staging theory.

    PubMed

    Germain, C P

    1980-01-01

    Society's failure to value the work of nurses, the professionals most frequently involved in the care of the dying, is attributed to a cultural definition of nursing as a second-class occupation and the public's need to deny the realities of the suffering and indignities often associated with the process of dying. Efforts within the field of nursing to improve the care of the dying, by shifting emphasis from a narrow physical focus to a more holistic patient and family focus, preceded the past decade's contributions of Elisabeth Kübler-Ross. Although her staging theory has been cited as having limitations in development and in interpretation, Kübler-Ross' influence towards increasing awareness of the needs of the dying and others experiencing major losses has been substantial as evidenced by many references to staging theory in nursing literature, by a marked increase in attention to holistic care of the dying in the basic and continuing education programs of nursing, and by specialty role development in nursing care of the dying. This decade has also witnessed the major growth of professionalism in nursing, including strides towards professional autonomy. Conflict with the traditional pattern of medical dominance and bureacratic constraints in institutions is inevitable, especially when the medical goal of cure is not attainable. Change to an interdisciplinary model of care is viewed as essential for optimal care of the dying and their families.

  19. Glider observations of the biological response to Modified Circumpolar Deep Water Variability in the Ross Sea

    NASA Astrophysics Data System (ADS)

    O'Connell, D.; Kaufman, D.; Friedrichs, M. A.; Smith, W.

    2011-12-01

    The Ross Sea is the most productive area within the Southern Ocean, and is believed to play a significant role in the global marine carbon cycle. This region is also characterized by strong spatial and temporal variability in both physical and biogeochemical conditions; however this variability occurs on spatial and temporal scales that are difficult to resolve with traditional data sources. In order to better understand this variability, two gliders were deployed in the Ross Sea in late November 2010 during the early stages of the summer plankton bloom. Together, the two gliders made over 1500 dives and collected data (salinity, temperature, fluorescence and oxygen) throughout the water column for roughly two months. The data from these gliders were used to identify the presence of the relatively high-nutrient Modified Circumpolar Deep Water (MCDW), which has been hypothesized to be a significant factor affecting the spatial and temporal extent of the summer plankton blooms. Preliminary data analyses indicate a positive correlation between areas of MCDW and high chlorophyll concentrations. The glider data were also compared to contemporaneous cruise data and satellite data and were found to fit well with these other data, yet were better able to resolve the high temporal and spatial variability of this region. Specifically, the lower resolution of the cruise data, as compared to the glider data, made it difficult to resolve the correlation of MCDW to high chlorophyll from the cruise data alone.

  20. Increase of the Antarctic Sea Ice Extent is highly significant only in the Ross Sea

    PubMed Central

    Yuan, Naiming; Ding, Minghu; Ludescher, Josef; Bunde, Armin

    2017-01-01

    In the context of global warming, the question of why Antarctic sea ice extent (SIE) has increased is one of the most fundamental unsolved mysteries. Although many mechanisms have been proposed, it is still unclear whether the increasing trend is anthropogenically originated or only caused by internal natural variability. In this study, we employ a new method where the underlying natural persistence in the Antarctic SIE can be correctly accounted for. We find that the Antarctic SIE is not simply short-term persistent as assumed in the standard significance analysis, but actually characterized by a combination of both short- and long-term persistence. By generating surrogate data with the same persistence properties, the SIE trends over Antarctica (as well as five sub-regions) are evaluated using Monte-Carlo simulations. It is found that the SIE trends over most sub-regions of Antarctica are not statistically significant. Only the SIE over Ross Sea has experienced a highly significant increasing trend (p = 0.008) which cannot be explained by natural variability. Influenced by the positive SIE trend over Ross Sea, the SIE over the entire Antarctica also increased over the past decades, but the trend is only at the edge of being significant (p = 0.034). PMID:28117453

  1. Ross Sea Mollusca from the Latitudinal Gradient Program: R/V Italica 2004 Rauschert dredge samples

    PubMed Central

    Ghiglione, Claudio; Alvaro, Maria Chiara; Griffiths, Huw J.; Linse, Katrin; Schiaparelli, Stefano

    2013-01-01

    Abstract Information regarding the molluscs in this dataset is based on the Rauschert dredge samples collected during the Latitudinal Gradient Program (LGP) on board the R/V “Italica” in the Ross Sea (Antarctica) in the austral summer 2004. A total of 18 epibenthic dredge deployments/samplings have been performed at four different locations at depths ranging from 84 to 515m by using a Rauschert dredge with a mesh size of 500μm. In total 8,359 specimens have been collected belonging to a total of 161 species. Considering this dataset in terms of occurrences, it corresponds to 505 discrete distributional records (incidence data). Of these, in order of abundance, 5,965 specimens were Gastropoda (accounting for 113 species), 1,323 were Bivalvia (accounting for 36 species), 949 were Aplacophora (accounting for 7 species), 74 specimens were Scaphopoda (3 species), 38 were Monoplacophora (1 species) and, finally, 10 specimens were Polyplacophora (1 species). This data set represents the first large-scale survey of benthic micro-molluscs for the area and provides important information about the distribution of several species, which have been seldom or never recorded before in the Ross Sea. All vouchers are permanently stored at the Italian National Antarctic Museum (MNA), Section of Genoa, enabling future comparison and crosschecking. This material is also currently under study, from a molecular point of view, by the barcoding project “BAMBi” (PNRA 2010/A1.10). PMID:24146597

  2. Ross-Kabbani Operation in an Infant with Mitral Valve Dysplasia

    PubMed Central

    Napoleone, Carlo Pace; Oppido, Guido; Angeli, Emanuela; Giardini, Alessandro; Gargiulo, Gaetano

    2009-01-01

    Background. Mitral valve replacement can be very difficult to obtain in infants because the valve annulus diameter can be smaller than the available prosthesis. Case Report. We describe the case of a 2-month-old female weighing 3.5 kg affected by mitral valve dysplasia leading to severe valve stenosis. Despite full medication, the clinical conditions were critical and surgery was undertaken. The mitral valve was unsuitable for repair and the orifice of mitral anulus was 12 mm, too small for a mechanical prosthesis. Therefore, a Ross-Kabbani operation was undertaken, replacing the mitral valve with the pulmonary autograft and reconstructing the right ventricular outflow tract with an etherograft. Results. The postoperative course was uneventful and the clinical conditions are good at 4-month follow-up. Conclusion. The Ross-Kabbani operation can be an interesting alternative to mitral valve replacement in infants when valve repair is not achievable and there is little space for an intra-annular mechanical prosthesis implant. PMID:20049318

  3. The Eocene-Oligocene Boundary in the Ross Sea (Antarctica), Based on Downhole Measurements

    NASA Astrophysics Data System (ADS)

    Buecker, C.; Jarrard, R.; Ehrmann, W.; Niessen, F.; Wonik, T.

    2001-12-01

    Drillholes CRP-1 to 3 of the Cape Roberts Project in the Northern McMurdo Sound (Ross Sea, Antarctica) targeted the western margin of the Victoria Land Basin to investigate Neogene to Paleogene climatic and tectonic history. Drilling on fast sea ice resulted in coring a stratigraphic succession with a composite thickness of 1500 m and an age range of 17 - 34 Ma. Well logging of CRP-3 has provided a complete and comprehensive dataset of in situ geophysical measurements down to 939 meters below sea floor (mbsf). By cluster analysis of the downhole logging data, it was possible to divide the borehole into three main sections. The upper section down to 230 mbsf is dominated by mudstones with clearly different physical properties from the mudstones occurring below this depth. Beneath 230 mbsf sandstones are dominating the lithology. Two types of sandstones could be characterized, with the lower sandstone being dominant below 630 mbsf down to a brecciated shear zone at 790 mbsf. These two types of sandstones, which are differentiated mainly by their magnetic properties, can be correlated to the detrital mode provenance analysis. The boundary marks the Eocene/Oligocene boundary. Comparison of these results with the seismic stratigraphy shows that the major change in sediment source from Victoria to Taylor Group is not seen by seismic sequence analysis. This finding will have consequences for the entire Ross Sea seismic stratigraphy.

  4. Downhole measurements and their use for stratigraphic correlations in the Ross Sea (Antarctica)

    NASA Astrophysics Data System (ADS)

    Bücker, C.; Jarrard, R.; Ehrmann, W.; Niessen, F.; Wonik, T.

    2003-04-01

    Drillholes CRP-1 to 3 of the Cape Roberts Project in the Northern McMurdo Sound (Ross Sea, Antarctica) targeted the western margin of the Victoria Land Basin to investigate Neogene to Paleogene climatic and tectonic history. Drilling on fast sea ice resulted in coring a stratigraphic succession with a composite thickness of 1500 m and an age range of 17 - 34 Ma. Well logging of CRP-3 has provided a complete and comprehensive dataset of in situ geophysical measurements down to 939 meters below sea floor (mbsf). By cluster analysis of the downhole logging data, it was possible to divide the borehole into three main sections. The upper section down to 230 mbsf is dominated by mudstones with clearly different physical properties from the mudstones occurring below this depth. Beneath 230 mbsf sandstones are dominating the lithology. Two types of sandstones could be characterized, with the lower sandstone being dominant below 630 mbsf down to a brecciated shear zone at 790 mbsf. These two types of sandstones, which are differentiated mainly by their magnetic properties, can be correlated to the detrital mode provenance analysis. The boundary marks the Eocene/Oligocene boundary. Comparison of these results with the seismic stratigraphy shows that the major change in sediment source from Victoria to Taylor Group is not seen by seismic sequence analysis. This finding will have consequences for the entire Ross Sea seismic stratigraphy.

  5. Acute plateletpheresis and aprotinin reduces the need for blood transfusion following Ross operation.

    PubMed

    Al-Rashidi, Faleh; Bhat, Misha; Pierre, Leif; Koul, Bansi

    2007-10-01

    The effect of acute intraoperative plateletpheresis (25% platelet yield) in combination with intraoperative low-dose aprotinin (2 million units) on blood conservation was investigated in 18 young adult patients undergoing elective Ross operation. The results were compared with a group of 19 similar patients without plateletpheresis (control group). The hematological and coagulation parameters at admission and discharge were statistically similar in both groups. The total blood product transfusion requirements were significantly reduced in the plateletpheresis group compared with the control group (3.2 units and 5.1 units, respectively, P=0.036). The total blood donor exposure was also reduced significantly in the plateletpheresis group compared with the control group (3.2 and 6.9 donors/patient, respectively, P<0.001). The direct costs for the hospital for the plateletpheresis procedure, including costs for all blood products, were similar to those for blood products alone in the control group. In summary, acute plateletpheresis in combination with low-dose aprotinin significantly reduces the blood product transfusions and blood donor exposures following the Ross operation; the treatment is cost-effective.

  6. Bacterivory by a Summer Assemblage of Nanoplankton in the Ross Sea, Antarctica: Mixotrophic Versus Heterotrophic Protists

    NASA Astrophysics Data System (ADS)

    Sanders, R. W.; Gast, R. J.

    2016-02-01

    Many protists traditionally described as phototrophic have recently been shown to have retained the primitive trait of phagotrophy, and thus function as mixotrophs. Mixotrophic nanoflagellates were identified in every sample examined from a summer cruise in the Ross Sea, Antarctica, where they often were more abundant than heterotrophic nanoflagellates that have previously been considered the major bacterivores in marine waters. Mixotrophs, identified by uptake of fluorescent tracers, comprised similar proportions (9-75%) of the total bacterivorous flagellates in summer as were previously determined for an earlier spring cruise in the Ross Sea. Protist diversity also was linked to functional bacterivores using a culture-independent method in which BrdU-labeled DNA of bacterial prey was incorporated into the DNA of eukaryotic grazers. Immunoprecipitation of the BrdU-labeld DNA was followed by high-throughput sequencing to identify a diverse group of bacterivores, including numerous uncultured eukaryotes. However, its utility for identification of mixotrophs was limited by the availability of sequences from known mixotrophs.

  7. Occurrence and metabolic activity of organisms under the ross ice shelf, antarctica, at station j9.

    PubMed

    Azam, F; Beers, J R; Campbell, L; Carlucci, A F; Holm-Hansen, O; Reid, F M; Karl, D M

    1979-02-02

    Seawater samples below the Ross Ice Shelf were collected through an access hole at J9, approximately 400 kilometers from the Ross Sea, Antarctica. The 237-meter water column had sparse populations of bacteria (8.7 x 10(6) to 1.2 x 10(7) per liter), microplankters (10(2) to 10(3) per cubic meter), and zooplankters (10 to 20 per cubic meter) at the depths studied. Microbial biomass estimates from cellular adenosine 5'-triphosphate measurements were very low (10 to 150 nanograms of carbon per liter), comparable with values for the abyssal ocean. Microbial populations assimilated tritiated D-glucose, thymidine, uridine, and adenosine triphosphate at extremely low rates, comparable with deep-sea heterotrophic populations. Sediment samples had 10(7) to 10(8) bacteria per gram (dry weight), which were metabolically active as shown by respiration of uniformly labeled D-[(14)C]glucose. From this study it cannot be determined whether these organisms in the water column and sediments constitute a functioning food web.

  8. Recent changes in the flow of the Ross Ice Shelf, West Antarctica

    NASA Astrophysics Data System (ADS)

    Hulbe, Christina L.; Scambos, Ted A.; Lee, Choon-Ki; Bohlander, Jennifer; Haran, Terry

    2013-08-01

    Comparison of surface velocities measured during the Ross Ice Shelf Geophysical and Glaciological Survey (RIGGS, 1973 to 1978) and velocities measured via feature tracking between two Moderate-resolution Imaging Spectroradiometer (MODIS) mosaics (compiled from 2003/4 and 2008/9 images) reveals widespread slowing and minor areas of acceleration in the Ross Ice Shelf (RIS) over the approximately 30 year interval. The largest changes (-13 ma) occur near the Whillans and Mercer Ice Streams grounding line in the southernmost part of the ice shelf. Speed has increased over the interval (up to 5 ma) between the MacAyeal Ice Stream grounding line and the shelf front, and along the eastern shelf front. Changes in ice thickness computed using ICESat laser altimetry are used together with a well-tested model of the ice shelf to investigate underlying causes of change in the flow of the ice shelf over time. The observed transients represent a combination of recent forcings and ongoing response to ice stream discharge variations over the past millennium. While evidence of older events may be present, the modern signal is dominated by shorter time scale events, including the stagnation of Kamb Ice Stream about 160 years ago, recent changes in basal drag on the Whillans Ice Stream ice plain and, perhaps, iceberg calving. Details in embayment geometry, for example the shallow sea floor below Crary Ice Rise, modulate the spatial pattern of ice shelf response to boundary condition perturbations.

  9. Enhanced cross-shelf exchange by tides in the western Ross Sea

    NASA Astrophysics Data System (ADS)

    Wang, Q.; Danilov, S.; Hellmer, H.; Sidorenko, D.; Schröter, J.; Jung, T.

    2013-11-01

    The western Ross Sea is one of the key sites for cross-shelf water exchange around Antarctica. The mechanism through which tides affect the cross-shelf exchange in the northwestern Ross Sea is investigated using numerical simulations. Tides are found to increase the high-salinity shelf water (HSSW) outflow through the impact on the warm water intrusion of open ocean origin. The residual tidal currents are onshore along the Modified Circumpolar Deep Water pathway and therefore enhance its intrusion. Lighter ambient water adjacent to the HSSW increases the cross-flow density gradient, thus strengthening the HSSW export. At the same time, the onshore residual current and increased dilution of the HSSW have the potential to reduce the export rate. Owing to the existence of opposite tidal effects, the strongest HSSW export happens at the intermediate tidal forcing strength. The amplification of tides on cross-shelf exchange indicates that the relevant dynamical processes should be simulated or parameterized in climate models in order to adequately predict the ocean.

  10. Estimating the benthic efflux of dissolved iron on the Ross Sea continental shelf

    NASA Astrophysics Data System (ADS)

    Marsay, C. M.; Sedwick, P. N.; Dinniman, M. S.; Barrett, P. M.; Mack, S. L.; McGillicuddy, D. J.

    2014-11-01

    Continental margin sediments provide a potentially large but poorly constrained source of dissolved iron (dFe) to the upper ocean. The Ross Sea continental shelf is one region where this benthic supply is thought to play a key role in regulating the magnitude of seasonal primary production. Here we present data collected during austral summer 2012 that reveal contrasting low surface (0.08 ± 0.07 nM) and elevated near-seafloor (0.74 ± 0.47 nM) dFe concentrations. Combining these observations with results from a high-resolution physical circulation model, we estimate dFe efflux of 5.8 × 107 mol yr-1 from the deeper portions (>400 m) of the Ross Sea continental shelf; more than sufficient to account for the inferred "winter reserve" dFe inventory at the onset of the growing season. In addition, elevated dFe concentrations observed over shallower bathymetry suggest that such features provide additional inputs of dFe to the euphotic zone throughout the year.

  11. Ross Sea Mollusca from the Latitudinal Gradient Program: R/V Italica 2004 Rauschert dredge samples.

    PubMed

    Ghiglione, Claudio; Alvaro, Maria Chiara; Griffiths, Huw J; Linse, Katrin; Schiaparelli, Stefano

    2013-01-01

    Information regarding the molluscs in this dataset is based on the Rauschert dredge samples collected during the Latitudinal Gradient Program (LGP) on board the R/V "Italica" in the Ross Sea (Antarctica) in the austral summer 2004. A total of 18 epibenthic dredge deployments/samplings have been performed at four different locations at depths ranging from 84 to 515m by using a Rauschert dredge with a mesh size of 500μm. In total 8,359 specimens have been collected belonging to a total of 161 species. Considering this dataset in terms of occurrences, it corresponds to 505 discrete distributional records (incidence data). Of these, in order of abundance, 5,965 specimens were Gastropoda (accounting for 113 species), 1,323 were Bivalvia (accounting for 36 species), 949 were Aplacophora (accounting for 7 species), 74 specimens were Scaphopoda (3 species), 38 were Monoplacophora (1 species) and, finally, 10 specimens were Polyplacophora (1 species). This data set represents the first large-scale survey of benthic micro-molluscs for the area and provides important information about the distribution of several species, which have been seldom or never recorded before in the Ross Sea. All vouchers are permanently stored at the Italian National Antarctic Museum (MNA), Section of Genoa, enabling future comparison and crosschecking. This material is also currently under study, from a molecular point of view, by the barcoding project "BAMBi" (PNRA 2010/A1.10).

  12. New age control on a mid-shelf grounding event in Eastern Basin, Ross Sea

    NASA Astrophysics Data System (ADS)

    Cone, A. N.; Bart, P. J.

    2009-12-01

    It is widely accepted that the West Antarctic Ice Sheet (WAIS) was grounded at the continental shelf edge in the eastern Ross Sea during the Last Glacial Maximum (LGM), but the precise chronology is debated. Post-LGM ice retreat chronologies have been developed using radiocarbon dating, mainly of acid-insoluble organics (AIO). Foraminifer tests yield more accurate radiocarbon dates than AIO because forams are less likely to be contaminated by allochthonous carbon, but unfortunately forams are sparse in Antarctic marine sediment cores. Here we show four consistent radiocarbon dates from forams in cored intervals within the foreset of a mid-continental-shelf grounding-zone wedge in Eastern Basin, Ross Sea. Our new radiocarbon dates reveal that the WAIS was grounded on the mid continental shelf circa 32,000 14C yr B.P., suggesting that retreat from this position began more than 10,000 years prior to the maximum sea level fall and global cooling associated with LGM. The dates contradict previous studies, which concluded that the WAIS was at its maximum shelf edge extent during LGM.

  13. Ice-stream initiation, duration and thinning on James Ross Island, northern Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Glasser, N. F.; Davies, B. J.; Carrivick, J. L.; Rodés, A.; Hambrey, M. J.; Smellie, J. L.; Domack, E.

    2014-02-01

    Predicting the future response of the Antarctic Ice Sheet to climate change requires an understanding of the ice streams that dominate its dynamics. Here we use cosmogenic isotope exposure-age dating (26Al, 10Be and 36Cl) of erratic boulders on ice-free land on James Ross Island, north-eastern Antarctic Peninsula, to define the evolution of Last Glacial Maximum (LGM) ice in the adjacent Prince Gustav Channel. These data include ice-sheet extent, thickness and dynamical behaviour. Prior to ˜18 ka, the LGM Antarctic Peninsula Ice Sheet extended to the continental shelf-edge and transported erratic boulders onto high-elevation mesas on James Ross Island. After ˜18 ka there was a period of rapid ice-sheet surface-lowering, coincident with the initiation of the Prince Gustav Ice Stream. This timing coincided with rapid increases in atmospheric temperature and eustatic sea-level rise around the Antarctic Peninsula. Collectively, these data provide evidence for a transition from a thick, cold-based LGM Antarctic Peninsula Ice Sheet to a thinner, partially warm-based ice sheet during deglaciation.

  14. Changes on the ice plain of Ice Stream B and Ross Ice Shelf

    NASA Technical Reports Server (NTRS)

    Shabtaie, Sion

    1993-01-01

    During the 1970's and 1980's, nearly 200 stations from which accurate, three dimensional position fixes have been obtained from TRANSIT satellites were occupied throughout the Ross Ice Shelf. We have transformed the elevations obtained by satellite altimetry to the same geodetic datum, and then applied a second transformation to reduce the geodetic heights to elevations above mean sea level using the GEM-10C geoidal height. On the IGY Ross Ice Shelf traverse between Oct. 1957 and Feb. 1958, an accurate method of barometric altimetry was used on a loop around the ice shelf that was directly tied to the sea at both ends of the travel route, thus providing absolute elevations. Comparisons of the two sets of data at 32 station pairs on floating ice show a mean difference of 0 +/- 1 m. The elevation data were also compared with theoretical values of elevations for a hydrostatically floating ice shelf. The mean difference between theoretical and measured values of elevations is -2 +/- 1 m.

  15. Changes on the ice plain of Ice Stream B and Ross Ice Shelf

    NASA Technical Reports Server (NTRS)

    Shabtaie, Sion

    1993-01-01

    During the 1970's and 1980's, nearly 200 stations from which accurate, three dimensional position fixes have been obtained from TRANSIT satellites were occupied throughout the Ross Ice Shelf. We have transformed the elevations obtained by satellite altimetry to the same geodetic datum, and then applied a second transformation to reduce the geodetic heights to elevations above mean sea level using the GEM-10C geoidal height. On the IGY Ross Ice Shelf traverse between Oct. 1957 and Feb. 1958, an accurate method of barometric altimetry was used on a loop around the ice shelf that was directly tied to the sea at both ends of the travel route, thus providing absolute elevations. Comparisons of the two sets of data at 32 station pairs on floating ice show a mean difference of 0 +/- 1 m. The elevation data were also compared with theoretical values of elevations for a hydrostatically floating ice shelf. The mean difference between theoretical and measured values of elevations is -2 +/- 1 m.

  16. Iron and temperature interactive effects on diatoms and Phaeocystis antarctica from the Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Zhu, Z.; Xu, K.; Fu, F.; Spackeen, J.; Bronk, D. A.; Hutchins, D. A.

    2016-02-01

    Future temperature and iron availability is predicted to change in the most biologically productive regions of the Southern Ocean, the coastal polynyas of Antarctica. We examined the individual and combined effects of iron addition (+500 nM) and temperature increases (4°C) on Phaeocystis antarctica and several dominant diatom species isolated from McMurdo Sound in the Ross Sea. Iron addition increased growth, carbon fixation, and iron uptake rates, cellular carbon quotas, and cell size of almost all tested species. Temperature increase only affected some species, and in particular had negative effects on P. antarctica growth. Concurrent increases in temperature and iron synergistically stimulated the growth rates of some diatom species, particularly Pseudo-nitzschia subcurvata. The diversity of their responses to iron and temperature may help to explain the current spatial and temporal distributions of diatoms and prymnesiophytes in the Ross Sea. In the future, potential temperature and iron increases may act together to shift the composition of the phytoplankton community in this biologically and biogeochemically important Southern Ocean polynya region.

  17. Increase of the Antarctic Sea Ice Extent is highly significant only in the Ross Sea.

    PubMed

    Yuan, Naiming; Ding, Minghu; Ludescher, Josef; Bunde, Armin

    2017-01-24

    In the context of global warming, the question of why Antarctic sea ice extent (SIE) has increased is one of the most fundamental unsolved mysteries. Although many mechanisms have been proposed, it is still unclear whether the increasing trend is anthropogenically originated or only caused by internal natural variability. In this study, we employ a new method where the underlying natural persistence in the Antarctic SIE can be correctly accounted for. We find that the Antarctic SIE is not simply short-term persistent as assumed in the standard significance analysis, but actually characterized by a combination of both short- and long-term persistence. By generating surrogate data with the same persistence properties, the SIE trends over Antarctica (as well as five sub-regions) are evaluated using Monte-Carlo simulations. It is found that the SIE trends over most sub-regions of Antarctica are not statistically significant. Only the SIE over Ross Sea has experienced a highly significant increasing trend (p = 0.008) which cannot be explained by natural variability. Influenced by the positive SIE trend over Ross Sea, the SIE over the entire Antarctica also increased over the past decades, but the trend is only at the edge of being significant (p = 0.034).

  18. Astronaut Ross Approaches Assembly Concept for Construction of Erectable Space Structure (ACCESS)

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The crew assigned to the STS-61B mission included Bryan D. O'Conner, pilot; Brewster H. Shaw, commander; Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission's primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Australia); and SATCOM KU-2 (RCA Americom). Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, Virginia, and the Marshall Space Flight Center (MSFC), EASE and ACCESS were developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). In this STS-61B onboard photo, astronaut Ross, perched on the Manipulator Foot Restraint (MFR) approaches the erected ACCESS. The primary objective of these experiments was to test the structural assembly concepts for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction.

  19. Determination of embryonic temperature profiles and eggshell water vapor conductance constants in incubating Ross x Ross 708 broiler hatching eggs using temperature transponders.

    PubMed

    Pulikanti, R; Peebles, E D; Zhai, W; Gerard, P D

    2012-01-01

    The comprehensive profiles of the internal and external temperatures of embryonated Ross × Ross 708 broiler hatching eggs during incubation were determined using temperature transponders, and eggshell water vapor conductance (G(H2O)), specific G(H2O) (g(H2O); G(H2O) adjusted to a 100 g set egg weight basis), and G(H2O) constants (K(H2O)) were calculated. On each of 8 replicate tray levels of an incubator, 2 nonembryonated and 4 embryonated eggs were each implanted with a transponder on d 10.5 of incubation for the determination of internal (air cell) temperatures of nonembryonated (T(nem)) and embryonated (T(emb)) eggs, respectively. In addition, 2 water-filled vials, each containing a transponder, were used on each tray level for the determination of the external microenvironment temperatures (T(ext)) of the embryonated and nonembryonated eggs. Between 10.5 and 18 d of incubation, incubator data logger temperatures were determined every 5 min; and incubator dry bulb temperature, T(ext), T(nem), T(emb), and the difference between T(emb) and T(nem) (T) were determined every 12 h. Over the days of incubation, regression coefficients for T(emb) and T were positive, whereas the regression coefficient for T(nem) was negative. There was a significant day of incubation × type of temperature measurement (T(ext), T(nem), and T(emb)) interaction for temperature. Between 13 and 18 d of incubation, mean values of T(emb) readings that were recorded every 12 h were consistently higher than those of T(ext) and T(nem), indicating the importance of air cell transponder implantation for the efficient estimation of broiler embryo temperature. Furthermore, mean values of the percentage of daily incubational egg weight loss, G(H2O), g(H2O), and K(H2O) of the embryonated eggs were 0.54 ± 0.019%, 14.4 ± 0.56 mg of H₂O/d per Torr, 25.0 ± 0.96 mg of H₂O/d per Torr per 100 g, and 5.20 ± 0.205, respectively. The results suggest that transponders may be implanted in the air cells of

  20. Climate change impacts on southern Ross Sea phytoplankton composition, productivity, and export

    NASA Astrophysics Data System (ADS)

    Kaufman, Daniel E.; Friedrichs, Marjorie A. M.; Smith, Walker O.; Hofmann, Eileen E.; Dinniman, Michael S.; Hemmings, John C. P.

    2017-03-01

    The Ross Sea, a highly productive region of the Southern Ocean, is expected to experience warming during the next century along with reduced summer sea ice concentrations and shallower mixed layers. This study investigates how these climatic changes may alter phytoplankton assemblage composition, primary productivity, and export. Glider measurements are used to force a one-dimensional biogeochemical model, which includes diatoms and both solitary and colonial forms of Phaeocystis antarctica. Model performance is evaluated with glider observations, and experiments are conducted using projections of physical drivers for mid-21st and late-21st century. These scenarios reveal a 5% increase in primary productivity by midcentury and 14% by late-century and a proportional increase in carbon export, which remains approximately 18% of primary production. In addition, scenario results indicate diatom biomass increases while P. antarctica biomass decreases in the first half of the 21st century. In the second half of the century, diatom biomass remains relatively constant and P. antarctica biomass increases. Additional scenarios examining the independent contributions of expected future changes (temperature, mixed layer depth, irradiance, and surface iron inputs from melting ice) demonstrate that earlier availability of low light due to reduction of sea ice early in the growing season is the primary driver of productivity increases over the next century; shallower mixed layer depths additionally contribute to changes of assemblage composition and export. This study further demonstrates how glider data can be effectively used to facilitate model development and simulation, and inform interpretation of biogeochemical observations in the context of climate change.Plain Language SummaryUnderstanding how the global ocean responds to climate change requires knowing the natural behavior of individual regions and anticipating how future</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.epa.gov/charlesriver','PESTICIDES'); return false;" href="https://www.epa.gov/charlesriver"><span>Charles <span class="hlt">River</span></span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>Information on the efforts of the US EPA, the Commonwealth of Massachusetts, the municipalities within the Charles <span class="hlt">River</span> Watershed and nongovernmental organizations to improve the water quality of the Charles <span class="hlt">River</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=mens+AND+rea&id=EJ865906','ERIC'); return false;" href="https://eric.ed.gov/?q=mens+AND+rea&id=EJ865906"><span>Men of Good Will: The Religious Education Association, J. Elliot <span class="hlt">Ross</span>, and the National Conference of Jews and Christians</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Nolan, Lucinda A.</p> <p>2009-01-01</p> <p>An impetus of the Religious Education Association (REA) toward becoming an actively intercultural and interreligious agency emerged in the third decade of its existence. This article explores this period through an examination of the involvement of the REA members, Father John Elliot <span class="hlt">Ross</span> and others (1884-1946) in a series of seminars conducted by…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Ross&pg=6&id=EJ865906','ERIC'); return false;" href="http://eric.ed.gov/?q=Ross&pg=6&id=EJ865906"><span>Men of Good Will: The Religious Education Association, J. Elliot <span class="hlt">Ross</span>, and the National Conference of Jews and Christians</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Nolan, Lucinda A.</p> <p>2009-01-01</p> <p>An impetus of the Religious Education Association (REA) toward becoming an actively intercultural and interreligious agency emerged in the third decade of its existence. This article explores this period through an examination of the involvement of the REA members, Father John Elliot <span class="hlt">Ross</span> and others (1884-1946) in a series of seminars conducted by…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=kubler+AND+ross&pg=2&id=EJ480622','ERIC'); return false;" href="http://eric.ed.gov/?q=kubler+AND+ross&pg=2&id=EJ480622"><span>Coping with Dying: Lessons That We Should and Should Not Learn from the Work of Elisabeth Kubler-<span class="hlt">Ross</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Corr, Charles A.</p> <p>1993-01-01</p> <p>Appraises work of Elisabeth Kubler-<span class="hlt">Ross</span> in area of coping with dying. Suggests lessons from that work. Draws broad conclusions about processes involved in coping with dying, argues on behalf of need to develop better theoretical models to explicate what is involved in coping with dying, and suggests requirements for model. (Author/NB)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJS..223...10G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJS..223...10G"><span>A New Analysis of the Two Classical ZZ Ceti White Dwarfs GD 165 and <span class="hlt">Ross</span> 548. II. Seismic Modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Giammichele, N.; Fontaine, G.; Brassard, P.; Charpinet, S.</p> <p>2016-03-01</p> <p>We present the second of a two-part seismic analysis of the bright, hot ZZ Ceti stars GD 165 and <span class="hlt">Ross</span> 548. In this second part, we report the results of detailed searches in parameter space for identifying an optimal model for each star that can account well for the observed periods, while being consistent with the spectroscopic constraints derived in our first paper. We find optimal models for each target that reproduce the six observed periods well within ∼0.3% on the average. We also find that there is a sensitivity on the core composition for <span class="hlt">Ross</span> 548, while there is practically none for GD 165. Our optimal model of <span class="hlt">Ross</span> 548, with its thin envelope, indeed shows weight functions for some confined modes that extend relatively deep into the interior, thus explaining the sensitivity of the period spectrum on the core composition in that star. In contrast, our optimal seismic model of its spectroscopic sibling, GD 165 with its thick envelope, does not trap/confine modes very efficiently, and we find weight functions for all six observed modes that do not extend into the deep core, hence accounting for the lack of sensitivity in that case. Furthermore, we exploit after the fact the observed multiplet structure that we ascribe to rotation. We are able to map the rotation profile in GD 165 (<span class="hlt">Ross</span> 548) over the outermost ∼20% (∼5%) of its radius, and we find that the profile is consistent with solid-body rotation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-03-29/pdf/2013-07332.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-03-29/pdf/2013-07332.pdf"><span>78 FR 19330 - Supplemental Environmental Impact Statement for the <span class="hlt">Ross</span> In-Situ Uranium Recovery Project in...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-03-29</p> <p>... statement; request for comment. SUMMARY: By letter dated January 4, 2011, Strata Energy, Inc., (Strata... Statement (Draft SEIS) for the <span class="hlt">Ross</span> Project. The Draft SEIS is Supplement 5 to NUREG-1910, ``Generic...-415-4737, or by email to pdr.resource@nrc.gov . The Draft SEIS (NUREG-1910, Supplement 5) is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=188123&keyword=Algae+AND+Green&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=78821331&CFTOKEN=55054332','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=188123&keyword=Algae+AND+Green&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=78821331&CFTOKEN=55054332"><span>An examination of the role of colonial Phaeocystis antarctica in the microbial food web of the <span class="hlt">Ross</span> Sea</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The extensive buildup of phytoplankton biomass in the <span class="hlt">Ross</span> Sea conflicts with the view that high rates of herbivory occur in all regions of the Southern Ocean. Nano- and microplanktonic consumers comprise a significant fraction of total plankton biomass; however, the importance o...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-09-16/pdf/2013-22466.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-09-16/pdf/2013-22466.pdf"><span>78 FR 56944 - Strata Energy, Inc. (<span class="hlt">Ross</span> In Situ Recovery Uranium Project); Notice of Atomic Safety and...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-09-16</p> <p>... COMMISSION Strata Energy, Inc. (<span class="hlt">Ross</span> In Situ Recovery Uranium Project); Notice of Atomic Safety and Licensing... (Board) in the above-captioned Strata Energy, Inc. case is hereby reconstituted by appointing Administrative Judge Craig M. White to serve on the Board in place of Administrative Judge Kenneth L. Mossman...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=188123&keyword=method+AND+Research+AND+mixed&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=188123&keyword=method+AND+Research+AND+mixed&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>An examination of the role of colonial Phaeocystis antarctica in the microbial food web of the <span class="hlt">Ross</span> Sea</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The extensive buildup of phytoplankton biomass in the <span class="hlt">Ross</span> Sea conflicts with the view that high rates of herbivory occur in all regions of the Southern Ocean. Nano- and microplanktonic consumers comprise a significant fraction of total plankton biomass; however, the importance o...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Elisabeth+AND+kubler&id=EJ480622','ERIC'); return false;" href="https://eric.ed.gov/?q=Elisabeth+AND+kubler&id=EJ480622"><span>Coping with Dying: Lessons That We Should and Should Not Learn from the Work of Elisabeth Kubler-<span class="hlt">Ross</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Corr, Charles A.</p> <p>1993-01-01</p> <p>Appraises work of Elisabeth Kubler-<span class="hlt">Ross</span> in area of coping with dying. Suggests lessons from that work. Draws broad conclusions about processes involved in coping with dying, argues on behalf of need to develop better theoretical models to explicate what is involved in coping with dying, and suggests requirements for model. (Author/NB)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMOS43B0654T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMOS43B0654T"><span>Impact of the Inverse Barometer Effect on Iceberg Drift in the <span class="hlt">Ross</span> Sea Region, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turnbull, I. D.</p> <p>2006-12-01</p> <p>The Inverse Barometer Effect (IBE) has been observed since the 19^{th} century, first by Sir James Clark <span class="hlt">Ross</span> [Wunsch and Stammer, 1997], as deviations in sea-surface elevation in response to deviations in atmospheric pressure. This effect is expressed by the formula η=-Δ p/(ρo× g), in which η represents the deviation in sea-surface height, Δ p is the deviation in atmospheric pressure, ρo is the ocean water density, and g is the gravitational acceleration. It has been hypothesized that icebergs in the <span class="hlt">Ross</span> Sea region of Antarctica are influenced by the same forces that create the IBE. This hypothesis is supported by studies of icebergs in the <span class="hlt">Ross</span> Sea, Antarctica, where drift data suggest that icebergs are drawn into temporary holding zones, or "iceberg graveyards" situated where the atmosphere tends to have persistent (annual average) low pressure. A physical explanation for the IBE influence on icebergs is that they are able to travel up the sea-surface slope induced by the IBE below atmospheric lows against the gravitational pull because of the pressure gradient force acting on the iceberg's freeboard (the part that is above the waterline). Here, I evaluate the validity of the hypothesized iceberg/IBE relationship using a numerical model of iceberg drift. I have run several experiments to determine how much influence the IBE would have on the movement of an iceberg the shape of B15A, as opposed to the influence wielded by the other major forces acting on the iceberg such as wind and ocean drag, and the Coriolis force. I have for now approached this problem from a theoretical standpoint, building models that employ geostrophic and Ekman approximations to create a wind and ocean current field, and I have placed the iceberg in a variety of pressure fields with one to multiple stationary or moving low pressure systems of varying or constant intensity. If time permits, I shall attempt to evaluate the effects of recorded wind data and use an actual mean</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSMG41A..08R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSMG41A..08R"><span>Response of the marginal marine environment to post-glacial warming in the <span class="hlt">Ross</span> Sea, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Riesselman, C. R.; Parker, R. L.; Gilmer, G. J.; Lee, J. I.; Yoo, K. C.; Lee, M. K.; Subt, C.; Mckay, R. M.; Rosenheim, B. E.; Levy, R. H.; Ohneiser, C.; Dunbar, R. B.</p> <p>2016-02-01</p> <p>The Holocene represents our most recent and accessible window into the forcings and feedbacks that drive global climate, and is characterized by episodes of abrupt change superimposed upon long-term trends. However these intervals of rapid change are not globally synchronous, highlighting the influence of regional climate processes that may operate on societally significant time scales. Around Antarctica, ice core and marine sediment paleoclimate records indicate heterogeneity in the timing and geographic locus of warming associated with deglaciation and Holocene climatic events. Regional variability in the extent of Antarctic warming throughout the Holocene is mirrored in recent observations, where overlapping modern instrumental records reveal dramatic regional differences in the extent and magnitude of polar warming and ice mass balance. In order to understand the processes by which the Antarctic cryosphere responds to - and impacts - a changing climate, it is therefore essential to develop regionally representative records from geographically dispersed locations around the continent and margin. Here, we summarize initial results from a suite of marine sediment cores collected in the Southern Ocean and western <span class="hlt">Ross</span> Sea by the R/V Araon during the 2015 ANA05B expedition. This expedition recovered 35 cores on a latitudinal transect from 69-77° S. In 18 of these, ice retreat is recognized in whole-core measurements of magnetic susceptibility and bulk density, and in a lithologic transition from terrigenous to diatomaceous sediments. To examine the evolution of the marginal marine environment following deglaciation, we focus specifically on cores collected from the Robertson Bay, Moubray Bay, Mawson Glacier, and <span class="hlt">Ross</span> Island regions. In many of these cores, the recovery of seasonally laminated diatom oozes enables us to develop high-resolution snapshot reconstructions of Holocene sea surface conditions, based on diatom micropaleontology and stable isotope</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70021976','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70021976"><span>Transect across the West Antarctic rift system in the <span class="hlt">Ross</span> Sea, Antarctica</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Trey, H.; Cooper, A. K.; Pellis, G.; Della, Vedova B.; Cochrane, G.; Brancolini, Giuliano; Makris, J.</p> <p>1999-01-01</p> <p>In 1994, the ACRUP (Antarctic Crustal Profile) project recorded a 670-km-long geophysical transect across the southern <span class="hlt">Ross</span> Sea to study the velocity and density structure of the crust and uppermost mantle of the West Antarctic rift system. Ray-trace modeling of P- and S-waves recorded on 47 ocean bottom seismograph (OBS) records, with strong seismic arrivals from airgun shots to distances of up to 120 km, show that crustal velocities and geometries vary significantly along the transect. The three major sedimentary basins (early-rift grabens), the Victoria Land Basin, the Central Trough and the Eastern Basin are underlain by highly extended crust and shallow mantle (minimum depth of about 16 km). Beneath the adjacent basement highs, Coulman High and Central High, Moho deepens, and lies at a depth of 21 and 24 km, respectively. Crustal layers have P-wave velocities that range from 5.8 to 7.0 km/s and S-wave velocities from 3.6 to 4.2 km/s. A distinct reflection (PiP) is observed on numerous OBS from an intra-crustal boundary between the upper and lower crust at a depth of about 10 to 12 km. Local zones of high velocities and inferred high densities are observed and modeled in the crust under the axes of the three major sedimentary basins. These zones, which are also marked by positive gravity anomalies, may be places where mafic dikes and sills pervade the crust. We postulate that there has been differential crustal extension across the West Antarctic rift system, with greatest extension beneath the early-rift grabens. The large amount of crustal stretching below the major rift basins may reflect the existence of deep crustal suture zones which initiated in an early stage of the rifting, defined areas of crustal weakness and thereby enhanced stress focussing followed by intense crustal thinning in these areas. The ACRUP data are consistent with the prior concept that most extension and basin down-faulting occurred in the <span class="hlt">Ross</span> Sea during late Mesozoic time, with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011DSRII..58..181O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011DSRII..58..181O"><span>Distribution, abundance and acoustic properties of Antarctic silverfish ( Pleuragramma antarcticum) in the <span class="hlt">Ross</span> Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>O'Driscoll, Richard L.; Macaulay, Gavin J.; Gauthier, Stéphane; Pinkerton, Matt; Hanchet, Stuart</p> <p>2011-03-01</p> <p>Antarctic silverfish ( Pleuragramma antarcticum) is a key link between plankton and the community of top predators in the shelf waters of the <span class="hlt">Ross</span> Sea. In spite of their abundance and important role in Antarctic food chains, very little is known of many ecological and biological aspects of this species. A combined trawl and acoustic survey of silverfish was carried out on the western <span class="hlt">Ross</span> Sea shelf during the New Zealand International Polar Year Census of Antarctic Marine Life research voyage on R.V. Tangaroa in February-March 2008. Multi-frequency acoustic data (12, 38, 70, and 120 kHz) allowed discrimination of silverfish marks from those of krill and other associated species. Mark identification was achieved using targeted midwater trawls. Additional midwater and demersal trawls were carried out at randomly selected locations over the shelf as part of the core biodiversity survey. Silverfish were widely distributed over the <span class="hlt">Ross</span> Sea shelf. Adult silverfish tended to form layers at 100-400 m depth and were sometimes present close to the bottom, where they were frequently caught in demersal trawls shallower than 500 m. A weak layer at about 80 m depth was associated with juvenile silverfish of 50-80 mm standard length. Acoustic backscatter strength from both silverfish and krill marks increased with increasing frequency (i.e., was highest at 120 kHz), which is characteristic of species without an air-filled swimbladder. Acoustic target strengths (TS) for silverfish at 12, 18, 38, 70, and 120 kHz were estimated from anatomically detailed scattering models based on computed tomography (CT) scans of frozen specimens. The relationship between TS and fish length at 38 kHz was sensitive to estimates of density and sound speed contrast within the fish, especially for small specimens (less than 110 mm SL). Our best estimate of the acoustic biomass of silverfish in the study area was 592 000 t (95% confidence interval 326 000-866 000 t). However, the biomass of juvenile</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/misr/gallery/amazon_mouth','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/misr/gallery/amazon_mouth"><span>Amazon <span class="hlt">River</span></span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2013-04-17</p> <p>article title:  Mouth of the Amazon <span class="hlt">River</span>     View ... of the world's mightiest <span class="hlt">rivers</span>. This image of the Amazon's mouth was captured by the Multi-angle Imaging SpectroRadiometer (MISR) ... available at JPL September 8, 2000 - Mouth of the mighty Amazon <span class="hlt">River</span>. project:  MISR ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27300557','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27300557"><span>Dilatation and Dysfunction of the Neo-aortic Root and in 76 Patients After the <span class="hlt">Ross</span> Procedure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zimmermann, Corina A; Weber, Roland; Greutmann, Matthias; Dave, Hitendu; Müller, Christoph; Prêtre, René; Seifert, Burkhardt; Buechel, Emanuela Valsangiacomo; Kretschmar, Oliver; Attenhofer Jost, Christine H</p> <p>2016-08-01</p> <p>Pulmonary autograft replacement (<span class="hlt">Ross</span> procedure) is used as an alternative to prosthetic aortic valve replacement patients with aortic valve disease. There are limited data on incidence and risk factors for dilatation and dysfunction of the neo-aortic after the <span class="hlt">Ross</span> procedure. <span class="hlt">Ross</span> procedure was performed in 100 patients at our institution between 1993 and 2011. In 76 patients, complete follow-up data were available. Their median age at surgery was 16 (0.4-58) years (76 % males; 95 % with congenital aortic valve disease). Median follow-up duration was 5.2 years (0.3-16.0 years). We analyzed their clinical and echocardiographic follow-up to identify possible risk factors for neo-aortic root dilatation and dysfunction. <span class="hlt">Ross</span> procedure included reduction plasty of the native ascending aorta in 25 % of patients. During follow-up, 21 patients (28 %) developed neo-aortic root dilatation, 38 patients (50 %) dilatation oft the native ascending aorta and 7 patients (9 %) at least moderate neo-aortic regurgitation. Univariate risk factors for neo-aortic root dilatation were preoperative aortic regurgitation (p = 0.04), concomitant reduction plasty of the ascending aorta (p = 0.009) and a longer duration of follow-up (p = 0.005). Younger age at surgery was associated with dilatation of the ascending aorta (p = 0.03). Reoperation on the neo-aortic root because of severe dilatation was necessary in 6 patients (8 %), where 2 patients had at least moderate neo-aortic root regurgitation. Neo-aortic root and aortic dilatation are common after the <span class="hlt">Ross</span> procedure. This is often combined with neo-aortic valve dysfunction. Close follow-up of these patients is mandatory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997JGR...10224669S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997JGR...10224669S"><span>Cenozoic geodynamics of the <span class="hlt">Ross</span> Sea region, Antarctica: Crustal extension, intraplate strike-slip faulting, and tectonic inheritance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salvini, Francesco; Brancolini, Giuliano; Busetti, Martina; Storti, Fabrizio; Mazzarini, Francesco; Coren, Franco</p> <p>1997-11-01</p> <p>An integrated study of onshore and offshore geology of the <span class="hlt">Ross</span> Sea region (namely, Victoria Land, north of <span class="hlt">Ross</span> Island, and the <span class="hlt">Ross</span> Sea, Antarctica) has revealed a complex, post-Eocene tectonic framework. Regional NW-SE right-lateral, strike-slip faults are the outstanding feature of this framework and overprint an older Mesozoic extensional event, responsible for formation of N-S basins in the <span class="hlt">Ross</span> Sea. The Cenozoic framework includes kinematic deformation and reactivation along the NW-SE faults, including formation of pull-apart basins, both positive and negative flower structures, and push-up ridges. N-S extensional faults are well developed between NW-SE faults and indicate E-W extension during the Cenozoic, produced by the NW-SE right-lateral strike-slip motion together with regional crustal extension. NNW-SSE compression, induced by the right-lateral, strike-slip kinematics, is indicated by locally inverted NE-SW faults and basins. The evolution, geometry, and location of the Rennick Graben and the Lanterman Range fit well into this model. Variations in the deformational style across the region can be linked to corresponding variations in the bulk crustal rheology, from brittle behavior in the west, to ductile deformation (at subseismic-scale resolution) near the Eastern Basin. A semibrittle region that favors N-S clustering of Cenozoic magmatic activity lies in between. In this region, Cenozoic volcanoes develop at the intersections of the NW-SE and the major N-S faults. The NW-SE faults cut almost continually from the <span class="hlt">Ross</span> Sea to East Antarctica through lithospheric sectors with different rheology and thickness. At least two of the NW-SE faults correspond to older Paleozoic terrane boundaries in northern Victoria Land. The NW-SE faults link in the Southern Ocean with major transform faults related to the plate motions of Australia, New Zealand, and Antarctica.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002Tectp.347..121C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002Tectp.347..121C"><span>Regional compilation and analysis of aeromagnetic anomalies for the Transantarctic Mountains <span class="hlt">Ross</span> Sea sector of the Antarctic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chiappini, M.; Ferraccioli, F.; Bozzo, E.; Damaske, D.</p> <p>2002-03-01</p> <p>Magnetic observations over the area of the Transantarctic Mountains (TAM) and the <span class="hlt">Ross</span> Sea have been compiled into a digital database that furnishes a new regional scale view of the magnetic anomaly crustal field in this key sector of the Antarctic continent. This compilation is a component of the ongoing IAGA/SCAR Antarctic Digital Magnetic Anomaly Project (ADMAP). The aeromagnetic surveys total 115 000 line km, and are distributed across the Victoria Land sector of the TAM, the <span class="hlt">Ross</span> Sea, and Marie Byrd Land. The magnetic campaigns were performed within the framework of the national and international Italian-German-US Antarctic research programs and conducted with differing specifications during nine field seasons from 1971 until 1997. Generally flight line spacing was less than 5 km while survey altitude varied from about 610 to 4000 m above sea level for barometric surveys and was equal to 305 m above topography for the single draped survey. Reprocessing included digitizing the old contour data, improved levelling by means of microlevelling in the frequency domain, and re-reduction to a common reference field based on the DGRF90 model. A multi-frequency grid procedure was then applied to obtain a coherent and merged total intensity magnetic anomaly map. The shaded relief map covers an area of approximately 380 000 km 2. This new compilation provides a regional image of the location and spatial extent of the Cenozoic alkaline magmatism related to the TAM-<span class="hlt">Ross</span> Sea rift, Jurassic tholeiites, and crustal segments of the Early Palaeozoic magmatic arc. A linear, approximately 100-km wide and 600-km long Jurassic rift-like structure is newly identified. Magnetic fabric in the <span class="hlt">Ross</span> Sea rift often matches seismically imaged Cenozoic fault arrays. Major buried onshore pre-rift fault zones, likely inherited from the <span class="hlt">Ross</span> Orogen, are also delineated. These faults may have been reactivated as strike-slip belts that segmented the TAM into various crustal blocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3155878','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3155878"><span>Iron Limitation of a Springtime Bacterial and Phytoplankton Community in the <span class="hlt">Ross</span> Sea: Implications for Vitamin B12 Nutrition</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bertrand, Erin M.; Saito, Mak A.; Lee, Peter A.; Dunbar, Robert B.; Sedwick, Peter N.; DiTullio, Giacomo R.</p> <p>2011-01-01</p> <p>The <span class="hlt">Ross</span> Sea is home to some of the largest phytoplankton blooms in the Southern Ocean. Primary production in this system has previously been shown to be iron limited in the summer and periodically iron and vitamin B12 colimited. In this study, we examined trace metal limitation of biological activity in the <span class="hlt">Ross</span> Sea in the austral spring and considered possible implications for vitamin B12 nutrition. Bottle incubation experiments demonstrated that iron limited phytoplankton growth in the austral spring while B12, cobalt, and zinc did not. This is the first demonstration of iron limitation in a Phaeocystis antarctica-dominated, early season <span class="hlt">Ross</span> Sea phytoplankton community. The lack of B12 limitation in this location is consistent with previous <span class="hlt">Ross</span> Sea studies in the austral summer, wherein vitamin additions did not stimulate P. antarctica growth and B12 was limiting only when bacterial abundance was low. Bottle incubation experiments and a bacterial regrowth experiment also revealed that iron addition directly enhanced bacterial growth. B12 uptake measurements in natural water samples and in an iron fertilized bottle incubation demonstrated that bacteria serve not only as a source for vitamin B12, but also as a significant sink, and that iron additions enhanced B12 uptake rates in phytoplankton but not bacteria. Additionally, vitamin uptake rates did not become saturated upon the addition of up to 95 pM B12. A rapid B12 uptake rate was observed after 13 min, which then decreased to a slower constant uptake rate over the next 52 h. Results from this study highlight the importance of iron availability in limiting early season <span class="hlt">Ross</span> Sea phytoplankton growth and suggest that rates of vitamin B12 production and consumption may be impacted by iron availability. PMID:21886638</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17044377','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17044377"><span>Intermediate-term results of Medtronic freestyle valve for right ventricular outflow tract reconstruction in the <span class="hlt">Ross</span> procedure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bilal, Mehmet S; Aydemir, Numan A; Cine, Nihat; Turan, Tamer; Yildiz, Yahya; Yalcin, Yalim; Celebi, Ahmet</p> <p>2006-09-01</p> <p>The <span class="hlt">Ross</span> procedure has become the first choice for aortic valve replacement in children and young adults at many institutions. Since 1997, a lack of availability of homograft valves in Turkey has prompted the use of alternative substitutes for right ventricular outflow tract (RVOT) reconstruction during the <span class="hlt">Ross</span> procedure. Before April 2005, among 20 patients (age range: 14 months to 45 years) at the present authors' institution, the <span class="hlt">Ross</span> procedure was performed in 14 and a <span class="hlt">Ross</span>-Konno procedure in six. Sixteen patients underwent RVOT repair using alternative methods for homograft valve replacement. Fourteen patients received a Medtronic Freestyle valve and one patient a Medtronic Contegra bovine jugular vein conduit. An autologous RVOT repair was used in one patient. Ten of the Medtronic Freestyle valve patients were aged <16 years. In all patients who received a Medtronic Freestyle valve echocardiographic evaluations were conducted shortly after surgery and during follow up. There was no early mortality. One patient died from pneumonia after six months, and another (asymptomatic) patient died suddenly at 34 months after surgery. Before hospital discharge the mean peak pressure gradient across the Freestyle valve was 12.1 +/- 11.0 mmHg, and this increased to 24.1 +/- 20.0 mmHg after a mean follow up of 51.2 +/- 6.9 months (range: 6 to 101 months) (p <0.002). Mild pulmonary regurgitation was seen in two patients. One asymptomatic adult patient was reoperated on at another center because of a 60-mmHg echocardiographic peak gradient at four years postoperatively. Although long-term follow up is required to explain the durability of the Medtronic Freestyle valve, the present results show that the valve can be used with intermediate-term success in the <span class="hlt">Ross</span> procedure - and even in children as an alternative - if homograft valves are not available.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006GGG.....712011W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006GGG.....712011W"><span>Bedrock platforms within the <span class="hlt">Ross</span> Embayment, West Antarctica: Hypotheses for ice sheet history, wave erosion, Cenozoic extension, and thermal subsidence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilson, Douglas S.; Luyendyk, Bruce P.</p> <p>2006-12-01</p> <p>Ice-penetrating radar (mostly airborne) and marine seismic surveys have revealed plateaus and terraces about 100-350 m below sea level beneath parts of the <span class="hlt">Ross</span> Embayment, including the West Antarctic ice sheet, the <span class="hlt">Ross</span> Ice Shelf, and the eastern <span class="hlt">Ross</span> Sea. These surfaces cover many thousands of square kilometers and are separated by bedrock troughs occupied by the West Antarctic ice streams. Prominent plateaus are under Edward VII Peninsula, Siple Dome, and Roosevelt Island. Marine seismic data and gravity data over the buried plateaus support an interpretation that they were caused by erosion into basement. The flat and level nature of the surfaces that were formed by erosion, are near the same depth over large distances, and fringe the buried rugged bedrock topography of Marie Byrd Land supports an interpretation of marine rather than glacial erosion. Marine seismic reflection profiles over one of the plateau remnants show it as an angular unconformity cut into gently dipping sediments of late Oligocene age, draped with thin, flat-lying sediments, implying that the plateau is early Miocene or younger. The younger limit for plateau erosion follows from the interpretation of the mechanism: erosion must predate permanent ice along the coast associated with the growth of the West Antarctic ice sheet, probably prior to 10 Ma and possibly prior to 14 Ma. The plateaus along the Siple Coast, with depths around 350 meters, do not rebound to close to sea level and wave base for models of removing past and present ice load. This discrepancy can be explained if <span class="hlt">Ross</span> Embayment lithosphere has been cooling and subsiding since significant extension in Eocene to Oligocene time. Our interpretation requires crustal subsidence in the <span class="hlt">Ross</span> Sea, which in turn implies higher bedrock elevations in the past within this region. Higher-standing topography presented an opportunity for the accumulation of local ice sheets and caused sea level fluctuation prior to late Cenozoic time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1414473D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1414473D"><span>Mg/Casea surface temperatures during the Marine Isotope Stage 31 collapse of the <span class="hlt">Ross</span> Ice Shelf</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dunbar, G. B.</p> <p>2012-04-01</p> <p>The recovery of the AND-1b and CRP-1 drill cores from the Southwest <span class="hlt">Ross</span> Sea highlighted the potential instability in of the <span class="hlt">Ross</span> Ice Shelf and the West Antarctic Ice Sheet it buttresses. Both cores recovered a few individuals of the planktonic foraminifera Neogloboquadrina pachyderma from marine isotope stage (MIS) 31. This interval is significant because it marks the youngest occurrence of open ocean diatom sediment at AND-1b, which is now situated under the McMurdo Ice Shelf, indicating a substantial retreat of the <span class="hlt">Ross</span> Ice Shelf occurred during this interglacial. However, sediment deposited after MIS 31 at both sites is represented only by glacial-dominated sediment, suggesting a critical environmental threshold had been crossed enabling the <span class="hlt">Ross</span> Ice Shelf to form and persist. Numerical modeling by Pollard and DeConto (Nature, 2009) suggested that sub-ice oceanic melting is a critical element in the stability of ice shelves and that "WAIS will begin to collapse when nearby ocean temperatures warm by roughly 5°C." Laser ablation ICPMS measurement of the Mg/Ca content of N. pachyderma shows that although there is considerable heterogeneity in the distribution of Mg in their tests the mean Mg/Ca of a sample population appears proportional to calcification temperature. By empirically calibrating Mg/Ca in CRP-1 N. pachyderma against values measured in modern populations collected from <span class="hlt">Ross</span> Sea and Southern Ocean sites with SSTs ranging from 1.2°C to 14°C it is concluded that SST during MIS 31 was warmer than today by 5-9°C, consistent with model projections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21886638','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21886638"><span>Iron limitation of a springtime bacterial and phytoplankton community in the <span class="hlt">ross</span> sea: implications for vitamin b(12) nutrition.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bertrand, Erin M; Saito, Mak A; Lee, Peter A; Dunbar, Robert B; Sedwick, Peter N; Ditullio, Giacomo R</p> <p>2011-01-01</p> <p>The <span class="hlt">Ross</span> Sea is home to some of the largest phytoplankton blooms in the Southern Ocean. Primary production in this system has previously been shown to be iron limited in the summer and periodically iron and vitamin B(12) colimited. In this study, we examined trace metal limitation of biological activity in the <span class="hlt">Ross</span> Sea in the austral spring and considered possible implications for vitamin B(12) nutrition. Bottle incubation experiments demonstrated that iron limited phytoplankton growth in the austral spring while B(12), cobalt, and zinc did not. This is the first demonstration of iron limitation in a Phaeocystis antarctica-dominated, early season <span class="hlt">Ross</span> Sea phytoplankton community. The lack of B(12) limitation in this location is consistent with previous <span class="hlt">Ross</span> Sea studies in the austral summer, wherein vitamin additions did not stimulate P. antarctica growth and B(12) was limiting only when bacterial abundance was low. Bottle incubation experiments and a bacterial regrowth experiment also revealed that iron addition directly enhanced bacterial growth. B(12) uptake measurements in natural water samples and in an iron fertilized bottle incubation demonstrated that bacteria serve not only as a source for vitamin B(12), but also as a significant sink, and that iron additions enhanced B(12) uptake rates in phytoplankton but not bacteria. Additionally, vitamin uptake rates did not become saturated upon the addition of up to 95 pM B(12). A rapid B(12) uptake rate was observed after 13 min, which then decreased to a slower constant uptake rate over the next 52 h. Results from this study highlight the importance of iron availability in limiting early season <span class="hlt">Ross</span> Sea phytoplankton growth and suggest that rates of vitamin B(12) production and consumption may be impacted by iron availability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GBioC..28..423W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GBioC..28..423W"><span>The contribution of aeolian sand and dust to iron fertilization of phytoplankton blooms in southwestern <span class="hlt">Ross</span> Sea, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Winton, V. H. L.; Dunbar, G. B.; Bertler, N. A. N.; Millet, M.-A.; Delmonte, B.; Atkins, C. B.; Chewings, J. M.; Andersson, P.</p> <p>2014-04-01</p> <p>Iron is a limiting micronutrient for primary production in the <span class="hlt">Ross</span> Sea, Antarctica. Recent observations reveal low dissolved Fe (dFe) concentrations in the <span class="hlt">Ross</span> Sea polynya following high initial rates of primary production in summer, after the dFe winter reserve has been consumed. Significant new sources of dFe are therefore required to further sustain phytoplankton blooms. Iron from aeolian sand and dust (ASD) released from melting sea ice is one potential source. To constrain aeolian Fe inputs, we determined ASD mass accumulation rates and the total and soluble Fe content of ASD on sea ice in McMurdo Sound, southwestern (SW) <span class="hlt">Ross</span> Sea. The mean mass accumulation rate was ~1.5 g m-2 yr-1, total Fe content of this ASD was 4 ± 1 wt %, and the percentage of soluble Fe was 11 ± 1%. Our mean estimate of the bulk aeolian dFe flux of 122.1 µmol m-2 yr-1 for the McMurdo Sound region suggests that aeolian Fe can support between 9.0 × 109 and 4.1 × 1011 mol C yr-1 (0.1-4.9 Tg C yr-1) of new primary production. This equates to only ~15% of new primary production in the SW <span class="hlt">Ross</span> Sea, suggesting that aeolian dFe is a minor component of seasonal Fe supply. The very high ASD accumulation on sea ice in McMurdo Sound compared to other regions of Antarctica suggests that our results represent the upper limit of dFe supply to the ocean from this source in the <span class="hlt">Ross</span> Sea.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2007/1047/srp/srp063/of2007-1047srp063.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2007/1047/srp/srp063/of2007-1047srp063.pdf"><span>The Cambrian <span class="hlt">Ross</span> Orogeny in northern Victoria Land (Antarctica) and New Zealand: A synthesis</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Federico, L.; Capponi, G.; Crispini, L.; Bradshaw, J.D.</p> <p>2007-01-01</p> <p>In the Cambrian, the paleo-Pacific margin of the Gondwana supercontinent included East Antarctica, Australia, Tasmania and New Zealand and was affected by themajor <span class="hlt">Ross</span>-Delamerian Orogeny. In Antarctica, evidence suggests that this resulted from oblique subduction and that in northern Victoria Land it was accompanied by the opening and subsequent closure of a back-arc basin. Comparison of the type and timing of sedimentary, magmatic and metamorphic events in areas noted above shows strong similarities between northern Victoria Land and New Zealand. In both regions Middle Cambrian volcanites are interpreted as arc/back-arc assemblages produced by west-directed subduction; sediments interbedded with the volcanites show provenance both from the arc and from the Gondwana margin and therefore place the basin close to the continent. Back-arc closure in the Late Cambrian was likely accomplished through a second subduction system</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/26826','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/26826"><span>Physical, chemical, and biological characteristics of <span class="hlt">Ross</span> Lake, Snohomish County, Washington</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dion, N.P.</p> <p>1979-01-01</p> <p>A study of the physical, chemical, and biological characteristics of <span class="hlt">Ross</span> Lake in 1975 showed that the lake has no well-defined surface-water inflow and that thermal stratification is well established in summer. The water is of a calcium bicarbonate type, which is typical of lakes in western Washington. Biological productivity in the lake was low, as indicated by low to moderate chlorophyll a concentrations, by the general lack of submerged plants on the lake bottom, and by the moderate dissolved-oxygen depletion in the deeper zones during thermal stratification. The productivity probably was limited by the amount of phosphorus available. Increased productivity and the resulting growth of nuisance plants in the lake can be avoided by limiting phosphate inputs to their present or lesser rates. (Woodard-USGS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23969993','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23969993"><span>Increase in penguin populations during the Little Ice Age in the <span class="hlt">Ross</span> Sea, Antarctica.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, Qi-Hou; Sun, Li-Guang; Xie, Zhou-Qing; Emslie, Steven D; Liu, Xiao-Dong</p> <p>2013-01-01</p> <p>Penguins are an important seabird species in Antarctica and are sensitive to climate and environmental changes. Previous studies indicated that penguin populations increased when the climate became warmer and decreased when it became colder in the maritime Antarctic. Here we determined organic markers in a sediment profile collected at Cape Bird, <span class="hlt">Ross</span> Island, high Antarctic, and reconstructed the history of Adélie penguin colonies at this location over the past 700 years. The region transformed from a seal to a penguin habitat when the Little Ice Age (LIA; 1500-1800 AD) began. Penguins then became the dominant species. Penguin populations were the highest during ca. 1490 to 1670 AD, a cold period, which is contrary to previous results in other regions much farther north. Different responses to climate change may occur at low latitudes and high latitudes in the Antarctic, even if for same species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1810770F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1810770F"><span>Changes in sea-ice cover and temperature in the Western <span class="hlt">Ross</span> Sea during the Holocene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fleury, Sophie; Kim, Jung-Hyun; Gal, Jong-Ku; Mezgec, Karin; Belt, Simon; Smik, Lukas; Stenni, Barbara; Melis, Romana; Crosta, Xavier; Shin, Kyung-Hoon</p> <p>2016-04-01</p> <p>Although changes in sea-ice cover contribute to global climatic variations, they are poorly constrained for periods earlier than the last decades. More records are especially required around Antarctica, where the formation of Antarctic Bottom Waters participates to global thermohaline circulation. However, this region provided only a few marine sediment cores spanning the entire Holocene, especially because of generally low sedimentation rates. This study focuses on marine sediment core ANTA99-CJ5 (73°49'S; 175°39'E), located in the open sea ice zone (OSIZ) of the western <span class="hlt">Ross</span> Sea. We analyzed several lipid biomarkers: highly branched isoprenoids (HBIs), sterols, diols and GDGTs. The combination of several biomarkers and the comparison of these results with a diatom record previously published on the same core enabled us to trace past changes in temperatures as well as in sea-ice condition over the last 11,600 years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2007/1047/srp/srp030/of2007-1047srp030.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2007/1047/srp/srp030/of2007-1047srp030.pdf"><span>Geology of the Byrd Glacier Discontinuity (<span class="hlt">Ross</span> Orogen): New survey data from the Britannia Range, Antarctica</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Carosi, R.; Giacomini, F.; Talarico, F.; Stump, E.</p> <p>2007-01-01</p> <p>Field activities in the Britannia Range (Transantarctic Mountains, Antarctica) highlighted new geological features around the so-called Byrd Glacier discontinuity. Recent field surveys revealed the occurrence of significant amounts of medium- to high-grade metamorphic rocks, intruded by abundant coarse-grained porphyritic granitoids. Most of the granitoids are deformed, with foliation parallel to the regional foliation in the metamorphics. Two main episodes of deformation are observed. Tight to isoclinal folds and penetrative axial plane foliation are related to the D1 phase, open folds to the D2. The main foliation (D1) trends nearly E-W in agreement with the trend in the southern portion of the Byrd Glacier. In most outcrops, granitic dykes are folded and stretched by the D2 deformation, which shows similar characteristics with the D2 deformation south of the Byrd Glacier. This suggests the occurrence in the <span class="hlt">Ross</span> orogen of an orogen-normal structure south and north of the Byrd Glacier.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6140721','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6140721"><span>High-paleolatitude late cretaceous paleotemperatures: New data from James <span class="hlt">Ross</span> Island, Antarctica</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pirrie, D. ); Marshall, J.D. )</p> <p>1990-01-01</p> <p>Oxygen-isotope analysis of well-preserved macrofossils from the Santonian-Campanian of James <span class="hlt">Ross</span> Island and the Maastrichtian of Vega Island, Antarctica, indicates that cool high-paleolatitude temperatures prevailed during the Late Cretaceous and suggests that cooling occurred between the Santonian-Campanian and the Maastrichtian. Although more than 50% of the material showed diagenetic alteration, 52 unaltered aragonite and calcite samples were analyzed. Mean {delta}{sup 18}O and calculated paleotemperature values were {minus}0.23{per thousand} and 13.6 C, respectively, for the Santonian-Campanian, and 0.66{per thousand} and 11.7 C, respectively, for the Masstrichtian. In conjunction with recent Late Cretaceous paleoclimatic data from high northern paleolatitudes, these data indicate the presence of cool polar regions with broad climatic zonation during the late Cretaceous. This may have partly controlled faunal distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2007/1047/srp/srp067/of2007-1047srp067.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2007/1047/srp/srp067/of2007-1047srp067.pdf"><span>Influence of submarine morphology on bottom water flow across the western <span class="hlt">Ross</span> Sea continental margin</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Davey, F.J.; Jacobs, S.S.</p> <p>2007-01-01</p> <p>Multibeam sonar bathymetry documents a lack of significant channels crossing outer continental shelf and slope of the western <span class="hlt">Ross</span> Sea. This indicates that movement of bottom water across the shelf break into the deep ocean in this area is mainly by laminar or sheet flow. Subtle, ~20 m deep and up to 1000 m wide channels extend down the continental slope, into tributary drainage patterns on the upper rise, and then major erosional submarine canyons. These down-slope channels may have been formed by episodic pulses of rapid down slope water flow, some recorded on bottom current meters, or by sub-ice melt water erosion from an icesheet grounded at the margin. Narrow, mostly linear furrows on the continental shelf thought to be caused by iceberg scouring are randomly oriented, have widths generally less than 400 m and depths less than 30m, and extend to water depths in excess of 600 m.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-98PC-1757&hterms=Ross&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DRoss','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-98PC-1757&hterms=Ross&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DRoss"><span>STS-88 Mission Specialist Jerry <span class="hlt">Ross</span> in O&C building before launch</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1998-01-01</p> <p>In the Operations and Checkout Building, STS-88 Mission Specialist Jerry L. <span class="hlt">Ross</span> (right) takes part in a complete suit check before launch. Standing with him is Owen Bertrand, chief of the Vehicle Integration Test office at Johnson Space Center. This is Bertrand's last launch before retiring in January. Mission STS-88 is expected to launch at 3:56 a.m. EST with the six-member crew aboard Space Shuttle Endeavour on Dec. 3. Endeavour carries the Unity connecting module, which the crew will be mating with the Russian-built Zarya control module already in orbit. In addition to Unity, two small replacement electronics boxes are on board for possible repairs to Zarya batteries. The mission is expected to last 11 days, 19 hours and 49 minutes, landing at 10:17 p.m. EST on Dec. 14.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-98PC-1497&hterms=Ross&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DRoss','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-98PC-1497&hterms=Ross&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DRoss"><span>STS-88 Mission Specialist <span class="hlt">Ross</span> receives M-113 training during TCDT activities</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1998-01-01</p> <p>STS-88 Mission Specialist Jerry L. <span class="hlt">Ross</span> prepares to operate an M- 113, an armored personnel carrier, as part of emergency egress training under the watchful eye of instructor George Hoggard (left) during Terminal Countdown Demonstration Test (TCDT) activities. The TCDT also provides the crew with simulated countdown exercises and opportunities to inspect their mission payloads in the orbiter's payload bay. Mission STS-88 is targeted for launch on Dec. 3, 1998. It is the first U.S. flight for the assembly of the International Space Station and will carry the Unity connecting module. Others in the STS-88 crew are Mission Commander Robert D. Cabana; Pilot Frederick W. 'Rick' Sturckow; and Mission Specialists Nancy J. Currie, James H. Newman, and Sergei Konstantinovich Krikalev, a Russian cosmonaut.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=STS055-229-030&hterms=Plc&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DPlc','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=STS055-229-030&hterms=Plc&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DPlc"><span>STS-55 MS1/PLC <span class="hlt">Ross</span> monitors Payload Specialist Walter's Anthrorack activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1993-01-01</p> <p>STS-55 German Payload Specialist 1 Ulrich Walter breathes into Rack 9 Anthrorack (AR) (Human Physiology Laboratory) device for Pulmonary Perfusion and Ventilation During Rest and Exercise experiment while working inside the Spacelab Deutsche 2 (SL-D2) science module aboard the Earth-orbiting Columbia, Orbiter Vehicle (OV) 102. Seated on the bicycle ergometer, Walter utilizes the respiratory monitoring system, part of a broad battery of experiments designed to investigate human physiology under microgravity conditions. In the background, Mission Specialist 1 (MS1) and Payload Commander (PLC) Jerry L. <span class="hlt">Ross</span> monitors Walter's activity. Walter represents the German Aerospace Research Establishment (DLR) on the 10-day SL-D2 mission. Visible on the aft end cone are a fire extinguisher and the Crew Telesupport Experiment (CTE) Macintosh portable computer mounted on an adjustable work platform.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2007/1047/srp/srp060/of2007-1047srp060.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2007/1047/srp/srp060/of2007-1047srp060.pdf"><span>High-resolution airborne gravity imaging over James <span class="hlt">Ross</span> Island (West Antarctica)</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Jordan, T.A.; Ferraccioli, F.; Jones, P.C.; Smellie, J.L.; Ghidella, M.; Corr, H. F. J.; Zakrajsek, A.F.</p> <p>2007-01-01</p> <p>James <span class="hlt">Ross</span> Island (JRI) exposes a Miocene-Recent alkaline basaltic volcanic complex that developed in a back-arc, east of the northern Antarctic Peninsula. JRI has been the focus of several geological studies because it provides a window on Neogene magmatic processes and paleoenvironments. However, little is known about its internal structure. New airborne gravity data were collected as part of the first high-resolution aerogeophysical survey flown over the island and reveal a prominent negative Bouguer gravity anomaly over Mt Haddington. This is intriguing as basaltic volcanoes are typically associated with positive Bouguer anomalies, linked to underlying mafic intrusions. The negative Bouguer anomaly may be associated with a hitherto unrecognised low-density sub-surface body, such as a breccia-filled caldera, or a partially molten magma chamber.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12365284','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12365284"><span>[Status of aortic valve reconstruction and <span class="hlt">Ross</span> operation in aortic valve diseases].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sievers, Hans H</p> <p>2002-08-01</p> <p> if these are progressive and combined with aortic insufficiency. <span class="hlt">ROSS</span>-OPERATION: The <span class="hlt">Ross</span>-Operation includes the replacement of the diseased aortic valve with the pulmonary autograft and reconstruction of the right ventricular outflow tract using a homograft. The hemodynamic results are excellent regarding the autograft and also the clinical results with very low thromboembolic risk and acceptable reoperation rate. This method is especially indicated for active young patients, women, who desire children, athletes and patients in general, who like to avoid long-term anticoagulation. In some cases the homograft may develop a dysfunction predominantly a pulmonary stenosis requiring reoperation. In the author's series of 245 <span class="hlt">Ross</span>-operations in 12 years the homograft had to be replaced in 4 cases without letality. Innovative, decellularized homografts with the potential to repopulate with autologeous cells show promising results after 1 year of clinical implantation without signs of antibody development. Probably these tissue-engineered modification may improve the homograft results. The reconstructive techniques of the aortic valve and the <span class="hlt">Ross</span>-operation have a certain risk of reoperation that must be weighed against the advantages of very low hospital and late valve related death, excellent hemodynamics, very low risk of macro- and microembolism as well as bleeding, lack of long-term anticoagulation and unrestricted life-style.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8928198','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8928198"><span>Least likely suicide: the search for my father, <span class="hlt">Ross</span> Lockridge, Jr., author of Raintree County.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lockridge, L</p> <p>1995-01-01</p> <p>"<span class="hlt">Ross</span> Lockridge, Jr. took his own life on March 6th, 1948, two months following publication of his best-selling novel, Raintree County. The thirty-three year old author from Indiana left his wife and four children. His second son, Larry Lockridge, five years old at that time, has undertaken a search for answers to what has been called the greatest single mystery in American letters. Here, he describes the psychology of survivorship as well as the convergence of factors that led to suicide-personality disorder (narcissistic), biological (possibly genetic) predisposition to depression, and cultural factors related to success in the United States. A merging of such interpretive methods may be more productive than a privileging of one over the other."</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43..250M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43..250M"><span>High basal melting forming a channel at the grounding line of <span class="hlt">Ross</span> Ice Shelf, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marsh, Oliver J.; Fricker, Helen A.; Siegfried, Matthew R.; Christianson, Knut; Nicholls, Keith W.; Corr, Hugh F. J.; Catania, Ginny</p> <p>2016-01-01</p> <p>Antarctica's ice shelves are thinning at an increasing rate, affecting their buttressing ability. Channels in the ice shelf base unevenly distribute melting, and their evolution provides insight into changing subglacial and oceanic conditions. Here we used phase-sensitive radar measurements to estimate basal melt rates in a channel beneath the currently stable <span class="hlt">Ross</span> Ice Shelf. Melt rates of 22.2 ± 0.2 m a-1 (>2500% the overall background rate) were observed 1.7 km seaward of Mercer/Whillans Ice Stream grounding line, close to where subglacial water discharge is expected. Laser altimetry shows a corresponding, steadily deepening surface channel. Two relict channels to the north suggest recent subglacial drainage reorganization beneath Whillans Ice Stream approximately coincident with the shutdown of Kamb Ice Stream. This rapid channel formation implies that shifts in subglacial hydrology may impact ice shelf stability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013GeoRL..40.6319K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013GeoRL..40.6319K"><span>Correlated measurements of ozone and particulates in the <span class="hlt">Ross</span> Island region, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kalnajs, Lars E.; Avallone, Linnea M.; Toohey, Darin W.</p> <p>2013-12-01</p> <p>gases, submicron particle size distributions, and bulk filterable halogen content were measured on <span class="hlt">Ross</span> Island, Antarctica, in austral spring 2007. During several surface level, partial ozone depletion events, enhanced submicron particle concentrations, and changes in filterable halogens were observed. These events were characterized by ozone depletions of 5-15 ppbv for durations between 6 and 48 h and associated with threefold-to-fourfold increases in submicron particle mass (PM1.0) over backgrounds of approximately 100 ng m-3. Peak particle number densities were centered on a mode at 500-600 nm in diameter, which is consistent with wintertime sea-salt aerosol size distributions. Filterable chloride also increased during these events, consistent with aerosol being of oceanic origin. Ozone depletion and particle enhancement events were accompanied by increasing temperatures and winds, suggesting that halogen-containing aerosol is generated from windblown snow and brine from the snow pack or sea ice near the ice edge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=STS055-229-030&hterms=plc&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplc','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=STS055-229-030&hterms=plc&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplc"><span>STS-55 MS1/PLC <span class="hlt">Ross</span> monitors Payload Specialist Walter's Anthrorack activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1993-01-01</p> <p>STS-55 German Payload Specialist 1 Ulrich Walter breathes into Rack 9 Anthrorack (AR) (Human Physiology Laboratory) device for Pulmonary Perfusion and Ventilation During Rest and Exercise experiment while working inside the Spacelab Deutsche 2 (SL-D2) science module aboard the Earth-orbiting Columbia, Orbiter Vehicle (OV) 102. Seated on the bicycle ergometer, Walter utilizes the respiratory monitoring system, part of a broad battery of experiments designed to investigate human physiology under microgravity conditions. In the background, Mission Specialist 1 (MS1) and Payload Commander (PLC) Jerry L. <span class="hlt">Ross</span> monitors Walter's activity. Walter represents the German Aerospace Research Establishment (DLR) on the 10-day SL-D2 mission. Visible on the aft end cone are a fire extinguisher and the Crew Telesupport Experiment (CTE) Macintosh portable computer mounted on an adjustable work platform.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=KSC-98PC-1757&hterms=Ross&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DRoss%2BP.%252C','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=KSC-98PC-1757&hterms=Ross&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DRoss%2BP.%252C"><span>STS-88 Mission Specialist Jerry <span class="hlt">Ross</span> in O&C building before launch</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1998-01-01</p> <p>In the Operations and Checkout Building, STS-88 Mission Specialist Jerry L. <span class="hlt">Ross</span> (right) takes part in a complete suit check before launch. Standing with him is Owen Bertrand, chief of the Vehicle Integration Test office at Johnson Space Center. This is Bertrand's last launch before retiring in January. Mission STS-88 is expected to launch at 3:56 a.m. EST with the six-member crew aboard Space Shuttle Endeavour on Dec. 3. Endeavour carries the Unity connecting module, which the crew will be mating with the Russian-built Zarya control module already in orbit. In addition to Unity, two small replacement electronics boxes are on board for possible repairs to Zarya batteries. The mission is expected to last 11 days, 19 hours and 49 minutes, landing at 10:17 p.m. EST on Dec. 14.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.5387G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.5387G"><span>Bottom water export from the western <span class="hlt">Ross</span> Sea, 2007 through 2010</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gordon, Arnold L.; Huber, Bruce A.; Busecke, Julius</p> <p>2015-07-01</p> <p>Bottom water export from the <span class="hlt">Ross</span> Sea, February 2007 to January 2011, exhibits seasonal and interannual variability. Temperature minima coupled to salinity maxima in late austral summer, into the fall, indicate input from High-Salinity Shelf Water (HSSW). Secondary temperature minima lacking the high-salinity trait, characteristic of Low-Salinity Shelf Water (LSSW), appear in the spring. Warmer bottom water similar to modified Circumpolar Deep Water (mCDW) is observed in winter and in early summer. The LSSW and mCDW may be drawn from the Drygalski Basin, as the HSSW pool retreats poleward from the shelf break in response to increased winter polar easterlies allowing these less dense overlying waters to spill into the deep ocean within the benthic layer. Bottom salinity decreased from 2007 to 2011 by 0.007 year-1 significantly higher than regional decadal trends, which we propose is a result of HSSW retreat induced by strengthening polar easterlies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16206560','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16206560"><span>Broiler responsiveness (<span class="hlt">Ross</span> x 708) to diets varying in amino acid density.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kidd, M T; Corzo, A; Hoehler, D; Miller, E R; Dozier, W A</p> <p>2005-09-01</p> <p>Sex-separate male and female broilers (2,592 broilers; <span class="hlt">Ross</span> x 708) were placed in 144 floor pens (12 replications per treatment) and fed diets containing high (H) and moderate (M) amino acid density from 1 to 55 d of age. Diets were formulated using ileal digestible amino acid ratios to Lys. Six dietary treatment combinations (MMMMM, HMMMM, HHMMM, HHHMM, HHHHM, and HHHHH) were implemented in 5 diet phases (1 to 5, 6 to 14, 15 to 35, 36 to 45, and 46 to 55 d of age). Male birds were heavier (P < or = 0.05) and had lower (P < or = 0.05) feed conversion, abdominal fat, and breast yield than female birds. Birds fed H diets in the first 3 phases had optimal (P < or = 0.05) BW and feed conversion (d 35, and 45), but optimal (P < or = 0.05) feed conversion at d 55 warranted H diets in all phases. Breast meat (d 35) and carcass (d 55) relative to BW were highest (P < or = 0.05) in birds fed H diets in the first 3 phases; however, differences in 55 d breast meat yield did not occur. Results indicate that amino acid needs of <span class="hlt">Ross</span> x 708 broilers are most critical from 1 to 35 d of age. Predicted economic margins were advantageous in birds fed H diets resulting in dollar 0.12 and dollar 0.05/bird more income over feed costs at 35 and 55 d, respectively, in comparison with birds fed M diets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.C11C0774H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.C11C0774H"><span>Environment at the Grounding Zone of the Whillans Ice Stream-<span class="hlt">Ross</span> Ice Shelf, West Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hodson, T. O.; Powell, R. D.; Mikucki, J.; Scherer, R. P.; Tulaczyk, S. M.; Coenen, J. J.; Puttkammer, R.; Branecky, C.</p> <p>2015-12-01</p> <p>Grounding zones where grounded ice sheets transition to floating ice shelves, are the primary gateways through which the Antarctic Ice Sheet loses mass to the ocean. In these environments, ice, ocean, meltwater and sediment meet and interact, influencing both the ice sheet and ocean circulation beneath the ice shelf. Here, we report on conditions near the grounding zone of the Whillans Ice Stream, which feeds into the <span class="hlt">Ross</span> Ice Shelf. Cameras and instruments lowered through an access borehole to the ocean cavity beneath the ice shelf found a 10m-thick water column comprising an upper layer of colder ice shelf water formed from mixing between meltwater with the lower layer of warmer higher salinity shelf water. This style of stratification is typical of large ice shelves, but it was uncertain whether it existed so near the grounding zone, where stronger tidal currents and/or strong subglacial stream discharges could mix the water column. Salinity and temperature of the water suggest it formed from sea ice production in the Western <span class="hlt">Ross</span> Sea, with minimal modification beneath the ice shelf. This source region is distinct from waters previously observed at the nearby J-9 borehole, illustrating the importance of the sub-ice shelf bathymetry in steering circulation between the ocean and the grounding zone. Preliminary data suggest an active exchange of heat and nutrients between the grounding zone and the open ocean, despite being separated by 600km. Thus life found near the grounding line is probably not an isolated oasis, but may instead be part of a much broader ecosystem that spans the ice shelf. Although sea ice formation presently maintains water in the sub-ice shelf cavity near the surface freezing point, buffering many larger ice shelves from gradual ocean warming, these findings suggest that even grounding zones of extensive ice shelves may respond quickly to abrupt changes in ocean circulation, such as that observed in the Amundsen Sea.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25051333','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25051333"><span>Diversity and distribution of deep-sea shrimps in the <span class="hlt">Ross</span> Sea region of Antarctica.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Basher, Zeenatul; Bowden, David A; Costello, Mark J</p> <p>2014-01-01</p> <p>Although decapod crustaceans are widespread in the oceans, only Natantia (shrimps) are common in the Antarctic. Because remoteness, depth and ice cover restrict sampling in the South Ocean, species distribution modelling is a useful tool for evaluating distributions. We used physical specimen and towed camera data to describe the diversity and distribution of shrimps in the <span class="hlt">Ross</span> Sea region of Antarctica. Eight shrimp species were recorded: Chorismus antarcticus; Notocrangon antarcticus; Nematocarcinus lanceopes; Dendrobranchiata; Pasiphaea scotiae; Pasiphaea cf. ledoyeri; Petalidium sp., and a new species of Lebbeus. For the two most common species, N. antarcticus and N. lanceopes, we used maximum entropy modelling, based on records of 60 specimens and over 1130 observations across 23 sites in depths from 269 m to 3433 m, to predict distributions in relation to environmental variables. Two independent sets of environmental data layers at 0.05° and 0.5° resolution respectively, showed how spatial resolution affected the model. Chorismus antarcticus and N. antarcticus were found only on the continental shelf and upper slopes, while N. lanceopes, Lebbeus n. sp., Dendrobranchiata, Petalidium sp., Pasiphaea cf. ledoyeri, and Pasiphaea scotiae were found on the slopes, seamounts and abyssal plain. The environmental variables that contributed most to models for N. antarcticus were depth, chlorophyll-a concentration, temperature, and salinity, and for N. lanceopes were depth, ice concentration, seabed slope/rugosity, and temperature. The relative ranking, but not the composition of these variables changed in models using different spatial resolutions, and the predicted extent of suitable habitat was smaller in models using the finer-scale environmental layers. Our modelling indicated that shrimps were widespread throughout the <span class="hlt">Ross</span> Sea region and were thus likely to play important functional role in the ecosystem, and that the spatial resolution of data needs to be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080036090&hterms=sea+boundaries&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsea%2Bboundaries','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080036090&hterms=sea+boundaries&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsea%2Bboundaries"><span><span class="hlt">Ross</span> Sea Polynyas: Response of Ice Concentration Retrievals to Large Areas of Thin Ice</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kwok, R.; Comiso, J. C.; Martin, S.; Drucker, R.</p> <p>2007-01-01</p> <p>For a 3-month period between May and July of 2005, we examine the response of the Advanced Microwave Scanning Radiometer (AMSR-E) Enhanced NASA Team 2 (NT2) and AMSR-E Bootstrap (ABA) ice concentration algorithms to large areas of thin ice of the <span class="hlt">Ross</span> Sea polynyas. Coincident Envisat Synthetic Aperture Radar (SAR) coverage of the region during this period offers a detailed look at the development of the polynyas within several hundred kilometers of the ice front. The high-resolution imagery and derived ice motion fields show bands of polynya ice, covering up to approximately 105 km(sup 2) of the <span class="hlt">Ross</span> Sea, that are associated with wind-forced advection. In this study, ice thickness from AMSR-E 36 GHz polarization information serves as the basis for examination of the response. The quality of the thickness of newly formed sea ice (<10 cm) from AMSR-E is first assessed with thickness estimates derived from ice surface temperatures from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The effect of large areas of thin ice in lowering the ice concentration estimates from both NT2/ABA approaches is clearly demonstrated. Results show relatively robust relationships between retrieved ice concentrations and thin ice thickness estimates that differ between the two algorithms. These relationships define the approximate spatial coincidence of ice concentration and thickness isopleths. Using the 83% (ABA) and 91% (NT2) isopleths as polynya boundaries, we show that the computed coverage compares well with that using the estimated 10-cm thickness contour. The thin ice response characterized here suggests that in regions with polynyas, the retrieval results could be used to provide useful geophysical information, namely thickness and coverage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSHE44D1541D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSHE44D1541D"><span>Comparison of Euphausia superba, Euphausia crystallorophias, Pleuragramma antarcticum and Environmental Distributions in the Western <span class="hlt">Ross</span> Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davis, L.; Hofmann, E. E.; Klinck, J. M., II; Dinniman, M.; Pinones, M. A.</p> <p>2016-02-01</p> <p>Distributions of Antarctic krill (Euphausia superba), crystal krill (Euphausia crystallorophias), and Antarctic silverfish (Pleuragramma antarcticum) were constructed using observations collected in the western <span class="hlt">Ross</span> Sea from 1988-2004. Distributions of mixed layer depth (MLD), water temperature below 200 m (an indicator for Circumpolar Deep Water, CDW), and surface speed were obtained from a <span class="hlt">Ross</span> Sea circulation model; surface chlorophyll and percent sea ice coverage were obtained from satellite observations. The species and environmental distributions were analyzed to determine patterns and correlations. Statistical analyses of the distributions show that the three species are concentrated in specific regions and that their habitats have limited overlap. Antarctic krill are concentrated along the shelf break near Cape Adare and are associated with temperatures >0.5°C and -2°C to -0.75°C, 19-32% sea ice coverage, and high surface flow speeds. Crystal krill are concentrated in Terra Nova Bay in areas with depths of 400-600 m, temperatures < -1.3°, 50% or more sea ice coverage, shallow MLDs (2-36 m), moderate concentrations of chlorophyll (0.44 μg m-3) and low surface speeds (0.08 m s-1). Similarly, Antarctic silverfish are concentrated in Terra Nova Bay and are also found over the continental shelf in areas with depths of 500 m and temperatures of -2°C to -1°C. Additional statistical analyses provide insights into the relative contribution of the different environmental features to producing the distributions of the three species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRC..119.4214A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRC..119.4214A"><span>Ocean variability contributing to basal melt rate near the ice front of <span class="hlt">Ross</span> Ice Shelf, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arzeno, Isabella B.; Beardsley, Robert C.; Limeburner, Richard; Owens, Breck; Padman, Laurie; Springer, Scott R.; Stewart, Craig L.; Williams, Michael J. M.</p> <p>2014-07-01</p> <p>Basal melting of ice shelves is an important, but poorly understood, cause of Antarctic ice sheet mass loss and freshwater production. We use data from two moorings deployed through <span class="hlt">Ross</span> Ice Shelf, ˜6 and ˜16 km south of the ice front east of <span class="hlt">Ross</span> Island, and numerical models to show how the basal melting rate near the ice front depends on sub-ice-shelf ocean variability. The moorings measured water velocity, conductivity, and temperature for ˜2 months starting in late November 2010. About half of the current velocity variance was due to tides, predominantly diurnal components, with the remainder due to subtidal oscillations with periods of a few days. Subtidal variability was dominated by barotropic currents that were large until mid-December and significantly reduced afterward. Subtidal currents were correlated between moorings but uncorrelated with local winds, suggesting the presence of waves or eddies that may be associated with the abrupt change in water column thickness and strong hydrographic gradients at the ice front. Estimated melt rate was ˜1.2 ± 0.5 m a-1 at each site during the deployment period, consistent with measured trends in ice surface elevation from GPS time series. The models predicted similar annual-averaged melt rates with a strong annual cycle related to seasonal provision of warm water to the ice base. These results show that accurately modeling the high spatial and temporal ocean variability close to the ice-shelf front is critical to predicting time-dependent and mean values of meltwater production and ice-shelf thinning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JMS...166...37C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JMS...166...37C"><span>Temporal variability of the Circumpolar Deep Water inflow onto the <span class="hlt">Ross</span> Sea continental shelf</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Castagno, Pasquale; Falco, Pierpaolo; Dinniman, Michael S.; Spezie, Giancarlo; Budillon, Giorgio</p> <p>2017-02-01</p> <p>The intrusion of Circumpolar Deep Water (CDW) is the primary source of heat, salt and nutrients onto Antarctica's continental shelves and plays a major role in the shelf physical and biological processes. Different studies have analyzed the processes responsible for the transport of CDW across the <span class="hlt">Ross</span> Sea shelf break, but until now, there are no continuous observations that investigate the timing of the intrusions. Also, few works have focused on the effect of the tides that control these intrusions. In the <span class="hlt">Ross</span> Sea, the CDW intrudes onto the shelf in several locations, but mostly along the troughs. We use hydrographic observations and a mooring placed on the outer shelf in the middle of the Drygalski Trough in order to characterize the spatial and temporal variability of CDW inflow onto the shelf. Our data span from 2004 to the beginning of 2014. In the Drygalski Trough, the CDW enters as a 150 m thick layer between 250 and 400 m, and moves upward towards the south. At the mooring location, about 50 km from the shelf break, two main CDW cores can be observed: one on the east side of the trough spreading along the west slope of Mawson Bank from about 200 m to the bottom and the other one in the central-west side from 200 m to about 350 m depth. A signature of this lighter and relatively warm water is detected by the instruments on the mooring at bottom of the Drygalski Trough. High frequency periodic CDW intrusion at the bottom of the trough is related to the diurnal and spring/neap tidal cycles. At lower frequency, a seasonal variability of the CDW intrusion is noticed. A strong inflow of CDW is observed every year at the end of December, while the CDW inflow is at its seasonal minimum during the beginning of the austral fall. In addition an interannual variability is also evident. A change of the CDW intrusion before and after 2010 is observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4106907','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4106907"><span>Diversity and Distribution of Deep-Sea Shrimps in the <span class="hlt">Ross</span> Sea Region of Antarctica</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Basher, Zeenatul; Bowden, David A.; Costello, Mark J.</p> <p>2014-01-01</p> <p>Although decapod crustaceans are widespread in the oceans, only Natantia (shrimps) are common in the Antarctic. Because remoteness, depth and ice cover restrict sampling in the South Ocean, species distribution modelling is a useful tool for evaluating distributions. We used physical specimen and towed camera data to describe the diversity and distribution of shrimps in the <span class="hlt">Ross</span> Sea region of Antarctica. Eight shrimp species were recorded: Chorismus antarcticus; Notocrangon antarcticus; Nematocarcinus lanceopes; Dendrobranchiata; Pasiphaea scotiae; Pasiphaea cf. ledoyeri; Petalidium sp., and a new species of Lebbeus. For the two most common species, N. antarcticus and N. lanceopes, we used maximum entropy modelling, based on records of 60 specimens and over 1130 observations across 23 sites in depths from 269 m to 3433 m, to predict distributions in relation to environmental variables. Two independent sets of environmental data layers at 0.05° and 0.5° resolution respectively, showed how spatial resolution affected the model. Chorismus antarcticus and N. antarcticus were found only on the continental shelf and upper slopes, while N. lanceopes, Lebbeus n. sp., Dendrobranchiata, Petalidium sp., Pasiphaea cf. ledoyeri, and Pasiphaea scotiae were found on the slopes, seamounts and abyssal plain. The environmental variables that contributed most to models for N. antarcticus were depth, chlorophyll-a concentration, temperature, and salinity, and for N. lanceopes were depth, ice concentration, seabed slope/rugosity, and temperature. The relative ranking, but not the composition of these variables changed in models using different spatial resolutions, and the predicted extent of suitable habitat was smaller in models using the finer-scale environmental layers. Our modelling indicated that shrimps were widespread throughout the <span class="hlt">Ross</span> Sea region and were thus likely to play important functional role in the ecosystem, and that the spatial resolution of data needs to be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23571338','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23571338"><span>Effect of age on hepatic cytochrome P450 of <span class="hlt">Ross</span> 708 broiler chickens.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, S X</p> <p>2013-05-01</p> <p>Age has significant impact on hepatic cytochrome P450 (CYP450) systems in animals. <span class="hlt">Ross</span> 708 broiler chicken is a breed of chicken with fast growth characteristics. Cytochrome P450 in the livers of <span class="hlt">Ross</span> 708 broiler chicken of different ages has been investigated. The birds were raised under standard husbandry conditions. A certain number of chickens was randomly sampled weekly for liver collection from d 1 to 56 posthatch. The chicken body and liver weights were recorded. The chicken livers were processed for liver microsomes though a multiple-step procedure at low temperature. Total CYP450 content in chicken liver homogenates and liver microsomes was measured using a UV/visible spectroscopic method. The enzymatic activities of CYP450 in the chicken liver microsomes were determined through incubation of CYP450 isoform substrates followed by measurement of formation of their metabolites. The chicken showed an opposite age pattern in hepatic CYP450 content and activities compared with most mammals. The hepatic CYP450 content and activities of chicken at d 1 posthatch were higher than at other ages. The total hepatic CYP450 content in chickens at d 1 posthatch was more than twice the average hepatic value of the chickens at d 7 to 28. This high CYP450 fell quickly in the first week posthatch and slightly rose from d 28 to 56. Hepatic CYP450 activities of CYP1A, 3A, 2C, 2D, and 2H were much higher in the chicken at d 1 posthatch. The differences of these enzymatic activities between d 1 and other ages of chicken were CYP450 isoform dependent. This result suggests that embryonic development of chicken livers has a significant impact on the age profile of hepatic CYP450 content and activities of posthatch chickens.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1510260Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1510260Z"><span>Investigations of the tropospheric halogen chemistry around <span class="hlt">Ross</span> Island, Antarctica, during austral spring 2012</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zielcke, Johannes; Pöhler, Denis; Frieß, Udo; Hay, Tim; Kreher, Karin; Kalnajs, Lars; Platt, Ulrich</p> <p>2013-04-01</p> <p>A unique feature of the polar troposphere is the strong impact of halogen photochemistry, in which reactive halogen species (RHS) are responsible for ozone depletion as well as the oxidation of elemental mercury and dimethyl sulphide. The source, however, as well as release and recycling mechanisms of these halogen species are far from being completely understood, especially the role of chlorine and iodine compounds. Reactive chlorine, bromine and iodine compounds are thought to be released from sea salt particles or produced by the photolysis of halocarbons and I2 emitted by the ocean. Here we present observations of halogen oxides, ozone and nitrogen dioxide conducted for three months during austral spring 2012 on <span class="hlt">Ross</span> Island, Antarctica. Measurements were performed with a suite of remote sensing instruments. An active long-path differential optical absorption spectroscopy (LP-DOAS) system was set up, measuring several species (BrO, O3, NO2, OBrO, IO, OIO, I2, ClO, OClO, CHOCHO, HCHO, HONO) continuously for the whole period, with two light paths over first year sea ice. In addition, a passive MAX-DOAS as well as a new Cavity-Enhanced (CE)-DOAS system were used for mobile halogen oxide measurements on a variety of locations around <span class="hlt">Ross</span> Island (sea ice, shelf ice, snow, coastal, etc.), with top surface layer pH measurements performed at the different measurement sites. First results show highly variable ozone concentrations including partial Ozone Depletion Events (ODEs), as well as concentrations of BrO up to 16ppt and NO2 up to 15ppb. Suprisingly, a high variation of ozone was observed without significant amounts of BrO, indicating already depleted air masses transported to the measurement site and/or NOx chemistry inhibiting halogen radical reactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.8091L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.8091L"><span>Antarctic Ice Sheet dynamics in the <span class="hlt">Ross</span> Sea during the Early to Middle Miocene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Levy, Richard; Harwood, David; Florindo, Fabio; DeConto, Robert; Golledge, Nicholas; Hoffmann, Stefan; Kuhn, Gerhard; McKay, Robert; Naish, Timothy; Pollard, David; Sangiorgi, Francesca; von Eynatten, Hilmar</p> <p>2015-04-01</p> <p>A 1138-meter sediment core (AND-2A) recovered from the Southern McMurdo Sound sector of the <span class="hlt">Ross</span> Sea comprises a near-continuous record of Antarctic climate and ice sheet variability through the Early to early Middle Miocene (20.2 to 14.5 million years ago), including an interval of inferred sustained global warmth known as the Miocene Climatic Optimum (MCO). The record preserves 55 sedimentary sequences that reflect cycles of glacial advance and retreat. A new analysis of proxy environmental data from the AND-2A core, and synthesis with regional geological information, show that the early to middle Miocene Antarctic climate ranged from cold polar conditions, similar to Antarctica during the Holocene, to those that characterise modern sub-polar environments. Four disconformities that punctuate the sedimentary sequence coincide with regionally mapped seismic discontinuities and reflect transient expansion of marine-based ice across the <span class="hlt">Ross</span> Sea. The timing of these major marine-based ice sheet advances correlates with shifts in highly-resolved deep sea isotope records and major drops in eustatic sea-level indicating the global nature of these events. In contrast, three distinct intervals in the core indicate that this high latitude site was periodically influenced by an ice sheet margin that had retreated beyond the coastline. These relatively large-scale changes in climate and ice sheet extent occurred under atmospheric carbon dioxide concentrations that generally varied between 300 to 500 ppm. Therefore, our reconstructions suggest that Antarctica's climate and ice sheets were sensitive to modest changes in greenhouse gas forcing and support previous studies, which indicate that marine-based portions of the WAIS and EAIS can retreat under climatic conditions that were similar to those projected for our future under current levels of atmospheric CO2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.T11A1230H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.T11A1230H"><span>Fault Patterns Within the Eastern Terror Rift, Western <span class="hlt">Ross</span> Sea, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hall, J. M.; Wilson, T. J.; Henrys, S.; Horgan, H.</p> <p>2004-12-01</p> <p>The Terror Rift region is an important key to understanding the timing and kinematics of neotectonic rifting between East and West Antarctica. In January/February 2004, a 30-day geophysical cruise (NBP04-01) was conducted in the western <span class="hlt">Ross</span> Sea with the goal of analyzing faulting associated with the Terror Rift. New, east-west, multichannel seismic reflection profiles (line spacing between 5-15 km) have revealed new details about a prominent fault zone striking generally N-S between 166°E and 167.5°E within the western <span class="hlt">Ross</span> Sea. The fault zone can be traced along strike for at least 150km. Initial comparison to previous seismic surveys correlates this fault zone with the margin of the "Discovery Graben" and the "Lee Arch" in the eastern part of the Terror Rift. Our new lines show that the faults clearly have normal displacement, having down-to-the-west offset in the east, and down-to-the-east offset in the west. Bedding in the fault zone defines an antiformal structure, and faults change dip and sense of normal displacement across the antiformal hinge zone. On some seismic profiles a prominent unconformity truncates the stratigraphic interval affected by intense faulting, with fewer younger faults cutting the unconformity and reaching the seafloor. On other lines the interval of intense faulting is at the seafloor and the unconformity is absent, possibly indicating more recent glacial erosion. Comparison of the reflectors and unconformities within this fault zone to the dated cores of the Cape Roberts Project should allow us to reconstruct a detailed interpretation of the timing and history of rifting in the region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080036090&hterms=concentration&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dconcentration','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080036090&hterms=concentration&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dconcentration"><span><span class="hlt">Ross</span> Sea Polynyas: Response of Ice Concentration Retrievals to Large Areas of Thin Ice</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kwok, R.; Comiso, J. C.; Martin, S.; Drucker, R.</p> <p>2007-01-01</p> <p>For a 3-month period between May and July of 2005, we examine the response of the Advanced Microwave Scanning Radiometer (AMSR-E) Enhanced NASA Team 2 (NT2) and AMSR-E Bootstrap (ABA) ice concentration algorithms to large areas of thin ice of the <span class="hlt">Ross</span> Sea polynyas. Coincident Envisat Synthetic Aperture Radar (SAR) coverage of the region during this period offers a detailed look at the development of the polynyas within several hundred kilometers of the ice front. The high-resolution imagery and derived ice motion fields show bands of polynya ice, covering up to approximately 105 km(sup 2) of the <span class="hlt">Ross</span> Sea, that are associated with wind-forced advection. In this study, ice thickness from AMSR-E 36 GHz polarization information serves as the basis for examination of the response. The quality of the thickness of newly formed sea ice (<10 cm) from AMSR-E is first assessed with thickness estimates derived from ice surface temperatures from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The effect of large areas of thin ice in lowering the ice concentration estimates from both NT2/ABA approaches is clearly demonstrated. Results show relatively robust relationships between retrieved ice concentrations and thin ice thickness estimates that differ between the two algorithms. These relationships define the approximate spatial coincidence of ice concentration and thickness isopleths. Using the 83% (ABA) and 91% (NT2) isopleths as polynya boundaries, we show that the computed coverage compares well with that using the estimated 10-cm thickness contour. The thin ice response characterized here suggests that in regions with polynyas, the retrieval results could be used to provide useful geophysical information, namely thickness and coverage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMED41A0839R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMED41A0839R"><span>Sustainable Seas Student Monitoring Project at the Branson School in <span class="hlt">Ross</span>, CA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rainsford, A.; Soave, K.; Costolo, R.; Kudler, J.; Emunah, M.; Hatfield, J.; Kiyasu, J.</p> <p>2015-12-01</p> <p>Alina Rainsford, Kathy Soave, Julia Kudler, Jane Hatfield, Melea Emunah, Rose Costelo, Jenna Kiyasu, Amy Dean and Sustainable Seas Monitoring Project, Branson School, <span class="hlt">Ross</span>, CA, United States, Farallones Marine Sanctuary Association, San Francisco, CA, United StatesAbstract:The Sustainable Seas Student Monitoring Project at the Branson School in <span class="hlt">Ross</span>, CA has monitored Duxbury Reef in Bolinas, CA since 1999, in cooperation with the Farallones Marine Sanctuary Association and the Gulf of Farallones National Marine Sanctuary. Goals of this student-run project include: 1) To monitor the rocky intertidal habitat and develop a baseline database of invertebrates and algal density and abundance; 2) To contribute to the conservation of the rocky intertidal habitat through education of students and visitors about intertidal species; 3) To increase stewardship in the Gulf of the Farallones National Marine Sanctuary; and 4) To contribute abundance and population data on key algae and invertebrate species to the national database, LiMPETS (Long Term Monitoring Program & Experiential Training for Students). Each fall student volunteers complete an intensive training course on the natural history of intertidal invertebrates and algae, identification of key species, rocky intertidal monitoring techniques, and history of the sanctuary. Students identify and count key invertebrate and algae species along two permanent transects and, using randomly determined points, within two permanent 200 m2 areas, in fall, winter, and late spring. Using data from the previous years, we will compare population densities, seasonal abundance and long-term population trends of key algal and invertebrate species, including Tegula funebralis, Anthopluera elegantissima, Cladophora sp. and Fucus sp.. Future analyses and investigations will include intertidal abiotic factors (including water temperature, pH and human foot-traffic) to enhance insights into the Duxbury Reef ecosystem, in particular, the high</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8525H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8525H"><span>Soil thermal regime on ice-free areas in Livingston Island and James <span class="hlt">Ross</span> Island, Antarctic Peninsula region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hrbáček, Filip; Oliva, Marc; Láska, Kamil; Ruiz-Fernández, Jesús; Ángel de Pablo, Miguel; Vieira, Gonçalo; Ramos, Miguel; Nývlt, Daniel</p> <p>2016-04-01</p> <p>Permafrost and active layer are considered prominent components of the Cryosphere, which react very sensitively to small climate variations. The Antarctic Peninsula (AP) region is considered as one of the fastest warming regions on Earth, where mean annual air temperature locally increased more than 2.5°C over the last 60 years. Significant climate differences are found between the eastern and western sides of the AP. While mean annual air temperatures (MAAT) oscillate around -1 to -2 °C and precipitation reach 800 mm w.e. year-1 in the western AP, the MAAT in the eastern AP are below -6 °C and precipitation does not exceed 500 mm. These differences determine different permafrost thickness and spatial distribution in these two regions, as well as diverse patterns of active layer dynamics. With the purpose to better understand the factors controlling the soil thermal regime in maritime permafrost environments, we examine data from 2014 acquired from several sites in Livingston Island (western AP) and James <span class="hlt">Ross</span> Island (eastern AP). The study sites show similar characteristics in terms of topography (slope < 7°) and altitude (50 to 100 m a.s.l.). Air temperature, soil thermal regime at 5 cm and 75 cm depth, as well as active layer thickness and its evolution were analysed. Mean air temperature over the study period varied between -2.6 to -2.7 °C on the different monitoring sites in Livingston Island, while in James <span class="hlt">Ross</span> Island ranged from -7.0 to -7.9 °C. Mean soil temperature at 5 cm depth was slightly higher than air temperature in both areas: -0.7 to -1.3 °C in Livingston Island and -6.2 to -6.3 °C in James <span class="hlt">Ross</span> Island; the same occurred for soil temperature at 75 cm: -0.4 to -0.7 °C in Livingston Island and -6.0 to -6.6 °C James <span class="hlt">Ross</span> Island. Significantly lower values of mean daily amplitude of soil temperature at 5 cm depth and the freezing n-factor values observed during the freezing season on Livingston Island suggest a pronounced insulating effect</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.V23D2103M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.V23D2103M"><span>Controlled-source seismic investigations of the crustal structure beneath Erebus volcano and <span class="hlt">Ross</span> Island, Antarctica: Preliminary Results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maraj, S.; Kyle, P. R.; Zandomeneghi, D.; Knox, H. A.; Aster, R. C.; Snelson, C. M.; Miller, P. E.; Kaip, G. M.</p> <p>2009-12-01</p> <p>During the 2008-09 Austral summer field season we undertook a controlled-source seismic experiment (Tomo-Erebus, TE) to examine the shallow magmatic system beneath the active Erebus volcano (TE-3D) and the crustal structure beneath <span class="hlt">Ross</span> Island. Here we report on the TE-2D component, which was designed to produce a two-dimensional P-wave velocity model along an east-west profile across <span class="hlt">Ross</span> Island. Marine geophysical observations near <span class="hlt">Ross</span> Island have identified the north-south trending Terror Rift within the older and broader Victoria Land Basin, which are a component of the intraplate West Antarctic Rift System. Mount Erebus and <span class="hlt">Ross</span> Island are circumstantially associated with the Terror Rift and its thin (~20 km) crust. The nature, extent and role of the Terror Rift in controlling the evolution of <span class="hlt">Ross</span> Island volcanism and the on-going eruptive activity of Erebus volcano are unknown. In TE-2D, we deployed 21 seismic recorders (Ref Tek 130) with three-component 4.5 Hz geophones (Sercel L-28-3D) along a 90-km east-west line between Capes Royds and Crozier. These were supplemented by 79 similar instruments deployed for the high-resolution TE-3D experiment within a 3 x 3 km grid around the summit crater of Erebus, an array of 8 permanent short period and broadband sensors used to monitor the activity of Erebus and 23 three-component sensors (Guralp CMG-40T, 30s-100 Hz) positioned around the flanks and summit of Erebus. Fifteen chemical sources were loaded in holes drilled about 15 m deep in the snow and ice. The size of these shots ranged from 75 to 600 kg of ANFO with the largest shots at the ends of the profile. An additional shot was detonated in the sea (McMurdo Sound) using 200 kg of dynamite. Due to the rugged terrain, short field seasons and large area to be covered, the seismometer spacing along the TE-2D profile is quite large (~ 5 km spacing), resulting in poor near-surface data resolution. However, the data have a high signal to noise ratio with clear</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20857595','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20857595"><span>"All this that has happened to me shouldn't happen to nobody else": Loretta <span class="hlt">Ross</span> and the Women of Color Reproductive Freedom Movement of the 1980s.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nelson, Jennifer</p> <p>2010-01-01</p> <p>Loretta <span class="hlt">Ross</span> exemplifies women of color feminist participation in and transformation of the women's health movement of the 1970s and 1980s. <span class="hlt">Ross</span> helped build a women's health movement that by the late 1980s made the demands of women of color central. This movement was attractive to many women of color who had rejected the collapse of a broader women's health movement into the abortion rights movement as too narrowly focused. Many women of color activists, including <span class="hlt">Ross</span>, argued that the emphasis on abortion rights and choice failed to address the linked socioeconomic and community health issues confronted by many women of color and poor women. <span class="hlt">Ross</span>'s work spurred coalition building among white women and women of color that focused on expanding reproductive justice and women's health beyond legal abortion. By the 1990s these efforts had produced a vibrant and engaged feminist reproductive justice movement that promoted the socioeconomics of good health for all women.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20018521','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20018521"><span>The modified <span class="hlt">Ross</span> operation using a Dacron prosthetic vascular jacket does prevent pulmonary autograft dilatation at 4.5-year follow-up.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Al Rashidi, Faleh; Bhat, Misha; Höglund, Peter; Meurling, Carl; Roijer, Anders; Koul, Bansi</p> <p>2010-04-01</p> <p>Following the <span class="hlt">Ross</span> operation, pulmonary autografts tend to dilate over time. This study researches the fate of the pulmonary autograft - at 4.5 years following the modified <span class="hlt">Ross</span> operation - with special reference to the impact of the modification on (a) pulmonary autograft dilatation, (b) the neo-aortic root geometry, (c) neo-aortic valve function and (d) the coronary artery reserve. A total of 26 patients who underwent the <span class="hlt">Ross</span> operation were included in this study; of these, 13 consecutive patients underwent a modified <span class="hlt">Ross</span> operation in which the free-standing autograft root was supported externally by a Dacron vascular prosthetic jacket (DVPJ). These patients were compared to a cohort of 13 matched patients who were operated on using the conventional <span class="hlt">Ross</span> technique; all patients were followed up prospectively by echocardiography studies. The patients who underwent the modified <span class="hlt">Ross</span> operation were also subjected to bicycle ergometry. At the 47-month median follow-up, there was no significant increase in the size of the entire neo-aortic root in the patients who underwent the modified <span class="hlt">Ross</span> operation; in addition, the geometry of the neo-aortic root was also preserved and the left ventricular function had improved significantly, whilst the aortic valve function and excursion remained satisfactory. All patients, with one exception, in the modified <span class="hlt">Ross</span> operation group exhibited normal exercise capacity. By contrast, there were significant differences in diameters of the aortic root - between the two surgical techniques in favour of the modified <span class="hlt">Ross</span> technique - following a median follow-up of 23 months in the patients subjected to the conventional <span class="hlt">Ross</span> operation. Provision of external support to the entire pulmonary autograft with a DVPJ prevents its dilatation following free-standing pulmonary autograft <span class="hlt">Ross</span> operation when evaluated at the 4.5-year follow-up. The function and the geometry of the neo-aortic root are not affected negatively by this modification and</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.5309T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.5309T"><span>Ice core reconstruction of sea ice change in the Amundsen-<span class="hlt">Ross</span> Seas since 1702 A.D.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thomas, Elizabeth R.; Abram, Nerilie J.</p> <p>2016-05-01</p> <p>Antarctic sea ice has been increasing in recent decades, but with strong regional differences in the expression of sea ice change. Declining sea ice in the Bellingshausen Sea since 1979 (the satellite era) has been linked to the observed warming on the Antarctic Peninsula, while the <span class="hlt">Ross</span> Sea sector has seen a marked increase in sea ice during this period. Here we present a 308 year record of methansulphonic acid from coastal West Antarctica, representing sea ice conditions in the Amundsen-<span class="hlt">Ross</span> Sea. We demonstrate that the recent increase in sea ice in this region is part of a longer trend, with an estimated ~1° northward expansion in winter sea ice extent (SIE) during the twentieth century and a total expansion of ~1.3° since 1702. The greatest reconstructed SIE occurred during the mid-1990s, with five of the past 30 years considered exceptional in the context of the past three centuries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...815...56G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...815...56G"><span>A New Analysis of the Two Classical ZZ Ceti White Dwarfs GD 165 and <span class="hlt">Ross</span> 548. I. Photometry and Spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Giammichele, N.; Fontaine, G.; Bergeron, P.; Brassard, P.; Charpinet, S.; Pfeiffer, B.; Vauclair, G.</p> <p>2015-12-01</p> <p>We present the first of a two-part seismic analysis of the two bright hot ZZ Ceti stars GD 165 and <span class="hlt">Ross</span> 548. In this first part, we report the results of frequency extraction exercises based on time-series data sets of exceptional quality. We uncovered up to 13 independent pulsation modes in GD 165, regrouped into six main frequency multiplets. These include 9 secure (signal-to-noise ratio, S/N > 4) detections and 4 possible ones (4 ≥ S/N ≥ 3). Likewise, we isolated 11 independent modes in <span class="hlt">Ross</span> 548 (9 secure and 2 possible detections), also regrouped into 6 multiplets. The multiplet structure is likely caused by rotational splitting. We also provide updated estimates of the time-averaged atmospheric properties of these two pulsators in the light of recent developments on the front of atmospheric modeling for DA white dwarfs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoRL..41.3510S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoRL..41.3510S"><span>Twentieth century sea-ice trends in the <span class="hlt">Ross</span> Sea from a high-resolution, coastal ice-core record</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sinclair, Kate E.; Bertler, Nancy A. N.; Bowen, Melissa M.; Arrigo, Kevin R.</p> <p>2014-05-01</p> <p>We present the first proxy record of sea-ice area (SIA) in the <span class="hlt">Ross</span> Sea, Antarctica, from a 130 year coastal ice-core record. High-resolution deuterium excess data show prevailing stable SIA from the 1880s until the 1950s, a 2-5% reduction from the mid-1950s to the early-1990s, and a 5% increase after 1993. Additional support for this reconstruction is derived from ice-core methanesulphonic acid concentrations and whaling records. While SIA has continued to decline around much of the West Antarctic coastline since the 1950s, concurrent with increasing air and ocean temperatures, the underlying trend is masked in the <span class="hlt">Ross</span> Sea by a switch to positive SIA anomalies since the early-1990s. This increase is associated with a strengthening of southerly winds and the enhanced northward advection of sea ice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22521791','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22521791"><span>A NEW ANALYSIS OF THE TWO CLASSICAL ZZ CETI WHITE DWARFS GD 165 AND <span class="hlt">ROSS</span> 548. I. PHOTOMETRY AND SPECTROSCOPY</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Giammichele, N.; Fontaine, G.; Bergeron, P.; Brassard, P.; Charpinet, S.; Vauclair, G.; Pfeiffer, B.</p> <p>2015-12-10</p> <p>We present the first of a two-part seismic analysis of the two bright hot ZZ Ceti stars GD 165 and <span class="hlt">Ross</span> 548. In this first part, we report the results of frequency extraction exercises based on time-series data sets of exceptional quality. We uncovered up to 13 independent pulsation modes in GD 165, regrouped into six main frequency multiplets. These include 9 secure (signal-to-noise ratio, S/N > 4) detections and 4 possible ones (4 ≥ S/N ≥ 3). Likewise, we isolated 11 independent modes in <span class="hlt">Ross</span> 548 (9 secure and 2 possible detections), also regrouped into 6 multiplets. The multiplet structure is likely caused by rotational splitting. We also provide updated estimates of the time-averaged atmospheric properties of these two pulsators in the light of recent developments on the front of atmospheric modeling for DA white dwarfs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V31B2697R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V31B2697R"><span>Using melt inclusions to track the evolution of primitive alkalic magmas from <span class="hlt">Ross</span> Island, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rasmussen, D. J.; Kyle, P. R.; Wallace, P. J.</p> <p>2013-12-01</p> <p>Melt inclusions (MI) provide a means for measuring the dissolved volatile (H2O, CO2, S, Cl, F), major and trace element compositions of magmas at depth. Such data are valuable for assessing the physical and chemical conditions within a magmatic system by providing snapshots of magma compositions during ascent and evolution. Here we examine MI in 9 samples of rapidly quenched basanitic ash and hyaloclastite from three locations (Hut Point, Mt. Terror, Mt. Bird) on <span class="hlt">Ross</span> Island, Antarctica, which radially surround the active, phonolitic Erebus volcano. <span class="hlt">Ross</span> Island is an intraplate volcanic center located at the southern end of the Terror Rift, an area of active continental extension. Geophysical data show that below the 19-27 km thick crust is a localized region of anomalously hot upwelling mantle. We analyzed volatiles and major elements in 93 olivine-hosted (Fo 78.2-88.3) MI using FTIR spectroscopy and electron microprobe analysis, and all compositions were corrected for the effects of post-entrapment olivine crystallization. Preliminary results show the MI have a range of basanite compositions (SiO2 39.1-45.2 wt.%; Mg# 50.1-66.5). The MI major element trends further suggest the 9 samples are genetically related and may have a common low degree partial melt parental magma. CO2 contents range from ~0.1 to 0.85 wt.%, which are amongst the highest ever measured in MI. H2O contents are ~1 to 1.9 wt.%. The MI also have high concentrations of S, Cl, and F with maximum values of 0.27, 0.22, and 0.14 wt.%, respectively. The H2O and CO2 concentrations require entrapment pressures between ~250 and 600 MPa. Thus, the MI record a magmatic history that begins at near-Moho depths and is exceptionally CO2-rich. Because of its low solubility in magmas CO2 must be the major volatile driving the eruption of these alkalic magmas. More evolved Erebus MI (SiO2 43.4-53.6 wt.%; Mg# 32.9-55.1) from an earlier study [1] have consistently lower H2O concentrations. [1] Oppenheimer et al</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JVGR..310..137S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JVGR..310..137S"><span>Unravelling textural heterogeneity in obsidian: Shear-induced outgassing in the Rocche <span class="hlt">Rosse</span> flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shields, J. K.; Mader, H. M.; Caricchi, L.; Tuffen, H.; Mueller, S.; Pistone, M.; Baumgartner, L.</p> <p>2016-01-01</p> <p>Obsidian flow emplacement is a complex and understudied aspect of silicic volcanism. Of particular importance is the question of how highly viscous magma can lose sufficient gas in order to erupt effusively as a lava flow. Using an array of methods we study the extreme textural heterogeneity of the Rocche <span class="hlt">Rosse</span> obsidian flow in Lipari, a 2 km long, 100 m thick, ~ 800 year old lava flow, with respect to outgassing and emplacement mechanisms. 2D and 3D vesicle analyses and density measurements are used to classify the lava into four textural types: 'glassy' obsidian (< 15% vesicles), 'pumiceous' lava (> 40% vesicles), high aspect ratio, 'shear banded' lava (20-40% vesicles) and low aspect ratio, 'frothy' obsidian with 30-60% vesicles. Textural heterogeneity is observed on all scales (m to μm) and occurs as the result of strongly localised strain. Magnetic fabric, described by oblate and prolate susceptibility ellipsoids, records high and variable degrees of shearing throughout the flow. Total water contents are derived using both thermogravimetry and infrared spectroscopy to quantify primary (magmatic) and secondary (meteoric) water. Glass water contents are between 0.08-0.25 wt.%. Water analysis also reveals an increase in water content from glassy obsidian bands towards 'frothy' bands of 0.06-0.08 wt.%, reflecting preferential vesiculation of higher water bands and an extreme sensitivity of obsidian degassing to water content. We present an outgassing model that reconciles textural, volatile and magnetic data to indicate that obsidian is generated from multiple shear-induced outgassing cycles, whereby vesicular magma outgasses and densifies through bubble collapse and fracture healing to form obsidian, which then re-vesiculates to produce 'dry' vesicular magma. Repetition of this cycle throughout magma ascent results in the low water contents of the Rocche <span class="hlt">Rosse</span> lavas and the final stage in the degassing cycle determines final lava porosity. Heterogeneities in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA....11755B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA....11755B"><span>Biosiliceous sediments in the cape Hallett area (<span class="hlt">Ross</span> Sea, Antarctica): paleoenvironmental considerations.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brambati, A.; Colizza, E.; Finocchiaro, F.; Fontolan, G.; Giglio, F.; Langone, L.; Ravaioli, M.; Tuzzi, E.</p> <p>2003-04-01</p> <p>The study of expanded marine sequences of Cenozoic sediments of the Southern Ocean is crucial for a detailed reconstruction of the palaeoenvironmental changes occurred in the austral hemisphere. Into the shelf basins of the <span class="hlt">Ross</span> sea, sedimentation rates of modern fine sediment are generally low, with values of 20- 24 cm ka-1 in the deepest parts of the Joides Basin and slightly increasing up-core. On the other hand, into Granite Harbor the diatomaceous ooze is accumulating very fast (250 cm ka-1), reinforcing the observation that bays and fjords have high potential to preserve high-resolution sedimentary records. During the 2001-2002 oceanographic cruise in the western <span class="hlt">Ross</span> Sea, core ANTA02-CH41 was collected in the bay near Cape Hallett. The core is characterized, from top to bottom, by about 2 m of volcanoclastic muddy sand. In the lower unit, grain-size decreases and 2 laminated intervals can be distinguished: a) between 207 and 253 cm, where laminae are weavy and irregular; b) from 307 cm to the bottom, the laminae are parallel, few mm to cm thick. In the muddy unit a preliminary sedimentation rate of 72 cm ka-1 was calculated. Laminae show strong colour variation from black to pale yellow, through several shades of olive (Munsell Soil Color Chart). Smear slides observation has pointed out that pale laminae are mainly composed by diatoms frustules, while in dark laminae volcanoclastic silt content is higher. These observations, supported by 14C AMS dating, grain size analysis, and the high values of organic carbon and biogenic silica highlight open sea conditions with high diatom productivity during the early phase of the Holocene. Further analyses are in progress for a better definition of the laminae composition. If this laminated sediment would depict a varved-like sedimentation, then the sediment accumulation rate of these levels would be extremely high, thus indicating that this site is particularly suitable for studying the very high-frequency climatic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17198810','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17198810"><span>Pulmonary homograft muscle reduction to reduce the risk of homograft stenosis in the <span class="hlt">Ross</span> procedure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schmidtke, Claudia; Dahmen, Gerlinde; Graf, Bernhard; Sievers, Hans-H</p> <p>2007-01-01</p> <p>The <span class="hlt">Ross</span> procedure has gained increasing interest as an attractive alternative for aortic valve replacement. Despite its advantages, there is a certain risk of structural valve deterioration, especially of the pulmonary homograft as a result of shrinkage and subsequent stenosis predominantly at the muscular annulus. Theoretically, reduction of homograft muscle tissue could reduce this risk. From February 1996 through December 2002, a total of 238 patients (mean age 44 +/- 13.2 years) underwent the <span class="hlt">Ross</span> procedure with the subcoronary technique with follow-up investigations before discharge and after 12 and 24 months. To estimate the importance of homograft muscle reduction within our institution-specific risk factor scale for change of transhomograft pressure gradient with time, we performed a generalized estimating equation approach, which identified homograft muscle reduction, higher body surface area in male patients, younger patient age, smaller homograft diameter, blood transfusions, and follow-up time as independent risk factors demonstrating a high beta value (-2.8638) for muscle reduction. To find out whether muscle reduction influences transhomograft pressure gradient, we compared patients with (group A, n = 39) and without (group B, n = 199) muscle reduction. The other mentioned independent risk factors were not different between groups, except for blood transfusions (group A greater than B, P < .01), indicating a negative bias for group A. The maximum pressure gradient across the homograft was lower in patients with muscle reduction before discharge (4.5 +/- 2.8 mm Hg group A vs 6.2 +/- 3.8 mm Hg group B, P = .004) and after 1 (9.3 +/- 5.8 vs 13.1 +/- 8.4 mm Hg, P = .028) and 2 years (10.8 +/- 7.6 vs 13.7 +/- 7.5 mm Hg, P = .013). No significant differences were found concerning homograft insufficiency. We provide some evidence that transhomograft pressure gradient can be reduced significantly within the first 2 years after operation by homograft muscle</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSHE44B1500F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSHE44B1500F"><span>Temporal variability of the Circumpolar Deep Water inflow onto the <span class="hlt">Ross</span> Sea continental shelf</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Falco, P.; Castagno, P.; Budillon, G.; Spezie, G.</p> <p>2016-02-01</p> <p>The Circumpolar Deep Water (CDW) intrusion on the Antarctic continental shelves is the primary source of heat, salt and nutrients playing a major role on the shelf physical and biological processes. Different studies have analyzed the processes responsible for the transport of CDW across the <span class="hlt">Ross</span> Sea shelf break, but until now, there are no continuous observations that investigate the time of the intrusions. Besides, few works focused on the effect of the tide that controls the intrusion itself. In the <span class="hlt">Ross</span> Sea, the CDW intrudes onto the shelf in several locations mostly along the troughs, such as the Glomar Challenger, the Joides and the Drygalski. We use hydrographic observations and three moorings placed (one) on the outer shelf in the middle of the Drygalski Trough and (two) on the upper slope at the mouth of the Glomar Challenger basin, in order to characterize the spatial and temporal variability of the CDW inflow onto the shelf. Our data span from 2004 to 2014. In the Drygalski Trough the CDW enters as a thick layer of about 150 m between 250 - 400 m moving upward toward south. At the mooring location, about 50 Km from the shelf break, two main CDW cores can be observed: one on east side of the trough spreading along the west slope of Mawson Bank from about 200 m to the bottom and the other one in the central-west side from 200 m to about 350 m. A signature of this lighter and relatively warm water is detected by the instruments on the mooring at bottom of the Drygalski Trough. The CDW intrusion at the bottom of the trough is strictly related to the diurnal and spring/neap tidal cycles, but a strong seasonal variability of the CDW is clear. A strong inflow of CDW is observed every year at the end of December (after few months that the salinity minimum is registered), while the CDW inflow is at its seasonal minimum during the end of the austral summer in correspondence of the salinity maximum associated with the High Salinity Shelf Water (HSSW). Indeed, the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011DSRI...58.1002B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011DSRI...58.1002B"><span>Thermohaline variability and Antarctic bottom water formation at the <span class="hlt">Ross</span> Sea shelf break</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Budillon, Giorgio; Castagno, Pasquale; Aliani, Stefano; Spezie, Giancarlo; Padman, Laurie</p> <p>2011-10-01</p> <p>We use hydrological and current meter data collected in the <span class="hlt">Ross</span> Sea, Antarctica between 1995 and 2006 to describe the spatial and temporal variability of water masses involved in the production of Antarctic Bottom Water (AABW). Data were collected in two regions of known outflows of dense shelf water in this region; the Drygalski Trough (DT) and the Glomar-Challenger Trough (GCT). Dense shelf water just inshore of the shelf break is dominated by High Salinity Shelf Water (HSSW) in the DT and Ice Shelf Water (ISW) in the GCT. The HSSW in the northern DT freshened by ˜0.06 in 11 y, while the ISW in the northern GCT freshened by ˜0.04 in 8 y and warmed by ˜0.04 °C in 11 y, dominated by a rapid warming during austral summer 2001/02. The Antarctic Slope Front separating the warm Circumpolar Deep Water (CDW) from the shelf waters is more stable near GCT than near DT, with CDW and mixing products being found on the outer DT shelf but not on the outer GCT shelf. The different source waters and mixing processes at the two sites lead to production of AABW with different thermohaline characteristics in the central and western <span class="hlt">Ross</span> Sea. Multi-year time series of hydrography and currents at long-term moorings within 100 km of the shelf break in both troughs confirm the interannual signals in the dense shelf water and reveal the seasonal cycle of water mass properties. Near the DT the HSSW salinities experienced maxima in March/April and minima in September/October. The ISW in the GCT is warmest in March/April and coolest between August and October. Mooring data also demonstrate significant high-frequency variability associated with tides and other processes. Wavelet analysis of near-bottom moored sensors sampling the dense water cascade over the continental slope west of the GCT shows intermittent energetic pulses of cold, dense water with periods from ˜32 h to ˜5 days.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMPP33B1935R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMPP33B1935R"><span>Coulman High Project Site Survey Interdisciplinary Outcomes: What Lies Beneath The <span class="hlt">Ross</span> Ice Shelf</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rack, F. R.; Zook, R.; Mahacek, P.; Carroll, D.; Levy, R. H.; Limeburner, R.; Williams, M.; Stewart, C.; C/O Andrill Smo, A.</p> <p>2011-12-01</p> <p>The ANDRILL Coulman High (CH) Project Site Surveys were an international effort conducted from November 2010 through January 2011. These surveys achieved all their primary and secondary objectives and resulted in an unexpected biological discovery at the lower boundary of the <span class="hlt">Ross</span> Ice Shelf (RIS), which demonstrates the role of serendipity in scientific research. The surveys followed a safe traverse route to CH across the RIS using a ground-penetrating radar system supplemented by previously collected airborne radar. Four GPS stations and a weather station were established to monitor lateral and vertical ice motions and environmental conditions. A series of combined US-NZ field camps on the RIS were occupied and the ANDRILL hot water drill (HWD) system was used to melt numerous holes through 250-275 meters of ice shelf. Oceanographic moorings comprised of inductive sensors were deployed through the RIS at two sites and were recovered to the ice surface after two months. The NZ mooring was redeployed to conduct long-term observations through the water column at CH. Video camera observations of the interior and basal surface of the ice shelf and benthic observations of the seafloor were integrated with conductivity-temperature-depth (CTD) measurements at each site. The Submersible Capable of under-Ice Navigation and Imaging (SCINI) underwater remotely operated vehicle (ROV) was deployed at two sites through 260 meters of ice to explore the underside of the ice shelf while conducting operational testing. This was the first time that SCINI was deployed through an ice shelf. SCINI discovered an unusual biological community living in the ice at the lower surface of the ice shelf and recovered biological samples using an improvised suction pump sampler. These samples and extensive imagery are being further investigated to determine the nature of this newly discovered ecosystem. The biological discovery at the base of the RIS highlights the importance of continued</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015BGeo...12.6881D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015BGeo...12.6881D"><span>Carbonate saturation state of surface waters in the <span class="hlt">Ross</span> Sea and Southern Ocean: controls and implications for the onset of aragonite undersaturation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>DeJong, H. B.; Dunbar, R. B.; Mucciarone, D.; Koweek, D. A.</p> <p>2015-12-01</p> <p>Predicting when surface waters of the <span class="hlt">Ross</span> Sea and Southern Ocean will become undersaturated with respect to biogenic carbonate minerals is challenging in part due to the lack of baseline high-resolution carbon system data. Here we present ~ 1700 surface total alkalinity measurements from the <span class="hlt">Ross</span> Sea and along a transect between the <span class="hlt">Ross</span> Sea and southern Chile from the austral autumn (February-March 2013). We calculate the saturation state of aragonite (ΩAr) and calcite (Ω Ca) using measured total alkalinity and pCO2. In the <span class="hlt">Ross</span> Sea and south of the Polar Front, variability in carbonate saturation state (Ω) is mainly driven by algal photosynthesis. Freshwater dilution and calcification have minimal influence on Ω variability. We estimate an early spring surface water ΩAr value of ~ 1.2 for the <span class="hlt">Ross</span> Sea using a total alkalinity-salinity relationship and historical pCO2 measurements. Our results suggest that the <span class="hlt">Ross</span> Sea is not likely to become undersaturated with respect to aragonite until the year 2070.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015BGD....12.8429D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015BGD....12.8429D"><span>Carbonate saturation state of surface waters in the <span class="hlt">Ross</span> Sea and Southern Ocean: controls and implications for the onset of aragonite undersaturation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>DeJong, H. B.; Dunbar, R. B.; Mucciarone, D. A.; Koweek, D. A.</p> <p>2015-06-01</p> <p>Predicting when surface waters of the <span class="hlt">Ross</span> Sea and Southern Ocean will become undersaturated with respect to biogenic carbonate minerals is challenging in part due to the lack of baseline high resolution carbon system data. Here we present ~ 1700 surface total alkalinity measurements from the <span class="hlt">Ross</span> Sea and along a transect between the <span class="hlt">Ross</span> Sea and southern Chile from the austral autumn (February-March 2013). We calculate the saturation state of aragonite (ΩAr) and calcite (ΩCa) using measured total alkalinity and pCO2. In the <span class="hlt">Ross</span> Sea and south of the Polar Front, variability in carbonate saturation state (Ω) is mainly driven by algal photosynthesis. Freshwater dilution and calcification have minimal influence on Ω variability. We estimate an early spring surface water ΩAr value of ~ 1.2 for the <span class="hlt">Ross</span> Sea using a total alkalinity-salinity relationship and historical pCO2 measurements. Our results suggest that the <span class="hlt">Ross</span> Sea is not likely to become undersaturated with respect to aragonite until the year 2070.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JVGR..297...89C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JVGR..297...89C"><span>Volcano-ice-sea interaction in the Cerro Santa Marta area, northwest James <span class="hlt">Ross</span> Island, Antarctic Peninsula</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Calabozo, Fernando M.; Strelin, Jorge A.; Orihashi, Yuji; Sumino, Hirochika; Keller, Randall A.</p> <p>2015-05-01</p> <p>We present here the results of detailed mapping, lithofacies analysis and stratigraphy of the Neogene James <span class="hlt">Ross</span> Island Volcanic Group (Antarctic Peninsula) in the Cerro Santa Marta area (northwest of James <span class="hlt">Ross</span> Island), in order to give constraints on the evolution of a glaciated volcanic island. Our field results included recognition and interpretation of seventeen volcanic and glacial lithofacies, together with their vertical and lateral arrangements, supported by four new unspiked K-Ar ages. This allowed us to conclude that the construction of the volcanic pile in this area took place during two main eruptive stages (Eruptive Stages 1 and 2), separated from the Cretaceous bedrock and from each other by two major glacial unconformities (U1 and U2). The U1 unconformity is related to Antarctic Peninsula Ice sheet expansion during the late Miocene (before 6.2 Ma) and deposition of glacial lithofacies in a glaciomarine setting. Following this glacial advance, Eruptive Stage 1 (6.2-4.6 Ma) volcanism started with subaerial extrusion of lava flows from an unrecognized vent north of the study area, with eruptions later fed from vent/s centered at Cerro Santa Marta volcano, where cinder cone deposits and a volcanic conduit/lava lake are preserved. These lava flows fed an extensive (> 7 km long) hyaloclastite delta system that was probably emplaced in a shallow marine environment. A second unconformity (U2) was related to expansion of a local ice cap, centered on James <span class="hlt">Ross</span> Island, which truncated all the eruptive units of Eruptive Stage 1. Concomitant with glacier advance, renewed volcanic activity (Eruptive Stage 2) started after 4.6 Ma and volcanic products were fed again by Cerro Santa Marta vents. We infer that glaciovolcanic eruptions occurred under a moderately thin (~ 300 m) glacier, in good agreement with previous estimates of paleo-ice thickness for the James <span class="hlt">Ross</span> Island area during the Pliocene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.2510K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.2510K"><span>Seismic stratigraphy and tomography in the outer shelf and slope of the Central Basin, <span class="hlt">Ross</span> Sea, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Sookwan; De Santis, Laura; Böhm, Gualtiero; Kuk Hong, Jong; Jin, Young Keun; Geletti, Riccardo; Wardell, Nigel; Petronio, Lorenzo; Colizza, Ester</p> <p>2014-05-01</p> <p>The <span class="hlt">Ross</span> Sea, located between Victoria Land and Marie Byrd Land in Antarctica, is one of the main drainage of the Antarctic Ice Sheet (AIS). Reflection seismic data acquired by many countries during several decades have provided insights into the history of the <span class="hlt">Ross</span> Sea and the AIS evolution. However the majority of the existing seismic data are concentrated in the shelf area, where hiatus formed by grounding ice sheet erosion multiple events prevent to reconstruct the entire sedimentary sequences depositional evolution. On the outer shelf and upper slope, the sedimentary sequences are relatively well preserved. The main purpose of this study is the investigation of the Cenozoic Antarctic Ice Sheet evolution through the seismic sequence analysis of the outer shelf and slope of the Central Basin, in the <span class="hlt">Ross</span> Sea. The data used are the new multi-channel seismic data, KSL12, were acquired on the outer shelf and upper slope of the Central Bain in February 2013 by Korea Polar Research Institute. The reflection seismic data, previously collected by the Italian Antarctic Program (PNRA) and other data available from the Seismic Data Library System (SDLS) are also used for velocity tomography and seismic sequence mapping. The seismic data were processed by a conventional processing flow to produce the seismic profiles. Preliminary results show well-developed prograding wedges at the mouth of glacial troughs, eroded by a major glacial unconformity, the <span class="hlt">Ross</span> Sea Unconformity 4 (RSU-4), correlated to a main event between early- and mid-Miocene. The velocity anomalies shown along KSL12-1 can be interpreted as showing the occurrence of gas and fluids, diagenetic horizons and sediment compactions. The isopach maps of each sequence show the variation of thickness of the sediments depocenter shift. The seismic sequence stratigraphy and acoustic facies analysis provide information about different phases of ice sheet's advance and retreat related to the AIS Cenozoic dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22519968','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22519968"><span>A NEW ANALYSIS OF THE TWO CLASSICAL ZZ CETI WHITE DWARFS GD 165 AND <span class="hlt">ROSS</span> 548. II. SEISMIC MODELING</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Giammichele, N.; Fontaine, G.; Brassard, P.; Charpinet, S.</p> <p>2016-03-15</p> <p>We present the second of a two-part seismic analysis of the bright, hot ZZ Ceti stars GD 165 and <span class="hlt">Ross</span> 548. In this second part, we report the results of detailed searches in parameter space for identifying an optimal model for each star that can account well for the observed periods, while being consistent with the spectroscopic constraints derived in our first paper. We find optimal models for each target that reproduce the six observed periods well within ∼0.3% on the average. We also find that there is a sensitivity on the core composition for <span class="hlt">Ross</span> 548, while there is practically none for GD 165. Our optimal model of <span class="hlt">Ross</span> 548, with its thin envelope, indeed shows weight functions for some confined modes that extend relatively deep into the interior, thus explaining the sensitivity of the period spectrum on the core composition in that star. In contrast, our optimal seismic model of its spectroscopic sibling, GD 165 with its thick envelope, does not trap/confine modes very efficiently, and we find weight functions for all six observed modes that do not extend into the deep core, hence accounting for the lack of sensitivity in that case. Furthermore, we exploit after the fact the observed multiplet structure that we ascribe to rotation. We are able to map the rotation profile in GD 165 (<span class="hlt">Ross</span> 548) over the outermost ∼20% (∼5%) of its radius, and we find that the profile is consistent with solid-body rotation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.5081M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.5081M"><span>Sea ice variability during the Holocene: evidence from marine and ice cores in the <span class="hlt">Ross</span> Sea area, East Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mezgec, Karin; Melis, Romana; Crosta, Xavier; Traversi, Rita; Severi, Mirko; Colizza, Ester; Braida, Martina; Stenni, Barbara</p> <p>2013-04-01</p> <p>High latitudes are particularly interesting places to document natural climate variability. Sea ice is an important element in the climate system because it influences bottom water formation and ocean circulation and regulates the ocean-atmosphere heat exchange. Understanding climate and environmental changes through the reconstruction of past sea ice variability, atmospheric circulation and oceanographic conditions in the Southern Ocean could represent one of the most important keys to predict with confidence future climate changes on global scale. In fact, the oceanic area surrounding Antarctica represents the main source of bottom water formation affecting the global climate through the oceanic circulation. In this study, we present an interdisciplinary proxies analysis considering marine and ice core records, as part of the ESF PolarCLIMATE HOLOCLIP (Holocene climate variability at high-southern latitudes: an integrated perspective) project, to document sea ice variability in the <span class="hlt">Ross</span> Sea continental shelf area. Diatom assemblages from three sediment cores located in the north-western <span class="hlt">Ross</span> Sea (Joides Basin, Cape Hallett and Wood Bay) have been studied and the sea salt Na+ (a potential proxy of sea ice) records from two ice core sites (Taylor Dome and Talos Dome) facing the <span class="hlt">Ross</span> Sea area have been considered. The significant positive correlations among the sea ice diatom Fragilariopsis curta relative abundance and sea salt Na+ records from Talos Dome and Taylor Dome ice cores, suggest that sea salt Na+ could be used as a proxy for sea ice extent and/or duration in the <span class="hlt">Ross</span> Sea area. These preliminary results look as a positive premise in view of integrating proxies from different realms (marine and glacial) in order to achieve a more complete view of the climate and environmental changes occurring during the Holocene. The combination of geological and glacial records will greatly improve our knowledge on paleo sea ice dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AIPC.1479.2195H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AIPC.1479.2195H"><span>ADI FD schemes for the numerical solution of the three-dimensional Heston-Cox-Ingersoll-<span class="hlt">Ross</span> PDE</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haentjens, Tinne</p> <p>2012-09-01</p> <p>This paper deals with the numerical solution of the time-dependent, three-dimensional Heston-Cox-Ingersoll- <span class="hlt">Ross</span> PDE, with all correlations nonzero, for the fair pricing of European call options. We apply a finite difference dis-cretization on non-uniform spatial grids and then numerically solve the semi-discrete system in time by using an Alternating Direction Implicit scheme. We show that this leads to a highly efficient and stable numerical solution method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMEP13A0939R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMEP13A0939R"><span>The Origin of a Layer of Subcircular Mudflakes in the <span class="hlt">Ross</span> Sandstone Formation of County Clare, Ireland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Robinson, K. H.; Kackstaetter, U. R.</p> <p>2015-12-01</p> <p>The west coast of Ireland in County Clare is famous for its Paleozoic stratigraphy containing spectacular exposures of deposits from carbonate shelf, deep marine, slope and deltaic environments, exposed at several distinctive and well-known locations including the Burren, Cliffs of Moher, and Bridges of <span class="hlt">Ross</span>. Underlying the silty sandstones of the Gull Island Formation and overlying the Clare Shale, the Carboniferous <span class="hlt">Ross</span> Sandstone Formation comprises a series of fine-grained sandstone and mudstone deep water turbidite deposits. Approximately a half-kilometer northeast of the Bridges of <span class="hlt">Ross</span> and about 15 meters below the upper boundary of the <span class="hlt">Ross</span> Formation is a particular stratum exhibiting an assemblage of unique circular to ovoid impressions. These features densely cover an exposed horizontal surface of approximately 100 square meters, positioned about 5 meters above and adjacent to a cluster of sand volcanoes. The impressions frequently overlap and completely cover the exposed surface of the rock unit and continue along the same plane of the buried portion of the stratum. Diameters of the impressions range between 2 and 20 centimeters, and many contain clasts of pale grey shale or claystone material. Samples were collected from the layer of interest as well as from subjacent and superjacent strata, spanning a total thickness of just over 1 meter. Thin sections were created and analyzed to determine both composition and estimated porosity of the rock in a continuous vertical cross-section through the series of strata surrounding the impressions. Characteristics of each stratum were examined to explore possible depositional relationships of each layer to the others and to indicate likely diagenetic processes of the subcircular features. Two broad possible origins are discussed: a primary sedimentary origin, i.e. turbidite channel mudflake conglomerate; or a post-depositional soft sediment deformation origin due to either (i) sediment loading and dewatering, (ii</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22740529','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22740529"><span>Serum chemistry and antibodies against pathogens in antarctic fur seals, Weddell seals, crabeater seals, and <span class="hlt">Ross</span> seals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tryland, Morten; Nymo, Ingebjørg H; Nielsen, Ole; Nordøy, Erling S; Kovacs, Kit M; Krafft, Bjørn A; Thoresen, Stein I; Åsbakk, Kjetil; Osterrieder, Klaus; Roth, Swaantje J; Lydersen, Christian; Godfroid, Jacques; Blix, Arnoldus S</p> <p>2012-07-01</p> <p>Information on health parameters, such as antibody prevalences and serum chemistry that can reveal exposure to pathogens, disease, and abnormal physiologic conditions, is scarce for Antarctic seal species. Serum samples from Antarctic fur seals (Arctocephalus gazella, n=88) from Bouvetøya (2000-2001 and 2001-2002), and from Weddell seals (Leptonychotes weddellii, n=20), <span class="hlt">Ross</span> seals (Ommatophoca rossii, n=20), and crabeater seals (Lobodon carcinophagus, n=9) from the pack-ice off Queen Maud Land, Antarctica (2001) were analyzed for enzyme activity, and concentrations of protein, metabolites, minerals, and cortisol. Adult Antarctic fur seal males had elevated levels of total protein (range 64-99 g/l) compared to adult females and pups (range 52-79 g/l). Antarctic fur seals had higher enzyme activities of creatine kinase, lactate dehydrogenase, and amylase, compared to Weddell, <span class="hlt">Ross</span>, and crabeater seals. Antibodies against Brucella spp. were detected in Weddell seals (37%), <span class="hlt">Ross</span> seals (5%), and crabeater seals (11%), but not in Antarctic fur seals. Antibodies against phocine herpesvirus 1 were detected in all species examined (Antarctic fur seals, 58%; Weddell seals, 100%; <span class="hlt">Ross</span> seals, 15%; and crabeater seals, 44%). No antibodies against Trichinella spp., Toxoplasma, or phocine distemper virus (PDV) were detected (Antarctic fur seals were not tested for PDV antibodies). Antarctic seals are challenged by reduced sea ice and increasing temperatures due to climate change, and increased anthropogenic activity can introduce new pathogens to these vulnerable ecosystems and represent a threat for these animals. Our data provide a baseline for future monitoring of health parameters of these Antarctic seal species, for tracking the impact of environmental, climatic, and anthropogenic changes in Antarctica over time.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMPP51B2285L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMPP51B2285L"><span>The Roosevelt Island Climate Evolution (RICE) ice core: climate and ice dynamics of the <span class="hlt">Ross</span> Sea, West Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, J. E.; Brook, E.; Blunier, T.; Severinghaus, J. P.; Bertler, N. A. N.; Waddington, E. D.; Vallelonga, P. T.; Conway, H.; Dahl-Jensen, D.; Buizert, C.; Fudge, T. J.; Parrenin, F.</p> <p>2015-12-01</p> <p>Ice cores drilled in Antarctica have proven to be remarkable archives of past climate, but most have been recovered from the remote Antarctic interior. In contrast, little is known about the climate history of coastal ice domes despite their relevance to ocean-ice interaction and sea level rise. The Roosevelt Island Climate Evolution project (RICE) recovered a 763 m ice core in 2013 from Roosevelt Island, West Antarctica. Located at the edge of the <span class="hlt">Ross</span> Ice Shelf and grounded below sea level, Roosevelt Island is sensitive to oceanic forcing and may provide new information about potential drivers of abrupt interhemispheric climate connections and its location is ideal for exploring the retreat of the West Antarctic Ice Sheet (WAIS) from its glacial maximum through the <span class="hlt">Ross</span> Sea. Here we present a continuous chronology for the RICE Ice Core covering the last 40,000 years with additional evidence of ice dating to at least 80,000 years near the bottom of the core. Both the depth-age relationship and reconstructed profile of annual layer thicknesses can be used to infer changes in climate and the glacial history of the East <span class="hlt">Ross</span> Sea Embayment. The most striking feature of the record occurred during the Antarctic Cold Reversal. At this time a combination of data including thin annual layers, abrupt lowering of δ15N of N2 and δ40Ar in trapped air, and strongly depleted δD of ice suggest either a pronounced change in cyclonic activity and regional storm tracks and/or adjustment in the configuration of the <span class="hlt">Ross</span> Ice Sheet during this period of rapid climate change and sea level rise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Tectp.717..127J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Tectp.717..127J"><span>Variations of the effective elastic thickness over the <span class="hlt">Ross</span> Sea and Transantarctic Mountains and implications for their structure and tectonics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ji, Fei; Gao, Jinyao; Li, Fei; Shen, Zhongyan; Zhang, Qiao; Li, Yongdong</p> <p>2017-10-01</p> <p>The effective elastic thickness (Te) is a proxy for lithospheric strength, and it depends primarily on the thermal gradient and composition of the lithosphere. Accordingly, spatial variations in Te reflect changes in lithospheric properties and can be used to better understand the structure and tectonics of particular regions. In this paper, we investigate the <span class="hlt">Ross</span> Sea and Transantarctic Mountains in terms of Te using gravity and topographic data and the fan wavelet transform technique. The results reveal that relatively high Te values dominate in the extensional basins of the <span class="hlt">Ross</span> Sea and the hinterland of Transantarctic Mountains, whereas very low Te values occur along the Transantarctic Mountain Front and in the deep ocean basin, with the lowest Te values are found the vicinity of <span class="hlt">Ross</span> Island and onshore in northern Victoria Land. In addition, the spatial variations in Te correlate well with lithospheric structure at the regional scale. By combining these findings with published seismic and heat flow data, we conclude that the presence of a zone of anomalously low Te values parallel to the coast indicates that the lithosphere beneath the Transantarctic Mountain Front is extremely weak due to Cenozoic volcanism and extension. The Te values increase from the Transantarctic Mountain Front (7 km) toward the center of the continent ( 80 km), which indicates that the continental lithosphere underlying East Antarctica belongs to the classic Gondwanan craton. The increase in Te indicates that the Transantarctic Mountain Front marks the continent-continent boundary between East Antarctica and West Antarctica. The Te values in the other extensional basins of the <span class="hlt">Ross</span> Sea exhibit little variation and average approximately 35 km. The relatively high Te values are interpreted to indicate that the lithosphere cooled and became mechanically stronger between late Cretaceous extension and Eocene-Neogene deposition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005WRR....4110301W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005WRR....4110301W"><span><span class="hlt">River</span> restoration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wohl, Ellen; Angermeier, Paul L.; Bledsoe, Brian; Kondolf, G. Mathias; Macdonnell, Larry; Merritt, David M.; Palmer, Margaret A.; Poff, N. Leroy; Tarboton, David</p> <p>2005-10-01</p> <p><span class="hlt">River</span> restoration is at the forefront of applied hydrologic science. However, many <span class="hlt">river</span> restoration projects are conducted with minimal scientific context. We propose two themes around which a research agenda to advance the scientific basis for <span class="hlt">river</span> restoration can be built. First, because natural variability is an inherent feature of all <span class="hlt">river</span> systems, we hypothesize that restoration of process is more likely to succeed than restoration aimed at a fixed end point. Second, because physical, chemical, and biological processes are interconnected in complex ways across watersheds and across timescales, we hypothesize that restoration projects are more likely to be successful in achieving goals if undertaken in the context of entire watersheds. To achieve restoration objectives, the science of <span class="hlt">river</span> restoration must include (1) an explicit recognition of the known complexities and uncertainties, (2) continued development of a theoretical framework that enables us to identify generalities among <span class="hlt">river</span> systems and to ask relevant questions, (3) enhancing the science and use of restoration monitoring by measuring the most effective set of variables at the correct scales of measurement, (4) linking science and implementation, and (5) developing methods of restoration that are effective within existing constraints. Key limitations to <span class="hlt">river</span> restoration include a lack of scientific knowledge of watershed-scale process dynamics, institutional structures that are poorly suited to large-scale adaptive management, and a lack of political support to reestablish delivery of the ecosystem amenities lost through <span class="hlt">river</span> degradation. This paper outlines an approach for addressing these shortcomings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/misr/gallery/amazon_convergence','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/misr/gallery/amazon_convergence"><span>Amazon <span class="hlt">River</span></span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2013-04-17</p> <p>... the Rio Solimoes and the Rio Negro converge to form the Amazon <span class="hlt">River</span>. This image from the Multi-angle Imaging SpectroRadiometer (MISR) ... date:  Jul 23, 2000 Images:  Amazon <span class="hlt">River</span> location:  South America thumbnail:  ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/misr/gallery/mississippi_river_multi','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/misr/gallery/mississippi_river_multi"><span>Mississippi <span class="hlt">River</span></span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2014-05-15</p> <p>article title:  Mississippi <span class="hlt">River</span> Flooding during Spring 2001   ... 794 x 390 South TIFF: 1024 x 724 The Mississippi <span class="hlt">River</span>, from its source at Lake Itasca Minnesota to the Gulf of ... lower valley occurred in 1927 and the largest in the upper Mississippi in 1993. In April 2001 another flooding event in the upper ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2007/1047/srp/srp092/of2007-1047srp092.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2007/1047/srp/srp092/of2007-1047srp092.pdf"><span>40Ar-39Ar Age Constraints on Volcanism and Tectonism in the Terror Rift of the <span class="hlt">Ross</span> Sea, Antarctica</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p></p> <p>2007-01-01</p> <p>Volcanic sills and dikes inferred from seismic reflection profiles and geophysical studies of the <span class="hlt">Ross</span> Sea are thought to be related to the rift basins in the region, and their emplacement to be coeval with extension. However, lack of precise geochronology in the Terror Rift of the <span class="hlt">Ross</span> Sea region has left these inferred relationships poorly constrained and has hindered neotectonic studies, because of the large temporal gaps between seismic reflectors of known ages. New 40Ar/39Ar geochronology presented here for submarine volcanic rocks provides better age constraints for neotectonic interpretations within the Terror Rift. Several samples from seamounts yielded young ages between 156 ± 21 and 122 ± 26 Ka. These ages support interpretations that extension within the Terror Rift was active at least through the Pleistocene. Three evenly spaced samples from the lowermost 100 m of Franklin Island range in age from 3.28 ± 0.04 to 3.73 ± 0.05 Ma. These age determinations demonstrate that construction of a small volcanic edifice such as Franklin Island took at least several hundred thousand years, and therefore that much larger ones in the Erebus Volcanic Province are likely to have taken considerably longer than previously inferred. This warrants caution in applying a limited number of age determinations to define the absolute ages of events in the <span class="hlt">Ross</span> Sea region</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.P34A..06B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.P34A..06B"><span>Breaking Ice 2: A rift system on the <span class="hlt">Ross</span> Ice Shelf as an analog for tidal tectonics on icy moons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brunt, K. M.; Hurford, T., Jr.; Schmerr, N. C.; Sauber, J. M.; MacAyeal, D. R.</p> <p>2016-12-01</p> <p>Ice shelves are the floating regions of the polar ice sheets. Outside of the influence of the narrow region of their grounding zone, they are fully hydrostatic and strongly influenced by the ocean tides. Recent observational and modeling studies have assessed the effect of tides on ice shelves, including: the tidal influence on the ice-shelf surface height, which changes by as much as 6 to 7 m on the southern extreme of the Ronne-Filchner Ice Shelf; the tidal modulation of the ice-shelf horizontal flow velocities, which changes the mean ice-flow rate by as much as two fold on the <span class="hlt">Ross</span> Ice Shelf; and the tidal contribution to fracture and rift propagation, which eventually leads to iceberg calving. Here, we present the analysis of 16 days of continuous GPS data from a rift system near the front of the <span class="hlt">Ross</span> Ice Shelf. While the GPS sites were installed for a different scientific investigation, and not optimized to assess tidal rifting mechanics, they provide a first-order sense of the tidal evolution of the rift system. These analyses can be used as a terrestrial analog for tidal activity on icy satellites, such as Europa and Enceladus, moons of Jupiter and Saturn, respectively. Using remote sensing and modeling of the <span class="hlt">Ross</span> Ice Shelf rift system, we can investigate the geological processes observed on icy satellites and advance modeling efforts of their tidal-tectonic evolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1036239','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1036239"><span>Iron Fertilization of the Southern Ocean: Regional Simulation and Analysis of C-Sequestration in the <span class="hlt">Ross</span> Sea</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kevin Arrigo</p> <p>2012-03-13</p> <p>A modified version of the dynamic 3-dimensional mesoscale Coupled Ice, Atmosphere, and Ocean model (CIAO) of the <span class="hlt">Ross</span> Sea ecosystem has been used to simulate the impact of environmental perturbations upon primary production and biogenic CO2 uptake. The <span class="hlt">Ross</span> Sea supports two taxonomically, and spatially distinct phytoplankton populations; the haptophyte Phaeocystis antarctica and diatoms. Nutrient utilization ratios predict that P. antarctica and diatoms will be driven to nitrate and phosphate limitation, respectively. Model and field data have confirmed that the <span class="hlt">Ross</span> Sea is iron limited with only two-thirds of the macronutrients consumed by the phytoplankton by the end of the growing season. In this study, the CIAO model was improved to simulate a third macronutrient (phosphate), dissolved organic carbon, air-sea gas exchange, and the carbonate system. This enabled us to effectively model pCO2 and subsequently oceanic CO2 uptake via gas exchange, allowing investigations into the affect of alleviating iron limitation on both pCO2 and nutrient drawdown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013GeCoA.117...99L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013GeCoA.117...99L"><span>Eco-environmental implications of elemental and carbon isotope distributions in ornithogenic sediments from the <span class="hlt">Ross</span> Sea region, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Xiaodong; Nie, Yaguang; Sun, Liguang; Emslie, Steven D.</p> <p>2013-09-01</p> <p>Seabirds have substantial influence on geochemical circulation of elements, serving as a link for substance exchange between their foraging area and colonies. In this study, we investigated the elemental and carbon isotopic composition of five penguin-affected sediment profiles excavated from <span class="hlt">Ross</span> Island and Beaufort Island in the <span class="hlt">Ross</span> Sea region, Antarctica. Among the three main constituents of the sediments (including weathered bedrock, guano and algae), guano was the main source of organic matter and nutrients, causing selective enrichment of several elements in each of the sediment profiles. In the 22 measured elements, As, Cd, Cu, P, S, Se and Zn were identified as penguin bio-elements in the <span class="hlt">Ross</span> Sea region through statistical analysis and comparison with local end-member environmental media such as weathered bedrock, fresh guano and fresh algae. Carbon isotopic composition in the ornithogenic sediments showed a mixing feature of guano and algae. Using a two-member isotope mixing equation, we were able to reconstruct the historical change of guano input and algal bio-mass. Compared with research in other parts of Antarctic, Arctic, and South China Sea, we found apparent overlap of avian bio-elements including As, Cd, Cu, P, Se, and Zn. Information on the composition and behavior of bio-elements in seabird guano on a global scale, and the role that bio-vectors play in the geochemical circulation between land and sea, will facilitate future research on avian ecology and paleoclimatic reconstruction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSHE44D1542K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSHE44D1542K"><span>Environmental Drivers of Biogeochemical Variability in the Southern <span class="hlt">Ross</span> Sea: Results from a 1D Modeling Study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaufman, D. E.; Friedrichs, M. A.; Smith, W.; Hofmann, E. E.; Hemmings, J. C. P.</p> <p>2016-02-01</p> <p><span class="hlt">Ross</span> Sea phytoplankton, generally dominated by diatoms and Phaeocystis antarctica, play an essential biogeochemical role in this highly biologically productive Southern Ocean region. Although associations between these phytoplankton and environmental factors such as temperature, vertical mixing, and irradiance have been documented, the causal mechanisms among these interactions and extent to which they are modified by altered climatic conditions are poorly understood. To investigate these relationships, data from a 2012 glider deployment are analyzed in conjunction with model experiments performed using a modified version of the multi-component Model of Ecosystem Dynamics, nutrient Utilisation, Sequestration and Acidification (MEDUSA) run within the Marine Model Optimization Testbed (MarMOT), a one-dimensional data assimilative analysis framework. Specifically, MEDUSA has been adapted for the <span class="hlt">Ross</span> Sea by including both solitary and colonial forms of P. antarctica and irradiance-Fe interactions. After evaluating model performance with glider observations of chlorophyll and particulate organic carbon, scenario experiments are conducted investigating how the magnitude and phenology of spring and summer phytoplankton are likely to be modified by a future altered climate. In particular, the relative impacts of potential increased water temperatures on phytoplankton productivity will be assessed, through differences in biological rates, increased iron and light availability from melting ice, and increased stratification. Variability in phytoplankton productivity resulting from these effects of warming temperatures are analyzed individually and in combination to evaluate the relative importance of these drivers of change in the biogeochemical environment of the <span class="hlt">Ross</span> Sea.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PrOce.149...16Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PrOce.149...16Z"><span>Water mass dynamics shape <span class="hlt">Ross</span> Sea protist communities in mesopelagic and bathypelagic layers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zoccarato, Luca; Pallavicini, Alberto; Cerino, Federica; Fonda Umani, Serena; Celussi, Mauro</p> <p>2016-12-01</p> <p>Deep-sea environments host the largest pool of microbes and represent the last largely unexplored and poorly known ecosystems on Earth. The <span class="hlt">Ross</span> Sea is characterized by unique oceanographic dynamics and harbors several water masses deeply involved in cooling and ventilation of deep oceans. In this study the V9 region of the 18S rDNA was targeted and sequenced with the Ion Torrent high-throughput sequencing technology to unveil differences in protist communities (>2 μm) correlated with biogeochemical properties of the water masses. The analyzed samples were significantly different in terms of environmental parameters and community composition outlining significant structuring effects of temperature and salinity. Overall, Alveolata (especially Dinophyta), Stramenopiles and Excavata groups dominated mesopelagic and bathypelagic layers, and protist communities were shaped according to the biogeochemistry of the water masses (advection effect and mixing events). Newly-formed High Salinity Shelf Water (HSSW) was characterized by high relative abundance of phototrophic organisms that bloom at the surface during the austral summer. Oxygen-depleted Circumpolar Deep Water (CDW) showed higher abundance of Excavata, common bacterivores in deep water masses. At the shelf-break, Antarctic Bottom Water (AABW), formed by the entrainment of shelf waters in CDW, maintained the eukaryotic genetic signature typical of both parental water masses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4882557','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4882557"><span>Antimicrobial Activity of Monoramnholipids Produced by Bacterial Strains Isolated from the <span class="hlt">Ross</span> Sea (Antarctica) †</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tedesco, Pietro; Maida, Isabel; Palma Esposito, Fortunato; Tortorella, Emiliana; Subko, Karolina; Ezeofor, Chidinma Christiana; Zhang, Ying; Tabudravu, Jioji; Jaspars, Marcel; Fani, Renato; de Pascale, Donatella</p> <p>2016-01-01</p> <p>Microorganisms living in extreme environments represent a huge reservoir of novel antimicrobial compounds and possibly of novel chemical families. Antarctica is one of the most extraordinary places on Earth and exhibits many distinctive features. Antarctic microorganisms are well known producers of valuable secondary metabolites. Specifically, several Antarctic strains have been reported to inhibit opportunistic human pathogens strains belonging to Burkholderia cepacia complex (Bcc). Herein, we applied a biodiscovery pipeline for the identification of anti-Bcc compounds. Antarctic sub-sea sediments were collected from the <span class="hlt">Ross</span> Sea, and used to isolate 25 microorganisms, which were phylogenetically affiliated to three bacterial genera (Psychrobacter, Arthrobacter, and Pseudomonas) via sequencing and analysis of 16S rRNA genes. They were then subjected to a primary cell-based screening to determine their bioactivity against Bcc strains. Positive isolates were used to produce crude extracts from microbial spent culture media, to perform the secondary screening. Strain Pseudomonas BNT1 was then selected for bioassay-guided purification employing SPE and HPLC. Finally, LC-MS and NMR structurally resolved the purified bioactive compounds. With this strategy, we achieved the isolation of three rhamnolipids, two of which were new, endowed with high (MIC < 1 μg/mL) and unreported antimicrobial activity against Bcc strains. PMID:27128927</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000050208','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000050208"><span>Active and Passive Microwave Determination of the Circulation and Characteristics of Weddell and <span class="hlt">Ross</span> Sea Ice</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Drinkwater, Mark R.; Liu, Xiang</p> <p>2000-01-01</p> <p>A combination of satellite microwave data sets are used in conjunction with ECMWF (Medium Range Weather Forecasts) and NCEP (National Center for Environment Prediction) meteorological analysis fields to investigate seasonal variability in the circulation and sea-ice dynamics of the Weddell and <span class="hlt">Ross</span> Seas. Results of sea-ice tracking using SSM/I (Special Sensor Microwave Imager), Scatterometer and SAR images are combined with in-situ data derived from Argos buoys and GPS drifters to validate observed drift patterns. Seasonal 3-month climatologies of ice motion and drift speed variance illustrate the response of the sea-ice system to seasonal forcing. A melt-detection algorithm is used to track the onset of seasonal melt, and to determine the extent and duration of atmospherically-led surface melting during austral summer. Results show that wind-driven drift regulates the seasonal distribution and characteristics of sea-ice and the intensity of the cyclonic Gyre circulation in these two regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRD..121.3339C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRD..121.3339C"><span>Characteristics of the near-surface atmosphere over the <span class="hlt">Ross</span> Ice Shelf, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cassano, John J.; Nigro, Melissa A.; Lazzara, Matthew A.</p> <p>2016-04-01</p> <p>Two years of data from a 30 m instrumented tower are used to characterize the near-surface atmospheric state over the <span class="hlt">Ross</span> Ice Shelf, Antarctica. Stable stratification dominates the surface layer at this site, occurring 83% of the time. The strongest inversions occur for wind speeds less than 4 m s-1 and the inversion strength decreases rapidly as wind speed increases above 4 m s-1. In summer unstable stratification occurs 50% of the time and unstable conditions are observed in every season. A novel aspect of this work is the use of an artificial neural network pattern identification technique, known as self-organizing maps, to objectively identify characteristic potential temperature profiles that span the range of profiles present in the 2 year study period. The self-organizing map clustering technique allows the more than 100,000 observed potential temperature profiles to be represented by just 30 patterns. The pattern-averaged winds show distinct and physically consistent relationships with the potential temperature profiles. The strongest winds occur for the nearly well mixed but slightly stable patterns and the weakest winds occur for the strongest inversion patterns. The weakest wind shear over the depth of the tower occurs for slightly unstable profiles and the largest wind shear occurs for moderately strong inversions. Pattern-averaged log wind profiles are consistent with theoretical expectations. The log wind profiles exhibit a kinked profile for the strongest inversion cases indicative of decoupling of the winds between the bottom and top of the tower.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..12110157G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..12110157G"><span>Resonance vibrations of the <span class="hlt">Ross</span> Ice Shelf and observations of persistent atmospheric waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Godin, Oleg A.; Zabotin, Nikolay A.</p> <p>2016-10-01</p> <p>Recently reported lidar observations have revealed a persistent wave activity in the Antarctic middle and upper atmosphere that has no counterpart in observations at midlatitude and low-latitude locations. The unusual wave activity suggests a geographically specific source of atmospheric waves with periods of 3-10 h. Here we investigate theoretically the hypothesis that the unusual atmospheric wave activity in Antarctica is generated by the fundamental and low-order modes of vibrations of the <span class="hlt">Ross</span> Ice Shelf (RIS). Simple models are developed to describe basic physical properties of resonant vibrations of large ice shelves and their coupling to the atmosphere. Dispersion relation of the long surface waves, which propagate in the floating ice sheet and are responsible for its low-order resonances, is found to be similar to the dispersion relation of infragravity waves in the ice-free ocean. The phase speed of the surface waves and the resonant frequencies determine the periods and wave vectors of atmospheric waves that are generated by the RIS resonant oscillations. The altitude-dependent vertical wavelengths and the periods of the acoustic-gravity waves in the atmosphere are shown to be sensitive to the physical parameters of the RIS, which can be difficult to measure by other means. Predicted properties of the atmospheric waves prove to be in a remarkable agreement with the key features of the observed persistent wave activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1918348B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1918348B"><span>WAIS retreat in eastern <span class="hlt">Ross</span> Sea during Meltwater Pulse-1a</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bart, Phil; DeCesare, Matthew; McGlannan, Austin; Danielson, Matthew</p> <p>2017-04-01</p> <p>The timing of MWPs are well constrained from dated coral successions. However, the temporal linkage between ice sheet retreat and MWPs remains controversial partly due to the difficulty of generating reliable deglacial chronologies from proximal Antarctic marine basins. Here we show an exceptional set of foraminiferal radiocarbon dates produced from ice-proximal deposits in the eastern <span class="hlt">Ross</span> Sea that are well-constrained by seafloor geomorphology and core sedimentology. These radiocarbon ages demonstrate that an initial short distance retreat of ˜50 km had begun by ˜14,700 ±400 years ago, corresponding to the onset of MWP-1a. The WAIS paused for ˜3,200 years to deposit a series of Grounding Zone Wedges, or sub-aqueous terminal moraines. Ice shelf collapse at 12,400 ±300 years ago preceded a 200 km retreat of the WAIS at 11,500 ±300 years ago, i.e., at the onset of MWP-1b. These results provide conclusive evidence that the WAIS retreated during two distinct intervals of rapid sea-level rise. Please fill in your abstract text.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27032403','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27032403"><span>Description of Pseudomonas gregormendelii sp. nov., a Novel Psychrotrophic Bacterium from James <span class="hlt">Ross</span> Island, Antarctica.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kosina, Marcel; Švec, Pavel; Černohlávková, Jitka; Barták, Miloš; Snopková, Kateřina; De Vos, Paul; Sedláček, Ivo</p> <p>2016-07-01</p> <p>During the microbiological research performed within the scope of activities of Czech expeditions based at the Johann Gregor Mendel Station at James <span class="hlt">Ross</span> Island, Antarctica, two psychrotrophic gram-stain negative non-fluorescent strains CCM 8506T and CCM 8507 from soil were extensively characterized using genotypic and phenotypic methods. Initial characterization using ribotyping with HindIII restriction endonuclease and phenotyping implies that both isolates belong to a single Pseudomonas species. Sequencing of rrs, rpoB, rpoD and glnA genes of strain CCM 8506(T) confirmed affiliation of investigated strains within the genus Pseudomonas. Further investigation using automated ribotyping with EcoRI (RiboPrinter(®) Microbial Characterisation System), whole-cell protein profiling using the Agilent 2100 Bioanalyzer system, extensive biochemical testing and DNA-DNA hybridization experiments confirmed that both investigated strains are members of a single taxon which is clearly separated from all hitherto described Pseudomonas spp. Based on all findings, we describe a novel species Pseudomonas gregormendelii sp. nov. with the type strain CCM 8506(T) (=LMG 28632T).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70073506','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70073506"><span>Mapping the grounding zone of <span class="hlt">Ross</span> Ice Shelf using ICESat laser altimetry</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Brunt, Kelly M.; Fricker, Helen A.; Padman, Laurie; Scambos, Ted A.; O'Neel, Shad</p> <p>2010-01-01</p> <p>We use laser altimetry from the Ice, Cloud, and land Elevation Satellite (ICESat) to map the grounding zone (GZ) of the <span class="hlt">Ross</span> Ice Shelf, Antarctica, at 491 locations where ICESat tracks cross the grounding line (GL). Ice flexure in the GZ occurs as the ice shelf responds to short-term sea-level changes due primarily to tides. ICESat repeat-track analysis can be used to detect this region of flexure since each repeated pass is acquired at a different tidal phase; the technique provides estimates for both the landward limit of flexure and the point where the ice becomes hydrostatically balanced. We find that the ICESat-derived landward limits of tidal flexure are, in many places, offset by several km (and up to ∼60 km) from the GL mapped previously using other satellite methods. We discuss the reasons why different mapping methods lead to different GL estimates, including: instrument limitations; variability in the surface topographic structure of the GZ; and the presence of ice plains. We conclude that reliable and accurate mapping of the GL is most likely to be achieved when based on synthesis of several satellite datasets</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4650636','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4650636"><span>From warm to cold: migration of Adélie penguins within Cape Bird, <span class="hlt">Ross</span> Island</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nie, Yaguang; Sun, Liguang; Liu, Xiaodong; Emslie, Steven D.</p> <p>2015-01-01</p> <p>Due to their sensitivity to environmental change, penguins in Antarctica are widely used as bio-indicators in paleoclimatic research. On the basis of bio-element assemblages identified in four ornithogenic sediment profiles, we reconstructed the historical penguin population change at Cape Bird, <span class="hlt">Ross</span> Island, for the past 1600 years. Clear succession of penguin population peaks were observed in different profiles at about 1400 AD, which suggested a high probability of migration within this region. The succession was most obviously marked by a sand layer lasting from 1400 to 1900 AD in one of the analyzed profiles. Multiple physical/chemical parameters indicated this sand layer was not formed in a lacustrine environment, but was marine-derived. Both isostatic subsidence and frequent storms under the colder climatic condition of the Little Ice Age were presumed to have caused the abandonment of the colonies, and we believe the penguins migrated from the coastal area of mid Cape Bird northward and to higher ground as recorded in the other sediment profiles. This migration was an ecological response to global climate change and possible subsequent geological effects in Antarctica. PMID:26113152</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28236709','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28236709"><span>Microplastic in the surface waters of the <span class="hlt">Ross</span> Sea (Antarctica): Occurrence, distribution and characterization by FTIR.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cincinelli, Alessandra; Scopetani, Costanza; Chelazzi, David; Lombardini, Emilia; Martellini, Tania; Katsoyiannis, Athanasios; Fossi, Maria Cristina; Corsolini, Simonetta</p> <p>2017-05-01</p> <p>This is the first survey to investigate the occurrence and extent of microplastic (MPs) contamination in sub surface waters collected near-shore and off-shore the coastal area of the <span class="hlt">Ross</span> Sea (Antarctica). Moreover, a non-invasive method to analyze MPs, consisting in filtration after water sampling and analysis of the dried filter through Fourier Transform Infrared Spectroscopy (FTIR) 2D Imaging, using an FPA detector, was proposed. The non-invasiveness of analytical set-up reduces potential bias and allows subsequent analysis of the filter sample for determination of other classes of contaminants. MPs ranged from 0.0032 to 1.18 particle per m(3) of seawater, with a mean value of 0.17 ± 0.34 particle m(-3), showing concentrations lower than those found in the oceans worldwide. MPs included fragments (mean 71.9 ± 21.6%), fibers (mean 12.7 ± 14.3%), and others (mean 15.4 ± 12.8%). The presence of different types of MPs was confirmed by FTIR spectroscopy, with predominant abundance of polyethylene and polypropylene. The potential environmental impact arising from scientific activities, such as marine activities for scientific purposes, and from the sewage treatment plant, was also evidenced.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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