27,066 research outputs found
Evidences of carbonate preservation on the outer continental slope in the Western Ross Sea (Hallett Ridge and Central Basin, Antarctica)
No full textLate Quaternary Antarctic Ice Sheet (AIS) changes can be investigated by analyzing marine sediments (gravity and box cores) collected on the continental shelves and along the continental margins of Antarctica. These sites are strongly influenced by the ice sheet/shelf sediment drainage and inflow/outflow of polar water masses. In this respect, the continental slope of the Western Ross Sea (WRS) is still poorly studied, in particular its history is affected by uncertainties due to the scarcity of well-preserved calcareous foraminifera preventing the production of reliable age models.
We present the results of a study made on one gravity core (KI13-C2; Melis et al., 2021) and three box-cores (KI13-bc2, bc3 and bc4; Torricella et al., 2021) located on the Hallett Ridge and in the Central Basin where the presence of carbonate-rich intervals offers the opportunity, to time-reconstruct the AIS evolving changes since the Marine Isotopic Stage (MIS) 2. These intervals correlated with other carbonate layers identified in cores collected along the WRS continental slope provide important insights about a large-scale break-up of the ice shelf/sea ice system.
This study has been conducted in the framework of the STREAM Project (Late Quaternary evolution of the ocean-ice sheet interactions: the record from the Ross Sea continental margin, Antarctica; period 2019-2021), funded by the Italian Ministry of Foreign Affairs and International Cooperation and the National Research Foundation of Korea, and thanks to a grant approved by the Department of Mathematics and Geoscience, University of Trieste.
Bibliographic references
Melis R., Capotondi L., Torricella F., Ferretti P., Geniram A., Hong J.K., Kuhn G., Khim B.-K., Kim S., Malinverno E., Yoo K.C. and Colizza E. (2021) - Last Glacial Maximum to Holocene: paleoceanography of the northwestern Ross Sea inferred from sediment core geochemistry and micropaleontology at Hallett Ridge. J. of Micropal., 40, 15-35.
Torricella F., Melis R., Malinverno E., Fontolan G., Bussi M., Capotondi L., Del Carlo P., Di Roberto A., Geniram A., Kuhn G., Khim B.-K., Morigi C., Scateni B. and Colizza E. (2021) – Environmental and Oceanographic Conditions at the Continental Margin of the Central Basin, Northwestern Ross Sea (Antarctica) Since the Last Glacial Maximum. Geosciences, 11, 155
Multiproxy quantitative paleoceanographic dataset from late Quaternary marine sediment archives in the western Ross Sea (Antarctica)
No full textThe past ice sheet dynamics and the timing of retreat events in the paleo-record in the Ross Sea is an issue still few understood. In order to contribute to this topic, we provide a multiproxy data from marine sediment archives (cores and box cores) collected in three sites in the Central Basin (Western Ross Sea, Antarctica). Each site recorded different environments, affected by different oceanographic conditions and sedimentary regime. This makes the three investigated sediment cores and box cores unique and useful for comparison with other studied cores collected in the same basin. The data set includes physical (paleomagnetism, grain size and petrography), chemical, micropaleontological (diatom, foraminifera and silicoflagellate assemblages) analyses and cryptotephra characterization increasing the information already reported in literature. The importance of this dataset is related to a multi-disciplinary approach in a site, the Central Basin, few investigated which represents a key area to connect the Southern Ocean and the Ross Sea. © 2024 The Author
K-Ar ages from Oates Coast sector (Pacific margin) and Terra Nova Bay sector (Ross Sea), Antarctica (Table 4.6-1)
No full textK-Ar ages from Oates Coast sector (Pacific margin) and Terra Nova Bay sector (Ross Sea), Antarctica (Table 4.6-1
Comparative Ross Risk Aversion in the Presence of Mean Dependent Risks
No full textThis paper studies comparative risk aversion between risk averse agents in the presence of a background risk. Although the literature covers this question extensively, our contribution differs from most of the literature in two respects. First, background risk does not need to be additive or multiplicative. Second, the two risks are not necessary mean independent, and may be conditional expectation increasing or decreasing. We show that our order of cross Ross risk aversion is equivalent to the order of partial risk premium, while our index of decreasing cross Ross risk aversion is equivalent to decreasing partial risk premium. These results generalize the comparative risk aversion model developed by Ross (1981) for mean independent risks. Finally, we show that decreasing cross Ross risk aversion gives rise to the utility function family belonging to the class of n-switch utility functions.Comparative cross Ross risk aversion, Dependent background risk, Partial risk premium, Decreasing cross Ross risk aversion, n-switch utility function
Education Quality Matters:Trends and Challenges
No full textBritish Computer Society INSPIRE conference proceedingseditors K Phalp. V Katos, S Meacham, M Ross, G Staples, J Uhomoibhi <br/
CS Ross
No full textResearch School of Social Sciences - Research Scholars - S. Matsuura, D. Hindley, J. D. Playford, K. G. Jones, G. A. Waterson, Dr. R. R. Brown, Dr. Prgybylski, Dr. D. A. Low, Dr. W. E. Salter, S. R. Adke, Mr. G. Docker, A. R. Barcan, Dr. J. C. Harsanyi, Dr. K. H. Burley, Miss Ann Myers, G. P. King, J. Stockwin, Mr. R. G. Boyd, Dr. H. O. Pappe, Dr. J. A. Barnard, R. J. Lawrence, K. G. Pont, J. Caldwell, N. G. Cain, D. W. Dockrill, C. S. Ross, Abraham Harari, I. Fairbanks, Mr. G. Pursell, F. L. Jones, M. Wu, David B. Heron, D. K. Singh, H. Yuan T'ien, Owen Michael Roe, F. S. Henr
Chemical threats for the sentinel Pygoscelis adeliae from the Ross Sea (Antarctica): Occurrence and levels of persistent organic pollutants (POPs), perfluoroalkyl substances (PFAS) and mercury within the largest marine protected area worldwide
No full textThe Ross Sea Marine Protected Area (RS-MPA) hosts endemic species that have to cope with multiple threats, including chemical contamination. Adèlie penguin is considered a good sentinel species for monitoring pollutants. Here, 23 unhatched eggs, collected from three colonies along the Ross Sea coasts, were analysed to provide updated results on legacy pollutants and establish a baseline for newer ones. Average sum of polychlorinated biphenyls (∑PCBs) at the three colonies ranged 20.9–24.3 ng/g lipid weight (lw) and included PCBs IUPAC nos. 28, 118, 153, 138, 180. PCBs were dominated by hexachlorinated congeners as previously reported. Hexachlorobenzene (HCB) and p,p’-dichlorodiphenyldichloroethylene (p,p’-DDE) ranged between 134 and 166 and 181–228 ng/g lw, respectively. Overall, ∑PCBs was exceeded by pesticides, contrary to previous studies from the Ross Sea. Sum of polybrominated diphenyl ethers (∑PBDEs) ranged between 0.90 and 1.18 ng/g lw and consisted of BDE-47 (that prevailed as expected, representing 60–80 % of the ∑PBDEs) and BDE-85. Sum of perfluoroalkyl substances (∑PFAS) ranged from 1.04 to 1.53 ng/g wet weight and comprised five long-chain perfluorinated carboxylic acids (PFCAs), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS) and perfluorooctanoic acid (PFOA); perfluorooctane sulfonamide (PFOSA) was also detected. The PFAS profile was dominated by PFCAs as already observed in Arctic seabirds. Mercury ranged from 0.07 to 0.15 mg/kg dry weight similarly to previous studies. Legacy pollutants confirmed their ongoing presence in Antarctic biota and their levels seemed mostly in line with the past, but with minor variations in some cases, likely due to continued input or release from past reservoirs. PFAS were reported for the first time in penguins from the Ross Sea, highlighting their ubiquity. Although further studies would be useful to increase the sample size and accordingly improve our knowledge on spatial and temporal trends, this study provides interesting data for future monitoring programs within the RS-MPA that will be crucial to test its effectiveness against human impacts
Recommended from our members
The leadership of Ross O. Swimmer, 1975-1985 : a case study of a modern Cherokee principal chief
No full texttextThe following study examined leadership characteristics of a modern leader of the Cherokee Nation, Ross O. Swimmer, during his three elections as Principal Chief, 1975-1985. Few Western scholars paid attention to the Cherokee Tribe after the break-up of institutions legislated by the federal Indian policy of Allotment. The position of the government was, the Cherokee Tribe no longer existed. For almost seventy years, no form of Cherokee leadership was visible; no Cherokee government existed. Federal Indian policy changed again, allowing tribes to elect their own leaders. This study began filling in gaps of missing information on modern Cherokee leadership by examining Swimmer’s leadership characteristics. The study attempted to add to the body of leadership knowledge by mining minds and memories, searching for the meaning of leadership from a modern Cherokee perspective. The three questions guiding the study were: what were the leadership characteristics of Principal Chief Ross O. Swimmer; to what extent did these leadership characteristics reflect traditional Cherokee leadership characteristics; and from a tribal perspective, did these make a difference, and to what extent? The data indicate seven Swimmer leadership characteristics: Visionary, Goal Oriented, Bureaucratic, Top-Down, Authoritarian, Delegator, and Communicator. There was inconsistency with Swimmer’s use of traditional leadership practices. Swimmer used a combination of traditional Cherokee, traditional Native American, and Anglo-European-American leadership characteristics during his three terms as Principal Chief of the Cherokee Nation. Two possible explanations for Swimmer’s blending leadership characteristics from varying models were suggested. First, given his bi-cultural heritage, Swimmer could navigate back and forth between the mainstream White culture and the traditional Cherokee culture, to pick and choose various types of leadership characteristics. Second, adaptability has always been a unique characteristic of the Cherokee people. Cherokee leaders frequently applied the feature of borrowing from White culture in order to adapt and survive. Swimmer accomplished many of his goals for the Cherokee people and set the Nation on a path of growth and stability. His methods were not without criticism from traditional Cherokees. However, Swimmer built the foundation for a corporate government that instilled pride in the Cherokee people and provided opportunity for self-sufficiency.Educational Administratio
Ross syndrome: a case report
No full textRoss syndrome is a rare partial dysautonomic syndrome of unknown aetiology, characterized by segmental hypo/ anhidrosis associated with Holmes-Adie syndrome (tonic pupil and hypo/areflexia). The hypohydrosis or anhydrosis is patchy initially, later it becomes segmental or diffuse. This is due to affection of postganglionic cholinergic parasympathetic and sympathetic fibers involvement. There are a very few cases (approximately 50) have been reported in the literature since its original description. Author report a 22 years old male with classical features of Ross syndrome
Composition and distribution of the peracarid crustacean fauna along a latitudinal transect off Victoria Land (Ross Sea, Antarctica) with special emphasis on the Cumacea
No full textThe following study was the first to describe composition and structure of the peracarid fauna systematically along a latitudinal transect off Victoria Land (Ross Sea, Antarctica). During the 19th Antarctic expedition of the Italian research vessel “Italica” in February 2004, macrobenthic samples were collected by means of a Rauschert dredge with a mesh size of 500 m at depths between 85 and 515 m. The composition of peracarid crustaceans, especially Cumacea was investigated. Peracarida contributed 63% to the total abundance of the fauna. The peracarid samples were dominated by amphipods (66%), whereas cumaceans were represented with 7%. Previously, only 13 cumacean species were known, now the number of species recorded from the Ross Sea increased to 34. Thus, the cumacean fauna of the Ross Sea, which was regarded as the poorest in terms of species richness, has to be considered as equivalent to that of other high Antarctic areas. Most important cumacean families concerning abundance and species richness were Leuconidae, Nannastacidae, and Diastylidae. Cumacean diversity was lowest at the northernmost area (Cape Adare). At the area off Coulman Island, which is characterized by muddy sediment, diversity was highest. Diversity and species number were higher at the deeper stations and abundance increased with latitude. A review of the bathymetric distribution of the Cumacea from the Ross Sea reveals that most species distribute across the Antarctic continental shelf and slope. So far, only few deep-sea records justify the assumption of a shallow-water–deep-sea relationship in some species of Ross Sea Cumacea, which is discussed from an evolutionary point of view
- …
