Patterns of glacial erosion and deposition in Prydz Bay and the past behaviour of the Lambert Glacier

Styles of glacial sedimentation and erosion in Prydz Bay respond to glacial and interglacial cycles and fall into three zones; an inner zone of net erosion, a middle zone of subglacially eroded and deformed transitional glacial marine deposits and an outer zone of subglacial till deposition and shelf progradation. The inner zone is the region of maximum basal shear stress and inner-shelf deep formation by enhanced erosion in areas where tributary glaciers converge with the extended Lambert Glacier. The middle zone is underlain by sediments deposited near the ice-grounding zone during retreat, both as blanket like deposits and as grounding-line moraines. This material is then deformed into elongate subglacial bedforms (megaflures or drumlins), a process that probably involves some erosion. Deforming subglacial bed conditions extend to the shelf edge within a valley crossing the shelf on the western side of Prydz Bay. The outer zone is a zone of net deposition of compact subglacial till and prograding continental slope deposits formed during full glacial conditions and glacial marine sediment formed during ice retreat. The inferred build up of ice on the Ingrid Christensen Coast may have been responsible for the development of the western ice stream that flowed in Prydz Channel. The geometry of seismic sequences in Prydz Channel suggests that this ice stream and its associated trough mouth fan developed after a major episode of shelf and slope erosion during the Pliocene

Late Quaternary history of sedimentation on the Mac. Robertson shelf, East Antarctica: problems with 14C-dating of marine sediment cores

Stratigraphic information concerning the retreat of the Antarctic ice sheet from the continental shelf after the Last Glacial Maximum is reviewed and compared with new results from a shelf valley off Mac. Robertson Land, East Antarctica. Radiocarbon dates and detailed lithostratigraphic logs indicate that the onset of open-marine conditions over shallow shelfbanks (<200 m water depth) was achieved prior to 7000 yr BP and over deep (~l 000 m) middle to oliter shelf valleys, open-marine conditions were achieved prior to 5400 yr BP. Radiocarbon dating of bulk-organic carbon in some diatom oozes by the AMS method demonstrates problems of contamination. Jurassic pollen, spores and organic matter have been eroded and incorporated into Holocene diatom ooze, causing anomalously old 14C dates (e.g. one surface age of 7084 ± 86 yr BP was determined). This problem may arise at other locations around East Antarctica where older strata outcrop on the seafloor

A review of the Cenozoic stratigraphy and glacial history of the Lambert Graben - Prydz Bay region, East Antarctica

The Cenozoic glacial history of East Antarctica is recorded in part by the stratigraphy of the Prydz Bay - Lambert Graben region. The glacigene strata and associated erosion surfaces record at least 10 intervals of glacial advance (with accompanying erosion and sediment compaction), and more than 17 intervals of glacial retreat (enabling open marine deposition in Prydz Bay and the Lambert Graben). The number of glacial advances and retreats is considerably less than would be expected from Milankovitch frequencies due to the incomplete stratigraphic record. Large advances of the Lambert Glacier caused progradation of the continental shelf edge. At times of extreme glacial retreat, marine conditions reached &gt; 450 km inland from the modern ice shelf edge. This review presents a partial reconstruction of Cenozoic glacial extent within Prydz Bay and the Lambert Graben that can be compared to eustatic sea-level records from the southern Australian continental margin

Silicon photonics-based laser Doppler vibrometer array for carotid-femoral pulse wave velocity (PWV) measurement

Pulse wave velocity (PWV) is a reference measure for aortic stiffness, itself an important biomarker of cardiovascular risk. To enable low-cost and easy-to-use PWV measurement devices that can be used in routine clinical practice, we have designed several handheld PWV sensors using miniaturized laser Doppler vibrometer (LDV) arrays in a silicon photonics platform. The LDV-based PWV sensor design and the signal processing protocol to obtain pulse transit time (PTT) and carotid-femoral PWV in a feasibility study in humans, are described in this paper. Compared with a commercial reference PWV measurement system, measuring arterial pressure waveforms by applanation tonometry, LDV-based displacement signals resulted in more complex signals. However, we have shown that it is possible to identify reliable fiducial points for PTT calculation using the maximum of the 2nd derivative algorithm in LDV-based signals, comparable to those obtained by the reference technique, applanation tonometry. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

Using Abbreviated Injury Scale (AIS) codes to classify Computed Tomography (CT) features in the Marshall System

<p>Abstract</p> <p>Background</p> <p>The purpose of Abbreviated Injury Scale (AIS) is to code various types of Traumatic Brain Injuries (TBI) based on their anatomical location and severity. The Marshall CT Classification is used to identify those subgroups of brain injured patients at higher risk of deterioration or mortality. The purpose of this study is to determine whether and how AIS coding can be translated to the Marshall Classification</p> <p>Methods</p> <p>Initially, a Marshall Class was allocated to each AIS code through cross-tabulation. This was agreed upon through several discussion meetings with experts from both fields (clinicians and AIS coders). Furthermore, in order to make this translation possible, some necessary assumptions with regards to coding and classification of mass lesions and brain swelling were essential which were all approved and made explicit.</p> <p>Results</p> <p>The proposed method involves two stages: firstly to determine all possible Marshall Classes which a given patient can attract based on allocated AIS codes; via cross-tabulation and secondly to assign one Marshall Class to each patient through an algorithm.</p> <p>Conclusion</p> <p>This method can be easily programmed in computer softwares and it would enable future important TBI research programs using trauma registry data.</p

Laparoscopic adjustable gastric band in an obese unrelated living donor prior to kidney transplantation: a case report

Introduction. Obese living donors who undergo donor nephrectomy have higher rates of intra-operative and post-operative complications. Many centres exclude obese donors from living donor transplant programs. Diet, exercise and medication are often ineffective weight loss interventions for donors, hence bariatric surgery should be considered. Case presentation. We report the case of a 53-year-old Caucasian woman who underwent laparoscopically adjustable gastric banding. The procedure enabled her to lose sufficient weight to gain eligibility for kidney donation. After losing weight, she had an uncomplicated laparoscopic donor nephrectomy surgery, and the recipient underwent successful kidney transplantation. Conclusion. Laparoscopically adjustable gastric banding should be considered for obese potential living kidney donors whenever transplantation units restrict access to donor nephrectomy based on the increased surgical risk for donors