Sedimentological signatures of sub-ice-shelf circulation: An example from Vincennes Bay, East Antarctica

Two cores of Holocene sediment, collected on opposite flanks of the Vanderford Glacier in Vincennes Bay, while representing contemporaneous sedimentation, have different sediment characteristics, with a relatively lower biogenic content on the western side than on the east. These sedimentological signatures are attributed to differences in circulation patterns. Circulation involves landward flow at depth, bringing warmer ocean water into contact with the base of the glacier. This water becomes mixed with fresh meltwater and suspended glacial sediments to form a buoyant plume that rises and flows in a seaward direction under the ice shelf. The landward and seaward flows are deflected to the left in the Southern Hemisphere by the Coriolis effect and, hence, are laterally separated. This pattern explains the differences observed in sediments deposited on opposite sides of the ice shelf in front of the Vanderford Glacier and may be a common feature beneath all large-scale ice shelves

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

PCR for the detection of pathogens in neonatal early onset sepsis.

BACKGROUND: A large proportion of neonates are treated for presumed bacterial sepsis with broad spectrum antibiotics even though their blood cultures subsequently show no growth. This study aimed to investigate PCR-based methods to identify pathogens not detected by conventional culture. METHODS: Whole blood samples of 208 neonates with suspected early onset sepsis were tested using a panel of multiplexed bacterial PCRs targeting Streptococcus pneumoniae, Streptococcus agalactiae (GBS), Staphylococcus aureus, Streptococcus pyogenes (GAS), Enterobacteriaceae, Enterococcus faecalis, Enterococcus faecium, Ureaplasma parvum, Ureaplasma urealyticum, Mycoplasma hominis and Mycoplasma genitalium, a 16S rRNA gene broad-range PCR and a multiplexed PCR for Candida spp. RESULTS: Two-hundred and eight samples were processed. In five of those samples, organisms were detected by conventional culture; all of those were also identified by PCR. PCR detected bacteria in 91 (45%) of the 203 samples that did not show bacterial growth in culture. S. aureus, Enterobacteriaceae and S. pneumoniae were the most frequently detected pathogens. A higher bacterial load detected by PCR was correlated positively with the number of clinical signs at presentation. CONCLUSION: Real-time PCR has the potential to be a valuable additional tool for the diagnosis of neonatal sepsis

In an in vitro model of human tuberculosis, monocyte-microglial networks regulate matrix metalloproteinase-1 and -3 gene expression and secretion via a p38 mitogen activated protein kinase-dependent pathway.

BACKGROUND: Tuberculosis (TB) of the central nervous system (CNS) is characterized by extensive tissue inflammation, driven by molecules that cleave extracellular matrix such as matrix metalloproteinase (MMP)-1 and MMP-3. However, relatively little is known about the regulation of these MMPs in the CNS. METHODS: Using a cellular model of CNS TB, we stimulated a human microglial cell line (CHME3) with conditioned medium from Mycobacterium tuberculosis-infected primary human monocytes (CoMTb). MMP-1 and MMP-3 secretion was detected using ELISAs confirmed with casein zymography or western blotting. Key results of a phospho-array profile that detects a wide range of kinase activity were confirmed with phospho-Western blotting. Chemical inhibition (SB203580) of microglial cells allowed investigation of expression and secretion of MMP-1 and MMP-3. Finally we used promoter reporter assays employing full length and MMP-3 promoter deletion constructs. Student's t-test was used for comparison of continuous variables and multiple intervention experiments were compared by one-way ANOVA with Tukey's correction for multiple pairwise comparisons. RESULTS: CoMTb up-regulated microglial MMP-1 and MMP-3 secretion in a dose- and time-dependent manner. The phospho-array profiling showed that the major increase in kinase activity due to CoMTb stimulation was in p38 mitogen activated protein kinase (MAPK), principally the α and γ subunits. p38 phosphorylation was detected at 15 minutes, with a second peak of activity at 120 minutes. High basal extracellular signal-regulated kinase activity was further increased by CoMTb. Secretion and expression of MMP-1 and MMP-3 were both p38 dependent. CoMTb stimulation of full length and MMP-3 promoter deletion constructs demonstrated up-regulation of activity in the wild type but a suppression site between -2183 and -1612 bp. CONCLUSIONS: Monocyte-microglial network-dependent MMP-1 and MMP-3 gene expression and secretion are dependent upon p38 MAPK in tuberculosis. p38 is therefore a potential target for adjuvant therapy in CNS TB

Acupuncture Point Localization Varies Among Acupuncturists

Background: Studies assessing the point-specific effect of acupuncture or the characteristics of acupuncture points (APs) tend to yield inconclusive results. In order to identify a possible confounding factor, we aimed to examine the variability in AP localization by means of a survey. Material and Methods: Attendees of the 14th ICMART (International Council of Medical Acupuncture and Related Techniques) congress as well as DAGfA (German Medical Society of Acupuncture) lecturers and students were asked to locate and mark the APs LI 10 and TH 5 on a research assistant's arm. Identified points were transferred into a coordinate system, and the respective bivariate distribution function was calculated. Additionally, participants filled out a questionnaire about their acupuncture education and experience, the acupuncture style and point localization techniques used most frequently, and their estimation of the size of an AP. Results: The areas of the ellipses, theoretically containing 95% of AP localizations, varied between 44.49 and 5.18 cm(2). The largest distance between 2 identified points was 8.45 cm for LI 10 and 5.3 cm for TH 5. Apart from being trained at the same school, no other factor could be identified that determined the variability in AP localization. Conclusion: Our results indicate that congruity of AP localization among experienced acupuncturists might be low. Although there are some limitations to our results, this possible bias should be taken into account when conducting acupuncture trials and interpreting results of previous acupuncture studies

Framing the Value of Clinical and Field Education

Community/university partnerships play a critical role in higher education. Community-based research, service learning, guest lectures, internships, and a host of other activities illustrate the shared opportunities for students, educators, practitioners, employers, and consumers, as communities and institutions collaborate to educate the future workforce and develop an informed and engaged citizenry. Across the spectrum of health and professional disciplines, real world learning through community-based clinical/field education1 is essential to prepare practice-ready graduates. At St. Catherine University, for example, students complete over 7,000 clinical/field placements annually across multiple degrees and disciplines (see Appendix B). Without community/ university partnerships, our universities would not be able to provide high quality learning experiences and educate graduates who are both qualified and competitive in the workforce. Yet the long-standing model of clinical/field education is faced with pressures and competing demands. While universities strive to increase enrollment and meet rising competition and changing accreditation standards, providers face industry and regulatory reform, economic downturns, reduced funding and reimbursement, productivity demands, a retiring workforce, and a host of other pressures. This paper is intended to strengthen community/university partnerships by articulating the value that can come from clinical/field education. The authors of this paper serve as clinical/field educators for the Henrietta Schmoll School of Health at St. Catherine University and the School of Social Work at St. Catherine University - University of St. Thomas. We draw from our own experience, conversations with clinical and fieldwork partners, faculty and students, and existing literature to outline this complex issue. The goal of this paper is to provide information, a conceptual framework, and language that can inform stakeholders and foster dialogue as we work collaboratively to address the opportunities and challenges of workforce development

Impact of vertical atmospheric structure on an atypical fire in a mountain valley

Wildfires are not only a natural part of many ecosystems, but they can also have disastrous consequences for humans, including in Australia. Rugged terrain adds to the difficulty of predicting fire behavior and fire spread, as fires often propagate contrary to expectations. Even though fire models generally incorporate weather, fuels, and topography, which are important factors affecting fire behavior, they usually only consider the surface wind; however, the more elevated winds should also be accounted for, in addition to surface winds, when predicting fire spread in rugged terrain because valley winds are often dynamically altered by the interaction of a layered atmosphere and the topography. Here, fire spread in rugged terrain was examined in a case study of the Riveaux Road Fire, which was ignited by multiple lightning strikes in January 2019 in southern Tasmania, Australia and burnt approximately 637.19 km2. Firstly, the number of conducive wind structures, which are defined as the combination of wind and temperature layers likely to result in enhanced surface wind, were counted by examining the vertical wind structure of the atmosphere, and the potential for above-surface winds to affect fire propagation was identified. Then, the multiple fire propagations were simulated using a new fire simulator (Prototype 2) motivated by the draft specification of the forthcoming new fire danger rating system, the Australian Fire Danger Rating System (AFDRS). Simulations were performed with one experiment group utilizing wind fields that included upper-air interactions, and two control groups that utilized downscaled wind from a model that only incorporated surface winds, to identify the impact of upper air interactions. Consequently, a detailed analysis showed that more conducive structures were commonly observed in the rugged terrain than in the other topography. In addition, the simulation of the experiment group performed better in predicting fire spread than those of the control groups in rugged terrain. In contrast, the control groups based on the downscaled surface wind model performed well in less rugged terrain. These results suggest that not only surface winds but also the higher altitude winds above the surface are required to be considered, especially in rugged terrain

Should Research Ethics Encourage the Production of Cost-Effective Interventions?

This project considers whether and how research ethics can contribute to the provision of cost-effective medical interventions. Clinical research ethics represents an underexplored context for the promotion of cost-effectiveness. In particular, although scholars have recently argued that research on less-expensive, less-effective interventions can be ethical, there has been little or no discussion of whether ethical considerations justify curtailing research on more expensive, more effective interventions. Yet considering cost-effectiveness at the research stage can help ensure that scarce resources such as tissue samples or limited subject popula- tions are employed where they do the most good; can support parallel efforts by providers and insurers to promote cost-effectiveness; and can ensure that research has social value and benefits subjects. I discuss and rebut potential objections to the consideration of cost-effectiveness in research, including the difficulty of predicting effectiveness and cost at the research stage, concerns about limitations in cost-effectiveness analysis, and worries about overly limiting researchers’ freedom. I then consider the advantages and disadvantages of having certain participants in the research enterprise, including IRBs, advisory committees, sponsors, investigators, and subjects, consider cost-effectiveness. The project concludes by qualifiedly endorsing the consideration of cost-effectiveness at the research stage. While incorporating cost-effectiveness considerations into the ethical evaluation of human subjects research will not on its own ensure that the health care system realizes cost-effectiveness goals, doing so nonetheless represents an important part of a broader effort to control rising medical costs