Cloud computing and the humanities: National eResearch Collaboration Tools and Resources

The NeCTAR Research Cloud provides free cloud computing for Australian Researchers. This poster describes this important piece of new infrastructure, and why those in the digital humanities might be interested.Australian Academy of the Humanities; the ANU College of Arts and Social Science

The Efficacy of Tele-practice on Expressive Language Outcomes for Adults with Aphasia

Access to skilled speech and language intervention can be difficult for individuals residing in rural areas as well as for individuals with complex health and mobility issues. Telehealth (including therapy and rehabilitation) can provide effective services in the context of one’s home, allowing clinicians to reach a wider population of individuals. Purpose: To determine whether tele-practice service delivery produces positive expressive language outcomes that are comparable to direct service delivery for adults with aphasia. Method: A variety of databases were searched utilizing systematic inclusionary and exclusionary criteria. Research focused on adults over the age of 18 with a formal diagnosis of aphasia who engaged in telehealth intervention. Various research designs were identified and analyzed. Identified articles included a total of 235 participants. Results: The identified studies supported the implementation of tele-practice as a means of providing individuals with aphasia access to services that produce positive expressive language outcomes. Several studies indicated that tele-practice produces similar outcomes when compared to traditional direct therapy. Several studies also included qualitative data regarding patient satisfaction and quality of life, much of which produced positive outcomes. Conclusion: The chosen studies were found to largely support the inclusion of tele-practice as an effective option for producing positive expressive language outcomes for individuals with aphasia. Potential limitations include variability in treatment times and programs, assessment tools used, clinical training of individuals providing treatment, small sample sizes, and variable patient characteristics. Future research should focus on implementing research designs using larger numbers of individuals to increase generalizability.https://scholarworks.uvm.edu/csdms/1003/thumbnail.jp

Robust radiocarbon dating of wood samples by high-sensitivity liquid scintillation spectroscopy in the 50–70 kyr age range

Although high-sensitivity liquid scintillation (LS) spectroscopy is theoretically capable of producing finite radiocarbon ages in the 50,000- to 70,000-yr range, there is little evidence in the literature that meaningful dates in this time period have been obtained. The pressing need to undertake calibration beyond 26 kyr has resulted in the regular publication of ¹⁴C results in excess of 50 kyr, yet very little effort has been made to demonstrate their accuracy or precision. There is a paucity of systematic studies of the techniques required to produce reliable dates close to background and the methods needed to assess contamination from either in situ sources or laboratory handling and processing. We have studied the requirements for producing accurate and reliable dates beyond 50 kyr. Laboratory procedures include optimization of LS spectrometers to obtain low and stable non-¹⁴C background count rates, use of low-background counting vials, large benzene volumes, long counting times, and preconditioning of vacuum lines. We also discuss the need for multiple analyses of a suitable material containing no original ¹⁴C (background blank) and the application of an appropriate statistical model to compensate for variability in background contamination beyond counting statistics. Accurate and reproducible finite ages >60 kyr are indeed possible by high-sensitivity LS spectroscopy, but require corroborating background blank data to be defensible

Amplified erosion above waterfalls and oversteepened bedrock reaches

None of the conventional bedrock erosion laws can predict incision immediately upslope of a waterfall lip where the flow is accelerating toward a freefall. Considering the expected increase in flow velocity and shear stress at the lip of a waterfall, we determine erosion amplification at a waterfall lip as [equation], where [equation] is the erosion rate at the upstream end of the flow acceleration zone above a waterfall, Fr is the Froude number at this setting, and n ranges between 0.5–1.7. This amplification expression suggests that erosion at the lip could be as much as 2–5 times higher relative to erosion at a normal setting with identical hydraulic geometry. Utilizing this erosion amplification expression in numerical simulations, we demonstrate its impact on reach-scale morphology above waterfalls. Amplified erosion at the lip of a waterfall can trigger the formation of an oversteepened reach whose length is longer than the flow acceleration zone, provided incision wave velocity (Vi) at the upstream edge of the flow acceleration zone is higher than the retreat velocity of the waterfall face. Such an oversteepened reach is expected to be more pronounced when Vi increases with increasing slope. The simulations also suggest that oversteepening can eventually lead to steady state gradients adjacent to a waterfall lip provided Vi decreases with increasing slope. Flow acceleration above waterfalls can thus account, at least partially, for prevalent oversteepened bedrock reaches above waterfalls. Using the cosmogenic isotope Cl-36, we demonstrate that incision wave velocity upstream of a waterfall at the Dead Sea western escarpment is probably high enough for freefall-induced oversteepening to be feasible

A Churn for the Better: Localizing Censorship using Network-level Path Churn and Network Tomography

Recent years have seen the Internet become a key vehicle for citizens around the globe to express political opinions and organize protests. This fact has not gone unnoticed, with countries around the world repurposing network management tools (e.g., URL filtering products) and protocols (e.g., BGP, DNS) for censorship. However, repurposing these products can have unintended international impact, which we refer to as "censorship leakage". While there have been anecdotal reports of censorship leakage, there has yet to be a systematic study of censorship leakage at a global scale. In this paper, we combine a global censorship measurement platform (ICLab) with a general-purpose technique -- boolean network tomography -- to identify which AS on a network path is performing censorship. At a high-level, our approach exploits BGP churn to narrow down the set of potential censoring ASes by over 95%. We exactly identify 65 censoring ASes and find that the anomalies introduced by 24 of the 65 censoring ASes have an impact on users located in regions outside the jurisdiction of the censoring AS, resulting in the leaking of regional censorship policies