Contemporary Guarani Shamanisms: “Traditional Medicine” and Discourses of Native Identity in Brazil

The psychoactive substance known as ayahuasca has long been identified with Amazonian shamanism and traditional medicine. Over the last two decades its use has spread outside this region to urban populations in different parts of the world. This paper examines the adoption of the ritual use of the beverage by the Guarani Indians along the southern coast of Brazil. We argue that this process is related to the growing politics of identity of Brazilian indigenous peoples as well as to public policies that promote cultural diversity. In the case analyzed here, the adoption of ayahuasca is articulated with an ongoing cultural revitalization in activities related to shamanism, health and education and with the specific desires and actions of the leading family in one Guarani village

A high-wavenumber boundary-element method for an acoustic scattering problem

In this paper we show stability and convergence for a novel Galerkin boundary element method approach to the impedance boundary value problem for the Helmholtz equation in a half-plane with piecewise constant boundary data. This problem models, for example, outdoor sound propagation over inhomogeneous flat terrain. To achieve a good approximation with a relatively low number of degrees of freedom we employ a graded mesh with smaller elements adjacent to discontinuities in impedance, and a special set of basis functions for the Galerkin method so that, on each element, the approximation space consists of polynomials (of degree $\nu$) multiplied by traces of plane waves on the boundary. In the case where the impedance is constant outside an interval $[a,b]$, which only requires the discretization of $[a,b]$, we show theoretically and experimentally that the $L_2$ error in computing the acoustic field on $[a,b]$ is ${\cal O}(\log^{\nu+3/2}|k(b-a)| M^{-(\nu+1)})$, where $M$ is the number of degrees of freedom and $k$ is the wavenumber. This indicates that the proposed method is especially commendable for large intervals or a high wavenumber. In a final section we sketch how the same methodology extends to more general scattering problems

Assessment of the ergogenic effect of caffeine supplementation on mood, anticipation timing, and muscular strength in older adults

The effect of caffeine to promote improvements in mood, cognition, and exercise performance has been well established in young and athletic adults. However, little is known about whether such nutritional ergogenic aids are effective in enhancing psychological well-being, physiological or cognitive performance in older adults. This study assesses the ergogenic effect of caffeine on mood, perceptual-motor coupling, and muscular strength in an older human population. Following a familiarization session, 12 apparently healthy volunteers (nine females and three males; 69 ± 6 years) completed two laboratory visits. "Pre ingestion" trials of mood state Brunel Mood State Inventory (BRUMS) and coincidence anticipation performance (Bassin anticipation timer) at slow (3 mph) and fast (8 mph) stimulus speeds were completed on both visits. Using a randomized, double-blind, cross-over design, participants consumed either caffeine (3 mg/kg body mass) or a placebo. Sixty minutes postingestion participants repeated the trials before completing a set of 10 consecutive repetitions of maximal knee extension using isokinetic dynamometry. Rating of perceived exertion (RPE) was assessed following the fifth and final repetition. Caffeine ingestion significantly improved mood state scores for vigor by 17% (P = 0.009) and reduced absolute error by 35% (P = 0.045) during coincidence anticipation assessment at 8 mph compared to placebo. There were no other significant effects. Caffeine ingestion failed to augment maximal voluntary contraction of the knee extensors and RPE did not prove to be significantly different to from placebo (P > 0.33 in each case). Acute caffeine ingestion may not be an effective ergogenic aid for improving muscular strength in older adults but could possibly be used as a nutrition supplement for enhancing mood and improving cognitive performance in daily living tasks where interceptive timing skills are required

Long-term perspectives on terrestrial and aquatic carbon cycling from palaeolimnology

Lakes are active processors and collectors of carbon (C) and thus recognized as quantitatively important within the terrestrial C cycle. Better integration of palaeolimnology (lake sediment core analyses) with limnological C budgeting approaches has the potential to enhance understanding of lacustrine C processing and sequestration. Palaeolimnology simultaneously assimilates materials from across lake habitats, terrestrial watersheds, and airsheds to provide a uniquely broad overview of the terrestrial-atmospheric-aquatic linkages across different spatial scales. The examination of past changes over decadal–millennial timescales via palaeolimnology can inform understanding and prediction of future changes in C cycling. With a particular, but not exclusive, focus on northern latitudes we examine the methodological approaches of palaeolimnology, focusing on how relatively standard and well-tested techniques might be applied to address questions of relevance to the C cycle. We consider how palaeolimnology, limnology, and sedimentation studies might be linked to provide more quantitative and holistic estimates of lake C cycling and budgets. Finally, we use palaeolimnological examples to consider how changes such as terrestrial vegetation shifts, permafrost thaw, the formation of new lakes and reservoirs, hydrological modification of inorganic C processing, land use change, soil erosion and disruption to global nitrogen and phosphorus cycles might influence lake C cycling

Boston University Medical Center: Perspectives on Health Policy

Report of a symposium held at the Boston University Medical Center

Optical diagnostics in near-field blast measurements

The understanding of structural and material response to air-blast loading is a necessary prerequisite to the development of effective blast protection and mitigation systems. Computational tools have advanced significantly, enabling extensive simulations of the loading and ensuing structural response that occur as the result of an explosive detonation. Experimental techniques, however, have lagged behind in providing robust, high fidelity measurements regarding the transient response and spatial distribution of specific impulse across a structure. This article discusses recent advances in these techniques at the University of Sheffield and describes the results that can be obtained. It details proof of concept testing via a bilateral collaboration between the UK and South Africa involving single-blind experimentation using high-speed imaging, digital image correlation and comparisons with results from near-field blast experiments performed at the University of Sheffield CoBL facility. Secondly, it describes some of the continued developments since the success of those early trials, resulting in a new optical diagnostics for blast capability at the University of Sheffield. This article demonstrates the usefulness of improved diagnostics and techniques in blast experiments and shows the efficacy and versatility of high-speed imaging and DIC for determining impulse profiles and transient structural behaviour. Ultra-high speed imaging is also shown to be a useful tool for visualising detonation fronts in explosive charges and the expanding fireball

Genetic Improvement @ ICSE 2020

Following Prof. Mark Harman of Facebook's keynote and formal presentations (which are recorded in the proceedings) there was a wide ranging discussion at the eighth international Genetic Improvement workshop, GI-2020 @ ICSE (held as part of the 42nd ACM/IEEE International Conference on Software Engineering on Friday 3rd July 2020). Topics included industry take up, human factors, explainabiloity (explainability, justifyability, exploitability) and GI benchmarks. We also contrast various recent online approaches (e.g. SBST 2020) to holding virtual computer science conferences and workshops via the WWW on the Internet without face-2-face interaction. Finally we speculate on how the Coronavirus Covid-19 Pandemic will affect research next year and into the future