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Bark paintings represent a unique artform that originated in Australia and continues to this day. This paper presents a scientific investigation into both the pigments and binders used by Aboriginal artists from across the Northern Territory (NT) and the Kimberley region in Western Australia (WA) and represents the first major study dedicated to identifying these materials in samples taken from paintings. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), Fourier transform infrared (FTIR) and Raman spectroscopy were used to identify the pigments in the four colors commonly associated with works by Aboriginal artists: red, yellow, black, and white. Iron oxides are used for red and yellow. Typically, kaolin is used for white and carbon or natural manganese ores are used for black, although the use of other pigments such as huntite (white) and battery black were seen in paintings from specific locations. Evidence of trade could not be established during this study; however, analysis shows that artists may use different pigments based on location and availability. A combination of FTIR and pyrolysis-gas chromatography-mass spectrometry (pyrolysis-GC-MS) was utilized to investigate the presence of a binder in the paint. Plant-based materials were identified as the binder in the majority of the paintings. The use of orchid juice was common, both as a preparatory layer on the bark substrate and as a paint binder. The presence of synthetic resins was more widespread than anticipated, attributed to both conservation efforts and more modern painting practices. [ABSTRACT FROM AUTHOR]

Social media platforms are increasingly looked at as means to investigate social phenomena like collective events, issues or causes. Digital methods – techniques exclusively focused on online data and shaped by the environment hosting these data – have become part and parcel of these investigations, often approaching platforms as hybrid assemblages of users, infrastructures, and algorithms. In its 'online groundness', this type of digital methods research, however, often tends to skim over the socio-cultural, contextual dimension of both wider social phenomena and social media uses and practices. In this paper, we advance a threefold contribution aimed at both sparking future efforts to address this limitation and aligning digital methods inquiry with contemporary epistemological debates that counter universalistic views of platforms and data. First, we question the degree to which digital methods can inform social investigations of collective events, issues or causes. Second, we advance a digital methods paradigm that addresses platforms as socio-cultural artifacts rather than hybrid assemblages. Finally, by reflecting on how we accessed, handled, and explored 9,000 Instagram visuals and around 400,000 Facebook comments to understand influences on middle class understandings of food consumption in Brazil and South Africa, we illustrate a way to design culturally sensitive digital methods research built on 'quanti-quali' practices. [ABSTRACT FROM AUTHOR]

Examined injury patterns in Little League baseball players over time, using insurance data from 17,221,210 players. Ball-related injuries were the most common. Batters had the greatest number of such injuries. One-quarter of the injuries were considered severe, and 13 players died. Though youth baseball appears to be very safe, there are areas where injury prevention is possible. (SM)

Poly([N.sub.[member of]]-trifiuoroacetyl-L-lysine) was used as a model solute to investigate the potential of nonaqueous capillary electrophoresis (NACE) for the characterization of synthetic organic polymers. The information obtained by NACE was compared to that derived from size exclusion chromatography (SEC) experiments, and the two techniques were found to be complimentary for polymer characterization. On one hand, NACE permitted (i) the separation of oligomers according to their molar mass and (ii) the separation of the polymers according to the nature of the end groups. On the other hand, SEC experiments were used for the characterization of the molar mass distribution for higher molar masses. Due to the tendency of the solutes (polypeptides) to adsorb onto the fused-silica capillary wall, careful attention was paid to the rinsing procedure of the capillary between runs in order to keep the capillary surface clean. For that purpose, the use of electrophoretic desorption under denaturating conditions was very effective. Optimization of the separation was performed by studying (i) the influence of the proportion of methanol in a methanol/acetonitrile mixture and (ii) the influence of acetic acid concentration in the background electrolyte. Highly resolved separation of the oligomers (up to a degree of polymerization n of ~50) was obtained by adding trifluoroacetic acid to the electrolyte. Important information concerning the polymer conformations could be obtained from the mobility data. Two different plots relating the effective mobility data to the degree of polymerization were proposed for monitoring the changes in polymer conformations as a function of the number of monomers.

Reduced-impact baseballs and face guards can lower the risk of injury to children who play baseball, according to researchers who analyzed insurance claims maintained by Little League Baseball Inc. Plastic face guards were as effective as metal face guards. The reduced-impact ball was entirely responsible for the reduction in ball-related injuries.