Ideology can be understood as a type of cultural system, a set of interrelated meanings that are symbolically mediated through semiotic devices such as metaphors. Ideologies underlie social orders as well as help people make sense of their environment and decide on courses of action. While much has been said about ideology, little has been written on the sources of ideological change beyond pointing to ideological entrepreneurship. Even less has been written on the relationship between violent and disruptive social movements and ideology beyond pointing to the ideological motivations for the movements. We contend that extreme protests are often triggered by an ideological crisis, that is, an intolerable disconnection between the ideology adopted by some group and the current circumstances or, alternatively, an inability of their ideology to make sense of their current situation. Moreover, extreme protests are a form of ideological work, as they are often sources of ideological inspiration, development, and change.

Recent research has shown the potential of speleothem δ13C to record a range of environmental processes. Here, we report on 230Th-dated stalagmite δ13C records for southwest Sulawesi, Indonesia, over the last 40,000 yr to investigate the relationship between tropical vegetation productivity and atmospheric methane concentrations. We demonstrate that the Sulawesi stalagmite δ13C record is driven by changes in vegetation productivity and soil respiration and explore the link between soil respiration and tropical methane emissions using HadCM3 and the Sheffield Dynamic Global Vegetation Model. The model indicates that changes in soil respiration are primarily driven by changes in temperature and CO2, in line with our interpretation of stalagmite δ13C. In turn, modelled methane emissions are driven by soil respiration, providing a mechanism that links methane to stalagmite δ13C. This relationship is particularly strong during the last glaciation, indicating a key role for the tropics in controlling atmospheric methane when emissions from high-latitude boreal wetlands were suppressed. With further investigation, the link between δ13C in stalagmites and tropical methane could provide a low-latitude proxy complementary to polar ice core records to improve our understanding of the glacial–interglacial methane budget.

Parochialism, by which we mean in-group preferences and out-group prejudice, has the potential to influence public policy. In-group preferences and out-group prejudice can lead individuals to evaluate a policy based on how that policy affects the groups they belong to rather than on the basis of their ideological priors or the impact of that policy on society at large. Unchecked, parochialism likely leads to problematic policies and perverse social outcomes. While the evidence suggests that this bias can be mitigated if issues are framed in ways that encourage reflection as opposed to unreflective immediate responses, policy makers face incentives to leverage parochialism rather than combat it. The solution may instead require limiting policy makers and our ability to make decisions for others and promoting an institutional environment that encourages our interacting with diverse others rather than insularity. Stated another way, limited government and open society may be the path beyond our parochialism.

Archaeological studies of Early Islamic communities in Central Asia have focused on lowland urban communities. Here, the authors report on recent geophysical survey and excavation of an Early Islamic cemetery at Tashbulak in south-eastern Uzbekistan. AMS dating places the establishment of the cemetery in the mid-eighth century AD, making it one of the earliest Islamic burial grounds documented in Central Asia. Burials at Tashbulak conform to Islamic prescriptions for grave form and body deposition. The consistency in ritual suggests the existence of a funerary community of practice, challenging narratives of Islamic conversion in peripheral areas as a process of slow diffusion and emphasising the importance of archaeological approaches for documenting the diversity of Early Islamic communities.

Cu-doping and crystallographic site occupations within the half-Heusler (HH) TiNiSn, a promising thermoelectric material, have been examined by atom probe tomography. In particular, this investigation aims to better understand the influence of atom probe analysis conditions on the measured chemical composition. Under a voltage-pulsing mode, atomic planes are clearly resolved and suggest an arrangement of elements in-line with the expected HH (F-43m space group) crystal structure. The Cu dopant is also distributed uniformly throughout the bulk material. For operation under laser-pulsed modes, the returned composition is highly dependent on the selected laser energy, with high energies resulting in the measurement of excessively high absolute Ti counts at the expense of Sn and in particular Ni. High laser energies also appear to be correlated with the detection of a high fraction of partial hits, indicating nonideal evaporation behavior. The possible mechanisms for these trends are discussed, along with suggestions for optimal analysis conditions for these and similar thermoelectric materials.

We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band ( ${\sim}60\%$ ), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific and technical aspects of the new receiver, including its astronomical objectives, as well as the feed, receiver, digitiser, and signal processor design. We describe the pipeline routines that form the archive-ready data products and how those data files can be accessed from the archives. The system performance is quantified, including the system noise and linearity, beam shape, antenna efficiency, polarisation calibration, and timing stability.

Although the Cascajal Block (CB), an incised greenstone slab from southeastern Veracruz, Mexico, arguably contains the earliest written text in the New World, debate remains regarding the object's authenticity, dating, and cultural affiliation. To address these issues, this article details recent analyses of the CB via polynomial texture mapping (PTM), X-ray fluorescence (XRF), and scanning electron microscopy (SEM). PTM revealed new details that have resulted in a new epigraphic drawing of the block's incised text and allowed for improved identification of several constituent signs. Spectrometric analysis confirmed that the chemical composition of the CB matrix is consistent with serpentine and identified a uniform patina on its surface, which provided additional contextual data. SEM micrographs of polymer replica molds taken from the incised text evidence manufacturing traces that correspond to lapidary techniques observed on other Formative-period Olmec objects of secure provenience. Results assist in clarifying the archaeological contexts of the object and confirm that in terms of symbols, material, and manufacture the CB conforms to other Formative-period Olmec objects, supporting the object's authenticity, dating, and cultural affiliation.

We report on the Bulge Asymmetries and Dynamic Evolution (BAaDE) survey which has observed 19 000 MSX color selected red giant stars for SiO maser emission at 43 GHz with the VLA and is in the process of observing 9 000 of these stars with ALMA at 86 GHz in the Southern sky. Our setup covers the main maser transitions, as well as those of isotopologues and selected lines of carbon-bearing species. Observations of this set of lines allow a far-reaching catalog of line-of-sight velocities in the dust-obscured regions where optical surveys cannot reach. Our preliminary detection rate is close to 70%, predicting a wealth of new information on the distribution of metal rich stars, their kinematics as function of location in the Galaxy, as well as the occurrence of lines and line ratios between the different transitions in combination with the spectral energy distribution from about 1 to 100 μm. Similar to the OH/IR stars, a clear kinematic signature between disk and bulge stars can be seen. Furthermore, the SiO J = →10 (v=3) line plays a prominent role in the derived maser properties.