Professional religious specialists centralised religious authority in early human societies and represented some of the earliest instances of formalised social leadership. These individuals played a central role in the emergence of organised religion and transitions to more stratified human societies. Evolutionary theories highlight a range of environmental, economic and social factors that are potentially causally related to the emergence of professional religious specialists in human history. There remains little consensus over the relative importance of these factors and whether professional religious specialists were the outcome or driver of increased socio-cultural complexity. We built a global dataset of hunter–gatherer societies and developed a novel method of exploratory phylogenetic path analysis. This enabled us to systematically identify the factors associated with the emergence of professional religious specialists and infer the directionality of causal dependencies. We find that environmental predictability, environmental richness, pathogen load, social leadership and food storage systems are all correlated with professional religious specialists. However, only food storage is directly related to the emergence of professional religious specialists. Our findings are most consistent with the claim that the early stages of organised religion were the outcome rather than driver of increased socio-economic complexity.

Physical evidence of weapon trauma in medieval burials is unusual, and evidence for trauma caused by arrowheads is exceptionally rare. Where high frequencies of traumatic injuries have been identified, this is mainly in contexts related to battles; it is much less common in normative burials. Osteological analysis of one context from an assemblage of disarticulated and commingled human bones recovered from a cemetery associated with the thirteenth-century Dominican friary in Exeter, Devon, shows several instances of weapon trauma, including multiple injuries caused by projectile points. Arrow trauma is notoriously difficult to identify, but this assemblage shows that arrows fired from longbows could result in entry and exit wounds in the skull not incomparable to modern gunshot wounds. Microscopic examination of the fracture patterns and spalling associated with these puncture wounds provides tentative evidence that medieval arrows were fletched to spin clockwise. These results have profound implications for our understanding of the power of the medieval longbow, for how we recognise arrow trauma in the archaeological record and for our knowledge of how common violent death and injury were in the medieval past, and how and where casualties were buried.

We consider the numerical solution of competitive exothermic and endothermic reactions in the presence of a chaotic advection flow. The resulting behaviour is characterized by a strong dependence on the competitive reaction history. The burnt temperature is not immediately connected to simple enthalpy calculations, so there is a subtlety in the interplay between the major parameters, notably the Damköhler number, the ratio of the heats of exothermic and endothermic reactions, as well as the ratio of their respective activation energies. This paper seeks to explore the way these parameters affect the steady states of these reaction fronts and their stability.

Sedimentary basins developed along the European margin during the earliest, Permian, stage of proto-Atlantic rifting, during a phase of high heat flow. The proximity of some basins to Caledonian thrusts has implied that rifts locally utilized the basement fabric. New mineralogical and palaeomagnetic data show that thrust planes in the Moine Thrust Zone channelled a pulse of hot fluid in Permian time. The fluids precipitated kaolin in fractures in the thrust zone, and with decreasing intensity away from the zone. The high-temperature polytype dickite is largely confined to major thrust planes. Stable H and O isotope analyses indicate that the parent fluid included meteoric water involved in a hydrothermal system. Coeval hydrothermal hematite has a chemical remanence that dates the fluid pulse as Permian. This is direct evidence for post-orogenic activity in the thrust zone, in which the thrusts vented excess heat during regional crustal extension. The example from the European margin exemplifies the importance of deep-seated structures in the release of heat, and the value of kaolinite polytype mapping as a tool to record anomalous palaeo-heat flow.

Computer-controlled scanning electron microscopy (CCSEM) has been assessed for the determination of form and size distribution of heavy metals in urban contaminated soils. Metal distributions within individual particles were determined using X-ray element mapping. The sites selected for study were (1) around a landfill site, previously a colliery in Wolverhampton, UK and (2) a private garden adjacent to a railway in Nottingham, UK. Backscattered thresholding techniques were used to isolate the Pb-containing categories. The classification results for both Wolverhampton and Nottingham soils were generally similar but more Pb-containing classes were observed for the Nottingham samples when a comparison was made between results of the same size fractions. However, difficulties with the technique arose when particles showing chemically similar weathering crusts were assigned to the same class, despite having different internal compositions. The CCSEM data therefore need to be interpreted with caution and their application limited to situations in which particle internal complexity is not an issue.

Airscrew development has proceeded along four main lines :–

1. (1) Aerodynamic design.

2. (2) Materials.

3. (3) Adaptation to engine and aircraft.

4. (4) Fans for cooling and ventilating purposes.

Section (4) I have omitted. It may form the subject of a paper elsewhere. Section (1) I have barely outlined. It is of great interest, but I have concentrated on Sections (2) and (3) as being of immediate practical concern.

It was with some trepidation that I accepted the Society's invitation to contribute a Chapter to this Centenary issue. As the Lord Chancellor in Iolanthe has it,

“But though the compliment implied
Inflates me with legitimate pride,
It nevertheless can't be denied
That it has its inconvenient side.“

Nearly all those mentioned in the following chronicle of British achievements have known me personally; many have been my colleagues. It would be unfortunate if what I have said, or have failed to say, about their work were to disturb hitherto harmonious relations.

We assessed evidence of exposure to viruses and bacteria in an unmanaged and long-isolated population of Soay sheep (Ovis aries) inhabiting Hirta, in the St Kilda archipelago, 65 km west of Benbecula in the Outer Hebrides of Scotland. The sheep harbour many metazoan and protozoan parasites but their exposure to viral and bacterial pathogens is unknown. We tested for herpes viral DNA in leucocytes and found that 21 of 42 tested sheep were infected with ovine herpesvirus 2 (OHV-2). We also tested 750 plasma samples collected between 1997 and 2010 for evidence of exposure to seven other viral and bacterial agents common in domestic Scottish sheep. We found evidence of exposure to Leptospira spp., with overall seroprevalence of 6·5%. However, serological evidence indicated that the population had not been exposed to border disease, parainfluenza, maedi-visna, or orf viruses, nor to Chlamydia abortus. Some sheep tested positive for antibodies against Mycobacterium avium subsp. paratuberculosis (MAP) but, in the absence of retrospective faecal samples, the presence of this infection could not be confirmed. The roles of importation, the pathogen–host interaction, nematode co-infection and local transmission warrant future investigation, to elucidate the transmission ecology and fitness effects of the few viral and bacterial pathogens on Hirta.

People living with HIV (PLWH) experience greater psychological distress than the general population. Evidence from high-incomes countries suggests that psychological interventions for PLWH can improve mental health symptoms, quality of life, and HIV care engagement. However, little is known about the effectiveness of mental health interventions for PLWH in low- and middle-income countries (LMICs), where the large majority of PLWH reside. This systematized review aims to synthesize findings from mental health intervention trials with PLWH in LMICs to inform the delivery of mental health services in these settings. A systematic search strategy was undertaken to identify peer-reviewed published papers of intervention trials addressing negative psychological states or disorders (e.g. depression, anxiety) among PLWH in LMIC settings. Search results were assessed against pre-established inclusion and exclusion criteria. Data from papers meeting criteria were extracted for synthesis. Twenty-six papers, published between 2000 and 2014, describing 22 unique interventions were identified. Trials were implemented in sub-Saharan Africa (n = 13), Asia (n = 7), and the Middle East (n = 2), and addressed mental health using a variety of approaches, including cognitive-behavioral (n = 18), family-level (n = 2), and pharmacological (n = 2) treatments. Four randomized controlled trials reported significant intervention effects in mental health outcomes, and 11 preliminary studies demonstrated promising findings. Among the limited mental health intervention trials with PLWH in LMICs, few demonstrated efficacy. Mental health interventions for PLWH in LMICs must be further developed and adapted for resource-limited settings to improve effectiveness.