In this article, we argue that landesque capital was integral to the development of complexity in the Maya Lowlands. Such features involved permanent investments in the landscape that supported material and ideological practices, resulting in increased sustainability and well-being. We contend that these developments stemmed from accretional modifications to soils in the Preceramic/Early Preclassic, as well as intentional investments of labor in agricultural features, large public works, and select civic complexes during the Middle Preclassic. Capital improvements were particularly important during the Middle Preclassic, when sedentary occupations and civic life were established. The timing and location of the investments strongly correlate with other aspects of Middle Preclassic lifeways, such as the transition to sedentism, acquisition and control of resources, changes in lithic production, and the emergence of an elite class. We note that some of the largest investments in landscape management during the Middle Preclassic occurred in the Central Karstic Uplands, where substantial cities rose in the Late Preclassic. We conclude that during the Middle Preclassic an ontology of landesque capital developed, based on the synergistic fusing of daily and ritual practices with physical features, which provided a foundation for resilience, sustainability, and well-being in subsequent generations.

The mechanics underlying ice–skate friction remain uncertain despite over a century of study. In the 1930s, the theory of self-lubrication from frictional heat supplanted an earlier hypothesis that pressure melting governed skate friction. More recently, researchers have suggested that a layer of abraded wear particles or the presence of quasi-liquid molecular layers on the surface of ice could account for its slipperiness. Here, we assess the dominant hypotheses proposed to govern ice–skate friction and describe experiments conducted in an indoor skating rink aimed to provide observations to test these hypotheses. Our results indicate that the brittle failure of ice under rapid compression plays a strong role. Our observations did not confirm the presence of full-contact water films and are more consistent with the presence of lubricating ice-rich slurries at discontinuous high-pressure zones (HPZs). The presence of ice-rich slurries supporting skates through HPZs merges pressure-melting, abrasion and lubricating films as a unified hypothesis for why skates are so slippery across broad ranges of speeds, temperatures and normal loads. We suggest tribometer experiments to overcome the difficulties of investigating these processes during actual skating trials.

We present an overview of the Middle Ages Galaxy Properties with Integral Field Spectroscopy (MAGPI) survey, a Large Program on the European Southern Observatory Very Large Telescope. MAGPI is designed to study the physical drivers of galaxy transformation at a lookback time of 3–4 Gyr, during which the dynamical, morphological, and chemical properties of galaxies are predicted to evolve significantly. The survey uses new medium-deep adaptive optics aided Multi-Unit Spectroscopic Explorer (MUSE) observations of fields selected from the Galaxy and Mass Assembly (GAMA) survey, providing a wealth of publicly available ancillary multi-wavelength data. With these data, MAGPI will map the kinematic and chemical properties of stars and ionised gas for a sample of 60 massive ( ${>}7 \times 10^{10} {\mathrm{M}}_\odot$ ) central galaxies at $0.25 < z <0.35$ in a representative range of environments (isolated, groups and clusters). The spatial resolution delivered by MUSE with Ground Layer Adaptive Optics ( $0.6-0.8$ arcsec FWHM) will facilitate a direct comparison with Integral Field Spectroscopy surveys of the nearby Universe, such as SAMI and MaNGA, and at higher redshifts using adaptive optics, for example, SINS. In addition to the primary (central) galaxy sample, MAGPI will deliver resolved and unresolved spectra for as many as 150 satellite galaxies at $0.25 < z <0.35$ , as well as hundreds of emission-line sources at $z < 6$ . This paper outlines the science goals, survey design, and observing strategy of MAGPI. We also present a first look at the MAGPI data, and the theoretical framework to which MAGPI data will be compared using the current generation of cosmological hydrodynamical simulations including EAGLE, Magneticum, HORIZON-AGN, and Illustris-TNG. Our results show that cosmological hydrodynamical simulations make discrepant predictions in the spatially resolved properties of galaxies at $z\approx 0.3$ . MAGPI observations will place new constraints and allow for tangible improvements in galaxy formation theory.

The first demonstration of laser action in ruby was made in 1960 by T. H. Maiman of Hughes Research Laboratories, USA. Many laboratories worldwide began the search for lasers using different materials, operating at different wavelengths. In the UK, academia, industry and the central laboratories took up the challenge from the earliest days to develop these systems for a broad range of applications. This historical review looks at the contribution the UK has made to the advancement of the technology, the development of systems and components and their exploitation over the last 60 years.

We study the evolution of unidirectional water waves from a randomly forced input condition with uncorrelated Fourier components. We examine the kurtosis of the linearised free surface as a convenient proxy for the probability of a rogue wave. We repeat the laboratory experiments of Onorato et al. (Phys. Rev. E, vol. 70, 2004, 067302), both experimentally and numerically, and extend the parameter space in our numerical simulations. We consider numerical simulations based on the modified nonlinear Schrödinger equation and the fully nonlinear water wave equations, which are in good agreement. For low steepness, existing analytical models based on the nonlinear Schrödinger equation (NLS) are found to be accurate. For cases which are steep or have very narrow bandwidths, these analytical models over-predict the rate at which excess kurtosis develops. In these steep cases, the kurtosis in both our experiments and numerical simulations peaks before returning to an equilibrium level. Such transient maxima are not predicted by NLS-based analytical models. Above a certain threshold of steepness, the steady-state value of kurtosis is primarily dependent on the spectral bandwidth. We also examine how the average shape of extreme events is modified by nonlinearity over the evolution distance, showing significant asymmetry during the initial evolution, which is greatly reduced once the spectrum has reached equilibrium. The locations of the maxima in asymmetry coincide approximately with the locations of the maxima in kurtosis.

We have investigated steep three-dimensional surface gravity wave groups formed by dispersive focusing using a fully nonlinear potential flow solver. We find that third-order resonant interactions result in rapid energy transfers to higher wavenumbers and reduced directional spreading during focusing, followed by spectral broadening during defocusing, forming steep wave groups with augmented kinematics and a prolonged lifespan. If the wave group is initially narrow-banded, quasi-degenerate interactions arise, characterised by energy transfers along the resonance angle, ${\pm }35.26^{\circ }$, of the Phillips ‘figure-of-eight’ loop. Spectral broadening due to the quasi-degenerate interactions facilitates non-degenerate interactions, characterised by oblique energy transfers at approximately ${\pm }55^{\circ }$ to the spectral peak. We consider the influence of steepness, finite depth, directional spreading and the high-wavenumber tail on spectral evolution. Steepness is found to augment both the quasi-degenerate and non-degenerate interactions similarly. However, a reduction in depth is found to weaken the quasi-degenerate interactions more severely than the non-degenerate interactions. We observe that increased directional spreading reduces spectral evolution, partially because wave groups with more spreading focus for a shorter duration due to linear dispersion. However, we also find that directional spreading reduces the peak rates of energy transfer. Inclusion of the high-wavenumber tail of the Joint North Sea Wave Project spectrum further reduces rates of energy transfer compared with a Gaussian wavenumber spectrum. Thus, directional spreading and the high-wavenumber tail may be integral to a form of spectral equilibrium that reduces rapid energy transfers during a steep wave event.

We analyzed the δ2H composition of n-alkanes isolated from Laguna Zoncho, a small lake in southern Pacific Costa Rica, to reconstruct paleohydrology. Using a core that spans the past 3600 years, we found evidence of dry periods, most notably during the Terminal Classic Drought (TCD; ~1200 cal yr BP) and the Little Ice Age (~400 cal yr BP). Previous work at Laguna Zoncho, using bulk sedimentary δ13C and geochemical analysis, found that agriculture began to decline during the TCD. Our δ2H records confirm the occurrence of arid conditions coincident with the TCD at Laguna Zoncho and show that, despite receiving more than 3000 mm of precipitation per year, this region is susceptible to multidecadal droughts.

Clinical interviews are typically used in the assessment psychosis and related clinical symptoms. However, these measures are limited by recall bias and averaging, and thus important information is lost. Ambulatory real-time monitoring devices have the advantage of providing detailed and sensitive information about symptoms. This can provide valuable information about change and fluctuations in symptoms across time. Suicide represents a substantial problem in psychiatry, but little is known about the immediate triggers of suicidal ideation. Psychological theory suggests that the instability, in addition to the intensity, of depressed mood may be an important risk factor for the development of suicidal ideation. Mobile phone-based assessments may allow for a more accurate measure of suicidality and mood across time. In this presentation, a new smart phone software application (ClinTouch) for the assessment of psychotic and related symptoms will be described. Research investigating the feasibility, acceptability, and limitations of mobile-phone based assessment will be discussed in relation to people with psychosis. Mobile phone-based research investigating the short-term predictors of thoughts about self-injury will also be considered. The talk will finish with an outline of how mobile-based assessments could be applied in clinical settings.

Following an outbreak of highly pathogenic avian influenza virus (HPAIV) in a poultry house, control measures are put in place to prevent further spread. An essential part of the control measures based on the European Commission Avian Influenza Directive 2005/94/EC is the cleansing and disinfection (C&D) of infected premises. Cleansing and disinfection includes both preliminary and secondary C&D, and the dismantling of complex equipment during secondary C&D is also required, which is costly to the owner and also delays the secondary cleansing process, hence increasing the risk for onward spread. In this study, a quantitative risk assessment is presented to assess the risk of re-infection (recrudescence) occurring in an enriched colony-caged layer poultry house on restocking with chickens after different C&D scenarios. The risk is expressed as the number of restocked poultry houses expected before recrudescence occurs. Three C&D scenarios were considered, namely (i) preliminary C&D alone, (ii) preliminary C&D plus secondary C&D without dismantling and (iii) preliminary C&D plus secondary C&D with dismantling. The source-pathway-receptor framework was used to construct the model, and parameterisation was based on the three C&D scenarios. Two key operational variables in the model are (i) the time between depopulation of infected birds and restocking with new birds (TbDR) and (ii) the proportion of infected material that bypasses C&D, enabling virus to survive the process. Probability distributions were used to describe these two parameters for which there was recognised variability between premises in TbDR or uncertainty due to lack of information in the fraction of bypass. The risk assessment estimates that the median (95% credible intervals) number of repopulated poultry houses before recrudescence are 1.2 × 104 (50 to 2.8 × 106), 1.9 × 105 (780 to 5.7 × 107) and 1.1 × 106 (4.2 × 103 to 2.9 × 108) under C&D scenarios (i), (ii) and (iii), respectively. Thus for HPAIV in caged layers, undertaking secondary C&D without dismantling reduces the risk by 16-fold compared to preliminary C&D alone. Dismantling has an additional, although smaller, impact, reducing the risk by a further 6-fold and thus around 90-fold compared to preliminary C&D alone. On the basis of the 95% credible intervals, the model demonstrates the importance of secondary C&D (with or without dismantling) over preliminary C&D alone. However, the extra protection afforded by dismantling may not be cost beneficial in the context of reduced risk of onward spread.

The dysfunctional cognitive and reasoning biases which underpin psychotic symptoms are likely to present prior to the onset of a diagnosable disorder and should therefore be detectable along the psychosis continuum in individuals with schizotypal traits. Two reasoning biases, Bias Against Disconfirmatory Evidence (BADE) and Jumping to Conclusions (JTC), describe how information is selected and weighed under conditions of uncertainty during decision making. It is likely that states such as elevated stress exacerbates JTC and BADE in individuals with high schizotypal traits vulnerable to displaying these information gathering styles. Therefore, we evaluated whether stress and schizotypy interacted to predict these reasoning biases using separate samples from the US (JTC) and England (BADE). Generally speaking, schizotypal traits and stress were not independently associated with dysfunctional reasoning biases. However, across both studies, the interaction between schizotypy traits and stress significantly predicted reasoning biases such that increased stress was associated with increased reasoning biases, but only for individuals low in schizotypal traits. These patterns were observed for positive schizotypal traits (in both samples), for negative traits (in the England sample only), but not for disorganization traits. For both samples, our findings suggest that the presence of states such as stress is associated with, though not necessarily dysfunctional, reasoning biases in individuals with low schizotypy. These reasoning biases seemed, in some ways, relatively immutable to stress in individuals endorsing high levels of positive schizotypal traits.

Owing to the interplay between the forward Stokes drift and the backward wave-induced Eulerian return flow, Lagrangian particles underneath surface gravity wave groups can follow different trajectories depending on their initial depth below the surface. The motion of particles near the free surface is dominated by the waves and their Stokes drift, whereas particles at large depths follow horseshoe-shaped trajectories dominated by the Eulerian return flow. For unidirectional wave groups, a small net displacement in the direction of travel of the group results near the surface, and is accompanied by a net particle displacement in the opposite direction at depth. For deep-water waves, we study these trajectories experimentally by means of particle tracking velocimetry in a two-dimensional flume. In doing so, we provide visual illustration of Lagrangian trajectories under groups, including the contributions of both the Stokes drift and the Eulerian return flow to both the horizontal and the vertical Lagrangian displacements. We compare our experimental results to leading-order solutions of the irrotational water wave equations, finding good agreement.