Development of large-scale quantum computing systems will require radio frequency (RF) and microwave technologies operating reliably at cryogenic temperatures down to tens of milli-Kelvin (mK). The quantum bits in the most promising quantum computing technologies such as the superconducting quantum computing are designed using principles of microwave engineering and operated using microwave signals. The control, readout, and coupling of qubits are implemented using a network of microwave components operating at various temperature stages. To ensure reliable operation of quantum computing systems, it is critical to ensure optimal performance of these microwave components and qubits at their respective operating temperatures, which can be as low as mK temperatures. It is, therefore, critical to understand the microwave characteristics of waveforms, components, circuits, networks, and systems at cryogenic temperatures. The UK’s National Physical Laboratory (NPL) is focussed on developing new microwave measurement capabilities through the UK’s National Quantum Technologies Programme to address various microwave test and measurement challenges in quantum computing. This includes the development of various measurement capabilities to characterize the microwave performance of quantum and microwave devices and substrate materials at cryogenic temperatures. This paper summarizes the roadmap of activities at NPL to address these microwave metrology challenges in quantum computing.

Models of factors controlling late Pleistocene pluvial lake-level fluctuations in the Great Basin are evaluated by dating lake levels in Jakes Valley. “Jakes Lake” rose to a highstand at 13,870 ± 50 14C Yr B.P., receded to a stillstand at 12,440 ± 50 14C yr B.P., and receded steadily to desiccation thereafter. The Jakes Lake highstand is roughly coincident with highstands of lakes Bonneville, Lahontan and Russell. The rise to highstand and recession of Jakes Lake were most likely controlled by a storm track steered by the polar jet stream. The final stillstand of Jakes Lake helps constrain timing of northward retreat of the polar jet stream during the Pleistocene–Holocene transition.

Lacustrine sediments from southeastern Arabia reveal variations in lake level corresponding to changes in the strength and duration of Indian Ocean Monsoon (IOM) summer rainfall and winter cyclonic rainfall. The late glacial/Holocene transition of the region was characterised by the development of mega-linear dunes. These dunes became stabilised and vegetated during the early Holocene and interdunal lakes formed in response to the incursion of the IOM at approximately 8500 cal yr BP with the development of C3 dominated savanna grasslands. The IOM weakened ca. 6000 cal yr BP with the onset of regional aridity, aeolian sedimentation and dune reactivation and accretion. Despite this reduction in precipitation, the lake was maintained by winter dominated rainfall. There was a shift to drier adapted C4 grasslands across the dune field. Lake sediment geochemical analyses record precipitation minima at 8200, 5000 and 4200 cal yr BP that coincide with Bond events in the North Atlantic. A number of these events correspond with changes in cultural periods, suggesting that climate was a key mechanism affecting human occupation and exploitation of this region.

Rapidly-flowing ice streams are an important mechanism through which ice sheets lose mass, and much work has been focussed on elucidating the processes that increase or decrease their velocity. Recent work using standard inverse methods has inferred previously-unrecognised regular patterns of high basal shear stress (‘sticky spots’ >200 kPa) beneath a number of ice streams in Antarctica and Greenland, termed ‘traction ribs’. They appear at a scale intermediate between smaller ribbed moraines and much larger mega-ribs observed on palaeo-ice sheet beds, but it is unclear whether they have a topographic expression at the bed. Here, we report observations of rib-like bedforms from DEMs along palaeo-ice stream beds in western Canada that resemble both the pattern and dimensions of traction ribs. Their identification suggests that traction ribs may have a topographic expression that lies between, and partly overlaps with, ribbed moraines and much larger mega-ribs. These intermediate-sized bedforms support the notion of a ribbed bedform continuum. Their formation remains conjectural, but our observations from palaeo-ice streams, coupled with those from modern ice masses, suggest they are related to wave-like instabilities occurring in the coupled flow of ice and till and modulated by subglacial meltwater drainage. Their form and pattern may also involve glaciotectonism of subglacial sediments.

In this paper, we investigate the effect of neighbourhood density (ND) on vocabulary size in a computational model of vocabulary development. A word has a high ND if there are many words phonologically similar to it. High ND words are more easily learned by infants of all abilities (e.g. Storkel, 2009; Stokes, 2014). We present a neural network model that learns general phonotactic patterns in the exposure language, as well as specific word forms and, crucially, mappings between word meanings and word forms. The network is faster at learning frequent words, and words containing high-probability phoneme sequences, as human word learners are, but, independently of this, the network is also faster at learning words with high ND, and, when its capacity is reduced, it learns high ND words in preference to other words, similarly to late talkers. We analyze the model and propose a novel explanation of the ND effect, in which word meanings play an important role in generating word-specific biases on general phonological trajectories. This explanation leads to a new prediction about the origin of the ND effect in infants.

In 1976, David Sugden and Brian John developed a classification for Antarctic landscapes of glacial erosion based upon exposed and eroded coastal topography, providing insight into the past glacial dynamics of the Antarctic ice sheets. We extend this classification to cover the continental interior of Antarctica by analysing the hypsometry of the subglacial landscape using a recently released dataset of bed topography (BEDMAP2). We used the existing classification as a basis for first developing a low-resolution description of landscape evolution under the ice sheet before building a more detailed classification of patterns of glacial erosion. Our key finding is that a more widespread distribution of ancient, preserved alpine landscapes may survive beneath the Antarctic ice sheets than has been previously recognized. Furthermore, the findings suggest that landscapes of selective erosion exist further inland than might be expected, and may reflect the presence of thinner, less extensive ice in the past. Much of the selective nature of erosion may be controlled by pre-glacial topography, and especially by the large-scale tectonic structure and fluvial valley network. The hypotheses of landscape evolution presented here can be tested by future surveys of the Antarctic ice sheet bed.

There are many reports which suggest that patients with affective illness (mania and/or depression) have abnormalities in the functioning of one or more neurobiological systems. At a conference convened by the Clinical Research Branch, Division of Extramural Research Programs, National Institute of Mental Health, these findings were reviewed and some of the factors impeding movement towards a more complete and integrated view of the functioning of neurobiological systems in patients with mania or depression were identified. As a result, a multi-research centre, collaborative approach to the study of the psychobiology of affective disorders was developed. In this collaborative programme, which has now been underway for several years, the focus has been upon: (a) the assessment of the functioning of several different types of biological systems in the same patient, both before and during treatment; (b) obtaining a reasonably large number of patients and comparison subjects; and (c) the use within and across centres of standardized diagnostic categories and behavioural rating methodologies. In this paper the history, background, and rationale for this collaborative effort are reviewed. Those biological systems chosen for study are noted, and issues such as reliability and validity of diagnoses, measurement of state variables, assessment of change with treatment, and logistical and coordinating problems are discussed.

This paper considers methods to measure output and productivity in the delivery of health services, with an application to NHS hospital sector. It first develops a theoretical framework for measuring quality adjusted outputs and then considers how this might be implemented given available data. Measures of input use are discussed and productivity growth estimates are presented for the period 1998/9-2003/4. The paper concludes that available data are unlikely fully to capture quality improvements.

This article reconsiders sentimentalism in the light of the writings of Adam Smith and the career of Abd al-Halim Hafiz, Egypt’s ‘Dark Nightingale’ and film-star crooner of the 1950s and 60s. It explores competing representations of emotionality, the limits of enchantment, and the contemporary politics of nostalgia and melodrama in Egyptian public culture. Eighteenth-century sentimental theory provides a critical and productive angle on twentieth-century popular musical culture, angles that this paper explores by imagining Adam Smith watching Abd al-Halim Hafiz’s first film, Lahn al-Wafā‘ (1955).

Three sightings of Mesoplodon beaked whales are reported from the Bay of Biscay, north-east Atlantic. All sightings comprised one or two animals, breaching repeatedly in proximity to the survey vessel, and occurred at between 2200 and 4100 m water depth. Descriptive and photographic data are compared with published accounts of Mesoplodon species in the north-east Atlantic, and the identification of the animals as True's beaked whale (Mesoplodon mirus) concurs with all observed features. Within the north-east Atlantic, True's beaked whale is the only Mesoplodon species that could produce the single, closely-spaced parallel-paired scar observed on one animal. Our observations are consistent with the first live sightings of True's beaked whale in the Bay of Biscay, and only the second documented record worldwide.