How genealogies are affected by the speed of evolution

In a series of recent works it has been shown that a class of simple models of evolving populations under selection leads to genealogical trees whose statistics are given by the Bolthausen-Sznitman coalescent rather than by the well known Kingman coalescent in the case of neutral evolution. Here we show that when conditioning the genealogies on the speed of evolution, one finds a one parameter family of tree statistics which interpolates between the Bolthausen-Sznitman and Kingman's coalescents. This interpolation can be calculated explicitly for one specific version of the model, the exponential model. Numerical simulations of another version of the model and a phenomenological theory indicate that this one-parameter family of tree statistics could be universal. We compare this tree structure with those appearing in other contexts, in particular in the mean field theory of spin glasses

A Recirculating Eddy Promotes Subsurface Particle Retention in an Antarctic Biological Hotspot

Palmer Deep Canyon is one of the biological hotspots associated with deep bathymetric features along the Western Antarctic Peninsula. The upwelling of nutrient-rich Upper Circumpolar Deep Water to the surface mixed layer in the submarine canyon has been hypothesized to drive increased phytoplankton biomass productivity, attracting krill, penguins and other top predators to the region. However, observations in Palmer Deep Canyon lack a clear in-situ upwelling signal, lack a physiological response by phytoplankton to Upper Circumpolar Deep Water in laboratory experiments, and surface residence times that are too short for phytoplankton populations to reasonably respond to any locally upwelled nutrients. This suggests that enhanced local upwelling may not be the mechanism that links canyons to increased biological activity. Previous observations of isopycnal doming within the canyon suggested that a subsurface recirculating feature may be present. Here, using in-situ measurements and a circulation model, we demonstrate that the presence of a recirculating eddy may contribute to maintaining the biological hotspot by increasing the residence time at depth and retaining a distinct layer of biological particles. Neutrally buoyant particle simulations showed that residence times increase to upwards of 175 days with depth within the canyon during the austral summer. In-situ particle scattering, flow cytometry, and water samples from within the subsurface eddy suggest that retained particles are detrital in nature. Our results suggest that these seasonal, retentive features of Palmer Deep Canyon are important to the establishment of the biological hotspot

A Subsurface Eddy Associated With a Submarine Canyon Increases Availability and Delivery of Simulated Antarctic Krill to Penguin Foraging Regions

The distribution of marine zooplankton depends on both ocean currents and swimming behavior. Many zooplankton perform diel vertical migration (DVM) between the surface and subsurface, which can have different current regimes. If concentration mechanisms, such as fronts or eddies, are present in the subsurface, they may impact zooplankton near-surface distributions when they migrate to near-surface waters. A subsurface, retentive eddy within Palmer Deep Canyon (PDC), a submarine canyon along the West Antarctic Peninsula (WAP), retains diurnal vertically migrating zooplankton in previous model simulations. Here, we tested the hypothesis that the presence of the PDC and its associated subsurface eddy increases the availability and delivery of simulated Antarctic krill to nearby penguin foraging regions with model simulations over a single austral summer. We found that the availability and delivery rates of simulated krill to penguin foraging areas adjacent to PDC were greater when the PDC was present compared to when PDC was absent, and when DVM was deepest. These results suggest that the eddy has potential to enhance krill availability to upper trophic level predators and suggests that retention may play a significant role in resource availability for predators in other similar systems along the WAP and in other systems with sustained subsurface eddies

Subsurface Eddy Facilitates Retention of Simulated Diel Vertical Migrators In a Biological Hotspot

Diel vertical migration (DVM) is common in zooplankton populations worldwide. Every day, zooplankton leave the productive surface ocean and migrate to deepwater to avoid visual predators and return to the surface at night to feed. This behavior may also help retain migrating zooplankton in biological hotspots. Compared to fast and variable surface currents, deep ocean currents are sluggish, and can be more consistent. The time spent in the subsurface layer is driven by day length and the depth of the surface mixed layer. A subsurface, recirculating eddy has recently been described in Palmer Deep Canyon (PDC), a submarine canyon in a biological hotspot located adjacent to the West Antarctic Peninsula. Circulation model simulations have shown that residence times of neutrally buoyant particles increase with depth within this feature. We hypothesize that DVM into the subsurface eddy increases local retention of migrating zooplankton in this feature and that shallow mixed layers and longer days increase residence times. We demonstrate that simulated vertically migrating zooplankton can have residence times on the order of 30 days over the canyon, which is five times greater than residence times of near-surface, nonmigrating zooplankton within PDC and other adjacent coastal regions. The potential interaction of zooplankton with this subsurface feature may be important to the establishment of the biological hotspot around PDC by retaining food resources in the region. Acoustic field observations confirm the presence of vertical migrators in this region, suggesting that zooplankton retention due to the subsurface eddy is feasible

Protocol for a randomised controlled trial comparing laparoscopic cholecystectomy with observation/conservative management for preventing recurrent symptoms and complications in adults with uncomplicated symptomatic gallstones (C-Gall trial)

Acknowledgments Previous CHaRT director John Norrie for his work with the concept of this study. Funding The trial is funded by the NIHR Health Technology Assessment (HTA) Programme (funder number: 14/192/71).Peer reviewedPublisher PD

Plasmodium knowlesi in Human, Indonesian Borneo

Plasmodium knowlesi is now established as the fifth Plasmodium species to cause malaria in humans. We describe a case of P. knowlesi infection acquired in Indonesian Borneo that was imported into Australia. Clinicians need to consider this diagnosis in a patient who has acquired malaria in forest areas of Southeast Asia

Outcomes assessment for people with long-term neurological conditions : a qualitative approach to developing and testing a checklist in integrated care

Background: Failure to demonstrate the effect of integration on service users using conventional outcome measures suggests that research to date has failed to measure the outcomes that actually matter to people with complex long-term conditions and that might result from integrated health and social care. Developing outcome measures that capture the important issues for service users may also help to better reflect the particular ways integrated teams work and what such teams strive to achieve in addressing service user outcomes. Objectives: The objectives of this research were to (1) identify factors that affect integration between health and social care, (2) identify outcomes important to people with long-term neurological conditions (LTNCs) who are clients of an 'integrated' service, (3) develop these outcomes into a checklist and explore whether or not these outcomes can be assessed in practice, and (4) understand how different models of integration affect outcomes. Design, methods and participants: A case study approach, using in-depth, semistructured interviews, was adopted. The cases were four English primary care trusts (PCTs) and their associated local authorities. Case sites had a neurological-rehabilitation team (NRT), each with a different approach to health and social care integration. The research took place in three stages. In stage 1, interviews with 43 commissioners, managers, NRT staff and social care practitioners, and documentary analysis, helped to understand service contexts and approaches to assessment. Interviews, guided by earlier outcomes work, were held with 35 people with LTNCs to identify important outcomes. Interviews with 13 carers illustrated relationships between NRTs and carers. In stage 2, these outcomes were developed into a checklist in partnership with NRTs. NRTs used the outcomes checklist (OC) as part of their routine assessment, and we monitored its use. In stage 3, we conducted interviews and focus groups with 21 NRT staff and 12 clients to evaluate the use of the OC in practice. Analysis: Qualitative data were managed and analysed thematically using the framework approach. Results: Person, service and structural-level factors influenced integration between health and social care. Relationships between practitioners and services often drove integration in practice. However, wider structural arrangements were important and could facilitate these relationships. We identified 20 outcomes important to people with LTNCs. These were grouped into three outcome domains: personal comfort, economic and social participation, and autonomy. Use of the OC in practice was viewed differently by the NRTs. One NRT felt that it duplicated existing assessments, one felt that it covered issues outside their remit and two felt that the OC worked for them. Some of the outcomes could be difficult for staff and clients to raise but clients felt that they should all be included in assessments. Use of the OC was sometimes challenging due to staffing and caseload pressures, changes to service structures and remit, and competing demands of other compulsory paperwork. All NRTs thought that the OC had potential value as a benchmarking or training tool. Larger, more interdisciplinary models of integrated NRTs appeared to give more scope for interpreting, assessing and potentially achieving outcomes. Conclusions: Many of the outcomes that are important to service users with LTNCs are not addressed in validated 'outcome measures'. This has implications for commissioners and practitioners to ensure that service users' needs are met in practice. Turning the OC into a measurement tool could go some way to addressing this. Many of the outcomes are interdependent, an impact on one particular outcome will have a 'knock-on' effect on other outcomes. These inter-relationships demonstrate the complexity of what is important in the lives of people with LTNCs. Service changes can affect integrated arrangements negatively. More research is needed to explore the longer-term effects of organisational change on integrated service provision

Effectiveness of conservative management versus laparoscopic cholecystectomy in the prevention of recurrent symptoms and complications in adults with uncomplicated symptomatic gallstone disease (C-GALL trial) : pragmatic, multicentre randomised controlled trial

Acknowledgments This project will be published in full in the National Institute for Health and Care Research (NIHR) Health Technology Assessment (HTA) programme series. Data monitoring committee: Catherine Hewitt (University of York), Jonathan Lund (University of Nottingham), Tim McAdam (Belfast Health and Social Care Trust), and Amir Nisar (Maidstone and Tunbridge Wells NHS Trust). Trial steering group: David Beard (University of Oxford), Ian Beckingham (Nottingham University Hospitals NHS Trust), John Leeds (Newcastle Hospitals NHS Foundation Trust), and Dee McDonald (patient representative). Funding: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment (HTA) programme (project No 14/192/71). The Health Services Research Unit of the University of Aberdeen is funded in part by the chief scientist’s office of the Scottish government’s health and social care directorates. The views and opinions expressed therein are those of the authors and do not necessarily reflect those of the chief scientist’s office, HTA programme, NIHR, NHS, or Department of Health. The funder had no role in the study design, data collection, data analysis, data interpretation, or writing of the report.Peer reviewedPublisher PD

Household networks and emergent territory: a GIS study of Chumash households, villages and rock-art in South-Central California

Elite households of the Californian Chumash have been studied in order to understand the development of Late Holocene hunter-gatherer alliance networks. Equally, models of what has been termed ‘tribelet territories’ have been used to describe land ownership within larger Californian concepts. Surprisingly little research has explicitly addressed issues of how such territories may have developed. In this article, we turn to DeLanda’s philosophy of social complexity to consider how Chumash households may have underpinned the development of tribelet territories and the political implications for their articulation with wider alliances. Importantly, utilizing Geographic Information Systems (GIS), we analyse potential mobility patterns in relation to households, villages and rock-art locales in a case from the Emigdiano Chumash. The results suggest that the painting of rock art was imbricated within processes of territorialization, and that the local placement of art reflects which villages were home to particularly high-status households