Fragments of the earliest land plants

The earliest fossil evidence for land plants comes from microscopic dispersed spores. These microfossils are abundant and widely distributed in sediments, and the earliest generally accepted reports are from rocks of mid-Ordovician age (Llanvirn, 475 million years ago). Although distribution, morphology and ultrastructure of the spores indicate that they are derived from terrestrial plants, possibly early relatives of the bryophytes, this interpretation remains controversial as there is little in the way of direct evidence for the parent plants. An additional complicating factor is that there is a significant hiatus between the appearance of the first dispersed spores and fossils of relatively complete land plants (megafossils): spores predate the earliest megafossils (Late Silurian, 425 million year ago) by some 50 million years. Here we report the description of spore-containing plant fragments from Ordovician rocks of Oman. These fossils provide direct evidence for the nature of the spore-producing plants. They confirm that the earliest spores developed in large numbers within sporangia, providing strong evidence that they are the fossilized remains of bona fide land plants. Furthermore, analysis of spore wall ultrastructure supports liverwort affinities

Selecting children for head CT following head injury

OBJECTIVE: Indicators for head CT scan defined by the 2007 National Institute for Health and Care Excellence (NICE) guidelines were analysed to identify CT uptake, influential variables and yield. DESIGN: Cross-sectional study. SETTING: Hospital inpatient units: England, Wales, Northern Ireland and the Channel Islands. PATIENTS: Children (3 years were much more likely to have CT than those <3 years (OR 2.35 (95% CI 2.08 to 2.65)). CONCLUSION: Compliance with guidelines and diagnostic yield was variable across age groups, the type of hospital and region where children were admitted. With this pattern of clinical practice the risks of both missing intracranial injury and overuse of CT are considerable

Exploring connections among the multiple outputs and outcomes emerging from 25 years of sea turtle conservation in Northern Cyprus

This is the author accepted manuscriptMonitoring and evaluation is an essential stage of conservation implementation, offering a wide variety of benefits including the ability to engage in informed adaptive management. Understanding the relationship among actions, outputs, and outcomes can inform on factors acting to facilitate or hinder conservation success. Assessing these relationships is particularly important for projects with both social and ecological objectives given that they likely operate through a more complex theory of change. Performance measurement studies that assess both ecological and social variables can offer an informative and cost-effective evaluation method for such projects, but simultaneous social-ecological evaluation is rarely implemented. Using the case study of the Marine Turtle Conservation Project in North Cyprus, we aimed to demonstrate how social-ecological performance measure protocols can aid sea turtle conservation efforts in adaptive management through informing on connections among project actions, outputs, and outcomes. Our study employed a mixed-methods performance measurement approach integrating three distinct data sources: 31 project publications, the project’s long-term dataset on sea turtle ecology, and 26 semi-structured interviews with key informants including residents, fishermen, local business owners, and project staff. The results indicated that the project has generated a wide range of social, economic, and ecological outcomes. Two primary connections among social and ecological factors emerged: 1) bridging the research-implementation gap through directing research into policy action and 2) enhanced operational capacity and achievement of ecological outcomes through extensively engaging with the community and generating local economic benefits. Insufficient government enforcement and a lack of widespread behavioural change on turtle nesting beaches were primary barriers. This study highlights the benefits of multi-disciplinary conservation and demonstrates the insight that can be gained from rapid, social-ecological performance measurement approaches. Channelling such information back into conservation through adaptive management can serve to both increase the achievement of ecological goals and improve human wellbeing.Darwin Initiativ

Spearhead Nanometric Field-Effect Transistor Sensors for Single-Cell Analysis.

Nanometric field-effect-transistor (FET) sensors are made on the tip of spear-shaped dual carbon nanoelectrodes derived from carbon deposition inside double-barrel nanopipettes. The easy fabrication route allows deposition of semiconductors or conducting polymers to comprise the transistor channel. A channel from electrodeposited poly pyrrole (PPy) exhibits high sensitivity toward pH changes. This property is exploited by immobilizing hexokinase on PPy nano-FETs to give rise to a selective ATP biosensor. Extracellular pH and ATP gradients are key biochemical constituents in the microenvironment of living cells; we monitor their real-time changes in relation to cancer cells and cardiomyocytes. The highly localized detection is possible because of the high aspect ratio and the spear-like design of the nano-FET probes. The accurately positioned nano-FET sensors can detect concentration gradients in three-dimensional space, identify biochemical properties of a single living cell, and after cell membrane penetration perform intracellular measurements

Mechanical Properties of End-crosslinked Entangled Polymer Networks using Sliplink Brownian Dynamics Simulations

The mechanical properties of a polymeric network containing both crosslinks and sliplinks (entanglements) are studied using a multi-chain Brownian dynamics simulation. We coarse-grain at the level of chain segments connecting consecutive nodes (cross- or sliplinks), with particular attention to the Gaussian statistics of the network. Affine displacement of nodes is not imposed: their displacement as well as sliding of monomers through sliplinks is governed by force balances. The simulation results of stress in uniaxial extension and the full stress tensor in simple shear including the (non-zero) second normal stress difference are presented for monodisperse chains with up to 18 entanglements between two crosslinks. The cases of two different force laws of the subchains (Gaussian chains and chains with finite extensibility) for two different numbers of monomers in a subchain (no = 50 and no = 100) are examined. It is shown that the additivity assumption of slip- and crosslink contribution holds for sufficiently long chains with two or more entanglements, and that it can be used to construct the strain response of a network of infinitely long chains. An important consequence is that the contribution of sliplinks to the small-strain shear modulus is about &#8532; of the contribution of a crosslink

Staphylococcus aureus extracellular adherence protein triggers TNF alpha release, promoting attachment to endothelial cells via protein A

Staphylococcus aureus is a leading cause of bacteraemia, which frequently results in complications such as infective endocarditis, osteomyelitis and exit from the bloodstream to cause metastatic abscesses. Interaction with endothelial cells is critical to these complications and several bacterial proteins have been shown to be involved. The S. aureus extracellular adhesion protein (Eap) has many functions, it binds several host glyco-proteins and has both pro- and anti-inflammatory activity. Unfortunately its role in vivo has not been robustly tested to date, due to difficulties in complementing its activity in mutant strains. We previously found Eap to have pro-inflammatory activity, and here show that purified native Eap triggered TNFα release in whole human blood in a dose-dependent manner. This level of TNFα increased adhesion of S. aureus to endothelial cells 4-fold via a mechanism involving protein A on the bacterial surface and gC1qR/p33 on the endothelial cell surface. The contribution this and other Eap activities play in disease severity during bacteraemia was tested by constructing an isogenic set of strains in which the eap gene was inactivated and complemented by inserting an intact copy elsewhere on the bacterial chromosome. Using a murine bacteraemia model we found that Eap expressing strains cause a more severe infection, demonstrating its role in invasive disease

Magnetic variation anomalies in northern England and southern Scotland

Single-station transfer functions linking the time variations of the vertical and horizontal components of the magnetic field at stations in northern England and southern Scotland have been compiled into a uniform data set. From hypothetical event analysis we show here that there are two distinct anomalies in the Borders region. One runs south-west to north-east, immediately to the south-east of the Southern Uplands Fault; the second follows the Northumberland Basin, and seems to exist because the conductive sedimentary rocks filling the basin create a link between the Irish and North Seas. If the Iapetus suture is marked by a conductivity anomaly, as has been suggested, these results place it beneath the Southern Uplands, unless it is masked by the surface conductor in the Northumberland Basin

The NRG1 gene is frequently silenced by methylation in breast cancers and is a strong candidate for the 8p tumour suppressor gene.

Neuregulin-1 (NRG1) is both a candidate oncogene and a candidate tumour suppressor gene. It not only encodes the heregulins and other mitogenic ligands for the ERBB family, but also causes apoptosis in NRG1-expressing cells. We found that most breast cancer cell lines had reduced or undetectable expression of NRG1. This included cell lines that had translocation breaks in the gene. Similarly, expression in cancers was generally comparable to or less than that in various normal breast samples. Many non-expressing cell lines had extensive methylation of the CpG island at the principal transcription start site at exon 2 of NRG1. Expression was reactivated by demethylation. Many tumours also showed methylation, whereas normal mammary epithelial fragments had none. Lower NRG1 expression correlated with higher methylation. Small interfering RNA (siRNA)-mediated depletion of NRG1 increased net proliferation in a normal breast cell line and a breast cancer cell line that expressed NRG1. The short arm of chromosome 8 is frequently lost in epithelial cancers, and NRG1 is the most centromeric gene that is always affected. NRG1 may therefore be the major tumour suppressor gene postulated to be on 8p: it is in the correct location, is antiproliferative and is silenced in many breast cancers

Geographies of science and technology 1:Boundaries and crossings

In a world of accelerating environmental crises, global pandemics and seemingly unstoppable datafication of anything that moves, thinks or feels, the politics of science and technology are pervasive. In this first of three progress reports on the geographies of science and technology, I home in on some definitional questions which an account of anything like a new or emerging subfield must necessarily concern itself. I examine how geographers have addressed the spatial effects of the making and unmaking of boundaries between science, technology and their various outsides. While work on historical and contemporary geographies of technoscience has often pulled in slightly different directions, I identify some promising convergences around questions of political economy and on the topic of scale as an emergent property of technoscientific practices. New attention is also falling on the spatial practices through which technoscience gets plugged into wider worlds, such as politics and policymaking, while geographers have also been busy disrupting, in a more experimental mode, conventional boundaries and hierarchies of technoscientific practice. Finally, the report examines recent and welcome efforts to convene new conversations around the geography of technology but cautions against the potential seduction of the new, the innovative and the ‘disruptive’. Important recent work in cultural geography has purposively unsettled assumed hierarchies of ‘high’ and ‘low’ tech, new and old, and suggests that any nascent subfield of ‘geography of technology’ needs to reflexively attend to how boundaries get drawn around ‘technology’, and with what effects