3,578 research outputs found
Large-area functionalized CVD graphene for work function matched transparent electrodes
PublishedArticleThe efficiency of flexible photovoltaic and organic light emitting devices is heavily dependent on the availability of flexible and transparent conductors with at least a similar workfunction to that of Indium Tin Oxide. Here we present the first study of the work function of large area (up to 9 cm2) FeCl3 intercalated graphene grown by chemical vapour deposition on Nickel, and demonstrate values as large as 5.1 eV. Upon intercalation, a charge density per graphene layer of 5 ⋅ 1013 ± 5 ⋅ 1012 cm−2 is attained, making this material an attractive platform for the study of plasmonic excitations in the infrared wavelength spectrum of interest to the telecommunication industry. Finally, we demonstrate the potential of this material for flexible electronics in a transparent circuit on a polyethylene naphthalate substrate.EPSRCRoyal Society international Exchanges Schem
Characterisation of gas reference materials for underpinning atmospheric measurements of stable isotopes of nitrous oxide
The precise measurement of the amount fraction of atmospheric
nitrous oxide (N2O) is required to understand global emission trends.
Analysis of the site-specific stable isotopic composition of N2O
provides a means to differentiate emission sources. The availability of
accurate reference materials of known N2O amount fractions and isotopic
composition is critical for achieving these goals. We present the
development of nitrous oxide gas reference materials for underpinning
measurements of atmospheric composition and isotope ratio. Uncertainties
target the World Metrological Organisation Global Atmosphere Watch (WMO-GAW) compatibility goal of 0.1 nmol mol−1 and extended compatibility goal of
0.3 nmol mol−1, for atmospheric N2O measurements in an amount
fraction range of 325–335 nmol mol−1. We also demonstrate the stability
of amount fraction and isotope ratio of these reference materials and
present a characterisation study of the cavity ring-down spectrometer used
for analysis of the reference materials.</p
Long-term workforce participation patterns following head and neck cancer
© 2014, Springer Science+Business Media New York. Purpose: This analysis describes the long-term workforce participation patterns of individuals diagnosed with head and neck cancer (HNC). Methods: Survivors of HNC (ICD10 C00-C14, C32) diagnosed at least 8 months previously were identified from the National Cancer Registry Ireland and sent a survey including questions about working arrangements before and since diagnosis. Descriptive statistics and multivariate logistic regression were used to examine the factors that influence workforce participation at 0, 1 and 5 years after diagnosis. Results: Two hundred sixty-four individuals employed at the time of diagnosis responded to the survey, an average 6 years post-diagnosis. Seventy-seven percent took time off work after diagnosis, with a mean work absence of 9 months (range 0–65 months). Fifty-two percent of participants reduced their working hours (mean reduction 15 h/week). The odds of workforce participation following HNC were increased by not being eligible for free medical care (OR 2.61, 95 % CI 1.15–5.94), having lip, mouth or salivary gland cancer (compared to cancer of the pharynx or cancer of the larynx, OR 2.79, 1.20–6.46), being self-employed (OR 2.01, 1.07–3.80), having private health insurance (OR 2.06, 1.11–3.85) and not receiving chemotherapy (OR 2.82, 1.31–6.06). After 5 years, only the effect of medical card remained (i.e., medical insurance) (OR 4.03, 1.69–9.62). Conclusions: Workforce participation patterns after HNC are complex and are influenced by cancer, treatment and employment factors. Implications for Cancer Survivors: Patients should be informed of the potential impacts of HNC on workforce participation, and clinicians, policy makers and employers should be aware of these potential longer-term effects and related variables
Climate change, climatic variation and extreme biological responses
Extreme climatic events could be major drivers of biodiversity change, but it is unclear whether extreme biological changes are (i) individualistic (species- or group-specific), (ii) commonly associated with unusual climatic events and/or (iii) important determinants of long-term population trends. Using population time series for 238 widespread species (207 Lepidoptera and 31 birds) in England since 1968, we found that population 'crashes' (outliers in terms of species' year-to-year population changes) were 46% more frequent than population 'explosions'. (i) Every year, at least three species experienced extreme changes in population size, and in 41 of the 44 years considered, some species experienced population crashes while others simultaneously experienced population explosions. This suggests that, even within the same broad taxonomic groups, species are exhibiting individualistic dynamics, most probably driven by their responses to different, short-term events associated with climatic variability. (ii) Six out of 44 years showed a significant excess of species experiencing extreme population changes (5 years for Lepidoptera, 1 for birds). These 'consensus years' were associated with climatically extreme years, consistent with a link between extreme population responses and climatic variability, although not all climatically extreme years generated excess numbers of extreme population responses. (iii) Links between extreme population changes and long-term population trends were absent in Lepidoptera and modest (but significant) in birds. We conclude that extreme biological responses are individualistic, in the sense that the extreme population changes of most species are taking place in different years, and that long-term trends of widespread species have not, to date, been dominated by these extreme changes.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'
Conducting robust ecological analyses with climate data
Although the number of studies discerning the impact of climate change on ecological systems continues to increase, there has been relatively little sharing of the lessons learnt when accumulating this evidence. At a recent workshop entitled ‘Using climate data in ecological research’ held at the UK Met Office, ecologists and climate scientists came together to discuss the robust analysis of climate data in ecology. The discussions identified three common pitfalls encountered by ecologists: 1) selection of inappropriate spatial resolutions for analysis; 2) improper use of publically available data or code; and 3) insufficient representation of the uncertainties behind the adopted approach. Here, we discuss how these pitfalls can be avoided, before suggesting ways that both ecology and climate science can move forward. Our main recommendation is that ecologists and climate scientists collaborate more closely, on grant proposals and scientific publications, and informally through online media and workshops. More sharing of data and code (e.g. via online repositories), lessons and guidance would help to reconcile differing approaches to the robust handling of data. We call on ecologists to think critically about which aspects of the climate are relevant to their study system, and to acknowledge and actively explore uncertainty in all types of climate data. And we call on climate scientists to make simple estimates of uncertainty available to the wider research community. Through steps such as these, we will improve our ability to robustly attribute observed ecological changes to climate or other factors, while providing the sort of influential, comprehensive analyses that efforts to mitigate and adapt to climate change so urgently require
A ‘quiet revolution’? The impact of Training Schools on initial teacher training partnerships
This paper discusses the impact on initial teacher training of a new policy initiative in England: the introduction of Training Schools. First, the Training School project is set in context by exploring the evolution of a partnership approach to initial teacher training in England. Ways in which Training Schools represent a break with established practice are considered together with their implications for the dominant mode of partnership led by higher education institutions (HEIs). The capacity of Training Schools to achieve their own policy objectives is examined, especially their efficacy as a strategy for managing innovation and the dissemination of innovation. The paper
ends by focusing on a particular Training School project which has adopted an unusual approach to its work and enquires whether this alternative approach could offer a more profitable way forward. During the course of the paper, five different models of partnership are considered:
collaborative, complementary, HEI-led, school-led and partnership within a partnership
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The effectiveness of protected areas in the conservation of species with changing geographical ranges
A cornerstone of conservation is the designation and management of protected areas (PAs): locations often under conservation management containing species of conservation concern, where some development and other detrimental influences are prevented or mitigated. However, the value of PAs for conserving biodiversity in the long term has been questioned given that species are changing their distributions in response to climatic change. There is a concern that PAs may become climatically unsuitable for those species that they were designated to protect, and may not be located appropriately to receive newly-colonizing species for which the climate is improving. In the present study, we analyze fine-scale distribution data from detailed resurveys of seven butterfly and 11 bird species in Great Britain aiming to examine any effect of PA designation in preventing extinctions and promoting colonizations. We found a positive effect of PA designation on species' persistence at trailing-edge warm range margins, although with a decreased magnitude at higher latitudes and altitudes. In addition, colonizations by range expanding species were more likely to occur on PAs even after altitude and latitude were taken into account. PAs will therefore remain an important strategy for conservation. The potential for PA management to mitigate the effects of climatic change for retracting species deserves further investigation
The impacts of environmental warming on Odonata: a review
Climate change brings with it unprecedented rates of increase in environmental temperature, which will have major consequences for the earth's flora and fauna. The Odonata represent a taxon that has many strong links to this abiotic factor due to its tropical evolutionary history and adaptations to temperate climates. Temperature is known to affect odonate physiology including life-history traits such as developmental rate, phenology and seasonal regulation as well as immune function and the production of pigment for thermoregulation. A range of behaviours are likely to be affected which will, in turn, influence other parts of the aquatic ecosystem, primarily through trophic interactions. Temperature may influence changes in geographical distributions, through a shifting of species' fundamental niches, changes in the distribution of suitable habitat and variation in the dispersal ability of species. Finally, such a rapid change in the environment results in a strong selective pressure towards adaptation to cope and the inevitable loss of some populations and, potentially, species. Where data are lacking for odonates, studies on other invertebrate groups will be considered. Finally, directions for research are suggested, particularly laboratory studies that investigate underlying causes of climate-driven macroecological patterns
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