Downscaling regional climate model outputs for the Caribbean using a weather generator

Locally relevant scenarios of daily weather variables that represent the best knowledge of the present climate and projections of future climate change are needed by planners and managers to inform management and adaptation to climate change decisions. Information of this kind for the future is only readily available for a few developed country regions of the world. For many less-developed regions, it is often difficult to find series of observed daily weather data to assist in planning decisions. This study applies a previously developed single-site weather generator (WG) to the Caribbean, using examples from Belize in the west to Barbados in the east. The purpose of this development is to provide users in the region with generated sequences of possible future daily weather that they can use in a number of impact sectors. The WG is first calibrated for a number of sites across the region and the goodness of fit of the WG against the daily station observations assessed. Particular attention is focussed on the ability of the precipitation component of the WG to generate realistic extreme values for the calibration or control period. The WG is then modified using change factors (CFs) derived from regional climate model projections (control and future) to simulate future 30-year scenarios centred on the 2020s, 2050s and 2080s. Changes between the control period and the three futures are illustrated not just by changes in average temperatures and precipitation amounts but also by a number of well-used measures of extremes (very warm days/nights, the heaviest 5-day precipitation total in a month, counts of the number of precipitation events above specific thresholds and the number of consecutive dry days)

Application of a stochastic weather generator to assess climate change impacts in a semi-arid climate: The Upper Indus Basin

Assessing local climate change impacts requires downscaling from Global Climate Model simulations. Here, a stochastic rainfall model (RainSim) combined with a rainfall conditioned weather generator (CRU WG) have been successfully applied in a semi-arid mountain climate, for part of the Upper Indus Basin (UIB), for point stations at a daily time-step to explore climate change impacts. Validation of the simulated time-series against observations (1961–1990) demonstrated the models’ skill in reproducing climatological means of core variables with monthly RMSE of <2.0 mm for precipitation and ⩽0.4 °C for mean temperature and daily temperature range. This level of performance is impressive given complexity of climate processes operating in this mountainous context at the boundary between monsoonal and mid-latitude (westerly) weather systems. Of equal importance the model captures well the observed interannual variability as quantified by the first and last decile of 30-year climatic periods. Differences between a control (1961–1990) and future (2071–2100) regional climate model (RCM) time-slice experiment were then used to provide change factors which could be applied within the rainfall and weather models to produce perturbed ‘future’ weather time-series. These project year-round increases in precipitation (maximum seasonal mean change:+27%, annual mean change: +18%) with increased intensity in the wettest months (February, March, April) and year-round increases in mean temperature (annual mean +4.8 °C). Climatic constraints on the productivity of natural resource-dependent systems were also assessed using relevant indices from the European Climate Assessment (ECA) and indicate potential future risk to water resources and local agriculture. However, the uniformity of projected temperature increases is in stark contrast to recent seasonally asymmetrical trends in observations, so an alternative scenario of extrapolated trends was also explored. We conclude that interannual variability in climate will continue to have the dominant impact on water resources management whichever trajectory is followed. This demonstrates the need for sophisticated downscaling methods which can evaluate changes in variability and sequencing of events to explore climate change impacts in this region

Severity of Visual Field Loss at First Presentation to Glaucoma Clinics in England and Tanzania

Purpose: To compare severity of visual field (VF) loss at first presentation in glaucoma clinics in England and Tanzania. Methods: Large archives of VF records from automated perimetry were used to retrospectively examine vision loss at first presentation in glaucoma clinics in Tanzania (N = 1,502) and England (N = 9,264). Mean deviation (MD) of the worse eye at the first hospital visit was used as an estimate of detectable VF loss severity. Results: In Tanzania, 44.7% {CI95%: 42.2, 47.2} of patients presented with severe VF loss (< −20 dB), versus 4.6% {4.1, 5.0} in England. If we consider late presentation to also include cases of advanced loss (-12.01 dB to -20 dB), then the proportion of patients presenting late was 58.1% {55.6, 60.6} and 14.0% {13.3, 14.7}, respectively. The proportion of late presentations was greater in Tanzania at all ages, but the difference was particularly pronounced among working-age adults, with 50.3% {46.9, 53.7} of 18–65-year-olds presenting with advanced or severe VF loss, versus 10.2% {9.3, 11.3} in England. In both countries, men were more likely to present late than women. Conclusions: Late presentation of glaucoma is a problem in England, and an even greater challenge in Tanzania. Possible solutions are discussed, including increased community eye-care, and a more proactive approach to case finding through the use of disruptive new technologies, such as low-cost, portable diagnostic aids

Evaluation of semantic web ontologies for modelling art collections

© 2017, Springer International Publishing AG. The need for organising, sharing and digitally processing Cultural Heritage (CH) information has led to the development of formal knowledge representation models (ontologies) for the CH domain. Based on RDF and OWL, the standard data model and ontology language of the Semantic Web, ontologies such as CIDOC-CRM, the Europeana Data Model and VRA, offer enhanced representation capabilities, but also support for inference, querying and interlinking through the Web. This paper presents the results of a small-scale evaluation of the three most commonly used CH ontologies, with respect to their capacity to fulfil the data modelling requirements of art collections

Soluble FLT1 sensitizes endothelial cells to inflammatory cytokines by antagonizing VEGF receptor-mediated signalling.

AIMS: Pre-eclampsia affects 5-7% of pregnancies, and is a major cause of maternal and foetal death. Elevated serum levels of placentally derived splice variants of the vascular endothelial growth factor (VEGF) receptor, soluble fms-like tyrosine kinase-1 (sFLT1), are strongly implicated in the pathogenesis but, as yet, no underlying mechanism has been described. An excessive inflammatory-like response is thought to contribute to the maternal endothelial cell dysfunction that characterizes pre-eclampsia. We hypothesized that sFLT1 antagonizes autocrine VEGF-A signalling, rendering endothelial cells more sensitive to pro-inflammatory factors also released by the placenta. We tested this by manipulating VEGF receptor signalling and treating endothelial cells with low doses of tumour necrosis factor-α (TNF-α). METHODS AND RESULTS: Application of recombinant sFLT1 alone did not activate human umbilical vein endothelial cells (HUVECs). However, antagonizing the autocrine actions of endothelial VEGF-A and/or placenta growth factor (PlGF) by pre-incubation with recombinant sFLT1, anti-FLT1, anti-VEGF receptor 2 (KDR), anti-VEGF-A, VEGF receptor tyrosine kinase inhibitor SU5614, or knocking-down FLT1 or KDR transcripts rendered cells more sensitive to low doses of TNF-α. Each treatment increased activation, as measured by increases in endothelial intercellular adhesion molecule 1 (ICAM1), vascular cell adhesion molecule 1 (VCAM1), endothelin 1 (ET-1), von Willebrand factor (vWF), and leucocyte adhesion, and led to reduction in AKT Ser⁴⁷³ and endothelial nitric oxide synthase (eNOS) Ser¹¹⁷⁷ phosphorylation. CONCLUSIONS: Our data describe a mechanism by which sFLT1 sensitizes endothelial cells to pro-inflammatory factors, providing an explanation for how placental stress may precipitate the pre-eclamptic syndrome

Finding co-solvers on Twitter, with a little help from Linked Data

In this paper we propose a method for suggesting potential collaborators for solving innovation challenges online, based on their competence, similarity of interests and social proximity with the user. We rely on Linked Data to derive a measure of semantic relatedness that we use to enrich both user profiles and innovation problems with additional relevant topics, thereby improving the performance of co-solver recommendation. We evaluate this approach against state of the art methods for query enrichment based on the distribution of topics in user profiles, and demonstrate its usefulness in recommending collaborators that are both complementary in competence and compatible with the user. Our experiments are grounded using data from the social networking service Twitter.com

Observations and radiative transfer modelling of a massive dense cold core in G333

Cold massive cores are one of the earliest manifestations of high mass star formation. Following the detection of SiO emission from G333.125-0.562, a cold massive core, further investigations of the physics, chemistry and dynamics of this object has been carried out. Mopra and NANTEN2 molecular line profile observations, Australia Telescope Compact Array (ATCA) line and continuum emission maps, and Spitzer 24 and 70 \mum images were obtained. These new data further constrain the properties of this prime example of the very early stages of high mass star formation. A model for the source was constructed and compared directly with the molecular line data using a 3D molecular line transfer code - MOLLIE. The ATCA data reveal that G333.125-0.562 is composed of two sources. One of the sources is responsible for the previously detected molecular outflow and is detected in the Spitzer 24 and 70 \mum band data. Turbulent velocity widths are lower than other more active regions of G333 which reflects the younger evolutionary stage and/or lower mass of this core. The molecular line modelling requires abundances of the CO isotopes that strongly imply heavy depletion due to freeze-out of this species onto dust grains. The principal cloud is cold, moderately turbulent and possesses an outflow which indicates the presence of a central driving source. The secondary source could be an even less evolved object as no apparent associations with continuum emissions at (far-)infrared wavelengths.Comment: 10 pages, accepted to MNRA

Spectroscopic Abundances of Solar-Type Dwarfs in the Open Cluster M34 (NGC 1039)

Parameters and relative abundances of Fe, Ni, Ti, Cr, Ca, Si, Al, and Mg have been derived for nine M34 G and K dwarfs from high-resolution, modest signal-to-noise ratio Keck HIRES spectra. Effective temperatures have been derived spectroscopically and fall in the range 4750 K Teff 6130 K. Despite modest scatter in Fe, Ti, Cr, Ca, Al, and Mg (none of which is found to be correlated with Li scatter in M34), our two coolest stars are slightly though consistently underabundant in these elements relative to the warmer stars. The two cool stars are slightly overabundant in Si, whose abundances are derived from higher excitation lines. This and our finding that Fe ii–based abundances are significantly higher than Fe i–based values in the cool stars seem to point toward the action of non-LTE effects (overionization, overexcitation, or both), though additional analysis is required to exclude inadequacies in the model atmospheres. Final mean cluster abundances are based on five warm stars, which indicate [Fe/H] = +0.07 Æ0.04, and are void of any statistically significant scatter. The other elements scale well with Fe except for Ni, which appears to be slightly underabundant with respect to Fe. Potassium abundances are derived and show a surprising marked trend with temperature, which further supports our suspicion of the presence of non-LTE effects. Moreover, similar trends with temperature suggest that the Li and K underabundances in cool M34 dwarfs are partially related; thus, some portion of the well-known Li-Teff trend in cool M34 dwarfs may be illusory