520 research outputs found
Starting a Private Foundation: Carrying Out the Donor's Intent
A beginners guide to setting up a private foundation, this report is designed to provide the reader with a general insight into the world of philanthropy and specific observations about private foundations. Topics covered include: charitable giving in general, defining and carrying out your mission, determining the structure of your foundation and how to begin the foundation. Full content listing is provided
Microarray experiments: Considerations for experimental design
Microarrays are useful tools to investigate the expression of thousands of genes rapidly. Some researchers remain reluctant to use the technology, however, largely because of its expense. Careful design of a microarray experiment is key to generating cost-effective results. This article explores issues that researchers face when embarking on a microarray experiment for the first time. These include decisions about which microarray platform is available for the organism of interest, the degree of replication (biological and technical) needed and which design (direct or indirect, loop or balanced block) is suitable
A meiosis-specific Spt5 homolog involved in non-coding transcription
Spt5 is a conserved and essential transcriptional regulator that binds directly to RNA polymerase and is involved in transcription elongation, polymerase pausing and various co-transcriptional processes. To investigate the role of Spt5 in non-coding transcription, we used the unicellular model Paramecium tetraurelia. In this ciliate, development is controlled by epigenetic mechanisms that use different classes of non-coding RNAs to target DNA elimination. We identified two SPT5 genes. One (STP5v) is involved in vegetative growth, while the other (SPT5m) is essential for sexual reproduction. We focused our study on SPT5m, expressed at meiosis and associated with germline nuclei during sexual processes. Upon Spt5m depletion, we observed absence of scnRNAs, piRNA-like 25 nt small RNAs produced at meiosis. The scnRNAs are a temporal copy of the germline genome and play a key role in programming DNA elimination. Moreover, Spt5m depletion abolishes elimination of all germline-limited sequences, including sequences whose excision was previously shown to be scnRNA-independent. This suggests that in addition to scnRNA production, Spt5 is involved in setting some as yet uncharacterized epigenetic information at meiosis. Our study establishes that Spt5m is crucial for developmental genome rearrangements and necessary for scnRNA production
Integration-free reprogramming of lamina propria progenitor cells
Producing induced pluripotent stem cells (iPSCs) from human tissue for use in personalized medicine strategies or therapeutic testing is at the forefront of medicine. Therefore, identifying a source of cells to reprogram that is easily accessible via a simple noninvasive procedure is of great clinical importance. Reprogramming these cells to iPSCs through nonintegrating methods for genetic manipulation is paramount for regenerative purposes. Here, we demonstrate reprogramming of oral mucosal lamina propria progenitor cells from patients undergoing routine dental treatment. Reprogramming was performed utilizing nonintegrating plasmids containing all 6 pluripotency genes (OCT4, SOX2, KLF4, NANOG, LIN28, and cMYC). Resulting iPSCs lacked genetic integration of the vector genes and had the ability to differentiate down mesoderm, ectoderm, and endoderm lineages, demonstrating pluripotency. In conclusion, oral mucosal lamina propria progenitor cells represent a source of cells that can be obtained with minimal invasion, as they can be taken concurrently with routine treatments. The resulting integration-free iPSCs therefore have great potential for use in personalized medicine strategies
R/BHC: fast Bayesian hierarchical clustering for microarray data
BACKGROUND: Although the use of clustering methods has rapidly become one of the standard computational approaches in the literature of microarray gene expression data analysis, little attention has been paid to uncertainty in the results obtained. RESULTS: We present an R/Bioconductor port of a fast novel algorithm for Bayesian agglomerative hierarchical clustering and demonstrate its use in clustering gene expression microarray data. The method performs bottom-up hierarchical clustering, using a Dirichlet Process (infinite mixture) to model uncertainty in the data and Bayesian model selection to decide at each step which clusters to merge. CONCLUSION: Biologically plausible results are presented from a well studied data set: expression profiles of A. thaliana subjected to a variety of biotic and abiotic stresses. Our method avoids several limitations of traditional methods, for example how many clusters there should be and how to choose a principled distance metric
FAIRMODE: A FORUM FOR AIR QUALITY MODELLING IN EUROPE
FAIRMODE (Forum for AIR quality MODelling in Europe) is an air quality modelling network that was established as a
joint initiative of the European Environment Agency (EEA) and European Commissionâs Joint Research Centre (JRC). In a
common effort EEA and JRC aim at responding to the requirements of the new Air Quality Directive, with particular focus on the
introduction of modelling as a necessary tool for air quality assessment and air quality management. The main aim of the modelling
network is to bring together air quality modellers and model users in order to promote and support harmonised use of modelling for
the assessment of air quality by EU and EEA member countries. The network will thus encourage synergy â at a local, national and
European level - through the development and implementation of a common infrastructure based on best practices for reporting and
storing information relevant to air quality modelling. A major objective of the FAIRMODE initiative is to provide guidance to
present and future air quality model users in EEAâs EIONET partnership network. FAIRMODE also aims to enhance awareness of
model usefulness, reliability and accuracy through model validation and intercomparison exercises at a national or European level.
The JRC has taken on a leading role in the co-ordination of the latter activities gaining from its experience in leading the
âEurodeltaâ and âCityDeltaâ intercomparison exercises.
A centralised web portal has been created in support of FAIRMODE, which is currently being used for internal communication
purposes of the network participants, but will also provide the means for exchange of relevant material and experiences between all
interested modellers and model users. The initial activities of the network will be organised by two main Work Groups, focusing on
the preparation of a Guidance Document for model use and on model QA/QC procedures (input data, other uncertainties)
respectively. The progress of the preparation of these documents as well as of the rest of the regular activities of the network will be
reviewed and discussed within the frame of annual Plenary meetings and Steering Committee meetings
Neural Filters for Jet Analysis
We study the efficiency of a neural-net filter and deconvolution method for
estimating jet energies and spectra in high-background reactions such as
nuclear collisions at the relativistic heavy-ion collider and the large hadron
collider. The optimal network is shown to be surprisingly close but not
identical to a linear high-pass filter. A suitably constrained deconvolution
method is shown to uncover accurately the underlying jet distribution in spite
of the broad network response. Finally, we show that possible changes of the
jet spectrum in nuclear collisions can be analyzed quantitatively, in terms of
an effective energy loss with the proposed method. {} {Dong D W and Gyulassy M
1993}{Neural filters for jet analysis}
{(LBL-31560) Physical Review E Vol~47(4) pp~2913-2922}Comment: 21 pages of Postscript, (LBL-31560
Road salt emissions: A comparison of measurements and modelling using the NORTRIP road dust emission model
AbstractDe-icing of road surfaces is necessary in many countries during winter to improve vehicle traction. Large amounts of salt, most often sodium chloride, are applied every year. Most of this salt is removed through drainage or traffic spray processes but a certain amount may be suspended, after drying of the road surface, into the air and will contribute to the concentration of particulate matter. Though some measurements of salt concentrations are available near roads, the link between road maintenance salting activities and observed concentrations of salt in ambient air is yet to be quantified. In this study the NORTRIP road dust emission model, which estimates the emissions of both dust and salt from the road surface, is applied at five sites in four Nordic countries for ten separate winter periods where daily mean ambient air measurements of salt concentrations are available. The model is capable of reproducing many of the salt emission episodes, both in time and intensity, but also fails on other occasions. The observed mean concentration of salt in PM10, over all ten datasets, is 4.2 Όg/m3 and the modelled mean is 2.8 Όg/m3, giving a fractional bias of â0.38. The RMSE of the mean concentrations, over all 10 datasets, is 2.9 Όg/m3 with an average R2 of 0.28. The mean concentration of salt is similar to the mean exhaust contribution during the winter periods of 2.6 Όg/m3. The contribution of salt to the kerbside winter mean PM10 concentration is estimated to increase by 4.1 ± 3.4 Όg/m3 for every kg/m2 of salt applied on the road surface during the winter season. Additional sensitivity studies showed that the accurate logging of salt applications is a prerequisite for predicting salt emissions, as well as good quality data on precipitation. It also highlights the need for more simultaneous measurements of salt loading together with ambient air concentrations to help improve model parameterisations of salt and moisture removal processes
Scoping Potential Routes to UK Civil Unrest via the Food System: Results of a Structured Expert Elicitation
We report the results of a structured expert elicitation to identify the most likely types of potential food system disruption scenarios for the UK, focusing on routes to civil unrest. We take a backcasting approach by defining as an end-point a societal event in which 1 in 2000 people have been injured in the UK, which 40% of experts rated as âPossible (20â50%)â, âMore likely than not (50â80%)â or âVery likely (>80%)â over the coming decade. Over a timeframe of 50 years, this increased to 80% of experts. The experts considered two food system scenarios and ranked their plausibility of contributing to the given societal scenario. For a timescale of 10 years, the majority identified a food distribution problem as the most likely. Over a timescale of 50 years, the experts were more evenly split between the two scenarios, but over half thought the most likely route to civil unrest would be a lack of total food in the UK. However, the experts stressed that the various causes of food system disruption are interconnected and can create cascading risks, highlighting the importance of a systems approach. We encourage food system stakeholders to use these results in their risk planning and recommend future work to support prevention, preparedness, response and recovery planning
Increased resistance to biotrophic pathogens in the Arabidopsis constitutive induced resistance 1 mutant is EDS1 and PAD4-dependent and modulated by environmental temperature
The Arabidopsis constitutive induced resistance 1 ( cir1 ) mutant displays salicylic acid (SA)-dependent constitutive expression of defence genes and enhanced resistance to biotrophic pathogens. To further characterise the role of CIR1 in plant immunity we conducted epistasis analyses with two key components of the SA-signalling branch of the defence network, ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) and PHYTOALEXIN DEFICIENT4 (PAD4). We demonstrate that the constitutive defence phenotypes of cir1 require both EDS1 and PAD4, indicating that CIR1 lies upstream of the EDS1-PAD4 regulatory node in the immune signalling network. In light of this finding we examined EDS1 expression in cir1 and observed increased protein, but not mRNA levels in this mutant, suggesting that CIR1 might act as a negative regulator of EDS1 via a post-transcriptional mechanism. Finally, as environmental temperature is known to influence the outcome of plant-pathogen interactions, we analysed cir1 plants grown at 18, 22 or 25°C. We found that susceptibility to Pseudomonas syringae pv. tomato ( Pst ) DC3000 is modulated by temperature in cir1 . Greatest resistance to this pathogen (relative to PR-1:LUC control plants) was observed at 18°C, while at 25°C no difference in susceptibility between cir1 and control plants was apparent. The increase in resistance to Pst DC3000 at 18°C correlated with a stunted growth phenotype, suggesting that activation of defence responses may be enhanced at lower temperatures in the cir1 mutant
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