2,385 research outputs found
Social Sensing of Floods in the UK
"Social sensing" is a form of crowd-sourcing that involves systematic
analysis of digital communications to detect real-world events. Here we
consider the use of social sensing for observing natural hazards. In
particular, we present a case study that uses data from a popular social media
platform (Twitter) to detect and locate flood events in the UK. In order to
improve data quality we apply a number of filters (timezone, simple text
filters and a naive Bayes `relevance' filter) to the data. We then use place
names in the user profile and message text to infer the location of the tweets.
These two steps remove most of the irrelevant tweets and yield orders of
magnitude more located tweets than we have by relying on geo-tagged data. We
demonstrate that high resolution social sensing of floods is feasible and we
can produce high-quality historical and real-time maps of floods using Twitter.Comment: 24 pages, 6 figure
CoRe: A way to build pedagogical content knowledge for beginning teachers
Research has shown that one of the factors which enables teachers to be effective is their rich pedagogical content knowledge (PCK). Beginning teachers need support to develop this PCK and recent research in the field has proposed a conceptual tool known as âcontent representationsâ, or CoRes, as a model for doing this. The study reported here brought together science and technology experts in content and pedagogy, early career secondary teachers, and researchers to design a CoRe to assist development of teacher PCK. The study then researched the early career teachersâ use of the CoRe in their planning and delivery of a unit in their classrooms to examine the effect of the CoRe on teaching and learning, and on the development of the teachersâ PCK
Mapping biodiversity value worldwide: combining higher-taxon richness from different groups
Maps of large-scale biodiversity are urgently needed to guide conservation, and yet complete enumeration of organisms is impractical at present. One indirect approach is to measure richness at higher taxonomic ranks, such as families. The difficulty is how to combine information from different groups on numbers of higher taxa, when these taxa may in effect have been defined in different ways, particularly for more distantly related major groups. In this paper, the regional family richness of terrestrial and freshwater seed plants, amphibians, reptiles and mammals is mapped worldwide by combining: (i) absolute family richness; (ii) proportional family richness; and (iii) proportional family richness weighted for the total species richness in each major group. The assumptions of the three methods and their effects on the results are discussed, although for these data the broad pattern is surprisingly robust with respect to the method of combination. Scores from each of the methods of combining families are used to rank the top five richness hotspots and complementary areas, and hotspots of endemism are mapped by unweighted combination of range-size rarity scores
Analysis of self-oscillating DC-DC resonant power converters using a hysteretic relay
The paper presents a technique for exciting resonant DC-DC converters in a self-oscillating manner. The analysis necessary to predict the behaviour of such converters is also given. The oscillation is based on the behaviour of a hysteretic relay with a negative hysteresis transition. Self-oscillating converters benefit from higher efficiency/higher power density than their non-self-oscillating counterparts as they can be operated closer to the tank resonant frequency. The self-oscillating mechanism presented here is also simple and cost effective to implement. A prototype converter is presented in order to verify the theoretical claims
Stress exposure results in increased peroxisomal levels of yeast Pnc1 and Gpd1, which are imported via a piggy-backing mechanism
AbstractSaccharomyces cerevisiae glycerol phosphate dehydrogenase 1 (Gpd1) and nicotinamidase (Pnc1) are two stress-induced enzymes. Both enzymes are predominantly localised to peroxisomes at normal growth conditions, but were reported to localise to the cytosol and nucleus upon exposure of cells to stress. Import of both proteins into peroxisomes depends on the peroxisomal targeting signal 2 (PTS2) receptor Pex7. Gpd1 contains a PTS2, however, Pnc1 lacks this sequence.Here we show that Pnc1 physically interacts with Gpd1, which is required for piggy-back import of Pnc1 into peroxisomes. Quantitative fluorescence microscopy analyses revealed that the levels of both proteins increased in peroxisomes and in the cytosol upon exposure of cells to stress. However, upon exposure of cells to stress we also observed enhanced cytosolic levels of the control PTS2 protein thiolase, when produced under control of the GPD1 promoter. This suggests that these conditions cause a partial defect in PTS2 protein import, probably because the PTS2 import pathway is easily saturated
An N-terminal alpha-Synuclein fragment binds lipid vesicles to modulate lipid induced aggregation
Misfolding and aggregation of alpha-synuclein (αS) into toxic conformations is involved in numerous neurodegenerative diseases. In Parkinson's disease (PD), this occurs within dopaminergic neurons, causing cell death and disease symptoms. During αS aggregation, many protein-protein interactions (PPIs) form over broad and flat protein surfaces, limiting potential for small-molecule intervention. Peptides, however, harbor great therapeutic promise since they can selectively engage with and modulate the large surface areas involved yet are small enough to function as druggable agents if suitably structured. Here, we explore the first 25 residues of αS (αS 1â25) as a template for peptide-based αS aggregation antagonists. We report that αS 1â25 inhibits lipid-induced αS aggregation in a dose-dependent manner. αS 1â25 functions by binding to lipids to prevent αS binding, with both αS and peptide requiring lipid for inhibition to occur. These findings present a potential mechanistic route for the treatment or prevention of PD.</p
Phosphorylation of Pex11p does not regulate peroxisomal fission in the yeast Hansenula polymorpha
Pex11p plays a crucial role in peroxisomal fission. Studies in Saccharomyces cerevisiae and Pichia pastoris indicated that Pex11p is activated by phosphorylation, which results in enhanced peroxisome proliferation. In S. cerevisiae but not in P. pastoris, Pex11p phosphorylation was shown to regulate the protein's trafficking to peroxisomes. However, phosphorylation of PpPex11p was proposed to influence its interaction with Fis1p, another component of the organellar fission machinery. Here, we have examined the role of Pex11p phosphorylation in the yeast Hansenula polymorpha. Employing mass spectrometry, we demonstrate that HpPex11p is also phosphorylated on a Serine residue present at a similar position to that of ScPex11p and PpPex11p. Furthermore, through the use of mutants designed to mimic both phosphorylated and unphosphorylated forms of HpPex11p, we have investigated the role of this post-translational modification. Our data demonstrate that mutations to the phosphorylation site do not disturb the function of Pex11p in peroxisomal fission, nor do they alter the localization of Pex11p. Also, no effect on peroxisome inheritance was observed. Taken together, these data lead us to conclude that peroxisomal fission in H. polymorpha is not modulated by phosphorylation of Pex11p.</p
Electro-kinetic technology as a low-cost method for dewatering food by-product
Increasing volumes of food waste, intense environmental awareness, and stringent legislation have imposed increased demands upon conventional food waste management. Food byproducts that were once considered to be without value are now being utilized as reusable materials, fuels, and energy in order to reduce waste. One major barrier to the valorization of food by-products is their high moisture content. This has brought about the necessity of dewatering food waste for any potential re-use for certain disposal options. A laboratory system for experimentally characterizing electro-kinetic dewatering of food by-products was evaluated. The bench scale system, which is an augmented filter press, was used to investigate the dewatering at constant voltage. Five food by-products (brewerâs spent grain, cauliflower trimmings, mango peel, orange peel, and melon peel) were studied. The results indicated that electro-kinetic dewatering combined with mechanical dewatering can reduce the percentage of moisture from 78% to 71% for brewerâs spent grain, from 77% to 68% for orange peel, from 80% to 73% for mango peel, from 91% to 74% for melon peel, and from 92% to 80% for cauliflower trimmings. The total moisture reduction showed a correlation with electrical conductivity (R2ÂŒ0.89). The energy consumption of every sample was evaluated and was found to be up to 60 times more economical compared to thermal processing
BEAT-IT:comparing a behavioural activation treatment for depression in adults with intellectual disabilities with an attention control : study protocol for a randomised controlled trial
BACKGROUND: Depression appears to be more enduring amongst people with intellectual disabilities, suggesting that it is a more chronic problem or more poorly managed in this population. This is not helped by a lack of evidence about the effectiveness of psychological therapies for people who have intellectual disabilities and depression. Behavioural activation, which aims to counteract depression by increasing individuals' level of meaningful activity and their exposure to positive reinforcers, has proven to be as effective as cognitive behavioural therapy in the general population. Given that this therapy makes fewer communicative demands and focuses on activity, it was thought that behavioural activation would be both accessible and apt for people with intellectual disabilities, who are often socially marginalised. METHODS/DESIGN: This study is a multi-centre single-blind randomised controlled trial of behavioural activation versus a self-help attention control intervention for depression in adults with mild/moderate intellectual disabilities. The study has an internal pilot in one centre, to establish that recruitment can be built up and sustained at the required level, before being rolled out across the other sites. One hundred sixty-six participants will be randomly assigned to the behavioural activation or self-help interventions, which will be delivered to individuals with mild to moderate intellectual disabilities, accompanied by someone who provides them with regular support. Both interventions are manualised and will be delivered over a period of approximately 4 months. The primary outcome measure will be the Glasgow Depression Scale, a self-report measure which is completed at baseline and 4 and 12 months post-randomisation. Secondary outcomes include measures of participants' activity levels, proxy reports of depressive symptoms, and cost-effectiveness. DISCUSSION: The study will provide evidence about the effectiveness of behavioural activation for depression, adapted for people who have mild/moderate intellectual disabilities, and will inform the delivery of psychological therapies to people with intellectual disabilities in practice. TRIAL REGISTRATION: Date trial registered: Nov. 13, 2012; trial registration number: ISRCTN 09753005
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