A Corpus-Based Approach for Building Semantic Lexicons

Semantic knowledge can be a great asset to natural language processing systems, but it is usually hand-coded for each application. Although some semantic information is available in general-purpose knowledge bases such as WordNet and Cyc, many applications require domain-specific lexicons that represent words and categories for a particular topic. In this paper, we present a corpus-based method that can be used to build semantic lexicons for specific categories. The input to the system is a small set of seed words for a category and a representative text corpus. The output is a ranked list of words that are associated with the category. A user then reviews the top-ranked words and decides which ones should be entered in the semantic lexicon. In experiments with five categories, users typically found about 60 words per category in 10-15 minutes to build a core semantic lexicon.Comment: 8 pages - to appear in Proceedings of EMNLP-

Being Y-AP Savvy: A primer on creating & sustaining youth-adult partnerships

This manual is designed to help all those committed to youth-adult partnerships (Y-AP) acquire core knowledge, establish and communicate a point of view about Y-AP, and build consensus on key issues regarding Y-AP

A review of the leader approach for delivering the rural development programme for England: a report for Defra

This report, commissioned by the Rural Communities Policy Unit at Defra, sets out the findings of a review of the Leader approach in England. The focus of the review is the impact of Leader in contributing to the delivery of the Rural Development Programme (RDP) in England, in order to inform the future Leader approach to delivering rural policy. The research is primarily based on a review of existing literature and in-depth qualitative research with Local Action Groups and other stakeholders involved in delivering or benefiting from the Leader approach. The review focuses on four key issues: 1) Evidence to support the rationale for use of EU resources to enable rural development – justifying intervention for the current programme and informing choices about interventions in the next programme 2) Evidence on the extent to which interventions have been effective to date and where future resources can be targeted 3) Evidence to provide an assessment of the impact of RDPE spend (2007-13) on outcomes – with reference to delivery mechanisms 4) Evidence to support prioritisation of activities to be funded under the next programme mapped against the six EU wide priorities for 2014-2020 and inform decisions about future delivery models

LEADER as a vehicle for neo-endogenous rural development in England

LEADER emphasises neo-endogenous approaches where local rural development relies as much as possible on “bottom-up” activities. This research shows that the mainstreaming of LEADER saw certain compromises regarding the philosophical aspiration to give greater weight to local issues, local resources and local engagement. However, many LAGs learned to apply flexibility to meet local opportunities and challenges demonstrating how LEADER can empower local actors. Future challenges require LEADER to be more integrated with other rural policies and for the procedural elements to be simplified, especially for the smaller projects that have been found to make real impact at a very local level

Corpus-based bootstrapping algorithm for semi-automated semantic lexicon construction

Journal ArticleMany applications need a lexicon that represents semantic information but acquiring lexical information is time consuming. We present a corpus-based bootstrapping algorithm that assists users in creating domain-specifi c semantic lexicons quickly. Our algorithm uses a representative text corpus for the domain and a small set of 'seed words' that belong to a semantic class of interest. The algorithm hypothesizes new words that are also likely to belong to the semantic class because they occur in the same contexts as the seed words. The best hypotheses are added to the seed word list dynamically, and the process iterates in a bootstrapping fashion. When the bootstrapping process halts, a ranked list of hypothesized category words is presented to a user for review. We used this algorithm to generate a semantic lexicon for eleven semantic classes associated with the MUC-4 terrorism domain

Corpus-based approach for building semantic lexicons

Journal ArticleSemantic knowledge can be a great asset to natural language processing systems, but it is usually hand-coded for each application. Although some semantic information is available in general-purpose knowledge bases such as Word Net and Cyc, many applications require domain-specific lexicons that represent words and categories for a particular topic. In this paper, we present a corpus-based method that can be used t o build semantic lexicons for specific categories. The input t o the system is a small set of seed words for a category and a representative text corpus. The output is a ranked list of words that are associated with the category. A user then reviews the top-ranked words and decides which ones should be entered in the semantic lexicon. Tn experiments with five categories, users typically found about 60 words per category in 10-15 minutes to build a core semantic lexicon

Constraints on Light Majorana Dark Matter from Colliders

We explore model-independent collider constraints on light Majorana dark matter particles. We find that colliders provide a complementary probe of WIMPs to direct detection, and give the strongest current constraints on light DM particles. Collider experiments can access interactions not probed by direct detection searches, and outperform direct detection experiments by about an order of magnitude for certain operators in a large part of parameter space. For operators which are suppresssed at low momentum transfer, collider searches have already placed constraints on such operators limiting their use as an explanation for DAMA.Comment: 4 pages, 6 figure

Ochre and biochar: technologies for phosphorus capture and re-use

Despite recent instability in the global supply of phosphate-rock derived fertiliser and the potential for this to continue into the future, the recovery of phosphorus (P) from wastewater treatment systems, where P is abundant and accessible, is well below maximum potential. Considerable resource is spent on removing P from wastewater in order to comply with environmental standards and to protect aquatic ecosystems from eutrophication, yet there is little emphasis on capturing the P in a way that is optimised for re-using it as agricultural fertiliser. To address this lack of innovation in the face of climate change and food insecurity, a concept for a material capable of capturing P from wastewater was developed, with an emphasis on the utilisation of otherwise waste materials and the use of carbon neutral or negative production technologies. Based on the demonstrated P capture properties of coal minewater treatment waste (ochre) and biochar made from anaerobically digested feedstocks, a range of biochars were designed and produced using different mixtures of ochre (“OC”), sourced from the UK Coal Authority Minto minewater treatment scheme in Fife, Scotland and anaerobically digested sewage sludge (“AD”), sourced from the Newbridge wastewater treatment plant in Edinburgh. A first generation of materials consisting of either AD or a 1:1 mixture (dry weight basis) of OC and AD were produced in a small-scale batch pyrolysis unit at two pyrolysis highest treatment temperatures (HTTs) (450 and 550°C) to give the biochars AD450, AD550, OCAD450 and OCAD550. These were tested for their P capture properties in repeated P-exposure experiments with pH buffering in comparison to unpyrolysed ochre, activated carbon and a natural zeolite. After 5 days of repeated exposure to a P solution at a wastewater-relevant concentration (20 mg P l-1) replenished every 24 h, relatively high masses of P were recovered by ochre (1.73 ± 8.93×10-3 mg P g-1) and the biochars OCAD550 (1.26 ± 4.66×10-3 mg P g-1), OCAD450 (1.24 ± 2.10×10-3 mg P g-1), AD450 (1.06 ± 3.84×10-3 mg P g-1), and AD550 (0.986 ± 9.31×10-3 mg P g-1). The biochar materials had higher removal rates than both activated carbon (0.884 ± 1.69×10-2 mg P g-1) and zeolite (0.130 ± 1.05×10-2 mg P g-1). To assess the extractability of recovered P and thus potential plant bioavailability, P exposure was followed by repeated extraction of the materials for 4 days with pH 7-buffered deionised water. The AD biochars retained 55% of the P recovered, OCAD biochars 78% and ochre 100%. Assessment of potentially toxic element (PTE) concentrations in the biochars against guideline values indicated low risk associated with their use in the environment. A second generation of materials were produced to examine the scalability of the concept. Mixtures of AD and OC were pelletised with a lignin binder (89.1:9.9:1.0 ratio, dry weight basis) and AD was pelletised with binder (99:1 ratio, dry weight basis). The pelletised feedstocks were pyrolysed in a bench-scale continuous flow pyrolysis kiln at the same two HTTs to give the pelletised biochars PAD450, PAD550, POCAD450 and POCAD550. Analysis of digested biochar samples compared to the previous generation of biochars showed general similarities between the two groups, apart from the substantially lower Fe content. Sub-samples of the pelletised biochars were exposed to a 20 mg l-1 P solution over 6 days, with the solution replaced every 24 h to give the P-exposed biochars EPAD450, EPAD550, EPOCAD450 and EPOCAD550. To probe the mechanisms of P capture by these materials and how feedstock preparation and pyrolysis conditions affected these, spectroscopic analysis using laser-ablation (LA) ICP-MS, X-ray diffraction, X-ray photo-electron spectroscopy (XPS) and scanning electron microscopy coupled with energy dispersive X-ray was performed. The results highlighted the general importance of Fe minerals in P capture and subsidiary roles for Al, Ca and Si. A 3-week barley (Hordeum vulgare) seedling growth experiment was conducted using the pelletised and P-exposed biochars, in comparison with other biochars produced using feedstock which contained high amounts of PTEs. The biochars were also extracted using a range of different methods used to assess the bioavailability of PTEs and nutrients in soils, and the results compared to digests of barley leaves to identify whether any of these could reliably predict plant bioavailability in biochar. The above ground biomass and its total P concentration of barley grown in a 5% mixture of EPOCAD550 in sand was significantly higher than the control (p < 0.05 and p < 0.01, respectively). A significant positive correlation between mean leaf P mass and dry weight leaf yield (R2 = 0.865, p < 0.001) was found, indicating that dry weight yield could be used as an indicator for the P fertilising capability of biochar for barley seedlings. Element concentrations in unbuffered and buffered and (pH 7) 0.01 M CaCl2 biochar extractions were significantly positively correlated with plant leaf concentration for 6 of the 18 elements investigated, more than any of the other extractions. A longer barley growth experiment was conducted, using rhizoboxes, to test the bioavailability of P in the biochars compared to conventional fertiliser. The pelletised and Pexposed biochars were applied to a sandy loam soil with P constraints. Biochar application rates were based on 2% formic acid extractable P, calculated for summer barley using Index 0 soil. Analysis of total leaf length at harvest (12 weeks), dry weight yield, leaf P concentration and leaf P mass showed no significant differences between the biochar treatments, NPK fertilised and NK fertilised controls. This shows that biochar, when applied at low total application rates based on extractable P, is as effective as conventional fertiliser. Now that AD biochar materials have been shown to have useful phosphorus recycling properties in laboratory experiments, additional work is required to optimise their use in wastewater and agricultural systems. The next stage of research should determine their performance in flow-through filtration systems with simulated and real wastewater effluent, as well as their performance in field trials with different crops of interest to demonstrate their potential as viable alternative fertilisers

Constraints on Dark Matter from Colliders

We show that colliders can impose strong constraints on models of dark matter, in particular when the dark matter is light. We analyze models where the dark matter is a fermion or scalar interacting with quarks and/or gluons through an effective theory containing higher dimensional operators which represent heavier states that have been integrated out of the effective field theory. We determine bounds from existing Tevatron searches for monojets as well as expected LHC reaches for a discovery. We find that colliders can provide information which is complementary or in some cases even superior to experiments searching for direct detection of dark matter through its scattering with nuclei. In particular, both the Tevatron and the LHC can outperform spin dependent searches by an order of magnitude or better over much of parameter space, and if the dark matter couples mainly to gluons, the LHC can place bounds superior to any spin independent search.Comment: 23 pages, 16 figure