Contextualizing and Expanding Conversational Queries without Supervision

Most conversational passage retrieval systems try to resolve conversational dependencies by using an intermediate query resolution step. To do so, they synthesize conversational data or assume the availability of large-scale question rewriting datasets. To relax those conditions, we propose a zero-shot unified resolution–retrieval approach, that (i) contextualizes and (ii) expands query embeddings using the conversation history and without fine-tuning on conversational data. Contextualization biases the last user question embeddings towards the conversation. Query expansion is used in two ways: (i) abstractive expansion generates embeddings based on the current question and previous history, whereas (ii) extractive expansion tries to identify history term embeddings based on attention weights from the retriever. Our experiments demonstrate the effectiveness of both contextualization and unified expansion in improving conversational retrieval. Contextualization does so mostly by resolving anaphoras to the conversation and bringing their embeddings closer to the important resolution terms that were omitted. By adding embeddings to the query, expansion targets phenomena of ellipsis more explicitly, with our analysis verifying its effectiveness on identifying and adding important resolutions to the query. By combining contextualization and expansion, we find that our zero-shot unified resolution–retrieval methods are competitive and can even outperform supervised methods

High-intensity interval exercise training before abdominal aortic aneurysm repair ( HIT-AAA): protocol for a randomised controlled feasibility trial

Introduction In patients with large abdominal aortic aneurysm (AAA), open surgical or endovascular aneurysm repair procedures are often used to minimise the risk of aneurysm-related rupture and death; however, aneurysm repair itself carries a high risk. Low cardiopulmonary fitness is associated with an increased risk of early post-operative complications and death following elective AAA repair. Therefore, fitness should be enhanced before aneurysm repair. High-intensity interval exercise training (HIT) is a potent, time-efficient strategy for enhancing cardiopulmonary fitness. Here, we describe a feasibility study for a definitive trial of a pre-operative HIT intervention to improve post-operative outcomes in patients undergoing elective AAA repair. Methods and analysis A minimum of 50 patients awaiting elective repair of a 5.5–7.0 cm infrarenal AAA will be allocated by minimisation to HIT or usual care control in a 1:1 ratio. The patients allocated to HIT will complete three hospital-based exercise sessions per week, for 4 weeks. Each session will include 2 or 4 min of high-intensity stationary cycling followed by the same duration of easy cycling or passive recovery, repeated until a total of 16 min of high-intensity exercise is accumulated. Outcomes to be assessed before randomisation and 24–48 h before aneurysm repair include cardiopulmonary fitness, maximum AAA diameter and health-related quality of life. In the post-operative period, we will record destination (ward or critical care unit), organ-specific morbidity, mortality and the durations of critical care and hospital stay. Twelve weeks after the discharge, participants will be interviewed to reassess quality of life and determine post-discharge healthcare utilisation. The costs associated with the exercise intervention and healthcare utilisation will be calculated. Ethics and dissemination Ethics approval was secured through Sunderland Research Ethics Committee. The findings of the trial will be disseminated through peer-reviewed journals, and national and international presentations

Comparison of Spectra in Unsequenced Species

International audienceWe introduce a new algorithm for the mass spectromet- ric identication of proteins. Experimental spectra obtained by tandem MS/MS are directly compared to theoretical spectra generated from pro- teins of evolutionarily closely related organisms. This work is motivated by the need of a method that allows the identication of proteins of unsequenced species against a database containing proteins of related organisms. The idea is that matching spectra of unknown peptides to very similar MS/MS spectra generated from this database of annotated proteins can lead to annotate unknown proteins. This process is similar to ortholog annotation in protein sequence databases. The difficulty with such an approach is that two similar peptides, even with just one mod- ication (i.e. insertion, deletion or substitution of one or several amino acid(s)) between them, usually generate very dissimilar spectra. In this paper, we present a new dynamic programming based algorithm: Packet- SpectralAlignment. Our algorithm is tolerant to modications and fully exploits two important properties that are usually not considered: the notion of inner symmetry, a relation linking pairs of spectrum peaks, and the notion of packet inside each spectrum to keep related peaks together. Our algorithm, PacketSpectralAlignment is then compared to SpectralAlignment [1] on a dataset of simulated spectra. Our tests show that PacketSpectralAlignment behaves better, in terms of results and execution tim

Disparities in the management of paediatric splenic injury

Background: The non-operative management of splenic injury in children is recommended widely, and is possible in over 95 per cent of episodes. Practice appears to vary between centres. Methods: The Trauma Audit and Research Network (TARN) database was interrogated to determine the management of isolated paediatric splenic injuries in hospitals in England and Wales. Rates of non-operative management, duration of hospital stay, readmission and mortality were recorded. Management in paediatric surgical hospitals was compared with that in adult hospitals. Results: Between January 2000 and December 2015 there were 574 episodes. Children treated in a paediatric surgical hospital had a 95·7 per cent rate of non-operative management, compared with 75·5 per cent in an adult hospital (P < 0·001). Splenectomy was done in 2·3 per cent of children in hospitals with a paediatric surgeon and in 17·2 per cent of those treated in an adult hospital (P < 0·001). There was a significant difference in the rate of non-operative management in children of all ages. There was some improvement in non-operative management in adult hospitals in the later part of the study, but significant ongoing differences remained. Conclusion: The management of children with isolated splenic injury is different depending on where they are treated. The rate of non-operative management is lower in hospitals without a paediatric surgeon present

The languages of peace during the French religious wars

The desirability of peace was a common topos in sixteenth-century political rhetoric, and the duty of the king to uphold the peace for the benefit of his subjects was also a long-established tradition. However, the peculiar circumstances of the French religious wars, and the preferred royal policy of pacification, galvanized impassioned debate among both those who supported and those who opposed confessional coexistence. This article looks at the diverse ways in which peace was viewed during the religious wars through an exploration of language and context. It draws not only on the pronouncements of the crown and its officials, and of poets and jurists, but also on those of local communities and confessional groups. Opinion was not just divided along religious lines; political imperatives, philosophical positions and local conditions all came into play in the arguments deployed. The variegated languages of peace provide a social and cultural dimension for the contested nature of sixteenth-century French politics. However, they could not restore harmony to a war-torn and divided kingdom

Measuring Cosmic Defect Correlations in Liquid Crystals

From the theory of topological defect formation proposed for the early universe, the so called Kibble mechanism, it follows that the density correlation functions of defects and anti-defects in a given system should be completely determined in terms of a single length scale $\xi$, the relevant domain size. Thus, when lengths are expressed in units of $\xi$, these distributions should show universal behavior, depending only on the symmetry of the order parameter, and space dimensions. We have verified this prediction by analyzing the distributions of defects/anti-defects formed in the isotropic-nematic phase transition in a thin layer of nematic liquid crystals. Our experimental results confirm this prediction and are in reasonable agreement with the results of numerical simulations.Comment: 15 pages, 4 figures, minor changes, few new references adde

Single particle states in the heaviest known nuclei

Neutron single-particle states above the N=152 subshell have been studied by high-resolution (d,p) reaction on a {sup 250}Cf target. All of the orbitals between N=152 and N=164 subshells have been identified. A tentative assignment has been made for the 1/2-(750) Nilsson state. 10 refs

Biomaterials from beer manufacture waste for bone growth scaffolds

Agricultural wastes are a source of renewable raw materials (RRM), with structures that can be tailored for the use envisaged. Here, they have proved to be good replacement candidates for use as biomaterials for the growth of osteoblasts in bone replacement therapies. Their preparation is more cost effective than that of materials presently in use with the added bonus of converting a low-cost waste into a value-added product. Due to their origin these solids are ecomaterials. In this study, several techniques, including X-ray diffraction (XRD), chemical analysis, mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM), and bioassays, were used to compare the biocompatibility and cell growth of scaffolds produced from beer bagasse, a waste material from beer production, with a control sample used in bone and dental regenerative processes

Sustainable Materials and Biorefinery Chemicals from Agriwastes

This is an open access chapter distributed under the terms of the Creative Commons Attribution License.-- et al.Countries with economies based on agriculture generate vast amounts of low or null value wastes which may even represent an environmental hazard. In our group, agricultural industrial wastes have been converted into value added liquid substances and materials with several aims: decreasing pollution, giving added value to wastes and working in a sustainable manner in which the wastes of an industry can be used as the raw materials of the same or others, as the “cradle to cradle” philosophy states [1]. Sub-products from the agricultural food industry are being employed as renewable low cost raw materials in the preparation of Ecomaterials, designed for use in a number of industrial processes of great interest. Given their origin, these materials may compete with conventional ones since with this process a sustainable cycle is closed, in which the residues of one industry are used as raw materials in the same or other industries [2]. With regards to the composition of the residues produced from agriculture, the pH of soil is of great importance, since plants can only absorb the minerals that are dissolved in water and pH is mandatory for the physical, chemical and biological properties of soil and the main cause of many agronomic questions related to nutrient assimilation [3-5]. Variations of pH modify the solubility of most elements necessary for the development of crops and also influence the microbian activity of soil, which will affect the transformation of elements that are liberated to the soil and can be assimilated to form crops or not [3]. For example at pH lower than 6 or higher than 8 bacterian activities are lowered, the oxidation of nitrogen to nitrate is reduced and the amount of nitrogen available for plant food is decreased. However Al, Fe and manganese are more soluble at low pHs, reaching even toxic concentrations. Potassium and sulphur are easily adsorbed at pH higher than 6, calcium and magnesium between 7 and 8.5 and iron at pH lower than 6. For alkaline pH in soil, the availability of H2PO4-can be reduced through precipitation of phosphorous containing salts withcations such as calcium Ca2+ or magnesium Mg2+. However when soils have acid pH other compounds with HPO42-and iron (Fe2+), aluminium (Al3+) and manganese (Mn2+) can form, with increased solubility. The main factors that influence soil pH are the mineral composition and how it meteorizes, the decomposition of organic matter, how nutrients are partitioned among the solution and aggregates and of course the pluviometryof the zone and atmospheric contamination.Lower pHs are found in places with high pluviometry, with high organic matter decomposition, young soils developed on acid substrates, and places with high atmospheric contamination (acid rain). Depending on the species, crops can benefit from calcareous soils with high calcium carbonate content such as alfalfa, but other plants prefer soils with acid pH such as potatoes, coffee or tobacco. It is clear that different seasons will produce plants with a varying composition depending on the atmospheric conditions and therefore the materials derived from them need to be characterised and analysed to determine their possible uses.Given its multidisciplinary approach, this work is being carried out through the collaboration among national (Institute of Materials Science of Madrid (ICMM, CSIC), Institute of Catalysis (ICP, CSIC), Centre of Molecular Biology Severo Ochoa (UAM-CSIC), Polytechnic University of Madrid (UPM), University at distance (UNED), University Complutense of Madrid (UPM) and international (University of Sheffield and University of Ghent) research groups, in addition to various industries interested in the transformation of their residues and or sub-products into “value added materials”, with whom various research projects have been and are being sponsored by the MICINN and CDTI.Peer Reviewe