1,225 research outputs found
Hybrid XML Retrieval: Combining Information Retrieval and a Native XML Database
This paper investigates the impact of three approaches to XML retrieval:
using Zettair, a full-text information retrieval system; using eXist, a native
XML database; and using a hybrid system that takes full article answers from
Zettair and uses eXist to extract elements from those articles. For the
content-only topics, we undertake a preliminary analysis of the INEX 2003
relevance assessments in order to identify the types of highly relevant
document components. Further analysis identifies two complementary sub-cases of
relevance assessments ("General" and "Specific") and two categories of topics
("Broad" and "Narrow"). We develop a novel retrieval module that for a
content-only topic utilises the information from the resulting answer list of a
native XML database and dynamically determines the preferable units of
retrieval, which we call "Coherent Retrieval Elements". The results of our
experiments show that -- when each of the three systems is evaluated against
different retrieval scenarios (such as different cases of relevance
assessments, different topic categories and different choices of evaluation
metrics) -- the XML retrieval systems exhibit varying behaviour and the best
performance can be reached for different values of the retrieval parameters. In
the case of INEX 2003 relevance assessments for the content-only topics, our
newly developed hybrid XML retrieval system is substantially more effective
than either Zettair or eXist, and yields a robust and a very effective XML
retrieval.Comment: Postprint version. The editor version can be accessed through the DO
The kinetics of elementary reactions
The fundamental aim of the work contained in this thesis
is the better understanding of the factors that govern the
rates of chemical reactions. Most of the work is concerned
with the investigation of reactions in the gas phase, because
homogeneous gas reactions may be expected to yield most
readily to theoretical treatment. True gas reactions are free
from such complicating factors as solvatiot, adsorption and,
except in special cases, diffusion. There are however some
solution reactions which might be simple; they are the reactions
for which the transfer of a proton is the rate- determining
step. Some of the work in this thesis is concerned with
reactions of this type. It will be seen from the published
papers that the most complex experimental techniques are
often required to investigate the reactions of greatest
formal simplicity. The rate constants of these simple reactions
can usually only be measured when the experimental systems
are carefully designed for this specific purpose.Book. •
Gas Kinetics: An Introduction to the Kinetics of
Homogeneous Gas Reactions. • •
Published Papers. •
1. The Reactions of Methyl Radicals. •
2. Entropy Changes in Free Radical Reactions. •
3. Studies in Energy Transfer II. The Isomerization
of Cyclopropane -a quasi- Unimolecular Reaction.
with H.O.Pritchard and R.G.Sowden. •
4. Studies in Energy Transfer III. The Effect of
Added Gases on the Decomposition of Cyclobutane.
with H.O.Pritchard and R.G.Sowden. •
5., The Thermal Decomposition of Azomethane.
with H.O.Pritchard and M.Page. •
6. The Thermal Decomposition of t- Butylamine.
with H.O.Pritchard and R.G.Sowden. •
7. The Reactions of Methyl Radicals with Acetone,
Diethyl Ketone and Di -t -butyl Peroxide.
with G.O.Pritchard and H.O.Pritchard. •
8. The Exchange of Iodine Atoms between Iodine and
Methyl Iodide in the Temperature Range 150 -3751).
with D.Clark and H.O.Pritchard. •
9. The Study of Chlorine Atom Reactions in the Gas
Phase.
with H.O.Pritchard and J.B.Pyke. •
10. The Reactions of Trifluoromethyl Radicals.
with G.O.Pritchard, H.O.Pritchard and H.I.Schiff. •
11. The Thermal Decomposition of Cyclopentyl Bromide.
with S.J.W.Price and R.Shaw. •
12. The Reactions of Chlorine Atoms - A Test of the
Transition State Theory.
with J.H.Knox. •
13. The Crystal Structure of Nitramide, NH2NO2.
with C .A .Beevers. •
14. Recent Developments of Gas Kinetics. • •
General. •
15. The Teaching of Chemical Kinetics.
Shorter Contributions. •
16. A Method for the Study of Chlorine Atom Reaction.
The Reaction Cl - CH4 -- CH3 _ HC1.
with H.O.Pritchard and J.B.Pyke. •
17. The Photolysis of Acetaldehide.
with G.O.Pritchard and H.O.Pritchard. •
18. The C -C Bond Dissociation Enegies in Cyclanes.
with H.O.Pritchard. •
19. The C -C Bond Dissociation Energy in Cyclobutane.
with H.O.Pritchard. •
20. The Photolysis of Hexafluoroazomethane and the
Reactions of CF Radicals with Methane and nButane.
with G.O.Pritchard,and H.O.Pritchard. •
21. The C -H Bond Dissociation Energy in Fluorofom.
with G.O.Pritcha.rd, H.O.Pritchard and H.I.Schiff. •
22. The Reactions of Methylene.
with J.H.Knox. •
23. The Isomerization of Cyclopropane at very low
Pressures.
with H.O.Pritchard and R.G.Sowden. •
24. The Combination of Nitrogen Atoms.
with G.Boocock and H.O.Pritchard. • •
Papers in the course of publication. •
25. Carbon -Metal Bonds I. The Pyrolyses of Dimethyl
Mercury and Dimethyl Cadmium.
with S.J.'rA.Price. •
26. Carbon Metal Bonds 2. The Pyrolysis of Dimethyl
Zinc.
with S.J.W.Price. •
27. The Decomposition of Nitramide in Anisole Catalysed by Anilines.
with G.C.Fettes, J.A.Kerr, A.McClure, J.S.älater
and C.Steel. •
28. The Photoinitiated Decomposition of Acetaldehyde
Catalysed by Thiols.
with R.N.Birrell, R.F.Smith and H.Wilkie. •
29. The Pyrolysis of t -Butyl Forrñate.
with R.Gordon and S. J. W. Price. •
30. The Study of Free Radical Reaction by Competitive
methods.
with J.H.Knox. •
31. The Reactions of Methylene with Alkanes,
with J.H.Knox. •
32. The Reactions of Methyl Radicals with Thiols.
with J.A.Kerr
Using Proximity and Tag Weights for Focused Retrieval in Structured Documents
International audienceFocused information retrieval is concerned with the retrieval of small units of information. In this context, the structure of the documents as well as the proximity among query terms have been found useful for improving retrieval effectiveness. In this article, we propose an approach combining the proximity of the terms and the tags which mark these terms. Our approach is based on a Fetch and Browse method where the fetch step is performed with BM25 and the browse step with a structure enhanced proximity model. In this way, the ranking of a document depends not only upon the existence of the query terms within the document but also upon the tags which mark these terms. Thus, the document tends to be highly relevant when query terms are close together and are emphasized by tags. The evaluation of this model on a large XML structured collection provided by the INEX 2010 XML IR evaluation campaign shows that the use of term proximity and structure improves the retrieval effectiveness of BM25 in the context of focused information retrieval
PTEN Regulation of Local and Long-Range Connections in Mouse Auditory Cortex
Autism spectrum disorders (ASDs) are highly heritable developmental disorders caused by a heterogeneous collection of genetic lesions. Here we use a mouse model to study the effect on cortical connectivity of disrupting the ASD candidate gene PTEN (phosphatase and tensin homolog deleted on chromosome 10). Through Cre-mediated recombination, we conditionally knocked out PTEN expression in a subset of auditory cortical neurons. Analysis of long-range connectivity using channelrhodopsin-2 revealed that the strength of synaptic inputs from both the contralateral auditory cortex and from the thalamus onto PTEN-cko neurons was enhanced compared with nearby neurons with normal PTEN expression. Laser-scanning photostimulation showed that local inputs onto PTEN-cko neurons in the auditory cortex were similarly enhanced. The hyperconnectivity caused by PTEN-cko could be blocked by rapamycin, a specific inhibitor of the PTEN downstream molecule mammalian target of rapamycin complex 1. Together, our results suggest that local and long-range hyperconnectivity may constitute a physiological basis for the effects of mutations in PTEN and possibly other ASD candidate genes
Focal dermal hypoplasia (Goltz-Gorlin) syndrome with taurodontism
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74895/1/j.1754-4505.1996.tb01539.x.pd
Nasolabial Fold Dynamics: Implications for Facial Paralysis and Facial Reanimation Surgery
ObjectivesIn patients with facial paralysis, facial reanimation surgery may be needed to normalize facial soft tissue function/movements. Critical for this normalization is the dynamics of the nasolabial folds (NLFs). The objective of this prospective, observational study was to determine the 3D morphologic dynamics of the NLFs in patients with unilateral facial palsy and normal subjects.Settings and Sample Population3D facial soft tissue movement data collected from adults with unilateral, facial paralysis (Bell's Palsy, n=36); and (2) an age‐ and sex‐frequency matched control group (n=68).Materials and MethodsMovement data were collected during repeated animations from participants using a video‐based motion capture system. Movement in terms of displacement and asymmetry of the NLFs, nasal, and circumoral regions were analyzed in the lateral, vertical and depth planes; as well as movement of the commissure and NLFs relative to the lower lip midline. Two sample t tests were used to test for significant group differences.ResultsPatients NLFs had less mean displacement, greater mean asymmetry, and uncoordinated movements compared with the controls. For both groups during smiling, the NLF and commissure landmarks had approximately similar magnitudes of displacement (control range = 11‐14mm; patient range = 7‐10mm).ConclusionNLF dynamics during smiling were as significant as oral commissure excursion. Thus, an immobile NLF is an unnatural feature of facial animations. Surgical treatments that address impaired NFL movements must be considered to create a more natural surgical outcome especially during smiling.<br/
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