Language in Chemistry: The Effect of Some Aspects of Language on O Grade Chemistry Candidates

The thesis considers the function of language as a medium of communication in a very restricted area, namely multiple choice chemistry questions, and in the introduction some of the deeper issues are pointed out in order to insist that what is said later only scratches the surface of enormous problems. The literature indicating the connection between language and learning is reviewed and the comparison is made between the situation in primary schools, where there is recognition of the importance of language development and the situation in secondary schools where the subject specialist does not seem to be aware of the part language plays in learning. The factors e. g. social class, affecting language development and the problem of establishing a degree of difficulty of language are discussed in the introduction. The last part of the introduction is a review of language in science. Language is of fundamental importance to science: educational objectives assign knowledge of terminology to a position of primary importance; there is a large amount of specialised vocabulary and formalised writing is encouraged. The concern is for the lack of knowledge on language development of pupils, and the lack of structure in the presentation of language with the possible effect this may have on pupil performance. Experience with 'O' grade chemistry candidates in secondary schools seemed to indicate that language and words in particular may be a barrier to the understanding of chemistry. Three initial exercises are described 1) where pupils were asked to write the meaning of a word underlined in a sentence from an S.C.E. 'O' grade chemistry examination, (2) where pupils were asked to write a sentence, using similar words from similar sources, to show that they knew the meaning of the word, and (3) where pupils were presented with passages -from chemistry texts from which every seventh word had been deleted and they were asked to put in one word in each gap which they felt helped the passage to make sense. These initial exercises seemed to indicate that pupils had problems with words. The two major exorcises, which wore an attempt to show that in multiple choice chemistry questions language influences performance, are described. The organisation end design of the two exercises are basically the same, the second one being a more refined version than the first using larger samples. One thousand seven hundred and fifty six 'O' grade candidates in twenty four schools of varying catchment area were involved in the second major exercise. An outline of the organisation and the design of these exercises is: possible questions, which were written in two forms, were scrutinised by respected chemistry teachers to check that chemical content was the same; two tests were prepared ore in simplified language and one in original examination language; twenty eight multiple choice questions were used in each test - five were vocabulary questions, three were control chemistry questions identical in each test and twenty were in one of the two forms simplified or original: to try to achieve matched samples in the schools careful instructions were prepared which were in essence within each school the pupils were numbered and those who got an even number got one test while those with an odd number got the other test; and eventually the pupil answer cards were processed in appropriate batches by the computing department. The major exercises would seem to indicate that: (a) certain non-technical words cause pupils difficulties (b) certain pupils particularly those from a lower social class or with a low V.R.Q. have great difficulty with words (c) pupils' performance in multiple choice chemistry questions depends on V.R.Q., a measure of language development, and also on social class, a factor which influences language development. In multiple choice chemistry questions certain language factors have been identified as influencing performance namely (a) the presence of large numbers of unnecessary words (b) the words in key positions (c) the presence of negative expressions (d) expressions of qualification e.g. only (e) ambiguous expressions (f) the way in which clauses and sentences are put together

Computing the Cassels–Tate pairing on the 3-Selmer group of an elliptic curve

We extend the method of Cassels for computing the Cassels-Tate pairing on the 2-Selmer group of an elliptic curve, to the case of 3-Selmer groups. This requires significant modifications to both the local and global parts of the calculation. Our method is practical in sufficiently small examples, and can be used to improve the upper bound for the rank of an elliptic curve obtained by 3-descent

Dense Packings of Superdisks and the Role of Symmetry

We construct the densest known two-dimensional packings of superdisks in the plane whose shapes are defined by |x^(2p) + y^(2p)| <= 1, which contains both convex-shaped particles (p > 0.5, with the circular-disk case p = 1) and concave-shaped particles (0 < p < 0.5). The packings of the convex cases with p 1 generated by a recently developed event-driven molecular dynamics (MD) simulation algorithm [Donev, Torquato and Stillinger, J. Comput. Phys. 202 (2005) 737] suggest exact constructions of the densest known packings. We find that the packing density (covering fraction of the particles) increases dramatically as the particle shape moves away from the "circular-disk" point (p = 1). In particular, we find that the maximal packing densities of superdisks for certain p 6 = 1 are achieved by one of the two families of Bravais lattice packings, which provides additional numerical evidence for Minkowski's conjecture concerning the critical determinant of the region occupied by a superdisk. Moreover, our analysis on the generated packings reveals that the broken rotational symmetry of superdisks influences the packing characteristics in a non-trivial way. We also propose an analytical method to construct dense packings of concave superdisks based on our observations of the structural properties of packings of convex superdisks.Comment: 15 pages, 8 figure

The proportion of failures of the Hasse norm principle

For any number field we calculate the exact proportion of rational numbers which are everywhere locally a norm but not globally a norm from the number field

Renormalisation scheme for vector fields on T2 with a diophantine frequency

We construct a rigorous renormalisation scheme for analytic vector fields on the 2-torus of Poincare type. We show that iterating this procedure there is convergence to a limit set with a ``Gauss map'' dynamics on it, related to the continued fraction expansion of the slope of the frequencies. This is valid for diophantine frequency vectors.Comment: final versio

Attachment and Non-Suicidal Self-Injury among Young Adolescents: The Indirect Role of Behavioral Problems.

Non-suicidal self-injury (NSSI) often occurs before age 15, yet the majority of research on risk factors for this dangerous behavior has focused on samples of older participants. Insecure attachment has been previously identified as a risk factor for both NSSI and behavioral problems, and behavioral problems appear to be particularly associated with NSSI among young populations. Redressing the lack of young adolescent NSSI research, the present study uses longitudinal data from a sample of young adolescents to test a model in which insecure attachment acts as a prospective risk factor for NSSI via emotional and behavioral problems. Data on NSSI, child-mother attachment, and emotional and behavioral problems were collected from 559 (41.1% male) Flemish adolescents when they were 13 years old (M = 12.71, SD =0.32), and again 1 year later. Insecure attachment was measured using maternal items on the Experiences in Close Relationships-Revised Child scale. Psychological adjustment was assessed with the Strengths and Difficulties Questionnaire. We found that anxious and avoidant attachment were indirectly associated with NSSI through behavioral problems but not through emotional problems. Findings highlight the role of behavioral problems as a risk factor for NSSI in early adolescence, a rarely studied developmental period during which NSSI often first starts. Findings suggest that one possible pathway for the attachment-NSSI association among young adolescents is through behavioral problems. Therapies that improve child-parent attachment may reduce NSSI among young adolescents both directly, and indirectly by improving behavioral problems

Testing Hardy nonlocality proof with genuine energy-time entanglement

We show two experimental realizations of Hardy ladder test of quantum nonlocality using energy-time correlated photons, following the scheme proposed by A. Cabello \emph{et al.} [Phys. Rev. Lett. \textbf{102}, 040401 (2009)]. Unlike, previous energy-time Bell experiments, these tests require precise tailored nonmaximally entangled states. One of them is equivalent to the two-setting two-outcome Bell test requiring a minimum detection efficiency. The reported experiments are still affected by the locality and detection loopholes, but are free of the post-selection loophole of previous energy-time and time-bin Bell tests.Comment: 5 pages, revtex4, 6 figure

Maslov Indices and Monodromy

We prove that for a Hamiltonian system on a cotangent bundle that is Liouville-integrable and has monodromy the vector of Maslov indices is an eigenvector of the monodromy matrix with eigenvalue 1. As a corollary the resulting restrictions on the monodromy matrix are derived.Comment: 6 page