Using Semantic Ambiguity Instruction to Improve Third Graders\u27 Metalinguistic Awareness and Reading Comprehension: An Experimental Study

An experiment examined whether metalinguistic awareness involving the detection of semantic ambiguity can be taught and whether this instruction improves students\u27 reading comprehension. Lower socioeconomic status third graders (M age = 8 years, 7 months) from a variety of cultural backgrounds (N = 46) were randomly assigned to treatment and control groups. Those receiving metalinguistic ambiguity instruction learned to analyze multiple meanings of words and sentences in isolation, in riddles, and in text taken from the Amelia Bedelia series (Parish, 1979, 988). The control group received a book-reading and discussion treatment to provide special attention and to rule out Hawthorne effects. Results showed that metalinguistic ambiguity instruction was effective in teaching students to identify multiple meanings of homonyms and ambiguous sentences and to detect inconsistencies in text. Moreover, this training enhanced students\u27 reading com prehension on a paragraph-completion task but not on a multiple-choice passage-recall task, possibly because the two tests differ in the array of linguistic or cognitive correlates influencing performance. Comprehension monitoring was not found to mediate the relationship between ambiguity instruction and reading comprehension. Results carry implications for the use of language-based methods to improve reading comprehension in the classroom

A note on the evaluation of a beta-casein variant in bovine breeds by allele-specific PCR and relevance to β-casomorphin

peer-reviewedThis work was supported by Enterprise Ireland and by a Teagasc Walsh fellowship to A.F. Keating.Two genetic variants of the bovine β-casein gene (A1 and B) encode a histidine residue at codon 67, resulting in potential liberation of a bioactive peptide, β-casomorphin, upon digestion. An allele-specific PCR (AS-PCR) was evaluated to distinguish between the β-casomorphin-releasing variants (A1 and B) and the non-releasing variants. AS-PCR successfully distinguished β-casein variants in 41 of 42 animals as confirmed by sequence analysis. Overall, while the incidence of the homozygous A1 and B animals (i.e., homozygous for the histidine residue; 21.4%) was lower than that for animals without the histidine residue (30.9% respectively), 69% of animals carried at least one allele for the histidine residue at codon 67.Teagasc Walsh Fellowship ProgrammeEnterprise Irelan

Studies in the acridine series

In the Annual Reports on the Progress of Chemistry for 1918 under the heading "chromoisomerism" the following passage may be found: but it seems tine to protest against one halfpennyworth of practice to this intolerable deal of theory, and to demand something more than assertion in proof of the constitutional formulae which are drawn up so lavishly." It is fairly clear that the reviewer is referring principally to Hantzsch who originated the term "chromoisomeric" to describe compounds which exist in two or more solid modifications with distinctly different colours. Hantzsch (1) supposed that all such cases are to be explained in terms of isomerism and he proposed many structures.Hantzsch, however, was right in looking for an explanation and his reviewers were wrong where they dismissed the phenomena as being "merely polymorphism" (2). Polymorphism perhaps; but where, as in some cases, the colour change is pronounced - say from green to red - this is hardly a sufficient explanation.In the sequel the purely descriptive term polychromism will be used,in place of Hantzsch's "chromoisomerism'' to avoid the implication that isomerism is necessarily involved.We know that electronic absorption is not exclusively a function of molecular structure; it may be affected by the polar environment of the molecule and also by more specific intermolecular forces such as hydrogen bonding or charge transfer interaction. A crystal lattice may be regarded as a structure of intermolecular interactions; to change the lattice is to change these interactions and, in so far as some of these may influence light absorption, to change the colour.But the problem remains. If there is no difference in the structure or conformation of the molecules in Lifferent polychromic states then there must be a difference in one or other of those forms of intermolecular interaction which can have a significant effect on colour and it should be possible to specify which of these is involved.Most polychromic organic compounds for which no evident explanation in terms of isomerism exists, are either salts or aromatic nitro -compounds (usually polynitro-compounds and usually phenols or amines). The origin of polychromism in these cases has not been fully established, but it may well be that comparatively recent work on charge transfer phenomena will provide at least a partial answer. Charge transfer might be expected to occur in the solid state with both of these classes of compounds.It is well known that aromatic polynitro-compounds can form coloured molecular compounds with aromatic hydrocarbons, amines,phenols etc. The formation of such compounds has been attributed to charge transfer interaction between the components one of which must be a Lewis acid (e.g. a nitro - compound) and the other á Lewis base (e.g. an aromatic hydrocarbon or amine) (3 a - e).This type of interaction gives rise to a new absorption band, which has been called the charge transfer spectrum, in the visible or near ultra -violet regions. It appears to be due to the occurrence of electronic transitions between rather than within molecules. Charge transfer spectra are always broad and without fine structure. This is probably due (3a) to the weakness of the charge transfer bonding (2 - 4 K.cals. /mole (4)) allowing thermal vibration to provide a considerable range of displacements and orientations between the interacting groups. If the energy required for these intermolecular transitions does indeed depend upon the orientation of the interacting groups in the crystal - and this seems probable - then the colour of the solid will be a function of crystal structure. Thus where a compound, which shows charge transfer interaction in the solid, is polymorphic it will in general be polychromie.This charge transfer hypothesis for polychromism must be regarded as a more modern version of a theory put forward by Pfeiffer (8) as early as 1915 in terms of residual valency. He proposed that the orange and yellow forms of nitromethoxystilbenes result from the orientations A and B respectively in the solids.No work appears to have been done in order to decide whether charge transfer can occur in organic salts: its occurrence in inorganic salts appears to be very common. It is too early therefore to judge whether an extension of the charge transfer idea to cover the numerous cases of polychromism in organic salts is justifiable. A purely electrostatic theory has been proposed by Lucas and Kemp (9) to explain the polychromism of organic and inorganic salts. Their general conclusion is that the electronic absorption of an ion in a crystal lattice will depend on its electrostatic environment, created by the surrounding ions of opposite charge, and that this will depend on the crystal structure.Although at present it is not possible to decide which, if any, of these theories is true, one thing is clear: where a compound exists in more than one differently coloured solid form it is not possible to conclude directly from this that different molecular structures must be assigned to these forms. On the other hand a knowledge of the general classes of compounds which show polychromism and an appreciation of the factors which may influence light absorption in a crystal will help in deciding, in specific cases, whether it is worth looking for an explanation in terms of isomerism. For example if the compound in question is a salt or a polynitrocompound, or indeed if it is a betaine or contains both Lewis acid and Lewis base functions, any "isomeric" theory will be somewhat unconvincing. But the converse also is true.According to Kehrmann and Matusinsky (10) 2- hydroxy5- phenylacridine crystallises from hot benzene as fine yellow needles with a melting point of 264 °C. On crystallising slowly from cold benzene red prisms are obtained which may be converted to the yellow form by heating at 135 °C. The red modification is formed from the yellow slowly on standing and rapidly by crushing and powdering. From these observations it was concluded that the yellow is the form stable at higher temperatures and the red the lower temperature stable form.In view of the difference of more than 100 °C between the melting points of the two forms and in view of their strong difference in colour, Kehrmann suggested that this was a case of tautomerism between the structures.Neither argument is very convincing and the great ease with which the red modification can be formed from the yellow would seem to weigh heavily in favour of an explanation in terms of polymorphism. But if this example is considered in the context of polychromism in general and in the light of work carried out more recently by John (11) and by Albert and Short (12) on the tautomerism of analogous compounds, Kehrmann's theory becomes distinctly more probable.In the first place 2- hydroxy- 5- phenylacridine does not fall into any of the general classes of polychromic compounds: 8. this appears to be the only published example of a polychromic free acridine (although polychromism in acridine salts is very common). On the other hand John has studied a group of 2- hydroxy -phenazine derivatives.This compound exists in a yellow and a deep violet modification,these colours corresponding to the colours of the 0- Methyl and N- Methyl derivatives respectively. In solution 1:3:4 trimethyl- 2- hyäroxyphenazine is present as an equilibrium mixture of the structures(IIIa) and (IIIb). John concluded that the yellow and violet modifications were to be identified with (IIIa) and (IIIb) respectively. In this case however interconversion between the solids can only be brought about by recrystallising from solution or by heating to 135 °C at which temperature sublimation can be seen to occur.Albert and Short (12) have shown that 2- hydroxyacridine also is tautomeric (although not polychromic) existing in solution as an equilibrium mixture of lactim and lactam structures analogous to (I) and (II). Here the lactim structure is yellow and the lactam structure red.Kehrmann and P+iatusinsky's theory might now seem to be so reasonable as to be hardly worth questioning. But there remains one difficulty: the yellow crystals of 2- hydroxy- 5- phenylacridine can be converted to the red modification simply by rub-uing. If this is a tautomeric change it occurs with remarkable facility.It was therefore decided to investigate more thoroughly the colour changes of 2- hydroxy -5- phenylacridine

Diet behaviour among young people in transition to adulthood (18–25 year olds) : a mixed method study

Peer reviewedPublisher PD

Understanding patient choices for attending sexually transmitted infection testing services: a qualitative study

Objectives: To establish which aspects of sexually transmitted infection (STI) testing services are important to STI testing service users. Methods: 10 focus groups consisting of previous or existing users of STI testing services were conducted in community settings in the south east of England. Groups were quota sampled based on age, gender and sexual orientation. Data were analysed using Framework Analysis. Results: 65 respondents (58% men) participated. Perceived expertise of staff was the key reason for attendance at genitourinary medicine services rather than general practice. Although some respondents voiced a willingness to test for STIs within general practice, the apparent limited range of tests available in general practice and the perceived lack of expertise around sexual health appeared to discourage attendance at general practice. The decision of where to test for STIs was also influenced by past experience of testing, existing relationships with general practice, method of receiving test results and whether the patient had other medical conditions such as HIV. Conclusions: No one type of STI testing service is suitable for all patients. This is recognised by policymakers, and it now requires commissioners and providers to make services outside of genitourinary medicine clinics more acceptable and attractive to patients, in particular to address the perceived lack of expertise and limited range of STIs tests available at alternative testing sites

A Systematic Review of Economic Evaluations of Chemoprophylaxis for Tuberculosis

Since treatment of active disease remains the priority for tuberculosis control, donors and governments need to be convinced that investing resources in chemoprophylaxis provides health benefits and is good value for money. The limited evidence of cost effectiveness has often been presented in a fragmentary and inconsistent fashion. Objective. This review is aimed at critically reviewing the evidence of cost effectiveness of chemoprophylaxis against tuberculosis, identifying the important knowledge gaps and the current issues which confront policy makers. Methods. A systematic search on economic evaluations for chemoprophylaxis against tuberculosis was carried out, and the selected studies were checked for quality assessment against a standard checklist. Results. The review provides evidence of the cost effectiveness of chemoprophylaxis for all age groups which suggests that current policy should be amended to include a focus on older adults. Seven of the eight selected studies were undertaken wholly in high income countries but there are considerable doubts about the transferability of the findings of the selected studies to low and middle income countries which have the greatest incidence of latent tuberculosis infection. Conclusion. There is a pressing need to expand the evidence base to low and middle income countries where the vast majority of sufferers from tuberculosis live

Assessing user preferences for sexually transmitted infection testing services: a discrete choice experiment

Objective: To assess user preferences for different aspects of sexually transmitted infection (STI) testing services. Design: A discrete choice experiment. Setting: 14 centres offering tests for STIs in East Sussex, England. Participants: People testing for STIs. Main outcome measure: (Adjusted) ORs in relation to preferred service characteristics. Results: 3358 questionnaires were returned; mean age 26 (SD 9.4) years. 70% (2366) were recruited from genitourinary medicine (GUM) clinics. The analysis suggested that the most important characteristics to users were whether 'staff had specialist STI knowledge' compared with 'staff without it' (OR 2.55; 95% CI 2.47 to 2.63) and whether 'tests for all STIs' were offered rather than 'some' (OR 2.19; 95% CI 2.12 to 2.25). They remained the most important two service characteristics despite stratifying the analysis by variables such as age and sex. Staff levels of expertise were viewed as particularly important by people attending CASH centres, women and non-men who have sex with men. A 'text or call to a mobile phone' and 'dropping in and waiting' were generally the preferred methods of results reporting and appointment system, respectively. Conclusions: This study suggests that people testing for STIs place particular importance on testing for all infections rather than some and staff with specialist STI knowledge. Thus, targets based purely on waiting up to 48 h for an appointment are misguided from a user perspectiv

Long-term weight loss effects on all cause mortality in overweight/obese populations

This systematic review assesses the long-term effectiveness of weight loss on all cause mortality in overweight/obese people. Medline, Embase and Cinahl were searched (1966–2005). Cohort studies and trials on participants with Body Mass Index ¡Ý25 kg/m2, with weight change and mortality with ¡Ý 2 years follow-up were included finally identifying 11 papers based on 8 studies. There may be gender differences in the benefits for all cause mortality. The impact of weight loss in men on mortality was not clear with some studies indicating weight loss to be detrimental, while a recent cohort study showed benefits, if it were a personal decision. Other studies with no gender separation had similarly mixed results. However, one study indicated that overweight/obese women with obesity related illness, who lost weight intentionally within one year, had significantly reduced mortality rates of 19% -25%. In contrast, studies of overweight/obese diabetics irrespective of gender, showed significant benefit of intentional weight loss on mortality in a metaanalysis, HR=0.75(0.67- 0.83). There is some evidence that intentional weight loss has long-term benefits on all cause mortality for women and more so for diabetics. Long-term effects especially for men are not clear and need further investigation.National Health Service (NHS) R&D Health Technology Assessment Board

Self-replication and evolution of DNA crystals

Is it possible to create a simple physical system that is capable of replicating itself? Can such a system evolve interesting behaviors, thus allowing it to adapt to a wide range of environments? This paper presents a design for such a replicator constructed exclusively from synthetic DNA. The basis for the replicator is crystal growth: information is stored in the spatial arrangement of monomers and copied from layer to layer by templating. Replication is achieved by fragmentation of crystals, which produces new crystals that carry the same information. Crystal replication avoids intrinsic problems associated with template-directed mechanisms for replication of one-dimensional polymers. A key innovation of our work is that by using programmable DNA tiles as the crystal monomers, we can design crystal growth processes that apply interesting selective pressures to the evolving sequences. While evolution requires that copying occur with high accuracy, we show how to adapt error-correction techniques from algorithmic self-assembly to lower the replication error rate as much as is required

Large scale motions of Neptune's bow shock: Evidence for control of the shock position by the rotation phase of Neptune's magnetic field

The Voyager 2 spacecraft observed high levels of Langmuir waves before the inbound crossing of Neptune's bow shock, thereby signifying magnetic connection of the bow shock. The Langmuir waves occurred in multiple bursts throughout two distinct periods separated by an 85 minute absence of wave activity. The times of onsets, peaks, and disappearances of the waves were used together with the magnetic field directions and spacecraft position, to perform a 'remote-sensing' analysis of the shape and location of Neptune's bow shock prior to the inbound bow shock crossing. The bow shock is assumed to have a parabolidal shape with a nose location and flaring parameter determined independently for each wave event. The remote-sensing analysis give a shock position consistent with the time of the inbound shock crossing. The flaring parameter of the shock remains approximately constant throughout each period of wave activity but differs by a factor of 10 between the two periods. The absence of waves between two periods of wave activity coincides with a large rotation of the magnetic field and a large increase in the solar wind ram pressure' both these effects lead to magnetic disconnection of the spacecraft from shock. The planetwards motion of the shock's nose from 38.5 R(sub N) to 34.5 R(sub N) during the second time period occurred while the solar wind ram pressure remained constant to within 15 percent. This second period of planetwards motion of the shock is therefore strong evidence for Neptune's bow shock moving in response to the rotation of Neptune's oblique, tilted magnetic dipole. Normalizing the ram pressure, the remotely-sensed shock moves sunwards during the first wave period and planetwards in the second wave period. The maximum standoff distance occurs while the dipole axis is close to being perpendicular to the Sun-Neptune direction. The remote-sensing analysis provides strong evidence that the location of Neptune's bow shock is controlled by Neptune's rotation phase