108 research outputs found
Fixing numbers for matroids
Motivated by work in graph theory, we define the fixing number for a matroid.
We give upper and lower bounds for fixing numbers for a general matroid in
terms of the size and maximum orbit size (under the action of the matroid
automorphism group). We prove the fixing numbers for the cycle matroid and
bicircular matroid associated with 3-connected graphs are identical. Many of
these results have interpretations through permutation groups, and we make this
connection explicit.Comment: This is a major revision of a previous versio
A Doctrine Without Exception: Critiquing an Immigration Exception to the Anticommandeering Rule
Great expectations: teenage pregnancy and intergenerational transmission
PhD ThesisThirteen women composed the life stories that form the basis of this thesis. The
women, each with experience of pregnancy before the age of twenty, are connected
as mothers and daughters across generations in six white, working class families in
a setting in North East England. Their accounts are a medium for exploring
intergenerational transmission of values, beliefs and practices relating to young
women’s sexual relationships and pregnancies. Current UK policy defines teenage pregnancy as a social problem and a ten-year plan aims to halve the rate of undereighteen conceptions in England by 2010. Despite a substantial body of teenage
pregnancy literature, relatively little attention has been given to women’s
representations of how they learnt about sex and relationships, began sexual
relationships with men, became pregnant and decided what to do next. The
research addresses this gap in one UK area.
The women’s accounts, produced in biographical narrative interviews, show how
professional anecdotes about a cycle of teenage pregnancy ignore historically
changing definition of some pregnancies (and by implication, some sexual
relationships) as ‘out of order’. This is reflected in a vocabulary shift from
‘illegitimacy’ to ‘single parenthood’ to ‘teenage pregnancy’, with changing stigma and consequences for individual women. Interview data suggest no intergenerational
transmission of a message promoting teenage pregnancy, rather the degree to
which pregnancy is contingent on circumstance and linked with reproduction of
gender and social class positions. Women expressed mixed feelings about
becoming a mother, grandmother and great-grandmother “too young”, as well as
investment in these social identities.
Transmission of information about sexuality and sex has improved across the
generations. However, younger women’s accounts indicate that they are still not
equipped to discuss and negotiate pleasurable and safer sex within heterosexual
relationships. The women were generally positive about relationships with men, and
a significant minority referred to the impact of male violence. The women’s accounts
illustrate intergenerational exchange of practical (eg childcare) and emotional
support, as well as transmission of aspiration for a “good job”, although no transfer of financial wealth.Economic and Social Research Counci
Duration of antibiotic treatment for common infections in English primary care: cross sectional analysis and comparison with guidelines
Objectives:
To evaluate antibiotic therapy durations for common infections in English primary care and to compare this with guidelines.
Design:
Cross-sectional study.
Setting:
General practices contributing to The Health Improvement Network database, 2013-2015.
Participants:
931,015 consultations that resulted in an antibiotic prescription for one of the following indications: acute sinusitis, acute sore throat, acute cough and bronchitis, pneumonia, acute exacerbation of chronic obstructive pulmonary disease (COPD), acute otitis media, acute cystitis, prostatitis, pyelonephritis, cellulitis, impetigo, scarlet fever and gastroenteritis.
Main outcome measures:
The main outcomes were the percentage of antibiotic prescriptions with a duration exceeding the guideline recommendation and the total number of days beyond the recommended duration for each indication.
Results:
The most common reasons for the prescriptions were patients consulting with acute bronchitis and cough (386,972), acute sore throat (239,231), acute otitis media (83,054), and acute sinusitis (76,683). Antibiotic treatments for upper respiratory indications and acute bronchitis accounted for more than two thirds of the total prescriptions considered, and ≥80% of these treatment courses exceeded guideline recommendations. Notable exceptions were acute sinusitis, where only 9.6% (95% CI 9.4 to 9.9%) of prescriptions exceeded 7 days and acute sore throat where only 2.1% (95% CI 2.0 to 2.1) exceed 10 days (recent guidance recommends 5 days). More than half of antibiotic prescriptions were longer than guidelines recommend for acute cystitis among females (54.6%, 95% CI 54.1 to 55.0%). The percentage of antibiotic prescriptions exceeding the recommended duration was lower for most non-respiratory infections. For the 931,015 included consultations resulting in antibiotic prescriptions, approximately 1.3 million days were beyond the durations recommended by the guidelines.
Conclusion:
For most common infections treated in primary care, a substantial proportion of antibiotic prescriptions have durations exceeding those recommended in guidelines. Substantial reductions in antibiotic exposure can be accomplished by aligning antibiotic prescription durations with guidelines
In Vivo Measurements of Tumor Metabolism and Growth after Administration of Enzastaurin Using Small Animal FDG Positron Emission Tomography
Background. The use of 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) may help to establish the antitumor activity of enzastaurin, a novel protein kinase C-beta II (PKC-βII) inhibitor, in mouse xenografts. Methods. The hematologic cell line RAJI and the solid tumor cell line U87MG were each implanted in NOD/SCID mice. Standard tumor growth measurements and [18F]FDG PET imaging were performed weekly for up to three weeks after tumor implantation and growth. Results. Concomitant with caliper measurements, [18F]FDG PET imaging was performed to monitor glucose metabolism. Heterogeneity of glucose uptake in various areas of the tumors was observed after vehicle or enzastaurin treatment. This heterogeneity may limit the use of [18F]FDG PET imaging to measure enzastaurin-associated changes in xenograft tumors. Conclusion. [18F]FDG PET imaging technique does not correlate with standard caliper assessments in xenografts to assess the antitumor activity of enzastaurin. Future studies are needed to determine the use of [18F]FDG PET imaging in preclinical models
Dietary fat intakes in Irish adults in 2011: how much has changed in 10 years?
Imbalances in dietary fat intakes are linked to several chronic diseases. This study describes dietary intakes and food sources of fat and fatty acids in 1051 Irish adults (aged 18–90 years), using data from the 2011 national food consumption survey, the National Adult Nutrition Survey. It also compares current intakes for 18–64-year-olds with those reported in the last such survey in 2001, the North/South Ireland Food Consumption Survey. Dietary fat intakes were estimated using data from 4-d semi-weighed (2011) and 7-d estimated (2001) food diaries. In 2011, intakes for 18–64-year-olds were as follows: total fat, 34·1 (sd 6·1) % total energy (%TE); SFA, 13·3 (sd 3·3) %TE; MUFA, 12·5 (sd 2·6) %TE; PUFA, 6·1 (sd 2·2) %TE; and trans-fat, 0·511 (sd 0·282) %TE. Apart from MUFA, intakes decreased (P65 years had the highest intakes of SFA; however, intakes were typically higher than UK-recommended values for all groups. In contrast, intakes of long-chain n-3 fatty acids were lowest in younger age groups. Intakes of trans-fat were well within UK-recommended levels. Although there have been some improvements in the profile of intakes since 2001, imbalances persist in the quantity and quality of dietary fat consumed by Irish adults, most notably for total and SFA and for younger age groups for long-chain n-3 fatty acids
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