23,714 research outputs found
The association between hysterectomy and ovarian cancer risk: A population-based record-linkage study
Background: Recent studies have called into question the long-held belief that hysterectomy without oophorectomy protects against ovarian cancer. This population-based longitudinal record-linkage study aimed to explore this relationship, overall and by age at hysterectomy, time period, surgery type, and indication for hysterectomy.
Methods: We followed the female adult Western Australian population (837 942 women) across a 27-year period using linked electoral, hospital, births, deaths, and cancer records. Surgery dates were determined from hospital records, and ovarian cancer diagnoses (n¼1640) were ascertained from cancer registry records.We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between hysterectomy and ovarian cancer incidence.
Results: Hysterectomy without oophorectomy (n¼78 594) was not associated with risk of invasive ovarian cancer overall (HR ¼ 0.98, 95% CI ¼ 0.85 to 1.11) or with the most common serous subtype (HR ¼ 1.05, 95% CI ¼ 0.89 to 1.23). Estimates did not vary statistically significantly by age at procedure, time period, or surgical approach. However, among women with endometriosis (5.8%) or with fibroids (5.7%), hysterectomy was associated with substantially decreased ovarian cancer risk overall (HR ¼ 0.17, 95% CI ¼ 0.12 to 0.24, and HR ¼ 0.27, 95% CI ¼ 0.20 to 0.36, respectively) and across all subtypes.
Conclusions: Our results suggest that for most women, having a hysterectomy with ovarian conservation is not likely to substantially alter their risk of developing ovarian cancer. However, our results, if confirmed, suggest that ovarian cancer risk reduction could be considered as a possible benefit of hysterectomy when making decisions about surgical management of endometriosis or fibroids
Bumpy Power Spectra and dT/T
With the recent publication of the measurements of the radiation angular
power spectrum from the BOOMERanG Antarctic flight (de Bernardis et al. 2000),
it has become apparent that the currently favoured spatially-flat cold dark
matter model (matter density parameter , flatness being
restored by a cosmological constant , Hubble parameter
, baryon density parameter ) no longer provides
a good fit to the data. We describe a phenomenological approach to resurrecting
this paradigm. We consider a primordial power spectrum which incorporates a
bump, arbitrarily placed at , and characterized by a Gaussian in log
of standard deviation and amplitude ,
that is superimposed onto a scale-invariant power spectrum. We generate a range
of theoretical models that include a bump at scales consistent with cosmic
microwave background and large-scale structure observations, and perform a
simple test to compare our models with the DMR data and the
recently published BOOMERanG and MAXIMA data. Unlike models that include a high
baryon content, our models predict a low third acoustic peak. We find that low
observations (20 200) are a critical discriminant of the
bumps because the transfer function has a sharp cutoff on the high side
of the first acoustic peak...Comment: 5 pages, 5 figures, updated reference
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The effects of a chemosterilant (Mestranol) on population and behavior in the Richardson's ground squirrel (Spermophilus richardsonii) in Alberta
A chemosterilant, mestranol, was administered to three populations of Richardson's ground squirrel in southeastern Alberta. Mestranol was given to all squirrels in one plot, to only 50 percent in another plot, while a third plot remained as control. In all plots social behavior and population dynamics were followed over two seasons by live trapping and visual observations. Mestranol sterilized all females who received the drug shortly before or in early pregnancy; accordingly the birth rates were reduced. Levels of total aggression were also reduced but increased survival and immigration rates nullified the effects of the treatment during the first season. During the second season, low birth rates due to repeated treatment in one plot and to adult emigration and unknown causes in the other, were not compensated for by immigration. As a result of the repeated mestranol treatment and in one case also of adult emigration, the numbers of squirrels were reduced in the vicinity, thus limiting potential immigration in the treated plots. As a consequence, both treated populations crashed, demonstrating the effectiveness of mestranol
Structure and Magnetic Properties of a 1D Alternating Cu(II) Monomer―Paddlewheel Chain
One-dimensional metal–organic coordination polymers make up a class of compounds with potential towards the development of practical, new magnetic materials. Herein, a rare example of an ABBABB coupled linear chain comprised of alternating dicopper(II) tetraacetate units bridged to copper(II) acetate monomer units via axial η2:η1:µ2 coordinated acetate is reported. Examination of the structure, determined by small molecule X-ray crystallography, shows that each Cu(II) ion is in a dx2–y2 magnetic ground state. Magnetic susceptibility and magnetization data were collected and, consistent with the structural interpretation, demonstrate that the Cu(II) dimer (paddlewheel) exhibits classic antiferromagnetic exchange, while the S = 1/2 Cu(II) monomer is uncompensated in the ground state (low temperature regime.) Data were therefore fitted to a modified Bleaney-Bowers model, and results were consistent with the only other reported chain in this class for which magnetic data are available
Educational videos for practitioners attending Baby Friendly Hospital Initiative workshops supporting breastfeeding positioning, attachment and hand expression skills: Effects on knowledge and confidence
UNICEF Baby Friendly Initiative (BFHI) is the global standard for maternity and community services requiring all practitioners to be trained to support mothers in the essential skills of supporting positioning and attachment, and hand expression. These studies aim to rigorously assess knowledge in nurses, midwives, and doctors in these skills, tested before and after watching short videos demonstrating these skills. Practitioners were attending BFHI education, and the video study was additional. In Phase 1 clinicians in England were randomised to one of two videos (practitioner role play or clinical demonstration). The results showed improvements in knowledge and confidence, and a preference for clinical demonstration by mothers and infants. The clinical demonstration video was evaluated in China in Phase 2 where expert trainers viewed the video after completing the BHFI workshop, and in Phase 3 practitioners viewed the video before the BHFI workshop. Phase 2 with expert trainers only showed improvement in knowledge of hand expression but not positioning and attachment. In Phase 3 clinicians showed improved knowledge for both skills. In all Phases there were statistically significant improvements in confidence in practice in both skills.
Viewing short videos increased knowledge, particularly about teaching hand expression, and confidence in both skills
Assessing intonation skills in a tertiary music training programme
[Abstract]: Buttsworth, Fogarty, and Rorke (1993) reported the construction of a battery of tonal
tests designed to assess intonation abilities. A subset of the tests in the battery
predicted 36 per cent of final scores in an aural training subject in a tertiary music course. In
the current study, the original battery of fourteen tests was reduced to six tests and
administered three times throughout the academic year to a new sample (N = 87) of
tertiary music students. Three research questions were investigated. Firstly, it was
hypothesised that tests in the battery would discriminate among the different aural
classes at USQ, which were grouped according to ability level. The results from
discriminant function analyses provided strong support for this hypothesis. Secondly,
it was hypothesised that students should improve their performance on the pitch
battery across the three administrations. A repeated measures analysis of variance
failed to find evidence of overall improvement. Finally, it was hypothesised that there
would be significant differences on the intonation tests between musicians of different
instrumental families. Again, no overall differences were found. The results indicated
that intonation tests appear to tap an ability that (a) is not significantly modified by
training, (b) is more or less the same across different instrument families, and (c) is
related to success in music training programmes
Internet-based CBT for depression with and without telephone tracking in a national helpline: randomised controlled trial
BACKGROUND Telephone helplines are frequently and repeatedly used by individuals with chronic mental health problems and web interventions may be an effective tool for reducing depression in this population. AIM To evaluate the effectiveness of a 6 week, web-based cognitive behaviour therapy (CBT) intervention with and without proactive weekly telephone tracking in the reduction of depression in callers to a helpline service. METHOD 155 callers to a national helpline service with moderate to high psychological distress were recruited and randomised to receive either Internet CBT plus weekly telephone follow-up; Internet CBT only; weekly telephone follow-up only; or treatment as usual. RESULTS Depression was lower in participants in the web intervention conditions both with and without telephone tracking compared to the treatment as usual condition both at post intervention and at 6 month follow-up. Telephone tracking provided by a lay telephone counsellor did not confer any additional advantage in terms of symptom reduction or adherence. CONCLUSIONS A web-based CBT program is effective both with and without telephone tracking for reducing depression in callers to a national helpline. TRIAL REGISTRATION Controlled-Trials.comISRCTN93903959.Funding for the trial was provided by an Australian Research Council Linkage Project Grant (LP0667970) (http://www.arc.gov.au/). LF is supported by an
Australian Postgraduate Award Industry scholarship. KG is supported by a National Health and Medical Research Council Fellowship (No. 525413) and HC is
supported by a National Health and Medical Research Council Fellowship (No. 525411)
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