Dynamic susceptibility of concentric permalloy rings with opposite chirality vortices.

The high frequency dynamic behaviour of concentric permalloy nanorings with vortex domain structures with a thickness of 20 nm, a width in the range of 100 nm-250 nm, and a separation in the range of 10 nm-600 nm is investigated by micromagnetic simulations. The aim is to explore the ferromagnetic resonance of the concentric ring structure as a function of geometric parameters of the system. The dynamic susceptibility spectrum and spatial localization of the ferromagnetic resonance mode are investigated for varying ring widths and separations. The frequency of oscillation is significantly impacted by the presence of the magnetostatic interaction between each ring and can be modulated by a variation in the ring width and separation. The spatial localization of the uniform mode is found to vary as a function of ring separation, which corresponds to a large variation in amplitude of the real and imaginary components of the dynamic susceptibility.

Time-resolved imaging of magnetic vortex dynamics using holography with extended reference autocorrelation by linear differential operator.

The magnetisation dynamics of the vortex core and Landau pattern of magnetic thin-film elements has been studied using holography with extended reference autocorrelation by linear differential operator (HERALDO). Here we present the first time-resolved x-ray measurements using this technique and investigate the structure and dynamics of the domain walls after excitation with nanosecond pulsed magnetic fields. It is shown that the average magnetisation of the domain walls has a perpendicular component that can change dynamically depending on the parameters of the pulsed excitation. In particular, we demonstrate the formation of wave bullet-like excitations, which are generated in the domain walls and can propagate inside them during the cyclic motion of the vortex core. Based on numerical simulations we also show that, besides the core, there are four singularities formed at the corners of the pattern. The polarisation of these singularities has a direct relation to the vortex core, and can be switched dynamically by the wave bullets excited with a magnetic pulse of specific parameters. The subsequent dynamics of the Landau pattern is dependent on the particular configuration of the polarisations of the core and the singularities.

Alendronate and estrogen effects in postmenopausal women with low bone mineral density. Alendronate/Estrogen Study Group.

The bisphosphonate alendronate and conjugated equine estrogens are both widely used for the treatment of postmenopausal osteoporosis. Acting by different mechanisms, these two agents decrease bone resorption and thereby increase or preserve bone mineral density (BMD). The comparative and combined effects of these medications have not been rigorously studied. This prospective, double blind, placebo-controlled, randomized clinical trial examined the effects of oral alendronate and conjugated estrogen, in combination and separately, on BMD, biochemical markers of bone turnover, safety, and tolerability in 425 hysterectomized postmenopausal women with low bone mass. In addition, bone biopsy with histomorphometry was performed in a subset of subjects. Treatment included placebo, alendronate (10 mg daily), conjugated equine estrogen (CEE; 0.625 mg daily), or alendronate (10 mg daily) plus CEE (0.625 mg daily) for 2 yr. All of the women received a supplement of 500 mg calcium daily. At 2 yr, placebo-treated patients showed a mean 0.6% loss in lumbar spine BMD, compared with mean increases in women receiving alendronate, CEE, and alendronate plus CEE of 6.0% (P < 0.001 vs. placebo), 6.0% (P < 0.001 vs. placebo), and 8.3% (P < 0.001 vs. placebo and CEE; P = 0.022 vs. alendronate), respectively. The corresponding changes in total proximal femur bone mineral density were +4.0%, +3.4%, +4.7%, and +0.3% for the alendronate, estrogen, alendronate plus estrogen, and placebo groups, respectively. Both alendronate and CEE significantly decreased biochemical markers of bone turnover, specifically urinary N-telopeptide of type I collagen and serum bone-specific alkaline phosphatase. The alendronate plus CEE combination produced slightly greater decreases in these markers than either treatment alone, but the mean absolute values remained within the normal premenopausal range. Alendronate, alone or in combination with CEE, was well tolerated. In the subset of patients who underwent bone biopsies, histomorphometry showed normal bone histology with the expected decrease in bone turnover, which was somewhat more pronounced in the combination group. Thus, alendronate and estrogen produced favorable effects on BMD. Combined use of alendronate and estrogen produced somewhat larger increases in BMD than either agent alone and was well tolerated.

An estradiol matrix transdermal system for the prevention of postmenopausal bone loss.

OBJECTIVE: The aim of this study was to evaluate the efficacy, safety, and tolerability of 2 years' application of an estradiol matrix transdermal system for the prevention of postmenopausal bone loss. METHODS: In this multicenter, randomized, placebo-controlled, parallel-group study, 261 surgically or naturally postmenopausal women were randomized to apply the estradiol matrix transdermal system (0.025, 0.0375, 0.05, or 0.1 mg/d) or matching placebo twice a week for 2 years. The study was double blind with respect to treatment (active vs placebo) but not to the dose levels of active treatment (because of the differing sizes and shapes of the patches). In addition to receiving the assigned treatment, the 100 nonhysterectomized women received 2.5 mg medroxyprogesterone acetate daily throughout the study. RESULTS: The evaluable group (n = 259) had a mean age of 52 years and a mean duration of menopause of 32 months. Following 2 years of treatment, there were significant differences in favor of estradiol between all doses of the estradiol matrix transdermal system and placebo in terms of the percentage change from baseline in the bone mineral density (BMD) of the L1-L4 anteroposterior lumbar spine (0.1 and 0.05 mg/d, P < 0.001; 0.0375 mg/d, P = 0.024; 0.025 mg/d, P = 0.002). Percentage changes from baseline in the BMD of the femoral neck after 2 years of treatment also consistently demonstrated the efficacy of the estradiol matrix transdermal system compared with placebo (all, P < or = 0.044). The estradiol matrix transdermal system was well tolerated. CONCLUSION: The estradiol matrix transdermal system was effective in preventing postmenopausal bone loss at dosages of 0.025 to 0.1 mg/d, and had a safety profile consistent with the known effects of estrogen/progestin.

Memory of Northern Irish Catholics and Protestants for violent incidents and their explanations for the 1981 hunger strike.

The aim of this study was to examine the memory of Northern Irish Catholics (n = 20) and Protestants (n = 21) for violent events which had occurred over the previous 11 years and their explanations for those events. It was predicted that Catholics would recall more events involving Catholic deaths than Protestants and that Protestants would recall more events involving Protestant deaths than Catholics. Although Catholics were as likely as Protestants to recall incidents which resulted in Protestant deaths, Protestants were less likely than Catholics to recall incidents involving Catholic deaths. Also, there were divergent explanations for the 1981 hunger strike with most Protestants attributing responsibility to factors internal to the hunger strikers and most Catholics attributing responsibility to factors external to the hunger strikers.

Low-Radiation-Dose Modified Small Bowel CT for Evaluation of Recurrent Crohn's Disease.

Crohn's disease affects any part of the GI tract, commonly the terminal ileum. To decrease radiation exposure we developed a low-radiation-dose unenhanced CT (modified small Bowel CT, MBCT) to evaluate the small bowel using hyperdense oral contrast. Technique. MBCT was investigated in patients with pathologically proven Crohn's disease presenting with new symptoms from recurrent inflammation or stricture. After ethics board approval, 98 consecutive patients were retrospectively evaluated. Kappa values from two independent reviewers were calculated for presence of obstruction, active inflammation versus chronic stricture, and ancillary findings. Forty-two patients underwent surgery or colonoscopy within 3 months. Results. Kappa was 0.84 for presence of abnormality versus a normal exam and 0.89 for differentiating active inflammation from chronic stricture. Level of agreement for presence of skip areas, abscess formation, and fistula was 0.62, 0.75, and 0.78, respectively. In the subset with "gold standard" follow-up, there was 83% agreement. Conclusions. MBCT is a low-radiation technique with good to very good interobserver agreement for determining presence of obstruction and degree of disease activity in patients with Crohn's disease. Further investigation is required to refine parameters of disease activity compared to CT enterography and small bowel follow through.

Fracture risk remains reduced one year after discontinuation of risedronate.

UNLABELLED: One year after discontinuation of three year's treatment with risedronate, BMD decreased at the lumbar spine and femoral neck and bone turnover markers returned to control group levels. Despite these changes, the risk of new morphometric vertebral fractures remained lower in previous risedronate patients compared with previous control patients. INTRODUCTION: Differences in bisphosphonate pharmacology and pharmacokinetics could influence persistence or resolution of the effects once treatment is stopped. We investigated changes in intermediate markers--bone mineral density (BMD) and bone turnover markers (BTM)--and fracture risk after discontinuation of treatment with risedronate. METHODS: Patients who received risedronate 5 mg daily (N = 398) or placebo (N = 361) during the VERT-NA study stopped therapy per protocol after 3 years but continued taking vitamin D (if levels at study entry were low) and calcium and were reassessed one year later. RESULTS: In the year off treatment, spine BMD decreased significantly, but remained higher than baseline (p < or = 0.001) and placebo (p < 0.001), with similar findings at the femoral neck and trochanter. Urinary NTX and bone-specific alkaline phosphatase, which decreased significantly with treatment, were not significantly different from placebo after 1 year off treatment. Despite the changes in intermediate markers, the incidence of new morphometric vertebral fractures was 46% lower in the former risedronate group compared with the former placebo group (RR 0.54 [95% CI, 0.34, 0.86, p = 0.009]). CONCLUSIONS: Despite the apparent resolution of effect on BMD and BTM, the risk reduction of new vertebral fractures remained in the year after treatment with risedronate was stopped.

CRACK/project prevention: providing a social service or promoting social control?

This paper tests the arguments put forth by Morgan (2004) and several others that the CRACK/Project Prevention programme, which offers substance-abusing women a monetary incentive to choose long-term or permanent birth control, is racist and unethical. Findings from a sample of 521 participants in the programme show that the majority of women chose a birth control method that was not permanent, and race did not play a statistically significant role in explaining the birth control choices among the women. Rather, the participant's age and the number of pregnancies she had experienced were more influential. The findings suggest that the prior criticisms of the programme for targeting minority and inherently vulnerable, addicted women for sterilisation are unsupported. Women in this study appeared to follow the larger trends among women of all races and socioeconomic backgrounds in choosing permanent birth control: they were older and had more children.

Effects of risedronate treatment on vertebral and nonvertebral fractures in women with postmenopausal osteoporosis: a randomized controlled trial. Vertebral Efficacy With Risedronate Therapy (VERT) Study Group.

CONTEXT: Risedronate, a potent bisphosphonate, has been shown to be effective in the treatment of Paget disease of bone and other metabolic bone diseases but, to our knowledge, it has not been evaluated in the treatment of established postmenopausal osteoporosis. OBJECTIVE: To test the efficacy and safety of daily treatment with risedronate to reduce the risk of vertebral and other fractures in postmenopausal women with established osteoporosis. DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind, placebo-controlled trial of 2458 ambulatory postmenopausal women younger than 85 years with at least 1 vertebral fracture at baseline who were enrolled at 1 of 110 centers in North America conducted between December 1993 and January 1998. INTERVENTIONS: Subjects were randomly assigned to receive oral treatment for 3 years with risedronate (2.5 or 5 mg/d) or placebo. All subjects received calcium, 1000 mg/d. Vitamin D (cholecalciferol, up to 500 IU/d) was provided if baseline levels of 25-hydroxyvitamin D were low. MAIN OUTCOME MEASURES: Incidence of new vertebral fractures as detected by quantitative and semiquantitative assessments of radiographs; incidence of radiographically confirmed nonvertebral fractures and change from baseline in bone mineral density as determined by dual x-ray absorptiometry. RESULTS: The 2.5 mg/d of risedronate arm was discontinued after 1 year; in the placebo and 5 mg/d of risedronate arms, 450 and 489 subjects, respectively, completed all 3 years of the trial. Treatment with 5 mg/d of risedronate, compared with placebo, decreased the cumulative incidence of new vertebral fractures by 41 % (95% confidence interval [CI], 18%-58%) over 3 years (11.3 % vs 16.3%; P= .003). A fracture reduction of 65% (95% CI, 38%-81 %) was observed after the first year (2.4% vs 6.4%; P<.001). The cumulative incidence of nonvertebral fractures over 3 years was reduced by 39% (95% CI, 6%-61 %) (5.2 % vs 8.4%; P = .02). Bone mineral density increased significantly compared with placebo at the lumbar spine (5.4% vs 1.1 %), femoral neck (1.6% vs -1.2%), femoral trochanter (3.3% vs -0.7%), and midshaft of the radius (0.2% vs -1.4%). Bone formed during risedronate treatment was histologically normal. The overall safety profile of risedronate, including gastrointestinal safety, was similar to that of placebo. CONCLUSIONS: These data suggest that risedronate therapy is effective and well tolerated in the treatment of women with established postmenopausal osteoporosis.