2,919 research outputs found
Clover infertility of sheep : continuing problem
Some varieties of subterranean clover, notably Dinninup, Dwalganup and Yarloop, contain compounds which act like the female sex hormone oestrogen. These plant oestrogens, or phyto-oestrogens , interfere with the fertility of sheep and depress the percentage of lambs born.
Over the past 10 years our understanding of clover infertility has increased, and we can now gauge the extent of this residual problem. In fact, there is a widespread but low-level incidence of infertility which does not greatly affect individial farms but which has an important impact on the State\u27s sheep production
Bubbles Unbound: Bubbles of Nothing Without Kaluza-Klein
I present analytic time symmetric initial data for five dimensions describing
``bubbles of nothing'' which are asymptotically flat in the higher dimensional
sense, i.e. there is no Kaluza-Klein circle asymptotically. The mass and size
of these bubbles may be chosen arbitrarily and in particular the solutions
contain bubbles of any size which are arbitrarily light. This suggests the
solutions may be important phenomenologically and in particular I show that at
low energy there are bubbles which expand outwards, suggesting a new possible
instability in higher dimensions. Further, one may find bubbles of any size
where the only region of high curvature is confined to an arbitrarily small
volume.Comment: 27 pages, 2 figures, v2: minor changes, published versio
Fracture toughness of the cancellous bone of FNF femoral heads in relation to its microarchitecture
This study considers the relationship between microarchitecture and mechanical properties for cancellous bone specimens collected from a cohort of patients who had suffered fractured necks of femur. OP
is an acute skeletal condition with huge socioeconomic impact [1] and it is associated with changes in both bone quantity and quality [2], which affect greatly the strength and toughness of the tissue [3].Support was provided by the EPSRC (EP/K020196: Point-ofCare High Accuracy Fracture Risk Prediction), the UK Department of Transport under the BOSCOS (Bone Scanning for Occupant Safety) project, and approved by Gloucester and Cheltenham NHS Trust hospitals under ethical consent (BOSCOS – Mr. Curwen CI REC ref 01/179G)
A class of plane symmetric perfect-fluid cosmologies with a Kasner-like singularity
We prove the existence of a class of plane symmetric perfect-fluid
cosmologies with a (-1/3, 2/3, 2/3) Kasner-like singularity. These solutions of
the Einstein equations depend on two smooth functions of one space coordinate.
They are constructed by solving a symmetric hyperbolic system of Fuchsian
equations.Comment: LaTeX, 15 pages, no figures, to appear in CQG, correction to
existence proo
Effectiveness of exercise programs to reduce falls in older people with dementia living in the community: A systematic review and meta-analysis
Objective: The objective of this systematic review and meta-analysis is to evaluate the effectiveness of exercise programs to reduce falls in older people with dementia who are living in the community. Method: Peer-reviewed articles (randomized controlled trials [RCTs] and quasi-experimental trials) published in English between January 2000 and February 2014, retrieved from six electronic databases – Medline (ProQuest), CINAHL, PubMed, PsycInfo, EMBASE and Scopus – according to predefined inclusion criteria were included. Where possible, results were pooled and meta-analysis was conducted. Results: Four articles (three RCT and one single-group pre- and post-test pilot study) were included. The study quality of the three RCTs was high; however, measurement outcomes, interventions, and follow-up time periods differed across studies. On completion of the intervention period, the mean number of falls was lower in the exercise group compared to the control group (mean difference [MD] [95% confidence interval {CI}] =-1.06 [-1.67 to -0.46] falls). Importantly, the exercise intervention reduced the risk of being a faller by 32% (risk ratio [95% CI] =0.68 [0.55–0.85]). Only two other outcomes were reported in two or more of the studies (step test and physiological profile assessment). No between-group differences were observed in the results of the step test (number of steps) (MD [95% CI] =0.51 [-1.77 to 2.78]) or the physiological profile assessment (MD [95% CI] =-0.10 [-0.62 to 0.42]).Conclusion: Findings from this review suggest that an exercise program may potentially assist in preventing falls of older people with dementia living in the community. However, further research is needed with studies using larger sample sizes, standardized measurement outcomes, and longer follow-up periods, to inform evidence-based recommendations
Near-field testing of the 15-meter hoop-column antenna
A 15-m-diameter antenna was tested to verify that dimensional tolerances for acceptable performance could be achieved and to verify structural, electromagnetic, and mechanical performance predictions. This antenna utilized the hoop column structure, a gold plated molybdenum mesh reflector, and 96 control cables to adjust the reflector conformance with a paraboloid. The dimensional conformance of the antenna structure and surface was measured with metric camera and theodolites. Near field pattern data were used to assess the electromagnetic performance at five frequencies from 2.225 to 11.6 GHz. The reflector surface was adjusted to greatly improve electromagnetic performance with a finite element model and the surface measurements. Measurement results show that antenna surface figure and adjustments and electromagnetic patterns agree well with predictions
Diffraction of complex molecules by structures made of light
We demonstrate that structures made of light can be used to coherently
control the motion of complex molecules. In particular, we show diffraction of
the fullerenes C60 and C70 at a thin grating based on a standing light wave. We
prove experimentally that the principles of this effect, well known from atom
optics, can be successfully extended to massive and large molecules which are
internally in a thermodynamic mixed state and which do not exhibit narrow
optical resonances. Our results will be important for the observation of
quantum interference with even larger and more complex objects.Comment: 4 pages, 3 figure
Decreased Incidence of Periprosthetic Joint Infection in Total Hip Arthroplasty with Use of Topical Vancomycin
Background: Periprosthetic joint infections following total hip arthroplasty (THA) can cause significant patient morbidity and carry with them a substantial cost burden to the healthcare system. The purpose of this study was to assess whether the addition of topical vancomycin decreased the incidence of superficial and deep infections after primary total hip arthroplasty?  Â
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Methods: We performed a retrospective analysis of patients who underwent primary THA with (1070 hips) and without (815 hips) the use of topical vancomycin. Records were reviewed to determine incidence of PJI. Infections were categorized as deep or superficial. Medical comorbidity data was evaluated for known risk factors including diabetes, rheumatoid arthritis, and BMI. Records were further reviewed to determine surgical approach used and bacterial cause of PJI.  Â
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Results: The overall incidence of infection in the control group was 1.47% (12 hips) and significantly decreased to 0.47% (5 hips) with the addition of topical vancomycin (p=0.022). Deep infections also decreased from 0.86% (7 hips) in the control group to 0.09% (1 hip) in the vancomycin group (p=0.011). Â There was no difference in BMI or percent of patients with diabetes between groups. Â Â Â Â Â Â In all patients, regardless of vancomycin use, the incidence of infection in the direct lateral approach was higher (2.04%, 9 hips) than the anterior approach (0.055%, 8 hips)Â (p=0.004).
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Conclusions: Â We found a lower incidence of periprosthetic joint infection after THA with the addition of topical vancomycin. We also found a decreased incidence of infection in patients who had surgery through an anterior approach compared with those who had a direct lateral approach
High resolution amplitude and phase gratings in atom optics
An atom-field geometry is chosen in which an atomic beam traverses a field
interaction zone consisting of three fields, one having frequency propagating in the direction and the other two having
frequencies and propagating in the
- direction. For and , where and are positive integers and
is the pulse duration in the atomic rest frame, the atom-field interaction
results in the creation of atom amplitude and phase gratings having period . In this manner, one can use optical fields having
wavelength to produce atom gratings having periodicity much less
than .Comment: 11 pages, 14 figure
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