Fabrication of intense neutron sources for medical applications

Simulated sources containing $sup 252$Cf equivalents of 0.1 to 1.0 milligrams were prepared. Samarium was used as the simulant in a modified chemical plating technique similar to that used to prepare palladium-californium oxide cermet for industrial applications. The length of the platinum-10 percent iridium doubly encapsulated source with its protective sheath is 0.545 in. (14.1 mm). Outside dia of the source, including its sheath, is 0.109 in. (2.8 mm). Existing ''Brachytrons'' can accommodate this source form. This capsule system will withstand internal gas pressures from helium due to alpha decay and fission gases from a 1 mg $sup 252$Cf source after ten years if the source is subjected to a maximum temperature of 800$sup 0$C, the theoretical temperature of an accidental fire. Under these conditions the safety factor is 3. The capsule system is being tested with tracer amounts of $sup 252$Cf to ensure that it will withstand adverse service conditions as well as tests specified for Special Form Materials. (auth

The Symptoms of Varicose Veins: Difficult to Determine and Difficult to Study

ObjectivesTo investigate the activities which may exacerbate symptoms in patients with varicose veins.MethodsQuestionnaires sent to patients before clinics and at least six months later.ResultsBoth questionnaires were returned by 149 of 203 patients (74%) but only 124 contained adequate data for comparison – 55 from patients who had surgical treatment and 69 who had no surgery. At initial presentation, worsening of discomfort attributed to varicose veins was common during (58%) or after (48%) standing and in hot weather (44%), but less when sitting with the feet down (31%), and after (31%) or when walking (19%). Surgery significantly reduced the total number of symptoms reported by patients at follow-up (p<0.02). However, none of the symptoms reported during specific activities was significantly lessened by surgery compared with no treatment – possibly because the attrition of patients during the study resulted in small numbers for analysis.ConclusionsSymptoms are a common indication for treating varicose veins and it is therefore important to be sure that they are due to the veins, rather than other causes. This report highlights traditional and logical questions which may help to identify symptoms caused by varicose veins but illustrates the difficulty of validating them

Effects of Methylene Blue and Polyethelene Glycol on Facial Nerve Axotomy Recovery

poster abstractInjury and disease are common factors affecting peripheral nerves and can lead to loss of function. Recovery time after an injury is slow and not very efficient in humans. Treatment methods involving methylene blue (MB) and polyethylene glycol (PEG) have shown combinational effects in sciatic nerve axotomies. We are using behavior analysis of eye blink reflex and vibrissae orientation and movement as a measurement of rate of functional recovery. We will have treatment groups of both cut and crush rats. For each group we will be testing the effect of PEG/MB or no treatment control groups. The results of these treatment groups are significant to finding treatment options for clinical use

High-Spin States in Nuclei Excited Via the (p,n) Reactions

Supported by the National Science Foundation and Indiana Universit

The PL calibration for Milky Way Cepheids and its implications for the distance scale

The rationale behind recent calibrations of the Cepheid PL relation using the Wesenheit formulation is reviewed and reanalyzed, and it is shown that recent conclusions regarding a possible change in slope of the PL relation for short-period and long-period Cepheids are tied to a pathological distribution of HST calibrators within the instability strip. A recalibration of the period-luminosity relation is obtained using Galactic Cepheids in open clusters and groups, the resulting relationship, described by log L/L_sun = 2.415(+-0.035) + 1.148(+-0.044)log P, exhibiting only the moderate scatter expected from color spread within the instability strip. The relationship is confirmed by Cepheids with HST parallaxes, although without the need for Lutz-Kelker corrections, and in general by Cepheids with revised Hipparcos parallaxes, albeit with concerns about the cited precisions of the latter. A Wesenheit formulation of Wv = -2.259(+-0.083) - 4.185(+-0.103)log P for Galactic Cepheids is tested successfully using Cepheids in the inner regions of the galaxy NGC 4258, confirming the independent geometrical distance established for the galaxy from OH masers. Differences between the extinction properties of interstellar and extragalactic dust may yet play an important role in the further calibration of the Cepheid PL relation and its application to the extragalactic distance scale.Comment: Accepted for Publication (Astrophysics & Space Science

The environmental stress sensitivities of pathogenic Candida species, including Candida auris, and implications for their spread in the hospital setting

We are grateful to Dr. David Stead, Evelyn Argo and Craig Pattison (Aberdeen Proteomics Core Facility) for their expert identification of Candida isolates by MALDI ToF MS, and to Dr Jill King and our colleagues in the Aberdeen Fungal Group for their helpful advice. AJPB and NARG were supported by a programme grant from the Medical Research Council [www.mrc.ac.uk] (grant number MR/M026663/1) and by the Medical Research Council Centre for Medical Mycology and the University of Aberdeen (grant number MR/N006364/1). AJPB was also supported by the UK Biotechnology and Biological Research Council [www.bbsrc.ac.uk] (grant numbers BB/F00513X/1, BB/P020119/1), and AWW by the Scottish Government’s Rural and Environment Science and Analytical Services (RESAS) division. NARG was also supported by grants from the Wellcome Trust [www.wellcome.ac.uk] (grant numbers 075470, 086827, 093378, 097377, 099197, 101873, 102705, 200208). DMM was supported by National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) [www.nc3rs.org.uk] (grant numbers NC/S001557/1 and NC/N002482/1) and the UK Biotechnology and Biological Research Council [www.bbsrc.ac.uk] (grant number BB/P02050X/1). HH was supported by the John Duthie Scholarship from the University of Aberdeen’s Development Trust. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Multi-Periodic Oscillations in Cepheids and RR Lyrae-Type Stars

Classical Cepheids and RR Lyrae-type stars are usually considered to be textbook examples of purely radial, strictly periodic pulsators. Not all the variables, however, conform to this simple picture. In this review I discuss different forms of multi-periodicity observed in Cepheids and RR Lyrae stars, including Blazhko effect and various types of radial and nonradial multi-mode oscillations.Comment: Proceedings of the 20th Stellar Pulsation Conference Series: "Impact of new instrumentation & new insights in stellar pulsations", 5-9 September 2011, Granada, Spai