The dynamics of vortex generation in superfluid 3He-B

A profound change occurs in the stability of quantized vortices in externally applied flow of superfluid 3He-B at temperatures ~ 0.6 Tc, owing to the rapidly decreasing damping in vortex motion with decreasing temperature. At low damping an evolving vortex may become unstable and generate a new independent vortex loop. This single-vortex instability is the generic precursor to turbulence. We investigate the instability with non-invasive NMR measurements on a rotating cylindrical sample in the intermediate temperature regime (0.3 - 0.6) Tc. From comparisons with numerical calculations we interpret that the instability occurs at the container wall, when the vortex end moves along the wall in applied flow.Comment: revised & extended version. Journal of Low Temperature Physics, accepted (2008

Effect of age, sex and gender on pain sensitivity: A narrative review

© 2017 Eltumi And Tashani. Introduction: An increasing body of literature on sex and gender differences in pain sensitivity has been accumulated in recent years. There is also evidence from epidemiological research that painful conditions are more prevalent in older people. The aim of this narrative review is to critically appraise the relevant literature investigating the presence of age and sex differences in clinical and experimental pain conditions. Methods: A scoping search of the literature identifying relevant peer reviewed articles was conducted on May 2016. Information and evidence from the key articles were narratively described and data was quantitatively synthesised to identify gaps of knowledge in the research literature concerning age and sex differences in pain responses. Results: This critical appraisal of the literature suggests that the results of the experimental and clinical studies regarding age and sex differences in pain contain some contradictions as far as age differences in pain are concerned. While data from the clinical studies are more consistent and seem to point towards the fact that chronic pain prevalence increases in the elderly findings from the experimental studies on the other hand were inconsistent, with pain threshold increasing with age in some studies and decreasing with age in others. Conclusion: There is a need for further research using the latest advanced quantitative sensory testing protocols to measure the function of small nerve fibres that are involved in nociception and pain sensitivity across the human life span. Implications: Findings from these studies should feed into and inform evidence emerging from other types of studies (e.g. brain imaging technique and psychometrics) suggesting that pain in the older humans may have unique characteristics that affect how old patients respond to intervention

The Earth: Plasma Sources, Losses, and Transport Processes

This paper reviews the state of knowledge concerning the source of magnetospheric plasma at Earth. Source of plasma, its acceleration and transport throughout the system, its consequences on system dynamics, and its loss are all discussed. Both observational and modeling advances since the last time this subject was covered in detail (Hultqvist et al., Magnetospheric Plasma Sources and Losses, 1999) are addressed

Parotid Sparing Study in Head and Neck Cancer Patients Receiving Bilateral Radiation Therapy: One-year Results

Many patients with head and neck cancers receive radiation therapy as part of their treatment which frequently causes considerable morbidity, including various degrees of permanent salivary gland dysfunction. Three-dimensional treatment planning [3-DTP] and conformational dose delivery constitute a new therapeutic modality that conforms the high-dose radiation volume to the shape of the tumor volume while minimizing the dose to tissue that is not at risk of containing cancer. The treatment volumes for head and neck tumors as well as parotid glands can be well-defined on cross-sectional CT imaging techniques. The purpose of this investigation is to determine if 3-DTP and conformational dose-delivery could minimize radiation dose and salivary gland dysfunction to contralateral parotid glands in patients with head and neck cancers. Eleven patients with head and neck cancers who required bilateral radiation therapy were treated with 3-DTP. Unstimulated and stimulated bilateral parotid saliva was collected prior to radiotherapy, weekly during treatment, and 1, 3, 6, and 12 months after the completion of radiotherapy. Treated parotid glands received an average dose of 5745 cGy, while spared glands received only 1986 cGy (p < 0.0001). Unstimulated and stimulated parotid flow rates decreased dramatically in treated glands after the initiation of radiotherapy, remained at extremely low rates without any improvements, and were significantly lower at 1 year after radiotherapy compared with baseline. Conversely, parotid flow rates in spared glands underwent mild changes during radiotherapy and were approximately 50% of baseline values. The results of this study suggest that with the use of 3-DTP, contralateral parotid gland function can be partially preserved for at least 1 year in patients with head and neck cancers requiring bilateral radiation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67828/2/10.1177_00220345970760031401.pd