Hardy-Carleman Type Inequalities for Dirac Operators

General Hardy-Carleman type inequalities for Dirac operators are proved. New inequalities are derived involving particular traditionally used weight functions. In particular, a version of the Agmon inequality and Treve type inequalities are established. The case of a Dirac particle in a (potential) magnetic field is also considered. The methods used are direct and based on quadratic form techniques

The Nonpenetrating Telescopic Sham Needle May Blind Patients with Different Characteristics and Experiences When Treated by Several Therapists

Background. Little is known which factors influence the blinding in acupuncture studies. Aim. To investigate if blinding varied between patients with different characteristics receiving verum or sham acupuncture. Methods. We randomised cancer patients to verum (n = 109) or sham acupuncture (n = 106) with a nonpenetrating telescopic sham needle for nausea. Level of blinding was compared between different sub-groups of patients using Bang's blinding index (BI) ranged −1 to 1 (−1 = all state the opposite treatment, 1 = all identify treatment). Results. Most patients in the verum (74 of 95; 78%, BI 0.72) and the sham (68 of 95; 72%, BI −0.60). acupuncture group believed they had received verum acupuncture. The probability for a patient to believe he/she received verum acupuncture was related to the received needling type (P = .003) and to the patient's belief in received treatment effects (P = .008). Hospital (P = .425), therapist (P = .434), previous acupuncture experience (P = .578), occurrence of nausea (P = .157), gender (P = .760), and age (P = .357) did not affect blinding. Conclusions. Blinding was successfully achieved irrespective of age, gender, acupuncture experience, treatment effect, or in which hospital or by which therapist the patient received treatment. Patients with higher belief in the effect of the treatment were more likely to believe they had received verum acupuncture

Getting the Grip on Nonspecific Treatment Effects: Emesis in Patients Randomized to Acupuncture or Sham Compared to Patients Receiving Standard Care

Background: It is not known whether or not delivering acupuncture triggers mechanisms cited as placebo and if acupuncture or sham reduces radiotherapy-induced emesis more than standard care. Methodology/Principal Findings: Cancer patients receiving radiotherapy over abdominal/pelvic regions were randomized to verum (penetrating) acupuncture (n = 109; 99 provided data) in the alleged antiemetic acupuncture point PC6 or sham acupuncture (n = 106; 101 provided data) performed with a telescopic non-penetrating needle at a sham point 2-3 times/week during the whole radiotherapy period. The acupuncture cohort was compared to a reference cohort receiving standard care (n = 62; 62 provided data). The occurrence of emesis in each group was compared after a mean dose of 27 Gray. Nausea and vomiting were experienced during the preceding week by 37 and 8% in the verum acupuncture group, 38 and 7% in the sham acupuncture group and 63 and 15% in the standard care group, respectively. The lower occurrence of nausea in the acupuncture cohort (verum and sham) compared to patients receiving standard care (37% versus 63%, relative risk (RR) 0.6, 95 % confidence interval (CI) 0.5-0.8) was also true after adjustment for potential confounding factors for nausea (RR 0.8, CI 0.6 to 0.9). Nausea intensity was lower in the acupuncture cohort (78% no nausea, 13% a little, 8% moderate, 1% much) compared to the standard care cohort (52% no nausea, 32% a little, 15% moderate, 2% much) (p = 0.002). The acupuncture cohort expected antiemetic effects from their treatment (95%). Patients who expected nausea had increased risk for nausea compared to patients who expected low risk for nausea (RR 1.6; Cl 1.2-2.4). Conclusions/Significance: Patients treated with verum or sham acupuncture experienced less nausea and vomiting compared to patients receiving standard care, possibly through a general care effect or due to the high level of patient expectancy.Original Publication:Anna Enblom, Mats Lekander, Mats Hammar, Anna Johnsson, Erik Onelov, Martin Ingvar, Gunnar Steineck and Sussanne Börjeson, Getting the Grip on Nonspecific Treatment Effects: Emesis in Patients Randomized to Acupuncture or Sham Compared to Patients Receiving Standard Care, 2011, PLOS ONE, (6), 3, .http://dx.doi.org/10.1371/journal.pone.0014766Licensee: Public Library of Science (PLoS)http://www.plos.org

Application of Fastsim with variable coefficient of friction using twin disc experimental measurements

In the field of railway simulation, it is a general assumption to consider the coefficient of friction as a known and constant value. This hypothesis is clearly not correct as friction is a consequence of the operating conditions (an output, not an input) and many factors can cause friction coefficient to change. In this paper, numerical algorithms based on the simplified theory of Kalker (Fastsim) and capable of modelling variable friction are studied and improved to match experimental measurements. Experimental creep curves from twin disc measurements are used to extract the friction parameters required by the numerical algorithms. Different friction functions are tested to correlate the effect of the contaminants and the pressure on the coefficient of friction. Finally, two examples are shown to highlight the differences between modelling the wheel–rail contact with variable or constant coefficient of friction and their implications in the estimation of the interaction forces and wear.This research was supported by Universitat Politecnica de Valencia (Spain).Rovira Cardete, A.; Roda Buch, A.; Lewis, R.; Marshall, M. (2012). Application of Fastsim with variable coefficient of friction using twin disc experimental measurements. Wear. 274-275:109-126. doi:10.1016/j.wear.2011.08.019S109126274-27