Mixtures of Bose gases under rotation

We examine the rotational properties of a mixture of two Bose gases. Considering the limit of weak interactions between the atoms, we investigate the behavior of the system under a fixed angular momentum. We demonstrate a number of exact results in this many-body system.Comment: 4 pages, RevTex, 6 figure

Metastability of persistent currents in trapped gases of atoms

We examine the conditions that give rise to metastable, persistent currents in a trapped Bose-Einstein condensate. A necessary condition for the stability of persistent currents is that the trapping potential is not a monotonically increasing function of the distance from the trap center. Persistent currents also require that the interatomic interactions are sufficiently strong and repulsive. Finally, any off-center vortex state is shown to be unstable, while a driven gas shows hysteresis.Comment: 7 pages, RevTex, 5 figure

No reduction in instrumental vaginal births and no increased risk for adverse perineal outcome in nulliparous women giving birth on a birth seat: results of a Swedish randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>The WHO advises against recumbent or supine position for longer periods during labour and birth and states that caregivers should encourage and support the woman to take the position in which she feels most comfortable. It has been suggested that upright positions may improve childbirth outcomes and reduce the risk for instrumental delivery; however RCTs of interventions to encourage upright positions are scarce. The aim of this study was to test, by means of a randomized controlled trial, the hypothesis that the use of a birthing seat during the second stage of labor, for healthy nulliparous women, decreases the number of instrumentally assisted births and may thus counterbalance any increase in perineal trauma and blood loss.</p> <p>Methods</p> <p>A randomized controlled trial in Sweden where 1002 women were randomized to birth on a birth seat (experimental group) or birth in any other position (control group). Data were collected between November 2006 and July 2009. The primary outcome measurement was the number of instrumental deliveries. Secondary outcome measurements included perineal lacerations, perineal edema, maternal blood loss and hemoglobin. Analysis was by intention to treat.</p> <p>Results</p> <p>The main findings of this study were that birth on the birth seat did not reduce the number of instrumental vaginal births, there was an increase in blood loss between 500 ml and 1000 ml in women who gave birth on the seat but no increase in bleeding over 1000 ml and no increase in perineal lacerations or perineal edema.</p> <p>Conclusions</p> <p>The birth seat did not reduce the number of instrumental vaginal births. The study confirmed an increased blood loss 500 ml - 1000 ml but not over 1000 ml for women giving birth on the seat. Giving birth on a birth seat caused no adverse consequences for perineal outcomes and may even be protective against episiotomies.</p> <p>Trial registration number</p> <p>ClinicalTrials.gov.ID: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01182038">NCT01182038</a></p

No reduction in instrumental vaginal births and no increased risk for adverse perineal outcome in nulliparous women giving birth on a birth seat: results of a Swedish randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>The WHO advises against recumbent or supine position for longer periods during labour and birth and states that caregivers should encourage and support the woman to take the position in which she feels most comfortable. It has been suggested that upright positions may improve childbirth outcomes and reduce the risk for instrumental delivery; however RCTs of interventions to encourage upright positions are scarce. The aim of this study was to test, by means of a randomized controlled trial, the hypothesis that the use of a birthing seat during the second stage of labor, for healthy nulliparous women, decreases the number of instrumentally assisted births and may thus counterbalance any increase in perineal trauma and blood loss.</p> <p>Methods</p> <p>A randomized controlled trial in Sweden where 1002 women were randomized to birth on a birth seat (experimental group) or birth in any other position (control group). Data were collected between November 2006 and July 2009. The primary outcome measurement was the number of instrumental deliveries. Secondary outcome measurements included perineal lacerations, perineal edema, maternal blood loss and hemoglobin. Analysis was by intention to treat.</p> <p>Results</p> <p>The main findings of this study were that birth on the birth seat did not reduce the number of instrumental vaginal births, there was an increase in blood loss between 500 ml and 1000 ml in women who gave birth on the seat but no increase in bleeding over 1000 ml and no increase in perineal lacerations or perineal edema.</p> <p>Conclusions</p> <p>The birth seat did not reduce the number of instrumental vaginal births. The study confirmed an increased blood loss 500 ml - 1000 ml but not over 1000 ml for women giving birth on the seat. Giving birth on a birth seat caused no adverse consequences for perineal outcomes and may even be protective against episiotomies.</p> <p>Trial registration number</p> <p>ClinicalTrials.gov.ID: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01182038">NCT01182038</a></p

The ab initio no-core shell model

This contribution reviews a number of applications of the ab initio no-core shell model (NCSM) within nuclear physics and beyond. We will highlight a nuclear-structure study of the A = 12 isobar using a chiral NN + 3NF interaction. In the spirit of this workshop we will also mention the new development of the NCSM formalism to describe open channels and to approach the problem of nuclear reactions. Finally, we will illustrate the universality of the many-body problem by presenting the recent adaptation of the NCSM effective-interaction approach to study the many-boson problem in an external trapping potential with short-range interactions.Comment: 4 pages. Article based on the presentation by C. Forssen at the Fifth Workshop on Critical Stability, Erice, Sicily. Published in Few-Body System

Detection of Babesia divergens in southern Norway by using an immunofluorescence antibody test in cow sera

<p>Abstract</p> <p>Background</p> <p>The incidence of bovine babesiosis, caused by <it>Babesia divergens </it>(Apicomplexa: Piroplasmida) has decreased markedly since the 1930 s, but may re-emerge as a consequence of climate change and changes in legislation and pasturing practices. This is a potentially serious disease, with both economical and animal welfare consequences. Therefore, there is a need to survey the distribution of <it>B. divergens</it>.</p> <p>Methods</p> <p>We tested sera from 306 healthy pastured cows from 24 farms along the southern Norwegian coast by using an indirect immunofluorescence IgG antibody test (IFAT). Fractions of seropositive cows were compared by calculating 95% CI.</p> <p>Results</p> <p>The results of this test showed that 27% of the sera were positive for <it>B. divergens </it>antibodies. The fraction of antibody-positive sera that we detected showed a two-humped distribution, with a high fraction of positives being found in municipalities in the western and eastern parts of the study area, while the municipalities between these areas had few or no positive serum samples.</p> <p>Conclusions</p> <p>Neither the farmers' observations nor the Norwegian Dairy Herd Recording System give an adequate picture of the distribution of bovine babesiosis. Serological testing of cows by using IFAT is a convenient way of screening for the presence of <it>B. divergens </it>in an area.</p

Constraining photon-axion oscillations using quasar spectra

Using quasar spectra from the SDSS survey, we constrain the possibility of photon-axion oscillations as a source of dimming of high redshift objects. Such a process has been suggested as an explanation of the apparent faintness of distant Type Ia supernovae. For most combinations of magnetic field strengths and plasma densities along the line of sight, large beam attenuations in broad band filters would also lead to significant differential attenuation, not observed in the quasar sample. However, this conservative study does not exclude the possibility of 0.1 mag dimming of Type Ia supernovae for average plasma densities n_e = 10^(-8) cm^(-3). NIR and MIR spectroscopic studies of high-z sources may be used put further constrains or provide indirect evidence for the existence of a very light axion.Comment: 14 pages, 8 figure

Effective-interaction approach to the many-boson problem

We show that the convergence behavior of the many-body numerical diagonalization scheme for strongly interacting bosons in a trap can be significantly improved by the Lee-Suzuki method adapted from nuclear physics: One can construct an effective interaction that acts in a space much smaller than the original Hilbert space. In particular for short-ranged forces and strong correlations, the method offers a good estimate of the energy and the excitation spectrum, at a computational cost several orders of magnitude smaller than that required by the standard method.Comment: 5 pages, 4 figure