Electron-based crystalline undulator

We discuss the features of a crystalline undulator of the novel type based on the effect of a planar channeling of ultra-relativistic electrons in a periodically bent crystals. It is demonstrated that an electron-based undulator is feasible in the tens of GeV range of the beam energies, which is noticeably higher than the energy interval allowed in a positron-based undulator. Numerical analysis of the main parameters of the undulator as well as the characteristics of the emitted undulator radiation is carried out for 20 and 50 GeV electrons channeling in diamond and silicon crystals along the (111) crystallographic planes.Comment: 16 pages, 8 figures, Latex, IOP styl

The physical properties of AM CVn stars: new insights from Gaia DR2

AM CVn binaries are hydrogen deficient compact binaries with an orbital period in the 5-65 min range and are predicted to be strong sources of persistent gravitational wave radiation. Using Gaia Data Release 2, we present the parallaxes and proper motions of 41 out of the 56 known systems. Compared to the parallax determined using the HST Fine Guidance Sensor we find that the archetype star, AM CVn, is significantly closer than previously thought. This resolves the high luminosity and mass accretion rate which models had difficulty in explaining. Using Pan-STARRS1 data we determine the absolute magnitude of the AM CVn stars. There is some evidence that donor stars have a higher mass and radius than expected for white dwarfs or that the donors are not white dwarfs. Using the distances to the known AM CVn stars we find strong evidence that a large population of AM CVn stars have still to be discovered. As this value sets the background to the gravitational wave signal of LISA, this is of wide interest. We determine the mass transfer rate for 15 AM CVn stars and find that the majority have a rate significantly greater than expected from standard models. This is further evidence that the donor star has a greater size than expected.Comment: Accepted by A&A in main journa

Genomic dissection of whole-plant responses to water deficit in durum wheat × wild emmer wheat RIL population

In this article we examine trends in age homogamy in first marriages in the Netherlands since 1942.... We analyze population data collected by Statistics Netherlands. Controlling for the age distribution of first-marrying men and women, chances are greatest to have married a partner of the same age. These relative chances decrease with rising age at marriage, and increase over historical time. The association between spouses' ages in age-divergent marriages is greater when the husband is older than his wife. This asymmetry in the association decreased until 1970, but increased up until 1994

Dissection of powdery mildew resistance uncover different resistance types in the Triticum turgidum L. gene pool

BACKGROUND: The aim of the present study was to compare the clinical and cosmetic results of transvaginal hybrid cholecystectomy (TVC), single-port cholecystectomy (SPC), and conventional laparoscopic cholecystectomy (CLC). Recently, single-incision laparoscopic surgery and natural orifice transluminal endoscopic surgery have been developed as minimally invasive alternatives for CLC. Few comparative studies have been reported. METHODS: Female patients with symptomatic gallstone disease who were treated in 2011 with SPC, TVC, or CLC were entered into a database. Patients were matched for age, body mass index, and previous abdominal surgery. After the operation all patients received a survey with questions about recovery, cosmesis, and body image. Results : A total of 90 patients, 30 in each group, were evaluated. Median operative time for CLC was significantly shorter (p < 0.001). There were no major complications. Length of hospital stay, postoperative pain, and postoperative complications were not significantly different. The results for cosmesis and body image after the transvaginal approach were significantly higher. None of the sexually active women observed postoperative dyspareunia. CONCLUSIONS: Both SPC and TVC are feasible procedures when performed in selected patients. CLC is a faster procedure, but other clinical outcomes and complication rates were similar. SPC, and especially TVC, offer a better cosmetic result. Randomized trials are needed to specify the role of SPC and TVC in the treatment of patients with symptomatic gallstone disease

Formalism for Multiphoton Plasmon Excitation in Jellium Clusters

We present a new formalism for the description of multiphoton plasmon excitation processes in jellium clusters. By using our method, we demonstrate that, in addition to dipole plasmon excitations, the multipole plasmons (quadrupole, octupole, etc) can be excited in a cluster by multiphoton absorption processes, which results in a significant difference between plasmon resonance profiles in the cross sections for multiphoton as compared to single-photon absorption. We calculate the cross sections for multiphoton absorption and analyse the balance between the surface and volume plasmon contributions to multipole plasmons.Comment: 29 pages, 1 figur