Total photoionization cross sections of atomic oxygen from threshold to 44.3A

The relative cross section of atomic oxygen for the production of singly charged ions has been remeasured in more detail and extended to cover the wavelength range 44.3 to 910.5 A by the use of synchrotron radiation. In addition, the contribution of multiple ionization to the cross sections has been measured allowing total photoionization cross sections to be obtained below 250 A. The results have been made absolute by normalization to previously measured data. The use of synchrotron radiation has enabled measurements of the continuum cross section to be made between the numerous autoionizing resonances that occur near the ionization thresholds. This in turn has allowed a more critical comparison of the various theoretical estimates of the cross section to be made. The series of autoionizing resonances leading to the 4-P state of the oxygen ion have been observed for the first time in an ionization type experiment and their positions compared with both theory and previous photographic recordings

Excited ionic and neutral fragments produced by dissociation of the N2(+)* H band

N I and N II fluorescent radiation was observed when N2 was irradiated by undispersed synchrotron radiation with an upper energy limit of approximately 200 eV. The excited fragments originate from dissociation of a band of excited ionic states of N2 lying between 34.7 and 44 eV

Rare-gas optics-free stable extreme-ultraviolet photon spectrometer for solar system studies

We have developed a prototype spectrometer for space applications that require long-term stable EUV photon flux measurements. In this recently developed spectrometer, the energy spectrum of the incoming photons is transformed directly into an electron energy spectrum by taking advantage of the photoelectric effect in one of several rare gases at low pressures. Using an electron energy spectrometer operating at a few electron volts, and followed by an electron multiplying detector, pulses due to individual electrons are counted. The overall efficiency of this process is essentially independent of gain drifts in the signal path, and the secular degradation of optical components that is often a problem in other techniques is avoided

Effect of Elliptically Polarized Light on the Angular Distribution of Photoelectrons

The angular distribution of photoelectrons predicted for elliptically polarized light is shown to be the same as that predicted for partially polarized light having incoherent perpendicular electric field components equal to the electric field components along the major and minor axes of the ellipse. Includes Corrigendum from J. Phys. B: Atom. Molec. Phys. 12:23 (1979), p. 3993

Total and dissociative photoionization cross sections of N2 from threshold to 107 eV

The absolute cross sections for the production of N(+) and N2(+) were measured from the dissociative ionization threshold of 115 A. In addition, the absolute photoabsorption and photoionization cross sections were tabulated between 114 and 796 A. The ionization efficiencies were also given at several discrete wave lengths between 660 and 790 A. The production of N(+) fragment ions are discussed in terms of the doubly excited N2(+) states with binding energies in the range of 24 to 44 eV

Rare-gas optics-free stable extreme-ultraviolet photon spectrometer for solar system studies

We have developed a prototype spectrometer for space applications that require long-term stable EUV photon flux measurements. In this recently developed spectrometer, the energy spectrum of the incoming photons is transformed directly into an electron energy spectrum by taking advantage of the photoelectric effect in one of several rare gases at low pressures. Using an electron energy spectrometer operating at a few electron volts, and followed by an electron multiplying detector, pulses due to individual electrons are counted. The overall efficiency of this process is essentially independent of gain drifts in the signal path, and the secular degradation of optical components that is often a problem in other techniques is avoided

Structural changes to the uterus of the dwarf ornate wobbegong shark (Orectolobus ornatus) during pregnancy

Embryos of the viviparous dwarf ornate wobbegong shark (Orectolobus ornatus) develop without a placenta, unattached to the uterine wall of their mother. Here, we present the first light microscopy study of the uterus of O. ornatus throughout pregnancy. At the beginning of pregnancy, the uterine luminal epithelium and underlying connective tissue become folded to form uterine ridges. By mid to late pregnancy, the luminal surface is extensively folded and long luminal uterine villi are abundant. Compared to the nonpregnant uterus, uterine vasculature is increased during pregnancy. Additionally, as pregnancy progresses the uterine epithelium is attenuated so that there is minimal uterine tissue separating large maternal blood vessels from the fluid that surrounds developing embryos. We conclude that the uterus of O. ornatus undergoes an extensive morphological transformation during pregnancy. These uterine modifications likely support developing embryos via embryonic respiratory gas exchange, waste removal, water balance, and mineral transfer

Collecting data for global surgical indicators: a collaborative approach in the Pacific region

© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. In 2015, the Lancet Commission on Global Surgery (LCoGS) recommended six surgical metrics to enable countries to measure their surgical and anaesthesia care delivery. These indicators have subsequently been accepted by the World Bank for inclusion in the World Development Indicators. With support from the Royal Australasian College of Surgeons and the Pacific Islands Surgical Association, 14 South Pacific countries collaborated to collect the first four of six LCoGS indicators. Thirteen countries collected all four indicators over a 6-month period from October 2015 to April 2016. Australia and New Zealand exceeded the recommended LCoGS target for all four indicators. Only 5 of 13 countries (38%) achieved 2-hour access for at least 80% of their population, with a range of 20% (Papua New Guinea and Solomon Islands) to over 65% (Fiji and Samoa). Five of 13 (38%) countries met the target surgical volume of 5000 procedures per 100 000 population, with six performing less than 1600. Four of 14 (29%) countries had at least 20 surgical, anaesthesia and obstetric providers in their workforce per 100 000 population, with a range of 0.9 (Timor Leste) to 18.5 (Tuvalu). Perioperative mortality rate was reported by 13 of 14 countries, and ranged from 0.11% to 1.0%. We believe it is feasible to collect global surgery indicators across the South Pacific, a diverse geographical region encompassing high-income and low-income countries. Such metrics will allow direct comparison between similar nations, but more importantly provide baseline data that providers and politicians can use in advocacy national health planning