Fluorescence Time Delay in Multistep Auger Decay as an Internal Clock.

Differences in postcollision interaction (PCI) effects on Kr L_{3}M_{4,5}M_{4,5} Auger electron spectra were observed, depending on whether the initial photoionization occurred slightly above the K threshold or slightly above the L_{3} threshold. For the former, KL fluorescence emission most likely happens and then Auger processes due to the L_{3} hole follow. The time delay due to fluorescence causes a reduced shift of the Auger peak and tailing toward lower energy, since the Auger overtaking of the photoelectron happens later in time and at a location farther away from the ionic core, compared to the case for the simple one-step L_{3}M_{4,5}M_{4,5} Auger decay after L-shell photoionization. Time-dependent theory for PCI in multistep processes agrees well with experiment, illustrating the effect as an internal clock for the time-sequence of the dynamical process.

The Heidelberg compact electron beam ion traps.

Electron beam ion traps (EBITs) are ideal tools for both production and study of highly charged ions (HCIs). In order to reduce their construction, maintenance, and operation costs, we have developed a novel, compact, room-temperature design, the Heidelberg Compact EBIT (HC-EBIT). Four already commissioned devices operate at the strongest fields (up to 0.86 T) reported for such EBITs using permanent magnets, run electron beam currents up to 80 mA, and energies up to 10 keV. They demonstrate HCI production, trapping, and extraction of pulsed Ar16+ bunches and continuous 100 pA ion beams of highly charged Xe up to charge state 29+, already with a 4 mA, 2 keV electron beam. Moreover, HC-EBITs offer large solid-angle ports and thus high photon count rates, e.g., in x-ray spectroscopy of dielectronic recombination in HCIs up to Fe24+, achieving an electron-energy resolving power of E/ΔE > 1500 at 5 keV. Besides traditional on-axis electron guns, we have also implemented a novel off-axis gun for laser, synchrotron, and free-electron laser applications, offering clear optical access along the trap axis. We report on its first operation at a synchrotron radiation facility demonstrating the resonant photoexcitation of highly charged oxygen.

Self-induction of abortion among women accessing second-trimester abortion services in the public sector, Western Cape Province, South Africa: an exploratory study.

BACKGROUND: Despite South Africa's liberal abortion law permitting abortion on request in the first trimester and under restricted conditions for second-trimester pregnancies, the practice of unsafe self-induced abortion persists. However, the prevalence of this practice, the methods used and the reasons behind it are relatively under-researched. As part of a larger study seeking to improve abortion services in the Western Cape Province, we explored reports of prior attempts to self-induce abortion among women undergoing legal second-trimester abortion. OBJECTIVES: To describe the prevalence and methods of and factors related to unsuccessful attempts at self-induction of abortion by women presenting without complications and seeking second-trimester abortion at public health facilities in the Western Cape. METHODS: In a cross-sectional study from April to August 2010, 194 consenting women undergoing second-trimester abortion were interviewed by trained fieldworkers using structured questionnaires at four public sector facilities near Cape Town. RESULTS: Thirty-four women (17.5%; 95% confidence interval 12.7 - 23.4) reported an unsuccessful attempt to self-induce abortion during the current pregnancy before going to a facility for second-trimester abortion. No factors were significantly associated with self-induction, but a relatively high proportion of this small sample were unemployed and spoke an indigenous African language at home. A readily available herbal product called Stametta was most commonly used; other methods included taking tablets bought from unlicensed providers and using other herbal remedies. No use of physical methods was reported. CONCLUSIONS: The prevalence of unsafe self-induction of abortion is relatively high in the Western Cape. Efforts to inform women in the community about the availability of free services in the public sector and to educate them about the dangers of self-induction and unsafe providers should be strengthened to help address this public health issue.

The challenges of offering public second trimester abortion services in South Africa: health care providers' perspectives.

Around 25% of abortions in South Africa are performed in the second trimester. This study aimed to better understand what doctors, nurses and hospital managers involved in second trimester abortion care thought about these services and how they could be improved. Nineteen in-depth interviews with abortion-related service providers and managers in the Western Cape Province, South Africa, were undertaken. Data were analysed using a thematic analysis approach. Participants expressed resistance to the dilation and evacuation (D&E) procedure, as this required more active provider involvement. Medical abortion was preferred as it required less provider involvement in the abortion process. A shortage of providers willing to perform D&E resulted in most public sector services being outsourced to private sector doctors. Respondents noted an increased demand for services and a concomitant lack of infrastructure, physical space and personnel to respond to these demands, sometimes resulting in fragmented or poor quality care. At medical induction sites, most thought introducing the combined mifepristone-misoprostol regimen would improve service capacity, although they were concerned about cost. Improving contraceptive services was also seen as a much-needed intervention to improve care and prevent abortion. Ongoing training, including values clarification, as well as emotional support and team-building for providers are needed to ensure sustainable, high-quality second trimester abortion services.

A Qualitative Exploration of HIV-Positive Pregnant Women's Decision-Making Regarding Abortion in Cape Town; South Africa

HIV-positive women's abortion decisions were explored by: (i) investigating influencing factors; (ii) determining knowledge of abortion policy and public health services; and (iii) exploring abortion experiences. In-depth interviews were held with 24 HIVpositive women (15 had an abortion; 9 did not); recruited at public health facilities in Cape Town; South Africa. Negative perceptions towards HIV-positive pregnant women were reported. Women wanted abortions due to socio-economic hardship in conjunction with HIV-positive status. Respondents were generally aware that women in South Africa had a right to free abortions in public health facilities. Both positive and negative abortion experiences were described. Respondents reported no discrimination by providers due to their HIV-positive status. Most respondents reported not using contraceptives; while describing their pregnancies as `unexpected'. The majority of women who had abortions wanted to avoid another one; and would encourage other HIV-positive women to try to avoid abortion. However; most felt abortions were acceptable for HIV-positive women in some circumstances. Data suggested that stigma and discrimination affect connections between abortion; pregnancy and HIV/AIDS; and that abortion may be more stigmatised than HIV/AIDS. Study results provide important insights; and any revision of reproductive health policy; services; counselling for abortion and HIV/AIDS care should address these issues

Is CO carbon KVV Auger electron emission affected by the photoelectron?

Angular distributions (ADs) of O+ fragments from C 1s photoexcited CO detected in coincidence with carbon KVV Auger electrons emitted in the horizontal direction were measured at photon energies of 298, 305, 320, and 450 eV. At 450 eV, the ADs are polarization-independent and coincide with the molecular-frame Auger electron angular distribution. All measured ADs can be rationalized as a product of the same molecular-frame Auger electron angular distribution and the axial selectivity in the photoionization process. Thus the interaction between the photoelectron and the Auger electron for the normal Auger decay of CO can be neglected, and the two-step model is a good approximation.

Study of the dissociation of nitrous oxide following resonant excitation of the nitrogen and oxygen K-shells.

A photochemistry study on nitrous oxide making use of site-selective excitation of terminal nitrogen, central nitrogen, and oxygen 1s-->3pi excitations is presented. The resonant Auger decay which takes place following excitation can lead to dissociation of the N2O+ ion. To elucidate the nuclear dynamics, energy-resolved Auger electrons were detected in coincidence with the ionic dissociation products, and a strong dependence of the fragmentation pathways on the core-hole site was observed in the binding energy region of the first satellite states. A description based on the molecular orbitals as well as the correlation between the thermodynamical thresholds of ion formation and the first electronic states of N2O+ has been used to qualitatively explain the observed fragmentation patterns.

Revised standards for sterilisation: the changes.

The standards for the three main methods of sterilising medical devices, ethylene oxide, radiation and moist heat, have been revised. This article discusses the major changes in the requirements, which will need to be addressed to demonstrate compliance with the revised standards.

Rates of complication in first-trimester manual vacuum aspiration abortion done by doctors and mid-level providers in South Africa and Vietnam: a randomised controlled equivalence trial.

BACKGROUND: We assessed whether the safety of first-trimester manual vacuum aspiration abortion done by health-care providers who are not doctors (mid-level providers) is equivalent to that of procedures done by doctors in South Africa and Vietnam, where mid-level providers are government trained and accredited to do first-trimester abortions. METHODS: We did a randomised, two-sided controlled equivalence trial to compare rates of complication in abortions done by the two groups of providers. An a-priori margin of equivalence of 4.5% with 80% power and 95% CI (alpha=0.05) was used. 1160 women participated in South Africa and 1734 in Vietnam. Women presenting for an induced abortion at up to 12 weeks' gestation were randomly assigned to a doctor or a mid-level provider for manual vacuum aspiration and followed-up 10-14 days later. The primary outcome was complication of abortion. Complications were recorded during the abortion procedure, before discharge from the clinic, and at follow-up. Per-protocol and intention-to-treat analyses were done. This trial is registered at with the identifier . FINDINGS: In both countries, rates of complication satisfied the predetermined statistical criteria for equivalence: rates per 100 patients in South Africa were 1.4 (eight of 576) for mid-level providers and 0 for doctors (difference 1.4, 95% CI 0.4 to 2.7); in Vietnam, rates were 1.2 (ten of 824) for mid-level providers and 1.2 (ten of 812) for doctors (difference 0.0, 95% CI -1.2 to 1.1). There was one immediate complication related to analgesics. Delayed complications were caused by retained products and infection. INTERPRETATION: With appropriate government training, mid-level health-care providers can provide first trimester manual vacuum aspiration abortions as safely as doctors can.

Symmetry-dependent vibrational excitation in N 1s photoionization of N2: experiment and theory.

We have measured the vibrational structures of the N 1s photoelectron mainline and satellites of the gaseous N2 molecule with the resolution better than 75 meV. The gerade and ungerade symmetries of the core-ionized (mainline) states are resolved energetically, and symmetry-dependent angular distributions for the satellite emission allow us to resolve the Sigma and Pi symmetries of the shake-up (satellite) states. Symmetry-adapted cluster-expansion configuration-interaction calculations of the potential energy curves for the mainline and satellite states along with a Franck-Condon analysis well reproduce the observed vibrational excitation of the bands, illustrating that the theoretical calculations well predict the symmetry-dependent geometry relaxation effects. The energies of both mainline states and satellite states, as well as the splitting between the mainline gerade and ungerade states, are also well reproduced by the calculation: the splitting between the satellite gerade and ungerade states is calculated to be smaller than the experimental detection limit.

Transcriptional activation by estrogen receptor (ERalpha) and steroid receptor coactivator (SRC1) involves distinct mechanisms in yeast and mammalian cells.

Steroid receptors activate transcription in yeast cells via interactions with endogenous coactivators and/or basal factors. We examined the effects of mutations in the ligand binding domain on the transcriptional activity of ERalpha in yeast. Our results show that mutations in Helix 3 (K366A) and Helix 12 (M547A, L548A) disrupt transcriptional activity of ERalpha in yeast, as previously observed in mammalian cells. However, replacement of a conserved tyrosine residue in Helix 12 with alanine or aspartate (Y541A and Y541D), which renders ERalpha constitutively active in mammalian cells, had only a weak stimulatory effect on ligand-independent reporter activation by ERalpha in yeast. Two-hybrid interaction experiments revealed that a Y541A mutant expressed in yeast was capable of ligand-independent binding to a mammalian coactivator, suggesting that there is a subtle difference in how this mutant interacts with mammalian and yeast cofactors. We also show that the ligand-dependent activities of ERalpha and progesterone receptor (PR) in yeast cells were strongly enhanced by the human p160 protein steroid receptor coactivator (SRC1), but not by CREB-Binding Protein (CBP) or the p300/CBP associated factor (P/CAF). Although the SRC1 activation domains AD1 and AD2 are functional in yeast, deletion of these sequences only partially impaired SRC1 coactivator function in this organism; this is in contrast to similar experiments in mammalian cells. Thus SRC1 sequences involved in recruitment of CBP/p300 and Co-Activator-Associated Arginine Methyltransferase (CARM-1) in mammalian cells are not essential for its function in yeast, suggesting that SRC1 operates via distinct mechanisms in yeast and mammalian cells.

Experimental determination of the lifetime for the 2p3d(1P0) helium doubly excited state.

Two recent theoretical studies [C. Liu, Phys. Rev. A 64, 010501 (2001)]; M. Zitnik, ibid. 65, 032520 (2002)]] predict that the fluorescence lifetimes of helium doubly excited states converging to He+ N=2 should be longer than that of the He+ 2p ion state. This effect is caused by the electric field of the outer electron which, through Stark mixing, gives the inner fluorescing electron some series specific, stabilizing 2s character. We have obtained the first experimental evidence that confirms this effect by measuring the lifetime of the 2p3d(1P0) doubly excited state. This was determined to be 190+/-30 ps compared to 100 ps for the He+ 2p ion state. The measurements were performed using short pulses of synchrotron radiation to form doubly excited states and recording the arrival time of photons from fluorescence.

Meningococcal disease and social deprivation: a small area geographical study in Gwent, UK.

Although meningococcal disease is known to be linked to characteristics of individuals associated with social deprivation, there is only limited evidence of a relation with area-based measures of deprivation. In a small area geographical study, we ascertained 295 confirmed or probable cases occurring between 1996 and 1999 in the socially diverse resident population of Gwent Health Authority, equating to an average annual rate of 13.2 per 100,000. Incidence rates of meningococcal disease increased from 8.1 per 100,000 in the least deprived fifth of enumeration districts to 19.8 per 100,000 in the most deprived fifth, a relative risk of 2.4 (95% CI 1.7-3.6). In Poisson regression, the percentage change in the incidence rate arising from a unit change in the enumeration district Townsend score, was 9.4% (95% CI 6.2-12.6%). Strongest associations were found for the under 5 age group, serogroup B disease and with the overcrowding variable component of the Townsend index. Our study quantifies the strength of the relation between meningococcal disease and social deprivation at small area level and provides further evidence of the need for action to reduce health inequalities.

Increases in greenhouse forcing inferred from the outgoing longwave radiation spectra of the Earth in 1970 and 1997.

The evolution of the Earth's climate has been extensively studied, and a strong link between increases in surface temperatures and greenhouse gases has been established. But this relationship is complicated by several feedback processes-most importantly the hydrological cycle-that are not well understood. Changes in the Earth's greenhouse effect can be detected from variations in the spectrum of outgoing longwave radiation, which is a measure of how the Earth cools to space and carries the imprint of the gases that are responsible for the greenhouse effect. Here we analyse the difference between the spectra of the outgoing longwave radiation of the Earth as measured by orbiting spacecraft in 1970 and 1997. We find differences in the spectra that point to long-term changes in atmospheric CH4, CO2 and O3 as well as CFC-11 and CFC-12. Our results provide direct experimental evidence for a significant increase in the Earth's greenhouse effect that is consistent with concerns over radiative forcing of climate.

Analysis of the steroid receptor coactivator 1 (SRC1)-CREB binding protein interaction interface and its importance for the function of SRC1.

The transcriptional activity of nuclear receptors is mediated by coactivator proteins, including steroid receptor coactivator 1 (SRC1) and its homologues and the general coactivators CREB binding protein (CBP) and p300. SRC1 contains an activation domain (AD1) which functions via recruitment of CBP and and p300. In this study, we have used yeast two-hybrid and in vitro interaction-peptide inhibition experiments to map the AD1 domain of SRC1 to a 35-residue sequence potentially containing two alpha-helices. We also define a 72-amino-acid sequence in CBP necessary for SRC1 binding, designated the SRC1 interaction domain (SID). We show that in contrast to SRC1, direct binding of CBP to the estrogen receptor is weak, suggesting that SRC1 functions primarily as an adaptor to recruit CBP and p300. In support of this, we show that the ability of SRC1 to enhance ligand-dependent nuclear receptor activity in transiently transfected cells is dependent upon the integrity of the AD1 region. In contrast, the putative histone acetyltransferase domain, the Per-Arnt-Sim basic helix-loop-helix domain, the glutamine-rich domain, and AD2 can each be removed without loss of ligand-induced activity. Remarkably, a construct corresponding to residues 631 to 970, which contains only the LXXLL motifs and the AD1 region of SRC1, retained strong coactivator activity in our assays.

Community-based validation of the McCormick Toy Test.

The aim of the present study was to investigate the validity of a community-based hearing test to detect conductive hearing loss in 3-year-old children. Sixty-five children had their hearing tested using standard audiological tests at the same time as they underwent their 3-year-old health checks. The checks were performed by health visitors at community health clinics, and included the McCormick Toy Test (MCTT) for hearing. Fourteen children failed both tests and none passed the MCTT and failed the standard tests, giving a sensitivity of 100%. Forty-eight children passed both tests and three children failed the MCTT but passed the standard tests, giving a specificity of 94%. Positive predictive value was 82%. The results from this sample indicate that the MCTT may be used as a valid test for conductive hearing loss for 3-year-old children in the community setting.

Small angle X-ray scattering of wheat seed-storage proteins: alpha-, gamma- and omega-gliadins and the high molecular weight (HMW) subunits of glutenin.

Small angle X-ray scattering in solution was performed on seed-storage proteins from wheat. Three different groups of gliadins (alpha-, gamma- and omega-) and a high molecular weight (HMW) subunit of glutenin (1Bx20) were studied to determine molecular size parameters. All the gliadins could be modelled as prolate ellipsoids with extended conformations. The HMW subunit existed as a highly extended rod-like particle in solution with a length of about 69 nm and a diameter of about 6.4 nm. Specific aggregation effects were observed which may reflect mechanisms of self-assembly that contribute to the unique viscoelastic properties of wheat dough.