Sensitivity studies for r-process nucleosynthesis in three astrophysical scenarios

In rapid neutron capture, or r-process, nucleosynthesis, heavy elements are built up via a sequence of neutron captures and beta decays that involves thousands of nuclei far from stability. Though we understand the basics of how the r-process proceeds, its astrophysical site is still not conclusively known. The nuclear network simulations we use to test potential astrophysical scenarios require nuclear physics data (masses, beta decay lifetimes, neutron capture rates, fission probabilities) for all of the nuclei on the neutron-rich side of the nuclear chart, from the valley of stability to the neutron drip line. Here we discuss recent sensitivity studies that aim to determine which individual pieces of nuclear data are the most crucial for r-process calculations. We consider three types of astrophysical scenarios: a traditional hot r-process, a cold r-process in which the temperature and density drop rapidly, and a neutron star merger trajectory.Comment: 8 pages, 4 figures, submitted to the Proceedings of the International Nuclear Physics Conference (INPC) 201

Strains of stem and leaf rust on wheat in Western Australia since 1951

THE most important wheat rust in Western Australia is stem rust, Leaf rust occurs infrequently and has not been known to cause serious damage

A reevaluation of achromatic spatio-temporal vision: nonoriented filters are monocular, they adapt, and can be used for decision making at high flicker speeds

Masking, adaptation, and summation paradigms have been used to investigate the characteristics of early spatio-temporal vision. Each has been taken to provide evidence for (i) oriented and (ii) nonoriented spatial-filtering mechanisms. However, subsequent findings suggest that the evidence for nonoriented mechanisms has been misinterpreted: those experiments might have revealed the characteristics of suppression (eg, gain control), not excitation, or merely the isotropic subunits of the oriented detecting mechanisms. To shed light on this, we used all three paradigms to focus on the ‘high-speed’ corner of spatio-temporal vision (low spatial frequency, high temporal frequency), where cross-oriented achromatic effects are greatest. We used flickering Gabor patches as targets and a 2IFC procedure for monocular, binocular, and dichoptic stimulus presentations. To account for our results, we devised a simple model involving an isotropic monocular filter-stage feeding orientation-tuned binocular filters. Both filter stages are adaptable, and their outputs are available to the decision stage following nonlinear contrast transduction. However, the monocular isotropic filters (i) adapt only to high-speed stimuli—consistent with a magnocellular subcortical substrate—and (ii) benefit decision making only for high-speed stimuli (ie, isotropic monocular outputs are available only for high-speed stimuli). According to this model, the visual processes revealed by masking, adaptation, and summation are related but not identical

Study Protocol – Improving Access to Kidney Transplants (IMPAKT): A detailed account of a qualitative study investigating barriers to transplant for Australian Indigenous people with end-stage kidney disease

<p>Abstract</p> <p>Background</p> <p>Indigenous Australians are slightly more than 2% of the total Australian population however, in recent years they have comprised between 6 and 10% of new patients beginning treatment for end-stage kidney disease (ESKD). Although transplant is considered the optimal form of treatment for many ESKD patients there is a pronounced disparity between the rates at which Indigenous ESKD patients receive transplants compared with their non-Indigenous counterparts. The IMPAKT (Improving Access to Kidney Transplants) Interview study investigated reasons for this disparity through a large scale, in-depth interview study involving patients, nephrologists and key decision-making staff at selected Australian transplant and dialysis sites.</p> <p>Methods</p> <p>The design and conduct of the study reflected the multi-disciplinary membership of the core IMPAKT team. Promoting a participatory ethos, IMPAKT established partnerships with a network of hospital transplant units and hospital dialysis treatment centres that provide treatment to the vast majority of Indigenous patients across Australia. Under their auspices, the IMPAKT team conducted in-depth interviews in 26 treatment/service centres located in metropolitan, regional and remote Australia. Peer interviewing supported the engagement of Indigenous patients (146), and nephrologists (19). In total IMPAKT spoke with Indigenous and non-Indigenous patients (241), key renal nursing and other (non-specialist) staff (95) and a small number of relevant others (28). Data analysis was supported by QSR software. At each site, IMPAKT also documented educational programs and resources, mapped an hypothetical ‘patient journey’ to transplant through the local system and observed patient care and treatment routines.</p> <p>Discussion</p> <p>The national scope, inter-disciplinary approach and use of qualitative methods in an investigation of a significant health inequality affecting Indigenous people is, we believe, an Australian first. An exceptionally large cohort of Indigenous participants provided evaluative comment on their health services in relation to dialysis and transplant. Additionally, the data includes extensive parallel commentary from a cohort of specialists, nurses and other staff. The study considers a ‘patient journey’ to transplant within a diverse range of Australian treatment centre/workplace settings. The IMPAKT Interview study protocol may contribute to improvements in multi-disciplinary, flexible design health services research with hard to reach or vulnerable populations in Australia and elsewhere.</p

Potentially preventable infant and child deaths identified at autopsy; findings and implications

Purpose The purpose of the study was to determine the proportion of pediatric deaths investigated by HM Coronial autopsy which were potentially preventable deaths due to treatable natural disease, and what implications such findings may have for health policies to reduce their occurrence. Methods A retrospective study of 1779 autopsies of individuals between 7 days and 14 years of age requested by HM Coroner, taking place in one specialist pediatric autopsy center, was undertaken. Cases were included if they involved a definite natural disease process in which appropriate recognition and treatment was likely to have affected their outcome. Strict criteria were used and cases were excluded where the individual had any longstanding condition which might have predisposed them to, or altered the recognition of, acute illness, or its response to therapy. Results Almost 8 % (134/1779) of the study group were potentially preventable deaths as a result of natural disease, the majority occurring in children younger than 2 years of age. Most individuals reported between 1 and 7 days of symptoms before their death, and the majority had sought medical advice during this period, including from general practitioners within working hours, and hospital emergency departments. Of those who had sought medical attention, around one-third had done so more than once (28 %, 15/53). Sepsis and pneumonia accounted for the majority of deaths (46 and 34 % respectively), with all infections (sepsis, pneumonia and meningitis) accounting for 110/134 (82 %). Conclusion Around 10 % of pediatric deaths referred to HM Coroner are potentially preventable, being the result of treatable natural acute illnesses. In many cases medical advice had been sought during the final illness. The results highlight how a review of autopsy data can identify significant findings with the potential to reduce mortality, and the importance of centralized investigation and reporting of pediatric deaths

Temporal Integration of Movement: The Time-Course of Motion Streaks Revealed by Masking

Temporal integration in the visual system causes fast-moving objects to leave oriented ‘motion streaks’ in their wake, which could be used to facilitate motion direction perception. Temporal integration is thought to occur over 100 ms in early cortex, although this has never been tested for motion streaks. Here we compare the ability of fast-moving (‘streaky’) and slow-moving fields of dots to mask briefly flashed gratings either parallel or orthogonal to the motion trajectory. Gratings were presented at various asynchronies relative to motion onset (from to ms) to sample the time-course of the accumulating streaks. Predictions were that masking would be strongest for the fast parallel condition, and would be weak at early asynchronies and strengthen over time as integration rendered the translating dots more streaky and grating-like. The asynchrony where the masking function reached a plateau would correspond to the temporal integration period. As expected, fast-moving dots caused greater masking of parallel gratings than orthogonal gratings, and slow motion produced only modest masking of either grating orientation. Masking strength in the fast, parallel condition increased with time and reached a plateau after 77 ms, providing an estimate of the temporal integration period for mechanisms encoding motion streaks. Interestingly, the greater masking by fast motion of parallel compared with orthogonal gratings first reached significance at 48 ms before motion onset, indicating an effect of backward masking by motion streaks

Lymph node metastasis in grossly apparent clinical stage Ia epithelial ovarian cancer: Hacettepe experience and review of literature

Background Lymphadenectomy is an integral part of the staging system of epithelial ovarian cancer. However, the extent of lymphadenectomy in the early stages of ovarian cancer is controversial. The objective of this study was to identify the lymph node involvement in unilateral epithelial ovarian cancer apparently confined to the one ovary (clinical stage Ia). Methods A prospective study of clinical stage I ovarian cancer patients is presented. Patient's characteristics and tumor histopathology were the variables evaluated. Results Thirty three ovarian cancer patients with intact ovarian capsule were evaluated. Intraoperatively, neither of the patients had surface involvement, adhesions, ascites or palpable lymph nodes (supposed to be clinical stage Ia). The mean age of the study group was 55.3 ± 11.8. All patients were surgically staged and have undergone a systematic pelvic and paraaortic lymphadenectomy. Final surgicopathologic reports revealed capsular involvement in seven patients (21.2%), contralateral ovarian involvement in two (6%) and omental metastasis in one (3%) patient. There were two patients (6%) with lymph node involvement. One of the two lymph node metastasis was solely in paraaortic node and the other metastasis was in ipsilateral pelvic lymph node. Ovarian capsule was intact in all of the patients with lymph node involvement and the tumor was grade 3. Conclusion In clinical stage Ia ovarian cancer patients, there may be a risk of paraaortic and pelvic lymph node metastasis. Further studies with larger sample size are needed for an exact conclusion.PubMedWoSScopu

The stellar content of the Hamburg/ESO survey. V. The metallicity distribution function of the Galactic halo

We determine the metallicity distribution function (MDF) of the Galactic halo by means of a sample of 1638 metal-poor stars selected from the Hamburg/ESO objective-prism survey (HES). The sample was corrected for minor biases introduced by the strategy for spectroscopic follow-up observations of the metal-poor candidates, namely "best and brightest stars first". [...] We determined the selection function of the HES, which must be taken into account for a proper comparison between the HES MDF with MDFs of other stellar populations or those predicted by models of Galactic chemical evolution. The latter show a reasonable agreement with the overall shape of the HES MDF for [Fe/H] > -3.6, but only a model of Salvadori et al. (2007) with a critical metallicity for low-mass star formation of Z_cr = 10^{-3.4} * Z_Sun reproduces the sharp drop at [Fe/H] ~-3.6 present in the HES MDF. [...] A comparison of the MDF of Galactic globular clusters and of dSph satellites to the Galaxy shows qualitative agreement with the halo MDF, derived from the HES, once the selection function of the latter is included. However, statistical tests show that the differences between these are still highly significant. [ABSTRACT ABRIDGED]Comment: Accepted for publication in A&

Negative parental responses to coming out and family functioning in a sample of lesbian and gay young adults

Parental responses to youths' coming out (CO) are crucial to the subsequent adjustment of children and family. The present study investigated the negative parental reaction to the disclosure of same-sex attraction and the differences between maternal and paternal responses, as reported by their homosexual daughters and sons. Participants' perceptions of their parents' reactions (evaluated through the Perceived Parental Reactions Scale, PPRS), age at coming out, gender, parental political orientation, and religiosity involvement, the family functioning (assessed through the Family Adaptability and Cohesion Evaluation Scales, FACES IV), were assessed in 164 Italian gay and lesbian young adults. Pearson correlation coefficients were calculated to assess the relation between family functioning and parental reaction to CO. The paired sample t-test was used to compare mothers and fathers' scores on the PPRS. Hierarchical multiple regression was conducted to analyze the relevance of each variable. No differences were found between mothers and fathers in their reaction to the disclosure. The analysis showed that a negative reaction to coming out was predicted by parents' right-wing political conservatism, strong religious beliefs, and higher scores in the scales Rigid and Enmeshed. Findings confirm that a negative parental reaction is the result of poor family resources to face a stressful situation and a strong belief in traditional values. These results have important implications in both clinical and social fields