Stellar abundances and presolar grains trace the nucleosynthetic origin of molybdenum and ruthenium

This work presents a large consistent study of molybdenum (Mo) and ruthenium (Ru) abundances in the Milky Way. These two elements are important nucleosynthetic diagnostics. In our sample of 71 Galactic metal-poor field stars, we detect Ru and/or Mo in 51 of these (59 including upper limits). The sample consists of high-resolution, high signal-to-noise spectra covering both dwarfs and giants from [Fe/H]=-0.63 down to -3.16. Thus we provide information on the behaviour of Mo I and Ru I at higher and lower metallicity than is currently known. We find a wide spread in the Mo and Ru abundances, which is typical of heavy elements. This indicates that several formation processes, in addition to high entropy winds, can be responsible for the formation of Mo and Ru. The formation processes are traced by comparing Mo and Ru to elements (Sr, Zr, Pd, Ag, Ba, and Eu) with known formation processes. We find contributions from different formation channels, namely p-, slow (s-), and rapid (r-) neutron-capture processes. Molybdenum is a highly convolved element that receives contributions from several processes, whereas Ru is mainly formed by the weak r-process as is silver. We also compare our absolute elemental stellar abundances to relative isotopic abundances of presolar grains extracted from meteorites. Their isotopic abundances can be directly linked to the formation process (e.g. r-only isotopes) providing a unique comparison between observationally derived abundances and the nuclear formation process. The comparison to abundances in presolar grains shows that the r-/s-process ratios from the presolar grains match the total elemental chemical composition derived from metal-poor halo stars with [Fe/H]~ -1.5 to -1.1 dex. This indicates that both grains and stars around and above [Fe/H]=-1.5 are equally (well) mixed and therefore do not support a heterogeneous presolar nebula... Abridged.Comment: 18 pages, 12 figures, accepted by A&

Resisting aggression : Graphic re-presentations for other bodies

These chapters consider how art can provide a space for wider critical debate on established patriarchal power relations, which have operated in Western culture since the Enlightenment period. As a female artist, I want to explore the space in art of both the female body and the community body. This work seeks to position the female body within the form of her subjectivity, to destabilize patriarchal strongholds through the displacement of the traditionally aestheticised female nude”. That is, I examine the (historicized) notion of a “subject” and the representation of an object”, and understand the female nude” as a representation of patriarchal dominance to this day. I use my art work: of women to explore recent feminist theory that investigates these historicized notions, hoping to present images that critique rather than wholly participate in the tradition of objectifying women without question. Ultimately, I move to a broader field, to incorporate an idea of a community body that is embracing of those bodies culturally precluded from subjective empowerment. My attention is specifically focused on the remediation of the once derelict land and polluted waterways of East Perth, to the pristine condition of what is now an exclusive corporate and residential site. I intend to address my art to the many marginalized bodies, traditionally and presently obstructed from subjective representation within our Western culture. In bringing both bodies together, my art aims to help disrupt the patriarch from his central subjective stronghold. Chapter 1 explores the (assumed) privileged gaze of the Western male artist (and my own naive participation in this practice). which transforms the deformed physical matter” of women into the iconic , conceptual form of the patriarch\u27s Woman . Chapter 2 examines the space for a female voice that recent psychoanalytic theory evokes in challenging the conventions of patriarchy. At this point in particular, my praxis seeks to reflect this emergence for women, as reconnections to the matter of the maternal body are made. Chapter 3 investigates how feminist theory resists the patriarchal icon for female beauty (in the classical nude ), through its representation of new bodily images and identities for women. Subsequently, I journey in my visual practice in responding to this resistance , and focus specifically on the feminist notion of ambiguity for female self-expression, as a means to subversively obstructing patriarchal hegemony. Chapter 4 articulates the significance of desire for women in their discovery of themselves at an intimate level, without the intervention of masculine visual penetration. I represent this intimacy (this divinity for women), through tactile qualities in my practice, which serve to connect women to themselves, whilst interrupting the penetration of the patriarchal gaze. Finally, Chapter 5 shows how the resistance and corporeality of the female body comes to symbolize the existence of the “community body that works to reclaim a presence (a place of domicile) within the redeveloped site of East Perth

The Effect of Individual or Group Guidelines on the Calibration Accuracy of High School Biology Students

The effect of individual or group guidelines on the calibration accuracy of high school biology students was investigated. The study was conducted with 102 International Baccalaureate Middle Years Program biology students in a public school setting. The study was carried out over three testing occasions. Students worked in group or individual settings with and without calibration guidelines. Four intact classes were randomly assigned to one of four conditions: groups calibrating without guidelines; groups calibrating with guidelines; individuals calibrating without guidelines; individuals calibrating with guidelines. The students participated in the calibration activities one block before they actually took each of the three tests. On the day of each test, immediately before taking the test, each student made predictions as to what they thought they would score on the test. Immediately after taking the test each student made postdictions on what they thought they scored on the test. Calibration accuracy was determined by calculating the difference between prediction and postdiction scores and the actual test score achieved. The results indicated that students who calibrated in groups showed trends of more accurate calibration predictions. Although one testing intervention showed significant results for postdiction accuracy, the other two testing interventions showed varied results. Students who calibrated in groups achieved higher scores on tests than did students who calibrated individually. In addition, guidelines were shown to be a significant factor in increasing achievement for students who calibrated individually. For students calibrating in groups guidelines had little impact. The results support the need for more research in metacognition and calibration techniques in order to improve student academic success

The influence of field margin characteristics on syrphid abundance

Field margins have an important ecological role in agroecosystems including hosting beneficial insect such as syrphids. However, little is known of syrphid preferences for different types of field margins. Syrphids were sampled in field margins in an organic agroecosystem to test the hypothesis that syrphid abundance in field margins depends not only on the floral resource abundance but also on field margin component type, field margin complexity, and adjacent land-use type. Floral resource abundance had the greatest influence on the number of syrphids surveyed. Field margin characteristics were deemed to effect syrphid abundance both independently of their effect on floral resources and by altering floral resource abundance. Syrphids were more abundant in field margins adjacent to cropped fields than those adjacent to grazed fields or roads. More syrphids were found in ditch components than in tree or grass strip components. The influence of floral resources on syrphid abundance varied depending on their botanical families, although no significant differences were observed for the effect of botanical family floral resource index on syrphid abundance. These findings demonstrate that field margin characteristics play an important role in facilitating plant–syrphid interactions and offer an insight in agroecosystem management for the promotion of beneficial insects. The influence of field margin characteristics on other beneficial insect groups should also be investigated

Observation of centimetre-scale argon diffusion in alkali feldspars: implications for ⁴⁰Ar/³⁹Ar thermochronology

New data from a gem-quality feldspar from Itrongay, Madagascar, record naturally occurring 40Ar/39Ar age profiles which can be numerically modelled by invoking a single diffusion mechanism and show that microtexturally simple crystals are capable of recording complex thermal histories. We present the longest directly measured, naturally produced 40Ar*-closure profiles from a single, homogeneous orthoclase feldspar. These data appear to confirm the assumption that laboratory derived diffusion parameters are valid in nature and over geological timescales. Diffusion domains are defined by crystal faces and ancient cracks, thus in gem-quality feldspars the diffusion domain size equates to the physical grain size. The data also illustrate the potential of large, gem-quality feldspars to record detailed thermal histories over tens of millions of years and such samples should be considered for future studies on the slow cooling of continental crust

Assessing Connections between Young Children’s Affinity for Nature and Their Experiences in Natural Outdoor Settings in Preschools

The purposes of this research were to: develop a reliable measure of children’s affinity for nature or “biophilia”; determine whether young children’s biophilia was related to the “green-ness” of the outdoor play area of the preschool they attend; examine whether demographic variables are associated with children’s biophilia; and determine whether demographic variables predict children’s enrollment in nature-oriented programs. We recruited children from ten early childhood education programs—six that had outdoor play spaces with many natural elements and four that had few or none of these elements. One hundred fourteen preschool-aged children completed an 11-item measure of biophilia that included preferences for play locations (outdoors or indoors, during day and evening), enjoyment of sensory aspects of nature (viewing wildlife, listening to birds), exploring nature (digging for worms, examining insects), and curiosity about nature (learning about wild animals). Total biophilia scores of children attending preschools with and without natural playground elements were compared via ANOVA, which revealed no significant differences as a function of preschool playground type (nature, non-nature). Maternal education and family income were not associated with children’s biophilia scores; however, children whose mothers completed more education and reported higher family income were more likely to be enrolled in programs with natural outdoor play spaces, suggesting that children who are disadvantaged in these factors may not have equal access to programs with natural play spaces

Abundances and kinematics of carbon-enhanced metal-poor stars in the Galactic halo*; A new classification scheme based on Sr and Ba

Carbon-enhanced metal-poor (CEMP) stars span a wide range of stellar populations, from bona fide second-generation stars to later forming stars that provide excellent probes of, e.g., binary mass transfer. Here we analyse 11 metal-poor stars of which 10 are CEMP stars. Based on high signal-to-noise (SNR) X-Shooter spectra, we derive abundances of 20 elements (C, N, O, Na, Mg, Ca, Sc, Ti, Cr, Mn, Fe, Ni, Sr, Y, Ba, La, Ce, Pr, Nd, Eu). From the high SNR spectra, we trace the chemical contribution of the rare earth elements (REE) from various production sites, finding a preference for metal-poor low-mass AGB stars of 1.5Mo in CEMP-s stars, while CEMP-r/s stars may indicate a more massive AGB contribution (2-5Mo). A contribution from the r-process - possibly from neutron star mergers (NSM), is also detectable in the REE abundances, especially in the CEMP-r/s. Combining spectra with Gaia DR2 astrometric data indicates that all but one star in our sample (and most literature stars) belong to the Galactic halo. They exhibit a median orbital eccentricity of 0.7, and are found on both pro- and retrograde orbits. The orbital parameters of CEMP-no and CEMP4s stars are remarkably similar in the 98 stars we study. A special CEMP-no star, with very low Sr and Ba content, possesses the most eccentric orbit among the stars in our sample, passing close to the Galactic centre. Finally, we propose an improved scheme to sub-classify the CEMP stars, making use of the Sr$/$Ba ratio, which can also be used to separate very metal-poor stars from CEMP stars in 93 stars in the metallicity range $-4.2<$[Fe/H]$<-2$. The Sr/Ba ratio can also be used for distinguishing CEMP-s,-r/s and -no stars. The Sr/Ba ratio is also a powerful astro-nuclear indicator, as AGB stars exhibit very different Sr/Ba ratios, compared to fast rotating massive stars and NSM, and it is fairly unbiased by NLTE and 3D corrections.(abridged)Comment: 15 pages, 4 pages appendix, 11 figures, accepted for publication in A&

Decision Making in the Shadow of Death

It is often assumed that decision-making is a completely rational process. In reality, of course, numerous heuristics and biases influence the way we think and the decisions we make in clinical, research and policy contexts. While Blumenthal-Barby elegantly describes various types of heuristics and biases, and the effect that they may have on one’s autonomy, we suggest that there is insufficient attention given to the heuristics that may be most determinative in medical contexts – hope, and its attendant emotion, fear. Our insights are drawn from an empirical study of the legal and ethical 'limits' of consent in the setting of decision-making around a high risk medical interventions (bone marrow transplantation - BMT) which revealed that every formal element of consent is shaped or transmogrified by a patient’s ‘hope for a future’. In this qualitative study we examined the accounts of patients with haematological malignancies, their loved ones and the health care professionals caring for them regarding the decision to offer, and go through with, BMT - where BMT provided the possibility of ‘cure’ but carried a high risk of death (particularly in the first year post-BMT) and long-term morbidity. While the heuristics described by Blumenthal-Barby were evident in the narratives of all of the participants in this study and undoubtedly impacted upon understanding, intentionality and effective autonomy, what was most striking was the degree to which hope, and its attendant emotion, fear, impacted upon decision-making and overwhelmed all other considerations that may have been relevant to the decision to proceed to BMT